Method for removing lead in vanadium slag calcification vanadium extraction leaching process

Abstract

The invention relates to the technical field of vanadium-lead separation, and discloses a method for removing lead in a vanadium slag calcification vanadium extraction leaching process, which comprises the following steps: collecting data of a blank control group, and determining the dosage of a lead removing agent according to lead concentration data in acid leaching qualified liquid; determining the adding batch and the adding amount of the lead removing agent based on the ratio of the lead concentration in the leaching mother solution to the lead concentration in the acid leaching qualified solution in the blank control group; adding a lead removal agent in batches, and after leaching is finished, carrying out solid-liquid separation to obtain lead precipitate and primary purified liquid; settling and standing the primary purified liquid, and taking the purified qualified liquid at the upper layer as lead and vanadium removed liquid; and the lead-removed vanadium liquid is subjected to vanadium precipitation and drying, and a low-lead APV product is prepared. In the leaching process, sulfides are added in different leaching stages, Pb ions are precipitated while sulfur ions uniformly react with vanadium ions in the solution, and lead removal of the vanadium solution is achieved. According to the method, the lead removal agent is added into the reaction tank in stages in the calcification leaching process, so that new equipment and technological process increase are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of vanadium-lead separation, and in particular to a method for removing lead in a vanadium slag calcification vanadium extraction and leaching process. Background Art

[0002] As an important strategic element, vanadium is widely used in metallurgy, chemical industry, aerospace and other fields. It can significantly improve the strength, toughness and ductility of steel, and provides important support for ensuring the quality of key national projects. my country is rich in vanadium-titanium magnetite resources. Usually, the iron concentrate blast furnace ironmaking-converter vanadium extraction process is used to obtain vanadium slag. The sodium vanadium extraction and calcification vanadium extraction processes are widely used in production. Panzhihua Iron and Steel Group ranks first in the country in vanadium production capacity. Its latest process uses vanadium slag calcification vanadium extraction process to prepare vanadium oxide. The process steps of vanadium slag calcification vanadium extraction mainly include calcium salt roasting, acid leaching, vanadium precipitation, melting / reduction and other processes. Among them, roasting-acid leaching is the key step that affects the entire vanadium oxide yield. The wastewater after vanadium precipitation in Xichang calcification is returned to the leaching and washing process for recycling after being neutralized with limestone to remove manganese and magnesium. Under the subsequent solution circulation, the Pb concentration in the leached vanadium solution gradually increases. At present, the qualified solution of Xichang Vanadium Products Factory contains about 0.012~0.03g / L of Pb, resulting in the Pb content in the precipitated ammonium polyvanadate (APV) reaching about 0.04%, which cannot meet the quality requirements of high-end application fields such as vanadium batteries (Pb <0.01%).

[0003] Both Russia and Panzhihua Iron and Steel have layouts in the field of calcium-based vanadium extraction, but the current national standard "GB 3283-1987 Vanadium Pentoxide Standard" does not have clear requirements for Pb. The APV produced by calcium-based vanadium extraction and provided as vanadium material for vanadium batteries is an original creation of Panzhihua Iron and Steel. There is still a lack of research on Pb removal from qualified liquid containing 0.3 to 0.6 mol / L vanadium at home and abroad.

[0004] Therefore, a method for removing lead during vanadium leaching by calcification of vanadium slag is provided in the prior art. Summary of the invention

[0005] In view of this, the purpose of the embodiment of the present invention is to provide a method for removing lead in the process of vanadium slag calcification vanadium extraction leaching. In the leaching process, the new equipment and process flow are avoided, and the lead removal agent is added in batches in the original leaching stage. The lead removal agent is mixed with V in the solution. 5+ During the reaction, Pb 2+ Precipitation is used to remove lead from the vanadium solution.

[0006] Based on the above purpose, an embodiment of the present invention provides a method for removing lead in a vanadium slag calcification vanadium extraction leaching process, comprising: a. Collect the lead concentration data of the leaching mother liquor and the qualified acid leaching solution during the normal leaching reaction as the blank control group, and determine the dosage of the lead removal agent according to the lead concentration data of the qualified acid leaching solution; b. Determine the batch and amount of lead removal agent added based on the ratio of lead concentration in the leaching mother liquor in the blank control group to the qualified acid leaching solution; c. Based on the result of step b, a lead removal agent is added in batches during the leaching reaction, and solid-liquid separation is performed after the leaching to obtain a lead precipitate and a primary purified liquid; d. Let the first purified liquid settle and take the upper purified qualified liquid as the lead-vanadium removal liquid; e. Precipitate vanadium and dry the deleaded vanadium solution to prepare a low-lead APV product.

[0007] In some embodiments, the vanadium content in the qualified acid leaching solution is 0.3-0.6 mol / L.

[0008] In some embodiments, in step a, the lead removing agent is a sulfide.

[0009] In some embodiments, the sulfide comprises barium sulfide, ammonium sulfide, calcium sulfide, magnesium sulfide.

[0010] In some embodiments, the S in the lead removal agent is, by mole, 2- Molar amount and Pb content in qualified acid leaching solution 2+ The molar ratio is (1:1)~(1:100).

[0011] In some embodiments, the process control parameters of the normal leaching reaction process in step a and the leaching reaction in step c remain the same.

[0012] In some embodiments, in step c, adding the lead remover in batches comprises: After adding the leaching mother liquor, add the lead removal agent once; The secondary lead removal agent is continuously added 10 to 90 minutes after leaching and acid addition, and the addition reaction time of the secondary lead removal agent is adjusted based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified liquor.

[0013] In some embodiments, the amount of lead removal agent added is M1=0.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 )~1.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 ).

[0014] In some embodiments, adjusting the reaction time of adding the secondary lead removal agent based on the ratio of the lead concentration in the leaching mother solution to the lead concentration in the acid leaching qualified solution comprises: C 浸出母液铅浓度 :C 浸出液铅浓度 When the ratio is less than 0.5, the reaction time of adding the secondary lead removal agent: the total leaching reaction time is (1:3) to (2:3); C 浸出母液铅浓度 :C 浸出液铅浓度 When the reaction time of adding the secondary lead removal agent is greater than 0.5, the total leaching reaction time is (1:4) to (3:4).

[0015] In some embodiments, in step d, the standing time is greater than 24 hours.

[0016] The present invention has at least the following beneficial technical effects: The present invention uses soluble sulfide as the raw material of the lead remover and uses sulfide as the lead remover. During the leaching process, sulfide is added at different leaching stages. When the sulfur ions in the lead remover react with the vanadium ions in the solution, the Pb ions are precipitated, thereby removing the lead from the vanadium solution. This method considers adding the lead remover to the reaction tank in stages during the calcification leaching process, thus avoiding the addition of new equipment and process flow. However, the presence of clinker makes the mass transfer process in the impurity removal process more complicated. This patent selects appropriate impurity removal agents and adjusts the addition time. By controlling different times and different lead remover dosages, S 2- With Pb 2+ The probability of binding is reduced, which avoids the rapid release of sulfur ions in a local area to convert H2V 10 O 28 4- Restore to VO 2+ It can evenly react in the solution to effectively remove the lead ions in the solution, and the vanadium liquid after lead removal is used for the subsequent preparation of low-lead APV products that meet the requirements of vanadium batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of an embodiment of a method for removing lead in a vanadium leaching process of calcification of vanadium slag provided by the present invention; Figure 2 The present invention provides a clinker leaching flow chart. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0020] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0021] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] like Figure 1 The present invention provides a method for removing lead in the process of vanadium leaching by calcification of vanadium slag, comprising the following steps: a. Collect the lead concentration data of the leaching mother liquor and the qualified acid leaching solution during the normal leaching reaction as the blank control group, and determine the dosage of the lead removal agent according to the lead concentration data of the qualified acid leaching solution; b. Determine the batch and amount of lead removal agent added based on the ratio of lead concentration in the leaching mother liquor in the blank control group to the qualified acid leaching solution; c. Based on the result of step b, a lead removal agent is added in batches during the leaching reaction, and solid-liquid separation is performed after the leaching to obtain a lead precipitate and a primary purified liquid; d. Let the first purified liquid settle and take the upper purified qualified liquid as the lead-vanadium removal liquid; e. Precipitate vanadium and dry the deleaded vanadium solution to prepare a low-lead APV product.

[0023] The process control parameters of the normal leaching reaction process in step a and the leaching reaction in step c are kept the same, and the wastewater after vanadium extraction and precipitation is returned to the leaching and washing process for recycling after being neutralized by limestone to remove manganese and magnesium. The soluble alkali metal ions in the sulfide system will lead to the enrichment of the soluble alkali metal ions in the system, resulting in the failure of the wastewater circulation in the system.

[0024] Furthermore, in step a, the vanadium content in the qualified acid leaching solution is 0.3-0.6 mol / L. The lead removal agent is a sulfide. Preferably, the sulfide includes barium sulfide, ammonium sulfide, calcium sulfide, and magnesium sulfide.

[0025] Furthermore, based on molar amount, S in the lead remover 2- Molar amount and Pb content in qualified acid leaching solution 2+ The molar ratio is (1:1)~(1:100).

[0026] Further, in step c, adding the lead remover in batches comprises: After adding the leaching mother liquor, add the lead removal agent once; The secondary lead removal agent is continuously added 10 to 90 minutes after leaching and acid addition, and the addition reaction time of the secondary lead removal agent is adjusted based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified liquor.

[0027] Furthermore, the amount of lead remover added at one time is M1=0.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 )~1.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 ).

[0028] Further, adjusting the reaction time of adding the secondary lead removal agent based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified liquor comprises: C 浸出母液铅浓度 :C 浸出液铅浓度 When <0.5, the reaction time of adding secondary lead removal agent: total leaching reaction time is (1:3)~(2:3).

[0029] C 浸出母液铅浓度 :C 浸出液铅浓度 When the reaction time of adding the secondary lead removal agent is greater than 0.5, the total leaching reaction time is (1:4) to (3:4).

[0030] Furthermore, in step c, the leaching reaction is carried out by acid leaching with sulfuric acid, and the leaching temperature is controlled at 10-70°C.

[0031] Furthermore, in step d, the standing time is greater than 24 hours, and after the qualified liquid is discharged, the residue filter filtrate at the bottom of the qualified liquid tank is processed separately.

[0032] Furthermore, in step e, the drying temperature is 90-100° C. and the drying time is 2-3 hours. Further explanation: the vanadium precipitation step in step e is consistent with the vanadium precipitation step of ordinary qualified liquid, but needs to be operated independently in the actual production process to prevent contamination of ordinary qualified liquid without lead removal.

[0033] The clinker leaching process used in the present invention is a conventional process, such as Figure 2 As shown, no further elaboration is required.

[0034] This method can be implemented in the following way in production: First, add 3 to 100 times the amount of Pb 2+ Theoretical S of precipitated lead sulfide 2- , and the stirring is completed when the pump is transporting the liquid to the qualified liquid tank and the qualified liquid is pumped into the qualified liquid tank.

[0035] The reactions involved after adding the lead remover in the first stage are shown in Formulas 1, 2, and 3.

[0036] MS=M 2+ + S 2- (Formula 1) Pb 2+ + S 2- = PbS↓ (Equation 2) 5S 2- + 34H + +H2V 10 O 28 4- =10V 2+ +18H2O+5S↓(Formula 3) The reaction involved in the second stage after adding the lead remover is shown in the formula MS=M 2+ + S 2- (Formula 4) PbO+2H + =Pb 2+ +H2O (Formula 5) PbCO3+2H + =Pb 2+ +H2O +CO2↑ (Formula 6) Pb 2+ + S 2- = PbS↓ (Equation 7) 5S 2- + 34H + + H2V 10 O 28 4- =10V 2+ +18H2O+5S↓(Formula 8) According to the present invention, the lead remover is added to the acidic vanadium solution, and the sulfur ions are slowly released into the solution, and then the reactions in formulas 2, 3, 7, and 8 occur. The rapid release of sulfur ions in a local area and the rapid reaction in formula 1 are avoided, and a small amount of sulfur ions in a local area form precipitation with lead ions, while the remaining majority of sulfur ions react with pentavalent vanadium to convert H2V 10 O 28 4- Restore to VO 2+ This causes lead removal agent failure and vanadium loss. The advantages of the present invention are as follows: (1) the selective precipitation process does not introduce other impurities and will not affect the quality of subsequent vanadium products; (2) the vanadium-lead separation efficiency is high; (3) the operation is simple; and (4) the existing equipment and processes are utilized to the greatest extent.

[0037] The following describes it in detail with reference to specific embodiments.

[0038] Blank control group 100g clinker was weighed and put into 250ml leaching mother liquor in a beaker. The temperature was 50℃ and the stirring was controlled at 300r / min. No lead remover was added. The reaction was continued for 1.5 hours. The mixture was leached with 1:1 industrial sulfuric acid and filtered. The composition of the qualified liquid was shown in Table 1 (Pb 0.024g / L, equivalent to 11.59*10 -5 mol), qualified solution was used to precipitate vanadium, and the APV drying composition was shown in Table 2 (containing Pb 0.03% greater than 0.01%).

[0039] Table 1 Typical components of calcified acid leaching liquor / g·L -1

[0040] Table 2 Typical components of calcified roasted clinker and APV / %

[0041] Example 1 Measure 500ml of mother liquor into a beaker, control stirring at 300r / min, add 0.1g of industrial barium sulfide (industrial barium sulfide contains 50% barium sulfide), add 200g of clinker, and leach with 1:1 industrial sulfuric acid. After leaching for 30 minutes, add 0.2g of industrial barium sulfide to continue the reaction; after reacting for 60 minutes, filter; obtain preliminary qualified liquid, let the qualified liquid stand for 48 hours to obtain qualified liquid, detect Pb in the qualified liquid (0.003g / L, 87.5% lower than that of the comparative qualified liquid), precipitate vanadium to obtain APV drying, and the Pb content in APV is 0.004% (<0.01%).

[0042] Example 2 Measure 500ml of mother liquor into a beaker, control stirring at 300r / min, add 0.2g of industrial barium sulfide (industrial barium sulfide contains 50% barium sulfide), add 200g of clinker, and leach with 1:1 industrial sulfuric acid. After leaching for 30 minutes, add 0.4g of industrial barium sulfide to continue the reaction; after reacting for 60 minutes, filter; obtain preliminary qualified solution, let the qualified solution stand for 48 hours to obtain qualified solution, detect Pb (0.002g / L) in the qualified solution, precipitate vanadium to obtain APV and dry it, the Pb content in APV is 0.003% (<0.01%).

[0043] Example 3 Measure 500ml of mother liquor into a beaker, control stirring at 300r / min, add 0.05g of industrial calcium sulfide, add 200g of clinker, and leaching with 1:1 industrial sulfuric acid. After leaching for 30min, add 0.1g of industrial calcium sulfide to continue the reaction; after reacting for 60min, filter; obtain preliminary qualified solution, let the qualified solution stand for 48 hours to obtain qualified solution, detect Pb (0.004g / L) in the qualified solution, precipitate vanadium to obtain APV drying, and the Pb content in APV is 0.005% (<0.01%).

[0044] Example 4 Measure 500ml of mother liquor into a beaker, control stirring at 300r / min, add 0.1g of industrial ferrous sulfide, add 200g of clinker, and leaching with 1:1 industrial sulfuric acid. After leaching for 30min, add 0.1g of industrial ferrous sulfide to continue the reaction; after reacting for 60min, filter; obtain preliminary qualified liquid, let the qualified liquid stand for 48 hours to obtain qualified liquid, detect Pb (0.003g / L) in the qualified liquid, precipitate vanadium to obtain APV drying, and the Pb content in APV is 0.004% (<0.01%).

[0045] Example 5 Measure 500ml of mother liquor into a beaker, stir at 300r / min, add 2ml of ammonium sulfide (25-30% of the effective ingredient of ammonium sulfide), add 200g of clinker, and leach with 1:1 industrial sulfuric acid. After leaching for 30min, add 4ml of ammonium sulfide to continue the reaction; after reacting for 60min, filter; obtain a preliminary qualified solution, let the qualified solution stand for 48 hours to obtain a qualified solution, detect Pb (0.008g / L) in the qualified solution, precipitate vanadium to obtain APV and dry it, the Pb content in APV is 0.0095% (<0.01%).

[0046] Example 6 17m³ mother liquor was measured and put into the leaching reaction tank, and 5kg industrial barium sulfide (industrial barium sulfide contains 50% barium sulfide) and 5.5 tons of clinker were added, and leached with 1:1 industrial sulfuric acid. After leaching for 30 minutes, 10kg industrial barium sulfide was added to continue the reaction. After reacting for 60 minutes, the reaction was filtered to obtain a preliminary qualified solution. The qualified solution was allowed to stand for 48 hours to obtain a qualified solution. Pb (0.006g / L) in the qualified solution was detected, and APV was dried after precipitating vanadium. The Pb content in APV was 0.0075% (<0.01%).

[0047] The present invention uses soluble sulfide as the raw material of the lead remover. During the calcification leaching process, the lead remover is added to the reaction tank in stages, thus avoiding the addition of new equipment and process flow. 5+The reaction reduces vanadium, but the lead remover of the present invention is used in trace amounts, with small vanadium loss, and the vanadium liquid after lead removal is used for the subsequent preparation of low-lead APV products (lead <0.01%), which has certain technical advantages.

[0048] Although the method for preparing and removing lead from a lead removal agent for calcified acid leaching vanadium solution according to the present invention has been described above in conjunction with exemplary embodiments, it should be clear to those skilled in the art that various modifications may be made to the above embodiments without departing from the spirit and scope of the claims.

[0049] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0050] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0051] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0052] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for removing lead during vanadium slag calcification and vanadium extraction leaching, characterized in that: include: a. Collect the lead concentration data of the leaching mother liquor and the qualified acid leaching solution during the normal leaching reaction as the blank control group, and determine the amount of lead removal agent according to the lead concentration data of the qualified acid leaching solution; b. Determine the batch and amount of lead removal agent added based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified solution in the blank control group; c. Based on the result of step b, a lead removal agent is added in batches during the leaching reaction, and solid-liquid separation is performed after the leaching to obtain a lead precipitate and a primary purified liquid; d. The first purified liquid is allowed to settle and stand, and the upper purified qualified liquid is taken as the lead-vanadium removal liquid; e. Precipitating vanadium and drying the deleaded vanadium solution to prepare a low-lead APV product.

2. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 1, characterized in that: In step a, the vanadium content in the qualified acid leaching solution is 0.3-0.6 mol / L.

3. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 1, characterized in that: In step a, the lead removal agent is a sulfide.

4. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 3, characterized in that: The sulfide includes barium sulfide, ammonium sulfide, calcium sulfide and magnesium sulfide.

5. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 3, characterized in that: In terms of molar amount, the S in the lead remover is 2- The molar amount is the same as the Pb in the acid leaching qualified solution 2+ The molar ratio is (1:1)~(1:100).

6. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 1, characterized in that: The process control parameters of the normal leaching reaction process in step a and the leaching reaction in step c remain the same.

7. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 1, characterized in that: In step c, adding the lead remover in batches comprises: After adding the leaching mother liquor, add the lead remover once; A secondary lead remover is continuously added 10 to 90 minutes after leaching and acid addition, and the reaction time of adding the secondary lead remover is adjusted based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified liquor.

8. The method for removing lead during vanadium leaching from vanadium slag calcification according to claim 7, characterized in that: The amount of lead removal agent added is M1=0.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 )~1.5M 总 (C 浸出母液铅浓度 :C 浸出液铅浓度 ).

9. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 7, characterized in that: Adjusting the reaction time of adding the secondary lead removal agent based on the ratio of the lead concentration in the leaching mother liquor to the lead concentration in the acid leaching qualified liquor comprises: C 浸出母液铅浓度 :C 浸出液铅浓度 When the ratio is less than 0.5, the reaction time of adding the secondary lead removal agent: the total leaching reaction time is (1:3) to (2:3); C 浸出母液铅浓度 :C 浸出液铅浓度 When >0.5, the reaction time of adding the secondary lead removal agent is: the total leaching reaction time (1:4)~(3:4).

10. The method for removing lead in the process of vanadium extraction and leaching from vanadium slag calcification according to claim 1, characterized in that: In step d, the standing time is greater than 24 hours.

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