Method of treating rare-earth phosphate concentrate separated from apatite

IPC classes for russian patent Method of treating rare-earth phosphate concentrate separated from apatite (RU 2484018):

C22B59 - Obtaining rare earth metals

C22B3/06 - in inorganic acid solutions

C01F17 - Compounds of the rare-earth metals, i.e. scandium, yttrium, lanthanum, or the group of the lanthanides

Another patents in same IPC classes:

Method of making scandium oxide from red slag / 2483131

Proposed method comprises multistep leaching of red slag by the mix of sodium carbonate and bicarbonate on forcing annealing furnace flue gases containing carbon dioxide there through to obtained solution. Then, three-step holding of said solution at increased temperatures is performed along with selective separation of precipitates after every said step. At first step, said solution is heated to temperature not exceeding 80°C for, at least, 1 hour. Thereafter, it is settled for, at least, two hours at natural cooling. At second step, said solution is boiled and mixed for, at least, two hours. At third step, said solution is evaporated to 50% of initial volume to add 46%-solution of sodium hydroxide to concentration of Na₂O_caustic of 1.5-2.0 kg/m³. Now, it is boiled for, at least, 2 hours and precipitate containing scandium oxide is settled for 10-16 hours at natural cooling.

Method for europium (iii) from salt solutions / 2482201

Invention relates to hydrometallurgy, in particular, to the method for extraction of europium (III) from salt solutions by floating extraction. In process of floating extraction of europium (III) cations the organic phase is represented by isooctyl alcohol, and the collector of surfactants of anion type is sodium sodium dodecyl sulfate in the concentration corresponding reaction stoichiometry: Eu⁺³+3NaDS=Eu(DS)3+Na⁺, where Eu⁺³ - cation of europium (III), DS^- - dodecyl sulfate-ion. At the same time the floating extraction is carried out at pH=7.5-8.5, and at the ratio of organic and water phases 1/20-1/40.

Processing method of red muds of alumina industry / 2480412

Invention refers to non-ferrous metallurgy, and namely to complex processing of red muds of alumina industry. Processing method of red muds of alumina industry involves obtaining of red mud pulp, extraction and concentration of rich components by combination of classification and magnetic separation methods. After the pulp classification, fine-grain fraction pulp is extracted and subject to vibrocavitation treatment and further magnetic separation with extraction of magnetic and non-magnetic products. At that, magnetic product is subject to additional classification so that iron-bearing and scandium-bearing concentrates are obtained.

Method of producing scandium oxide / 2478725

Proposed method comprises dissolving scandium-bearing concentrate in sulfuric acid, removing acid-insoluble residue, and precipitating scandium in the presence of ammonium compounds. Then, precipitate is filtered, flushed, dried and calcined to obtain scandium oxide precipitate. With acid-insoluble residue removed, sulfuric acid concentration in filtrate is increased to 540-600 g/dm³, ammonium chloride is added to solution in amount of 26.7-53.5 g/dm³ at 50-70°C and held for one hour at mixing. Produced precipitate is flushed by ethanol at volume ratio of 1-10-11.

Method of extracting yttrium (iii) from salt solutions / 2478724

Method of extracting yttrium (III) from salt solutions involves floatation extraction using an organic phase and a collector. The organic phase used is isooctyl alcohol. The collector used is an anionic surfactant - sodiium dodecyl suphate in a concentration which corresponds to the stoichiometry: Y⁺³+SDS^-=Y[DS]₃, where Y⁺³ is a yttrium cation, DS^- is a dodecyl sulphate ion. Floatation extraction is carried out at pH=7.0-7.8 and ratio of the organic phase to the aqueous phase of 1/20-1/40.

Complex processing method of carbon-silicic black-shale ores / 2477327

Invention refers to complex processing method of carbon-silicic black-shale ores, which contain vanadium, uranium, molybdenum and rare-earth elements. The above method involves ore crushing to the particle size of not more than 0.2 mm and two leaching stages. Oxidation sulphuric-acid leaching is performed at atmospheric pressure. Autoclave oxidation sulphuric-acid leaching is performed at the temperature of 130-150°C in presence of oxygen-containing gas and addition of a substance forming nitrogen oxide, as a catalyst of oxygen oxidation. Ion-exchange sorption of uranium, molybdenum, vanadium and rare-earth elements is performed from the obtained product solution.

Method of extracting rare-earth elements from phosphogypsum / 2473708

Invention relates to the technology of producing compounds of rare-earth elements during complex processing of apatites, particularly extraction of rare-earth elements from phosphogypsum. The method involves preparation of pulp from phosphogypsum and sorption of rare-earth elements on a sorbent. The pulp is prepared from ground phosphogypsum and sulphuric acid solution with pH=0.5-2.5 until achieving liquid:solid ratio of 4-7. Sorption is carried out directly from the phosphogypsum pulp on a sorbent with sulphuric acid functional groups for 5-7 hours with solid:sorbent ratio of 4-7.

Universal method of selective extraction of salts of transition, rare-earth and actinoid elements from combination solutions by means of nanoporous materials / 2472863

Method involves selective extraction of salts in volumes of nanopores of nanoporous conducting materials due to effect of electrostatic interaction of dipole moments of solvated ionic complexes of transition, rare-earth and actinoid elements with electric field of double electric layer of "nanopore wall - solution" boundary line. The method is implemented by subsequent filling of nanopore of nanoporous conducting material with the solution containing ionic complexes of transition, and/or rare-earth and/or actinoid elements, displacement from nanopore of ionic complexes of transition, rare-earth and actinoid elements weakly localised in nanopores by means of pressure of gases or liquids, by filling of nanopore with solution of inorganic acid of high concentration, and by extracting from nanopores of residual ionic complexes of transition, rare-earth and actinoid elements by means of pressure of gases or liquids. The above method can be implemented in an electrochemical cell.

Extraction method of rare-earth metals from phosphogypsum / 2471011

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

Processing method of micro production wastes of constant magnets / 2469116

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

Processing method of scraps of anodes of tantalum oxide-semiconductor capacitors / 2480529

Method involves cleaning of scraps by acid treatment with removal of manganese dioxide. Then, deoxidation of cleaned scraps, its hydration, grinding, dehydration at increased temperature is performed so that tantalum hydride powder is agglomerated and tantalum capacitor powder is obtained. At that, acid treatment is performed at room temperature using the solution containing 100-300 g/l of sulphuric acid and 110-300 g/l of hydrogen dioxide, or the solution containing 30-150 g/l of hydrochloric acid and 75-225 g/l of hydrogen dioxide. Scrap hydration is performed by treatment using the solution of hydrofluoric acid with concentration of 1-5%. The obtained capacitor tantalum powder provides specific charge of up to 7300 mcC/g, breakdown voltage of more than 200 V and leakage current of 0.0001-0.0003 mcA/mcC when being used in anodes of tantalum oxide-semiconductor capacitors.

Method of producing scandium oxide / 2478725

Processing method of low-grade molybdenite concentrates / 2477328

Method involves two-stage processing of concentrates with water solution of nitric acid, pulp filtration so that cake and molybdenum-containing solution is obtained. Then, calcium molybdate suitable for making of ferromolybdenum is deposited from the solution. Decomposition of concentrates is performed at addition to water solution of nitric acid, sulphuric acid in the quantity sufficient for retention of the whole molybdenum in the solution in composition of water-soluble sulphate compounds of molybdenyl, and namely with anionic complex [MoO₂(SO₄)₂]^2-.

Processing method of micro production wastes of constant magnets / 2469116

Treatment method of sulphide concentrates containing precious metals / 2457263

Method involves leaching with further separation of non-soluble residue from the solution, its drying and further melting when it is mixed with sodium carbonate, silicon-containing flux, borax so that alloy of precious metals and slag is obtained. At that, original concentrate is subject to leaching by means of nitric acid solution. Melting is performed using the addition of sodium chloride to mixture. Concentrate is leached using nitric acid solution with mass concentration of 350-550 g/l. Sodium chloride is added to mixture for melting purpose in quantity which is more by 10-20% than stoichiometric quantity as per lead chloride obtaining reaction.

Method of processing natural uranium chemical concentrate / 2451761

Invention relates to processing natural uranium chemical concentrate. Proposed method comprises concentrate leaching by nitric acid solution to obtain suspension, adding coagulant into suspension and suspension separation. Clarified solution is separated from residue and directed to extraction. Note here that polyacrylamide-based anion coagulant is used and suspension with said coagulant is subjected to permanent magnetic field effects. Coagulant concentration and duration of magnetic field effects are selected to ensure concentration of insoluble residue now exceeding 100 mg/l in clarified solution. In extraction from clarified solution, no antifloating emulsions are observed.

Method for obtaining dephosphorised concentrate of oolitic iron ores / 2449031

Invention refers to preparation of iron-ore raw material for metallurgical treatment by cleaning the latter from harmful impurities deteriorating the quality of obtained metals and alloys. Method for obtaining dephosphorised concentrate of oolitic iron ores involves high temperature treatment, cooling and leaching of concentrate with mineral acid. High temperature treatment of iron-bearing material is performed in the range of 1350-1450°C in reducing medium with participation of clinker minerals till molten metal and sinters are formed. They are cooled to magnetising roasting temperature of 750-860°C, crushed and separated with magnetic separation into clinker and concentrate. Then, concentrate is cooled to 50-90°C and supplied at that temperature for leaching with mineral acid for dilution of phosphorus.

Method of processing manganese-containing material / 2448175

Method involves transfer of manganese and accompanying impurities into a solution through two-step treatment of the starting material with hydrochloric acid and absorption of chlorine with an alkaline solution. Further, impurities are separated to obtain a manganese salt solution which is then treated. The first step uses waste hydrochloric acid with concentration 1-10% with solid to liquid ratio equal to 1:(3-5). A manganese-containing residue is separated from the obtained pulp, where said residue is then treated at the second step with waste inhibited hydrochloric acid with concentration 20-24% and content of inhibitor of not less than 5 wt %, reaction with iron of which results in insoluble complex compounds, where said inhibitor is in form of quaternary ammonium salts, with molar ratio manganese:HCl=1.0:1.1. The insoluble residue of aluminosilicates is then separated and the manganese salt solution is then processed using existing methods.

Extraction of metals from sulphide minerals / 2448171

Method has been elaborated for two-stage dilution of nickel in leaching acid. Suspension of mineral and acid is activated by oxidation. It is performed during T1 time by means of electrolysis or alternatively chemically, by adding for example of oxidating acid to mineral. After activation the suspension is exposed in oxygen-free conditions during T2 time. During T2 time much quicker dilution of sulphide begins; quick decomposition of sulphide gives the possibility to nickel to be diluted and thus leached from mineral. Diluted nickel is extracted from leaching acid for example by electrochemical extraction.

Method of processing chemical concentrate of natural uranium / 2447168

Method involves leaching the concentrate with aqueous nitric acid solution at high temperature to obtain a pulp consisting a solid and an aqueous phase. The aqueous phase is then separated by filtration from the solid phase in form of uranium nitrate solution. Uranium is then extracted from the nitrate solution using tributyl phosphate in a hydrocarbon solvent. The extract is washed and uranium is re-extracted. Leaching is carried out by adding nitric acid and water in an amount which enables to obtain a nitrate solution in the aqueous phase of the pulp, said nitrate solution containing dissolved silicon in concentration of 2.5-3.7 g/l. The solid phase, which consists of insoluble concentrate residues, is separated by filtration from the solution which contains dissolved silicon, uranium in concentration of 170-250 g/l and nitric acid in concentration of 80-120 g/l. Filtration is carried out not more than 24 hours after leaching, preferably not more than 5 hours after leaching.

Method of making scandium oxide from red slag / 2483131

FIELD: chemistry.

SUBSTANCE: invention relates to methods of separating deactivated rare-earth elements during nitric acid treatment of apatite concentrate from nitrate-phosphate solutions. The method of treating a rare-earth phosphate concentrate isolated from apatite involves decomposition of the rare-earth phosphate concentrate with nitric acid, treating the obtained solution with oxalic acid with precipitation of rare-earth oxalates in two steps, at the first step of precipitation of oxalates of thorium and rare-earth elements, 5-10% oxalic acid in stoichiometric amount is added to rare-earth elements present in the solution, and at the second step of precipitation of rare-earth oxalates, 110-115% oxalic acid in stoichiometric amount is added to rare-earth elements present in the initial solution, and the rare-earth oxalates are then calcined to rare-earth oxides.

EFFECT: invention provides high economic efficiency of the process, which is achieved by avoiding the need to process and bury the precipitate containing thorium.

3 cl, 2 ex

The invention relates to a method of allocating deactivated rare earth elements (REE) in nitric acid processing of Apatite concentrate from nitrogen and phosphate solutions obtained by dissolving the phosphate concentrate REE.

The Khibiny Apatite concentrate contains ≈1% REE oxides. The content of thorium 0,001-0,003%, which determines the specific activity of 0.004-0,12B/g, lower than the permissible limits for non-radioactive materials, in accordance with the Sanitary rules (JV 2.6.1.798-99)≤to 0.74 Bq/g due To the close chemical properties to the properties of the REE, selecting REE of Apatite concentrate thorium is concentrated in the final product - oxides REE content of 0.1-0.3%. The specific activity of rare earth product is 4.2 to 12.5 Bq/g, which, according to the Sanitary rules, it is not possible to attribute it to non-radioactive materials.

A method of refining rare earth phosphate concentrate, isolated from Apatite, including the decomposition of REE concentrate concentrated (10-12N) nitric or hydrochloric acid when heated, processing the obtained solution of oxalic acid when it is 200%excess over the stoichiometric quantity to REE with deposition of oxalates of the rare earths, Department of oxalate precipitate, washing and calcination to obtain the sum of the REE oxides containing 93-95% of the foundations of the CSOs substances, 5-7% of impurities, mainly calcium, iron, silicon, phosphorus. ("Complex of nitric acid processing of phosphate rock. Ed. Goldikova A.L. and Kopylova B.A. - L: Chemistry, 1982, s-159)

A method of refining rare earth phosphate concentrate, isolated from Apatite. /Patent RU No. 2148019, MKI CO1F 17/00, SW 3/06/. Decomposition of rare earth phosphate concentrate REE was carried out by simultaneous dissolution in nitric or hydrochloric acid in the presence of oxalic acid. The precipitate of oxalate is washed with water and made red-hot until the REE oxides. This method is adopted for the prototype.

The disadvantages of these methods is to obtain REE oxides with a thorium content of exceeding health standards (JV 2.6.1.798-99). The operation of separation of thorium these methods of processing of phosphate of rare earth concentrates to oxides of rare-earth elements is not provided.

There is also known a method of decontamination of the REE in the processing of loparite concentrate by allocations from the nitric acid solution REE relettering cake, which undergoes further processing and disposal. (Patent No. 2145980 "Method for processing of loparite concentrate", MKI SW 59/00, 34/12).

The disadvantage of this method is the need for additional processing of iron-thorium cake and organization of his burial.

Also known the way of extras is clonage separation of thorium from rare earth elements during their extraction with tributyl phosphate. (Zelikman. N.A. and other "metallurgy of rare earths, thorium and uranium". Of ferrous and nonferrous metallurgy. M, 1960).

The disadvantages of this method include its multi-stage, introduction organophosphorus compounds that fertilizer is not recommended, as the ingress of impurities organophosphorus compounds, which are prone to hydrolysis, can cause spontaneous decomposition of ammonium nitrate, which is included in the fertilizer. In addition, the allocation of concentrates of thorium from the organic solutions will require additional work on their recycling and landfill or storage of imported thorium products.

The technical result of this invention is to provide a decontaminated total rare earth concentrates in nitric-acid treatment of Apatite with the exception of discharges, increase the economic efficiency of the method due to its simplicity.

The technical result is achieved by the fact that nitrogen and phosphate solutions, obtained by the decomposition of rare earth phosphate concentrate nitric acid, is fractional (two-stage) precipitation of oxalates REE. At the first stage of deposition is introduced oxalic acid in the amount of 5-10% of stoichiometry on the REE present in the solution. Consumption of oxalic acid in the second stage of deposition of the Oxus is the ATA is 110-115% of stoichiometry on REE, contained source of nitrogen-phosphate solution. The thorium oxalate precipitates together with a part of oxalates REE. The precipitate of oxalate of thorium and REE is separated from the solution by filtration. Sediment washed from the filter with the flow of the filtrate obtained in the second stage of deposition is deactivated oxalates REE, then return in the manufacture of fertilizers.

The resulting suspension by dilution of sludge filtrate aradioactive and may be sent in the production of fertilizers. Thus, thorium, who was in Apatite concentrate and passed into the main product is fertilizer, returns again in their production.

After the second stage of deposition receive oxalates REE with specific activity of 0.13-0.2 Bq/g that satisfy the health standards JV 2.6.1.798-99. For materials which are allowed to work without restrictions specific activity must be <to 0.74 Bq/g mother liquor of the second stage of deposition of REE also aradioactive.

The advantage of the proposed method lies in the fact that after calcination of the oxalate REE obtained in the second stage of deposition, the REE oxides of aradioactive and correspond to class 1 according to sanitary rules, allowing to work with them without restrictions. In addition, recycling of sludge containing thorium does not require additional costs for processing and disposal,which makes the process of allocating REE cost-effective.

Example 1. The experiments were conducted using nitrate-phosphate solutions obtained in the production of fertilizers JSC ACRON after allocation calcium nitrate. This solution was selected crematoria sodium. Received nitrate-phosphate solution had the composition, ppm,%:

RSA - 0,47; Th - 0,00047; P₂O₅- 22,5; Sa - 3,82; F - 0,2.

This solution was precipitated with gaseous ammonia phosphate of rare earth concentrate (FRSC) at pH of 1.4. Sediment FRSC separated from solution and was dissolved in 12N nitric acid. The obtained nitrogen-phosphate solution (PRA) composition, ppm,%:

RSA - 6,67; Th - 0,0067; P₂O₅of 6.31; Ca - 1,06; HNO₃- UN; F - 0,001;

was heated to 90°C and then added to a solution of oxalic acid. Consumption of oxalic acid - 5% of the content of REE in Pras. Recovery of REE in terms of acidity 1,3N and small consumption of oxalic acid is 2% of the content in Pras. The resulting suspension was kept at 20-25°C for 20 hours. Then the precipitate was separated from the solution by filtration. Nitric-phosphoric acid solution after the precipitate was treated with oxalic acid at a temperature of 70-80°C for 1 hour. Consumption of oxalic acid - 115% from the content of REE in the original PRA. The resulting suspension was kept at 20-25°C for 2 hours. After that, the precipitate of oxalate REE were separated by filtration. The filtrate e.g. ulali flush first precipitate of oxalate of thorium and REE. The resultant slurry composition, ppm,%:

RSA - 0,1; Th - 0,004; P₂O₅and 4.4; Sa - 0,7; C₂O^-4 - 0,18; specific activity is 0.17 Bq/g; goes into the production of fertilizers on the stage of neutralization. Oxalates REE obtained in the second stage of the deposition, was dried and progulivali at 800°C for 6 hours. The composition of REE oxides, ppm,%:

RSA - 99; Th - 0,005; P₂O₅- 0,4; Sa - 0,3; specific activity of 0.2 Bq/g Extract REE 98% of the content in the original PRA.

Example 2. Experiments on the proposed method described in example 1, except that the nitrate-phosphate solution contained a greater quantity of thorium. The composition of the solution, ppm,%:

RSO to 0.5; Th Is 0.0015; P₂O₅- 23; Sa - 3,9; F - 0,18.

After deposition FRSC and dissolving it in nitric acid obtained nitrogen-phosphate solution composition, ppm,%:

RSA - 4,86; Th - 0,015; Ca - 0,73; F - 0,001; HNO₃- 1,9N.

Consumption of oxalic acid in the first stage of deposition of oxalates thorium and REE was 10% of the content of REE in Pras. Consumption of oxalic acid in the second stage of the deposition of pure oxalate REE - 110% of the contents of REE in the original PRA. Recovery of REE in the first residue 5% of the content in the original PRA. Recovery of REE in the second precipitate of oxalate - 95%. Suspension after flushing the first precipitate of oxalate of thorium and REE with filter had composition, ppm,%:

RSA - 0,24; Th - 0,012; Ca - 0,52; $C_{2} O_{4}^{-} - 0,32$ ; specific activity of 0.5 Bq/g

The composition of REE oxides obtained after calcination of the deactivated oxalates, ppm,%:

RSA - 99; Th - 0,003; P₂O₅to 0.3; Sa - 0,2; specific activity to 0.13 Bq/year

The positive effect of decontamination REE proposed method provides a two stage deposition process oxalates, where in the first stage is the separation of thorium from the base REE contained in the products of processing of Apatite with a view to their allocation. The economic efficiency of the process is achieved without the need for recycling and disposal of products containing thorium.

1. A method of processing rare earth phosphate concentrate, isolated from Apatite, including the decomposition of rare earth phosphate concentrate nitric acid, processing the obtained solution of oxalic acid precipitation of oxalates REE and their annealing to REE oxides, characterized in that the treatment with oxalic acid lead in two stages, with the first stage of deposition of oxalates thorium and REE serves 5-10% of oxalic acid from stoichiometry on the REE present in the solution, the second stage precipitation of oxalates REE - 110-115% of oxalic acid from stagione the AI on REE, present in the initial solution.

2. The method according to claim 1, characterized in that the precipitate of oxalate of thorium and REE, resulting in the first stage of deposition, wash off with the filter, the filtrate separated from the precipitate of oxalate of REE in the second stage of deposition, washout from the filter with a specific activity of 0.17 to 0.5 Bq/g return in the manufacture of fertilizers.

3. The method according to claim 1, characterized in that in the second stage sedimentation get oxalates REE, not containing thorium, after annealing gives the REE oxides with specific activity of 0.13-0.2 Bq/year