Method for coupling vanadium extraction through ore pulp electrolysis and new energy utilization

Abstract

The invention provides a method for coupling vanadium extraction through ore pulp electrolysis and new energy utilization. The method comprises the following steps: step 1, crushing a vanadium-containing raw material; step 2, adding a leaching agent into the crushed vanadium-containing raw material, and stirring to obtain ore pulp; 3, the ore pulp is placed in an anode of an electrolytic bath, and an oxidation state substance is added into a cathode of the electrolytic bath; step 4, turning on a power supply, carrying out oxidation reaction on vanadium at the anode of the electrolytic cell, and dissolving the vanadium into the solution by the leaching agent at the same time; and the cathode oxidation-state substance is reduced in the electrolytic bath to obtain a reduction-state substance. According to the green vanadium extraction method, vanadium is leached out through ore pulp electrolysis, electrolytic bath anodic oxidation and a leaching agent. When the oxidation-state substance is water or CO2, the method not only realizes reduction of hydrogen or carbon dioxide, but also replaces an anode oxygen evolution process with an oxidation leaching process of vanadium, so that the cost is remarkably reduced.

Description

Technical Field

[0001] The invention relates to a vanadium extraction technology for vanadium-containing raw materials, and in particular to a method for coupling vanadium extraction by slurry electrolysis with new energy utilization. Background Art

[0002] There are many methods for extracting vanadium from vanadium-containing raw materials, which usually include roasting, leaching, neutralization and vanadium precipitation. Roasting converts insoluble vanadium compounds into soluble compounds, and then dissolves vanadium through water, acid or alkali dissolution. Sodium carbonate or calcium carbonate needs to be added during the roasting process, and a large amount of CO is generated after high-temperature calcination. 2 Emissions and energy consumption.

[0003] The electricity obtained from renewable energy generation can be directly transmitted to the power consumption area through the power grid; in remote areas without power grids, the cost of building power grids is high. The method of water electrolysis can be used to convert electricity into hydrogen, or electrolytic reduction of carbon dioxide to obtain C2 or C3 products, which can then be transported to the required place by truck or pipeline transportation for use as chemical raw materials or fuel. In the conventional method of electrolyzing water to produce hydrogen or electrolytic reduction of carbon dioxide, hydrogen ions and carbon dioxide are reduced in the cathode reaction; at the anode, a four-electron oxidation reaction of oxygen occurs to produce oxygen. The overpotential of the anode reaction is relatively high, which causes the energy consumption of the electrolysis process to remain high. For example, the cost of green methanol is more than 30% higher than that of industrial methanol, and the cost of hydrogen production by electrolysis of water is as high as 5KWh / Nm 3 Due to the high cost of green methanol and green hydrogen, they have no competitive advantage over gray hydrogen and industrial methanol, resulting in stagnation in the commercialization of the hydrogen industry and carbon dioxide electrolysis. Summary of the invention

[0004] The purpose of the present invention is to propose a method for coupling vanadium extraction from ore slurry electrolysis with the utilization of new energy in response to the above problems. The method oxidizes vanadium in the ore slurry at the anode, leaches the vanadium with a leaching agent, and simultaneously performs reactions such as water production of hydrogen or carbon dioxide and carbon monoxide reduction to produce methanol at the cathode. The method couples the electrochemical cathode reaction of hydrogen production and preparation of C2 / C3 with the anode reaction of vanadium oxidation, which not only realizes the utilization of new energy, but also replaces the original costly and useless oxygen evolution process with the oxidation leaching process of vanadium, significantly reducing the cost of vanadium extraction from vanadium-containing raw materials. The present invention couples two high-energy consumption reactions into a single process, significantly reducing the overall cost.

[0005] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for coupling vanadium extraction by slurry electrolysis with new energy utilization, comprising the following steps:

[0007] Step 1, crushing the vanadium-containing raw material;

[0008] Step 2, adding a leaching agent to the vanadium-containing raw material after and / or during pulverization, and stirring to obtain a slurry (anode slurry);

[0009] Step 3: placing the ore pulp in the anode of the electrolytic cell and adding oxidized substances to the cathode of the electrolytic cell;

[0010] Step 4: Turn on the power supply, an oxidation reaction of vanadium occurs at the anode of the electrolytic cell, and the vanadium is dissolved into the solution; at the cathode of the electrolytic cell, the oxidized substance is reduced to obtain the reduced substance.

[0011] Furthermore, the vanadium-containing raw material in step 1 is one or more of vanadium-titanium magnetite, stone coal ore, petroleum ash and vanadium-containing rutile. The vanadium content in the vanadium-containing raw material is 0.5-20%. The valence state of vanadium in the vanadium-containing raw material is not limited.

[0012] Furthermore, after the pulverization in step 1, the particle size of the vanadium-containing raw material is less than 5 um, preferably nano-scale particles.

[0013] Furthermore, the pulverization in step 1 is performed by ball milling.

[0014] Further, the leaching agent in step 2 is one or more of sulfuric acid, hydrochloric acid, ammonia water, sodium hydroxide, potassium hydroxide, sodium chloride, sodium hypochlorite, sodium perchlorate, sodium chlorate, phosphoric acid, sodium phosphate and sodium hydrogen phosphate. The preferred leaching agent is one or more of sulfuric acid, sodium hydroxide and potassium hydroxide.

[0015] Furthermore, the mass ratio of the leaching agent to the vanadium-containing raw material is 1 to 5:1, preferably 1.5 to 3:1.

[0016] Furthermore, the solid content of the slurry in step 2 is 10% to 50%, preferably 20% to 40%.

[0017] Furthermore, the oxidized substance in step 3 is water, vanadium (III) sulfate 2 (SO 4 ) 3 , CO 2 and CO.

[0018] Furthermore, the ratio of the amount of vanadium in the ore slurry in step 3 to the amount of oxidized substance is ≤1:1.

[0019] Furthermore, when the oxidized substance in step 3 is a gas, an electrolyte needs to be added to the cathode of the electrolytic cell. The electrolyte is one or more of sodium hydroxide solution, potassium hydroxide solution, sulfuric acid and phosphoric acid, and the concentration of the electrolyte is 0.5 to 4M.

[0020] Further, in step 4, turn on the power supply and set the current density to 50-500 mA / cm 2 , direct current electrolysis for 1 to 100 hours. The preferred current density is 100 to 300 mA / cm 2 , direct current electrolysis for 2 to 15 hours.

[0021] Furthermore, the reduced substance is hydrogen, vanadium sulfate (VSO 4 ), CO, methane, formic acid, acetic acid.

[0022] Furthermore, the anode reaction may also be other wet reaction processes that require oxidation leaching, such as oxidation leaching reactions of copper, nickel, and iron.

[0023] Another object of the present invention is to disclose a slurry electrolyzer, which can be used for green vanadium extraction. Specifically, the slurry electrolyzer includes an anode, a diaphragm and a cathode, the anode includes a flow channel layer, a diffusion layer and a catalyst, and the cathode includes a flow channel layer, a diffusion layer and a reaction electrode. The slurry electrolyzer is suitable for using CO 2 A method for coupling vanadium extraction from ore slurry electrolysis using gas as an oxidized substance with the utilization of new energy.

[0024] The method of coupling vanadium extraction by slurry electrolysis and utilization of new energy in the present invention has simple, scientific and reasonable steps and has the following advantages compared with the prior art:

[0025] The present invention combines the anodic oxidation process of vanadium with the cathode reduction reaction of the oxidized substance, thereby realizing the oxidation leaching of vanadium in the vanadium-containing raw material while realizing the reduction of the oxidized substance, thus significantly reducing the cost of reducing the oxidized substance and separating vanadium from the vanadium-containing raw material. The process is green, environmentally friendly and low in energy consumption.

[0026] Taking the case where the cathode reduction reaction of the oxidized substance is the electrolytic reduction of carbon dioxide as an example, the reduction of carbon dioxide is achieved, and the originally useless oxidation process of oxygen is replaced by the oxidation and leaching process of vanadium. Similarly, when the cathode reduction reaction of the oxidized substance is the electrolytic reduction process of hydrogen, the reduction of hydrogen is achieved, and the originally useless oxidation process of oxygen is replaced by the oxidation and leaching process of vanadium. DETAILED DESCRIPTION

[0027] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0028] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0029] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0030] In this specification, the numerical range expressed using "above" or "below" means a numerical range including the number.

[0031] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0032] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0033] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0034] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0035] Unless otherwise specified, % in this specification refers to mass percentage.

[0036] Example 1

[0037] This embodiment discloses a method for coupling vanadium extraction by slurry electrolysis with new energy utilization. 2 O 5 The raw material is stone coal ore with a content of 1%, which specifically includes the following steps:

[0038] Step 1: First, grind the stone coal ore to less than 100um, add it into a wet ball mill according to the ratio of stone coal ore to water = 1:1, and ball grind it to 100% less than 5um;

[0039] Step 2: During the ball milling process, sodium hydroxide is continuously added to the slurry, the pH is adjusted to 12 and stirred evenly to obtain an anode slurry with a solid content of 40%. The oxidized substance used in the cathode is CO 2 .

[0040] Step 3: The slurry electrolyzer used in this embodiment includes an anode, a diaphragm and a cathode. The anode includes a flow channel layer, a diffusion layer and a catalyst, and the cathode includes a flow channel layer, a diffusion layer and a reaction electrode. The anode slurry is placed in the anode of the electrolyzer, and an electrolyte 2M sodium hydroxide solution and an oxidized substance CO are added to the cathode of the electrolyzer. 2; The CO 2 The mass ratio of vanadium to stone coal is 1.5:1.

[0041] Anode electrode: nickel foam;

[0042] Cathode electrode: 50-50% bismuth-cerium alloy;

[0043] Diaphragm: Nafion 115;

[0044] Step 4: Turn on the power supply and the current density of electrolysis is 100mA / cm 2 ;

[0045] The cathode carbon dioxide is converted into sodium formate solution, and the specific reaction is as follows:

[0046] CO 2 +H 2 O + 2e = HCOO - +OH -

[0047] The anode slurry is electrolytically oxidized at the anode and reacts with sodium hydroxide to form a sodium vanadate solution;

[0048] After the electrolysis is completed, the anode slurry is filtered to obtain a 0.2 M sodium vanadate solution.

[0049] Example 2

[0050] The embodiment discloses a method for coupling vanadium extraction by slurry electrolysis with utilization of new energy. 2 O 5 The petroleum ash with a content of 14% is used as the raw material, and the specific steps include:

[0051] Step 1: First, grind the petroleum ash to less than 100um, add it into a wet ball mill according to the ratio of petroleum ash to water of 1:3, and continue grinding until 100% is within 5um;

[0052] Step 2: During the ball milling process, sulfuric acid is continuously added to the slurry, the pH value of the solution is maintained at 2.0 and stirred evenly to obtain an anode slurry with a solid content of 30%;

[0053] Step 3, placing the anode slurry in the anode of the electrolytic cell, and adding an oxidized substance 1M sulfuric acid aqueous solution into the cathode of the electrolytic cell;

[0054] The structure of the electrolytic cell is as follows:

[0055] Anode electrode: graphite felt;

[0056] Cathode electrode: platinum / carbon electrode;

[0057] Diaphragm: Nafion 212;

[0058] Step 4: Turn on the power supply. During the electrolysis process, the current density loaded on the electrode is 80 mA / cm 2 ;

[0059] The reaction at the cathode is as follows:

[0060] 2H + +2e=H 2

[0061] The anode slurry is electrolytically oxidized at the anode and reacts with sulfuric acid to obtain a vanadium sulfate solution (VO 2 ) 2 SO 4 ;

[0062] The 2.1M vanadyl sulfate solution is obtained by filtration, and the vanadyl sulfate solution can be sent to subsequent steps for further treatment.

[0063] Example 3

[0064] The embodiment discloses a method for coupling vanadium extraction by slurry electrolysis with utilization of new energy. 2 O 5 The vanadium-titanium magnetite with a content of 0.5% is used as the raw material, and the method specifically comprises the following steps:

[0065] Step 1: First, grind the vanadium-titanium magnetite to less than 100um, add it into a wet ball mill according to the ratio of vanadium-titanium magnetite to water of 1:0.8, and continue grinding until 100% is within 5um;

[0066] Step 2: During the ball milling process, sulfuric acid and phosphoric acid are continuously added to the slurry, the volume ratio of 93% sulfuric acid to 75% phosphoric acid is 10:1, the pH of the solution is maintained at 1.3 and stirred evenly to obtain an anode slurry with a solid content of 20%;

[0067] Step 3: Place the anode slurry in the anode of the electrolytic cell, and add oxidized substances 0.5M sulfuric acid + 1M V to the cathode of the electrolytic cell. 2 (SO 4 ) 3 Aqueous solution of

[0068] The structure of the electrolytic cell is as follows:

[0069] Anode electrode: iridium-plated titanium plate;

[0070] Cathode electrode: carbon felt electrode;

[0071] Diaphragm: Perfluorosulfonic acid resin membrane, 20um thick;

[0072] Step 4: Turn on the power supply and the current density of electrolysis is 50mA / cm 2 ;

[0073] The reaction at the cathode is as follows:

[0074] V 3+ +e=V 2+

[0075] The vanadium-titanium magnetite slurry is oxidized at the anode, wherein vanadium is oxidized to pentavalent and iron is oxidized to trivalent, and reacts with sulfuric acid to obtain a mixed slurry of iron sulfate and slag, which is filtered to obtain a vanadium-containing leaching solution of 0.08M vanadyl sulfate (VO 2 ) 2 SO 4 Solution;

[0076] Continuously passing air into the positive electrode can oxidize the divalent vanadium and restore it to the same trivalent vanadium as the initial state, so that the cathode solution can be reused and recycled during the electrolysis process.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for coupling vanadium extraction by slurry electrolysis with utilization of new energy, characterized in that: The following steps are involved: Step 1, crushing the vanadium-containing raw material; Step 2, adding a leaching agent to the vanadium-containing raw material after and / or during pulverization, and stirring to obtain a slurry; Step 3, placing the slurry in the anode of the electrolytic cell, and adding oxidized substances to the cathode of the electrolytic cell; Step 4: Turn on the power supply, an oxidation reaction of vanadium occurs at the anode of the electrolytic cell, and vanadium is dissolved into the solution; At the cathode of the electrolytic cell, the oxidized substance is reduced to obtain the reduced substance.

2. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: The vanadium-containing raw material in step 1 is one or more of vanadium-titanium magnetite, stone coal, petroleum ash and vanadium-containing rutile; And / or, the vanadium content in the vanadium-containing raw material is 0.5-20%.

3. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: The particle size of the vanadium-containing raw material after crushing in step 1 is less than 5 μm; And / or, the pulverizing in step 1 is performed by ball milling.

4. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: The leaching agent in step 2 is one or more of sulfuric acid, hydrochloric acid, ammonia water, sodium hydroxide, potassium hydroxide, sodium chloride, sodium hypochlorite, sodium perchlorate, sodium chlorate, phosphoric acid, sodium phosphate and sodium hydrogen phosphate.

5. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: The mass ratio of the leaching agent to the vanadium-containing raw material is 1 to 5:

1.

6. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: Step 2: The solid content of the ore slurry is 10% to 50%.

7. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: The oxidized substance in step 3 is one or more of water, vanadium (III) sulfate, CO2 and CO.

8. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: When the oxidized substance in step 3 is a gas, an electrolyte is added to the cathode of the electrolytic cell.

9. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 8, characterized in that: The electrolyte is one or more of sodium hydroxide solution, potassium hydroxide solution, sulfuric acid and phosphoric acid.

10. The method for coupling vanadium extraction by slurry electrolysis with utilization of new energy according to claim 1, characterized in that: Step 4: Turn on the power supply and set the current density to 50-500 mA / cm 2 , DC electrolysis for 1 to 100 hours.