Method of controlling process of biooxidation of sulphide concentrates
SUBSTANCE: method includes controlling flow of air fed for biooxidation and the rate of mixing in a tub where biooxidation is carried out, based on concentration of divalent iron ions in a pulp, while ensuring a near zero concentration value. When the concentration of divalent iron ions in the pulp increases to more than 0.5-1.0 g/dm3, the flow of air fed for biooxidation and the rate of mixing are increased. In the absence of divalent iron ions in the pulp, the flow of air fed for biooxidation and the rate of mixing are reduced until traces of divalent iron ions appear to a near zero concentration.
EFFECT: simple, accurate and fast control of the process of biooxidation of sulphide concentrates, high redox potential and efficiency of biooxidation of sulphide concentrates, low power consumption of biooxidation.
The invention relates to hydrometallurgy of non-ferrous and noble metals, namely the extraction of metals from sulphide ores and dressing products, in particular products and wastes from mining and metallurgical industries, mineral waste, including concentrates, middlings and tailings, slag, sludge, cinders, etc. the Invention can be used for the extraction of copper, zinc, Nickel, etc. in the leaching solution, followed by extraction of metals from solution, for opening the gold, silver and other precious metals, finely disseminated in sulphide for the purpose of increasing their removal in subsequent processes.
Biooxidation of sulfide ores and concentrates is the least costly and not environmentally stressful way of leaching and the opening of the metals, as is carried out at atmospheric pressure, a primary oxidant, ferric ions Fe(III) in sulfuric acid formed in the reaction zone the oxidation of ions of Fe(II) aerobic autotrophic or mixotrophy zhelezookisnye bacteria.
One of the main parameters that determine the speed and efficiency of bacterial oxidation of ferrous iron and sulphide oxidation ferric ions, is the flow of air or other oxygen-containing gas, in particular who�ear, enriched with oxygen and/or carbon dioxide. For the dissolution of oxygen and carbon dioxide on the oxidation air is dispersed through the aerators under stirring device, so the dissolution of oxygen and air consumption biooxidation depend on the intensity of mixing design and speed of rotation of the mixing devices.
The air flow in the biooxidation of sulphide concentrates and the intensity of mixing is determined at the design stage and is not regulated by changes in the composition of sulfide concentrates, the content of the solid phase, performance (load), etc.
In the most familiar ways of biooxidation of gold-bearing sulphide concentrates with the participation Glazovskaya mesophilic bacteria "BIOX@process" (US No. 4822413, publ. 04.06.1987) and thermotolerant bacteria "BacTech@process (AU No. 652231, publ. 21.10.1992) total airflow is constant and does not adjust when you change the mineral composition of the concentrate, the content of solid phase in the leaching speed of the process and environment parameters.
In the methods of processing of sulphide copper-zinc products (RU # 2203336, publ. 05.03.2002 and RU №2005113258, publ. 20.10.2006) using bacteria, the intensity of aeration and mixing of specified volumetric mass transfer coefficient for oxygen in the range of 200-800 h-1without specifying how e�about handling.
In the method of processing of primary gold sulfide ores BIONORD (RU # 2256712 SS 11/00, 3/18, publ. 20.07.2005) aeration of the pulp in the bio-oxidation is carried out with compressed air with constant specific flow rate of 0.5 m3/m3.
In the method for processing refractory gold-arsenic ores and concentrates BIOS (EN 2234544, publ. 20.08.2004) the use of aerators, providing at constant air flow rate oxygen concentration in the slurry is not less than 2-3 mg/l, and does not take into account the activity of the biomass on the oxidation of iron.
The closest analogue is a method of controlling the process of biooxidation of sulphide concentrates (EA 200800805, publ. 30.10.2008), including regulation of the flow rate of the air supplied to the oxidation, and energy on electric mixers, i.e. the intensity of mixing in the tank, where biooxidation conducted on the basis of the measurement or calculation of oxygen consumption depending on the mineral composition of sulphide concentrate.
Determination of oxygen consumption by this method is not really characterizes the necessary amount of oxygen for bio-oxidation of iron and sulfide concentrates. Oxygen consumption calculated on the basis of the calculation depending on the composition of the sulfide material and the expected rate of oxidation, can be used in the design of the aeration system d�I estimate the marginal and average values of air flow rate, as only partially reflects the real conditions of biooxidation, for example does not take into account important indicator of biooxidation as the activity of the biomass in the oxidation of iron.
Oxygen consumption based on the measurements supplied to the reactor of oxygen, the dissolved oxygen concentration in the environment and the oxygen concentration in the exiting gas is not precisely determines the necessary amount of oxygen for the oxidation. For example, a high concentration of dissolved oxygen indicates that oxygen consumption is small and it can be reduced, but at the same time is a sign of good conditions of mass transfer in gas-liquid, and may be the reason for the low activity of the biomass and the rate of biooxidation, compounded by reducing the flow of oxygen.
Used energy consumption per unit mass of sulphide material does not reflect the effectiveness of biooxidation. The implementation of this method is complicated, as it requires a large amount of instrumentation and controls, application for determination of control parameters sealing bioreactors.
The technical result achieved by the present invention is more simple, precise and operational management of the process of biooxidation of sulphide concentrates with the participation Glazovskaya microorganisms. Additional re�ulticom the implementation of the method can be increased redox potential and effectiveness of biooxidation of sulphide concentrates, and reducing energy consumption for biooxidation.
Said technical result management process of biooxidation of sulphide concentrates with the participation Glazovskaya of microorganisms is achieved by regulating the flow rate of the air supplied into the slurry in the oxidation, and the rate of mixing of the pulp in the VAT, depending on the concentration of ions of bivalent iron in the slurry, thus increasing the concentration of divalent iron in the pulp than 0.5-1.0 g/DM3airflow and agitation of the pulp increases, and in the absence of ions of bivalent iron in the pulp flow and the mixing speed is reduced to the appearance of traces of ions of bivalent iron.
Oxygen is used by aerobic bacteria as acceptor in the chain of electron transfer in the oxidation of iron, and for the oxidation of ions of bivalent iron to trivalent, which is the oxidant of sulfide.
The oxidation reaction of iron from divalent to trivalent, with the participation of oxygen (1) catalyzed zhelezookisnye bacteria has a greater velocity compared to the speed of other reactions that occur during the bio-oxidation of sulfide minerals, for example reactions of oxidation of arsenopyrite and pyrite (2), (3), so the presence of ferrous iron in the liquid phase of biocycle�I indicates the deficit of dissolved oxygen.
With a lack of dissolved oxygen in the process of biooxidation slowed and stopped, resulting in the solution appears ferrous iron, whose concentration increases with the increase in the deficit of oxygen, redox potential decreases, the rate of sulphide oxidation is reduced.
The lack of oxygen in the bio-oxidation may be a consequence of low income, and low mass-transfer characteristics of gas-liquid, and can be removed by increasing the flow of oxygen-containing gas or the rate of mass transfer gas-liquid, for example by increasing the degree of dispersion of oxygen-containing gas by increasing the mixing speed.
When you change the mineral composition of sulphide concentrates, the content of solid phase in the slurry bio-oxidation, performance, etc. the presence or absence of divalent iron in the pulp signals the need to regulate the flow of oxygen, or dissolved due to the mixing intensity.
By increasing the concentration of divalent iron in the pulp than 0.5-1.0 g/DM3for effective bio-oxidation air consumption biooxidation should be increased to the disappearance of bivalent iron.
If too much air flow� on biooxidation occurs coalescence of air bubbles, accelerate their recovery and exit from the apparatus and the reduction of dissolved oxygen and carbon dioxide, worsening conditions of work of agitators, stirrers "choke" in the formation of the cork gas mode, as a result, the bio-oxidation are reduced.
In the absence of divalent iron in the pulp of biooxidation of the air flow in the biooxidation and the mixing speed can be reduced, and as a result reduce energy costs by biooxidation.
Regulation of air flow rate and stirring speed on the concentration of divalent iron in the slurry is simple and sufficiently accurate method of controlling the process of biooxidation of sulphide concentrates and allows you to control promptly.
Managing the process of biooxidation of sulphide concentrates regulation of air flow rate and stirring speed, which provides the necessary amount of oxygen for bio-oxidation of iron and life of bacteria, but not significantly exceeding this amount can improve process efficiency and reduce operating costs for aeration.
The invention is illustrated by examples of the method.
Management of bio-oxidation of sulphide gold concentrate flotation beneficiation particle size is 100% of the class minus 0.074 mm, containing pyrrhotite 27%, �arsenopyrite 20%, the antimonite 7% pyrite 15% involving the Association Glazovskaya bacteria by regulating the flow of air in six vats with mechanical stirring and bubbling of air, depending on the concentration of ions of bivalent iron in the slurry reduces the flow of air as compared to the design performance in the first vats 1.2 times, in the 5th Chan 2.0 times, 6 Chan 2.4 times. The total air flow for biooxidation of the concentrate decreased 1.6-fold, respectively and decreased the cost of electricity for aeration.
The extent of biooxidation of gold-bearing sulphide concentrate was as follows: pyrrhotite and arsenopyrite 98-99%, antimonite 74%, pyrite 63%, the recovery of gold from Keck bio-oxidation cyanidation increased by 2.1% compared to the control experiment without a control process of biooxidation depending on the concentration of ions of bivalent iron in the pulp.
For bio-oxidation was used stale zinc-containing tailings of flotation beneficiation of size 65% class - 0,044 mm, containing 5.6% of zinc, 12,96% sulfur and 11.6% of iron, the main ore minerals are pyrite 25-30%, sphalerite 7-8%, pyrrhotite 7-10% and markesic, arsenopyrite, chalcopyrite, Galena - only 5-7%. Bio-oxidation of the zinc flotation tailings was carried out in continuous mode the cascade of three successive vats with mechanical paramashiva�education and aeration air, with the participation of the Association of mesophilic Glazovskaya bacteria in an aqueous solution of sulfuric acid at a pH of 1.5-2.1, the concentration of ferric iron 10,5-15,0 g/l, the solids content of 40%.
Managing the process of biooxidation of mill tailings by changing the speed of agitation of the pulp in vats depending on the concentration of iron ions in the pulp, with the appearance of ferrous iron in the pulp to a concentration of 1.0 g/l of the rotation speed of the stirrer was gradually increased from 350 to 400 rpm, and in the absence of ions of bivalent iron in the slurry, the speed of rotation of the agitator gradually decreased until the appearance of traces of iron ions. In the result management process for 98 hours of biooxidation of the extraction of zinc in the solution is increased compared to the control experiment was 2.7%.
A method of controlling the process of biooxidation of sulphide concentrates with the participation Glazovskaya of microorganisms, including regulation of the flow rate of the air supplied into the slurry in the oxidation, and the rate of mixing of the pulp in the VAT, characterized in that the flow rate of the air supplied to the pulp in biooxidation, and agitation of the pulp is adjusted depending on the concentration of ions of bivalent iron in the slurry, thus increasing the concentration of divalent iron in the pulp than 0.5-1.0 g/DM3the flow rate of the air supplied to the oxidation, and agitation of the pulp increases, and in the absence of ions of bivalent iron in the slurry, the flow rate of the air supplied to the oxidation, and the mixing speed is reduced to the appearance of traces of ions of bivalent iron.
SUBSTANCE: proposed method consists in subjecting of said concentrate to biological exposure without preliminary mechanical refining with the help of the complex of thione microorganisms. Obtained cake of biological exposure is subjected to wet magnetic separation to get sulphur-bearing solution of high-quality magnetite concentrate and tailings. Note here that biological exposure is performed with application of cultures of acidophilic thione microorganisms inherent in proper biocenoses of the deposit at S-to-L ratio of 1:5-1:7 at 15-45°C, initial values of Eh 650 mV, pH 1.5-2.15 and barometric pressure.
EFFECT: higher efficiency of dressing.
7 cl, 2 ex
SUBSTANCE: method includes preparation of ash and slag, mixing them with leaching solution, accumulation of biomass of microorganisms, bacterial leaching of rare earth and noble metals, separation of obtained suspension into sediment and clarified liquid with isolation of rare earth and noble metals from the latter. At the stage of accumulation of biomass of microorganisms saturated solution of calcium carbonate is added in amount 1-10% of leaching solution consumption. Bacterial leaching is performed in mode of multi-chamber floatation with aeration intensity 0.1-0.5 m3/m2·min. Intensity of aeration in each following chamber is reduced by 5-10% in comparison with the previous one. Bacteria of genus Acidithiobacillales are used as microorganisms. Floatation is performed with application of finely disperse aeration with average size of bubbles 20-30 mcm. Size of bubbles in any following chamber is increased by 10-15%.
EFFECT: increased extraction of rare earth and noble metals from ash and slag due to intensification of organism cultivation process.
4 cl, 3 ex
SUBSTANCE: installation for bacterial leaching of metals from technogenic wastes includes apparatus for accumulation of microorganism mass in liquid medium with technogenic wastes, apparatus for leaching metals from technogenic wastes, unit for separation of metals from liquid medium with technogenic wastes in form of apparatus for ionic floatation and unit for regeneration of leaching solutions in form of reservoir with pneumatic system of aeration. Apparatus for accumulation of microorganism biomass is equipped with turbine mixer and external cooling circuit. As apparatus for metal leaching, used is multi-chambered floatation apparatus with devices of flow of liquid medium with technogenic wastes from chamber to chamber, made with possibility of changing conditions of aeration and intensity of mixing.
EFFECT: increased degree of metal leaching from technogenic wastes.
5 cl, 5 dwg
SUBSTANCE: invention relates to biotechnology. Disclosed is a method of producing millerite by placing a pure culture of sulphate-reducing bacteria, which are resistant to copper ions and ions of other metals, into a synthetic medium containing metal salts, with addition of divalent nickel and nutrients, which include solutions of vitamins, potassium, ammonium, sodium and calcium salts, cofactors, lactate and sodium sulphate. Glycerine is added to the culture medium. Bacteria are cultured at temperature of 28°C. The formed precipitate, which contains millerite, is collected by centrifuging and then dried. Formation of crystalline millerite begins in 7 days and a stable crystalline millerite phase forms in 20 days.
EFFECT: method enables to obtain millerite which does not contain impurities of other sulphides in short culturing periods.
6 dwg, 3 tbl, 1 ex
SUBSTANCE: proposed method comprises grinding, gravity concentration of ore and processing of concentrate. Note here that ore is ground to 0.6 mm-particle size. Gravity concentration is carried out at straight-flow small-filling sluice to produce concentrate, commercial product and tails. Said concentrate and commercial product are subjected to bioleaching at separate cycles using bacterium complexes consisting of copper-adapted autotropic thionic bacteria Ac.ferrooxidans, Ac.thiooxidans in active growth phase. Degree in decrease in material directed to bioleaching at gravity concentration makes 1000-1500. Biological vat leaching is conducted at the number of bacteria making at least 107 cell/ml, S-to-L ratio of 1:5-1:9, active or moderate aeration and at 15-45°C for 90-120 hours.
EFFECT: efficient and nonpolluting process.
3 cl, 1 ex
SUBSTANCE: proposed method comprises ore pretreatment by crushing, classification and grading, biological degradation of ore silicate minerals by multiple ore interaction with silicate bacteria cultural medium without mixing with replacement of said cultural medium at pH, at least, 0.4. Then, metals are leached from biological degradation cakes by cultural solutions after extraction of silicon therefrom and additions of sulfuric acid to concentration of 50-450 g/l. After leaching, metals are extracted form cake leaching solution. Note here that cultural medium is replaced on reaching redox potential in solution of minus 250 mV. After biological degradation and before leaching, cakes are flushed with water.
EFFECT: higher degree biological degradation, yield of metals, and lower costs.
10 cl, 2 ex
SUBSTANCE: method for extracting copper from sulphide-bearing ore involves ore crushing, leaching of copper with water sulphuric acid solution at pH equal to 1.5-2.0 and temperature of 25-30°C in presence of thionic bacteria with air aeration. At that, crushing is performed up to ore fractions size of 10-25 mm. Prior to leaching, sulphide-bearing ore is treated with silicate bacteria at temperature of 25-30°C and pH=6-7.
EFFECT: improving copper extraction degree at leaching.
SUBSTANCE: method includes leaching of ground raw materials in a solution of sulphuric acid with concentration of more than 2.0 g/l, containing ions of trivalent iron of more than 10-12 g/l, while mixing, at the temperature up to 100°C, solid phase content to 60%, at least in two serially connected reservoirs. The pulp discharged from the last reservoir is separated into solid and liquid phases. At the same time the solid phase is returned for leaching into the first reservoir. Iron oxidation in the liquid phase is carried out with iron-oxidising bacteria adsorbed on a neutral carrier at the pH 1.4-2.2 and 90°C with aeration by gas containing oxygen and carbonic acid. Then the liquid phase is returned after iron oxidation into leaching reservoirs, and metals are extracted from the produced phases. Besides, leaching is carried out with aeration by oxygen-containing gas. The pulp discharged from each reservoir is separated into solid and liquid phases. The solid phase is sent for leaching to the next reservoir, and the liquid phase is prepared prior to oxidation with bacteria. Duration of leaching is increased in each subsequent reservoir.
EFFECT: higher speed of bacterial iron oxidation and efficiency of sulphides dissolution, reduced dimensions of devices for bacterial oxidation of iron.
13 cl, 3 ex
SUBSTANCE: invention relates to nonferrous metallurgy and may be used for recovery of solutions resulted from mineral stock leaning, particularly, for iron ions oxidation. Said tower comprises cylindrical body with solution feed and discharge branch pipes, and process automatic control system (PACS). Tower body is filled with carrier whereon sorbed are iron-oxidising microorganisms made up of solid porous material with developed surface. Note here that tower bottom is furnished with tank to house PACS transducers and solution feed control device.
EFFECT: increase in rate of oxidation of iron (II) to iron (III) from 3 g/lh to 15 g/lh.
1 dwg, 1 tbl, 2 ex
SUBSTANCE: method involves concentrate bio-oxidation with bio-pulp obtaining, its dehydration with cake obtaining and its processing with the extraction of gold. Bio-pulp dehydration is done by two-stage centrifuging. At the first stage 90-95% of bio-pulp is dehydrated with centrate of first stage obtaining that contains solid not more than 10-14 g/l and cake with moisture not less than 40%. Not less than 1 g/m3 of antifoaming agent is added to centrate obtained after first stage, the agent is selected from silicone organic antifoaming agents, for example, Penta® 474, and directed to the second stage of centrifuging at maintaining fluid level height in centrifugal drum not less than 10 mm with obtaining centrate that contains solid not more than 0.8 g/l. The cakes obtained after the first and second stage of centrifuging are combined and directed for further processing of gold extraction.
EFFECT: process intensifying and obtaining of more dry cake with low moisture content.
10 dwg, 2 ex
SUBSTANCE: invention relates to technology of obtaining zinc oxide and can be applied for obtaining zinc oxide with displaced isotopic composition. Method includes obtaining zinc hydroxide from diethylzinc, which is carried out in flow-type reactor in water or water pulp stream, containing zinc hydroxide, with consumption of diethylzinc up to 40 kg and hour with obtaining pulp, which contains zinc particles. Pulp is subjected to separation to separate it from reaction gases and re-supplied into reactor as hydrolysing agent. After pulp saturation zinc hydroxide is separated from water by settling. Zinc hydroxide is dried and decomposed to zinc oxide.
EFFECT: process safety which is achieved due to instant removal of heat and reaction products by water stream.
SUBSTANCE: invention relates to a method of pyrometallurgical processing of iron-containing materials, which involves loading to a melting zone of a two-zone furnace of iron-containing materials, fluxing additives and carbon-containing materials, their melting in an iron-containing melt bubbled with oxygen-containing air, afterburning of combustible gases leaving the melt with further supply of the melt to a reducing zone, to which carbon-containing materials and other charge materials are loaded; reduction of iron with formation of iron-carbon melt and slag; afterburning of combustible gases leaving the bath of the reduction zone; separate tapping of melting products. Gases leaving reduction and melting zones are cooled down and cleaned separately; with that, cleaned gases of the melting zone are removed to an exhaust pipe, and exhaust gases of the reduction zone after cooling and cleaning are compressed and supplied to tuyeres of the lower row of the melting zone.
EFFECT: reduction of specific consumption of energy sources.
SUBSTANCE: invention relates to hydrometallurgy and can be used for processing of concentrates, industrial products and solid wastes containing metals. Proposed process comprises leaching of cake 3 n, by HCl solution at 70°C and L:S ratio of 2. Note here that leaching is performed in the presence of table salt of concentration making at least 120-140 g/dm3.
EFFECT: intensified leaching, higher yield.
4 tbl, 2 ex
SUBSTANCE: method involves contact of an extractant and a solution, mixing of the mixture, sedimentation and separation of organic and water phases. Extraction is performed with vegetable oils. The process is performed at the ratio of water (WB) to organic (O) phase of W:O ≤ 7, pH 7-10 and adjustment of pH value during not more than 60 minutes.
EFFECT: high degree if efficiency of zinc extraction from water solutions with simultaneous economy and safety of the process.
7 dwg, 6 ex
SUBSTANCE: method of Waelz process of zinc cakes involves mixing and pelletisation of zinc cakes together with solid carbon-containing material and Waelz process of pelletised material. With that, to the mixing stage there supplied is mixture of calcium- and magnesium-containing materials at content of magnesium oxide in mixture of 20-50% and ratio in the charge (CaO+MgO)/SiO2=2÷4. Pelletisation of the mixture is performed together with solid carbon-containing material with fineness of less than 2 mm. Waelz process of pelletised material is performed with addition of carbon-containing material with fineness of more than 2 mm at the temperature of 1100°C. As carbon-containing material, wastes of coal and oil-processing industries are used.
EFFECT: increasing furnace capacity and reducing carbon-containing material consumption.
2 cl, 1 dwg, 5 tbl, 5 ex
SUBSTANCE: method involves crushing chemical cells, leaching, magnetic separation and electrolysis. The cells are crushed and leached with water in an atmosphere of carbon dioxide gas without access to oxygen. Light fractions are then removed from the scrap by floatation. Filtration is then carried out. The filtrate is treated with sorbents. After filtration, the scrap is washed with water, dried and fragments of ferrous and nonferrous metals are removed by electromagnetic separation, and then leached with sulphuric acid solution. Sulphuric acid pulp is filtered through a filter with an inert material, a filter with a coal medium and a filter with a cation-exchange medium. Ions of row d and row p metals sorbed by a cation-exchange resin are selectively desorbed with sulphuric acid solutions. Solutions containing ions of row d metals are subjected to electrolysis, and solutions containing ions of row p metals are neutralised to pH 3-4 and treated with clay mineral sorbents. The precipitate after sulphuric acid leaching is leached with nitric acid solution; the undissolved manganese dioxide precipitate is removed and the filtrate is neutralised and acidified to pH 3. The precipitate is filtered off. The filtrate containing mercury ions is subjected to cathode reduction and the precipitate containing lead and silver chlorides is dissolved in nitric acid and subjected to cathode reduction in an electrolysis cell with separate deposition of metals on electrodes.
EFFECT: environmental safety of recycling any type of spent chemical cells.
SUBSTANCE: invention relates to the field of hydrometallurgy of heavy non-ferrous metals. The method for processing of sludges of neutralisation of acid mine waters includes its preliminary grinding, afterwards sulfuric leaching is carried out during mixing by means of treatment of the sludge with acid mine waters and sulfuric acid and addition of iminodiacetatic ampholyte for simultaneous sorption of copper and zinc. Ampholyte is separated from the produced pulp, and its desorption is carried out with sulfuric acid with formation of desorbed iminodiacetic ampholyte and sulfate solution. The desorbed ampholyte is returned to the stage of leaching and simultaneous sorption. From the sulfate solution by means of electrolysis copper is serially extracted, and then - zinc. The treated sulfate solution is returned to the stage of desorption. The produced pulp after separation of ampholyte from it is neutralised with lime, afterwards it is separated with solid residue and liquid part. The remaining solid residue is dried and ground with production of a gypsum-containing end product.
EFFECT: provision of development of a wasteless technology, which ensures extraction of copper and zinc from sludges of neutralisation of acid mine waters into end products and production of an additional end product - a binder for production of construction materials.
1 dwg, 7 tbl
SUBSTANCE: invention relates to the method for extraction of metals from metal-containing sulphide mineral raw materials. The method includes leaching with mixing of a sulphuric acid solution in presence of trivalent iron ions in at least two serially connected tubs, separation of leaching products into liquid and solid phases, iron oxidation in a liquid phase, return of the liquid phase after iron oxidation into leaching reservoirs, intermediate extraction of metals from liquid phases. At the same time the initial raw materials prior to leaching are exposed to preliminary acid treatment at PH=0.8-1.4, S:L=1:1. Leaching is carried out in two stages at the temperature of 75-95°, PH=1.0-1.2 and S:L=1:(3-6), concentration of trivalent iron ions of 30-45 g/l at each stage with separation of leaching products after each stage into liquid and solid phases and iron oxidation in a liquid phase after each stage and with extraction of metals at each stage from liquid phases after iron oxidation. To the first stage raw materials exposed to preliminary acid treatment are sent, and to the second stage - a solid phase is sent, produced after separation of leaching products at the first stage. The liquid phase, which was produced after oxidation of iron at the second stage, is returned to the last leaching reservoir of the same stage.
EFFECT: higher extent of extraction of all precious metals into a solution and reduction of process duration by 1,2-1,5 times.
4 ex, 1 dwg
SUBSTANCE: invention relates to pelletising using stock consisting of iron ore or dust bearing metal oxides and may be used in production of reduced metal and separation of volatile metals, say, zinc and lead. First, pellets are produced using metal oxide powder containing iron oxide and, at least, one of zinc oxide, lead oxide and titanium oxide, to be compacted into briquettes. Total content of one of aforesaid oxides makes 10 wt % or more. Prior to compacting into briquettes, said pellets are dried to reduce moisture content by 50-95 wt %.
EFFECT: higher strength.
35 cl, 4 dwg, 2 tbl, 11 ex
SUBSTANCE: first, the ore is supplied to a cycle of the main lead-zinc flotation accompanied by foam-producing agent supply, a sulphydric collector and zinc minerals depressing agent that does not contain cyanide. The resulting crude lead-zinc concentrate is subjected to cleaning lead-zinc flotation, a lead-zinc concentrate and lead-zinc middlings are obtained, processed in a cycle of lead-zinc flotation of middlings. Final tailings are obtained that contain pyrite and lead-zinc concentrate. In the second yield of the cycle of the main lead-zinc flotation the product is obtained which is then subjected to further flotation in the cycle of primary zinc flotation that yields rough zinc concentrate and final tailings. The rough zinc concentrate is processed during cleaning zinc flotation that yields commercial zinc concentrate and zinc middlings. The zinc middlings from the cleaning zinc flotation cycle is supplied to the cycle of zinc flotation of middlings that yields final tailings and zinc concentrate. The lead-zinc concentrate of the cleaning lead-zinc flotation cycle and concentrates from the cycles of lead-zinc and zinc middlings flotation are combined and sent to hydrometallurgical processing.
EFFECT: production of metallic zinc, lead concentrate and silver dore alloy.
14 cl, 1 tbl, 1 ex
SUBSTANCE: method includes converting chloride complexes of iridium (III) into an iridium (IV) complex which is well extractable with tributyl phosphate by mixing a chloride solution of a platinum-group metal with a solution of hypochlorous acid in tributyl phosphate at 5-50°C. During the extraction process, the excess chloride ion in the form of molecular chlorine is simultaneously removed from the solution and iridium (III) is oxidised to iridium (IV). Extraction of iridium into the organic phase is 93-95%, and platinum, palladium, rhodium and ruthenium are virtually not extracted. Re-extractio of iridium from the organic phase is carried out using water or weakly alkaline aqueous solutions.
EFFECT: selective extraction of iridium from chloride solutions of platinum-group metals.
2 cl, 4 tbl, 4 ex