All these substances are part of body fluids, muscles and glandular tissue. Their molecules break down into electrically charged ions. Electric current in the human body does not move in a straight line. This movement and conduction of current depends on the presence of good conductors and the amount of fat tissue that does not conduct current well.
Electroplating is harmful to health
During the process electrolysis, especially during the so-called polarization phenomenon electrical voltage system, there is a more or less significant release of bubbles of hydrogen, oxygen and other gases from the surface of the bath. Together with them, the electrolyte itself is carried into the air in the form of fog, polluting the air with toxic and irritating substances (chromic anhydride, hydrogen cyanide, etc.). An increase in the density of the current used in galvanic baths, the concentration of the electrolyte and the temperature of the bath, as a rule, is accompanied by an increase in the release of hydrogen and entails the release of the electrolyte into the room air.
Environmental problems of electroplating production
Soviet atavism is still alive in modern industry - consumer attitude to natural resources. This is noticeable even at the stage of training engineers and workers. Unfortunately, it is believed that the capacity of nature is limitless, that it is capable of absorbing all the dirt and waste products of production, accumulating it within itself and forever sealing it in its depths. A kind of unlimited toilet. But the reality is that sooner or later, this toilet gets clogged and everything comes out. This happens either explicitly - man-made accidents, emissions, or implicitly - the poisoning of waste into the environmental medium: water, soil, air, from where everything eventually enters the body of unsuspecting people. And galvanic production, for the most part, has the second type of effect. How many people even know about it? How many people know about the harm that electroplating waste causes to their health? But these pollution are in FIRST place, surpassing oil spills and radiation!
Electroplating is harmful to health
Safe electroplating
Electroplating is a science that allows, by electrodeposition of a thin galvanic layer, to impart new properties to a metal. It turns out quickly and beautifully. Alas, everything is not so simple: modern galvanic production occupies one of the leading places in terms of production hazards.
Safety precautions
Nitric acid leads to very painful burns that are difficult and take a long time to heal. When metals are etched, nitrogen oxides are formed, which damage the blood and nervous system. Nitric acid is a strong oxidizing agent - clothes doused with this acid can catch fire. Nitric acid vapors irritate the mucous membrane of the eyes and respiratory tract and can cause conjunctivitis and corneal damage, pneumonia and bronchial inflammation, as well as pulmonary edema.
Electroplating workshop harmfulness
Let's figure it out in order. It seems that one of the biggest dangers in electroplating production is the release of nitrogen oxides, sulfuric acid, and trichlorethylene. When working for a long time in a room where the air is saturated with these substances, this certainly affects the internal state of the body. This is also associated with possible damage to the nasal mucosa, especially when constantly working with chromium.
Electroplating is harmful to health
Galvanics is a branch of electrochemistry that includes two subsections that study the deposition of electrolytes on the surface of a metal for different purposes. For example, corrosion protection. In real life, the process of coating products, for example, with chromium or copper, has the same name. Recently, decorative electroplating at home has become very popular, which brings considerable income to those who are willing to work.
Electroplating workshop harmfulness
A known danger is the release of trichlorethylene vapors from the process of degreasing products in baths. However, from a hygienic point of view, direct contact with these products and the possibility of their impact on the body through the skin are of greatest importance in cases of weak mechanization of production processes in galvanic shops. Contact with an unprotected skin surface leads to skin diseases, and inhalation of certain substances, such as chromic anhydride during the chrome plating process, leads to damage to the nasal mucosa, including perforation of the cartilaginous part of the nasal septum.
Harm to health
I worked for two days. Still alive)) Only silver plating and the degrease line work. There are no strange odors, the hoods work. The lye bath alone will evaporate. And so it’s normal, after work I feel great. Only the galvanizer who teaches me scares me of cancer and impotence, but everything is bad)
Electroplating is harmful to health
The most effective remedy is an emulsion of the following composition, %: Sunflower oil - 12 Ammonia, 10% aqueous solution - 12 Neutral solutions of potassium sodium tartrate - Rochelle salt - are widely used for clearing gold leaf. Technical operations require professional skills.
Occupational hygiene of galvanic production worker
Other elements, including metals, play important roles. They are divided into macro, micro, ultramicroelements and are contained in the body in sizes from kilograms to micrograms. Harm from them occurs when they enter the body one-time or systemically in quantities exceeding physiologically acceptable ones. To control these quantities, standards for maximum permissible concentrations of chemical compounds - MAC - were invented. Without going into the intricacies of dividing MPCs into categories, let’s say that in Russia they are among the most stringent.
They accumulate in the body and leave it very slowly. Chromium, for example, can be absorbed even through the skin and exhibits carcinogenic effects in extremely low concentrations. Here we note that hexavalent chromium is the most harmful - the main component of chromium plating electrolytes, as well as zinc passivation.
Electroplating is harmful to health
Processes associated with the use of toxic substances, grinding and polishing materials are especially harmful. To ensure safe working conditions when applying galvanic coatings, a system of measures has been developed aimed at further improving working conditions.
What are the dangers of the galvanic process?
Electroplating requires a specialized manufacturing process and skilled personnel. On the galvanizing line in galvanic baths, electrochemical degreasing, pickling in hydrochloric acid, removal of pickling sludge, cyanide-free galvanizing, and passivation with intermediate rinsing in hot and cold water of steel parts are carried out.
Moscow State Technological University "STANKIN"
Department of “Ecological Engineering and Life Safety”
EXPLANATORY NOTE
FOR COURSE WORK IN THE DISCIPLINE
"INDUSTRIAL SANITATION AND OCCUPATIONAL HYGIENE"
ON THE TOPIC: “OCCUPATIONAL HYGIENE OF GALVANIC PRODUCTION WORKERS”
Completed by: student of group T-7-10
Filatova V.A.
Submission date: December 18, 2009
Checked by: Butrimova E.V.
Moscow, 2009
Introduction
Chapter 1. Galvanic production
1.1 Electroplating and metal coating
1.2 Hygienic characteristics of working conditions
Chapter 2. OVPF of galvanic production
2.1 OVPF when applying metal coatings
2.2 Characteristics of some harmful substances
2.3 Noise and vibration
Chapter 3. Methods and means for preventing CVPF in galvanic production
3.1 Ventilation of galvanizing shops
3.2 Wastewater treatment from electroplating workshops
3.3 General preventive measures
Conclusion
Application
Bibliography
INTRODUCTION
Modern galvanic production occupies one of the leading places among air pollutants in the working area. Electroplating workshops use substances, most of which are harmful. Production conditions are characterized by high humidity, significant concentrations of harmful vapors and gases, dispersed mists and splashes of electrolytes. Occupational diseases (asthma, allergies, ulcers of internal organs, blindness and loss of smell) received by service personnel in these workshops are largely associated with human exposure to harmful production factors at work. The main impact on human health is caused by liquid, gaseous and dust aerosols in the air of the working area. At the same time, the productivity of workers is significantly reduced and the quality of products deteriorates. Therefore, galvanizing workshops are hazardous areas of production, where constant compliance with precautions and safety regulations is necessary.
1. GALVANIC PRODUCTION
1.1 GALVANIC AND METAL COATING
Electroplating- electrolytic deposition of a thin layer of metal on the surface of a metal object to protect it from corrosion, increase wear resistance, protect against cementation, for decorative purposes, etc. The resulting galvanic coatings - deposits - must be dense and fine-grained in structure. To achieve a fine-grained structure of deposits, it is necessary to select the appropriate electrolyte composition, temperature conditions and current density.
Galvanic coating of metal- this is a great way to avoid many problems and increase the service life of equipment, units and other devices. Electroplating using chrome or nickel plating requires a special production process and qualified personnel.
Electroplating is an electrochemical process in which a layer of metal is deposited on the surface of the product. A solution of salts of the applied metal is used as an electrolyte. The product itself is the cathode, the anode is a metal plate. When current passes through the electrolyte, metal salts disintegrate into ions. Positively charged metal ions are directed to the cathode, resulting in electrodeposition of the metal.
The thickness, density, structure of galvanic coatings can be different depending on the composition of the electrolyte and the conditions of the process - temperature, current density. For example, by varying the ratio of these two parameters, you can obtain a shiny or matte chrome coating; for shiny nickel plating, shine formers - sulfo compounds - are added to the electrolyte.
Decorative coatings have a small thickness, fine-grained structure and sufficient density. To ensure strong adhesion of the coating to the product, it is necessary to carefully prepare the surface, which includes mechanical processing (grinding and polishing), removal of oxides and degreasing of the surface. After coating, the product is washed and neutralized in an alkaline solution.
Each technological process of electroplating metal coatings consists of a number of individual operations that can be divided into 3 groups:
1. Preparatory work. Their purpose is to prepare the metal (its surface) for electroplating. At this stage technological process grinding, degreasing and etching are carried out.
2. The main process, the purpose of which is to form a suitable metal coating using the electroplating method.
3. Finishing operations. They are used to refine and protect galvanic coatings. Passivation, painting, varnishing and polishing are most often used for these purposes.
Electroplating production is capable of producing many types of different coatings, which may include:
Chrome plating
Chrome coatings are among the most versatile in terms of their functional applications. With their help, they increase the hardness and wear resistance of the surface of products and tools, and restore worn parts. This is due to the presence on its surface of a very dense passivating film of an oxide nature, which is easily restored at the slightest damage. Widely used for corrosion protection and decorative finishing surfaces of products. Depending on the process mode, coatings with different properties can be obtained.
Galvanizing
Zinc coating protects ferrous metals from corrosive destruction not only mechanically, but also electrochemically. Zinc coatings are widely used to protect machine parts and fasteners from corrosion; they are used to protect against corrosion water pipes, feed tanks in contact with fresh water at a temperature not exceeding 60-70 ° C, as well as to protect ferrous metal products from gasoline and oils, etc. In an environment saturated with sea fumes, zinc coatings are not durable.
Cadmium plating
The chemical properties of cadmium are similar to those of zinc, but it is more chemically stable. Unlike zinc, cadmium does not dissolve in alkalis. Coating, like zinc, is used to protect ferrous metals from corrosion. The peculiarity of cadmium coating is that it provides electrochemical protection of steel in tropical conditions. Cadmium is much more ductile than zinc, so parts with threaded connections are preferred to be plated with cadmium. However, parts in contact with fuels should not be coated in atmospheres containing volatile organic matter(drying oil, varnishes, oils) and sulfur compounds.
Nickel plating
Electroless nickel plating
Chemical nickel coating containing 3-12% phosphorus, compared to electrolytic coating, has increased anti-corrosion resistance, wear resistance and hardness, especially after heat treatment. Has low porosity. The main advantage of the chemical nickel plating process is the uniform distribution of metal over the surface of a relief product of any profile.
Electrochemical nickel plating
Nickel is used to coat products made of steel and non-ferrous metals (copper and its alloys) to protect them from corrosion, decorative surface finishing, increase resistance to mechanical wear and for special purposes. Nickel coatings have high anti-corrosion resistance in the atmosphere, in alkali solutions and in some organic acids, which is largely due to the strong ability of nickel to passivate in these environments. The nickel coating is highly polished and can be easily brought to a mirror finish.
Tin plating
The main areas of application of tin coatings are protecting products from corrosion and ensuring solderability of various parts. This metal is stable in an industrial atmosphere, even containing sulfur compounds, in water, and in neutral environments. In relation to products made from copper alloys, tin is an anodic coating and protects copper electrochemically. Tin coatings are extremely ductile and can easily withstand flaring, stamping, and bending. The coatings have good adhesion to the base, provide good corrosion protection and a beautiful appearance. Freshly deposited tin is easily soldered using alcohol-rosin fluxes, but after 2-3 weeks its ability to solder sharply deteriorates.
Copper plating
Copper coatings are most often used to save nickel as a sublayer during nickel and chrome plating. Due to the intermediate coating of steel and cast iron with copper, better adhesion between the base metal and the coating metal is achieved and the harmful effects of hydrogen are reduced. Copper coatings are also widely used for local protection during cementation and galvanoplasty. Copper coatings are well polished, which is important for decorative and protective coatings. Well-equipped galvanizing shops are available in almost all machine-building and metalworking plants.
Silvering
Silver has high electrical conductivity, reflectivity and chemical stability, especially when exposed to alkaline solutions and most organic acids. Therefore, silver coatings are used mainly to improve the electrically conductive properties of the surface of current-carrying parts, to give the surface high optical properties, to protect chemical equipment and instruments from corrosion under the influence of alkalis and organic acids, as well as for decorative purposes.
Most common galvanizing and copper plating.
The general system of measures for applying galvanic coatings is established by GOST 12.3.008-75 and SSBT “Production of metallic and non-metallic coatings. General requirements security." The main requirements are automation and sealing of processes - sources of dangerous and harmful production factors.
1.2 HYGIENIC CHARACTERISTICS OF WORKING CONDITIONS
Almost all metal coating processes are sources of release of harmful chemicals into the air. The physical state of harmful emissions (in the form of gases, vapors, dust) and their quantitative characteristics depend on the technology conditions, and in some cases on compliance with the operating mode.
For example, during electroplating processes, an unreasonable increase in current density, solution concentration and an increase in electrolyte temperature lead to the rapid release of hydrogen and oxygen with the release of electrolyte mist and decomposition products into the air.
At high temperatures of the etching and galvanic solution, it evaporates intensely, polluting the air. The greatest danger is the release of cyanide compounds into the air (hydrogen cyanide vapor, KCN solution, NaCN) during silver cyanide, copper plating, galvanizing, cadmium plating in alkaline cyanide baths. The reasons for the release of cyanide into the air are a possible change in the pH of the electrolyte from sharply alkaline to acidic. Under normal conditions, a theoretically acidic environment is created by the influence of air on the CO2 solution, as well as the possible dissociation of water under the influence of electric current on H+ and OH- ions.
These conditions, however, in practice do not entail massive releases of hydrogen cyanide, since the environment remains alkaline. But in emergency situations (acids entering cyanide baths, combining ventilation air flows or wastewater from cyanide and acid pickling baths), hydrogen cyanide may be released in dangerous concentrations.
Sulfuric anhydride, nitrogen oxides, and hydrogen chloride released during etching processes (respectively, when using sulfuric, nitric, and hydrochloric acid) are now rarely detected in the air of industrial premises due to the implementation of effective technological and sanitary measures.
However, in some emergency cases, their release into the air of the working area may occur. In addition to air pollution with chemically harmful substances, the direct effect on the skin and mucous membranes of electrolytes (during electroplating), degreasing and etching solutions, alkalis and acids during oxidation, etc., also has a negative impact.
Up to 10% of workers in galvanic and other metal coating shops are busy dosing, preparing and mixing bulk components, solutions, and electrolytes. These personnel are sometimes exposed to dry powders or concentrated (before dissolving or diluting) toxic substances (e.g. cyanide salts, chromium, acids).
The air environment of electroplating shops can be polluted with substances that replace obviously toxic ones (for example, ethylenediamine and polyethylene polyamines instead of cyanide salts in copper cyanide plating) or play an auxiliary role in the coating processes (ammonia when ammonium sulfate is used in a number of processes for alkalizing the solution).
Vapors of molten metals in a number of the processes listed above (lead, zinc) can cause a number of specific pathological changes.
Organic solvents and chlorinated hydrocarbons contained in degreasing solutions can also lead to occupational poisoning if inhaled continuously.
Of particular importance in the practice of electroplating is the exposure of workers to chromic anhydride, which can manifest itself in the form of lesions of the nasal mucosa. Depending on the concentration of chromic anhydride in the air, the symptoms are different: at low concentrations, 2 - 3 times higher than the maximum permissible concentration, a runny nose, irritation of the nasal mucosa, and minor nosebleeds were noted. At higher concentrations, necrosis of areas of the mucous membrane, ulcers, and even perforations of the nasal septum appeared. .
The release of acid and alkali vapors into the air has an irritating effect on the mucous membranes of the respiratory tract, eyes, and destroys tooth enamel. In galvanic production areas, the most adverse effects are exerted by nickel and chromium salts, which have a sensitizing effect. Their effects are especially pronounced after previous contact with degreasing alkalis and organic solvents.
The clinical picture of occupational skin disease resulting from exposure to nickel salts is similar to eczema localized on the flexor surfaces of the forearm; when exposed to chromium salts, eczema and dermatitis were identified. These diseases easily recur when contact with sensitizers is resumed.
Acids and alkalis cause characteristic burns when they come into contact with the skin. Solvents and chlorinated hydrocarbons are irritating and cause (gasoline) chronic eczema, dermatitis, dry skin, cracks.
Sometimes skin lesions from exposure to chemically active substances are observed in persons to whom parts are received in further technological processes and operations (assemblers). This is due to the presence of a certain amount of acids or chromic anhydride on the surface of the parts.
2. OVPF GALVANIC PRODUCTION
In electroplating shops, sources of danger are the technological processes of surface preparation, preparation of solutions and electrolytes, and application of coatings. Surface cleaning methods are characterized by increased dust, noise and vibration. Alkalies, acids, and salts used to prepare solutions can cause poisoning or occupational illness when exposed to the body. Using hand-held vibration tools for grinding surfaces can cause vibration disease. Working in ultrasonic cleaning baths involves exposure of the worker to sound and ultrasonic vibrations. In addition, the abundance of rinsing baths in the room creates increased humidity. Normal working conditions are ensured by good lighting, supply and exhaust ventilation and maintaining normal air temperature in the workshop.
2.1 OVPF WHEN APPLYING METAL COATINGS
Table 1. List of dangerous and harmful production factors when applying metal coatings
|
Operation or process |
||
|
Preparing the surface of parts before applying metal coatings |
||
|
Grinding and polishing |
Metal dust paste based on chromium oxide |
|
|
Hydrosandblasting |
Solutions of sodium nitrate or chrompic |
|
|
Shot blasting |
Metal dust |
|
|
Underwater polishing |
Hot soapy solution: slaked lime emulsion; vapors of sulfuric acid, potassium chromium |
|
|
Galtovka |
Splashes of soda ash solution, potassium chromium |
|
|
Vibroabrasive processing |
||
|
Degreasing |
||
|
organic solvents |
Organic solvent vapors Caustic soda vapor |
|
|
alkaline solvents |
Vapors of alkaline solutions, splashes of alkalis |
|
|
electrochemical |
||
|
Activation |
Vapors of sulfuric and hydrochloric acids, splashes of acids |
|
|
Etching: |
||
|
chemical |
Vapors of sulfuric, hydrochloric and nitric acids, nitric oxide. Increased level of ultrasound |
|
|
cathode |
Hydrogen fluoride, vapors of hydrochloric, sulfuric and nitric acids, nitric oxide |
|
|
Vapors of sulfuric and phosphoric acids, chromic anhydride, acid splashes |
||
|
Chemical polishing |
Vapors of chromic anhydride, sulfuric, hydrochloric and orthophosphoric acids, nitric oxide |
|
|
Electrochemical |
Vapors of chromic anhydride, sulfuric, orthophosphoric acids, |
|
|
polishing |
nitrogen oxides |
|
|
Ultrasonic Removal of oxide films, dirt |
Splashes of alkaline solutions. Increased level of ultrasound Electromagnetic radiation |
|
|
Preparation of solutions of acids and alkalis |
Acid vapors, hydrogen fluoride and chloride, alkali solutions |
|
|
Application of metal coatings. Electrochemical method |
||
|
Galvanizing in electrolytes: |
||
|
Acid fumes |
||
|
cyanide |
Hydrocyanic acid, cyanide compounds |
|
|
ammonia |
Zinc compounds, ammonia |
|
|
zincate |
Zinc compound |
|
|
Cadmium plating in electrolytes: |
||
|
Borofluoric acid |
||
|
Vapors of alkali and hydrocyanic acid |
||
|
cyanide |
Splashes of alkali and acid |
|
|
in electrolytes: |
||
|
Tin compounds, sulfuric acid vapors |
||
|
alkaline |
Alkali vapors, alkali splashes |
|
|
Leading |
Lead compounds, pairs of borofluorohydrogen and fluorosilicic acids |
|
|
Copper plating in electrolytes: |
||
|
cyanide |
Copper compounds, cyanide compounds, hydrocyanic acid |
|
|
non-cyanide alkaline |
Alkali fumes and splashes |
|
|
non-cyanide acidic |
Vapors of sulfuric, borofluoric, hydrofluorosilicic acids; electrolyte splashes |
|
|
Nickel plating |
Electrolyte splashes |
|
|
Chrome plating |
Chromic anhydride fumes, sulfuric acid fumes and splashes |
|
|
Ironing |
Hydrochloric acid fumes, ammonia |
|
|
Silvering in cyanide electrolytes |
Splashes of silver salts, cyanide compounds, hydrocyanic acid vapors |
|
|
Gilding in cyanide electrolytes |
Hydrocyanic acid vapor |
|
|
Palladizing |
||
|
Rhodium plating |
||
|
Chemical method |
||
|
Copper plating |
Acid fumes, ammonia, electrolyte splashes |
|
|
Nickel plating |
Nickel compounds, ammonia vapors, acids |
|
|
Silvering |
Ammonia, sulfuric acid vapor |
|
|
Anodic oxidation |
Vapors of sulfuric, oxalic, phosphoric acids, dichromates, ammonia |
|
|
Oxidation ferrous metals |
Nitrogen oxides, alkali and phosphoric acid vapors, alkali splashes, nitrite salts |
|
|
Aluminum oxidation and its alloys |
Vapors of chromium compounds, alkalis or hydrogen fluoride |
|
|
Oxidation of magnesium and its alloys |
||
|
Chromating |
Acid fumes, nitrogen oxides, chromium compounds, acid splashes |
|
|
Phosphating ferrous metals |
Phosphoric acid fumes, hydrogen fluoride, zinc compound |
|
|
Phosphating of non-ferrous metals |
Hydrogen fluoride, zinc compounds, nitric and nitrous acid salts |
|
|
Physical methods |
||
|
Hot way: |
||
|
Ammonia vapors, tin oxides; splashes of molten tin |
||
|
tin-lead alloy |
Vapors and oxides of tin and lead |
|
|
galvanizing |
Zinc oxide vapor |
|
|
Diffusion method: |
||
|
zinc |
Zinc dust |
|
|
silicon |
Silicon dust |
|
|
aluminum |
Dust of aluminum and its oxides |
|
|
Metallization Coating method: |
||
|
zinc |
Increased dust content with metal dust |
|
|
cadmium |
||
|
aluminum |
||
|
lead |
||
|
tin |
||
|
nickel |
||
2.2 CHARACTERISTICS OF SOME HAZARDOUS SUBSTANCES FROM PRODUCTION
The most harmful and dangerous substances in handling are:
NATPCAUSIC (NaOH)
If the solution or dust gets on the skin, a soft scab will form. Ulcers and eczema occur, especially in the articular folds of the fingers. Getting even the smallest amounts of NaOH into your eyes is dangerous; Not only the cornea is affected, but also due to the rapid penetration of NaOH into the depths, the deep parts of the eye also suffer. The outcome may be blindness. In case of contact with skin, wash the affected area with a stream of water for 10 minutes, then apply a lotion with a 5% solution of acetic or citric acid. In case of contact with eyes, immediately rinse thoroughly with a stream of water or saline solution for 10 minutes. MPC --0.5 mg/m3.
Personal protection: overalls made of thick fabric, rubber gloves, sleeves, aprons, shoes.
SODA ASH (Na2 CO4 )
When working with soda ash, ulcerations of the nasal mucosa are observed, similar to those that occur under the influence of chromium compounds. Inhalation of dust can cause respiratory irritation and conjunctivitis. When working with solutions for a long time, the following are possible: eczema, skin irritation. A concentrated solution of Na2CO4 causes burns, necrosis, and subsequent clouding of the cornea. MPC --2 mg/m3.
Personal protection: overalls made of thick fabric, rubber gloves, sleeves, apron, shoes.
Hydrochloric acid (HCL)
At high concentrations - irritation of the mucous membranes, especially the nose, conjunctivitis, clouding of the cornea, tingling in the chest, runny nose, cough, chronic poisoning causes catarrh of the respiratory tract, tooth decay, changes in the nasal mucosa and even the disappearance of the nasal septum; gastrointestinal disorders, possible inflammatory skin diseases. Usually the cause of poisoning is not HCL gas, but HCL mist, which is formed when the gas reacts with water vapor in the air.
In case of poisoning, immediately remove the victim to fresh air and remove clothing that restricts breathing. Oxygen inhalation. Rinse eyes, nose, rinse with 2% soda solution. If the eyes are affected, after rinsing, inject 1 drop of 2% novocaine solution into the eyes. If strong acid gets on the skin, immediately wash it with water for 5 minutes. MPC -- 5 mg/m3.
Personal protection: filtering industrial gas mask of grade B, sealed safety goggles. Overalls made of acid-resistant fabric. Mittens and gloves made of resistant rubber. Boots made of acid-resistant rubber.
Hydrocyanic acid (HCN)
Poisoning with hydrocyanic acid and its compounds is possible during ore processing (cyanidation), electroplating of metals, disinsection and deratization of premises, etc. Entering the body through the respiratory tract, less often through the skin, hydrocyanic acid blocks the respiratory enzyme cytochrome oxidase and causes oxygen starvation fabrics. In acute poisoning, irritation of the mucous membranes, weakness, dizziness, nausea, and vomiting are observed; then respiratory disorders predominate - rare deep breathing, painful shortness of breath, slowdown and cessation of breathing occur. In case of chronic poisoning with hydrocyanic acid, concern headache, fatigue, low blood pressure, changes in the electrocardiogram are noted, in the blood there is a decrease in sugar levels and an increased content of hemoglobin, lactic acid, etc. The effect of potassium and sodium cyanide on the skin can cause the formation of cracks and the development of eczema.
Personal protection: filtering industrial gas mask, sealed safety goggles. Overalls made of acid-resistant fabric. Mittens and gloves made of resistant rubber. Boots made of acid-resistant rubber.
AMMONIA (NH3 )
Ammonia vapors strongly irritate the mucous membranes of the eyes and respiratory organs, as well as the skin. This is what we perceive as a pungent odor. Ammonia vapors cause excessive lacrimation, eye pain, chemical burns of the conjunctiva and cornea, loss of vision, coughing attacks, redness and itching of the skin. When liquefied ammonia and its solutions come into contact with the skin, a burning sensation occurs, and a chemical burn with blisters and ulcerations is possible. In addition, liquefied ammonia absorbs heat when it evaporates, and when it comes into contact with the skin, frostbite of varying degrees occurs. The maximum permissible concentration in the air of the working area of the production premises is 20 mg/m³.
2.3 NOISE AND VIBRATION
The high level of noise and vibration that accompanies the operation of equipment in all areas of production (mechanical engineering, construction, agriculture, etc.) leads to a decrease in labor productivity, deterioration in the quality of products and the well-being of workers. Moreover, with a significant proportion of heavy and unskilled work, these factors (noise and vibration) can cause occupational diseases.
The fight against noise and vibration in electroplating shops is currently receiving increasing attention. This is due to their particularly dangerous impact on the human body, as well as the fact that noise and vibration in workplaces is constantly increasing due to the consolidation of production, the use of equipment and mechanisms of greater power.
Noise in the workshop results from the operation of engines, pumps, and mixers. Noise and vibration have a harmful effect on the human body. With prolonged exposure to noise, not only hearing acuity decreases, but also blood pressure changes, attention weakens, and vision deteriorates. When operating simultaneously, engines, pumps, and mixers do not exceed the permissible sound level in workplaces of 80 dB, according to SN 3223-85, so there is no need to apply sound insulation measures. To reduce the spread of vibration through the building structure caused by the operation of fans and pumps, elastic materials are laid under their base.
3. METHODS AND WITHREMEDIES TO PREVENT AFPFIN GALVANIC PRODUCTIONS
3.1 VENTILATION OF THE PLATING SHOP
There are standards for maximum permissible concentrations of harmful substances in the air of working premises. These standards include quite a lot of substances released during the operation of galvanic equipment (chemical splashes and dust, abrasive dust, solvent vapors, etc.). To ensure that their concentration does not exceed the permissible limit, various measures are used. The most common and most effective of them is to equip the workshop with supply and exhaust ventilation, the purpose of which is to, due to the exchange of air, i.e. suction of contaminated and supply of fresh, maintain the content of harmful substances in the air of the galvanic shop at a level not exceeding the requirements of the maximum permissible concentration.
Ventilation of air can occur due to the difference in its temperature inside and outside the room, through open windows, random cracks, even through walls with relatively porous material, but this so-called natural ventilation is not very productive, and the direction and speed of air movement is difficult to control. Much more effective is forced industrial ventilation, in which air is sucked out or supplied by a power-driven fan. Forced ventilation allows you to suck air with the required intensity directly from places of harmful emissions and supply fresh air, rationally distributing it throughout the room.
The entire supply and exhaust ventilation system of galvanic production, and often the adjacent rooms connected to it, is a single whole in which all air movements in the pipelines and in the room itself are interconnected.
Therefore, any violation of the interdependence provided for by the project by, for example, altering some elements of the air duct or, what is much worse and absolutely unacceptable, connecting additional consumers, not supported by calculations and appropriate design measures, can have a catastrophic effect on the ventilation of the entire room.
The manufacture and alteration of ventilation should be carried out only by qualified specialists, since the serviceability of ventilation is a matter of health and even the life of specialists working in the galvanic shop.
Onboard suction of galvanic equipment
The design of the onboard suction affects not only the efficiency of ventilation, but also the convenience of the galvanizer, and, consequently, his productivity.
Ventilation systems used in electroplating shops are: fume hoods, inside which equipment is installed; exhaust hoods (hoods) installed above equipment, including electroflotators; suction grilles installed on the side of the equipment on its non-working side; side exhausts installed at the level of the upper edge of galvanic baths and surface treatment units. These systems are shown in Fig. 1
Fig.1 Air intake devices of local exhaust systems: exhaust hood (a); fume hood (b); onboard suction (c).
Characteristics of suction devices are presented in Table 2.
Table 2. Characteristics of ventilation suction units used in electroplating shops.
|
Advantages |
Flaws |
Areas of use |
||
|
Pull out drobe |
Well isolates rooms from harmful emissions from equipment located inside the cabinet |
Difficulty in accessing equipment. When working on equipment, a person is in the area of harmful emissions |
When etching non-ferrous metals |
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Exhaust hood (hood) |
Ease of manufacture |
When working on equipment, a person is in a stream of suctioned harmful substances. The air consumption is very high, since it is difficult to avoid unproductive air suction from the sides |
When working in bulk bells with gas-emitting alkaline electrolytes or when cleaning bells from build-up by etching in acids |
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Chernoberezhsky panel (uniform suction panels) |
Little interference with work, especially if the equipment is located against the wall and the panel does not interfere with the passage. Well captures emissions of light gases, such as water vapor |
Requires significant air consumption. Its installation is inconvenient with free-standing equipment |
On rinsing baths with hot water when servicing them on one side. Rarely used in galvanic shops |
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Onboard suction |
Effectively removes splashes and heavy gases and, in most cases, light gases. A worker bending over equipment is out of the area of harmful emissions |
Increases the width of the equipment, making access to the edge of the bathtub opposite to the working one somewhat more difficult |
On all types of electroplating equipment, including even some types of rotating bells and drums |
The principle of operation of the most universal ventilation equipment for galvanic equipment, the “on-board suction”, is that air sucked in at high speed through a narrow intake slit of the suction unit forms a strong horizontal jet (torch) above the surface of the electrolyte solution, which knocks droplets ejected from the solution out of the vertical path and this causes their main mass to fall back into the bath, and the remaining drops and gases are carried away into the ventilation suction.
This work of local ventilation suction is especially clearly observed over a galvanic chrome plating bath, the splashes from which are brightly colored and their path is easy to follow.
Side suctions are most widely used in the electroplating industry because they are convenient, efficient and economical.
3.2 WASTEWATER TREATMENT OF THE PLATING WORKSHOP
The purpose of treatment facilities is to purify wastewater (acid-alkaline, chromium-containing, cyanide, fluorine-containing) after washing operations in galvanic production to the maximum permissible concentrations of harmful substances for heavy metals with subsequent discharge of purified water into the sewerage system or return to reuse in the recycling water supply cycle of the enterprise.
Wastewater from the galvanizing shop flows by gravity to the treatment plant through separate pipelines for each type of pollution. Effluent mixing different types not allowed. The wastewater contains cyanogen, hexavalent chromium, acids, alkalis and salts of heavy metals (nickel, zinc, iron), the content of which, when discharged into the city sewerage system, is limited by sanitary standards.
Wastewater from electrochemical degreasing baths and after pickling baths from the galvanic shop, contaminated with acids, alkalis and heavy metal salts, is chemically purified at factory treatment facilities.
This method of treating acid-base wastewater takes into account the possibility of the presence of heavy metal impurities in acid-base wastewater. The essence of the process of neutralizing acid-base wastewater is the mutual neutralization of these wastewater, followed by their subsequent neutralization with an alkali solution and the precipitation of dissolved metals in the form of hydroxides with a solution of slaked lime.
3.3 GENERAL PREVENTIVE MEASURES
The premises of metal coating shops should primarily be located in one-story buildings. In the case of a multi-story building, the workshops are located on the first floor, and a number of sanitary installations (air ducts, sewer drains, warehouses, etc.) are preferably located below the ground level (in basements). Warehouse premises, dosing departments, areas for electrolyte preparation, surface preparation (etching) must be isolated from each other and provided with the necessary ventilation devices.
The premises are provided with acid-resistant floors made of special asphalt, concrete, wall cladding to a height of 1.5 m from the floor with acid-resistant " ceramic tiles on a special acid-resistant mastic. There should be drains in the floor. The location of galvanic baths using cyanide salts should be provided at the greatest distance from baths with acidic solutions.
The equipment should not occupy more than 20% of the workshop area; aisles and driveways must be installed. Of the sanitary devices, the most effective is local exhaust ventilation, which ensures the capture of harmful emissions at the point of their formation. A number of galvanic processes are carried out in baths without the need for local exhaust ventilation. These include: copper plating and galvanizing baths in an acidic electrolyte, chemical neutralization baths (soda), deca-citing, washing in hot and cold water, clarification. However, the vast majority of galvanic baths and other units for metal coating must be provided with shelters with exhaust ventilation or by onboard suction.
The amount of air removed by on-board suction and the minimum speed of air movement above the baths, depending on the nature of the process, are reflected in SN 245--71 and in special sanitary rules. Depending on the width of the baths, single-sided suction (width up to 700 mm), double-sided (width 700-2000 mm), single-sided with blowing (over 2000 mm) are used. To compensate for the air removed from the baths, a mechanical inflow is organized into the upper zone with uniform distribution throughout the room; the inflow velocity should be low (no more than 2 m/s). In this case, it is necessary to supply no more than 2000 cubic meters of air per hour for every 15 cubic meters of floor area of the main production room.
To prevent the release of harmful gases and vapors from the surface of the electrolyte, additives are used. Currently, a number of acid corrosion inhibitors are used for this purpose in galvanic and pickling baths.
Mechanization and automation of metal coating processes eliminates manual operations and eliminates contact with harmful substances. No less important is the replacement of toxic electrolytes and compounds with less toxic ones, if this is allowed by technology (for example, replacing zinc cyanide with ammonia, copper cyanide with ethylenediamine polyethylene polyamine, eliminating chromium).
To protect the skin from the effects of aggressive substances, galvanizing workers are provided with mittens, aprons, boots, moisture-proof and acid-resistant, and workers in other areas of metal coatings, if necessary, are provided with goggles and filtering gas masks. After work, it is necessary to lubricate the skin with indifferent ointments and creams. If workers' hypersensitivity to nickel or chromium is determined using skin tests or during medical examinations, they should be transferred to another job.
When working with cyanides and chromium compounds, special attention should be paid to the immediate treatment of micro- and macro-damage to the skin (antiseptic solution and adhesive patch).
Electroplating workers must be well instructed in safe work In the presence of electric current, they should be trained in first aid measures for electric shock and when electrolyte solution gets into the eyes. Workers and employees of mechanical engineering factories undergo preliminary and periodic medical examinations once every 24 months.
CONCLUSION
As can be seen from the above, in most areas of galvanic production, liquid, gaseous and dust aerosols are released into the air of the working area.
One of the most unfavorable factors of galvanic production is pollution of the external air on the territory of the enterprise and internal premises with metal compounds and various toxic fumes, as well as acid emissions.
In order to avoid unpleasant emergency situations, it is necessary to inspect work equipment, gas lines, acid lines, air ducts of safety systems and other equipment in advance. Carry out scheduled preventive maintenance. Observe safety precautions and regulations at all times.
ANNEX 1
SAFETY REQUIREMENTS WHEN WORKING IN GALVANIC PRODUCTION
Everyone working in the electroplating workshop must comply with the following safety rules:
b perform only assigned work; work on serviceable equipment, using serviceable tools and devices;
b use the tool only for its intended purpose;
ь immediately report all malfunctions and dangers to others during work (lack of fences, uninsulated electrical wires and live parts of equipment, tools, etc.) to the foreman;
b do not lift weights in excess of the permissible norm (20 kg for women and 50 kg for men);
Do not store personal items in the work area, do not take food or water, and do not smoke.
Before starting work you should:
b wear work clothes (robe, apron, sleeves, rubber boots and gloves, safety glasses) depending on the nature of the work being performed;
b carefully inspect the workplace and put it in order: remove all unnecessary items; arrange the tools, devices, materials and parts necessary for work in a convenient and safe order, adhering to the principle: what is taken with the left hand should be on the left, and what is taken with the right hand should be on the right; prepare personal protective equipment and check their serviceability;
b check that the floor near the workplace is clean, dry, uncluttered, and that the movable grille is in good working order;
Turn on the ventilation.
During work you must:
ь monitor the serviceability of the equipment, prevent leakage of electrolytes;
b fill the baths with electrolytes only when the supply and exhaust ventilation is turned on under the supervision of a specialist;
b when preparing an electrolyte, add acid to cold water and in no case vice versa, as this can lead to the release of acid from the vessel; pour the acid into the water in a thin stream, stirring the solution thoroughly all the time (adding acid to heated water is not allowed);
b when preparing mixtures of acids, the latter should be poured with sulfuric acid;
b Spilled acids and alkalis must be immediately neutralized and cleaned up: concentrated acids are abundantly diluted with water, covered with chalk until completely neutralized, then the resulting salt is swept away and removed;
b Carrying bottles with acids is only allowed in exceptional cases and over close distances, while the bottles are carried by two people on special stretchers, it is prohibited to carry a bottle with acid on the back, shoulders or pressed to the chest;
b splashes of acidic electrolyte that get on open parts of the body must be washed off with a copious stream of water, and then with a 2% soda solution and again with water, splashes of chrome electrolyte with a 5% solution of hyposulfate, and electrolyte for oxidation with water; in all cases, if acid or alkali comes into contact with the body, it is necessary to immediately treat the affected area with water (within 10 minutes); fountains installed at workplaces should be used for eye washing;
It is necessary to remember that any preliminary wiping of skin areas doused with acid or alkali only aggravates the burn;
b in order to avoid parts falling into the bath with electrolyte, inspection, cleaning and securing them in a device above the surface of the bath is prohibited;
b When removing parts from the bath, it is necessary to wait for the electrolyte to drain into the bath;
b rods, suspensions and anodes should be cleaned only with a wet method, since non-ferrous metal dust is poisonous and inhaling it can cause poisoning;
b To remove parts from the bath, you should use special devices or tools - magnets, tongs, scoops;
b acids and alkalis stored in bottles, cans, cans or barrels in warehouses, workshops or factory sites must have tags or labels clearly indicating the name of the product; if the inscription is erased or tags and labels are missing, then they need to be restored; for this purpose, samples are taken and the products are analyzed in chemical laboratories; accidental injuries to the skin of the hands must be immediately protected with a waterproof bandage or contact a medical center;
Workwear contaminated with acids, alkalis and other chemicals should be immediately removed and washed.
After finishing the work you need:
Turn off the power to the baths, turn off the water and steam;
b clean the workplace, clean the hoses, remove the anodes from the bath and wash the drains and floor;
b remove parts, fixtures and tools to designated areas;
b remove protective clothing and protective equipment, clean and fold them;
Wash your hands and face with warm water and soap or take a shower.
BIBLIOGRAPHY
1. Electroplating. Reference publication. Azhogin F.F., Belenkiy M.A., Galyev Ch.V. and others. M. “Metallurgy”, 1987.
2. Handbook of electroplating. Kadaner A.I. 1976
3. Degreasing, etching and polishing of metals. Grilikhes S.Ya., M., VINTI Production and Publishing Plant.
4. Brief reference book Galvanotechnics. Yamnolsky A.M., Ilyin V.A., “Mechanical Engineering” 1981.
5. Protective coatings metals Liner V.I. M., “Metallurgy” 1974.
6. Basics of electroplating. Vyacheslavov P.M., “Lenizdat”, 1960.
7. Practical advice electroplating Lobanov S.A. "Mechanical Engineering" 1983.
8. Organization of galvanic production. Vinogradov S.S., M "Globus" 2005.
9. Electrolytic deposition precious metals, Burkat G.K., M, Technical Committee for Standardization TK 213, 1993.
10. Industrial sanitation and occupational hygiene. Uch. village for universities, Glebova E.V., M. Higher. school, 2005.
Today, hot-dip galvanizing is a priority for all hardware manufacturers. This popularity is due to reasonable prices for zinc, maximum protection against rust and deformation, and the long service life of galvanized products. When working in the workshop, you should follow safety rules - this method is not harmless to human health, there are also dangers of hot-dip galvanizing.
Features of the galvanizing process
Each stage of the hot-dip galvanizing procedure is accompanied by work with chemicals that have potential danger for the environment and for human body. Because of dangers of hot-dip galvanizing factories with workshops where metal processing is carried out are built far from populated areas. Many enterprises carry out preliminary preparation of metal products in special capsules that do not allow chemical fumes to pass out.
Safety precautions for employees
Shop workers must be attentive to any small details in production:
- check baths containing molten zinc for cracks;
- monitor the location of the metal structure to avoid injury from sharp corners;
- If you inhale zinc fumes, seek medical attention immediately.
Finished metal structures are not capable of causing harm to the environment and human health. Galvanized surfaces do not emit toxins. Typically, enterprises properly dispose of chemical waste, so hot galvanizing can only harm the workshop employees, but not the environment.
A galvanic shop is currently needed to apply a special coating to a metal product. This material itself is susceptible to corrosion, and its service life is not very long. That is why a method is used in which a thin layer of another metal is deposited on the surface of the raw material in an electrolyte solution and using an electric current. This is the main purpose of the galvanic workshop.
Equipment for work. Bath
These workshops have a variety of equipment, but the main one is a galvanic bath. This device is divided into two types. The first is called active, the second - auxiliary. They differ in that in the first types of baths the required coating is directly applied to the product. In the galvanic workshop, the stage of preparing the part for the further procedure takes place. The important thing to understand here is that auxiliary equipment is just as important as the main one. Among them are baths for washing, drying, and preparing the mixture.
Bathtub design
The design of the baths in the galvanizing shop is quite simple and is a cube that has additional stiffeners, as well as some additional elements. Among such additional devices, for example, there is a heating element, a lid, filtration, a cooling system, a water supply and drainage system, cleaning systems, suspensions, anodes, etc.
For the production of such things, stainless steel, PVC, polypropylene, as well as other raw materials with similar characteristics can be used. However, at present, PVC and polypropylene are the most widely used, and steel and metal products have faded into the background. This is due to the fact that polymer materials more resistant to exposure to aggressive chemicals and high temperatures.
Special purpose devices
Electroplating production requires special-purpose baths that are designed to work with small parts.
The first equipment of this type is a bell bath. The main difference between this type of device and the main one is that it has a special bell, and the main purpose is to apply galvanic coating to small parts in bulk form. The bell itself is truncated and has a multifaceted design. Such a device is used both as a stand-alone machine and in a line.
Electroplating production periodically requires equipment such as a galvanic drum. It is a prism, which is made of either PVC or polypropylene, which has many edges, all of which are perforated. To rotate such a prism, a motor with a gearbox is used, and torque is transmitted through a gear-type wheel system. The drum can be used in manual, automated and mechanized line types.
What is a line
A galvanic line is a set of several devices that operate in one area. The main parameters for the design of such systems are their performance, as well as the dimensions of the product for which this line should be designed. The type of line will directly depend on how large the dimensions of the product will be and what its serialization will be. Galvanic lines can be of the screw type, they can be manual or manual with a telpher. Today, the automatic operator type of line, which has software control, is becoming very popular.
The line may also include auxiliary equipment. It is necessary in order to withstand the technological process, as well as ensure complete safety of work for people on the site.
Types of auxiliary installations
Electroplating equipment used at sites must prepare raw materials and components for further work. For this purpose, for example, there are two filter units. One of them is stationary, the other is mobile.
If we talk about the first type of installation, then the UFE-1S model is usually used. It is intended for filtering either water or electrolyte from any mechanical impurities. An additional feature of the stationary type is that it can be connected to an airless mixing system, which has a solution filtration function.
A mobile type filter is usually represented by the UV 2400 model. It can be used, like a stationary one, to filter electrolyte or water from mechanical contaminants. Their difference is that this pump can also pump this water or other aggressive chemicals.
Liquid demineralization devices are also used. The unit is presented in the form of an UVD-500 installation, which is capable of removing salt from a liquid so that it fully complies with a state standard such as 6709-97. This water is used to prepare a new electrolyte, as well as for any washing operations carried out in the workshop.
There is also smaller equipment, for example, conventional pumps, but with increased resistance to chemicals in order to successfully pump electrolyte. Equipment is used for drying products.
Ventilation
Ventilation of a galvanizing shop is one of the most important occupational safety requirements. This is very important, since during the galvanic process, that is, the coating of products, harmful vapors are released into the air, which are dangerous not only for humans, but also for the room where they are released. Because of this, when designing a workshop, special attention is paid to ventilation equipment and ventilation in general.
For this type of workshop, it is allowed to use ventilation pipes made of polypropylene. This is because this material belongs to the non-flammable group, is moisture-proof, resistant to chemical influences, and is also very easy to install both on the ceiling, floor or walls.
Workshop safety
The harmfulness of the galvanic shop to human health is quite high. The thing is that there are several very dangerous factors. Firstly, there is the possibility of receiving a strong electric shock, secondly, there is a risk of getting chemical, alkaline or acid types of burns, and thirdly, there is a risk of explosion and fire.
However, the harm to human health does not end there. For example, when preparing a product, it is subjected to mechanical types of processing. This can be grinding, blast cleaning using mechanical dust and many others. All of them are united by the fact that during their implementation a huge amount of dust is released into the air. In addition, the noise and vibration levels exceed permissible limits. Since electric current is used during coating, the likelihood of injury from this same current greatly increases. For this reason it is most often used D.C. with a voltage of 12 V. However, there are some operations that require increasing the voltage to 120 V. For example, this occurs when it is necessary to oxidize aluminum.
Fire safety requirements for electroplating shops are also quite high. To prevent fire in such premises, it is necessary to apply fire protection that will comply with GOST 12.1.004-76. Explosion safety in such areas must be ensured using explosion prevention and explosion protection measures in accordance with GOST 12.1.010-76.
Liquid purification
It is worth saying that in galvanic shops there must be facilities for purifying the liquid that was used in the work. This is very important, since during the technological process water is mixed with acids, alkalis and heavy metals. Conventional water purification installations are unable to cope with the removal of such contaminants, and therefore, when designing a building, it is necessary to initially allocate space for special installations.
Chromic anhydride
From a technical point of view, it is a combination of two substances such as chromium and oxygen. It is very often used in the chemical industry, and therefore is often called chemical acid. This substance dissolves quite well in water, which is excellent for use in workshops where most operations are carried out with liquid content to one degree or another. Chromic anhydride is currently most widely used in three areas: mechanical engineering, metallurgy, chemical and petrochemical industries. Depending on its purpose, this substance is produced in three categories: A, B and C.
- Grade A is used in cases where, under production conditions, it is necessary to obtain metallic chromium or other materials, but with sufficiently high hardness values.
- Grade B is used for the production of electrolytic chromium and in the production of catalysts. It is this anhydride that is used in electroplating shops.
- As for grade B, it is most suitable for raw material foundry operations.
Generally speaking, this type of workshop is extremely necessary, but at the same time quite harmful and dangerous. Because of this, all safety requirements must be met and the best ventilation must be installed.
In modern industry, Soviet atavism is still alive - the consumer attitude towards natural resources. This is noticeable even at the stage of training engineers and workers. Unfortunately, it is believed that the capacity of nature is limitless, that it is capable of absorbing all the dirt and waste products of production, accumulating it within itself and forever sealing it in its depths. A kind of unlimited toilet. But the reality is that sooner or later, this toilet gets clogged and everything comes out. This happens either explicitly - man-made accidents, emissions, or implicitly - the poisoning of waste into the environmental medium: water, soil, air, from where everything eventually enters the body of unsuspecting people. And galvanic production, for the most part, has the second type of effect. How many people even know about it? How many people know about the harm that electroplating waste causes to their health? But these pollution are in FIRST place, surpassing oil spills and radiation!
This section will provide an educational program on the issue of ecology of galvanic production. This is especially true in the Urals - electroplating in one form or another is present at all our factories, and engraving is generally impossible without electroplating. The problem is that most enterprises have neither treatment facilities nor waste-free production technology. And the main pollutants are heavy metal ions - IHM. Let's remember the school chemistry course...
ITM. Heavy metal ions are zinc, nickel, chromium, copper, tin, lead... and a good part of the entire periodic table. And they merge because sooner or later the coating electrolytes fail, and their volumes and replacement frequency are significant. Of course, it’s easier to pour everything into the nearest reservoir or bury it in the forest if we are talking about 50 liters or 10 kg per year. But what if it’s tens of cubic meters per week or tons per month? How aware are we of this (we should mention here our right to know the extent of the harm and receive compensation for it)? As a result, we have hundreds of tons of toxic waste. How are they harmful? Most ITMs are carcinogenic - meaning they cause cancer. They accumulate in the body and leave it very slowly. Chromium, for example, can be absorbed even through the skin and exhibits carcinogenic effects in extremely low concentrations. Here we note that the most harmful is hexavalent chromium - the main component of chromium plating electrolytes, as well as zinc passivation.
But the harm of ITM is not limited to this. They also have an allergenic, teratogenic, and general toxic effect, which consists mainly of blocking enzymes and hormones and disrupting regulation in the body, as well as metabolic disorders. To be fair, let’s say that probably only gold and a small number of other chemical elements have a function that is unclear to science in the human body. Other elements, including metals, play important roles. They are divided into macro, micro, ultramicroelements and are contained in the body in sizes from kilograms to micrograms. Harm from them occurs when they enter the body one-time or systemically in quantities exceeding physiologically acceptable ones. To control these quantities, standards for maximum permissible concentrations of chemical compounds - MAC - were invented. Without going into the intricacies of dividing MPCs into categories, let’s say that in Russia they are among the most stringent. But this does not mean that they are always fulfilled. Since the fines for violating them are unfairly small, and the methods for establishing an environmental crime are extremely imperfect and ineffective. Especially in light of the latest innovations of our government. There is just one fact - there is no environmental police in Russia. Who will investigate environmental crimes?
Ways of ITM entering the human body. On the issue of waste treatment. Until now, the most common method of recycling galvanic waste is the reagent method. Its essence is that all waste is converted into a solid, slightly soluble state by treatment with special reagents. Then tons of such waste are buried in special landfills. There are not enough such landfills in the Urals. And it’s quite logical to ask, where does the waste go? Even many directors of enterprises where this waste is generated do not know the answer to this question. And dislocating them in public landfills is perhaps the best thing to do with them. But even if the waste is buried correctly, this does not mean that it is neutralized. Thus, although buried compounds (mainly hydroxides) are poorly soluble, a certain part of them still comes with rain, melted, groundwater into drinking water sources, and from there into our bodies. Or these compounds accumulate in the plants that livestock eat or in the water they drink. Then ITMs accumulate in meat, milk, and animal fat and happily arrive at our table, continuing their expansion. As mentioned earlier, the human body leaves ITM with great reluctance.
There are numerous alternative developments, but they all have two things in common - the huge cost of equipment, technology and Supplies and the fact of the transfer of pollution from one area of production to another. A simple example is membrane cleaning technology. In such an installation, the main consumable element is the membrane. But where will she go after serving her sentence? It turns out that now we have to come up with a facility for processing used membranes. And then a plant for processing what remains after processing the membranes, etc.
It is necessary to use resources 100%, that is, to bring the technology to such a level that from all the “tails” commercial products are obtained, which can then be used either within the enterprise or sold to the external market. And it's possible!
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