RU2608117C1 - Method of processing solutions after carbonate opening of tungsten ore - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to a method of processing solutions after carbonate opening of tungsten ores. Method involves extraction of tungsten from a solution after leaching carbonate in an organic phase of an anionite, extraction of tungsten from anionite into aqueous productive solution to obtain ammonium paratungstate therefrom, returning solutions after extraction of tungsten for autoclave decomposition. Sorption is carried out on highly basic anionite AV-17-8 in chloride form. Ammonium paratungstate is processed to tungsten trioxide. Solution after extraction of tungsten is directed for crystallization of sodium chloride. Gases released during crystallisation and calcination of ammonium paratungstate are condensed and delivered for precipitation of sodium bicarbonate. Obtained precipitate is calcined to obtain sodium carbonate, which is directed for autoclave decomposition. Mother solution of sodium hydrocarbonate precipitation is heated to decomposition of carbonates, evaporated solution of ammonium chloride is directed for extraction of tungsten from anionite phase.

EFFECT: providing fire safety and closed cycle at on leaching reagent.

1 cl, 1 dwg, 1 ex

Description

The invention relates to hydrometallurgy of tungsten and can be used to obtain tungsten anhydride from solutions after soda leaching of tungsten concentrates.

A known method of processing solutions after carbonate opening of tungsten ores [Utkin N.I. Non-ferrous metallurgy. M .: Metallurgy. - 1985. S. 409-414], including the precipitation of artificial scheelite, its dissolution, followed by the precipitation of technical tungsten acid, dissolution of the acid in ammonia water, the allocation of ammonium paratungstate and calcination to tungsten trioxide.

The disadvantages of this method are the high cost of reagents at each stage of the redistribution and large volumes of acidic wastewater.

A known method of processing solutions of sodium tungstate [RU 2102326 C1, IPC6 C01G 41/00, C22B 34/36, publ. 01/20/1998], including the extraction of tungsten from acidic media with a salt of a quaternary ammonium base, followed by its reextraction with a solution of an inorganic reagent. The extraction is carried out using a salt of an organic acid and trialkylbenzylammonium as a quaternary ammonium base salt, and the solution is re-extracted with an ammonia solution.

The disadvantages of this method include the need for acidification of the solution and the fire hazard of organic solvents.

A known method of producing ammonium paratungstate [RU 2118668 C1, IPC6 C22B 34/36, C01G 41/00, publ. 09/10/1998] (prototype), including the concentration and purification of tungsten from impurities without acidification of autoclave liquors in the cycle "extraction from a solution after carbonate leaching into a phase of an organic anion exchanger - extraction from an anion exchanger phase into an aqueous productive solution", processing of productive solutions to obtain ammonium paratungstate , the return of the solutions after extraction of tungsten for autoclave decomposition.

The disadvantage of this method is that during sorption on anion exchangers, the carbonate ion also undergoes sorption, which reduces its concentration in the raffinate and, accordingly, breaks the cycle of the leaching reagent.

The objective of the present invention is to develop a method that allows you to abandon fire hazardous organic extractants and completely close the cycle of the leaching reagent.

The proposed method for processing solutions after the carbonate opening of tungsten ores as in the prototype includes the concentration and purification of tungsten from impurities without acidifying the autoclave liquors in the cycle "extraction from solution after carbonate leaching into the phase of organic anion exchange resin - extraction from the anion exchange resin into an aqueous productive solution" processing productive solutions to produce ammonium paratungstate; returning the solutions after extraction of tungsten for autoclave decomposition.

According to the invention, after carbonate opening of tungsten ores, sorption is carried out on the highly basic anion exchange resin AB-17-8 in chloride form. Ammonium paratungstate is processed to tungsten trioxide. The solution after extraction of tungsten in the anion exchange resin is sent to the crystallization of sodium chloride. The gases released during crystallization and calcination of ammonium paratungstate are condensed and sent to precipitate sodium bicarbonate. The resulting precipitate is calcined to obtain sodium carbonate, which is sent for autoclave decomposition, and the mother liquor of the precipitation of sodium bicarbonate is heated until the decomposition of carbonates. One stripped off solution of ammonium chloride is sent to extract tungsten from the anionite phase.

The use of highly basic anion exchange resin AB-17-8 (ion exchange resin) as anion exchange resin provides fire safety of the proposed method.

и вольфрамат

ионы:The carbonate phase passes into the phase of the anion exchange resin, which was initially charged into the Cl ^- form

and tungstate

ions:

2 [R ₄ N] Cl _org + Na ₂ WO _{4 water} → [R ₄ Ν] ₂ WO _4org + 2NaCl _water

2 [R ₄ N] Cl _org + Na ₂ CO _{3 water} → [R ₄ N] ₂ CO _3org + 2NaCl _water

A solution containing Na ⁺ - and Cl ^- ions is sent to the crystallization of NaCl. Ionite is fed to the stage of extraction from the anionite phase (desorption) with a solution of NH ₄ Cl, where it is charged into the Cl ^- form, after which it is suitable for a new stage of ion exchange.

[R ₄ N] ₂ WO _4org + 2NH ₄ Cl _water → (NH ₄ ) ₂ WO ₄ +2 [R ₄ N] Cl _org

[R ₄ N] ₂ CO _3org + 2NH ₄ Cl _water → (NH ₄ ) ₂ CO ₃ +2 [R ₄ N] Cl _org

A desorbate containing (NH ₄ ) ₂ CO ₃ and (NH ₄ ) ₂ WO ₄ is sent to the crystallization stage, where (NH ₄ ) ₂ WO ₄ , partially decomposing, passes into crystalline ammonium paratungstate (PVA). In this case, ammonium carbonate decomposes:

(NH ₄ ) ₂ CO ₃ ↔ 2NH ₃ + H ₂ O + CO ₂ .

The off-gases (NH ₃ , H ₂ O, CO ₂ ) are condensed to give a solution of ammonium carbonate. When annealing PVA, gaseous NH ₃ , H ₂ O are released, which are sent to the condensation of ammonium carbonate. The resulting solution of ammonium carbonate is sent to the precipitation stage of NaHCO ₃ : CO ₂ is bubbled through the solution and mixed with NaCl:

(NH ₄ ) ₂ CO ₃ + H ₂ O + CO ₂ → 2NH ₄ HCO ₃

NH ₄ HCO ₃ + NaCl → NH ₄ Cl + NaHCO ₃

The resulting NaHCO ₃ precipitate was filtered off and calcined:

NaHCO ₃ → Na ₂ CO ₃ + H ₂ O + CO ₂

The mother liquor of the NaHCO ₃ precipitation step containing (NH ₄ ) ₂ CO ₃ , NH ₄ HCO ₃ and NH ₄ Cl is heated, and carbonates decompose. The off-gas is sent to the condensation of (NH ₄ ) ₂ CO ₃ , one stripped off solution of NH ₄ Cl - to desorption of tungsten.

In this way, a cycle is closed by leaching reagent.

In FIG. 1 is a schematic flow diagram of the processing of solutions after carbonate opening of tungsten ores.

Example

A 500 ml sample obtained by soda autoclave leaching of a tungsten concentrate with a content of Na ₂ CO ₃ 220 g / l and Na ₂ WO ₄ 120 g / l was filtered on a vacuum filter and mixed with 3 dm ^{3 of} highly basic anion exchange resin AB-17-8 in chloride form . The raffinate was evaporated, the resulting saturated NaCl solution was sent to the NaHCO ₃ precipitation step. Desorption was carried out with 400 ml of a solution of NH ₄ Cl with a concentration of 360 g / l. Desorbate with a concentration of (NH ₄ ) ₂ WO ₄ 190 g / l and (NH ₄ ) ₂ CO ₃ 250 g / l was sent for PVA crystallization. 85% PVA (48 g) crystallized in one stage, the mother liquor was returned to the crystallization stage, and the resin was adsorbed. The off-gases (NH ₃ , H ₂ O, CO ₂ ) were condensed in a water-cooled condenser at 30 ° C. The resulting solution of (NH ₄ ) ₂ CO _{3 was} sent to precipitate NaHCO ₃ . Precipitation was carried out in an agitator with stirring and bubbling of air. Sparging was carried out using a low pressure compressor. As a precipitant, 190 ml of a NaCl solution with a concentration of 320 g / L was used. The resulting pulp was filtered, NaHCO ₃ crystals were sent for calcination in a muffle furnace at 150 ° C, after calcination, 80 g of Na ₂ CO ₃ were obtained; departing H ₂ O, CO ₂ sent to the stage of deposition of NaHCO ₃ . The filtrate was sent to a rotary evaporator to decompose (NH ₄ ) ₂ CO ₃ at 80 ° C. The NH ₃ , H ₂ O, CO ₂ released during this process were sent for condensation and return to the precipitation stage of NaHCO ₃ , and the stripped off NH ₄ Cl solution was desorbed.

After annealing PVA in a muffle furnace at 800 ° C, WO _{3 was} obtained, weighing 42.6 g. The degree of extraction of tungsten from the initial solution in one stage was 90%, while the remaining 10% was sent for crystallization with the next batch of desorbate.

Achieved technical result is a method for producing tungsten anhydride from carbonate solutions when the cycle is closed by leaching reagent.

Claims (1)

A method of processing solutions after the carbonate opening of tungsten ores by autoclave soda decomposition, including the extraction of tungsten from the solution by sorption into the phase of the organic anion exchange resin, the extraction of the anion exchange resin from the phase into the aqueous productive solution, preparation of ammonium paratungstate from the production solution, returning the solution after extraction of tungsten to autoclave decomposition, different that after the carbonate opening of tungsten ores, sorption of tungsten from the solution is carried out on the highly basic anion exchange resin AB-17-8 in chloride Orme, the solution, after extraction of tungsten to the anionite phase, is sent to crystallization of sodium chloride, ammonium paratungstate is calcined to tungsten trioxide, gases released during crystallization of sodium chloride and calcination of ammonium paratungstate are condensed and sent to precipitate sodium hydrogen carbonate, the resulting precipitate is calcined to obtain carbonate which is sent for autoclave decomposition, the mother liquor of the precipitation of sodium bicarbonate is heated to decomposition of carbonates, and one stripped off solution of chloride and ammonia is sent to extract tungsten from the anionite phase.

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