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Method of treating natural phosphate for extraction of rare-earth elements Invention relates to extraction of rare-earth elements from a natural phosphate. The method includes sulphuric acid decomposition of the phosphate into mineral fertilisers to obtain phosphogypsum. Further, the method includes separating the phosphogypsum and sulphuric acid decomposition of the phosphogypsum by successively treating multiple portions of phosphogypsum with one sulphuric acid solution. Further, the method includes separating the acid-resistant part of phosphogypsum, crystallising the rare-earth element concentrate, separating the rare-earth element concentrate by filtering to obtain a sulphuric acid filtrate and processing the rare-earth element concentrate. The separated acid-resistant part of phosphogypsum is treated with ammonia and carbon dioxide gas to obtain a calcium carbonate precipitate and ammonium sulphate solution. The calcium carbonate is separated, the ammonium sulphate is heat treated to obtain ammonium bisulphate and ammonia, which is returned for treating the acid-resistant part of phosphogypsum, and sulphuric acid solution, which is fed for decomposing the phosphate, is obtained from the obtained ammonium bisulphate and sulphuric acid filtrate with addition of sulphuric acid. |
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Method of leaching of valuable components and rare-earth elements from cinder material Invention relates to biohydrometallurgy, in particular to biotechnology of extraction of valuable components and rare-earth elements from coal combustion products - cinder material. The method of leaching of valuable components and rare-earth elements from cinder material includes preparation of a pulp in the bioreactor with the ratio of solid vs liquid phases (S:L) = 1:5, and the ratio of cinder material vs. element sulphur is 10-20:1. Then pH level of the pulp of concentrated sulphuric acid is brought to the values 2.0-3.0, nutritious salts are added to the pulp and the pulp is inoculated by adding of 10% of the culture liquid containing cenosis of acidophile chemolithotrophic microorganisms. Then the process of biooxidation of element sulphur by microorganisms is performed with mixing the pulp, aeration by air and at the temperature 44-46°C, followed by formation of sulphuric acid, decrease of pH level and leaching of valuable components and rare-earth elements. |
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Invention relates to field of recycling phosphate raw material, in particular to methods of extracting rare earth metals from apatite concentrate in nitric acid recycling of concentrate into complex fertilisers and can be used in chemical and accompanying fields of industry. Method of extracting rare earth metals includes sorption of rate earth metals from nitrophosphate solution by contact of sorbent material with nitrophosphate solution, with application of polyfunctional cationite with complex-forming ion-exchanges used as sorbent material, separation of saturated cationite from solution, washing and desorption of rare earth elements with desorbing solution, which contains ammonium nitrate and nitric acids, processing with desorbing solution, containing ammonium nitrate and nitric acid, processing obtained desorbant without thorium with ammonia-containing precipitator in one stage with sedimentation of rare earth when pH=2-4 is reached and separation of sediment of collective rare earth concentrate by filtration. |
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Method of phosphite processing Method includes water processing, leaching of phosphate with sulphuric acid solution with concentration 3-6 wt % with conversion of REE, calcium and thorium into leaching solution and with obtaining gypsum product, extraction of REE, calcium and thorium from leaching solution by sorption with sulphoxide cationite. Leaching is carried out with sulphuric acid solution and L:S not less than 1.4:1. Sorption of REE, calcium and thorium is realised in stages. At first stage leaching solution is passed through cationite before beginning of REE breakthrough into forming primary depleted sulphuric acid solution. After that, desorption of calcium and thorium from saturated cationite with primary depleted sulphuric acid solution is carried out with obtaining primary calcium-thorium-containing strippant. At second stage remaining leaching solution is passed through cationite before REE breakthrough into secondary depleted sulphuric acid solution, which is applied for calcium and thorium desorption with obtaining secondary calcium-thorium-containing strippant. Then desorption of REE with solution of ammonium nitrate and precipitation of REE from strippant at pH 7.35-7.5 are realised. |
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Method of processing of ferrous rare-earth phosphatic ores Ferrous ore is subjected to intensive machining to destruct mineral aggregates and for deep opening of the phosphate minerals of rare-earth minerals, yttrium and thorium, then ore is leached by solutions of the nitric acid at 180-240°C. Under such conditions the phosphate minerals of the listed elements completely decompose and go into solution, and escaping phosphoric acid is adsorbed on iron oxides (3+) with generation of the insoluble compounds, thus ensuring creation of the dephosphorized nitrate solutions suitable for extraction processing. Increased temperature ensures hydrolysis of the ferrous nitrates even in strongly acidic (nitric) solutions. |
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Method of processing monazite concentrate Invention relates to rare and radioactive element technologies and can be used to obtain concentrates of rare and rare-earth elements from monazite. The method of processing monazite concentrate includes treating the feed stock with a mixture of sulphuric acid and ammonium fluoride at 200-230°C for 30-40 min, purifying the obtained product from phosphate and fluoride products by sublimation, water leaching sulphates of rare-earth elements, neutralising the solution with barium chloride, selectively separating the thorium, uranium, iron and rare-earth product, wherein separation of the rare-earth product is carried out through a step of precipitating double salts of rare-earth elements with ammonium sulphate, followed by conversion into nitrates of rare-earth elements through a calcination step, dissolving in nitric acid and solvent refining from thorium impurities. |
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Method of extracting samarium (iii) cations from water phases In the process of flotation-extraction of samarium (III) as the organic phase applied is isooctyl alcohol, and as a collector - SAS of an anion type sodium dodecylsulphate in the concentration, corresponding to the reaction stoichiometry: Sm+3+3NaDS=Sm(DS)3+3Na+, where Sm+3 is the samarium (III) cation, DS- is dodecylsulphate-ion. Flotation-extraction is realised at pH=7.5-8.5 and a ratio of organic and water phase being 1/20-1/40. |
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Method of extracting cations eu+3 from water-salt solutions Invention relates to a method of extracting europium (III) cations from a weak or technogenic raw material by liquid extraction. The method of extracting the europium (III) cations includes liquid extraction from water-salt solutions with the application of isooctyl alcohol as an extragent. Before extraction into the water-salt solution added is SAS of an anion type, which is represented by sodium dodecylsulphate, with the formation of europium dodecylsulphate solvate for its transportation through a water and organic phase. Sodium dodecylsulphate is added into the solution in a concentration, corresponding to stoichiometry of a reaction: Eu+3+3C12H25OSO3Na=Eu[C12H25OSO3]3+3Na+, where Eu+3 is the europium cation, C12H25OSO3Na is sodium dodecylsulphate, Eu[C12H25OSO3]3 is the solvate. Liquid extraction is realised at pH=3.0-6.0. |
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Complex processing method of residues of domanic formations Invention relates to a processing method of Domanic formations. The method involves agitation neutralisation - decarbonation by treatment with pulp of crushed ore or by a neutraliser of a hardened solution cleaned from aluminium so that a productive solution and decarbonated cake is obtained. Then, a clay product is leached from decarbonated cake in the form of nepheline with the hardened solution so that pulp sulphate is obtained. After that, autoclave oxidation leaching of uranium, vanadium, molybdenum and rare-earth metals is performed from a solid phase of pulp sulphate in presence of substances that oxidise vanadium selectively so that a hardened solution, which contains aluminium, vanadium, uranium, molybdenum and rare-earth metals, and insoluble residue is obtained. Gold and platinum is extracted from the insoluble residue. Potassium aluminium sulphate alum is extracted from the hardened solution. Uranium and molybdenum and vanadium and rare-earth metals are extracted from the productive solution. |
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Method of extracting rare earth elements from extraction phosphoric acid Invention relates to a method of extracting rare earth elements (REE) from extraction phosphoric acid (EFA). The method includes the application of an anionite of a phosphate-mixed form in a cyclic process of sorption-desorption. Desorption at all, except the last, stages-cycles is carried out until a ratio of initial (C0) and final (C) concentrations of the acid corresponds to the condition 0.25≤C/C0≤0.75, and at the last one until the concentration of desorbed phosphoric acid is not more than 0.15 mol/l. Passing of EFA through a column with an anionite is carried out at each stage of the cycle from bottom to top to a breakthrough, corresponding to a relative concentration, corresponding to the condition 0.25≤C/C0≤0.75. An obtained enriched in REE solution is directed to the extraction of a solid REE concentrate. Desorption at each stage of the cycle is carried out with diluted phosphoric acid with obtaining at all, except the last one, stages-cycles of a purified phosphoric acid desorbate and a last stage-cycle desorbate - with a relative concentration of phosphoric acid, corresponding to the condition 0.25≤C/C0≤0.75, and with the concentration lower than 0.25 mol/l. The latter is returned to the desorption stage. |
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Method for acid treatment of red mud Method includes leaching using water-soluble fatty carboxylic acids with less than 3 carbon atoms per molecule as the leaching agent. The desired products to be extracted are then separated from the obtained solution. Leaching is carried out with addition of red mud in portions while controlling pH and ceasing addition of the red mud upon achieving pH 2.3-3.8. After leaching, the solution is held at a given leaching temperature for at least one hour. |
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Method of sulphuric acid decomposition of rem-containing phosphate raw material Invention relates to method of obtaining compounds of rare earth metals (REM) in complex processing of phosphate raw material, in particular apatites. Claimed is method of sulphuric acid decomposition of REM-containing phosphate raw material with concentration of REM in phosphogypsum. Method includes addition of sodium salt, potassium salt or their mixture. Sodium salts are added in amount 0.25-5.0 kg in terms of Na2O, potassium salts - in amount 0.25-5.0 kg in terms of K2O, and their mixture - in amount 0.25-5.0 kg in terms of Na2O and K2O per 1 kg of REM in terms of REM oxides in composition of phosphate raw material. |
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Invention refers to liquid extraction processes, in particular to obtainment of rear-earth metals concentrates, in non-ferrous and ferrous metallurgy, during utilisation of chemical and metallurgical production waste and for purification of shaft, mine and industrial waste water. The method of rear-earth metals removal from diluted water acid solutions involves consecutive steps of liquid-phase extraction of rear-earth metals to organic phase and re-extraction of rear-earth metals from organic phase by settlement of rear-earth metals to solid phase in the form of slightly soluble salt of strong acid. |
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Method of extracting rare earth and noble metals from ash and slag 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%. |
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Method of producing scandium-bearing concentrate from red mud Invention relates to extraction of scandium oxide from red mud wastes of alumina production. This process comprises leaching said red mud by carbonate solutions at gassing of slime pump by gas-air mix containing CO2. Pulp is filtered out to produce scandium-bearing solution to separate scandium, from impurities. Scandium compounds are deposited from purified solution. Scandium concentrate is filtered out, flushed dried. Red mud leaching is performed, first, by initial vibration cavitation of pulp. Scandium is separated from impurities by sorption with phosphate ionites. Scandium is desorbed from ionite organic phase by mixed carbonate-chloride solutions in pulse mode to get scandium-bearing eluate. The latter is subjected to stepwise deposition of scandium marginally soluble compounds. Note here that, first, impurities, are deposited to separate the precipitate that represents a titanium-zirconium concentrate. Now, scandium concentrate is deposited. |
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Method of processing rare-earth phosphate concentrate Method of processing a rare-earth phosphate concentrate separated when neutralising a nitric-phosphoric acid solution obtained after breaking down apatite with nitric acid, includes treating rare-earth phosphate concentrate with nitric acid and separating the undissolved residue from the obtained rare-earth element nitrate-phosphate solution. After treatment, the undissolved residue is washed and rare-earth elements are extracted from the rare-earth element solution. The undissolved residue is washed with ammonium nitrate solution with concentration of 40-70 wt % in amount of 25 pts.wt per 1 pts.wt of the undissolved residue. The wash solution is combined with the rare-earth element solution fed for extraction, and the undissolved residue is taken for production of compound fertilisers. |
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Invention relates to methods of extracting cerium (IV) from sulphate solutions by extraction and can be used for concentration of cerium (IV) from ore, processing solutions with a complex salt composition and for analytical purposes. Extraction is carried out from 0.5-2.0 M sulphate solution with 0.32% 2-methyl-8,9-dihydro[1,2,4]triazolo[1,5-α]quinazolin-6(7H)-one solution, dissolved in methylene chloride. The phase contact time is 15 min. After demixing, the organic phase is separated and re-extraction is performed. |
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Invention relates to a method of extracting rare-earth elements from phosphoric acid when processing Khibiny apatite concentrates into fertiliser. The method includes sorption using strongly acidic macroporous cationite Purolite C-150, carried out in the temperature range of 40-80°C, washing the rare-earth element-saturated sorbent with water, desorption with ammonium nitrate solution to obtain a commercial-grade strippant and further solvent refinement of the obtained strippant with 100% tributyl phosphate. |
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Method of extracting rare-earth metals and producing gypsum plaster from phosphogypsum hemihydrate Method includes leaching rare-earth metals into a solution with recrystallisation of phosphogypsum from a calcium sulphate hemihydrate or anhydrite into a dihydrate. Leaching is carried out in a calcium salt solution in concentration of 0.075-3.75 M with respect to Ca2+ and a strong acid with pKa<0 in concentration of 0.2-8 M with respect to H+. The degree of extraction of rare-earth metals into the solution is less than 98% and the residual content of phosphorus, fluorine and alkali metal impurities in the calcium sulphate dihydrate is not more than 0.3 wt %, 0.1 wt % and 0.05 wt %, respectively. |
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Method of extracting rare-earth metals and producing gypsum plaster from phosphogypsum hemihydrate Method includes consecutive steps of recrystallising phosphogypsum and dissolving rare-earth metals. Recrystallisation of calcium sulphate hemihydrate or anhydrite into a dihydrate is carried out in the presence of a soluble calcium salt in concentration of 0.075-3.75 M with respect to Ca2+ in a weakly acidic medium at pH>1. Dissolution is carried out with a strong acid with pKa<0 in concentration of 0.2-8 M with respect to H+. The degree of extraction of rare-earth metals into the solution is less than 95% and the residual content of phosphorus, fluorine and alkali metal impurities in the calcium sulphate dihydrate is not more than 0.3 wt %, 0.1 wt % and 0.05 wt %, respectively. |
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Method of extracting rare-earth metals (rem) from phosphogypsum Proposed method comprises REM sulphuric acid leaching from gypsum pulp with application of ultrasound oscillations, separation of said pulp to REM productive solution and cake, precipitation of REM collective concentrate from productive solution with production of water phase. Pulp is prepared on the basis of sulphuric acid solutions processed by electrochemical activation. Note here REM leaching is conducted under conditions of pulp circulation at combined effects of ultrasound oscillations at cavitation and magnetisation. Leaching pulp is divided into REM productive solution and first cake. REM are precipitated from productive solution as REM oxalates with production of REM collective concentrate. Water phase after precipitation of oxalates is divided into to parts. One part is re-restored by sulphuric acid and subjected to electrochemical activation for use in circulation while another part is neutralised to get the second cake to be flushed combined with first cake and directed for gypsum production. |
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Method of loparite concentrate processing Proposed method comprises grinding of concentrate and pyrometallurgical break-down of concentrate in two steps. At first step, sodium is subjected to carbothermic reduction from concentrate by sodium evaporation at the pressure p=10-50 Pa, temperature T=1000 K and carbon content with respect to concentrate mC=2.9 wt %. Sodium vapours are withdrawn from reaction volume and condensed at T=300 K. At second step, further carbothermic reduction of produced enriched concentrate is performed at p=10-50 Pa, temperature T=2000 K and carbon content relative to enriched concentrate mC=28 wt % with reduction of refractory metal oxides to carbides in condensed phase and transition of rare earth element oxides to gas phase. Said phase is withdrawn from reaction volume and condensed at T=300 K. |
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Method of extracting rare earth elements from extraction phosphoric acid Invention relates to a method of extracting a concentrate of rare earth elements (REE) from extraction phosphoric acid. Extraction phosphoric acid with the concentration of 27-45 wt %, which contains REE and thorium, is passed through sulphoxy cationite with formation of a REE-depleted thorium-containing phosphate solution and cationite, saturated with REE. In the process of passing phosphoric acid through sulphixy cationite thorium concentration in the REE-depleted phosphate solution, which twice becomes equal to its concentration in initial phosphoric acid, is fixed. When the concentration of thorium in the REE-depleted solution for the second time becomes equal to its concentration in initial phosphoric acid, cationite is considered to be REE-saturated and passing of phosphoric acid through it is stopped. Saturated cationite is washed with water. Then desorption of REE by a solution of ammonium sulphate or nitrate with the concentration of 275-300 g/l is carried out and from the obtained desorbate a non-radioactive REE concentrate is performed. |
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Method of processing phosphogypsum Invention relates to the technology of processing phosphogypsum - wastes of enterprises, producing phosphoric fertilisers. The method includes opening phosphogypsum with sulphuric acid, further extraction of rare-earth elements (REE) and processing purified phosphogypsum with calcium oxide. In the course of opening with one solution of sulphuric acid successively processed are 1-3 lots of phosphogypsum with heating, the water phase is separated by filtration, the sediment is washed with water, apatite is added to the filtrate in a ratio of S:L=1:10-20, with the second heating at a temperature of 50-70°C and mixing for 1-2 hours with neutralisation with sulphuric acid to a concentration not lower than 0.1 mol/l. After that the sediment of the secondary phosphogypsum is separated by filtration and supplied to the beginning of the process. Calcium oxide or hydroxide and then ammonium hydroxide or carbonate are successively introduced into the filtrate until pH=2-3.5, the REE sediment is separated by filtration, and calcium hydroxide or oxide is introduced into the filtrate until pH=7-8, the sediment of feed tricalcium phosphate is separated by filtration, washed with water and discharged from the process. |
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Method of opening perovskite concentrates Method includes preliminary mechanical treatment of perovskite concentrates and subsequent treatment of activated concentrates with nitric acid solution HNO3. HNO3 treatment is carried out on activated perovskite concentrates with stored overall energy which corresponds to change in the surface of coherent scattering regions and microdeformations of not less than 16 kJ/mol perovskite. The activated concentrates are treated with 30% HNO3 solution at temperature of 90-99°C. |
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Method of extracting rare-earth elements from hydrate-phosphate residues from apatite processing Invention relates to a method of extracting rare-earth elements from nitrate-phosphate solutions from apatite processing. The method comprises dissolving apatite in nitric acid, freezing out calcium (strontium) nitrate, precipitating hydrate-phosphates of rare-earth elements and calcium (strontium), dissolving the precipitate in nitric acid, adding calcium (strontium) nitrate obtained from the freezing out step with concentration of 800-1000 g/l and heated to 40-50°C to the solution, wherein content of rare-earth elements (in terms of oxides) is kept at 40-60 g/l, and excess nitric acid 1-2 mol/l, followed by extraction of rare-earth elements with tributyl phosphate in the presence of calcium nitrate, washing and re-extraction, wherein the extract is washed with evaporated re-extraction product to rare-earth element concentration of 250-300 g/l. 70-90% of the obtained solution is removed in form of a finished product and the remaining solution is taken for washing, wherein the raffinate, which contains calcium nitrates and iron and aluminium impurities, is taken for recovering calcium (strontium) nitrate by freezing out or precipitating impurities with calcium oxide. |
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Method of purifying phosphate-fluoride concentrate of ree Invention relates to purification of a phosphate-fluoride concentrate of rare earth elements (REE), obtained in the complex apatite processing. A method of purification of the phosphate-fluoride concentrate of REE, which contains admixtures of calcium and thorium, includes processing of the concentrate with a solution of sulphuric acid with a concentration of 4-6 wt % in the presence of sulphoxide cationite. REE, admixtures of thorium and calcium are absorbed by sulphoxide cationite, transfer of fluorine together with phosphorus into the sulphuric acid solution, separation of the sulphuric acid solution from sulphoxide cationite, desorption from cationite of REE and admixtures of thorium and calcium with an ammonium salt solution with obtaining desorbate and its neutralisation with an ammonium compound in three stages. At the first stage neutralisation is carried out until pH 4.2-5.0 is achieved with formation and separation of a thorium-containing residue, at the second stage - until pH 7.0-7.5 is achieved with formation and separation of a concentrate of REE, and at the third stage - until pH not less than 8.5 is achieved with formation and separation of a calcium-containing residue. |
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Method of processing eudialyte concentrate Method involves decomposing the concentrate with inorganic acid to obtain a gel, heat treatment of the gel, regenerating the acid, water leaching the gel with transfer of rare-earth elements into the solution and a zirconium compound into an insoluble residue. The solution is then separated from the residue and the zirconium compound is separated from the residue. The concentrate is decomposed with acid consumption of 90-110% stoichiometric amount, and heat treatment of the gel, water leaching of the gel and acid regeneration are carried out simultaneously in autoclave conditions at temperature of 175-250°C for 1-4 hours to obtain a solution of rare-earth elements containing a free acid. The zirconium compound is separated from the insoluble residue by wet gravity separation. The inorganic acid used is hydrochloric acid or nitric acid. |
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Method of processing phosphogypsum for production of concentrate of rare earth metals and gypsum Method includes preparation of phosphogypsum pulp, leaching rare earth metals (REM) and phosphorus with sulphuric acid. After that, pulp is separated into REM and a phosphorus-containing solution and gypsum in the form of insoluble sediment, its neutralisation and REM sorption with cationite from the solution with obtaining mother liquor. After that, REM desorption is performed with obtaining a strippant and separation of REM concentrate from the strippant. Stage leaching is performed in the method, with supply of phosphogypsum to each stage and sulphuric acid to the first stage. Before neutralisation gypsum is subjected to water washing with obtaining a washing solution, supplied to REM sorption with cationite. Sorption mother liquor is divided into two parts, one of which is used to prepare phosphogypsum pulp, with precipitation of phosphorus and fluorine with basic calcium compound from the second one. The obtained sediment is separated from water phase and supplied to utilisation, and water phase is used in circulation. |
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Extraction of rare-earth elements from hard materials containing rare-earth metals Proposed method comprises acid leaching of solid materials ground to at least 100 mcm by the mix of sulphuric and nitric acids at their ratio of 6:1 to 1:1 parts by weight and concentration of the mix of acids lower than 15 wt % and F:S ratio varying from 2:1 to 6:1 parts by weight. At acid leaching vacuum-pulse effects are applied during the entire process of rare-earth elements conversion into solution and precipitation of remained solid material. Obtained precipitate of solid fossil and man-made materials is separated from leaching solution. Separation of rare-earth elements from leaching solution is performed with the help of ion-exchange or membrane filter. |
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Method of separating gadolinium by extraction with phosphoroorganic compounds Invention can be used in chemical industry. At the first stage of gadolinium extraction terbium, dysprosium and heavier REM are extracted from mixture of rare earth metals in organic phase. At the second stage gadolinium is extracted from obtained raffinate solution in organic phase, with main mass if europium, samarium, neodymium and other lighter REM left in water phase. gadolinium is extracted into re-extract from obtained organic phase, with all gadolinium-containing re-extract being returned to stage of washing, and the process is carried out until required content of samarium and europium in gadolinium is achieved, obtained gadolinium solution is output and the process is repeated. As extractant used are 30-40% solutions of di-2-ethylhexylphosphoric acid or bis((2,4,4)trimethylpentylphosphinic acid (Cyanex-272), or isododecylphosphetanic acid. |
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Method for solvent refining of nitrate solutions containing rare-earth metals Method involves multi-step counter-current extraction of impurities from an aqueous nitrate solution with tributyl phosphate. Purification is carried out using a solution with rare-earth metal concentration of 100-150 g/l, while using 5 extraction steps with the ratio organic phase: aqueous phase=1:1.1, 3-5 washing steps with the ratio organic phase: aqueous phase=10:1 and 5 re-extraction steps in a system of 100% tributyl phosphate and aqueous nitrate solution. A solution with content of ballast impurities of less than 4% of the sum of rare-earth metals and total specific alpha activity of less than 1·10-8 Ku/(kg rare-earth metals) is obtained. |
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Method to extract metals from silicate slags Method includes grinding of slag and leaching. To prevent formation of non-filtered pulps, specified for gel formation of silicic acid, slag is previously mixed with concentrated acid (nitric or hydrochloric), taken in quantities necessary to neutralise slag, pulp is maintained for 1-2 hours. At the same time precious components are leached, and the produced silicic acid coagulates, forming large agglomerates. After this the mass is additionally ground and leached with water. At the stage all salts are washed into the solution, and gels are not produced. Further the solution is separated by filtration or whirling and processed by available hydrometallurgical methods, and the hard silicate product is sent to a dump. |
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Method of loparite concentrate processing Pyrometallurgical processing comprises three steps: reduction, smelting and oxidation. Reduction step comprises carbothermic reduction of concentrate at limited amount of carbon in the system to reduce solely refractory metals (RM) to their carbides to get the process mix of oxides of rare-earth elements (RE) and RM carbides. Smelting step separates RE from TM carbides. Said separation consists in dissolution of RM in liquid iron. This brings about iron containing RM and slag composed by target product, i.e. RE oxides. Third oxidation step consists in processing RM-bearing iron with oxygen to produce steel and iron on the base of RM oxides. |
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Method of extracting rare-earth elements from phosphogypsum Invention can be used in chemical industry to extract rare-earth elements from phosphogypsum. The method involves carbonising phosphogypsum to obtain phosphochalk, dissolving said phosphochalk in nitric acid to obtain a product suspension and then separating the insoluble residue - a black concentrate of rare-earth elements - by filtering. The product suspension is divided into two parts, one of which is fed for filtration to separate the insoluble residue - black concentrate, and the second is fed for premixing with nitric acid. The mixing process is carried out for 3-5 minutes with the ratio CaO/HNO3 equal to 0.75-2.25. When dissolving, pH is kept at 2.2-4. |
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Method of extracting rare-earth elements from wet-process phosphoric acid Invention relates to methods of extracting a concentrate of rare-earth elements from wet-process phosphoric acid, which is obtained in a dihydrate process of treating an apatite concentrate, and can be used in industry. Wet-process phosphoric acid heated to 65-80°C, which contains rare-earth elements and fluorine, aluminium, titanium and iron impurities, is mixed with ammonia in an amount which ensures the molar ratio NH3:P2O5=(0.2-1.0):1. Ammonium fluoride is then added to the acid in amount of 20-30 g/l to obtain a suspension and transfer the main part of rare-earth elements and part of the impurity components into the precipitate. The precipitate of the rare-earth element concentrate is separated from the phosphoric acid solution. |
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Method for opening perovskite concentrate Method involves carbothermal vacuum treatment. Prior to carbothermal treatment, a charge is prepared, which consists of perovskite concentrate and carbon-containing material in the ratio suitable for formation of calcium carbide, and titanium carbides and oxycarbides. Opening is performed in one unit in two stages. At the first stage, carbothermal treatment is performed at the temperature of 1100-1300°C and residual pressure of 10-100 Pa so that solid mixture of calcium carbides and titanium carbides and oxycarbides is obtained. The second stage is performed at the temperature of 1400-1500°C and pressure of 5-10 Pa for dissociation of calcium carbide and its stripping so that elementary calcium and carbon is obtained and with concentration in the residue of precious components of titanium, tantalum, niobium and rare-earth metals, which are contained in perovskite concentrate and are subject to chlorination. |
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Phosphosemihydrate processing method Invention refers to processing of freshly obtained phosphosemihydrate and can be used to obtain concentrate of rare-earth elements (REE) and gypsum product for construction materials. Phosphosemihydrate is processed with water solution containing fluorine-ion. Sulphuric acid leaching is performed with displacement and separation of the water solution containing fluorine-ion, as well as with conversion of REE and impurity components to a leaching solution and production of a phosphosemihydrate layer saturated with a sulphuric-acid solution. Then, water displacement of the remaining amount of sulphuric acid solution is performed so that washed phosphosemihydrate and a leaching solution is obtained Phosphosemihydrate is neutralised with a calcium-containing reagent so that a gypsum product is obtained. Rare-earth elements and impurity components are extracted from the leaching solution by sorption using sulphoxy cationite so that a lean sulphuric-acid solution is formed; REE and impurity components are desorbed from saturated cationite by its processing with an ammonium sulphate solution so that a strippant is obtained; REE and impurity components are deposited from the strippant with an ammonium-containing precipitator in two stages and REE deposit is separated. |
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Method for opening loparite concentrates Invention refers to metallurgy of rare metals. A method for opening loparite concentrates involves preliminary machining of loparite concentrates and further treatment of activated loparite concentrates with 30% of HNO3 solution at the temperature of 99 °C. To further treatment there subject are activated loparite concentrates with double amount of energy of variation of loparite crystal lattice parameters of at least 73 kJ/mole and with stored total amount of energy, which corresponds to surface of areas of coherent dissipation and microdeformations with at least 9.5 kJ/mole of loparite. |
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Method of processing phosphogypsum Method of processing phosphogypsum involves step-by-step agitation sulphuric-acid leaching of rare-earth metals and phosphorus while feeding sulphuric acid to the head step, using the obtained leaching solution of the head step at subsequent leaching steps, separating the undissolved residue from pulp of a tail step and washing with water, treating the leaching solution of the tail step to obtain a mother solution, using the mother solution and the washing solution for leaching. Leaching of the rare-earth metals and phosphorus at the second and subsequent steps is carried out from a mixture of phosphogypsum and the leached pulp from the previous step. Sulphuric acid is fed to the head leaching step in an amount which enables to extract rare-earth metals and phosphorus into the solution at the head step and subsequent steps at pH values at the tail leaching step not higher than pH at the onset of precipitation of rare-earth metal phosphates. The tail step for leaching rare-earth metals and phosphorus is carried out while simultaneously treating the leaching solution by extracting rare-earth metals by sorption with a cationite. The rare-earth metal-saturated cationite is separated from the mother pulp and taken for producing a rare-earth metal concentrate. A portion of the mother solution is pre-purified from phosphorus by precipitation thereof with a basic calcium compound. The obtained phosphorus-containing precipitate is fed for recycling. |
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Plasma-carbon production method of rare-earth metals, and device for its implementation Method involves carbon thermal reduction of oxide compound of rare-earth metal in vacuum so that powder of rare-earth metal carbide, which is free from residues of oxygen impurity, is obtained. Then, it is cooled down and mixed with high-melting metal powder in the ratio that is sufficient for performance of exchange reactions between rare-earth metal carbide and high-melting metal, and mixture is heated with hot volumetric plasma discharge to the temperature of ≥1800°C. With that, evaporating rare-earth metal is collected on condensers and hard-alloy carbide of high-melting metal is obtained. The device includes a vacuum system, cathode and anode assemblies arranged concentrically in the chamber, and a steam line and a condenser-cooler, which are coaxial to them. With that, an internal electrode represents an anode of high-current vacuum plasma discharge burning in an annular discharge cavity formed with coaxial cylindrical electrodes. The anode is made from high-melting electrically conducting material in the form of a crucible having a capacity, and a thin-wall cathode enveloping it, outside which there located is a starting resistance heater, is also made from high-melting electrically conducting material, for example tungsten, tantalum or graphite. |
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Cerium extraction is performed after preliminary preparation of a catalyser. Crushing of the used catalyser is performed. Crushed catalyser is subject to annealing at the temperature of 650-800°C during 3-6 hours. After annealing the catalyser is cooled down to room temperature and cerium compound is extracted by dilution of ignited catalyser in concentrated hydrochloric acid. Obtained solution with suspended particles of cerium dioxide is heated to boiling, exposed at boiling temperature of 100-110°C during 30-120 minutes and during 3-12 hours at temperature of 0-20°C so that a deposition is obtained. The obtained deposition is separated from mother solution by means of filtration by draining the solution from the deposition surface to a filter with the size of filtering material pores of not more than 2 mcm. Deposition on the filter is washed from iron compound and dried till constant weight of cerium dioxide. |
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Method of extraction of rich components from production solutions for processing of black-shale ores Method includes sorption of rich components from production solutions by ion-exchange material counterflow under controlled pH of environment and oxidation-reduction potential Eh. Sorption is performed by ion-exchange materials in stages from production solutions containing uranium, molybdenum, vanadium and rare earth elements. At the first stage uranium and molybdenum are extracted by anion-exchange material sorption. At the second stage vanadium is extracted by anion-exchange material sorption with hydrogen dioxide available at Eh of 750-800 mV, pH of 1.8-2.0 and temperature of 60°C, at that vanadium sorption is performed till complete destruction of hydrogen dioxide and till Eh is below 400 mV. Then barren solutions are transferred to cationite at pH of 2.0-2.5 and Eh of 300-350 mV for extraction of rare earth elements. |
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Processing method of black-shale ores Processing method of black-shale ores includes crushing, counterflow two-stage leaching by sulfuric acid solution upon heating, separation of pulps formed after leaching at both stages by filtration. Then valuable soluble materials are washed from deposit at the second stage with strengthened and washing solutions being produced, marketable filtrate is clarified at the first stage for its further processing. Ore is crushed till the size of 0.2 mm, leaching at the first stage is performed by cycling acid solution with vanadium under atmospheric pressure, temperature of 65-95°C during 2-3 hours, till residual content of free sulphuric acid is equal to 5-15 g/l. Leaching at the second stage is performed at sulphuric acid rate of 9-12% from the quantity of initial hard material under pressure of 10-15 atm and temperature of 140-160°C during 2-3 hours. Cake filtered after the first stage is unpulped by part of strengthened solution which content is specified within 35-45% of total quantity. |
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Processing method of black-shale ores with rare metals extracting Processing method of black-shale ores with rare metals extracting includes leaching of ore by sulphuric acid solution with dilution of rare metals. Leaching is performed in autoclave by sulphuric acid solution consisting of free and combined sulphuric acid with ratio of H2SO4(free):H2SO4(comb)=2:1, and containing 25-45 g/l of iron sulphate, 70-90 g/l of aluminium sulphate and 0.5 g/l of nitric acid. At that the process is performed under pressure in autoclave equal to 10-15 atm with mixing at temperature of 140-160°C in concentration range of general H2SO4(gen) equal to 350-450 g/l under pulp density S: L=1:0.7-0.9, preferably 1:0.8, under constant oxidation-reduction potential Eh in the system equal to 350-450 mV during 2-3 hours till residual concentration of free H2SO4(free) is within 45-75 g/l. |
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Method of extracting rare-earth metals (rem) from phosphogypsum Proposed method comprises REM and phosphorus leeching by sulfuric acid solution to obtain leaching solution and insoluble residue. Said insoluble solution is processed by calcium compound to pH over 5. PEM concentrate is extracted from said solution by crystallisation and fed to REM and phosphorus leaching stage. Prior to leaching phosphogypsum is subjected to flushing with water to obtain flushing solution containing REM and phosphorus. Said insoluble residue is flushed before processing by calcium compound. Obtained flushing solution is processed by calcium compound to produce pulp with pH not over that of REM phosphate precipitation beginning and combied with said flushing solution. REM is sorbed by cation exchangers and separated to desorb REM therefrom to produce desorbent and recovered cation exchanger. Said recovered cation exchanger is sent to REM sorption while desorbent is sent to REM concentrate production stage. Phosphorus and associated impurities are deposited from sorption mother pulp. Obtained pulp is separated in residue to be recovered and water phase to be used as circulating water. |
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Method of extracting rare-earth metals from phosphogypsum Method includes leaching of rare-earth metals (REM) from phosphogypsum with 1-5% solution of sulphuric acid, REM sorption from leaching solution with cationite, REM desorption, precipitation of REM concentrate from desorbate, obtaining REM concentrate and mother liquor, which is used for REM desorption. Cationite after desorption is returned at sorption stage. Phosphor and fluorine are precipitated from mother liquor, phosphor -and fluorine-containing sediment are filtered and filtrate is used as return water in leaching. REM leaching and sorption are carried out simultaneously. Obtained pulp is filtered through mesh filter with separation of saturated REM cationite. After that, pulp is filtered with obtaining non-dissoluble residue and mother liquor of sorption. Before desorption cationite is treated with part of desorbate. |
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Method for quantitative determination of cerium in steels and alloys Method includes dissolution of a sample of analysed alloy and separation of cerium from the base of the alloy and macrocomponents. At the same time the base and macrocomponents are separated from cerium by serial deposition and extraction of the alloy base and macrocomponents of the alloy from the solution. Deposition is carried out with sodium diethyldithiocarbamate, extraction - with dithizone in chloroform. After separation of the organic phase, the cerium content is detected in water phase with the spectrometric method. |
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Method of extracting rare-earth metals from phosphogypsum Invention is meant for extracting rare-earth metals from phosphogypsum obtained in production of phosphorus fertiliser during sulphuric acid treatment of apatite. The method of extracting rare-earth metals from phosphogypsum involves converting phosphogypsum, dissolving the converted chalk to obtain an insoluble residue containing rare-earth metals. The obtained insoluble residue containing rare-earth metals is dissolved in nitric acid solution at solid-to-liquid ratio of 1:1.5 to obtain a solution and an insoluble residue. The insoluble residue is then washed with water; the obtained solution is mixed with the washing solution; the mixed solution is neutralised to acidity of 0.5-0.25 N with concentrated aqueous ammonia solution and taken for precipitation of rare-earth metal oxalates. The oxalates are precipitated with saturated oxalic acid solution; the residue is washed with 1.5-2.5% oxalic acid solution at solid-to-liquid ratio of 1:2-3. The oxalates are then dried and calcined until rare-earth metal oxides are obtained. |
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Solid extractant for extraction of scandium and method of its production Solid extractant is proposed (SEX) for extraction of scandium from scandium-containing solutions, containing a styrene divinyl benzene matrix with di-(2-ethyl hexyl)phosphoric acid. At the same time it additionally contains dibenzo-18-crown-6 at the following ratio of components, wt %: di-(2-ethyl hexyl)phosphoric acid 28-30, dibenzo-18-crown-6 28-30, styrene divinyl benzene - balance, besides, the ratio of styrene and divinyl benzene in the matrix is equal to 65÷70:30÷35. There is a method also suggested for production of the above extractant. |
Another patent 2551095.