WO2015176429A1 - Method for extracting vanadium by leaching vanadium-containing raw material fired clinkers with ammonium bicarbonate solution - Google Patents

Abstract

A method for extracting vanadium by leaching vanadium-containing raw material fired clinkers with an ammonium bicarbonate solution, the method comprising: leaching vanadium-containing raw material fired clinkers with an ammonium bicarbonate solution to enable vanadium to enter the solution in the form of ammonium vanadate to obtain leached residue and a vanadium-containing solution; and a vanadium pentoxide product is obtained from the vanadium-containing solution via cooling, crystallization and separation of the ammonium vanadate and calcination of the ammonium vanadate. The method employs an ammonium bicarbonate solution leaching technology without sodium salts, has a simple process, is easy to operate, and has a vanadium extraction rate of 85-99% without producing saline waste water.

Description

Method for extracting vanadium by clinker carbon ammonium solution after roasting of vanadium-containing raw material Technical field

The invention belongs to the technical field of vanadium chemical metallurgy, and in particular relates to a method for extracting vanadium from a clinker carbon ammonium solution after calcination of a vanadium-containing raw material.

Background technique

Vanadium-titanium magnetite, vanadium slag, stone coal and other vanadium-containing raw materials The traditional vanadium extraction method is vanadium extraction by roasting-water immersion/acid leaching method. The vanadium-containing raw material sodium roasting-water leaching is the mainstream method for extracting vanadium. The basic principle of the sodium roasting process is to convert the low-valent vanadium in the vanadium-containing raw material into water-soluble five by high-temperature calcination (750-850 ° C) with sodium salt such as Na ₂ CO ₃ , NaCl, Na ₂ SO ₄ as an additive. The sodium salt of vanadium is directly immersed in the sodium calcined product to obtain a vanadium-containing leach solution, and then an ammonium salt is added to prepare ammonium vanadate precipitation, and the vanadium oxide product is obtained by reduction roasting. The recovery rate of vanadium in the sodium roasting process is low. The recovery rate of vanadium in a single roasting is about 70%. After repeated roasting, the recovery rate of vanadium is only 80%, and it needs to be calcined several times, and the energy consumption is high. During the roasting process. It will produce harmful HCl, Cl ₂ and other aggressive gases. The subsequent ammonia precipitation process will result in high salinity ammonia-containing wastewater. The ammonia-containing wastewater not only pollutes the environment, but also has a high cost of treatment.

In order to solve the problem of exhaust gas pollution in the sodium roasting process and the agglomeration of the charge due to the low melting point of the sodium salt, calcification roasting-acid leaching vanadium has been widely concerned as a relatively clean vanadium extraction process. The method uses lime, limestone, dolomite and other calcareous raw materials instead of sodium salt additives to carry out high temperature roasting of vanadium slag, convert vanadium into water-insoluble calcium vanadate, and then dilute with dilute acid, and vanadium in the leachate is hydrolyzed by vanadium. Or ion exchange recovery. This method has been applied industrially in the Tula ferrous metallurgical plant in the Soviet Union. In recent years, Pangang Group (patent CN 101161831A) has made progress in product impurity removal and purification, and completed the pilot test. Calcification roasting avoids chlorine/sulfur contamination of conventional sodium roasting, but vanadium conversion for calcification roasting is still less than 80% due to mass transfer barriers that are also limited by the calcination process.

CN 101899582A proposes a method for extracting vanadium pentoxide from vanadium slag. The vanadium slag is calcined at 800-1000 ° C, and the clinker is subjected to alkali leaching of 20 to 50% alkali concentration, and the vanadic acid is obtained by silicon removal and cooling crystallization. The sodium crystals are then converted to vanadium by vanadium, which is converted to acid and ammonium salts. The method has the problem that impurities are difficult to remove and difficult to filter, and the problem of acid ammonia nitrogen wastewater can not be avoided, and the vanadium recovery rate is less than 90%.

CN 1082617A proposes to treat the high-temperature vanadium slag obtained by blowing directly at 900-1300 ° C to promote the oxidation of low-valent vanadium in the slag into pentavalent vanadium. After the slag is cooled and crushed, at a certain temperature, alkali concentration, oxygen The vanadium in the slag is leached under partial pressure. The method does not need to be calcined at a high temperature after the vanadium slag is cooled down, the energy consumption is greatly reduced, and the environmental pollution caused by the sodium roasting is avoided, but the metal iron cannot be recovered, and the vanadium recovery rate is low. The problem.

At present, there is no report on the direct leaching of vanadium-containing raw materials for roasting clinker using ammonium bicarbonate solution.

Summary of the invention

In view of the deficiencies of the prior art, one of the objects of the present invention is to provide a method for leaching vanadium from a clinker-containing carbon ammonium solution after calcination of a vanadium-containing raw material. Compared with the existing roasting clinker leaching method, the vanadium leaching rate is high, the leaching temperature is low, the leaching conditions are mild, and other impurities in the vanadium-containing raw material do not enter the leachate, and subsequent ammonium vanadate separation is simple. Since the roasting process does not use sodium salt, the operation is easy to control, no harmful kiln gas is generated, and no salty wastewater is produced.

To achieve the above object, the present invention is achieved by the following technical solutions:

A method for leaching vanadium by clinker carbon ammonium solution after calcination of a vanadium-containing raw material, pulverizing the crust-containing raw material in a solution of vanadium in a solution of vanadium, and causing vanadium to enter the solution in the form of ammonium vanadate to obtain leaching slag and Vanadium solution. After the vanadium-containing raw material is calcined, the trivalent vanadium is converted into a leachable pentavalent vanadium during the roasting process, and the pentavalent vanadium can be reacted with the ammonium bicarbonate solution to form ammonium vanadate, thereby extracting the vanadium from the raw material.

As a preferred technical solution, in the method of the present invention, the vanadium-containing raw material is vanadium-titanium magnetite or stone. a mixture of one or more of coal, vanadium slag or a vanadium-containing catalyst; wherein the vanadium-containing catalyst may be a catalyst before use or a catalyst that cannot be reused after use;

According to a preferred embodiment of the present invention, the calcination is one or a combination of two or more of blank calcination (ie, no additive calcination) and calcification calcination.

As a preferred technical solution, in the method of the present invention, the ammonium bicarbonate solution refers to NH ₄ ⁺ /HCO ₃ ^- /OH ^- , NH ₄ ⁺ /CO ₃ ^2- /OH ^- or NH ₄ ⁺ /HCO ₃ ^- /CO ₃ ^2- /OH ^- solution, which means that it can be NH ₄ HCO ₃ solution, (NH ₄ ) ₂ CO ₃ solution, mixed solution of NH ₄ HCO ₃ and (NH ₄ ) ₂ CO ₃ , ammonia water and NH ₄ HCO A mixed solution of _3, a mixed solution of ammonia and (NH ₄ ) ₂ CO _{3 ,} a mixture of ammonia and NH ₄ HCO ₃ and (NH ₄ ) ₂ CO ₃ can also be obtained by carbonizing a CO ₂ gas in an ammonia water. .

As a preferred technical solution, in the method of the present invention, the concentration of the ammonium carbonate solution is determined by the molar concentration of each ion in the solution: the concentration of NH ₄ ⁺ is 0.5-6 mol/L, and the concentration of HCO ₃ ^- is 0.5-6 mol/L. The concentration of CO ₃ ^2- is 0.5-5 mol/L, which can be obtained by adding different solution combinations. When the concentration of NH ₄ ⁺ /HCO ₃ ^- /CO ₃ ^{2- in the} ammonium carbonate solution is less than 0.5mol/L, the extraction rate of vanadium is very low, and the concentration of NH ₄ ⁺ /HCO ₃ ^- is higher than 6mol/L, CO ₃ ^2- The concentration of vanadium is more than 5mol/L, and the leaching rate of vanadium is basically unchanged during leaching. If the concentration of ammonium carbonate solution is increased, the cost of vanadium extraction will be greatly increased. Therefore, the concentration of the ammonium carbonate solution in the present invention is: NH ₄ ⁺ concentration is The concentration of 0.5 to 6 mol/L, HCO ₃ ^- is 0.5 to 6 mol/L, and the concentration of CO ₃ ^2- is 0.5 to 5 mol/L.

As a preferred technical solution, in the method of the present invention, the temperature of the leaching is from normal temperature to 150 ° C, for example, 25 ° C, 35 ° C, 50 ° C, 80 ° C, 95 ° C, 120 ° C, 150 ° C, etc., the temperature is too low. The vanadium leaching efficiency of the clinker-containing raw material after calcination is low, and the leaching rate of vanadium of various roasting clinker at 150 ° C is already high, and it is meaningless to raise the leaching temperature. Therefore, the leaching temperature of the present invention is selected from normal temperature to 150 °C. °C is preferably 50 to 95 ° C, and more preferably 60 to 75 ° C.

As a preferred technical solution, in the method of the present invention, the leaching time is 0.5 h or more, for example, 1 h, 2 h, 3 h, 4 h, etc., and the leaching time is too short, such as less than 0.5 h, and the extraction efficiency of vanadium is low, preferably. For 1 to 3 hours.

According to a preferred embodiment of the present invention, in the leaching process, the mass ratio of the liquid solid product of the ammonium carbonate solution to the clinker-containing raw material after calcination is 2:1 to 10:1 m ³ /t, for example, 4 : 1m ³ /t, 7:1m ³ /t, 9:1m ³ /t, etc., the liquid-solid ratio of the reaction liquid below 2m ³ /t is poor, and the liquid-solid ratio is 10m ³ /t. The amount of vanadium dissolved is sufficient, and it is no longer meaningful to increase the liquid-solid ratio, and is preferably from 3:1 to 6:1 m ³ /t.

As a preferred technical solution, the method of the present invention comprises the steps of: leaching vanadium in a solution of vanadium containing raw materials in a solution of ammonium carbonate, the concentration of the ammonium carbonate solution is: NH ₄ ⁺ concentration of 0.5-6 mol/L, HCO ₃ ^- concentration 0.5 ~ 6mol / L, CO ₃ ^2- concentration 0.5 ~ 5mol / L, leaching temperature is normal temperature ~ 150 ° C, leaching time is more than 0.5h, carbon ammonium solution and vanadium containing raw materials after roasting clinker The liquid-solid ratio is from 2:1 to 10:1 m ³ /t. After leaching, vanadium is introduced into the solution as ammonium vanadate to obtain a leaching residue and a vanadium-containing solution.

Compared with the conventional roasting clinker water immersion/acid leaching process, the vanadium leaching rate is high, and impurities do not enter the vanadium-containing liquid, and the simple and clean separation of vanadium can be realized.

detailed description

To facilitate an understanding of the invention, the invention is set forth below. It should be understood by those skilled in the art that the present invention is not to be construed as limited.

Example 1

The clinker obtained by blank calcination of vanadium slag with a V ₂ O ₅ content of 11.6% at 900 ° C was leached in a solution of NH ₄ ⁺ 6 mol/L, HCO ₃ ^- 6 mol/L ammonium nitrate solution, and the leaching temperature was obtained. At 95 ° C, the solid solution mass ratio of the leachate was 10 m ³ /t, and the leaching time was 3 h, and the leaching residue and the vanadium-containing liquid were obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 94.2%.

Example 2

The V ₂ O ₅ content of 1.5% vanadium titanium magnetite at 850 ℃ obtained after roasting clinker NH ₄ ⁺ concentration ^{_{4mol / L, HCO 3 -,}} CO ₃ ^2- concentration concentration 1mol / L 1mol The vanadium extract was extracted from the ammonium carbonate solution of /L, the leaching temperature was 75 ° C, the solid solution mass ratio of the leachate was 8 m ³ /t, and the leaching time was 2 h, and the leaching residue and the vanadium-containing solution were obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 90.2%.

Example 3

The clinker obtained by calcination of vanadium slag with a V ₂ O ₅ content of 14.7% at 800 ° C is at a concentration of 5 mol/L of NH ₄ ^{+ , a} concentration of 2 mol/L of HCO ₃ ^{and a} concentration of 1 mol/L of CO ₃ ^2- . The vanadium extraction solution was leached with vanadium, the leaching temperature was 150 ° C, the solid matter mass ratio of the leaching solution was 5 m ³ /t, and the leaching time was 2.5 h, and the leaching residue and the ammonia leaching vanadium containing solution were obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 93.4%.

Example 4

The V ₂ O ₅ content of 1.6% at 800 ℃ stone coal fired blank obtained after NH ₄ ⁺ concentration in the clinker 2mol / L, HCO ₃ ^- concentration of lmol / L ammonium bicarbonate solution vanadium leaching, the leaching temperature At 120 ° C, the solid matter mass ratio of the leachate was 6 m ³ /t, and the leaching time was 3 h, and the leaching residue and the ammonia-impregnated vanadium-containing liquid were obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 88.2%.

Example 5

The clinker obtained by calcination of stone coal with a V ₂ O ₅ content of 1.2% at 950 ° C is leached in a solution of NH ₄ ⁺ 6 mol/L, HCO ₃ ^- 6 mol/L ammonium carbonate solution, and the leaching temperature is obtained. At 85 ° C, the leaching solution has a solid ratio of 5 m ³ /t and a leaching time of 2 h, and a leaching slag and an ammonia leaching vanadium containing solution are obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the stone coal was 86.2%.

Example 6

The V ₂ O ₅ content of 7.5% at 700 ℃ vanadium-containing catalyst after calcination blank obtained clinker NH ₄ ⁺ concentration 0.5mol / L, HCO ₃ ^- concentration of 0.5mol / L ammonium bicarbonate solution leaching vanadium The leaching temperature was 60 ° C, the leaching solution solid ratio was 7 m ³ /t, and the leaching time was 4 h, and the leaching slag and the ammonia leaching vanadium containing solution were obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 89.1%.

Example 7

The clinker obtained by blank calcination of vanadium-containing catalyst with V ₂ O ₅ content of 8.3% at 800 ° C is at a concentration of 5 mol/L of NH ₄ ^{+ , a} concentration of 2 mol/L of HCO ₃ ^{and a} concentration of 2 mol/L of CO ₃ ^2- . The vanadium solution is leached to extract vanadium, the leaching temperature is 75 ° C, the leaching liquid solid ratio is 10 m ³ /t, and the leaching time is 2 h, and the leaching slag and the ammonia leaching vanadium containing solution are obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 90.1%.

Example 8

The V ₂ O ₅ content of 1.5% vanadium titanium magnetite at 850 ℃ obtained after calcination clinker blank NH ₄ ⁺ concentration 2mol / L, HCO ₃ ^- concentration of 2mol / L ammonium bicarbonate solution leaching vanadium The leaching temperature is 35 ° C, the leaching liquid solid ratio is 6 m ³ /t, and the leaching time is 1 h, and the leaching slag and the ammonia leaching vanadium containing solution are obtained. The leaching residue was washed, dried, weighed and analyzed for the vanadium content of the residue. The recovery of vanadium in the vanadium slag was 92.1%.

The Applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention by the above embodiments, but the present invention is not limited to the above detailed process equipment and process flow, that is, does not mean that the present invention must rely on the above detailed process equipment and The process can only be implemented. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitution of the various materials of the products of the present invention, addition of auxiliary components, selection of specific means, and the like, are all within the scope of the present invention.

Claims (9)

1. A method for extracting vanadium by clinker carbon ammonium solution after calcination of a vanadium-containing raw material, characterized in that: after calcining the vanadium-containing raw material, the clinker is leached in a solution of ammonium carbonate to extract vanadium, and vanadium is introduced into the solution in the form of ammonium vanadate. Leaching slag and vanadium containing solution.
2. The method according to claim 1, wherein the vanadium-containing material is one or a mixture of two or more of vanadium-titanium magnetite, stone coal, vanadium slag or a vanadium-containing catalyst; wherein the vanadium-containing catalyst is The catalyst before use or the catalyst that cannot be reused after use.
3. The method according to claim 1 or 2, wherein the calcination is one or a combination of two or more of blank calcination and calcification calcination.
4. The method according to any one of claims 1 to 3, wherein the ammonium bicarbonate solution is a NH ₄ HCO ₃ solution, a (NH ₄ ) ₂ CO ₃ solution, NH ₄ HCO ₃ and (NH ₄ ) ₂ CO A mixed solution of _3, a mixed solution of ammonia water and NH ₄ HCO _{3 ,} a mixed solution of ammonia water and (NH ₄ ) ₂ CO _{3 ,} a mixed solution of ammonia water and NH ₄ HCO ₃ and (NH ₄ ) ₂ CO ₃ .
5. The method according to any one of claims 1 to 4, wherein the concentration of the ammonium carbonate solution is based on a molar concentration of each ion in the solution: a concentration of NH ₄ ⁺ of 0.5 to 6 mol/L, and a concentration of HCO ₃ ^- It is 0.5 to 6 mol/L, and the concentration of CO ₃ ^2- is 0.5 to 5 mol/L.
6. The method according to any one of claims 1 to 5, wherein the leaching temperature is from ordinary temperature to 150 ° C, preferably from 50 to 95 ° C, and more preferably from 60 to 75 ° C.
7. The method according to any one of claims 1 to 6, wherein the leaching time is 0.5 h or more, preferably 1 to 3 h.
8. The method according to any one of claims 1 to 7, wherein the mass ratio of the liquid solid product of the ammonium carbonate solution to the clinker-containing raw material after the leaching process is 2:1 to 10:1 m ³ / t is preferably from 3:1 to 6:1 m ³ /t.
9. The method according to claim 1, comprising the steps of: leaching vanadium in the ammonium carbonate solution after calcining the vanadium-containing raw material, wherein the concentration of the ammonium carbonate solution is: NH ₄ ⁺ concentration of 0.5 to 6 mol/L, HCO ₃ ^- concentration of 0.5 ~ 6mol / L, CO ₃ ^2- concentration of 0.5 ~ 5mol / L, leaching temperature is room temperature ~ 150 ℃, leaching time of 0.5h or more, during leaching solution containing ammonium bicarbonate baking cooked vanadium material The liquid-solid ratio of the material is 2:1 to 10:1 m3/t. After leaching, vanadium is introduced into the solution as ammonium vanadate to obtain leaching slag and vanadium-containing liquid.