Processing method of black-shale ores with rare metals extracting

FIELD: metallurgy.

SUBSTANCE: 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.

EFFECT: increasing break-down of ore and extraction of rare metals: vanadium, uranium, molybdenum and rare-earth elements, reducing consumption of acid and improving efficiency of autoclave volume usage.

1 tbl, 1 ex

 

The invention relates to pressure hydrometallurgy and can be used for extraction of rare metals from poor, hard, ultra-fine ores.

Attempts fundamental approach to the development of theoretical foundations and the creation of a method of complex extraction of rare metals (vanadium, uranium, molybdenum, rare earth elements) of black shale ores were numerous. The basis of the proposed methods was laid pyrometallurgical oxidation firing at temperatures of 750-850°C. the Disadvantage of pyrometallurgical methods is the burning of carbon, the formation of harmful gases and dust containing radioactive elements.

The known method of direct leaching of rare metals from raw materials in acid solutions, which use a variety of oxidizing agents and complexing agents (Palant AA Direct extraction of vanadium from magnetite concentrate. J. "Metals", No. 5, 1996). The introduction of oxidizing agents having a redox potential higher than +330 mV, allows you to oxidize the uranium, vanadium, molybdenum and iron in the higher oxidation States are well extracted synthetic resins or mineral sorbents. The difference in the chemical properties of anionic forms of uranium, vanadium, molybdenum and phosphorus is low and does not allow to achieve a clear separation of elements in one technology, it is logical method.

The method for extracting vanadium in the solution of the vanadium-containing material (Sat. "Chemistry and technology of vanadium compounds", Perm, Materials of the first all-Union conference on the chemistry, technology and application of vanadium compounds, 1974, s-108). The method includes annealing in atmospheric conditions at a temperature of 350-400°C vanadium raw materials with solid sulfamethizole additives Fe (+III) and sulphate of ammonia and leaching of calcine solutions of sulfuric acid.

The known method (patent RF №2148669, IPC SW 34/22, publ. 10.05.2000,) in which the oxidative roasting of raw materials lead in atmospheric conditions at a temperature of 150-350°C after wetting it with a solution of sulfuric acid and subsequent leaching with acid. The consumption of sulfuric acid on cycle support in stages: firing: leaching=(60-80):(20-40)%.

A common shortcoming of these methods of processing vanadium-containing raw materials is the increased consumption of reagents and low skrivemate vanadium minerals.

There is a method of processing products containing sulfides of metals (RF patent No. 2245380, IPC SW 3/08, publ. 27.01.2005 g), consisting in the implementation of the leaching of processed products in sulfuric acid solution concentration of from 1.8 to 3.5 g/DM3at a temperature of from 0 to 150°C in the presence of ferric ions when the concentration of b is over 1 g/DM 3and regeneration of ferric carried out by the connection elements, the potentials of the transition from higher extent in the lower valence is higher than that of iron added to the solution by increasing the concentration of ions of bivalent iron.

The disadvantage of this method of processing is that when it is used due to the relatively "soft" conditions of leaching under atmospheric conditions is not achieved high recovery of valuable components, and that is permanent loss of sulfuric acid in the form of SO3 and SO2, leaving from the reaction zone into the environment.

The closest to the technical nature of the claimed invention is a method of processing quartzite Karatau, comprising leaching the ore with sulfuric acid solution to the dissolution of rare metals (provisional patents KZ No. 12431 A, IPC SW 34/22, SW 60/02, publ. 17.12.2002, bull. No. 12).

The disadvantage of this method is the low autopsy resistant minerals of rare metals.

The technical result of the invention is to increase the opening of valuable components (vanadium, uranium, molybdenum and rare earth elements), improving their retrieval.

The technical result is achieved in the method of processing black shale ores for the extraction of rare metals, comprising leaching the ore with a solution of sulfuric acid with restoregeometry metals, while the leaching of lead into the autoclave with a solution of sulfuric acid, consisting of free and bound sulfuric acid at a ratio of H2SO4(free):H2SO4(tie)=2:1, containing 25-45 g/l of ferric sulfate, 70-90 g/l of aluminum sulfate and 0.5 g/l of nitric acid at a temperature of 140-160°C, in the range of total concentration of H2SO4(General)equal 350-450 g/l, at a density of pulp T:W=1:0.7-0.9, preferably 1:0.8, the constant redox potential in the system is equal to Eh 350-450 mV, for 2-3 hours until the residual concentration of free H2SO4(free)within 45-75 g/L. in Addition, the leaching autoclave lead with pneumatic agitation under a pressure equal to 13.5-15 ATM and when the content of the above sulfate salts 220-320 g/l

It is established that a highly efficient extraction of valuable components from the black shale ores can be realized in conditions of autoclave leaching sulfuric acid solution of iron ions (+III), aluminum (+III), vanadium (+IV) and nitric acid under pressure. Only the application of pressure to 10-15 ATM., the temperature of 140-160°C, the total concentration of H2SO4in the range of 350-450 g/l at T:W=1:0.7-0.9, preferably 1:0.8, the constant redox potential in the system is equal to Eh 350-450 mV for 2-3 hours, allows you to increase the extraction of vanadium, etc the other valuable components in terms of the flow diagram of material flow and autoclave. These conditions result in partial dissolution and pereselenie solid phase with the formation of finely dispersed solid particles. When conducting the leaching less than 2 hours unable to oxidize Spinelli, and the duration of the process above 3 hours in oxygen atmosphere is the oxidation of vanadium to the highest degree of oxidation and its coprecipitation with jarosite. The free acid (H2SO4(free)independently introduced into the process, and is formed by hydrolysis of sulfate, iron, and destruction of sulfide minerals in the composition of the original ore. Maintaining the process temperature in the range 140-160°C allows you to get free sulfuric acid by oxidation of sulfide sulfur ore and hydrolysis of ferric sulfate with the formation of insoluble hematite and gypsite. Sulfuric acid concentration equal to 350-450 g/l, is the sum of free H2SO4(free)and related H2SO4(tie)when the ratio is 2:1. In conjunction with other distinctive features of this ratio acid allows to convert the vanadium in soluble form by the following reactions:

Al2O3+3H2SO4Al2(SO4 )3+3H2O(1)

The process of leaching by free and combined acids with a ratio of H2SO4(free):H2SO4(tie)=2:1 in the interval to the total concentration of H2SO4(total)equal 350-450 g/l, allows to achieve a sufficiently high recovery of valuable metals at a residual concentration of free sulfuric acid 45-75 g/l

When the reduction of H2SO4(free)less than 45 g/l is observed co-deposition of vanadium with insoluble compounds of iron. At a concentration of more than 75 g/l apparent excessive acid and reagents to neutralize productive solutions.

The recommended ratio of T:W=1:0.7-0.9, preferably 1:0.8 to allows you to get the pulp necessary mobility and high density up to 65% solid in comparison with a prototype suitable for the extraction of valuable components. When the ratio is less than 1 TJ:0.7 pulp poorly mixed, and if T:W more than 1:0.9 decreases the efficiency of the volume of the autoclave.

The redox potential of the system is supported by the elements, the potential of which is higher than that of iron, this potential is equal to Eh 350-450 mV and is a necessary and sufficient condition for the opening of valuable components.

Maintaining the concentration of the oxidizer ions Fe (+III), aluminum (+III) and vanadium (+IV), nitric acid and sulfur dioxide (SO3under the pressure of 10-15 bar, increases the speed and depth dissection of rare metals from CR # (oxides in lower oxidation States) and to reduce the time of the audit process.

The salt content includes sulfates of aluminum(+III), Fe(+III), vanadium(+IV) and free sulfuric acid. With this iron, vanadium and sulfuric anhydride provide oxidation process during leaching and iron sulphate is involved in the formation of free H2SO4(free). The upper limit of salinity 320 g/l is determined by the limit of solubility, and the bottom 220 g/l provides the necessary acidity in the leaching process.

The proposed method autoclave leaching provides efficient extraction of valuable components to the content in the sludge, %: V2O5-0.05, U-0.0004, Mo-0.001, REE-0.01), as well as to reduce the consumption of sulfuric acid in 2-2 .5 times in comparison with the prototype of the m by reducing losses to the atmosphere SO 3and SO2, hydrolysis of sulphate of iron and the oxidation of sulfide sulfur ore, which is involved in the process. Improving the efficiency of the volume of the autoclave is achieved by increasing the density of the pulp, providing effective leaching.

Example.

Autoclave leaching process is performed on decarbonising ore containing 0.57% V2O5, 0.02% U, 0.03% Mo 0.09% REE. The ore sample is 400 g, particle size 0.2 mm (100%)Nawasco get mixed up with a leaching solution containing 200 g/l H2SO4(free)and 0.5 g/l of nitric acid (HNO3) and 40 g/l of ferric sulfate and 90 g/l of aluminum sulfate at T:W=1:0.8. The slurry is loaded into the autoclave and lead the process at a temperature of 150°C, a pressure of 10 ATM. under stirring for 3 hours, and the ratio of H2SO4(free):H2SO4(tie)=2:1. At the end of the leaching process, the autoclave is cooled, the solution is filtered and the precipitate washed with a 3% solution of H2SO4and prototechno hot water in stage 2 of the calculation of T:W=1:1.

The results of the experiments are given in table.

1. A method of processing black shale ores for the extraction of rare metals, comprising leaching the ore with sulfuric acid solution to the dissolution of rare metals, characterized in that the leaching of lead into the autoclave with a solution of sulfuric acid consisting of free and bound sulfuric acid at a ratio of H 2SO4(free):H2SO4(tie)=2:1 and containing 25-45 g/l of ferric sulfate, 70-90 g/l of aluminum sulfate and 0.5 g/l of nitric acid, when the pressure in the autoclave 10-15 ATM with stirring at a temperature of 140-160°C, in the range of concentrations of total H2SO4(total)equal 350-450 g/l, at a density of pulp T:W=1:0.7 to 0.9, with a constant redox potential Eh in the system, equal 350-450 mV, for 2-3 hours until the residual concentration of free H2SO4(free)within 45-75 g/l

2. The method according to claim 1, characterized in that the autoclave leaching lead with pneumatic agitation under a pressure of 13.5-15 ATM.

3. The method according to claim 1, characterized in that the pressure leaching is carried out at the content of the above sulfate salts 220-320 g/L.



 

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1 tbl

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4 tbl, 4 ex

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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.

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3 cl, 2 tbl, 2 ex

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EFFECT: higher yield.

4 dwg, 1 ex

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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: invention can be used for extraction, concentration and cleaning of molybdenum from companion elements (Fe3+, Cu2+, Zn2+, Ni2+, Co2+, Al3+, Sn4+, Sb3+, rare-earth elements3+, etc.) at processing of different liquid and solid molybdenum-containing wastes and middling products. Extraction method of molybdenum from diluted acid solutions containing companion elements of molybdenum involves molybdenum deposition in the form of its salt. Besides, deposition with molybdenum purification is performed in the form of its cesium salt of 12-molybdophosphoric acid containing the following: Cs3-xHxPMo12O40·nH2O (x=0-1, n=9-12). Deposition is performed at heating up to 40-80°C by subsequent addition of orthophosphate-ion in the form of soluble phosphate or orthophosphoric acid, strong acid, for example sulphuric acid or sodium hydroxide up to pH 1-3 and soluble cesium salt, including mother solutions obtained during leaching of pollucite.

EFFECT: increasing extraction degree of molybdenum from process and effluent solutions.

2 dwg, 3 ex

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