Method of extracting rare-earth metals from phosphogypsum

FIELD: chemistry.

SUBSTANCE: 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.

EFFECT: simplification of technology, reduction of duration of REM leaching and sorption, increased efficiency of sorption and desorption and concentrate quality.

12 cl, 1 dwg, 3 ex

 

The invention relates to the chemical industry, in particular to the processing of phosphogypsum.

Important future raw material source of rare earth metals lanthanides and yttrium (hereinafter REM) is the phosphogypsum waste sulfuric acid refining of mineral fertilizers Khibiny Apatite concentrate. As we know from the sources listed below, phosphogypsum is presented in the form of postopera (FPG) and positiverate (FDG). REM figs are mainly in the form of micro-crystals of hydrated phosphates (REM)RHO4·mo2About associated with SrSO4(Celestine), i.e. not decrystallizing isomorphic with bassanio 2CaSO4·H2O. Relatively effective sulfuric acid leaching of REE from figs possible only after at least 1 to 2 months of storage (aging). This is due to the transition of a significant part of miscegination REE phosphates in fluoride, which is characterized by a higher solubility in sulfuric acid solutions with the formation of complexes (REM)SO4F, as a result of hydrolysis reactions contained in phosphogypsum of cremetorium, in particular crematoria sodium:

Na2SiF6+2H2O→SiO2+2NaF+4HF

and interaction of the obtained hydrofluoric acid with phosphate REM

(REM)RHO4·nH2O+3HF=(REM)F3+H3RHO4+mo 2O.

In contrast to figs main part of REM (≥70%) in FDG isomorphic cocrystallization with plaster SO4·2H2O, replacing it together with ions of Na+(K+) ions of CA2+in particular:

2CaSO4+(REM)3++Na+→(REM)Na(SO4)2+2Ca2+.

Some of the rare, especially in FDG, is apparently in the form of hydrated double sulfates of Na(REM)(SO4)2·H2O. In phosphogypsum contains both water-soluble phosphorus in the deposited moisture phosphoric acid and water-insoluble phosphorus in the form of unreacted sulfuric acid Apatite and phosphate, as well as anions NRA42-isomorphically alternates in CaSO4sulfate anions.

There is a method of extraction of lanthanides from phosphogypsum by leaching dilute 0.5 to 1.0%-governmental solutions of sulfuric acid (see, Lebedev V.N., and others, Extracting rare earth elements from phosphogypsum leaching methods. // Physical-chemical and technological problems of processing of raw materials of the Kola Peninsula. - St. Petersburg: Nauka, 1993. - P.56-60).

Significant disadvantages of this method are the high W:T=(5-10):1 (ratio of liquid and solid phases during leaching) and correspondingly low (from 0.25 to 0.37 g/l) content of lanthanides in productive solution at relatively low ~32-43%removing them from phosphogypsum. This technology is practical indicators determine the technical and economic inefficiency of the method for practical use.

The method for extracting rare-earth metals from phosphogypsum (EN 2225892 C1, Lokshin AP and others, 20.03.2004), including sequential leaching of REE from some portions of phosphogypsum working solution 20-25%sulfuric acid at W:T=2-3 for 60 minutes, separating the insoluble residue from productive solution, crystallization of REE concentrate in the form of sulphates by bringing productive solution to a supersaturated state for rare earth metals increase in the concentration of sulfuric acid to >30% at a temperature of 20-80°C. the Crystallization of sulfates REM carried out preferably in the presence of the seed of them at W: T not more than 100 within of 0.4-3 hours Extraction of rare-earth metals in the concentrate is in the range of 50-60%. The REM concentrate is separated by filtration from the mother ~ 30%-aqueous solution NS, one part of which is used for decomposition of Apatite concentrate, and the other after water dilution to 20-25% H2SO4- turnover for the leaching of REE from phosphogypsum.

The disadvantages of the method are a significant number of technological operations leaching of REE, their increased duration. The method for extracting rare-earth metals from phosphogypsum (EN 2167105 C1, Lokshin AP and others, 20.05.2001), including portions of the sulfuric acid leaching, separation of mother liquor from the solid phase and its reuse for leaching the new portions of phosphogypsum, water wash the insoluble residue with the use of the leaching solution during leaching. While leaching of REE from the first portion of the phosphogypsum produced 2-6%solution of sulfuric acid at W:T=2-3. When the leaching of each subsequent portion of phosphogypsum concentration of sulfuric acid in the leaching solution increases according to the given ratio. The leaching solution is used at least three times, and the maximum concentration of sulfuric acid in the leaching solution is 24%. Before leaching phosphogypsum is crushed to particle sizes of 100 microns. This way you can reach 4-5 stages batch leaching on average, 32,65-38,68%REM extract from phosphogypsum.

The disadvantages of the method are the multistage process of leaching of REE, the need is clear to control and regulate (maintain) the desired ratio, and relatively low extraction of REE from phosphogypsum in solution.

The method for extracting rare earth elements from phosphogypsum (EN 2293781 C1, Lokshin AP and others, 20.02.2007), according to which the phosphogypsum is treated with a solution of sulfuric acid with a concentration of 22-30 wt.% if F:T=1.8 to 2.2 V for 20-30 minutes with the extraction of rare earth elements and sodium in solution, preventing with such duration of the process of spontaneous crystallizes the th REE of the leaching solution to separate it from the insoluble residue. After separation of the insoluble residue in the solution increases the degree of supersaturation of its rare earths by ensuring that the concentration of sodium in the range of 0.4-1.2 g/l with assistance, mainly sulfate or sodium carbonate.

The disadvantages of this method are the lack of an efficient technical solutions for the exception of a significant loss of rare earth elements contained in the wet insoluble residue and preparing it for disposal and accumulation of impurities in the products of the process.

The known method of phosphogypsum processing is partially washed postopera, consisting mainly of bassanite 2CaSO4·H2O (see, Lokshin EP, Kalinnikov V.T. Physico-chemical assessment and development of environmentally appropriate technologies for extraction of lanthanides from postopera. // Build the foundations of the modern strategies of natural resource management in the Euro-Asian region. Apatity: KSC RAS, 2005, S-269). Leaching of REE spend 26%solution of sulfuric acid at W:T=1.8 to 2.2 V for 20-25 minutes the resulting slurry for a period of not more than 5 minutes and filtered on a productive solution containing sulfates of rare-earth metals and insoluble residue.

From the pregnant solution crystallized double sulfates of rare-earth metals and sodium for 2 h at ensuring the concentration of sodium in the range of 0.4-1.2 g/l with the help of Na 2SO4(or Na2CO3), or lanthanides, for example, cerium sulfate. The resulting crystals of the double sulphates NaLn(SO4)2·H2O, how concentrate ∑ REE, separated by filtration from the sulfuric acid mother liquor, ≥98.3% of the volume of which is sent to the turnover on stage sulfuric acid leaching of REE, and 1.7% of the volume in the production of wet-process phosphoric acid (EPA).

The insoluble residue is washed with water on the filter and after neutralization with limestone taken to the dump, and the washing solution containing REE, directed to the production of EPA. Further processing of the concentrate of double sulfates of rare-earth metals and sodium is carried out by conversion to carbonates REM with soda, which regenerate.

The disadvantages of this method are the output from a process in the production of EPA at least 10% leached REM with a wash water insoluble residue of phosphogypsum and from 1.7% productive solution, which reduces the degree of extraction of ∑ REE in the concentrate, as well as the direction of the insoluble residue is not for recycling, and in the dump.

A known method of processing of phosphogypsum containing phosphorus compounds and lanthanide (EN 2337879 C1, Lokshin AP and others, 10.11.2008). The method includes the leaching of phosphorus and rare earth metal sulfate solution (in particular, 22-30%solution of H2SO4the a period of 20-25 minutes) to obtain supersaturated by lanthanides productive leaching solution and the insoluble residue. The selection of lanthanide concentrate of solution leaching is carried out by crystallization of the double sulphates of lanthanides and sodium while keeping sulfuric acid solution for at least 2 hours Control was obtained mother liquor of the crystallization is carried out at the value of the works of the content of phosphorus in solution and sludge moisture gypsum. Purification of the mother liquor from the phosphorus is carried out by introducing compounds of titanium (monohydrate titanylsulphate TiOSO4·H2On dry or 60%solution in 34%sulfuric acid solution).

The disadvantages of this method are significant (not less than 10%) loss of rare-earth metals with wet (20%) with deposits of gypsum (insoluble residue), expanding the range of reagents used - titanium compounds, and their regeneration will require the appropriate cost of chemical reagents and accessories, will complicate the process. In addition, the relatively high content of titanium in the sent to the step of leaching the mother solution crystallization (0,67 g/l in terms of TiO2) leads to wasteful consumption of titanium.

The method for extracting rare-earth metals from phosphogypsum (EN 2416654 C1, SOC NV and others, 20.04.2011), including its hillshade from phosphorus water carried out in a closed cycle, followed him at what elisala by passing a washing solution through the layer of carbonaceous waste (chalk) and return (turnover) depleted in phosphorus water in the washing cycle of phosphogypsum. From washed phosphogypsum lead leaching of rare earth metals with solutions of sulfuric acid at a concentration from 3 to 250 g/l mode heap leaching. The leaching solution adsorb rare earth metal cation exchanger, was stripped of their solution of ammonium nitrate to produce commodity regenerate (decorate) and return with reverse cycle leaching depleted in REE metals sulfate mother liquor sorption.

The disadvantages of this method are very low filtration rate of water at wash phosphogypsum from phosphorus, as well as leaching solutions through the layer of phosphogypsum equal 0,00036 cm/s (~30 cm per day). This causes a large (multi-day), the duration of these processes, high (≥10) ratio W:T, loss of rare-earth metals with water washing phosphogypsum from phosphorus, which account for about 3% (SOC NV, et al. solid waste phosphogypsum. // New approaches in chemical engineering practice and processes of sorption and extraction. Materials of the conference: St. Petersburg, 2011, Pp. 80-83). These deficiencies significantly reduce the technical and economic indicators.

Closest to the patented method is a method of phosphogypsum processing applied to FDG and PPG (see Lokshin EP, Kalinnikov V.T., Tareeva O.A. Extraction of rare earth is a separate estimate of industrial products and industrial waste Khibiny Apatite concentrate. // Non-ferrous metals. 2012. No. 3. P.75-80 - prototype). The way predusmatrivaet leaching of REE by filtering 1-5%solutions of sulfuric acid through the layer of phosphogypsum with getting the leaching solution and the insoluble residue ("purified phosphogypsum"). The insoluble residue is neutralized (in particular, using caso3and in the form of gypsum sent for recycling.

From the leaching solution containing in addition to REM and a number of impurities including phosphorus, fluorine, sodium) extract REE sorption on sulfoxides the cation exchanger in the H+or NH4+forms.

With saturated cation exchange resin to produce desorption REM solutions of ammonium sulfate with getting decorate with a concentration of REE, reaching 5 g/l in terms of ∑ (REM)2About3. From decorativ precipitated with NH4OH or ammonium carbonate concentrates in the form accordingly (REM)(OH)3or (REM)2(CO3)3. The content of oxides of rare-earth metals in the dried concentrate is more than 40%. Formed during the precipitation of REE concentrates the solution of ammonium sulfate can be reused for desorption REM.

Accumulating sulfate in the mother solution sorption of REE phosphorus and fluorine is removed from the technological process by their precipitation in the form of poorly soluble compounds. After filtering the resulting precipitation sent for recycling,and the aqueous phase (filtrate) - into circulation on stage leaching of REE.

Prototype method has several disadvantages:

1. Significant (multi-day) duration of the leaching process, REM, due to very slow infiltration rate (infiltration) sulfate solutions through a layer of phosphogypsum. Thus, the speed of filtration of leach solution through a layer of phosphogypsum thickness of 1.5 m was only 1.25 m per 1 m per day (rational duration of the leaching process is not specified). However, it should be noted that according to the above-mentioned senior SOC NV with co-authors, the linear speed of filtering sulfuric acid solutions (pH=1,0-1,1) through the layer of phosphogypsum was only 0,00036 cm/s, or ~0.3 m/day. In this case, as follows from table 3 of the article, in the leaching of REE in the filtering mode sulfate solution through a layer of phosphogypsum, removing the REM is about 30% with respect to W:T=3. Leaching same ~40% of REM required a significant ratio W:T, is equal to ~5.5V.

2. The need to use significant earth's surface for playgrounds filtration (percolation, heap) leaching of REE, given the very low specific filtering ability of phosphogypsum, and therefore are small in the height of the layer. There is the difficulty of laying phosphogypsum on site leaching, especially HRA is image in the dumps, as well as neutralization of insoluble residue (gypsum), in particular, limestone before disposing of it.

3. Sorbed cation exchange resin together with rare-earth metals calcium, iron, aluminum and other cations impurities, passing by desorption in desorbed, lower quality of REE concentrate. Desorption REM solutions containing only salt of mineral acid, it is not possible to the extent necessary to remove from the phase of the cation formed therein precipitation of REE phosphates and impurities, which reduces the degree of desorption of REM and purification of cation impurities.

The invention aims to remedy these disadvantages and improve the efficient recovery of REE from phosphogypsum.

The method of phosphogypsum processing includes leaching of REE from raw materials 1-5%solution of sulfuric acid to obtain a leaching solution containing rare-earth metals, phosphorus and fluorine, calcium, aluminum, iron and other impurities, sorption of REE from the leaching solution by cation exchange resin, followed by the separation of saturated REE cation from the mother liquor sorption, desorption REM from the cation exchanger desorbers solution in a known manner with getting dealbata, deposition of decorate of REM concentrate, separating the resulting slurry by filtration to concentrate REE and the mother liquor, which is used for desorption of REM, the return of the cation exchanger after desorption REM stage sorption precipitation of phosphorus, fluorine and other impurities from the mother liquor sorption of REE, filtering the resulting slurry to obtain phosphorus - and fluorine-containing sludge and a filtrate, which is used as recycled water.

The method differs in that the leaching of REE from phosphogypsum and sorption from solution leaching lead jointly by mixing the cation exchange resin with the slurry formed by mixing the feedstock with sulfuric acid, after which the resulting slurry filtered through the strainer with the Department of saturated REE cation exchange resin, then filtered slurry to obtain the insoluble residue and the mother liquor sorption and desorption rich REE cation process part of decorate.

The method can be characterized by the fact that leaching of REE from phosphogypsum and sorption from solution leaching is carried out at T:W=1:(2-3), and the fact that leaching of REE from phosphogypsum and sorption from solution leaching is carried out at the concentration of sulfuric acid in the leaching solution is equal to 2-3%.

The method may be characterized, in addition, the fact that leaching of REE from phosphogypsum and sorption from solution leaching lead for 60-300 minutes

The method can be characterized by the fact that leaching of REE from phosphogypsum and sorption from solution leaching is carried out at a counter-current movement of the pulp and cation exchange resin in which ascade apparatus, equipped with a mesh filter to separate the cation exchange resin from the pulp at a given number of cation exchanger in the apparatus, and also to the fact that leaching of REE from phosphogypsum and sorption from solution leaching is carried out at the loading of the cation in the amount of 0.5-5.0% of the volume of the pulp in the machine.

The method can be characterized and the fact that as the apparatus use-type reactor "pacuk", as a cation exchanger, use of strongly acidic sulfonation gel structure marks KU-2-8h or its analogs, preferably in the N+or NH4+- forms. To handle a busy REE cation exchanger using a 0.3-0.5 volume of decorate. As salts of sulfuric acid using ammonium sulfate.

The method can be characterized also by the fact that during the precipitation of REE concentrate from dealbata use of a substance selected from the group consisting of ammonia, ammonia water, carbonic acid salts of ammonium or alkali metals, or mixtures thereof.

The method can be characterized and the fact that the deposition of phosphorus and fluorine from the mother liquor sorption of REE are the basic calcium compound at a pH value equal to or greater than 5.5 and preferably with air stirring, and also the fact that as the primary calcium use limestone or quicklime or slaked lime, or a mixture thereof.

Technical result the person is to simplify the processing of phosphogypsum, reduced leaching and sorption of REE, improving the efficiency of cation exchange processes of sorption and desorption, and the quality of the concentrate ∑ REE in ensuring rational degree of extraction of REE from phosphogypsum.

The drawing shows a process flow diagram of processing by the patented method.

The method is as follows.

Waste phosphogypsum mixed with 1-5% solution of sulfuric acid. In the resulting slurry type cation exchange resin and carry out the mixing of the formed mixture for several hours at room temperature. When this occurs the simultaneous leaching of REE in leaching solution (aqueous phase of the pulp) and cation exchange sorption of it REM. It is advisable to use type reactor "pacuk". Together with REM in leaching solution (aqueous phase of the pulp into a number of related impurities (P, F, Al, Fe, kremachoclet and others), from which the phosphorus and fluorine are limited when disposing of insoluble residue (gypsum).

At the end joint of the sulfuric acid leaching and cation exchange sorption of the cation exchange resin is separated from the mother of the pulp in the strainer, then filtering the slurry to obtain the insoluble residue (gypsum) and the mother liquor sorption.

Wet insoluble residue is treated with the basic compound of calcium, preferably finely ground limestone to its subsequent disposal in a known manner. The mother liquor sorption clear of phosphorus, fluorine and other related impurities (Al, Fe, kremachoclet and others) by processing its basic calcium compound to pH≈5,8 with their transfer into the sediment when the purification rate in the range of 75-90%.

The processing of the mother liquor sorption is carried out at an air mixing, which allows at the specified pH to oxidize oxygen principal amount of ferrous iron to ferric iron and to highlight it in the hydroxide precipitate. From the resulting pulp allocate the precipitate by filtration to its utilization in a known manner. The purified mother liquor is used as recycled water.

Rich rare earth metal cation prior to desorption from it REM process part of dealbata order to Considine REE cation exchange resin with simultaneous desorption (preemptive) from him sorbed impurities (CA, Al, and others). This allows the subsequent desorption increase in decorate concentration of REE and reduce it to the impurity concentration, which leads to improvement of the quality of REE concentrate. Desorption of REM with the cation exchanger carried out in a known manner with a solution containing a salt of a mineral acid, preferably at a temperature of 50-60°C.

The mother liquor after Donatist what I cation exchanger is used at the stage of joint sulfuric acid leaching and sorption of REE and/or for the preparation of Stripping solution.

The achievement of the technical result proved the following examples.

Example 1. 200 g of waste phosphogypsum long-term storage (5 months) containing, wt.%: 0,44 ∑ REE; 1,R; 0,05 Na; 0,31 Raobs., 0,35 F is mixed with 600 cm33%-aqueous solution of sulfuric acid, add in obtained with respect to T:W=1:3 slurry of 15 cm3swollen (or ~7 g) strongly acidic sulfonic cation exchanger gel patterns KU-2-8h in NH4+form, which is ~2% of the volume of the pulp, and carried out under stirring, the formed mixture for 300 min at normal (room) temperature simultaneous translation (leaching) of rare-earth metals in the leaching solution (aqueous phase of the pulp) and cation exchange sorption of it REM.

Extraction of REE in the cation of the phosphogypsum is ~59%. Together with REM in leaching solution (aqueous phase of the pulp into a number of related impurities (P, F, Al, Fe, kremachoclet and others), from which the phosphorus and fluorine are limited when disposing of insoluble residue (gypsum).

At the end joint of the sulfuric acid leaching and cation exchange sorption of REE is separated from the pulp in the strainer cation exchange resin saturated REM to ~74 g/kg (33 g/l), and then filtering the slurry to obtain the insoluble residue (gypsum) and the mother liquor sorption concentration REM 9 mg/L.

Insoluble is th residue, with humidity ~23% and containing 0,34% R, 0,12% F is treated with finely ground limestone to a pH≈5.5 for its subsequent disposal in a known manner.

The mother liquor sorption clear of phosphorus, fluorine and other related impurities (Al, Fe, crimecity and others) by treating it with lime to pH≈5,8 with their transfer into the sediment when the purification rate in the range of 75-90%.

The processing of the mother liquor sorption of lead in air stirring. This allows at the specified pH to oxidize oxygen principal amount of ferrous iron to ferric iron and to highlight it in the hydroxide precipitate. From the resulting pulp allocate the precipitate by filtration to its utilization in a known manner, and purified mother liquor for use as recycled water for making pulp of phosphogypsum and/or original sulfuric acid leach solution.

Rich rare earth metal cation prior to desorption from it REM process part of decorate, component 0,3 its volume content in decorate 11.4 g/l ∑ REE with the aim of Considine cation exchanger REM with simultaneous desorption (preemptive) from him sorbed impurities (CA, Al, and others). This allows the subsequent desorption of REM increase in decorate concentration of REE and reduce it to the impurity concentration, which leads to improvement of the quality of the VA REE concentrate.

The mother liquor after Considine cation exchanger is used for sulfuric acid leaching and/or preparation of Stripping solution.

From the cation exchanger, considenng REM to ~103 g/kg, is desorbed by treatment of the cation exchanger, preferably at a temperature of ~50-60°C desorbers solution in the amount of 60 cm3containing ~200 g/l of ammonium sulfate, which is added sulfuric acid to a concentration of 30 g/L. thus the volume ratio of cation: deformirujuschij solution is 1:4, what is the concentration of REE in decorate about 11 g/l (including partial transition of REM in desorbed in the form of dispersions of double sulphates).

Consistency cation REM and their desorption spend (in columns) in ascending mode filtering respectively decorate and Stripping solution through a compacted layer of cation exchange resin.

Part of decorate - 0,3 its size (18 cm3- should be directed to the stage of Considine REE cation exchanger, while the remaining 0.7 volume decorate (42 cm3) precipitated concentrate REM using, in particular, ammonia. The content of ∑ REE in concentrate is after washing and drying of about 62%.

Example 2. The process is conducted in accordance with the conditions of example 1.

The difference is that the ratio of T:W=1: 2, the concentration of sulfuric acid in the leaching solution is ~5%, and the duration of the n conjunction leaching and sorption of REE by mixing sulfuric acid phosphogypsum slurry with 15 cm (~7 g) cation exchange resin is 60 minutes

At the end of the process of joint leaching and sorption of REE receive a cation exchanger, and the mother liquor of the pulp with the content of ∑ REE respectively 73,4 g/kg 0,012 g/l In the insoluble residue contains 0.35% of the P2O5and 0.10% F. removing the ∑ REE from phosphogypsum is 58,4%.

The content of REE in consystem the cation exchanger is ~102 g/l, the Content of REM decorate is 11.4 g/l, and in concentrate 60,3%.

Example 3. The process is conducted in accordance with the conditions of example 1.

The difference is that the sulfuric acid concentration in the leach solution is ~1%, and for Considine cation exchanger REM use 0.4 volume decorate.

At the end of the process of joint leaching and sorption of REE receive the cation exchanger and the mother liquor of the pulp with the content of ∑ REE, respectively: ~71.5 kg and 0.008 g/l In the insoluble residue contains ~0,41% P2O5and 0.14% F.

Removing ∑ REE of phosphogypsum in the concentrate is ~57%. The content of REE in consystem the cation exchanger is ~116 g/kg

The content of ∑ REE in decorate is 13.1 g/l, and concentrate ~64%.

From the above examples, a patented process ensures the achievement of the technical result and allows you to:

- To increase the recovery of REE from phosphogypsum through the process of leaching from the pulp through more effective (intensive) AG is treated as distinct from long-term percolation (filtering) leach solution through the layer (a lot) of phosphogypsum, which is characterized by the channeling of the solution and pereosazhdeniya sulfates REM.

To simplify the process of extracting rare-earth metals from phosphogypsum through collaborative leaching and sorption of REE. This also improves the manufacturability of the conclusion of the process the insoluble residue from the filter compared to removing it after percolation (heap leaching).

- Reduce the duration of REM extract from phosphogypsum, because leaching of REE in the method prototype is at a very low speed percolation leach solution.

- In addition, the joint leaching and sorption of REE can accelerate the process of transition from REM phosphogypsum in solution due to their sorption and shift, thus, the reaction equilibrium towards the formation of compounds of rare-earth metals contained in the phosphogypsum.

By Considine cation exchanger REM to decarbonate (expelling from it the appropriate amount of impurities and thereby improve not only the content of REE in commodity decorate, but also to improve the quality of concentrate ∑ REE.

1. The method of processing of phosphogypsum, including leaching of rare earth metals (REM) of phosphogypsum 1-5%solution of sulfuric acid to obtain a solution leaching, sorption of REE from the leaching solution by cation exchange resin, followed by the separation of saturated REE cation from the mother what about the solution, sorption, desorption REM from the cation exchanger desorbers solution with obtaining decorate, deposition of decorate of REM concentrate, separating the resulting slurry by filtration to obtain a concentrate of REM and the mother liquor, which is used for desorption of REM, the return of the cation exchanger after desorption REM stage sorption, precipitation of phosphorus and fluorine from the mother liquor sorption of REE, filtering the resulting slurry to obtain phosphorus - and fluorine-containing sludge and a filtrate, which is used as a circulating water PA stage leaching, characterized in that the leaching of REE from phosphogypsum and sorption from solution leaching lead jointly by mixing the cation exchange resin with the slurry formed when the mixture of phosphogypsum with a solution of sulfuric acid, after which the pulp is filtered through the strainer with the Department of saturated REE cation exchange resin, then filtered slurry to obtain the insoluble residue and the mother liquor sorption and desorption REM rich REE cation process part of decorate.

2. The method according to claim 1, characterized in that the leaching of REE from phosphogypsum and sorption from solution leaching is carried out at T:W=1:(2-3).

3. The method according to claim 1, characterized in that the REE leaching and sorption from solution leaching is carried out at the concentration of sulfuric acid in the solution wimalasiri is, equal to 1-3%.

4. The method according to claim 1, characterized in that the leaching of REE from phosphogypsum and sorption from solution leaching lead for 60-300 minutes

5. The method according to claim 1, characterized in that the leaching of REE from phosphogypsum and sorption from solution leaching is carried out at a counter-current movement of the pulp and of the cation in the cascade of apparatus, provided with a mesh filter to separate the cation exchange resin from the pulp at a given number of cation exchanger in the apparatus.

6. The method according to claim 5, characterized in that the leaching of REE from phosphogypsum and sorption from solution leaching is carried out at the loading of the cation in the amount of 0.5-5.0% of the volume of the pulp in the machine.

7. The method according to claim 5 or 6, characterized in that in an apparatus using a reactor of the type "pacuk".

8. The method according to claim 1, characterized in that the cation use of strongly acidic sulfonation gel structure marks KU-2-8h or its analogs, preferably in the H+or NH4+forms.

9. The method according to claim 1, characterized in that to handle a busy REE cation exchanger using a 0.3-0.5 volume of decorate.

10. The method according to claim 1, characterized in that during the deposition of REE concentrate from dealbata use of a substance selected from the group consisting of ammonia, ammonia water, carbonic acid salts of ammonium or alkali metals, or mixtures thereof.

11. The method according to claim 1, characterized in that the deposition of phosphorus and fluorine from the mother liquor sorption of rare-earth metals are calcium compound at a pH value equal or greater to 5.5, and preferably with air stirring.

12. The method according to claim 11, characterized in that calcium use limestone or quicklime or slaked lime, or a mixture thereof.



 

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SUBSTANCE: 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.

EFFECT: quite high selectivity by scandium and efficient separation of scandium and yttrium with their joint existence in a solution.

2 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to hydrometallurgical processing of mineral material, particularly scandium-containing "tailings" obtained during beneficiation of titanium-magnetite ore by wet magnetic separation. The method of extracting scandium is three-step sulphuric acid leaching of scandium, wherein at the first step, leaching is carried out with recycled solution after extraction of scandium at temperature of 30-50°C and solid to liquid ratio of 1:6-7 for 3-4 hours; the pulp is then divided into a solid phase and a liquid phase; at the second step, a portion of the solution obtained from the first step is returned to the solid phase and sulphuric acid is added to concentration of 340-360 g/l and sodium fluoride is added in amount of 20-25 kg fluorine/t solid; leaching is carried out at temperature of 95-98°C and solid to liquid ratio of 1:2.5-3 for 3-4 hours; further, at the third step, the pulp is diluted in solid to liquid ratio of 1:6.5-7.5; treatment is carried out at temperature of 95-98°C for 3-4 hours.

EFFECT: invention increases extraction of scandium, cuts the overall duration of the leaching process and consumption of sulphuric acid and sodium fluoride.

3 ex, 1 tbl

FIELD: metallurgy.

SUBSTANCE: proposed method comprises sulfuric acid leaching of scandium from red mud, pulp filtration, scandium sorption from sulfuric acid solutions, desorption from organic phase by carbonate solution to obtain column effluent. Then, scandium poorly soluble compounds are precipitated from column effluent, precipitate is filtered out, flushed, dried and annealed to get scandium-bearing concentrate. Note here that said leaching is performed by 10.0-13.5%-sulfuric acid at pulp initial vibration cavitation at rotary velocity of 35-60 m/s for 15-35 min. Scandium is precipitated from column effluent by potassium caprinate in amount of 75-100 g/t of scandium at pH 3.5-4.5 and exposure for 15-25 min.

EFFECT: increased yield.

3 cl, 2 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: proposed method comprises extraction of rare-earth metal cations by organic phase including extragent solution in inert diluter. Naphthenic acid is used as said extragent. Kerosene is used as inert diluter. Extraction is conducted in three stages at relationship between organic and aqueous phases O:A=1·(9-11) at every stage. Note here that, at first stage, europium cations (III) are extracted at content of naphthenic acid in kerosene of 10-13 vol. % and aqueous solution pH 5.0-5.1. At second stage, samarium cations (III) are extracted at content of naphthenic acid in kerosene of 13-16 vol. % and aqueous solution pH 4.6-4.7. At third stage cerium and lanthanum cations (III) are extracted at the same content of extragent and pH 5.0-5.1.

EFFECT: higher yield.

4 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: method of extracting rare-earth metals from solutions containing iron (III) and aluminium comprises sorption of rare-earth metals on sorbent. Ampholyte with iminodiacetic functional groups is used as said sorbent. Sorption is carried out after preliminary neutralisation or acidification of solution to pH 4-5 by whatever alkaline or acid agent to add ampholyte in obtained pulp with separation of solid fraction. Sorption is conducted at ampholyte:pulp ratio of 1:50-1:150, phase contact time of 3-6 h and in the presence of reducing agent.

EFFECT: higher selectivity.

5 tbl, 5 ex

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

FIELD: metallurgy.

SUBSTANCE: 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 Na2Ocaustic 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.

EFFECT: simplified process, higher yield of scandium oxide.

1 ex

FIELD: metallurgy.

SUBSTANCE: 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.

EFFECT: increased extent of europium (III) extraction.

2 dwg

FIELD: metallurgy.

SUBSTANCE: extraction method of gold from ores and products of their processing involves preparation of pulp of crushed initial raw material, alkalisation of prepared pulp till pH value is 9.5-10.0, sorption leaching of gold with weak-basic anion-exchange resin from alkalised pulp containing sodium cyanide. Then, by means of separation of saturated anion-exchange resin there performed is gold resaturation of saturated anion-exchange resin with separation of resaturated anion-exchange resin and mother solution. After resaturation is completed, gold desorption is performed by means of a solution containing 25-30 g/l of sodium cyanide and 3-4 g/l of sodium hydroxide so that demetallised anion-exchange resin and marketable strippant is obtained. Some part of marketable strippant is supplied for gold resaturation stage of saturated anion-exchange resin, demetallised anion-exchange resin and some part of mother solution is supplied for stage of sorption leaching of gold, and the other part of mother solution is supplied for preparation of desorbing solution.

EFFECT: increase in capacity of saturated weak-basic anion-exchange resin as to gold and reduction of gold losses on natural sorbents; considerable reduction of content of impurities in marketable strippant; shortening of duration of cyanide leaching of gold from ore raw material without reduction of extraction degree of gold to a solution.

9 cl, 1 dwg, 4 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: method involves treatment of rock with a sodium cyanide solution with formation of dispersion of rock particles with gold compound in the form of Na[Au(CN)2], which is dissolved in it. Then, particles are removed from the dispersion so that clarified solution of gold compound is obtained. Clarified solution contacts a solid zinc source so that their products are obtained as a result of reactions of ionic exchange and replacement in the form of water solution of zinc compound Na2[Zn(CN)4] and solid phase of gold. Solid phase of gold is separated and processed so that metal gold is obtained. As zinc source there used are particles of zinc hydroxide consisting of a composite sorbent dispersed in water, consisting of cellulose fibres with particles of zinc hydroxide, which are immobilised with them at their chemical deposition. Solid phase of gold is extracted in the form of its hydroxide.

EFFECT: accelerating and simplifying the process.

4 cl, 3 ex

FIELD: metallurgy.

SUBSTANCE: method involves use of an unbalanced solution consisting of a solution from the washing process of anionite from the acid and filtrate from the filter press, and their removal from the process together with a mother solution from deposition of natural uranium concentrate through an additional saturation operation together with a marketable reclaimed product. For that purpose, the plant includes a local solution recirculation circuit in the form of a collector for solutions of unbalanced and mother concentrate from deposition, which is connected to pipelines of the above solutions and equipped with solution supply pipelines attaching the collector through a gravity tank to an additional saturation column from the marketable reclaimed product and to a solution return pipeline attaching the gravity tank to the solution collector of the local solution recirculation circuit.

EFFECT: reduction of nitrate ions emissions; reduction of prime cost of end product and compliance with strict environmental requirements.

2 cl, 2 dwg, 1 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: extraction line of precious metals from cyanide solutions and/or pulps as per a coal-absorption technology includes a plant for metal sorption from solutions and/or pulps, a plant of secondary metal concentration, a plant for metal desorption and a plant of electrolytic metal extraction, which are installed in the technological process flow and connected to each other via transport pipelines. In addition, the line includes the plant for secondary metal concentration, which is arranged before the metal desorption plant. Besides, the secondary metal concentration plant with a pipeline of rich eluate is connected to the outlet as to eluate of the metal desorption plant, and with the coal feeding system it is connected to the input as to coal of the metal desorption plant. The metal desorption plant is connected through the plant for electrolytic metal extraction to the plant for secondary metal concentration with a transportation pipeline of poor eluates, and with a waste coal transportation pipeline it is connected to the plant for metal sorption from solutions and/or pulps.

EFFECT: improving efficiency of the line at simultaneous reduction of power consumption.

6 cl, 6 dwg

FIELD: chemistry.

SUBSTANCE: composition contains a compound of formula (I)

as a complexing component, where R is a C1-C12 alkyl, in percentage content of 1-99%, and the rest of the polymer matrix is a macroporous spherical granular copolymer of styrene with divinyl benzene LPS-500 with granule size of 40-200 mcm.

EFFECT: high sorption capacity with respect to Mo-99.

2 dwg

FIELD: metallurgy.

SUBSTANCE: proposed method comprises sulfuric acid leaching of scandium from red mud, pulp filtration, scandium sorption from sulfuric acid solutions, desorption from organic phase by carbonate solution to obtain column effluent. Then, scandium poorly soluble compounds are precipitated from column effluent, precipitate is filtered out, flushed, dried and annealed to get scandium-bearing concentrate. Note here that said leaching is performed by 10.0-13.5%-sulfuric acid at pulp initial vibration cavitation at rotary velocity of 35-60 m/s for 15-35 min. Scandium is precipitated from column effluent by potassium caprinate in amount of 75-100 g/t of scandium at pH 3.5-4.5 and exposure for 15-25 min.

EFFECT: increased yield.

3 cl, 2 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: method of extracting rare-earth metals from solutions containing iron (III) and aluminium comprises sorption of rare-earth metals on sorbent. Ampholyte with iminodiacetic functional groups is used as said sorbent. Sorption is carried out after preliminary neutralisation or acidification of solution to pH 4-5 by whatever alkaline or acid agent to add ampholyte in obtained pulp with separation of solid fraction. Sorption is conducted at ampholyte:pulp ratio of 1:50-1:150, phase contact time of 3-6 h and in the presence of reducing agent.

EFFECT: higher selectivity.

5 tbl, 5 ex

FIELD: metallurgy.

SUBSTANCE: proposed method involves conversion of platinum metals to actively sorbed sulphate-chloride form and sorption on strong-basic anion-exchange resin. At that, sulphate solutions of platinum and rhodium, which were prepared in advance and exposed during three months, are subject to conversion of platinum metals to active sorbed form by adding to them of a hydrogen chloride acid. Sorption is performed under dynamic conditions from obtained solutions on anion-exchange resin Purolite A-500, which contains tetradic ammonium base as a functional group with further desorption in two stages. At the first stage, solution 2M NaNO3 is passed through anion-exchange resin to extract platinum, and at the second stage, solution 2 M HCl is passed through the above anion-exchange resin to extract rhodium. The method does not require any additional regeneration of a sorbent and is environmentally safe.

EFFECT: simplifying and cheapening both the conversion method of sulphate forms of platinum metals to chloride metals, and the extraction and separation process of platinum and rhodium in freshly prepared and old solutions.

2 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: 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.

EFFECT: high efficiency of the method owing to higher extraction of rare-earth elements without a filtration step.

6 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: 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.

EFFECT: increasing REM extraction degree to finished product.

5 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. In order to obtain titanium dioxide, a mixture is prepared, leaching is carried out in sulphuric acid solution to form titanyl sulphate TiOSO4 and iron sulphates FeSO4 and Fe2(SO4)3, followed by precipitation of iron sulphate FeSO4 and hydrolysis of titanyl sulphate TiOSO4 to obtain hydrated titanium dioxide TiO(OH)2 and firing. The mixture is formed by adding potassium hydrogen sulphate KHSO4. Before leaching, the obtained mixture is melted at temperature of 300-400°C to obtain a melt containing potassium titanate K2TiO3. The melt is then leached using sulphuric acid solution with concentration of 5-10%.

EFFECT: invention enables to reduce concentration of sulphuric acid used when leaching and prolongs the service life of process equipment.

3 cl, 2 ex

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