Method of extracting rhenium and platinum metals from spent catalysts on aluminium oxide supports

FIELD: chemistry.

SUBSTANCE: method includes oxidising roasting, percolation leaching of the roasted product with aqueous solution of an oxidising agent or mixtures of oxidising agents to obtain a rhenium-containing solution and an insoluble residue, sorption of rhenium from the rhenium-containing solution in a separate apparatus, drying the insoluble residue, mixing with fluxing agents and fusion on a metal collector. Percolation leaching is carried out at redox potential values of 900-1100 mV and temperature of 50-90°C, with simultaneous sorption of rhenium, followed by desorption and separation of rhenium compounds or rhenium metal from the strippant. The fluxing agents used to fuse the insoluble residue are fluorspar, sodium carbonate and sodium nitrate. Fusion is carried out at temperature of 1200-1800°C on a metal collector in several steps, while discharging the formed slag after each step and fusing the next portion of the mixture on the collector from the previous fusion with separation of the alloy of platinum metals with the collector.

EFFECT: high degree of extraction of rhenium, low reactant consumption, labour input, faster processing of the material, considerable reduction of the volume of solutions which require recycling.

8 cl, 1 dwg, 1 ex

 

The invention relates to the metallurgy of noble and rare metals and can be used in the processing of the deactivated catalysts based on alumina containing platinum group metals and rhenium.

There are a large number of methods of processing of the deactivated catalysts containing platinum metals [Majorityof, Alexei Orlov. Metallurgy of noble metals (foreign experience). - M.: metallurgy, 1990, s-343]. However, the use of these methods for processing catalysts, containing, along with the platinum metals and rhenium, encounters considerable technical difficulties and is associated with large losses of the latter.

Overview of processing methods of the deactivated catalysts based on alumina shows that these methods can be divided into three main groups:

- dissolution of the foundations of the catalyst receiving and further processing of the concentrate extracted components;

- dissolution of the recoverable components of the acid with oxidizing agents with the following processing solutions, as a rule, sorption methods;

melting catalysts on metal collector.

The first two methods are not universal, as the basis of the catalyst is aluminum oxide is the most common in two versions - alpha-form and ha is mA-form. Typically, these two forms are mixed. The alumina in the alpha form is poorly soluble in acids and alkalis, which does not allow you to get rich concentrates in the first group of methods. The alumina in the gamma form, soluble in acids, which leads to increased consumption of reagents and difficulties in filtering slurries, if methods are applied from the 2nd group. In the third group of methods is very likely loss of rhenium, because at high temperatures the rhenium is easily oxidized, becoming volatile rhenium trioxide - Re2O7.

Known solution EN 2261284 C2 (publ. 27.09.2005), which opened the way for the complex processing of deactivated latinoreview catalysts based on alumina, including high-temperature annealing at a temperature of 1200÷1300°C for the translation of aluminum oxide in low alpha form, the capture of the resulting rhenium oxides of the alkaline solution and the extraction of platinum metals by leaching of the calcine in a solution of hydrochloric acid in the presence of an oxidizing agent (sodium hypochlorite, hydrogen peroxide or elemental chlorine).

In the patent RU 2398899 C1 (publ. 10.09.2010) described a two-stage firing, first at a temperature of 600-850°C to remove residual carbon, and then at a temperature of 1200-1300°C.

The disadvantages of these methods are high firing temperature, requiring bol is the high energy consumption, the necessity of establishing an effective system for capturing volatile oxides of rhenium, significantly complicating the process, the formation of a large number of solutions requiring disposal.

There is a method of extraction of rhenium from aluminium oxide-platinum catalysts (Thematic review. The extraction of valuable metals from used heterogeneous catalysts, Tsniiteneftehim, M., 1988, s, 3rd par.), the catalysts are subjected to oxidizing roasting at 300-500°C. At this temperature is burning carbon.

The calcined catalyst leached 5M hcl (nitric) acid or Imperial vodka at temperatures of 20-90°C. the Allocation of precious metals from solution are realized by means of ion exchange. The disadvantage of this method is that the firing temperature of the catalyst is insufficient for distillation, rhenium, and translate the alumina in the alpha form, resulting in a significant portion of the aluminum goes into the leaching solution. This greatly increases the flow of leaching reagent leads to the formation of very truefilter slurries reduces the extraction of platinum in the finished product.

There is a method, which includes stages: the burning 500-600°C, leaching in sulfuric acid, the cementation of platinum on the Al powder with the Department sulfate solution from the insoluble residue. Rhenium is extracted from plants is ora sorption on the slightly basic anion exchange resin, and from the insoluble residue extract platinum (V. Bukin, Igumnov, MS, Safonov V.V. and other Processing of industrial waste and recyclable materials containing rare, precious and base metals. M.: Izd. home "Business capital", 2002, s).

The disadvantages of this method:

- high consumption of sulphuric acid on the dissolution of the foundations of the catalyst;

- difficulty in separating sulfuric acid solution from the insoluble residue due to the formation of colloidal precipitation of platinum and aluminum oxide on stage leaching;

- the need to wash the cake from the sulfuric acid leaching of the catalyst;

the lack of clear separation of platinum and rhenium on stage leaching the roasted product and, hence, the need for more selection of platinum from the obtained solutions;

incomplete dissolution of the basis of the catalyst, if the latter is partially or entirely composed of aluminum oxide in the alpha form, which reduces or nullifies the degree of concentration of platinum metals in insoluble residue and complicates further processing;

- the need for disposal of large quantities of sulfuric acid solutions.

In the application EN 2003103936 A (publ. 27.08.2004) disclosed a method of extracting platinum group metals and rhenium from a spent catalyst. The method includes wimalasiri the hydrochloric acid solution, containing active chlorine, in the presence of granular macroporous weakly basic anion exchange resin in the polymer matrix (sorption leaching), subsequent separation of the anion exchange resin from the mixture solution and a solid residue, and the desorption of platinum metals together with rhenium aqueous solution of ammonia, the separation of rhenium from the platinum metals by sorption of ammonia decorate on strong-base anion exchange resin followed by desorption and release of decorate rhenium in the form of ammonium perrhenate.

The disadvantages of this method:

no oxidative calcination at that organics, inevitably present in the catalyst, is a natural sorbent and, remaining in the residue sorption leaching reduces the extraction of rhenium and platinum;

the necessity of grinding the source of catalyst, or after sorption leaching impossible to separate the pulp and the sorbent;

- there is no transfer of alumina in the alpha form, which leads to high consumption of acid because of its high solubility in acid alumina in the gamma form;

in the process leach method, which is implemented with vigorous stirring, the sorbent (including saturated recoverable metals) partially destroyed and remains in the residue of the leaching, thereby reducing the extraction of rhenium and PLA is enodev;

- a large amount of solutions requiring disposal.

In the patent RU 2306347 C1 (publ. 20.09.2007) described a method of processing catalysts containing platinum group metals and rhenium on the native oxide of aluminum. The method comprises the stage of: firing (calcination) of the deactivated catalyst containing platinum and rhenium on alumina at 500÷600°C in an atmosphere of air, leaching in sulfuric acid at 135°C, the dilution water. In order to accelerate the separation of sulfuric acid solution from the insoluble residue after leaching the resulting slurry added to the concentrate electrostatic dust refining production (KPIs) in an amount of 30-60 kg/m3on dry basis, cement Al powder and separating the insoluble solid phase of the pulp by filtration on filter paper to obtain the insoluble residue and sulfuric acid solution containing rhenium (90%), the latter sent for sorption on the resin, the insoluble residue is dried at 100°C and then used for extraction of platinum metals by the method of concentration and separation of melt: add flux (crushed silicate-sodium powder, soda ash, calcium oxide) and carbon reductant - toxic load in Lundby melting crucible (crucible of fused aluminum oxide) at a temperature of 1300°C. At this as a collector noble is yellow mentioned copper header.

The disadvantages of the above method are:

- high consumption of sulphuric acid on the dissolution of the foundations of the catalyst;

- to speed up filtering the pulp after the sulfuric acid dissolution fundamentals of catalyst is used, the concentrate electrostatic dust refining production of a particular company and, therefore, other companies this technological method impracticable;

the lack of clear separation of platinum and rhenium on stage leaching the roasted product and, hence, the need for more selection of platinum from the obtained solutions;

incomplete dissolution of the basis of the catalyst, if the latter is partially or entirely composed of aluminum oxide in the alpha form, which reduces or nullifies the degree of concentration of platinum in the insoluble residue and complicates further processing;

- the need to wash the cake from the sulfuric acid leaching of the catalyst;

- the need for disposal of large quantities of acid (in this case sulfuric acid solutions);

- sophisticated separation technology of rhenium and platinum.

This method is the closest to the proposed method and adopted for the prototype.

The problem to which the present invention is directed, is to increase the effectiveness of the lane is the elaboration of the deactivated catalysts based on alumina, containing rhenium and platinum group metals, by increasing the degree of extraction of precious metals and rhenium, reduced reagent consumption, the volume of recyclable waste, reduce process time and energy consumption and labor costs.

Proposed according to the present invention, the method of extraction of rhenium and platinum group metals from spent catalysts on the native aluminum oxide includes oxidative calcination of catalyst leaching of the resulting calcine aqueous solution of the oxidizing agent with obtaining registertimer solution and the insoluble residue, the sorption of rhenium from registertimer solution by ion-exchange resin, drying the insoluble residue, the subsequent rihtovanie insoluble residue from the flux and melting of the charge on the metal collector.

A distinctive feature of the proposed method from the closest analogue is that the candle is subjected to percolation leaching with an aqueous solution of an oxidant or mixture of oxidants when the value of the redox potential, 900÷1100 mV, and the temperature of 50-90°C with obtaining insoluble residue and registertimer solution with simultaneous sorption of rhenium from registertimer solution on macroporous weakly basic ion-exchange resin in a separate apparatus, followed by desorption of rhenium and the selection of decor the ATA connection rhenium metal or a rhenium. For melting the dried insoluble residue as fluxes using fluorspar, sodium carbonate, sodium nitrate in the ratio (parts by weight) insoluble residue:fluorspar:sodium carbonate:sodium nitrate=1:0,05÷0,5:0,03÷0,1:0,01÷0,03, the mixture obtained by mixing the insoluble residue from the above fluxes are melting at a temperature of 1200÷800°C on the metal collector, while melting lead in several stages, blending after each stage the formed slag and propleurae another portion of the charge on the collector from the previous melting emitting alloy of platinum metals with header.

Oxidative calcination of the catalyst is generally carried out at a temperature of 450÷600°C, preferably in a rotary tube furnaces.

Percolation leaching of the calcine in the apparatus, preferably in the form of a filled candle vertically installed columns (hereinafter percolator) is conducted with an aqueous solution of an oxidant or mixture of oxidants, such as chlorine, bromine, hydrogen peroxide, chlorates, perchlorates of alkali metals when the value of the redox potential of the solution, 900÷1100 mV, and temperature of 50÷90°C. When used as an oxidizer chlorine leach solution obtained by barbotage chlorine gas through a layer of water, preferably directly into the supply tank. The prepared solution on the of elites or mixture of oxidants served, preferably, in the lower part, and is removed from the top of percolator over time, while the concentration of rhenium on the exit percolator will not decrease to values less than 1 mg/l, which provides the residual concentration of rhenium in the insoluble residue less than 0.01%, after which the insoluble residue from percolator unload. In percolator load the next portion of the candle and continue leaching. Platinum group metals and base catalyst under these conditions is not completely dissolved and remain in the insoluble residue. Below are examples of chemical reactions describing the process of dissolution of rhenium leaching of calcine:

2Re+7H2O2→2HReO4+6H2O

2Re+7Cl2+8H2O→2HReO4+14HCl

8Re+7HClO4+4H2O→8HReO4+7HCl.

Sorption of rhenium produced by leaching registertimer solution (solution of rhenium acid or perrenate alkali metal) is performed on macroporous weakly basic ion-exchange resin in a separate apparatus, preferably, ion-exchange column, and the sorption of rhenium on the loaded ion exchange unit volume of resin lead to the discovery of rhenium in coming out of the machine solution - sorbate - in a concentration of not more than 10 mg/L. then saturated resin is directed to the operation desorption rhenium, and sorption continue on the fresh or regenerated resin Sorbate collect, are adjusting the concentration of the oxidant in it until the ORP 900÷1100 mV and use the resulting solution to the leaching of the calcine again (several times), thereby providing a high recovery of rhenium due to the receipt of the leaching solution, practically free of rhenium, and at the same time preventing the watering process.

Desorption of rhenium from rich rhenium resin is carried out with aqueous ammonia. From decorate known ways to get targeted products in the form of compounds of rhenium metal or a rhenium.

Drying the insoluble residue after extraction of rhenium is conducted usually at a temperature of 100÷300°C.

Furnace for melting is prepared by mixing the insoluble residue from the flux - Fluor-spar, sodium carbonate, sodium nitrate in the ratio (parts by weight) insoluble residue:fluorspar:sodium carbonate:sodium nitrate=1:0,05÷0,5:0,03÷0,1:0,01÷0,03.

The melting of the charge on the metal, preferably copper, the collector is carried out at a temperature of 1200÷1800°C (if necessary in the process of melting the possible additive borax, lime, quartz sand to liquefy toxins), while the melting of the charge lead in several stages, blending after each stage the formed slag and propleurae another portion of the charge on the collector from the previous melting emitting eventually slag and alloy manifold with platinum meta is Lamy. The content of platinum metals in the slag in an amount not greater than 0.005%, and the total loaded up drain metal calculated so that the final total concentration of platinum metals in the reservoir was 10÷20%.

Processing of the obtained alloy is carried out by known methods, for example by dissolving the alloy in acid, preferably nitrogen, to obtain a concentrate of platinum metals and followed by dissolving the concentrate in Aqua Regia or hydrochloridebuy and further, the classical technological scheme.

The method is as follows.

The feedstock is deactivated catalysts on alumina based fired in kilns or in other furnaces of the type with access of air at a temperature of 450÷600°C for a burning out of the organic component, the calcine is loaded into percolator and through the layer of cinder pumped from the supply tank is heated to a temperature of 50÷90°C aqueous solution of an oxidant or mixture of oxidants with ORP 900÷1100 mV. When rhenium is oxidized and converted into solution in the form of rhenium acid or perrenate alkali metal base catalyst and the platinum solution does not react. Registergui solution percolator passes through the sorption column, filled with slightly basic macroporous resin, where the rhenium SOR is associated to the resin, and the solution is returned to the pressure vessel, where it becomes stronger oxidant or mixture of oxidants, is heated to a temperature of 50÷90°C and fed back into percolator. Thus, through the layer of catalyst is continuously pumped hot solution, practically free of rhenium, which allows a high degree of extraction to allocate the rhenium solution eliminates the need to wash the insoluble residue, and the solution can be used repeatedly. Rhenium with resin is desorbed ammonia solution, then is quite concentrated on the rhenium desorbed in the form of a solution of ammonium perrhenate, which is processed by known methods to obtain the target product. The insoluble residue after extraction of rhenium is unloaded from percolator, dried in a drying furnace at a temperature of 100÷300°C and sitout with flux in the ratio of insoluble residue:fluorspar:sodium carbonate:sodium nitrate=1:0,05÷0,5:0,03÷0,1:0,01÷0,03. The charge portions are loaded into the melting furnace for pre-molten collector, heat the contents of the furnace to a temperature of 1200÷800°C to obtain a flowable slag. When the need for additional dilution of toxins add small amounts of borax, lime, quartz sand. The slag is drained, leaving the manifold in the oven, on the collector load the next portion of the charge, and so forth the Total amount loaded on the melting insoluble residue after extraction of rhenium calculated on the basis of to the concentration of platinum metal in the reservoir has reached 10÷20%. The latest products of melt poured into the mold and after cooling, the slag is separated from the manifold. Slag will test and implement waste. Collector granularit, leached in an acid solution, preferably nitrogen, the resulting concentrate platinum officeroute by known methods, for example by dissolving granules of alloy in nitric acid, obtaining a concentrate of platinum metals, followed by dissolving the concentrate in Aqua Regia or hydrochloridebuy and further, the classical technological scheme.

In Fig. shows a diagram of the installation for the extraction of rhenium.

Example

Take 750 g of the deactivated reforming catalyst on alumina carrier brand TNK-23 containing 0,296 wt.% platinum and 0.273 wt.% rhenium, fired in an electric furnace in air atmosphere at a temperature of 600°C to stop the gassing (1 hour). The mass of cinder was 735 g, the volume of calcine - 1 l Extraction of rhenium is carried out in the installation shown in Fig. The calcine is loaded into percolator (1)placed in a water bath (2) with water temperature of 80-90°C. In the feed tank (3), mounted on an electric stove (4), pour the water and constantly served in the volume of water chlorine gas, providing the ORP of a solution within 1000-1100 mW. The temperature of the solution vrachebnoe capacity (3) maintained within the range of 80-90°C. Ion-exchange column (5) is filled with resin VP-1P (macroporous weakly basic anion exchange resin on vinylpyridines basis), the amount of resin is 0.5 liter Solution from the supply tank flows into the lower portion and out of the upper part of percolator (1) at a rate of 0.5 l/h Coming out of percolator (1) solution of rhenium acid enters the lower part of the ion-exchange column (5), passes through the resin layer and the top flows in the collector sorbate (6). The sorbate return into the supply tank (3). During control the redox potential of the solution in the supply tank (3) and at the exit of percolator (1) the concentration of rhenium in the solutions coming out of percolator (1) and of the ion-exchange column (5). The results of extraction of rhenium are presented in table 1.

In the sorbate concentration of rhenium does not exceed 1 mg/L. the Calculation shows that the extraction of rhenium catalyst on the resin is approximately 93%.

The concentration of platinum in the catalyst after the extraction of rhenium and drying at 150°C increased slightly due to the mass loss of the original product and is 0,308%.

To set material (catalyst after extracting rhenium) in a quantity sufficient to conduct heat collector to obtain an alloy with a concentration of platinum at least 15%, at the present methodology conduct a series of wimalasiri with sorption of rhenium. The result is 7 kg of the catalyst to what centrala rhenium 0,008%, platinum and 0.3%. To obtain a final concentration of platinum in the alloy is about 15% of the estimated original weight of the collector should be 110, as collector use electrical copper.

Melting is carried out in an induction furnace EAST 0,06 in a graphite crucible. First prepare a mixture composition: catalyst - 7 kg, fluorspar - 0.7 kg, sodium carbonate - 0.35 kg, sodium nitrate - 0.14 kg(1:0,1:0,05:0,02). Next, melt in the crucible 110 g of copper and the molten metal download small portions of the mixture to fill the crucible with the melt 2/3 volume, heated to melt flowable state, turn off oven and leave in for 10 minutes and poured slag, leaving the crucible boundary layer of slag. Then download and melted the next portion of the charge and thus proplast all the prepared mixture. The last portion of the melt is poured into the cast iron mold with metal. After cooling, the metal is separated from the slag. All the resulting slag is crushed to a particle size of -1 mm and test method "with rings on the cone. Metal test method selection shavings from the drilling of the ingot 5 points. The concentration of platinum in the samples determine the methods of x-ray spectrometric analysis.

The result is 135 g of copper-platinum alloy with a concentration of platinum of 15.2% and 7.5 kg of slag with the concentration of platinum 0,0048%, which corresponds to the extraction of p is tiny in the collector 98,7%.

Thus, the use of the invention in the processing of catalysts containing platinum group metals and rhenium, allows you to perform the task, namely to increase the degree of extraction of rhenium, to reduce the consumption of reagents, labor, reduce the duration of processing of raw materials, greatly reduce the volume of solutions requiring disposal.

Table. 1
Name of productTime, hVolume, ml; weight, gAFPConcentration, g/l, %
PtReAl
The catalyst calcined at t°=600°C-750 g-0,2960,273base
The solution at the outlet of percolator (point sample at the moment of passage of the solution specified in the 3rd column of the table)1500671 <0,0020,3010,139
21000565"0,2130,051
31500945"0,3020,065
42000960"--
525001085"--
630001083"0,6260,322
735001099"--
840001101"- -
945001114"0,2420,463
1050001088"--
1155001090"0,085-
1260001104"-0,573
1365001080"0.0430,798
1470001100"--
1575001090"--
16 80001100"0,0010,823
The catalyst after leaching and Re-drying16720-0,3080,02-

1. The method of extraction of rhenium and platinum group metals from spent catalysts on the native oxide of aluminum, including oxidative calcination of catalyst leaching of the resulting calcine aqueous solution of the oxidizing agent with obtaining registertimer solution and the insoluble residue, the sorption of rhenium from registertimer solution by ion-exchange resin, drying the insoluble residue, the subsequent rihtovanie insoluble residue from the flux and melting of the charge on the metal collector, characterized in that the leaching of calcine are percolation leaching with an aqueous solution of an oxidant or mixture of oxidants when the value of the redox potential, 900÷1100 mV, and the temperature of 50-90°C with obtaining insoluble residue and registertimer solution simultaneous sorption of rhenium from registertimer solution on macroporous weakly basic ion-exchange resin in a separate apparatus, followed by desorption Renee allocation of decorate compounds of rhenium metal or a rhenium, and for melting the dried insoluble residue as fluxes using fluorspar, sodium carbonate, sodium nitrate in the ratio (parts by weight) insoluble residue:fluorspar:sodium carbonate:sodium nitrate= 1:0,05÷0,5:0,03÷0,1:0,01÷0,03, a mixture obtained by mixing the insoluble residue from the above fluxes are melting at a temperature of 1200÷1800°C on a metal collector, while melting lead in several stages with the sink after each stage of the formed slag and melting the next portion of the charge on the collector from the previous melting emitting alloy platinum metals with header.

2. The method according to claim 1, characterized in that the leaching is carried out with an aqueous solution of oxidizing agent or a mixture of oxidizing agents selected from the group of chlorine, bromine, hydrogen peroxide, chlorates, perchlorates of alkali metals.

3. The method according to claim 1, characterized in that the leaching use a solution obtained by barbotage gaseous chlorine through the water.

4. The method according to claim 1, wherein the sorbate received after sorption of rhenium from a solution leaching of calcine use on stage percolation leaching of the calcine.

5. The method according to claim 1, characterized in that during the smelting of copper collector.

6. The method according to claim 1, characterized in that during the smelting add borax, know what th or quartz sand to liquefy toxins.

7. The method according to claim 1, characterized in that the melting in several stages eventually produce slag with the concentration of platinum group metals in an amount of not more than 0.005 wt.% and the target alloy of platinum metals with header.

8. The method according to claim 1, characterized in that the ratio of the mass of the collector and the mass of insoluble residue calculated so that the concentration of platinum metal in the reservoir has reached 10÷20%.



 

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1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to sorption hydrometallurgy of uranium and rhenium and can be used to extract rhenium from solutions and pulp. The method of extracting rhenium from uranium-containing solutions includes sorption of rhenium on anions. Before sorption, fulvic acids are added to the solution until concentration thereof in the solution reaches 25-300 mg/l. Rhenium sorption is carried out at solution pH 2.8-3.5. Sorption is carried out on weakly basic and strongly basic anionites.

EFFECT: improved sorption/desorption properties, high cost/performance ratio of the sorption sorption/desorption process of extracting rhenium from a uranium-containing solution.

2 cl, 6 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: method includes precipitation of rhenium sulfides by processing with sulfide-containing precipitator in presence of reducing reagent in form of hydrazine-containing compound and heating reaction mixture. Precipitation of rhenium sulfides in carried out from hydrochloric acid solution, containing iron chloride. First, hydrazine-containing compound in form of hydrazine chloride, hydrazine sulfate or hydrazine hydrate is introduced into solution in amount 2-4 g/l counted for pure hydrazine. After that, reaction mixture is heated at temperature 60-90°C for 20-40 minutes. Then, counted mass of sulfide-containing reagent is introduced and pulp is heated at specified temperature.

EFFECT: reduction of consumption of reducing reagent and high extraction of rhenium into sulfide sediment from hydrochloric solutions, containing iron salts.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method for obtaining metallic rhenium by reduction of ammonium perrhenate involves arrangement of ammonium perrhenate powder in a boat and its reduction by counter current of dry hydrogen with continuous movement of the boat in a tube furnace at the temperature of 300-330°C. Prior to reduction, ammonium perrhenate powder is purged with argon and heated in the tube furnace up to the temperature of 200°C.

EFFECT: method ensures production of rhenium powder that requires no cleaning from impurities, as well as reduction of rhenium powder losses.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method includes dilution of platinum and rhenium by chlorhydric acid, two-staged solution treatment using sodium hydroxide at the first stage with formation of Pt(OH)4 particles and sodium thiosulfate at the second stage with formation of ReS2 particles. Solution treatment with reagents is performed upon availability of cellulose fibres in it with formation of hard products of reaction in the form of composite materials consisting of cellulose fibres with Pt(OH)4 and ReS2 particles immobilised by them at their chemical deposition. Extraction of composite materials from liquid phase at stages is performed using pressure flotation method.

EFFECT: reducing reagents consumption, simplifying process, providing possibility of process performance in continuous mode.

4 cl, 1 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: method involves pulping a concentrate of platinum and rhenium sulphides in aqueous ammonia solution. The pulp is then treated with hydrogen peroxide solution; the reaction mixture is acidified with sulphuric acid, heated and then aged, and the precipitate of platinum compounds is separated from the rhenium solution by filtering the reaction mixture. The pulp is treated with hydrogen peroxide solution at temperature of 25-45°C; the reaction mixture is acidified with sulphuric acid until achieving pH 0.2-2.0 without preliminary separation of the undissolved precipitate. Before filtering, the reaction mixture is further treated with hydrogen peroxide solution.

EFFECT: enabling separation of platinum and rhenium at the step for extracting rhenium from a sulphide concentrate.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method involves roasting of a catalyst, leaching of a roasted product in acid medium and introduction to the obtained pulp of reagents to improve filtration. Then, non-soluble residue is separated from the solution by filtration and metals of platinum group and rhenium are extracted from the solution. Prior to filtration the pulp is treated with water solution of flocculant of cationic type based on polyacrylamide. The obtained reaction mixture is exposed without mixing till solid and liquid phases are separated. Then, clarified part of the solution is separated by decantation and paper pulp in the form of paper wastes in the quantity of 10-20 kg/m3 of the pulp is added to thickened pulp and mixed, and filtration is performed.

EFFECT: improving efficiency of separation of non-soluble residue from the solution; reducing costs for filtration materials.

1 ex

FIELD: metallurgy.

SUBSTANCE: proposed method comprises anodic oxidation of melt in acid electrolyte at application of electric current. Note here that said anodic oxidation is carried out in acid electrolyte containing 150 g/l of H2SO4+50 g/l HCl. Applied direct electric current features density of 250-300 mA/cm2. Application of said current is conducted at 20-40°C.

EFFECT: notable increase in anodic oxidation rate.

3 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: proposed method comprises extracting essential part of rhenium from catalyst by direct contact between catalyst and one or more polar non-acid, in fact, anhydrous organic solvents. In contact with solvent, solution is formed containing said polar non-acid organic solvent and extracted rhenium. Note here that said polar non-acid organic solvent with molar structure that contains one or more atoms of oxygen, nitrogen and/or halogen.

EFFECT: simplified and cheaper process, selectivity of rhenium extraction.

23 cl, 2 tbl, 11 ex

FIELD: process engineering.

SUBSTANCE: invention relates to mining and may be used in applied geochemistry, particularly, to extraction of rhenium. Proposed process includes making colloidal salt solution from specimens of black-shale formations and/or products of their processing, to be minced to grain size not exceeding 0.080 mm, flooding it with water solution heated to boiling point and made up of polyvinyl alcohol with concentration in water solution of 0.05% taken at the ratio of 15:1, mixing prepared suspension, curing it at room temperature for at least 24 h, filtering said suspension to particle size of at least 1200 nm, at rhenium content of at least 0.0001 mg/kg, and extracting rhenium by evaporation to dry residue of colloidal salt solution.

EFFECT: higher accuracy, validity and reliability.

6 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to a method of treatment of copper electrolysis slime floatation concentrate containing precious metals. The method includes leaching and precious metal extraction. Prior to leaching, sintering of floatation concentrate is done in a saline mixture of NaNO3 and NaOH at a ratio 3: 2 at 350-370°C during an hour. The product produced by sintering is subjected to leaching conducted by water at a ratio S:L-1:3 resulting in metal fraction production. The latter is directed to extraction of precious metals through refining and pulp containing a salt fraction and a solution. The pulp is subjected to filtering, wherein the solution is used rot tellurium and selenium extraction, and the salt fraction is used for lead and antimony extraction.

EFFECT: separating of silver, aurum and platinum metals is simplified, silver and aurum loss in water solutions is reduced, and power inputs and labour expenditures are lowered.

1 dwg, 5 ex

FIELD: metallurgy.

SUBSTANCE: process can be used in hydrometallurgy for processing of gold-bearing two-fold hardness concentrates, that is, stock containing gold dispersed in sulphides and organic carbonaceous substance. Prior to feeding the concentrate acid pulp produced by pre-treatment of concentrate with acid into autoclave is cleaned of chlorides. Autoclave leaching is conducted at 225-235°C and terminated at reaching the pulp redox potential in the range of +700 - 730 mV relative to standard hydrogen electrode. For cleaning the pulp of chlorides at filter or at continuous return flow decantation hot condensate or natural water and/or desalinised water may be used. To maintain preset temperature at autoclave leaching cold fresh and/or reused water is fed to every section of autoclave.

EFFECT: higher gold yield.

4 cl, 7 dwg, 3 tbl, 2 ex

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