Method of uranium recovery from ores
SUBSTANCE: said utility invention relates to hydrometallurgical methods of crude ore processing and may be used for sulphuric-acid agitation, heap, and underground leaching of uranium during uranium recovery from ores. The method involves uranium and iron leaching with sulphuric acid solution using ferric iron contained in the ore as the oxidiser; after that, uranium is recovered from the solution to prepare a solution containing ferrous iron, the ferrous iron is regenerated to ferric iron by oxidising to prepare bypass solution, and it is recirculated to the ore leaching. The uranium recovery from the solution is performed by sorption on an anion-exchange substance; after sorption, the solution containing ferric iron is acidified with sulphuric acid before the ferric iron regeneration to ferrous iron in the solution, and regeneration is performed by irradiating it with an accelerated electron flow at an absorbed dose rate of 2.3-3.5kGy/s during 1- 6 minutes.
EFFECT: increase in cost effectiveness, efficiency, and environmental safety of process.
4 cl, 3 dwg, 3 tbl, 2 ex
The invention relates to the hydrometallurgical processing methods of ore and can be used, in particular, sulphuric acid campaign (AB), heap (KB) and underground (PV) leaching of uranium.
Known methods sulphuric acid leaching using as oxidant uranium sulfate ferric /see, for example, Ring R.J. Hydrometallurgia, 1980, 6, 89-101/. Production practice shows that leaching is the most costly redistribution in the overall scheme of processing of uranium ores, therefore, the efficiency of this operation determines the cost of the final product.
According to modern ideas about the electrochemical mechanism of dissolution of uranium dioxide (uraninite, pitchblende and so on) under the action of ferric sulfate to leaching medium was the most effective, all of the iron must be present in the solution in the trivalent form. In the real solution, the presence of other ions in the first ion Fe2+causes a decrease of the speed of the process as a result of competitive adsorption of these ions on the active centers of the surface of the uranium mineral. With a large number of ions of Fe2+in the solution is required to maintain an excess of ions of Fe3+to ensure a satisfactory reaction rate.
On practically oxidation of the bivalent iron ions in sulfuric acid solutions of various known methods, in particular:
- the use of strong oxidizing agents (pyrolusite, chlorates, nitric acid and the like),
molecular oxygen or oxygen:
at elevated temperature and pressure in an autoclave,
at atmospheric pressure, sometimes with catalytic additives (nitrous acid, and others).
All these methods either due to the cost of chemical reagents, which leads to contamination of the solution by impurities (ions), or require the introduction of additional operations, or lack the necessary performance, which ultimately leads to a significant increase in the cost of redistribution.
The known method sulphuric acid agitation leaching of uranium using as oxidant iron compounds contained in the ore. The method consists in splitting the flow of the original slurry into two streams. In the first pre-leached iron with sulfuric acid to neutralize the excess acid pulp of the second stream and oxidize iron oxygen at atmospheric pressure, then again serves acid (if required with the addition of manganese dioxide or ferric). These operations are carried out in a battery of several Pachuca at a temperature of 60-80°for more than 12 h /Larin VK, Litvinenko VG, Sheludchenko VG improving the technology guy is remetalling processing of uranium ores. Mining magazine. 1999, No. 12, 59/. However, due to slow oxidation of iron by oxygen in an acidic environment, this method does not have high efficiency and requires significant energy (compressed air, steam) costs.
The known method sulphuric acid leaching of uranium from ores using ferric iron as an oxidant, including its chemical regeneration. This method involves the preparation of leach solutions containing sulfuric acid and nitrate ions, filtering them through the ore with the translation of hexavalent uranium, ferrous iron and other metals in the final solutions, the extraction of uranium with obtaining uterine fluids and recycling of these solutions on the leaching of ore.
Intensification of the process of leaching of uranium from ores methods KB or PV is achieved through the use of circulating solutions in which ions Fe (II) oxidized to Fe (III), and the latter is already fulfill the role of a direct oxidant of uranium (IV) to uranium (VI). The oxidation of Fe (II) Fe (III) is carried out mainly by oxygen, Bartiromo through the recirculating solution, when the catalytic participation of nitrous acid and nitrogen oxides resulting from the decomposition of nitric acid, which is the source of nitrogen-containing reagent /patent RF №2172792 C1, application 2000106961/02, AVL. 21.03.00, publ. bull. No. 24, 27.08.01. - prototype/.
The disadvantages of this method are:
- the use of several reagents, in particular nitric acid for the formation of an oxidant and as a result, contamination of the production of solutions of nitrate-ions, which reduces the sorption capacity of anion exchange resins for uranium
- the release of toxic nitrogen oxides formed during the preparation of pls, and the need for them to capture with the use of special equipment (vessels with dispersant),
- use as a reagent technical oxygen or less effective oxygen for oxidation of the formed nitrogen oxides and iron (II)
- lack of ecological purity due to the inability to complete the capture of toxic oxides of nitrogen,
the difficulty in the practical implementation and accuracy of maintenance of the set of process parameters.
The technical result of the proposed method is to improve the economy, efficiency and environmental friendliness of the process of leaching of uranium from ores with sulphuric acid is used as an oxidant iron ore.
This result is achieved in that in the method of extraction of uranium from ores underground methods or heap and agitation leaching with sulfuric acid using as the oxidant Fe (III), contained in the ore, including the leaching of uranium and iron, the extraction of uranium sorption on the resin, the receipt of the circulating solution, the regeneration of the oxidation of Fe2+to Fe3+in this solution and its recycling to the leaching of the ore, and circulating a solution containing divalent iron, after doreplace sulfuric acid is irradiated with a flux of high-energy electrons when the absorbed dose rate is 2.3-3.5 kGy/C for 1-6 minutes Working solution heap or underground leaching, containing 0.5-5 g/l Fe2+before irradiation is acidified with sulfuric acid, going to the leaching of uranium to a concentration of 5-10 g/L. Clarified working solution agitation leaching obtained by thickening or hydrocycloning discharged slurry containing 5-15 g/l Fe2+before irradiation acidified part of sulphuric acid required for leaching the ore to a concentration of 10-20 g/L.
We developed a "reagentless" radiation-chemical technology of regeneration of the oxidant. The transfer of ions of bivalent iron to trivalent form without the participation of chemicals and forced heating is achieved by irradiation of the solution with a stream of accelerated electrons. It is established that short-term (a few minutes) exposure model sulfate solutions of ferric sulfate which allows almost completely oxidize ferrous ions to the trivalent state in a wide range (1-10 g/l) concentrations of iron and sulfuric acid. Developed radiation-chemical technology "reagentless" regeneration effective oxidant for use in the processes KB and PV, and agitation leaching of uranium with sulfuric acid.
Radiation-chemical technology is currently one of the most progressive. The production of linear accelerators industrial type developed by the enterprise Agency for AE of the Russian Federation (St. Petersburg) and at the plant of the Institute of nuclear physics. Of nuclear physics, SB RAS in Novosibirsk. These units are widely used for work around the clock in environmental technologies for industrial wastewater treatment, effluent of textile production and cattle-breeding complexes, drinking water, toxic waste, etc. /XI International conference on application of accelerators in industry and medicine (ICAA'05)/ St Petersburg, October 2005/.
Thus, the efficiency, effectiveness and environmental friendliness of the process sulfuric acid extraction of uranium from ores methods of propaganda, heap and underground leaching using as oxidant ferric ions is achieved by circulation of the circulating solution after sorption of uranium extraction and regeneration of the oxidizing agent by the irradiation of these solutions stream of accelerated electrons and return the attachment regenerated oxidant in the leaching of uranium.
Example 1. The degree of oxidation of ferrous iron on the duration of exposure. Main technological parameters of the process at a given mode of exposure is the concentration of iron ions and sulfuric acid. The influence of these parameters on the degree of oxidation of the bivalent iron ions was studied in the range of concentrations of Fe2+1-5 and acid 2-5 g/l, i.e. with respect to the conditions of the processes of ROS and KB uranium from ores ( see table 1).
The degree of oxidation of ferrous iron was calculated as the change in the concentration of bivalent iron ions in irradiated and unirradiated solutions:
The sulfuric acid concentration was determined by potentiometric titration, the concentration of iron trigonometricas (sulfosalicylic acid) before and after irradiation.
Researched solutions in open plastic jars with a capacity of 100 ml were placed on a rotating table (10 rpm) of the working chamber, which are regulated relative to the beam so that the beam hit the center of the irradiated sample.
The experiments were carried out under the following energy parameters:
- kinetic energy 7 MeV,
- the average current of 25 μa,
the current density - 32 µa/cm2.
The power of the absorbed dose was determined from the known is tion ratio
where η - coefficient taking into account the proportion of absorbed in the sample beam of electrons to the water solution of 0.95, I is the average current of accelerated electrons, E is the kinetic energy of the electrons, m is the mass of the solution.
Solutions after irradiation remained transparent. Exposure to acidified (2.4 g/l, pH 1,6) sulfate solution ferrous iron concentration ˜0.8 g/l when the absorbed dose rate of 3.46 kGy/s in less than a minute provides a high degree of oxidation (˜87%). The almost complete oxidation of iron is achieved in just 1.5-3 min (see table 1). By increasing the concentration of ions of bivalent iron to 5.2 g/l high degree of iron oxidation (at 92%) is achieved for 6 min at lower absorbed dose rate to 2.3 kGy/s, i.e. almost in half.
Example 2. The degree of oxidation of ferrous iron concentration of iron ions and sulfuric acid in the irradiated solution.
The influence of these parameters on the degree of oxidation of the bivalent iron ions in the irradiated solutions was studied at concentrations of Fe2+1-11 and acid in the range of 2-16 g/l (see table 2).
As can be seen from table 2, the degree of iron oxidation strongly depends on the initial concentration of ferrous iron and sulfuric acid in the solution. But when the concentration of iron (II) 1 g/l degree ocil the deposits reaches 100%, regardless of the acidity of a solution.
With increasing concentration of ferrous iron in the original solution from 1 to ˜11 g/l (see table 2) found a significant effect of the concentration of sulphuric acid on the oxidation of ferrous iron in the exposure.
With the increase of iron concentration in the source solution to 2.5 g/l (see No. 5-8 table 2) and the acid concentration of 10-15 g/l oxidation of ferrous iron is 100%. At lower acid concentrations (up to 2-5 g/l) oxidation state of iron is somewhat reduced (up to 80-88 %).
The degree of oxidation of the bivalent iron ions on the duration of irradiation (τ) at different absorbed dose rate (DM)
|No. op. PCT||τ, min||DM, kGy/s||The characteristic solution||The oxidation state of Fe %|
|Concentration, g/l||O-RR, mV|
|*) the concentration is not detected.|
To obtain the same result by increasing the iron concentration to the ˜5 g/l concentration sour the s should be above 10 g/L. When the iron concentration in the initial solution, more than 10 g/l and high acid concentration (˜16 g/l) oxidation is ˜54 %. The increased duration of exposure to 6 min at a dose rate of 3.5 kGy/s increases the degree of iron oxidation up to 70-80%.
The degree of oxidation of iron (II) concentration of iron and sulfuric acid when absorbed dose rate of 2.3 kGy/s and duration of exposure 3 min
|No. op. PCT||The original solution||The irradiated solution||The oxidation state of Fe %|
|Concentration, g/l||O-RR, mV||Concentration, g/l||O-RR, mV|
|1||0,2||1,0||2,5||360||1,2||the concentration is||2,3||600||100|
the concentration is
|9||0,9||of 5.4||2,2||355||3,7*||2,4||pH 2.0||435||51,9|
|* - fell precipitate of iron hydroxide (III)|
** the exposure time of 6 min with DM=a 3.5 kGy/s
The oxidation of bivalent iron ions is accompanied by a corresponding increase in the magnitude of About-EAP, reaching values 500-675 mV at 100%oxidation. At pH˜2 due to the lack of free acid in the solution p is oshodi termogidrodinamicheskoe decomposition minor part of the ions of ferric sulfate and education Zola hydroxide. Results the dependence of the oxidation rate (N, %) iron (II) concentration of sulfuric acid (g/l) and iron (II) is illustrated by figure 1, where the concentration of iron (II) in the original solution: the series 1-1 g/l, the range of 2-2,5 g/l, range 3-5,3 g/l, range 4-10,6 g/l
These dependencies allow us to determine the completeness of the oxidation of bivalent iron ions in relation to current solutions process sulphuric acid leaching of uranium.
In table 3 are examples of compositions of the solutions obtained after leaching of uranium and iron in various ways (productive solution and working solution after regeneration of the oxidant by acidification with sulfuric acid and irradiation stream of accelerated electrons.
|Method of leaching||Productive solution||Working solution|
|concentration, g/l||O-RR, mV||concentration, g/l||O-RR, mV|
The maximum degree of extraction of uranium in solution at this pH occurs when the value Of-EAP solution at the level of 500-600 mV, i.e. when the minimum concentration of ions of bivalent iron.
Based on the data available process flow diagram of the extraction of uranium from ore with sulfuric acid at underground, heap (figure 2) and agitation (figure 3) leaching.
Productive solutions after KB or ISL uranium sulfuric acid using as oxidant iron contained in the ore, proceed on the sorption of uranium. The mother liquor, in which the iron is predominantly in the reduced form, i.e. in the form of divalent ions is working and after the addition of acid required for the leaching of uranium, and the regeneration of the oxidant returns what is in the leaching operation. The operation of regeneration, i.e. radiation-chemical oxidation of the bivalent iron ions to the trivalent state radiolysis products, is carried out by irradiation of the solution with a stream of high-energy electrons produced by the linear accelerator.
When the agitation leaching scheme (figure 3) is characterized by the fact that on the sorption of uranium enters the pulp, and the allocation of working solution (top discharge) is carried out by condensation or gidrotsiklonirovaniya (or filtering) the acidic pulp. The thickened slurry of (floor drain) goes to dump. In this case, the regeneration is carried out at pH<2, which in operation serves a small portion of the acid from entering the leaching of uranium.
1. The method of extraction of uranium from ores, including leaching of uranium and iron sulfuric acid solution using as oxidant ferric iron contained in the ore, extraction of uranium from the solution to obtain a solution containing divalent iron, regeneration of divalent iron to trivalent oxidation with obtaining a working solution and its recycling to the leaching of the ore, characterized in that the extraction of uranium from a solution of lead adsorption on the anion exchange resin obtained after adsorption solution containing divalent iron, before regeneration it divalent same is ESA to trivalent acidified with sulfuric acid and the regeneration of lead exposure to a stream of accelerated electrons with the power absorbed dose of 2.3 to 3.5 kGy/C for 1-6 minutes
2. The method according to claim 1 characterized in that the leaching methods are underground, heap or agitation leaching.
3. The method according to claim 2, characterized in that the circulating solution at a compact or underground leaching, containing 0.5-5 g/l ferrous iron, before irradiation is acidified with sulfuric acid to a concentration of 5-10 g/L.
4. The method according to claim 2, characterized in that the circulating solution with agitation leaching, containing 5-15 g/l ferrous iron, before irradiation is acidified with sulfuric acid to a concentration of 10-20 g/L.
FIELD: production methods.
SUBSTANCE: method of monazite recycling includes the milling of the monazite, processing during the heating by substance of hydroxide of alkaline metal, generating of the salt of phosphor acid, dilution of the filter cake in the mineral acid with the following abstraction of rare earth elements (REE), thorium and uranium. Processing is done by substance of kalium hydroxide = 1:1.0-1.5 with obtaining the substance of triallyl phosphate kalium and precipitation, containing the hydroxide of thorium, uranium, REE, notopened monocyte and empty land, which is processing by azotic acid, extending the nitrate REE in the substance. It is importuned from the substance the carbonates of REE by kalium carbonate. The rest of cake is processing by the substance of kalium carbonate with translating uranium into the substance and following importuning as dihydroxide dioxuranium and the final processing of the cake by the substance of azotic acid with generating thorium into the substance by importuning of thorium by the substance of kalium carbonate. The mother water from the importuning of REE, thorium and uranium and three kalium phosphate is distained to the producing of manuring. The substance of three kalium phosphate and hydroxide kalium is vapored , and it is separated crystal three kalium phosphate, and hydroxide kalium is distained to the head of process. The rest after processing by azotic acid not opened monocyte is distained to the head of process.
EFFECT: simplifying of the process and more effective using of all components of monoyte.
6 cl, 1 ex
FIELD: technology of processing uranium-and fluorine-containing wastes.
SUBSTANCE: proposed method includes preparation of solutions from wastes, concentration of solutions by sedimentation of uranium followed by dissolving of sediments in nitric acid, extraction conversion of concentrated solutions with the use of tributyl phosphate in hydrocarbon thinner and sedimentation of ammonium polyuranates from re-extracts thus obtained. Sedimentation of uranium at stage of concentration is performed with the use of sodium hydroxide at pH= 9-10 and temperature of 60-90C. Proposed method enhances purification of uranium from fluorine due to enhanced sedimentation and filtration properties of sediments at concentration stage. Content of admixtures in triuranium octa-oxide powders obtained from re-extracts by sedimentation of ammonium polyuranates and subsequent calcination does not exceed specified norms.
EFFECT: enhanced efficiency.
1 dwg, 2 tbl, 1 ex
FIELD: processing uranium-containing products formed at extraction of uranium from solutions followed by re-extraction by means of ammonium carbonates; extraction of uranium and accompanying valid components from ores.
SUBSTANCE: proposed method includes thermal dissociation at sedimentation of uranium, entrapping of ammonia and carbon dioxide from waste gases. Thermal dissociation of uranium-containing ammonium carbonate solutions is performed at temperature of 70-85°C to pH= 6.5-5.9 at simultaneous blowing of gases by air; solutions obtained after thermal dissociation are separated from uranium-containing sediment and accompanying valid components, molybdenum for example are extracted from them.
EFFECT: enhanced efficiency of utilization of ammonia and carbon dioxide; high degree of separation of uranium and admixtures; extraction of accompanying valid components, molybdenum for example.
2 cl, 1 tbl, 2 ex
FIELD: hydraulic metallurgy.
SUBSTANCE: method comprises extracting saturated ionite from the pulp, washing it with water, desorbing uranium, washing desorbed ionite to decrease acidity, separating by wet screening into 1.0±0.2-mm size, extracting silicon from the under-screen product, and discharging it and above-screen product to the uranium sorption.
EFFECT: reduced ionite consumption.
1 cl, 1tbl
SUBSTANCE: extractant has bi-phosphorus acid and additionally has tri-phosphate with relation of said components (0,5-1,25):1. Method for producing extractant includes adding to 2-ethylhexanole of chlorine oxide of phosphorus with their relation (4,5-5,1):2,0, and with parameters determined by reaching fullness of passing of reaction, after that reaction mixture is exposed until full removal of formed chlorine hydrogen, then to received mixture 1 mole of water is added, mixture is exposed to full hydrolysis. Then mixture is washed ad water layer is separated from organic remainder, containing said bi-phosphoric acid and tri-phosphate.
EFFECT: higher efficiency.
2 cl, 1 dwg, 2 tbl, 4 ex
FIELD: uranium technologies.
SUBSTANCE: method comprises sorption of uranium on low-basicity anionites, desorption of uranium, and recovery of finished product. In particular, uranium-saturated low-basicity anionite is converted into OH- form and uranium into soluble stable complex [UO2(CO3)3]-4 by treating sorbents with alkali metal and ammonium carbonate solutions.
EFFECT: achieved complete desorption of uranium and simultaneously sorbent is freed from poisons and other sorption components.
FIELD: chemical technology; deactivation and decontamination of radioactive industrial products and/or wastes.
SUBSTANCE: proposed method designed for deactivation and decontamination of radioactive industrial products and/or production wastes incorporating Th-232 and its daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Al, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like and that ensures high degree of coprecipitation of natural radionuclides of filtrates, confining of radioactive metals, and their conversion to environmentally safe form (non-dusting water-insoluble solid state) includes dissolution of wastes, their treatment with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9-10 in the amount of 120-150% of that stoichiometrically required for precipitation of total content of metal oxyhydrate; then pulp is filtered and barium chloride is injected in filtrate in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp and pre-dissolved in sulfuric acid of chlorine compressors spent 5-20 times in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2. Then lime milk is added up to pH = 11 - 12 and acid chloride wash effluents of equipment and production floors are alternately introduced in sulfate pulp formed in the process at pulp-to-effluents ratio of 1 : (2-3) to pH = 6.5 - 8.5. Filtrate pulp produced in this way is filtered, decontaminated solution is discharged to sewerage system, sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization, inert filler and 0.5 - 2 parts by weight of calcium sulfate are introduced in pasty mixture while continuously stirring them. Compound obtained in the process is placed in molds, held therein at temperature of 20 - 50 oC for 12 - 36 h, and compacted in blocks whose surfaces are treated with water-repelling material.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes.
8 cl, 1 dwg, 1 ex
FIELD: chemical technology; recovery of deactivated and decontaminated radioactive industrial wastes.
SUBSTANCE: proposed method that can be used for deactivating and decontaminating industrial radioactive wastes incorporating Tb-232 and their daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Sl, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like includes dissolution of wastes, treatment of solutions or pulps with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9 - 10 in the amount of 120-150% of total content of metal oxyhydrates stoichiometrically required for precipitation, pulp is filtered, and barium chloride in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp, as well as pre-diluted sulfuric acid spent 5 - 20 times in chlorine compressors in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2 are introduced in filtrate. Alternately introduced in sulfate pulp formed in the process are lime milk to pH = 11 - 12, then acid chloride wash effluents from equipment and industrial flats at pulp-to-effluents ratio of 1 : (2 - 3) to pH = 6.5 - 8.5, and pulp obtained is filtered. Decontaminated solution is discharged to sewerage system and sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization process; then 35 - 45 mass percent of inert filler, 10 - 20 mass percent of magnesium oxide, and 15 -m 25 mass percent of magnesium chloride are introduced in pasty mixture formed in the process while continuously stirring ingredients. Compound obtained is subjected to heat treatment at temperature of 80 - 120 oC and compressed by applying pressure of 60 to 80 at.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes due to enhanced coprecipitation of natural radionuclides.
7 c, 1 ex
FIELD: rare, dispersed and radioactive metal metallurgy, in particular hydrometallurgy.
SUBSTANCE: invention relates to method for reprocessing of polymetal, multicomponent, thorium-containing radwastes, formed when reprocessing of various mineral, containing rare-earth elements, Nb, Ta, To, V, Zr, Hf, W, U, etc. Method includes treatment of solution and/or slurry with alkaline agent; introducing of sulfate-containing inorganic compound solution and barium chloride; treatment of obtained hydrate-sulfate slurry with iron chloride-containing solution, and separation of radioactive precipitate from solution by filtration. As alkali agent magnesia milk containing 50-200 g/dm2 of MgO is used; treatment is carried out up to pH 8-10; sodium sulfate in amount of 6-9 g Na2SO4/dm2 is introduced as solution of sulfate-containing inorganic compound; barium chloride solution is introduced in slurry in amount of 1.5-3 g BaCl2/dm2. Hydrate-sulfate slurry is treated with solution and/or slurry containing 0.8-16 Fe3+/dm2 (as referred to startingsolution) of iron chloride, followed by treatment with high molecular flocculating agent and holding without agitation for 0.5-2 h. Radioactive precipitate is separated from mother liquor, washed with water in volume ratio of 0.5-2:1; then washed with sodium chloride-containing solution and/or slurry in volume ratio of 0.5-2:1; radioactive precipitate is removed from filter and mixed with mineral oxides in amount of 0.5-0.8 kg MgO to 1 kg of precipitate. Formed pasty composition is fed in forms and/or lingots and presses with simultaneous heating up to 80-1200C.
EFFECT: filtrate with reduced radioactivity due to increased codeposition coefficient of natural Th-232-group radioactive nuclide, in particular Ra-224 and Ra-228, with radioactive precipitates.
10 cl, 1 ex
SUBSTANCE: method for processing sphene concentrate implies disintegration of concentrate, hot decomposition thereof with diluted sulphuric acid to dissolve titanium and to precipitate calcium and silicon, isolation of titanium-containing solution, treatment thereof with phosphoric acid resulting in titanium phosphate precipitation, and treatment of calcium-silicon precipitate. Concentrate is disintegrated down to size of not more than 10 mcm. Prior to treatment of titanium-containing solution with phosphoric acid, ammonium sulphate is added to the solution in amount providing for precipitation of not more than 85% of titanium, resulting precipitate is isolated and washed with saturated solution of ammonium sulphate, which results in titanium binary salt. The solution remaining after the precipitate isolation is treated with 50-70% phosphoric acid, and titanium phosphate precipitate is washed with diluted phosphoric acid.
EFFECT: increase in degree of titanium recovery from sphene concentrate and degree of sphene concentrate utilisation.
5 cl, 4 ex
FIELD: mining industry.
SUBSTANCE: invention can be used in technology of preparing titanium-containing pigments from sphene concentrate. Processing process consists in treatment of sphene concentrate with sulfuric acid solution on boiling thereby transferring titanium into liquid phase followed by isolating it into precipitate, separating precipitate, washing and calcining it to form titanium-containing pigment. Treatment is first conducted with sulfuric acid solution having concentration 850-900 g/L preheated to boiling temperature, wherein sphene concentrate micronized to the size less than 15-20 μm is subjected to treatment and introduced by small portions during 30-60 min. When initial concentration of acid solution falls to 600-650 g/L, treatment is conducted for 4-6 h under boiling conditions. Further, treatment is conducted for 1 h at 80-90°C after reduction of initial concentration of acid to 450-500 g/L to produce solution containing titanium.
EFFECT: enabled preparation of transparent, well filtering, and containing no silicic acid titanium-containing solutions suitable for preparation of pearly pigment, integrated utilization of raw material, and reduced loss of titanium dioxide.
3 cl, 7 ex
FIELD: sulfate method of production of titanium dioxide from titanium-containing material.
SUBSTANCE: proposed method includes leaching-out of titanium-containing material by sulfuric acid solution, thus obtaining lye containing titanyl sulfate, separation of titanyl sulfate from lye, hydrolysis of titanyl sulfate for forming solid phase containing hydrated titanium oxides followed by roasting the solid phase obtained at the hydrolysis stage. Proposed method includes additional leaching-out stage for leaching-out of solid phase remaining after leaching-out of initial titanium-containing material by means of solution containing sulfuric acid.
EFFECT: enhanced efficiency of process.
24 cl, 2 dwg, 9 tbl, 13 ex
FIELD: industrial inorganic synthesis.
SUBSTANCE: invention relates to a sulfate process for titanium dioxide production from titanium-containing material. Process comprises leaching starting material to produce leaching lye containing acidic solution of titanyl sulfate, which is separated from the lye and then hydrolyzed to form hydrated titanium oxides further fired to produce desired titanium dioxide. Hydrolysis step is properly controlled to form hydrated titanium oxides with desired particle size distribution.
EFFECT: enhanced commercial process efficiency.
29 cl, 2 dwg, 9 tbl, 13 ex
FIELD: sulfate method of production of titanium dioxide from titanium-containing material.
SUBSTANCE: proposed method includes leaching-out of titanium-containing materials with sulfuric acid solution for obtaining lye, deposition of ferrous sulfate from lye, extraction of titanyl sulfate from lye by means of solvent, hydrolysis of extracted titanyl sulfate followed by roasting of solid phase obtained at hydrolysis stage. At least part of raffinate from extraction stage is used as part of leaching solution at initial leaching-out stage.
EFFECT: high degree of purity of titanium dioxide; reduced amount of acid; reduced power requirements.
20 cl, 2 dwg, 9 tbl, 13 ex
FIELD: non-ferrous metallurgy; methods of extraction of vanadium out of the highly concentrated lime slag.
SUBSTANCE: the invention is pertaining to the field of non-ferrous metallurgy, in particular, to vanadium metallurgy, namely to the method of extraction of vanadium out of the highly concentrated lime slag providing for the wet milling of the highly concentrated lime slag with production of the pulp, treatment of the slag pulp with the sulfuric acid and its oxidizing burning, the sulfuric-acidic leaching of the burning product with the subsequent settling of vanadium from solution by hydrolysis. The technical result of the invention is the increased output of the extracted vanadium as the commercial product, and also improvement of the production process indices at reprocessing of the highly concentrated lime slag. For gaining the technical result the milled slag pulp is treated with the concentrated sulfuric acid taken in the amount of 30-35 % to the mass of the slag. The oxidizing burning is conducted at the temperature of 700-950°С. The product of the burning is subjected to leaching in the weak-acid solution of the sulfuric acid and conduct vanadium settling from the produced solution.
EFFECT: the invention ensures the increased output of the extracted vanadium as the commercial product, the improved production process indices at reprocessing of the highly concentrated lime slag.
1 tbl, 8 ex
FIELD: hydrometallurgy, chemical technology.
SUBSTANCE: invention relates to the leaching reaction of manganese from manganese-oxide ores. Solution used for leaching manganese-oxide ores contains the following components, wt.-%: sulfuric acid, 19.0-20.0; ethylene glycol, 30.0-80.0, and water, the balance. Using the proposed solution that is stable in strongly acid media and at high temperatures (200°C) provides enhancing the selective rate of dissolving manganese oxides from depleted manganese-oxide ores. Invention provides the complete dissolving manganese oxides based on surface reduction of manganese dioxide.
EFFECT: improved and valuable chemical properties of solution.
1 dwg, 2 ex
FIELD: rare-earth element technology.
SUBSTANCE: invention relates to technology of recovering rare-earth elements from phosphogypsum obtained from processing of apatite concentrate into mineral fertilizers. Phosphogypsum is treated with 22-30% sulfuric acid solution at liquids-to-solids ratio 1.8-2.2 to recover rare-earth elements and sodium into solution. Insoluble precipitate is separated and degree of oversaturation of solution regarding rare-earth elements is increased by means of providing sodium concentration 0.4-1.2 g/L, after which crystallization of rare-earth element concentrate is allowed to proceed and concentrate is then separated from mother liquor. Treatment duration is 20-30 min to prevent spontaneous crystallization of rare-earth element concentrate in solution before insoluble precipitate is separated. Content of sodium in solution is controlled by adding a sodium salt thereto, preferably sodium sulfate or sodium carbonate. Degree of recovery of rare-earth elements from phosphogypsum into concentrate achieves 71.4%.
EFFECT: increased degree of rare-earth element recovery and simplified procedure due to eliminated operation of dilution of recycle sulfuric acid solutions and shortened sulfuric acid treatment duration by a factor of 2-3.
2 cl, 1 tbl, 3 ex
FIELD: rare metal technology.
SUBSTANCE: method comprises leaching of initial material in sulfuric acid aqueous solution to produce solution and solid precipitate, said leaching conducted in presence of sulfate of metal having higher positive oxidation potential than that of aluminum. Solution obtained is treated with complexing ampholite with benzyliminodiacetate groups and thus recovered gallium is then concentrated.
EFFECT: increased degree of gallium recovery into solution and reduced consumption of sulfuric acid.
4 cl, 3 tbl, 3 ex
SUBSTANCE: invention relates to method for enrichment of slurries from nickel electrolysis and other products containing platinum metals, gold and silver as well as to method for reprocessing of products obtained by processing of sulfide copper-nickel ores. Claimed method includes slurry autoclave oxidative leaching followed by flotation. Leaching is carried out at 108-110°C and oxygen partial pressure of 0.4-1.0 MPa.
EFFECT: concentrate with low content of non-ferrous metals.
FIELD: hydrometallurgy of non-iron, rare and noble metals.
SUBSTANCE: invention relates to reprocessing of metal sulfide-containing ores, products and waste of ore concentrating and metallurgy industry. Method includes leaching in sulfuric acid solution with concentration of 1.8-35 g/dm3 at 0-1500C in presence of iron(III) ions with concentration more than 1 g/dm3 and iron regeneration using element compounds having built-in voltage when transition from highest valence to lowest one higher the same of iron. Compounds are added into solution when increasing iron(II) ion concentration. Method is useful in leaching by bawl, percolation, heap, and underground processes, as well as in metal recovering into solution, development of rare and noble metals, impregnated in metal sulfides. Invention affords the ability to reduce power requirement, increase effectiveness of equipment utilization, and decrease reagent consumption.
EFFECT: high degree sulfide decomposition with increased metal recovery and reduced leaching time.
8 cl, 3 ex