Phosphosemihydrate processing method. RU patent 2507276.
 Method for opening loparite concentrates / 2506333Invention 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. |
 Method of processing phosphogypsum / 2504593Method 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. |
 Plasma-carbon production method of rare-earth metals, and device for its implementation / 2499848Method 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. |
 Cerium extraction method / 2495147Cerium 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. |
 Method of extraction of rich components from production solutions for processing of black-shale ores / 2493279Method 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. |
 Processing method of black-shale ores / 2493273Processing 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. |
 Processing method of black-shale ores with rare metals extracting / 2493272Processing 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. |
 Method of extracting rare-earth metals (rem) from phosphogypsum / 2492255Proposed 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. |
 Method of extracting rare-earth metals from phosphogypsum / 2491362Method 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. |
| Method for quantitative determination of cerium in steels and alloys / 2491361 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. |
| Method of processing phosphogypsum / 2504593 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. |
| Processing method of black-shale ores / 2493273 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. |
| Processing method of black-shale ores with rare metals extracting / 2493272 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. |
| Method of extracting rare-earth metals (rem) from phosphogypsum / 2492255 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. |
| Method of extracting rare-earth metals from phosphogypsum / 2491362 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. |
| Method of producing titanium dioxide / 2487836 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%. |
 Method for extraction of uranium from ores / 2485193Method involves leaching of uranium and iron using sulphuric acid solution and ferric iron contained in the ore as an oxidiser. After leaching is completed, uranium is extracted from the solution so that mother solution containing ferrous iron is obtained. Then, acidification of the mother solution is performed using sulphuric acid and recovery of ferric iron is performed by oxidation of ferrous iron so that a reusable solution is obtained, and recirculation of that solution for leaching of uranium is performed. Recovery of ferric iron is performed by action on the mother solution of high-voltage pulse electric discharges at high voltage pulse amplitude of not less than 10 kV and at pulse repetition cycle at the interval of 400÷1400 pulse/sec. At that, prior to action on mother solution with high-voltage pulse electric discharges, it is subject to dispersion. |
 Nickel matte processing method / 2485190Method involves leaching of matte using a nickel solution at increased pressure and temperature so that nickel sulphate solution is obtained. Nickel sulphate solution is cleaned from impurities of iron, copper and cobalt, and nickel is extracted by means of electrowinning from clean solution of nickel sulphate so that cathode nickel and sulphuric anolyte containing nickel sulphate and sulphuric acid is obtained. Sulphuric anolyte is subject to extraction treatment using a mixture of tertiary amines and aliphatic alcohols as an extracting agent with extraction to the extract of sulphuric acid and obtainment of sulphuric raffinate and extract. Sulphuric acid is re-extracted with water from the extract, and sulphuric raffinate is supplied to leaching of the matte. |
| Method of producing scandium-bearing concentrate from red mud / 2484164 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. |
 Method of extracting manganese from manganese-bearing raw stock / 2484161Method of processing manganese oxide materials containing heterovalent manganese oxides comprises leaching crushed raw stock by sulfuric acid aqueous solution in the presence of bivalent iron sulphate, iron precipitation and manganese extraction from productional solution. Note here that said leaching is performed on adding reducing agent in the form of metal iron or iron sulphate (Fe2+) at 60-95°C for 60-300 min. Leaching is carried out at initial concentration of H2SO4 in leaching solution of up to 100 g/dm3 and final acidity in productional solution relative to hydrogen ion exponent pH<2. |
 Method for reprocessing of metal sulfide-containing products / 2245380Invention relates to reprocessing of metal sulfide-containing ores, products and waste of ore concentrating and metallurgy industry. Method includes leaching in sulfuric acid solution with concentration of 1.8-35 g/dm3 at 0-1500C in presence of iron(III) ions with concentration more than 1 g/dm3 and iron regeneration using element compounds having built-in voltage when transition from highest valence to lowest one higher the same of iron. Compounds are added into solution when increasing iron(II) ion concentration. Method is useful in leaching by bawl, percolation, heap, and underground processes, as well as in metal recovering into solution, development of rare and noble metals, impregnated in metal sulfides. Invention affords the ability to reduce power requirement, increase effectiveness of equipment utilization, and decrease reagent consumption. |
FIELD: metallurgy.
SUBSTANCE: 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.
EFFECT: method provides improvement of REE extraction efficiency.
6 cl, 4 ex
The invention relates to the technology of complex processing of phosphogypsum, in particular during sulphate fertilizers production of Apatite concentrate, and can be used to produce concentrate of rare earth elements (REE), as well as gypsum product suitable for the production of building materials and cement.
When the sulphuric processing of the Khibiny Apatite concentrate for mineral fertilizers is formed cross-pit spreader phosphogypsum, which contains a significant amount of REE. Major Russian companies: JSC «Ammofos», JSC «Balakovo mineral fertilizers JSC «Voskresensk mineral fertilizers, processing Khibiny Apatite concentrate by sulfuric acid method is used, or only technology with obtaining a dump of phosphogypsum as (FPG)or and technology of obtaining dump phosphogypsum as figs and (FDG). The generated figs and FDG, as a rule, are stored together. To ensure a high REE extraction of it should be kept in conditions blade for at least 2 months, which reduces the efficiency of phosphogypsum processing due to the increased use of masking a calcium-containing reagent need to unnecessary operations of loading-unloading, transportation, crushing and grinding, as figs when storing enters and seizes, forming strong enough pieces.
There is a method of phosphogypsum processing (see Pat. 2416654 of the Russian Federation, the IPC C22B 59/00, 3/04 (2006.01), 2011), including the water leaching layer dump phosphogypsum, phosphorus and REE waged a vicious cycle to ensure pH 2 with the translation of phosphorus into the solution and its further disposal by passing through the layer of carbonate departing and returning purified from phosphorus mortar into a revolving cycle of washing phosphogypsum. Then spend the leaching of phosphogypsum solution of sulfuric acid with a concentration of 250 g/l (22,5%Mas.) with the transfer of REE and residual phosphorus leaching solution and receipt of phosphogypsum with a low content of phosphorus, which is treated with lime milk with production of construction plaster. REE from the leach solution is extracted by sorption on with the formation of depleted by REE sulphate solution, which is used in circulation. Desorption REE of cation exchanger was lead by treatment solution of ammonium nitrate with obtaining , which is treated with gaseous ammonia. Sediment hydroxides of rare-earth elements is separated from the solution and dried with obtaining the rare-metal concentrate containing rare-earth elements 60%.
The disadvantages of this method include the fact that the method does not allow for the extraction of phosphogypsum fluoride and sodium, and is applicable only for processing of phosphogypsum with a low content of such impurities. Method is also characterized by an increased concentration of sulphuric acid and significant flow of calcium required not only for the selection of phosphorus from the wash water, but also to neutralize the acid solution present in after acid leaching. Furthermore, the method is applicable to extract REE only of phosphogypsum, stored in dumps.
Known also adopted as a prototype method for processing (see Lokshin .., V.T. Kalinnikov, O.A. Extraction of rare earth elements of industrial products and industrial waste Khibiny Apatite concentrate Tsvet. 2012. №3. P.76-77.), which leached by passing sulfate solution with a concentration of not less than 2,5-3 wt.% through a layer of with the speed of filtration 1.25 m 3 1 m 2 a day, with the transfer of REE and extrinsic components, including phosphorus, fluorine and thorium, in the solution of leaching and getting busy sulfuric acid solution layer purified with a low content of impurity component. Neutralization of sulfuric acid saturated solution produce calcium weighing reagent in the form of calcium carbonate with obtaining gypsum product, and extraction of REE and extrinsic components of the solution sorption leaching is performed using cation and education depleted sulphate solution, which is used in circulation. After the saturation of cation carry out desorption from it REE and extrinsic components by treatment with a solution of ammonium salt obtaining . Deposition of REE and extrinsic components of the produce introduction hydroxide or ammonium carbonate with the Department of or carbonate sediment REE. From the pre- within 2 months JSC «Ammofos», which contained 0,56 wt.% REE, 4 wt.% acid to 76.8% of REE.
The disadvantage of this method is the impossibility of its application for processing . In the known method does not solve the problem of separation of thorium extracted from rare earth elements, which results in obtaining the rare-earth concentrates with increased radioactivity. In addition, after leaching blended sulfuric acid solution, which requires the increased use of calcium-containing reagent addressing it.
The present invention is directed to achievement of the technical result, which consists in increasing the efficiency of the method by recycling and reduction of consumption of calcium-containing reagent with the provision of high quality gypsum product and a high degree of extraction of rare earth in a non-radioactive rare earth concentrate.
The technical result is achieved by the method of processing , including leaching by passing a solution of sulfuric acid with a concentration of not less than 3% by weight through a layer with translation of REE and extrinsic components, including phosphorus, fluorine and thorium in the solution of leaching and obtaining layer with a low content of impurity components, saturated sulfuric acid solution, neutralization calcium weighing reagent to form gypsum product, removing REE and extrinsic components of the leach solution sorption using cation and education depleted sulphate solution, which is used in circulation, desorption REE and extrinsic components of a busy cation exchanger by treatment solution ammonium sulphate with obtaining , deposition of REE and extrinsic components of the precipitator and the sludge separation of REE, according to the invention, use , prior to leaching perform its processing aqueous solution containing not less than 4.9 g/l of fluoride-ion, leaching conducted at W:T is not less than 2.5:1 preemptive and branch containing fluoride ion water solution after leaching produce displacement of residual quantity of water solution of sulfuric acid with a volumetric flow of water, in generally equal to the volume of the residual amount of sulphate solution, with getting washed and leach solution, neutralization lead after the ousting of the residual amount of solution of sulfuric acid, and precipitator is injected into in two stages, with the first stage to ensure the pH of 4.5-5.0 with settling and separation sediment, and the second stage - up to ensure that the pH of not less than 7 deposition and the Department of REE concentrate.
Achieving the technical result is driven by the fact that the processing of aqueous solution, prior to leaching lead for 6-8 hours at a flow rate of the solution of 0.37-0,41 l on 1 kg .
The achievement of a technical result also contributes to the fact that as a source of fluorine-ion use the ammonium fluoride or sodium.
Achieving the technical result is also that as a source of fluorine-ion use contained in , which activate introduced in aqueous solution hydroxide or with ammonium carbonate in quantity 0,67 mol ammonium cation 1 fluorine atom.
To achieve a technical result is also that leaching lead acid with a concentration of 3 6 wt.%.
To achieve a technical result is directed also, that as precipitator, use ammonia gas or a mixture of carbon dioxide in the molar ratio of 2:1.
The essence of the claimed process consists in the following. In rare earth elements are present mainly in the form of self-phase - hydrated REE phosphates TrPO 4 ·h 2 o the Value of «x» depends on the temperature of doing process, which is different in various enterprises. Usually shot from a vertical filters () Fig Russian factories value «x» is less than unity. Such REE phosphates at room temperature, it is difficult soluble in solutions of mineral acids. We found that the increase in the efficiency of leaching REE from PPG is due to the use of hydrated REE phosphates TrPO 4 ·xH 2 O x<1 in fluorides of rare earth elements. Solubility of fluorides of rare earth in sulfuric acid solutions is large enough and do not limit leaching REE from figs.
The transition in fluorides determined by the occurrence of a hydrolysis anion
S i F 6 2 -according to the reactions:
Na 2 SiF 6 + 2H 2 O = embed SiO 2 + 4HF + 2NaF , (1) K 2 SiF 6 + 2H 2 O = embed SiO 2 + 4HF + 2KF (2)with the formation of free fluorine-ion battery, which then interacts with by hydrated REE phosphates:
TrPO 4 Buna x H 2 O + 3F - = embed TrF 3 + ÐO 4 3- + x H 2 O ,ãäå õ
< 1 (3) .Processing layer aqueous solution before leaching is conducted at a flow rate of the solution of 0.37-0,41 l on 1 kg . The content of fluorine-ion in aqueous solution, in the amount not less than 4.9 g/l reduces the time of reaction (3) to 6-8 hours. Fluoride ion can be obtained not only by the introduction of fluorides of ammonium or of sodium, but also by strengthening the hydrolysis contained in figs in sufficient quantities ion
S i F 6 2 -by processing Fig solution of an alkaline reagent in the form hydroxide or ammonium carbonate, quantity 0,67 mol ammonium cation 1 fluorine atom.
Leaching produce a solution of sulfuric acid with concentration 3 6 wt.% when W:T is not less than 2.5:1 preemptive and branch containing fluoride ion aqueous solution. After leaching produce displacement of residual quantity of water solution of sulfuric acid, containing rare-earth elements, with a volumetric flow of water, generally equal to the volume of the residual amount of sulphate solution, with getting washed and leach solution. Neutralization calcium weighing reagent in the form of hydrated or quicklime with obtaining gypsum product lead after the ousting of the residual amount of sulfuric acid. The use of dilute solutions of sulfuric acid (3-6 wt.%) allows for efficient leaching REE from , as well as retrieve and insert them cation exchange resin from the leach solution with a high degree of usage of the sorption capacity of the sorbent. The resulting depleted sulphuric acid solution and use in circulation.
Desorption of REE and extrinsic components of a busy cation lead by treatment with concentrated solution of ammonium sulfate, which provides a high degree of desorption cations REE and thorium. Deposition of REE and thorium from produce gaseous ammonia or a mixture of carbon dioxide in the molar ratio of 2:1. Use precipitator in gaseous form creates the possibility of smooth adjustment of the pH-value in the whole volume of . Precipitator is injected into in two stages, the first stage after reaching a pH of 4.5-5.0 formed sediment, and the second stage - after reaching the pH of not less than 7 precipitates or carbonaceous concentrate REE.
The essential features of the claimed invention to determine the scope of legal protection and sufficient for obtaining a technical result of the above, perform the functions and correlate with the results as follows.
Use allows its effective recycling, reducing the time required to activate leaching REE from in 180-240 time, excluding the preliminary two-month stay on the spoil.
Processing prior to leaching with water solution containing not less than 4.9 g/l of fluoride-ion battery provides stimulating REE with their transfer into in sulfuric acid form. The concentration of fluoride-ion less than 4.9 g/l may be insufficient to ensure the completeness of the reaction (3).
Conduct leaching solution of sulphuric acid in W:T is not less than 2.5:1 preemptive and branch containing fluoride ion aqueous solution ensures, on the one hand, higher recovery REE from layer in solution of leaching, and on the other hand, high efficiency of their subsequent sorption on . The decrease in G:T less than 2.5:1 leads to a significant reduction of extraction of rare earth elements in the solution.
The ousting of residual quantity of water solution of sulfuric acid after leaching with a volumetric flow of water, generally equal to the volume of the residual amount of sulphate solution, with getting washed and leach solution provides a complete recovery containing REE sulphate solution of the layer . It may also induce a decrease in the consumption of calcium-containing reagent to neutralize contained in phospho- sulfuric acid to ensure a high degree of extraction of rare earth elements. With less volumetric flow of water't ensures completeness of the removal of contained sulphate solution. The increase in water consumption does not give additional positive result.
Neutralised calcium weighing reagent washed after the water displacement of the residual amount of solution of sulfuric acid helps reduce the neutralizing agent and provides gypsum product, the relevant technical requirements. As the calcium-containing reagent is preferable to use slaked or quicklime.
Introduction precipitator in in two stages to ensure first pH of 4.5-5.0 allows the first stage quantitatively translate into sediment thorium, while not less than 99.9% REE remains in solution. With the further increase of the pH to 7.0 to 7.5 REE deposited in a non-radioactive concentrate, while calcium remains in solution.
The totality of the above features is necessary and sufficient to obtain a technical result of the invention lies in the processing and reducing the consumption of calcium-containing reagent with the provision of high quality gypsum product and a high degree of extraction of rare earth elements with getting their non-radioactive concentrates that in General, increases the efficiency of a method.
In particular cases, the implementation of an invention is preferable following operations and operational parameters.
Processing before leaching with fluoride water solution for 6-8 hours at a flow rate of the solution of 0.37-0,41 l on 1 kg translates REE in sulfuric acid form. Processing time aqueous solution of less than 6 hours is not enough to ensure the completeness of the translation of REE in form. Increase the processing time for more than 8 hours increases the duration of the process without achieve additional benefits. The amount of fluoro aqueous solution is determined by the volume of the pore space in the layer . The solution expense less 0,37 l on 1 kg is insufficient to process the entire layer and the consumption of more 0,41 l is redundant.
Use as a source of fluorine-ion fluoride ammonium or of sodium determined by their sufficient water solubility, and the possibility of their associated production at the sulphuric processing of the Khibiny Apatite concentrate.
Possibility to use as a source of fluorine-ion contained in , which activate introduced in aqueous solution hydroxide or with ammonium carbonate in quantity 0,67 mol ammonium cation 1 fluorine atom is determined by the fact that the freshly obtained different plants fluoride content is 0.25-0.4% and if this fluorine transfer of form to the form of fluoride-ion battery using the reactions (1), (2), it will be enough to ensure the completeness of the reaction (3). Consumption of alkaline reagent less than 0.67 mol ammonium cation 1 fluorine atom does not ensure the completeness of reactions (1), (2), and more than 0,67 mol leads to irrational use of reagents.
Leaching solution of sulfuric acid with concentration 3 6 wt.% ensures, on the one hand, higher recovery REE from layer in the leaching solution, and the other hand, high efficiency of their subsequent sorption . Decrease in concentration of sulphuric acid than 3% by weight reduces extraction of rare earth in solution leaching from , and increasing the concentration of more than 6 wt.% although activates leaching REE from , but considerably complicates further sorption REE .
Use as precipitator gaseous ammonia allows to receive hydroxide molding boxes concentrates of rare-earth elements, and the use of the mixture of carbon dioxide in the molar ratio of 2:1 - carbonate concentrates REE.
The above private features of the invention shall allow a method in optimal regime from the point of view of effective processing at reducing the consumption of calcium-containing reagent, ensuring a high quality of gypsum product and achieving a high degree of extraction of rare earth in a non-radioactive concentrates.
The essence of the proposed method can be illustrated by the following examples.
Example 1. 3.6 kg , contains, mass%: ΣTr 2 O 3 - 0,574, P 2 O 5 - 1,31, F - 0,30, ThO 2 - 0.0015 and Na 2 O - 0.26 and formed as a layer, treated for 8 hours 1,476 l of water solution (0,41 l on 1 kg )containing 10,13 g/l fluoride ammonium NH 4 F (5,2 g/l of fluoride-ion). Then leaching is carried out by passing through the layer of a solution of a sulfuric acid displacement of 12.6 l with a concentration of 3 wt.% (W:T=3,5:1) preemptive and the Department of 1,476 l fluoro aqueous solution, containing in g/l: P 2 O 5 - 16,17, ΣTr 2 O 3 - 0,345, Na 2 O - 2,9, ThO 2 - 1,4·10 -4 , H 2 SO 4 - 2.6, F - 6,97.
After leaching produce displacement of residual quantity of solution of sulfuric acid with water, with a volumetric flow of water 1,476 l, that is the volume of the residual amount of sulphate solution with getting washed and leach solution. Extraction of rare earth in the solution obtained leaching was 76,74%. Solution leaching in the amount of 12.6 l concentration g/l: H 2 SO 4 - 27,6, P 2 O 5 - 2,71, ΣTr 2 O 3 - 1,258, Na 2 O - 0,147, ThO 2 - 3,86·10 -3 and F - 1,09 sent for sorption extraction of rare earth elements.
The washed contains in terms CaSO 4 , wt.%: P 2 O 5 - 0,32, including water-soluble less than 0.01, F - is not detected, ThO 2 - 0,00015, water soluble Na 2 O - less than 0.001 free H 2 SO 4 of not more than 0.06. Impurities content of phosphorus, fluorine, water-soluble sodium and radionuclides are washed allow its use for the production of gypsum construction materials and cement. Perform neutralization washed to pH 6 by processing calcium weighing reagent in the form of slaked lime Ca(OH) 2, with its consumption of 2 g per 1 kg of . After at 200 degrees C receive plaster brand G5 (GOST 125-79).
Removing REE from the solution leaching is performed using KU-2-8 with obtaining of 12.6 l depleted sulphate solution, containing in g/l: P 2 O 5 - 2,71, ΣTr 2 O 3 not more than 0.001, Na 2 O - 0,073, ThO 2 - 7,3·10-5 and F - 1,09 that sulfuric acid up to 3 wt.% and sent for leaching. The degree of sorption REE from the solution was 99,92%), CHU 2 98,1%. Then carry out a desorption REE by processing a busy 2.5 l ammonium sulfate solution (NH 4 ) 2 SO 4 with a concentration of 300 g/L. The degree of desorption REE amounted to 99.3%, thorium - 99,5%. In the received in the amount of 2.4 l introduce gaseous ammonia to ensure pH 4.5 with settling and separation sediment, and then to pH 7 to settling and separation REE concentrate. Removing REE and thorium from in sediment amounted to, respectively, 0.05, and 95.4 percent. Removing REE from in concentrate containing in terms of the amount of anhydrous oxides of not less than 60 wt.% the amount of oxides of REE, amounted to 99.9%. Removing REE from in concentrate equal to 76,04%. Contents ThO 2 relative to the amount of oxides REE was about 0,014% that corresponds to the effective specific radioactivity And eff about 450 Bq/kg, i.e. concentrate REE belongs to class I of materials (eff ≤740 Bq/kg), handling production conditions is carried out without any restrictions.
Example 2. 3.6 kg , contains, mass%: ΣTr 2 O 3 - 0,574, P 2 O 5 - 1,31, F - 0,30, ThO 2 - 0.0015 and Na 2 O - 0.26 and formed as a layer, process within 6 hours of 1.33 l of water solution (0,37 l on 1 kg )containing 10,83 g/l sodium fluoride NaF (4.9 g/l of fluoride-ion). Then leaching is carried out by passing through the layer of a solution of a sulfuric acid in volume 9 l with a concentration of 4 wt.% (W:T=2,5:1) preemptive and the Department of 1.33 l fluoro aqueous solution, containing in g/l: P 2 O 5 - 20,05, ΣTr 2 O 3 - 0,035, Na 2 O - 7,58, ThO 2 - 2·10 -4 , H 2 SO 4 - 0,6, F - 5,77.
After leaching produce displacement of residual quantity of solution of sulfuric acid water with a volumetric flow of water 1,33 l, that is the volume of the residual amount of sulphate solution with getting washed and leach solution. Extraction of rare earth in leaching solution was 72,28%. Solution leaching in the amount of 9.0 l concentration g/l: H 2 SO 4 - 36,75, P 2 O 5 - 0,94, ΣTr 2 O 3 - 1,66, Na 2 O - 0,70, ThO 2 - 5,52·10 -3 and F - 1,07 sent for sorption extraction of rare earth elements.
The washed contains in terms CaSO 4 , wt.%: P 2 O 5 - 0,33, including water-soluble less than 0.01, F - is not detected, ThO 2 - 0,00011, water soluble Na 2 O - less than 0.001 free H 2 SO 4 - 0,07. Impurities content of phosphorus, fluorine, water-soluble sodium and radionuclides are washed allow its use for the production of gypsum construction materials and cement. Perform neutralization washed to pH 6 by processing calcium weighing reagent in the form of slaked lime Ca(OH) 2 expenditure 2,5 g per 1 kg . After at 200 degrees C receive plaster brand G5 (GOST 125-79).
Removing REE from the solution leaching is performed using KU-2-8 obtaining 9 l depleted sulphate solution, containing in g/l: R 2 0 5 - 0,94, ΣTr 2 O 3 not more than 0.001, Na 2 O - 0,26, ThO 2 - 9,4·10-5 and F - 1.07, and that sulfuric acid up to 4 wt.% and sent for leaching. The degree of sorption REE from the solution was 99.94 per cent), ThO 2 - 98,3%. Then carry out a desorption REE by processing a busy 2.5 l ammonium sulfate solution (NH 4 ) 2 SO 4 with the concentration of 280 g/L. the Degree of desorption REE amounted to 99.4 per cent, thorium - 99,5%. In the received in the amount of 2.45 l introduce gaseous ammonia to ensure pH 5 to settling and separation sediment, and then to pH 7.1 deposition and Department REE concentrate. Removing REE and thorium from in sediment grew, respectively, by 0,07 and 95.8%. Removing REE from in concentrate containing in terms of the amount of anhydrous oxides of not less than 60 wt.% the amount of oxides of REE, amounted to 99.9%. Removing REE from in concentrate equal to 71,75%. The content of the CHU 2 relative to the amount of oxides REE was about to 0.014 wt.%), that corresponds to the effective specific radioactivity And eff about 450 Bq/kg, i.e. concentrate REE belongs to class I of materials (eff ≤740 Bq/kg), handling production conditions is carried out without any restrictions.
After leaching produce displacement of residual quantity of solution of sulfuric acid water with a volumetric flow of water 1,476 l, that is the volume of the residual amount of sulphate solution with getting washed and leach solution. Extraction of rare earth in the solution obtained leaching was 69,54%. Solution leaching in the amount of 10.8 l concentration g/l: H 2 SO 4 - 46,55, P 2 O 5 - 1,26, ΣTr 2 O 3 - 1,33, Na 2 O - 0,372, ThO 2 - 3,95·10 -3 and F - 0,704 sent for sorption extraction of rare earth elements.
The washed contains in terms CaSO 4 , wt.%: P 2 O 5 - 0,31, including water-soluble less than 0.01, F - is not detected, ThO 2 - 0,00032, water soluble Na 2 O - less than 0.001 free H 2 SO 4 - 0,08. Impurities content of phosphorus, fluorine, water-soluble sodium and radionuclides are washed allow its use for the production of gypsum construction materials and cement. Perform neutralization washed to pH 6 by processing calcium-containing reagent in the form of quicklime CaO expenditure 2.4 g per 1 kg of . After at 200 degrees C receive plaster brand G5 (GOST 125-79).
Removing REE from the solution leaching is performed using cationite KU-2-8 obtaining 10.8 l depleted sulphate solution, containing in g/l: P 2 O 5 - 1,26, ΣTr 2 O 3 - 0,002, Na 2 O - 0,22, ThO 2 - 7,9·10-5 and F - 0,704 that sulfuric acid up to 5 wt.% and sent for leaching. The degree of sorption REE from the solution was 99,85%, ThO 2 - 98%. Then carry out a desorption REE by processing a busy 2.5 l ammonium sulfate solution (NH 4 ) 2 SO 4 with a concentration of 250 g/L. the Degree of desorption REE amounted to 99.3%, thorium - 99,2%. In the received in the amount of 2.45 l introduce gaseous ammonia to ensure pH 5 to settling and separation sediment, and then to pH of 7.2 to settling and separation REE concentrate. Removing REE and thorium from in sediment grew, respectively, by 0,09 and 95.6%. Removing REE from in concentrate containing in terms of the amount of anhydrous oxides of not less than 60 wt.% the amount of oxides of REE, amounted to 99.9%. Removing REE from in concentrate equal to 68,88%. The content of the CHU 2 relative to the amount of oxides REE was about 0,015% that corresponds to the effective specific radioactivity And eff about 480 Bq/kg, i.e. concentrate REE belongs to class I of materials (eff ≤740 Bq/kg), handling production conditions is carried out without any restrictions.
Example 4. 3.6 kg , contains, mass%: ΣTr 2 O 3 - 0,574, P 2 O 5 - 1,31, F - 0,3, ThO 2 - 0.0015 and Na 2 O - 0.26 and formed as a layer, treated for 8 hours 1,404 l of water solution (0,39 l on 1 kg ), containing 13 g/l (NH 4 ) 2 CO 3 , which corresponds to 0,67 moles of ammonium cation 1 fluorine atom. As a result of waking contained in , the content of fluorine-ion in the solution is 7.7 g/HP Then leaching is carried out by passing through a layer of a solution of sulfuric acid displacement 10.8 l with a concentration of 6 wt.% (W:T=3:1) preemptive and the Department of 1,404 l fluoro aqueous solution, containing in g/l: P 2 O 5 - 15,9, ΣTr 2 O 3 Of 0.133, Na 2 O - 4,05, ThO 2 - 3,1·10 -5 , H 2 SO 4 - 2.4, F - 2,4.
After leaching produce displacement of residual quantity of solution of sulfuric acid water with a volumetric flow of water 1,404 l, that is the volume of the residual amount of sulphate solution with getting washed and leach solution. Extraction of rare earth in leaching solution was 76,92%. Solution leaching in the amount of 10.8 l concentration g/l: H 2 SO 4 - 54,88, P 2 O 5 - 1,3, ΣTr 2 O 3 - 1,471, Na 2 O - 0,4, ThO 2 4,3·10 -3 and F - 0,69 sent for sorption extraction of rare earth elements.
The washed contains in terms CaSO 4 , wt.%: P 2 O 5 - 0,3, including water-soluble less than 0.01, F - is not detected, ThO 2 - 0,00021, water soluble Na 2 O - less than 0.001 free H 2 SO 4 - 0,11. Impurities content of phosphorus, fluorine, water-soluble sodium and radionuclides are washed allow its use for the production of gypsum construction materials and cement. Perform neutralization washed to pH 6 by processing calcium weighing reagent in the form of quicklime CaO expenditure 3.3 g on 1 kg . After at 200 degrees C receive plaster brand G5 (GOST 125-79).
Removing REE from the solution leaching is performed using cationite KU-2-8 obtaining 10.8 l depleted sulphate solution, containing in g/l: P 2 O 5 - 1,3, ΣTr 2 O 3 - 0,003, Na 2 O - 0,25, ThO 2 - 1,5·10-4 and F - 0,69 that sulfuric acid up to 6 wt.% and sent for leaching. The degree of sorption REE of the solution is 99.8%, CHU 2 of 96.5%. Then carry out a desorption REE by processing a busy 2.5 l ammonium sulfate solution (NH 4 ) 2 SO 4 with a concentration of 300 g/L. The degree of desorption REE amounted to 99.5%, thorium - 99,2%. In the received in the amount of 2.45 l impose a mixture of gaseous ammonia and carbon dioxide in the molar ratio of 2:1 to ensure pH 5 to settling and separation sediment, and then to pH 7.1 deposition and the Department of carbonate REE concentrate. Removing REE and thorium from in sediment grew, respectively, by 0.1 and 95,7%. Removing REE from in carbonaceous concentrate containing in terms of the amount of anhydrous oxides of not less than 60 wt.% the amount of oxides of REE, amounted to 99.9%. Removing REE from in carbonaceous concentrate equal to 76.3%. Contents ThO 2 relative to the amount of oxides REE was about 0,015% that corresponds to the effective specific radioactivity And eff about 480 Bq/kg, i.e. carbonate concentrate REE belongs to class I of materials (eff ≤740 Bq/kg), handling production conditions is carried out without any restrictions.
From the above Examples, 1-4 shows that the proposed method in contrast to the prototype allows effectively to process to receive plaster with low content of impurities phosphorus, fluorine and water-soluble sodium, which allows its use for the production of gypsum construction materials and cement. Furthermore, the method can significantly (10.0-18,6 times) reduce the consumption of calcium-containing reagent, because the washed contains small amounts of sulfuric acid. Removing REE from in nonradioactive or carbonaceous concentrate reaches 76,3%. The method is relatively simple and could be implemented using standard equipment and available reagents.
1. Method for processing , including leaching by passing a solution of sulfuric acid with a concentration of not less than 3% by weight through a layer of with the translation of REE and extrinsic components, including phosphorus, fluorine and thorium, in the solution of leaching and obtaining layer with a low content of impurity components saturated sulfuric acid solution, neutralization calcium weighing reagent to form gypsum product, removing REE and extrinsic components of the leach solution sorption using cation and education depleted sulphate solution, which is used in circulation, desorption REE and extrinsic components of a busy cation exchanger by treatment with a solution of ammonium sulfate with obtaining , deposition of REE and extrinsic components of the precipitator and the sludge separation of rare earth, wherein the process , prior to leaching perform its processing aqueous solution containing not less than 4.9 g/l of fluoride-ion, leaching conducted at W:T is not less than 2.5:1 preemptive and branch containing fluoride ion water solution after leaching produce displacement of residual quantity of water solution of sulfuric acid with a volumetric flow of water equal to the volume of the residual amount of sulphate solution, with getting washed and leach solution, neutralization lead after displacement of residual quantity of solution of sulfuric acid, and precipitator is injected into in two stages, with the first stage to ensure the pH of 4.5-5.0 with settling and separation sediment, and the second stage - up to ensure a pH of at least 7 of deposition and the Department of REE concentrate.
2. The method according to claim 1, characterized in that the processing aqueous solution containing fluoride ion, prior to leaching are about 6-8 hours at a flow rate of the solution of 0.37-0,41 l on 1 kg .
3. The method according to claim 1 or 2, wherein that as a source of fluorine-ion use the ammonium fluoride or sodium.
4. The method according to claim 1 or 2, wherein that as a source of fluorine-ion use contained in , which activate introduced in aqueous solution hydroxide or with ammonium carbonate in quantity 0,67 mol ammonium cation 1 fluorine atom.
5. The method according to claim 1, characterized in that the leaching of lead acid with a concentration of 3 6 wt.%.
6. The method according to claim 1, characterized in that as precipitator use ammonia gas or a mixture of carbon dioxide in the molar ratio of 2:1.