Method for removing arsenic from cobalt production waste

FIELD: metallurgy.

SUBSTANCE: method involves solid-phase roasting of wastes mixed with soda to fix arsenic to a water-soluble form of sodium arsenate. Then, water leaching and deposition from arsenic solution is performed. In order to obtained the product from water leaching with low residual arsenic content of 0.7%, solid-phase roasting is performed at 850C so that a roasted product containing 2.9% of arsenic is obtained. Water leaching of the roasted product is performed with extraction degree of 84%. Deposition from arsenic solution is performed in the form of arsenic sulphide with sodium sulphide at pH=3 with deposition degree of 99.6%, and filtrate with arsenic content of 0.02 g/l for removal of residual amount of arsenic by neutralisation and deposition with iron compounds meets the requirements of sanitary norms.

EFFECT: obtaining low-toxicity commodity product of arsenic sulphide and product of water leaching with low residual content of arsenic.

1 dwg, 1 tbl, 5 ex

 

The invention relates to ferrous metallurgy, in particular to methods for removal of arsenic from waste cobalt production. The proposed method for the removal of arsenic from waste cobalt production includes solid-phase firing of waste in a mixture with baking soda, followed by water leaching the product of annealing and deposition from a solution of sulphide of arsenic. The method allows to obtain low-toxic commercial product of sulphide of arsenic, and the product from water leaching with low residual arsenic.

There is a method of sulfatirovnie lead-EAF dust grey at 325-350C for 120 min with subsequent leaching of the product sulfatirovnie solution of sodium sulfide and precipitation from solution in the form of sulphides of arsenic (A.S. No. 990841 the USSR. Method of removing arsenic from lead-EAF dust / Isabaev S.M., Zhumashev K., Mielke EG, Kasybekov X. BI, No. 3, 1983). Removing arsenic in the solution is to 98.6%. The disadvantage is the use of toxic and expensive sodium sulfide leaching the product of firing.

Known sulfate-sodium way of processing of arsenic-bearing dusts of lead plants, the method of melting copper slurries mixed with carbon and baking soda in a reverberatory furnace, and the lead-up to 90% passed in the metallic phase, and arsenic was concentrated in soda slags (Ponomareva E. the., Solovyev V.D., Bobrov V.V. Arsenic in lead-zinc and copper industries // Complex usage of mineral raw materials. 1978, No. 1. P.66-71). The sodium sulphate method consists in electroplate dusts with sodium sulfate and a reducing agent at a temperature of 1000-1500C in aqueous dissolution products of fusion, in which the arsenic goes into solution, from which is extracted is isomorphic to the coprecipitation of arsenate and phosphate. FI Loskutova with the staff of the technology of processing spaz, including firing in the presence of sulfur and subsequent water leaching SPECA for the extraction of arsenic as sodium arsenate with further transfer it into calcium arsenate. The disadvantage of these methods is highly toxic arsenic in the form of arsenate calcium and high temperature heat treatment.

The closest analogue of the present invention to the technical essence is a method of removing arsenic from a copper-lead spaz by roasting it with soda and subsequent leaching of the calcine hot water and precipitation from a solution of calcium arsenate (Sadilova L.G., Loskutova F.M. Processing spaz lead production/non-ferrous metallurgy. Izvestiya vuzov. - 1958, No. 5. .38-49). The sample of spaz consists of arsenides of copper, iron, lead, copper sulfides and iron. The analyte was heated to F. horovoy boat with air supplied to the furnace. Set optimum firing temperature of 650C, duration 4 hours, the consumption of soda 1 weight part per 1 weight part of spaz. During subsequent processing of cinder hot water removing most of 97.8% of arsenic was obtained at 70C, duration of leaching 30 min, G:T=5:1. The disadvantage of this method is highly toxic arsenic in the form of arsenate of calcium.

The technical result of the invention is the extraction of arsenic in non-toxic commercial product sulphide of arsenic and receiving product from water leaching with low residual arsenic. Technical result is achieved by the proposed combined method, which includes 3 main stages: solid-phase firing of waste in the mixture with soda; water leaching the product of the calcination of sodium arsenate and precipitation of arsenic from solution in the form of sulphide of arsenic (figure 1). For solid-phase firing does not require special equipment, you have the option of lowering the firing temperature of up to 800-850C. the Advantage of the proposed method is simple instrumentation process water leaching the product of annealing and deposition of sulphide of arsenic.

For solid-phase firing of waste in the mixture with soda is the translation of arsenic in the waste in a stable soluble form of arsenate magnesium in water-soluble form of arsenate on the Tory reaction

Mg3(AsO4)2+3Na2CO3=2Na3AsO4+3MgO+3CO2.

Solid-phase sintering waste was conducted with the following parameters: the ratio of the charge waste/ash/coal=1:1:0,1; a temperature of 850C. the firing time is 3 hours. For solid-phase firing arsenic binds soda to form sodium arsenate. Burnt waste, the resulting solid-phase firing and used for further research, contained an average of 2.64-2,96% arsenic. X-ray analysis established that the mineralogical composition of the product of firing presents orthoclase (23,27%), carborundum (26,32%), magnesite (3,83%), goethite (3,32%), dolomite (3,26%).

The dissolution in water of the product of the calcination of sodium arsenate was carried out using factorial experiment, resulting in optimum conditions for water leaching temperature 70C, the ratio of T:W=1:7, the leaching time 30 minutes While the degree of extraction of arsenic in the solution averaged 80%. The product water from the leaching concentration of arsenic averaged 0.9 percent.

Example 1. Components included in the composition of the mixture: waste, caustic soda, coal was ground to a powder, separately, were weighed in a ratio of 1:1:0,1 (110 g waste, 110 g of sodium, 11 g coal) and thoroughly mixed. For firing were selected batch weighing 231, the Firing of the charge p is ofodile in a laboratory muffle furnace. At the optimum firing conditions: a temperature of 850C, duration of firing 3 hours from charge total weight of 231 g of the product of firing a weight of 148 grams and arsenic content of 2.9%, used for research of process water leaching.

For the research process water leaching using factorial experiment in a glass round bottom flask filled with water to a certain volume, for example 350 ml. Flask with water was placed in a thermostat heated to a predetermined temperature of 70C. When the desired temperature in the flask with water loaded with 50 g of the product of firing with arsenic content of 2.9%. Leaching was carried out with constant stirring for 30 minutes the Slurry was filtered on a glass funnel, the precipitate was twice washed with hot water, dried. The mass of the dried product after water leaching was 29 g with arsenic content of 0.98%. The degree of extraction of arsenic in the solution averaged 80%.

Example 2. Under optimum conditions of firing charge total weight of 525 g ratio waste/ash/coal 1:1:0,1 (250 g waste, 250 g of sodium, 25 g coal), a temperature of 850C, duration of firing 3 hours and the resulting product of firing a weight of 350 g and arsenic content of 2.9%.

For the process water leaching in a glass round bottom flask filled with water 1 liter, water is heated to a temperature of 75C, PR is the achievement of which is loaded with 200 g of the product of firing with arsenic content of 2.9%. The ratio of T:W=1:5. Leaching was carried out with constant stirring for 1 hour. The slurry was filtered on a glass funnel, the precipitate was twice washed with hot water, dried. The mass of the dried product after water leaching amounted to 129 g with arsenic content of 0.98%. The degree of extraction of arsenic in solution was 78%.

Example 3. Under optimum conditions of firing charge total weight of 29.4 kg) ratio waste/ash/coal 1:1:0,1 (14 kg waste, 14 kg of soda, 1.4 kg of coal), the temperature of 850C, duration of firing 3 hours and the resulting product of roasting weighing 20 kg and arsenic content of 2.9%.

Process water leaching the product of the calcination was carried out also on the pilot plant for chemical processing of mineral and technogenic raw materials. In a reactor with a stirrer is filled with 80 l of water, water is heated to a temperature of 70C, load 20 kg of the product of firing with arsenic content of 2.9%. The ratio of T:W=1:4. Leaching is performed under stirring within 30 minutes After the end of the leach pulp is fused to filter on the suction filter under vacuum. Filtered arsenate-carbonate solution perelavlivaet from the receiver in cumulative capacity. The precipitate on the filter was washed heated in the reactor with water (2 times washing). The washing water from the receiver peredelivay is camping in the reactor leaching the next portion of the product of firing. Formed 13 kg of dried product from the aqueous leaching arsenic content of 0.7%. The degree of extraction of arsenic in solution was 84%.

From arsenate-carbonate solution arsenic sulphide of sodium in the acidic environment is translated into a sulphide of arsenic. As the acid reagent was used 30% solution of hydrochloric acid. Precipitation of arsenic sulfide occurs when the pH value is 3. By checking the completeness of the precipitation has an excess of 12% solution of sodium sulfide, which accounted for 70% of the stoichiometrically necessary quantity (SOC). Studied the effect of temperature on the degree of precipitation of arsenic from solution (table 1). The table shows that at a temperature of 50C is observed, the degree of deposition of 99.6%and a residual concentration of arsenic in the filtrate equal to 0.02 g/l After complete precipitation of arsenic from solution, the slurry was filtered, washed twice with hot water. The filtrate when heated it turns transparent, colorless. To remove residual amounts of arsenic, the filtrate is subjected to chemical treatment with compounds of iron (III) and brought up to sanitary standards for arsenic. The precipitate of sulphide of arsenic is washed with hot water, dried at room temperature or at 40C and is ready products. The precipitate of sulphide of arsenic is used as a biocide in the composition of thermoplastic paints on the I production of antifouling coatings hulls of marine vessels. The concentration of arsenic in the sediment sulfide arsenic amounted to 48%.

Example 4. Under optimum conditions of firing charge total weight of 6300 g ratio waste/ash/coal 1:1:0,1 (3000 g of waste, 3000 g of sodium, 300 g of coal), the temperature of 850C, duration of firing 3 hours and the resulting product of the firing weight of 4200 g and arsenic content of 2.9%.

For the process water leaching into the reactor with a stirrer is filled with 80 l of water, water is heated to a temperature of 70C, load 20 kg of the product of firing with arsenic content of 2.9%. The ratio of T:W=1:4. Leaching is performed with constant stirring for 30 minutes Produces 13 kg of dried product from the aqueous leaching arsenic content of 0.7%. The degree of extraction of arsenic in solution was 84%.

Arsenate-carbonate solution obtained in the reactor with the following parameters: the ratio of T:W=1:4 (20 kg of burned waste and 80 l of water), temperature 70C, time of leaching of 30 minutes is used to study the deposition process. The concentration of arsenic in the source arsenate-carbonate solution was 6.6 g/l To perform the deposition process of the sulphide of arsenic in glass dvuhgolosy flask filled with 200 ml arsenate-carbonate solution. When the temperature reached 50C in a flask with solution is added to 43 ml of sodium sulfide (12%), 78 ml of hydrochloric is acid (30%). When the pH value 3 is formed yellow precipitate of sulphide of arsenic. After complete precipitation of arsenic from solution, the slurry is filtered on a porcelain Buchner funnel under vacuum, the pulp passes through the suction filter under the pressure of atmospheric air. The volume of filtrate to 250 ml weight of the wet sediment 16, After drying the sludge amounted to 4, the arsenic Content in the filtrate was 0.02 g/L. of the Filtrate is purified of arsenic by precipitation with iron compounds to sanitary standards.

Example 5. The deposition process is carried out at a pilot plant for chemical processing of raw materials. In a reactor with a stirrer is filled with 35 l arsenate-carbonate solution, heating the solution to a temperature of 50C. Under stirring solution is added to 7.5 l of sodium sulfide (12%), 11 l hydrochloric acid (30%) to pH 3. Maintain the slurry at a temperature of 50C and stirring for 30 minutes After complete precipitation of arsenic from solution, the pulp is fused to filter on the suction filter under vacuum. The filtrate is separated, collected in a collection tank. The volume of filtrate is 45 liters of the Precipitate on the filter was washed twice with hot water. The weight of the wet sediment 4 kg After drying the precipitate weight 0.9 kg of the Filtrate is subjected to chemical treatment with iron compounds to remove residual amounts of arsenic and brought up to sanitary standards for arsenic.

Table 1
The effect of temperature on the degree of precipitation of arsenic from arsenate-carbonate solution
no experienceV solution ml(As) in solution, g/l(As) in the sediment sulfide of arsenic, %The degree of deposition %
Source arsenate-carbonate solution2006,6
1.(25C) Acidic filtrate2290,4132,0892,8
2. (25C) "-"2220,5033,32to 91.6
3. (50C)"-"2440,02348,629,6
4. (50C)--"2500,02831,4899,5
5. (70)"--"2500,4639,5291,5

Method of removing arsenic from waste cobalt production, including solid-phase firing of waste in the mixture with soda for binding of arsenic in water-soluble form of sodium arsenate, followed by water leaching and precipitation from a solution of arsenic, characterized in that for receiving product from the aqueous leaching with low residual arsenic content of 0.7%, solid-phase sintering is carried out at 850C To produce the product of firing, containing 2.9% of arsenic, water leaching of the product of firing lead with a degree of recovery of 84%, and arsenic are precipitated from solution in the form of arsenic sulfide-sodium sulfide at pH value of 3 with a degree of deposition 99,6%and the filtrate arsenic 0.02 g/l of removing residual amounts of arsenic by neutralization and precipitation of iron compounds lead up to sanitary standards.



 

Same patents:

FIELD: process engineering.

SUBSTANCE: invention relates to hydrometallurgy, particularly, to mineral stock dressing devices. Proposed plant comprises reactor, control board, HV transformer, and pulse generator with bank of capacitors. Reactor is composed of rectangular cross-section vertical tube to process dry or wet mineral stock. Shelves are arranged inside said reactor hinged at 45-60 degrees to reactor vertical axis. Said shelves double as grounded electrode. HV electrode is mounted outside the reactor, at hole cut in its wall. Note here that shelf bent edge stays opposite HV electrode head to rest, from inside, onto spring-loaded support to allow vibration of shelves by shock wave effects.

EFFECT: higher quality of raw stock.

2 cl, 2 dwg, 1 tbl

FIELD: metallurgy.

SUBSTANCE: extraction of non-ferrous metals is performed in plasma electric arc furnace of alternating current, which has a group of electrodes and contains a molten liquid copper bath coated with liquid slag. The method involves a melting-reducing stage consisting of the following operations: loading of metallurgical wastes onto the surface of liquid molten copper bath, melting of metallurgical wastes in liquid slag at the slag/bath copper boundary, reduction at least of non-ferrous metals to the oxidation degree, which is more than or is equal to zero, and intensive mixing of the liquid molten copper bath by blowing of inert gas, preferably nitrogen and (or) argon. Mixing is performed so that it can be possible to avoid the formation of a crust, expedite the reduction reaction and cause the transition of copper-soluble non-ferrous metals to the molten copper.

EFFECT: increasing the extraction of non-ferrous metals from wastes.

16 cl, 9 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: product includes solid and/or liquid organic substances, crushed solid metals and/or alloys and their compounds are used as inorganic substances, and substances containing water and/or lubricating-cooling liquid are used as wet substance. Mixture contains metals and/or alloys and their compounds in the form of crushed and fibrous fractions; besides, size of crushed fraction is not more than 0.5 of the fibre length of fibrous fraction. The product is pressed at the share of the crushed fraction, which does not exceed the value providing the interweaving of fibrous fraction so that a frame is formed, and is subject to further deformation with the pressing force exceeding the limit of plastic deformation of fibrous fraction. The product is used as a regulator of processes of solid-phase refining reactions with pyrolysis products of hydrocarbon substances at heating of the product without any air access.

EFFECT: invention allows obtaining high mechanical properties of the product, using high-energy potential of substances used for its manufacture and improving environmental friendliness of the process.

16 cl, 1 dwg, 8 tbl, 3 ex

FIELD: machine building.

SUBSTANCE: plant includes two units, the first one of which is a lamp sorting unit, and the second one is a unit of multistage exit gas cleaning system. The first unit includes a lamp sorting device consisting of a loading assembly, a pneumatic vibrating separator with a crusher and a cyclone, a crushed lamp glass collecting hopper, a lamp base receiving container and a fluorescent dye container. The second unit is made in the form of multistage exit gas cleaning system consisting of a sleeve filter, adsorbers, a gas blower with a compressor, which creates negative pressure in the plant of 5-8 kPa in the lamp loading zone and up to 19-23 kPa before gas blower. The plant is equipped with a series pulverised-coal and gas emission cleaning system consisting of a cyclone, sleeve filters, a working adsorber operating on activated coal, which allows reducing mercury content in exit gases to the level of less than 0.0001 mg/m3.

EFFECT: improving utilisation efficiency owing to excluding the probability of PC-air emissions to a production room and improving energy resource saving of metal scrap processing and gas cleaning.

2 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: method involves loading material into a metallurgical furnace, heating and holding for 0.5-1.0 hour. Before heating, fluorides of alkali-earth and/or alkali metals are added to the wastes in amount of 1-5%. Heating is carried out at temperature of 1100-1300C and the wastes are held at this temperature without or with limited access to air while feeding gaseous reaction products into a dry gas cleaning system. Phase separation of the electrolyte and carbon in form of a carbon residue is then carried out.

EFFECT: recycling wastes, extracting valuable components from wastes and returning said components into the technological process.

5 cl, 1 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: melting of metal radioactive waste (MRW) is performed in oxidising atmosphere with oxygen content of 8-10% in liquid oxidised metal bath at content of oxygen in metal of 0.020-0.035%. At that, in order to extract radionuclides from metals and to reliably fix them in slag, oxidised slag of low basicity is used, accumulated deactivated metal is drained from melting chamber, thus leaving 20-30% of all-weld deactivated metal in the chamber. Before the metal is drained, loading of MRW to the melting chamber is stopped for 5-12 minutes and the flow of supplied fuel and oxygen to fuel-oxygen burners is reduced by 2-3 times. Amount of drain metal and drain rate is controlled. After 70-80 % of metal is drained, MRW loading to the melting chamber is renewed and flow of supplied fuel and oxygen to fuel-and-oxygen burners is increased to initial level.

EFFECT: invention allows efficient MRW processing and provides the reduction of evaporation from MRW surface of volatile radionuclides during melting process; reduction of fouling of refractory lining with radioactive slag when metal is being drained from the chamber; excluding the possibility of formation of dioxins during MRW processing.

8 cl, 2 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: method involves oxidation of micro production wastes at temperature of 550-650C in air atmosphere for destruction of crystal latitude Nd2Fe14B so that Fe2O3, Nd2O3, Fe2B is formed and moisture and oil is removed. Then, anhydrous fluorides of rare-earth metals are obtained and their metallothermic reduction is performed for production of constant magnets. After oxidation from oxidated microwastes is completed, rare-earth metals are leached with nitric acid with concentration of 1-2 mol/l at temperature of 20-80C. Obtained nitrate solutions containing rare-earth metals and impurity elements are processed with solution of formic acid with extraction of formiates of rare-earth metals in the form of the deposit cleaned from impurity elements, which includes iron, aluminium, nickel, cobalt, copper and other transition metals.

EFFECT: regeneration of rare-earth metals from production wastes of magnets and obtaining raw material containing rare-earth metals for reutilisation in production of rare-earth constant magnets.

2 cl, 2 tbl, 7 ex

FIELD: metallurgy.

SUBSTANCE: method involves leaching of cadmium from raw material in solution of sodium ethylene diamine tetraacetate with its further extraction from solution and regeneration of ethylene diamine tetraacetate. Cadmium leaching is performed in two stages. The solution obtained at the first stage is supplied for extraction of cadmium, and residue of the first stage is supplied to the second cadmium leaching stage. The solution obtained at the second stage is used for leaching of cadmium from raw material at the first stage. Besides, leaching at the second stage is performed in presence of hydrogen peroxide at maintaining its concentration in the range of 10-15 g/dm3 during 2-2.5 hours.

EFFECT: increasing cadmium extraction degree.

2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: method involves dissolving wastes and subsequent electrolysis of the solution, and is characterised by that electrolysis is carried out on vibrating electrodes at current density of 0.2-0.5 A/cm2. The anode is made from anodised lead and electrolyte components are in the following ratio: 40-60 g/l sodium chloride per 20-30 g/l copper-containing ammoniate wastes. The invention enables to obtain copper powder with particle size of not more than 300 nm, oxygen content of not more than 5% and output higher than 0.031 kg/(m2h).

EFFECT: high resistance of the copper powder to hydrogen wear in powdered compositions, high corrosion resistance of the powder, high efficiency of recycling copper-containing ammonia wastes.

2 dwg

FIELD: metallurgy.

SUBSTANCE: method includes joint leaching and activation of raw materials in a cage mill with extraction of metals into a solution simultaneously with crystal damage. After leaching and activation in a cage mill the material is laid into stacks, piles or trenches, treated with a solution of sulphuric acid. After treatment with a solution of sulphuric acid the material is washed with water, afterwards leaching is carried out with solutions of reagents. At the same time treatment of the material in stacks, piles or trenches is carried out with a solution of sulphuric acid with concentration of 10-30 g/l. Leaching of the material in stacks, piles or trenches is carried out with a solution of a sodium sulfide trioxosulfate with concentration of 10-20 g/l.

EFFECT: higher efficiency of metals extraction from mill tailings due to additional chemical treatment of mechanically chemically activated structural components of extracted materials after their extraction in a cage mill.

3 cl, 4 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method involves crushing of raw material, its heaping in the form of a pile, pre-treatment of raw material in the pile, treatment of the pile with a leaching solution, dilution of metals and obtaining of productive solution with removal of metals from it. At that, pre-treatment is performed by supplying separate solutions or mixture of solutions containing surface active substance and hypochlorite to the pile. Treatment with the leaching solution is performed by means of the solution obtained by mixing in the pile volume at supply to it of separate solutions or mixture of solutions containing hypochlorite, surface-active substance and/or mineral acid. In the leaching solution there used are mixtures of mineral acids or in-series introduced mineral acids. Supply points of the above solutions to the pile can be different.

EFFECT: increasing the efficiency of the process cycle at reduction of costs and emission of hazardous gases.

5 cl, 9 tbl, 6 ex

FIELD: mining.

SUBSTANCE: method of bath-well leaching of metals from ores includes treatment of mineral mass by solution of leaching in baths and metal winning from product solution. Baths are formed along leached mass, in the baths bottom a system of injection and extraction wells is built located above the level of bath with depth not less than the lower point of leached layer of mineral mass, and baths are filled with agglomerated mineral mass or pulp prepared in advance from extracted material, mineral mass in baths is treated by solution of leaching, and metal is extracted from product solution. Reusable solution obtained after metal extraction is strengthened or replaced with solution of another composition and is supplied to the system of injection wells for leaching of lower layers of material, then working solution is pumped off with leached metal through the system of extraction wells and metal is extracted from it; for leaching of lower layers of material solutions of environmentally safe chemicals, such as chlorides or thiosulfates, are used.

EFFECT: invention allows improving metal extraction efficiency.

FIELD: metallurgy.

SUBSTANCE: invention can be used in the technology of obtaining the compounds of rare-earth metals at complex processing of apatites, and namely for obtaining of concentrate of rare-earth metals (REM) from phosphogypsum. Method involves sorption of rare-earth metals. At that, prior to sorption, phosphogypsum is crushed in water so that pulp is obtained in the ratio Solid : Liquid=1:(5-10). Sorption is performed by introducing to the obtained pulp of sorbent containing sulphate and phosphate functional groups, at the ratio of Solid : Sorbent=1:(5-10) and mixing during 3-6 h.

EFFECT: increasing REM extraction degree to finished product.

5 tbl, 5 ex

FIELD: metallurgy.

SUBSTANCE: method involves leaching of cadmium from raw material in solution of sodium ethylene diamine tetraacetate with its further extraction from solution and regeneration of ethylene diamine tetraacetate. Cadmium leaching is performed in two stages. The solution obtained at the first stage is supplied for extraction of cadmium, and residue of the first stage is supplied to the second cadmium leaching stage. The solution obtained at the second stage is used for leaching of cadmium from raw material at the first stage. Besides, leaching at the second stage is performed in presence of hydrogen peroxide at maintaining its concentration in the range of 10-15 g/dm3 during 2-2.5 hours.

EFFECT: increasing cadmium extraction degree.

2 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: method includes joint leaching and activation of raw materials in a cage mill with extraction of metals into a solution simultaneously with crystal damage. After leaching and activation in a cage mill the material is laid into stacks, piles or trenches, treated with a solution of sulphuric acid. After treatment with a solution of sulphuric acid the material is washed with water, afterwards leaching is carried out with solutions of reagents. At the same time treatment of the material in stacks, piles or trenches is carried out with a solution of sulphuric acid with concentration of 10-30 g/l. Leaching of the material in stacks, piles or trenches is carried out with a solution of a sodium sulfide trioxosulfate with concentration of 10-20 g/l.

EFFECT: higher efficiency of metals extraction from mill tailings due to additional chemical treatment of mechanically chemically activated structural components of extracted materials after their extraction in a cage mill.

3 cl, 4 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method includes joint leaching and activation of raw materials in a cage mill with extraction of metals into a solution simultaneously with crystal damage. Prior to supply of raw materials into the cage mill, it in the mixture with elemental sulphur is previously treated with a solution of a mixture of sulphuric and nitric acids. Raw materials are mill tailings in the form of a pulp at the weight ratio of a solid phase to a liquid phase equal to 1:2. At the same time they are ground in the mixture with elemental sulphur in the amount of 12% relative to the mass of tailings to the size of 100% - 0.01 mm. Pulp treatment with a mixture of sulphuric and nitric acids is carried out at the weight ratio of the latter equal to 2:1 to bring the hydrogen index pH to the value of 1 with its further increase to the value 3 for 2 hours.

EFFECT: higher efficiency of metals extraction from mill tailings due to increased chemical activity of the latter.

2 cl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method includes leaching of useful components from open grains of processed raw materials in a cage mill, when loading raw materials and leaching reagent simultaneously in it. Raw materials processed in the cage mill are additionally exposed to vibration in the horizontal plane with its tossing. At the same time exposure to vibration is carried out within the frequency of oscillations from 30 to 1500 Hz at amplitude of horizontal oscillations from 2 to 50 mm and amplitude of vertical tosses of up to 30 mm.

EFFECT: higher efficiency of metals extraction from mill tailings or off-grade raw materials due to considerable increase of leaching speed.

7 dwg

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of hydraulic metallurgy and may find wide application in metallurgical industry. The method for complex processing of iron ore with high content of magnesium compounds consists in the fact that prior to annealing the initial ore is treated with a demagnetising acid agent. The acid agent used is an anhydrous phosphoric acid. After treatment the mixture is exposed to oxidising decarbonising annealing at the temperature of above 650C. The produced ash is treated with 10% aqueous solution of sulphuric acid, leached with water to produce pH of 6.5-7.0 in last portions of washing water. After leaching the concentrate is separated from washing water, dried and sent for iron smelting. Washing water is treated with ammonia until complete deposition of magnesium-ammonium phosphate, which after drying is sent for making fertilisers. The remaining aqueous solution is treated with quicklime to produce calcium sulfate residue, which is then dried and sent for use as a binding material. The remaining water is returned for leaching.

EFFECT: higher content of iron in a concentrate with simultaneous controlled reduction of magnesium oxide content in it.

1 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to electrolytic production of metallic lead from sweet lead paste that makes active part lead-acid accumulator. Method comprises the following steps: a) leaching of sweet paste by bringing it in contact with solution containing ammonium chloride to obtain solution after leaching and discharge of CO2 gas; b) separation of first solid residue and first clarified solution after leaching from step (a); c) leaching solid residue separated at step (b) by bringing it in contact with solution comprising ammonium chloride and hydrogen peroxide; d) separation of second solid residue and second clarified solution after leaching from solution after leaching from step (c); e) combining first clarified solution after leaching from step (b) with second clarified solution after leaching from step (d) to produce single solution; f) electrolysis of solution from step (e) in flow-through cell at current density of 50 to 10000 A/m2. Note here that electrolysis brings about mossy lead. Invention relates also to method of desulfonation of said paste.

EFFECT: higher yield and efficiency, simplified process.

26 cl, 6 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to mineral stock processing and may be used for extracting gold fractions of grain size smaller than 0.07 mm. Proposed method comprises preparing water suspension with addition of flocculating agent. Damped ground paper bulk is added to said suspension, paper bulk features reduced moisture resistance and mineral component-to-bulk ratio making 1: 0.05. Then, mix is mixed in mixer for 10 s. After mixing, paper bulk is separated on sieve with mesh size not exceeding 0.2 mm. Now, paper bulk is rinsed to produce concentrate to be dried and fused.

EFFECT: higher efficiency, lower costs.

1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the chemical industry, particularly to preparation of antiseptic agents for protecting wood and articles made from wood, as well as non-metal materials from biodecomposition, as well as from rotting, decomposition by microbes, fungi and insects. The method of preparing an antiseptic agent for protecting wood from rotting and decomposition involves mixing a solution containing an arsenic compound with chromium and copper compounds in ratio of arsenic to chromium and copper in the obtained product equal to 1:(0.6-1.5): (0.3-0.8).The solution which contains the arsenic compound is obtained by water leaching dry or hydrolysed sodium arsenite in ratio hydrolysed sodium arsenite to water equal to 1:(2-2.5). Hydrolysed sodium arsenite is obtained from a lewisite detoxification reaction mass.

EFFECT: wider raw material base when recycling products of detoxifying toxic substances.

2 ex

Up!