Method For Co-Extraction Of Vanadium, Titanium And Chromium From Vanadium Slag

Abstract

The present disclosure provides a method for co-extraction of vanadium, titanium and chromium from vanadium slag. The method selectively reduces pyroxene and fayalite wrapped on spinel through low-temperature hydrogen reduction, iron removal by ferric chloride, and low-temperature leaching of the vanadium slag by oxalic acid, thereby destroying a structure of the spinel, dissociating a spinel phase and a silicate phase, and fully exposing the spinel phase. The method also directly leaches the vanadium slag at a low temperature by acidity and strong complexation of the oxalic acid, and destroys the structure of the spinel, such that vanadium, titanium, chromium and oxalate are complexed into a solution to co-extract vanadium, titanium and chromium. The present disclosure extracts vanadium, titanium and chromium from the vanadium slag, with a leaching rate each being greater than 99%.

Claims

1. A method for co-extraction of vanadium, titanium and chromium from vanadium slag, comprising the following steps: (1) subjecting vanadium slag to a reduction reaction in a high-temperature reaction furnace to obtain a reduction material; (2) conducting an iron removal reaction on the reduction material with a certain amount of a ferric chloride aqueous solution in a reaction kettle, and filtering, washing and drying after the reaction is completed to obtain an iron-removed product; and (3) conducting a leaching reaction on the iron-removed product with a certain amount of an oxalic acid solution in the reaction kettle, and filtering and washing after the reaction is completed to obtain a leaching solution and leaching residue of vanadium, titanium and chromium.

2. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (1), the vanadium slag is one or two selected from the group consisting of high-grade vanadium slag and low-grade vanadium slag.

3. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (1), the vanadium slag has a particle size of 100 mesh to 500 mesh.

4. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (1), the reduction reaction is conducted at 600° C. to 1,000° C. for 30 min to 150 min.

5. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (1), the reduction reaction is one of hydrogen reduction reaction, carbon reduction reaction, and carbon monoxide reduction reaction.

6. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 5, wherein the hydrogen reduction reaction has a hydrogen flow rate of 50 mL/min to 300 mL/min; the carbon reduction reaction has a carbon addition amount of 8% to 20% of the vanadium slag; and the carbon monoxide reduction reaction has a carbon monoxide flow rate of 70 mL/min to 400 mL/min.

7. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (2), the ferric chloride aqueous solution has a concentration of 200 g/L to 600 g/L, and the ferric chloride aqueous solution and the reduction material have a liquid-to-material ratio of (4-10) mL:1 g; and the iron removal reaction is conducted at 50° C. to 90° C. and 200 r/min to 400 r/min for 30 min to 50 min.

8. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 7, wherein in step (2), the ferric chloride aqueous solution has the concentration of 400 g/L to 500 g/L, and the ferric chloride aqueous solution and the reduction material have the liquid-to-material ratio of (4-10) mL:1 g; and the iron removal reaction is conducted at 60° C. to 70° C. and 350 r/min to 400 r/min for 30 min to 50 min.

9. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 1, wherein in step (3), the oxalic acid solution has a concentration of 5% to 15%, and the oxalic acid solution and the iron-removed product have a liquid-to-material ratio of (4-10) mL:1 g; and the leaching reaction is conducted at 40° C. to 100° C., 0 MPa to 1 MPa and 100 r/min to 500 r/min for 30 min to 120 min.

10. The method for co-extraction of vanadium, titanium and chromium from vanadium slag according to claim 9, wherein in step (3), the oxalic acid solution has the concentration of 5% to 15%, and the oxalic acid solution and the iron-removed product have the liquid-to-material ratio of (6-8) mL:1 g; and the leaching reaction is conducted at 70° C. to 80° C., 0.1 MPa to 1 MPa and 300 r/min to 350 r/min for 30 min to 120 min.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

Example 1

[0024] (1) 5 g of vanadium slag was placed in a high-temperature tubular furnace for hydrogen reduction at 700° C. and a hydrogen flow rate of 100 mL/min for 80 min, and hydrogen-reduced vanadium slag was cooled to room temperature with the furnace.

[0025] (2) 2 g of the hydrogen-reduced vanadium slag and 20 mL of a ferric chloride solution with a concentration of 500 g/L were placed in a reaction kettle for a leaching reaction at 60° C. and 400 r/min for 40 min; and iron-removed vanadium slag was filtered, washed and dried.

[0026] (3) 1.5 g of the iron-removed vanadium slag, 1.48 g of oxalic acid, and 15 mL of deionized water were mixed well into a slurry, and the slurry was added into the reaction kettle for a reaction at 75° C., 0.02 MPa, and 300 r/min for 60 min; a reaction product was cooled to room temperature, filtered and washed to obtain a leaching solution and a leaching residue of vanadium, titanium and chromium.

[0027] The results show that the vanadium slag has a vanadium leaching rate of 98.1%, a titanium leaching rate of 98.4%, and a chromium leaching rate of 97.6%.

Example 2

[0028] (1) 5 g of vanadium slag and 18% of a carbon powder were placed in a high-temperature tubular furnace for reduction at 800° C. for 100 min, and reduced vanadium slag was cooled to room temperature with the furnace.

[0029] (2) 2 g of the reduced vanadium slag and 20 mL of a ferric chloride solution with a concentration of 600 g/L were placed in a reaction kettle for a leaching reaction at 500 r/min for 60 min; and iron-removed vanadium slag was filtered, washed and dried.

[0030] (3) 1 g of the iron-removed vanadium slag, 1.11 g of oxalic acid, and 10 mL of deionized water were mixed well into a slurry, and the slurry was added into the reaction kettle for a reaction at 85° C., 0.03 MPa, and 300 r/min for 60 min; a reaction product was cooled to room temperature, filtered and washed to obtain a leaching solution and a leaching residue of vanadium, titanium and chromium.

[0031] The results show that the vanadium slag has a vanadium leaching rate of 99.5%, a titanium leaching rate of 99.4%, and a chromium leaching rate of 99%.

Example 3

[0032] (1) 5 g of vanadium slag was placed in a high-temperature tubular furnace for reduction at 900° C. and a carbon monoxide flow rate of 100 mL/min for 120 min, and reduced vanadium slag was cooled to room temperature with the furnace.

[0033] (2) 2 g of the reduced vanadium slag and 20 mL of a ferric chloride solution with a concentration of 500 g/L were placed in a reaction kettle for a leaching reaction at 500 r/min for 60 min; and iron-removed vanadium slag was filtered, washed and dried.

[0034] (3) 1 g of the iron-removed vanadium slag, 1.76 g of oxalic acid, and 10 mL of deionized water were mixed well into a slurry, and the slurry was added into the reaction kettle for a reaction at 100° C., 0.1 MPa, and 400 r/min for 60 min; a reaction product was cooled to room temperature, filtered and washed to obtain a leaching solution and a leaching residue of vanadium, titanium and chromium.

[0035] The results show that the vanadium slag has a vanadium leaching rate of 99.8%, a titanium leaching rate of 99.7%, and a chromium leaching rate of 99.5%.

Comparative Example 1

[0036] Vanadium was extracted by traditional sodium salt roasting and calcium roasting. The results show that these methods can only achieve vanadium extraction with a final extraction rate of less than 80%.

Comparative Example 2

[0037] Vanadium, titanium, and chromium were extracted by a method provided in patent CN201911129723.0, including: 1 g of vanadium slag, 1.11 g of oxalic acid, and 10 mL of deionized water were added into a reaction kettle for a reaction at 80° C. for 90 min.

[0038] The results show that the vanadium slag has a vanadium leaching rate of 65.1%, a titanium leaching rate of 64.3%, and a chromium leaching rate of 48.5%.

Comparative Example 3

[0039] A method was the same as that of Comparative Example 2, except that vanadium slag after iron removal by hydrogen reduction was leached with oxalic acid.

[0040] The results show that the vanadium slag has a vanadium leaching rate of 99.4%, a titanium leaching rate of 99.3%, and a chromium leaching rate of 99.1%.

[0041] Specific examples are used herein to explain the principles and embodiments of the present disclosure. The foregoing description of the embodiments is merely intended to help understand the method of the present disclosure and its core ideas; besides, various modifications may be made by a person of ordinary skill in the art to specific embodiments and the scope of application in accordance with the ideas of the present disclosure. In conclusion, the content of the present description shall not be construed as limitations to the present disclosure.