Ministry of Higher and Secondary Special Education of the Republic of Uzbekistan
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ВКР. Ашурова О.Э.
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Preparation of solutions and dehydration. Technical zinc sulfate is produced by evaporating a solution of zinc sulfate in a fluidized bed furnace (BL). The solution after cementitious purifications from cadmium in the cadmium production is fed to the filter press for filtering. The filtered solution is sent to a filler with a capacity of 70 m3. From the collection container, the gravity solution is periodically poured periodically as necessary into a 20 m3 supply tank. The tank is equipped with a level gauge for measuring the amount of solution. From the supply tank, the olution is pumped to the nozzles and sprayed into the furnace. Dehydration. The jet of sprayed solution from the nozzles is directed into a fluidized bed consisting of granular zinc sulfate. The temperature in the fluidized bed is maintained within 240-2900 C due to the heat of the gases generated from the combustion of natural gas in the furnace. The temperature under the hearth of the furnace 780-8600 C is regulated by the amount of natural gas supplied. To remove gases and water vapor, a vacuum of 5-10 mm water is maintained in the furnace. the column, which is created by a smoke exhauster installed at the end of the gas duct. The gases leaving the furnace are cleaned of dust in the SIOT cyclones and the TsN-15 group cyclones connected in parallel with them. Dust from cyclones through airlock locks is discharged into the hopper. The purified gases are emitted into the atmosphere through the chimney. The fluidized bed on the bottom of the furnace is created by ensuring the elasticity of the blast under the bottom of the furnace within 800-1000 mm of water column created by the supercharger. The total air flow in this case is 10000-12500 m3 / h. The height of the layer is regulated by gates on the estrus drainage estrus within 500-700 mm. Granulated sulphate from the furnace through the drain threshold is continuously unloaded into the hopper from where it is packed into specialized containers or paper bags for. Start of the BL furnace. The start of the furnace begins with checking the technical condition of the furnace, the presence of the initial solution, testing all the mechanisms in operation. The sequence of operations for starting the furnace: - the furnace is sealed; - the smoke exhauster is included in the operation and a vacuum is created in the furnace 5-8 mm water column; - the supercharger is put into operation according to the instructions; - a gas burner is ignited while supplying primary air. Ignition of a gas burner is carried out in accordance with the operating instructions for the furnace of the furnace to "BL". - the furnace is heated to a temperature of 600-6500 C; - secondary air is supplied to create blast elasticity under the hearth, while the air flow is brought up to 6000-9000 m3 / h; - the temperature under the hearth rises to 780-8000 C; - a layer is loaded, granular zinc sulfate with a granule size of 3-4 mm in an amount of 2-3 tons is used as a material; - air consumption increases until the blast elasticity is established under the hearth 800-900 mm and amounts to 10000-12500 m3 / h; -the temperature in the layer rises to 190-2600 C; - the pump for supplying the solution to the nozzles starts up. The flow rate is regulated by valves installed on the solution supply line, the hydrodynamic and temperature conditions of the furnace are established. The furnace productivity is regulated by the amount of solution supplied to the furnace and the temperature in the furnace layer, discharge of granules from the furnace and dust collected in cyclones is organized. Further work is reduced to maintaining the established technological regime and servicing the units of the installation. Stopping the furnace. The procedure for stopping the furnace: - the flow of solution to the nozzles and gas to the burner stops; - nozzles are taken out of the furnace; - air supply to the furnace continues until the layer is completely unloaded through the threshold; - the supercharger and the exhaust fan turn off. Process control. The control of the technological process is carried out by the maintenance personnel of the workshop directly at workplaces using measuring instruments. Samples of aqueous solutions are taken by maintenance shift staff and analyzed in an express laboratory. The quality control of zinc sulfate is carried out by the controllers of the Technical Control Service (STK) according to the results of chemical analyzes of the Central Expert Analytical Laboratory (CEAL) in accordance with the chemical control map. Determination of harmful impurities in the air at workplaces, control of technological dust and gas emissions is carried out by the department for research and environmental protection of the plant CEAL according to the schedule. Conditions for safe conduct of the process. A particularly dangerous section in the department is the furnace of the BL furnace for burning natural gas. A fired or operating unit must be immediately disconnected from the distribution gas pipeline in the following cases: - violation of the density of flange and other connections, breakdown of gas pipelines, shutoff valves of burners; - cessation of air supply to the burners; - a sharp fluctuation in gas pressure at hydraulic fracturing; - stop the smoke exhaust and stop the traction from the unit; - explosion of a gas-air mixture in the Conditions for safe conduct of the process. A particularly dangerous section in the department is the furnace of the BL furnace for burning natural gas. A fired or operating unit must be immediately disconnected from the distribution gas pipeline in the following cases: - violation of the density of flange and other connections, breakdown of gas pipelines, shutoff valves of burners; - cessation of air supply to the burners; - a sharp fluctuation in gas pressure at hydraulic fracturing; - stop the smoke exhaust and stop the traction from the unit; - explosion of a gas-air mixture in the furnace space or gas duct; - fire in the immediate vicinity of the gas duct; - destruction of the masonry furnace. It is necessary to constantly monitor compliance with the gauge mode in the furnace and gas ducts. The main hazard in the compartment is zinc sulfate dust. Sealing equipment, local aspiration and general ventilation prevents the release of harmful substances into the atmosphere of the workshop. As personal protective equipment are used: respirators, goggles, protective clothing, safety shoes, and a helmet. Description of marketable products. The products manufactured by the department are technical zinc sulfate. Technical zinc sulfate is a granule, powder or a mixture of white color. It is used as a reagent in the enrichment of non-ferrous metal ores at concentration plants and for other purposes. Fire and explosion safe. Packed in double plastic bags, packing weight 50 ± 2 kg. It is transported under conditions that protect zinc sulfate from moisture. Supply of fuel and energy resources. 1. Natural gas supply. Natural gas enters the zinc sulfate production department from the medium-pressure factory line through a gas pipeline with a diameter of 80 mm and a pressure of not more than 3 kgf / cm2. Supply of fuel and energy resources. 1. Natural gas supply. Natural gas enters the zinc sulfate production department from the medium-pressure factory line through a gas pipeline with a diameter of 80 mm and a pressure of not more than 3 kgf / cm2. Gas is supplied to a gas distribution point (hydraulic fracturing station) installed at 4.8 m. Natural gas from hydraulic fracturing with a pressure of 0.3-0.5 kgc / cm2 is fed into the burner of the furnace of the BL furnace. 2. Supply of electricity, industrial water. The department for the production of anhydrous zinc sulfate is part of the cadmium workshop and is located in this building. Schemes of their supply and description are given in the technological instructions for the production of cadmium. Technological computation. Colculation of zinc smelting equipment to obtain zinc sulphate. Melting of zinc in the equipment is carried out in the following equation. Melting of zinc in the equipment is carried out in the following equation ∑. Zn+0.5O2+H2SO4→ ZnSO4·5H2O Output data Sanded Zinc kg/sum ………… ……....7564 The amount of sanded water ……… …….5 Compounds that come with sands in a mechanical oven ……30 The main compositions of mixture that comes in the mixture is as follows ZnSO4·5H2O ………..12862 H2SO4 ……………..2365 H2O ……………38839 Total:
2. The pressure of saturated water vapor coming into the injector. 3.Burning Zn with waste. 4. Ignite ZnSO4·5H2O in the aqueous phase %. 5. Concentration of solution discharged from equipment. 6. ZnSO4·5H2O 7. H2SO4 8. Relative humidity 9. The temperature of all substances. Raw material account Basically with the tower 12862 ZnSO4·5H2O, also H2SO4 2365kg and water volume 3883 tons 54066 kg basis. Contains the liquid coming out of the tower: 29578+12862=42440 kg In the amount of fluid in the diur: 88418·0.0277=244kg H2SO4 In addition to 30 kg sandstone and 88488-(42440-2449+30)= 43499 kg H2O 2449 kg H2SO4 comes out of the tower, and 2365 kg of H2SO4 Is given to the base 2449-2365=84 kg H2SO4 should be given with sulfur oil. Sulfuric acid supplied with total sulfur oil 11619+84=11703 kg The fluids lost in ZnSO4·5H2O formed in the tower are proportional. 29578·0.005=148kg With this amount ZnSO4·5H2 is lost 88418·148/42440=308kg Fluid as will give 308·0.0277=9 kg H2SO4 To crystallization 308=15 kg H2O 88418-308= 88110 kg fluid 30 kg extra and 434999-151=43348 kg Tower equipment Sulfuric acid is given the infusion of sulfur oil. Therefore12703 kg of H2SO4 should be given 11703/0.928=12652 kg of sulfur oil. 12652-11703= 949 kg The tower is supplied with O2 injectors, which increase their productivity in the form of 250 m3/s oxygen air at a consumption of 150 kg/s and a vapor pressure of 3·105 4/kg 250*24*4=24000 m3 According to the mass of air and pipe air 24000/0.861=27873 kg/per day There is 0.861 m3/kg of dry air to 1 kg of wet air This amount contains 278*75*0.01042=290 kg og water and 6467 kg oxygen. Steam coming from the injector 150*24-4=14400 kg. The theoretical basis of the firing process During firing, mainly the process of oxidation of sulfides. The oxidation mechanism includes the following stages: 1. Adsorption of molecular oxygen on the surface of sulfides and its dissociation into atomic oxygen; 2. Diffusion of oxygen into the sulfide lattice and counter diffusion of sulfur to the interface; 3. The formation of primary compounds of sulfide with atomic oxygen; 4. Chemical interaction of the resulting intermediate product with the sulfide remaining in the center of the grain and the burning of the sulfides of the material by the release of sulfur oxide and dioxide; 5. Chemical interactions of oxide of the surface of the film with sulfur dioxide and the formation of secondary sulfate. Firing is carried out in one stage. The concentrate is continuously loaded into the working zone of the BL furnace, and the product is removed by gravity from the furnace. The fluidized bed is characterized by a constant temperature at all points (940–980 ° C) and intense heat transfer. The main heat (about 70%) is generated from the combustion of sulfide materials. This heat is removed using special apparatuses. The material in BL is fluid, intensively mixed, which ensures uniformity of the layer in composition and temperature. Technology selection and justification Technical and economic indicators of firing depend on the raw material, the device of the furnace and the mode of its operation. Before firing, as a rule, a charge is prepared. At zinc plants, a mixture of concentrates that differ in composition is usually processed. When batching, concentrates are mixed in proportions, a certain composition of the mixture of zinc, associated with useful and harmful components. The composition of the mixture must satisfy the conditions ensuring the achievement of the goals of firing. The mixture is fed to the BL furnace in dry form or in the form of pulp. A pulp charge is preferable when the zinc plant is near the concentrator, which supplies the plant with concentrate, or when very different concentrates go into the charge (in the state of the pulp, the mixture mixes better and faster). processing, enhances corrosion of equipment and exhaust systems. The pulp is more difficult to evenly distribute over the fluidized bed. To quickly distribute the mixture over the fluidized bed, for more un-moistened exhaust gases, to facilitate their processing, we will take the mixture with a moisture content of 8%. Before firing for more complete firing and a high degree of desulfurization, we average the material. Ecology and labor protection. The rapid development of electronic technology in the human world has led to great changes in human life.There was food, clothing, home heating, a variety of vehicles, a change in the environment.The release of carbon monoxide, sulfur oxides, nitrogen oxides, fluorine industrial dust and moisture into the atmosphere from the development of especially heavy industry - mining, metallurgy, chemical light industry - causes environmental problems.For example, 70% of atmospheric transport, 250 million tons of dust, 200 million tons of carbon monoxide, 150 million tons of sulfur oxides per year. Annually, 25% of industrial waste is iron, 80-90% of mercury and lead. metal compounds are absorbed by plants and pose a threat to living organisms. Including the effects of the noise around us on the human body causes 85-90 getsbl high neurological diseases. Gaseous, liquid and solid phase wastes from the chemical industry should be neutralized. Methods of cleaning the environment. We physically and chemically divide industrial waste treatment into four stages. 1. Absorption method - purification of liquid mixtures by washing. 2. Adsorption - washing of gas and dust wastes. 3. Chemisorption - washing of waste with chemically bound reagents. 4. Kabolitin method is the neutralization of the mixture from the gases by heat. In these methods, industrial wastes are neutralized at high yields, leading to the synthesis of recycled chemicals. A scrubber is used to wash the technical exhaust gases. In particular, by absorbing toxic gases using liquid reagents, a new compound with CO2, H2S is washed with a 3% solution of Na2CO3 with Cu(NH4)2. 2. In turn, the waste and dust are cleaned by passing solid solvents activated charcoal silica gel, zeolites, iron hydroxide, active equipment. Since the industrial waste cannot be reused, the thermal method is decomposed using 800-1000 ° C oxygen. Katashtia method - neutralizes and purifies toxic wastes using a catalyst (CuO, mno, platinum, palladium salts). At present, nuclear power plants use nuclear power plants to generate electricity.In the Hiroshima tragedy in Japan, an atomic bomb contained 740 grams of radioactive material. When the Chernobyl nuclear power plant crashed, the presence of 63 kg of radioactive material caused great damage to the environment, living organisms and flora. The use of nuclear power plants has environmental advantages. 1. No emitted gas is released into the atmosphere. 2. The use of 0.5 kg of radioactive material as fuel for the reactor is equivalent to 100 million tons of coal. 3. . When the operation of NPPs is under strict control. Occupational safety. On the basis of guidelines such as safety rules in the extraction of acids and alkalis, workers are subjected to safety tests. In the production of zinc sulfate, labor protection of equipment, apparatus, technical items related to the shop building must ensure safety with: 1. . Zinc sulfate affects the respiratory tract, skin and gastrointestinal tract of living organisms in the form of aerosol vapors. Workshops will be provided with special overalls, shoes, gloves and safety glasses. 2. The danger zone in the shop is the "ks" furnace, because the combustion of natural gas and fuel oil can lead to explosions, fires. Therefore, the pressure gauge must strictly control the gas flow. Accidents, accumulation of carbon monoxide and sulfur dust, etc. can occur as a result of misconduct by maintenance workers during work. Conclusions Today it plays an important role in the development of ferrous and nonferrous metallurgy, chemical products, machinery, electronics, automotive, aircraft, oil and gas, light industry, etc. Non-ferrous metals: copper, gold, silver, osmium, indium, molybdenum, zinc, lead, etc. are mined and processed. Zinc metal is formed from sulfides into sulfates, mineral fertilizers for industrial and agricultural plants, pesticides. Zinc sulphate is used in the metallurgical industry to enrich ores. Zinc sulphate is obtained by heating the zinc sulfide in an oven and selectively dissolving the sulphate compound in the boiling layer. In the metallurgical industry, the method of enrichment based on the property of which the properties of the minerals to be separated from each other differs greatly from each other. However, in order to obtain pure zinc by pyrometallurgical method, the amount of zinc in the raw material should not be less than 16%. Graduation thesis on “Methods and calculation of zinc sulfate”. Zinc and its compounds are introduced in several ways in the production of zinc sulfate. Technical zinc sulfate is produced by evaporating a solution of zinc sulfate in a fluidized bed furnace (BL). The solution after cementitious purifications from cadmium in the cadmium production is fed to the filter press for filtering. The filtered solution is sent to a filler with a capacity of 70 m3. From the collection container, the gravity solution is periodically poured periodically as necessary into a 20 m3 supply tank. The tank is equipped with a level gauge for measuring the amount of solution. From the supply tank, the olution is pumped to the nozzles and sprayed into the furnace. The jet of sprayed solution from the nozzles is directed into a fluidized bed consisting of granular zinc sulfate. The temperature in the fluidized bed is maintained within 240-2900 C due to the heat of the gases generated from the combustion of natural gas in the furnace. The temperature under the hearth of the furnace 780-8600 C is regulated by the amount of natural gas supplied. To remove gases and water vapor, a vacuum of 5-10 mm water is maintained in the furnace. the column, which is created by a smoke exhauster installed at the end of the gas duct.. Dust from cyclones through airlock locks is discharged into the hopper. The purified gases are emitted into the atmosphere through the chimney. The fluidized bed on the bottom of the furnace is created by ensuring the elasticity of the blast under the bottom of the furnace within 800-1000 mm of water column created by the supercharger. The total air flow in this case is 10000-12500 m3 / h. The height of the layer is regulated by gates on the estrus drainage estrus within 500-700 mm. Granulated sulphate from the furnace through the drain threshold is continuously unloaded into the hopper from where it is packed into specialized containers or paper bags for. Total:
1.The concentration of H2SO4 sulphate given for mixing 2. The pressure of saturated water vapor coming into the injector. 3.Burning Zn with waste. 4. Ignite ZnSO4·5H2O in the aqueous phase %. 5. Concentration of solution discharged from equipment. 6. ZnSO4·5H2O 7. H2SO4 8. Relative humidity 9. The temperature of all substances. Bibliography. V.Ya. Zaitsev, E.V. Margulis "Metallurgy of lead and zinc." Textbook for high schools-M .: Metallurgy, 1986, 263p. Yu.N. Matveev, V. S. Strizhko “Technology of metallurgical production”. Textbook for high schools.- M.: Metallurgy, 1986, 368p. N.N. Sevryukov, B. A. Kuzmin, E. V. Chelishchev “General Metallurgy”, Moscow: Metallurgy, 1976, 568 pp. S. S. Naboichenko, A. P. Ageev, A. P. Doroshkevich and others. “Processes and apparatuses of non-ferrous metallurgy”. Textbook for high schools. - Yekaterinburg: USTU, 1997, 648p. A.P. Snurnikov "Zn-ka hydrometallurgy" 1982, 190p. NP Diev, IP Hoffman “Metallurgy of lead and zinc”. Textbook for high schools. - Metallurgy, 1961, 390p. N. Dobrev Combine of non-ferrous metals: stages of development of “Non-ferrous metals”. 2001 Number 12. V.V. Geykhman, P.A. Kozlov, O.I.Reshetov et al. Firing of zinc concentrates with a distributed oxygen supply. "Non-ferrous metals." 2000 Number 5. VVGeykhman, P.A. Kozlov, V.A. Lukyanchikov Improving the purification of gases from roasting of zinc concentrates. "Non-ferrous metals." 2000 Number 5. A.A.Kolmakov, L.G. Sadilova, O.V. Sector "Calculations of technological processes in the metallurgy of lead and zinc": a training manual / KGATsMiZ.- Krasnoyarsk 1998, 120p. V.S.Kokorin "Hardware and technological schemes for the design of production of heavy non-ferrous metals": guidelines for course and diploma design / KGATSMiZ.- Krasnoyarsk 1983, 47p
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