阅读说明：本技术 利用提钒废水制备高纯碳酸锰的方法 (Method for preparing high-purity manganese carbonate by using vanadium extraction wastewater ) 是由 王晓东 张溅波 阳露波 张衡 于 2021-11-04 设计创作，主要内容包括：本发明涉及提钒废水处理回收领域,尤其是一种提钒废水处理并生产高纯碳酸锰的利用提钒废水制备高纯碳酸锰的方法,包括如下步骤：a、向提钒废水中加入pH调节剂,搅拌反应后陈化,随后过滤后取滤液备用；b、向步骤a中得到的滤液中加入除钙剂和晶种,加热搅拌反应后陈化,随后过滤后取滤液备用；c、向步骤b中得到的滤液中加入碱液调节pH,然后加入锰沉淀剂,搅拌反应后陈化,随后过滤后取碳酸锰滤饼烘干,取滤液备用；d、向步骤c得到的滤液中加入固体碱,搅拌反应后过滤得石膏滤饼和合格液。本发明尤其适用于利用提钒废水制备高纯碳酸锰工艺之中。(The invention relates to the field of vanadium extraction wastewater treatment and recovery, in particular to a method for preparing high-purity manganese carbonate by using vanadium extraction wastewater, which comprises the following steps of: a. adding a pH regulator into the vanadium extraction wastewater, stirring for reaction, then aging, and then filtering to obtain a filtrate for later use; b. adding a calcium removing agent and seed crystals into the filtrate obtained in the step a, heating, stirring, reacting, aging, and filtering to obtain a filtrate for later use; c. adding alkali liquor into the filtrate obtained in the step b to adjust the pH value, then adding a manganese precipitator, stirring for reaction, then aging, filtering, drying the manganese carbonate filter cake, and taking the filtrate for later use; d. and c, adding solid alkali into the filtrate obtained in the step c, stirring for reaction, and filtering to obtain a gypsum filter cake and qualified liquid. The method is particularly suitable for the process for preparing high-purity manganese carbonate by using the vanadium extraction wastewater.)

1. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater is characterized by comprising the following steps:

a. adding a pH regulator into the vanadium extraction wastewater, stirring for reaction, then aging, and then filtering to obtain a filtrate for later use;

b. adding a calcium removing agent and seed crystals into the filtrate obtained in the step a, heating, stirring, reacting, aging, and filtering to obtain a filtrate for later use;

c. adding alkali liquor into the filtrate obtained in the step b to adjust the pH value, then adding a manganese precipitator, stirring for reaction, then aging, filtering, drying the manganese carbonate filter cake, and taking the filtrate for later use;

d. and c, adding solid alkali into the filtrate obtained in the step c, stirring for reaction, and filtering to obtain a gypsum filter cake and qualified liquid.

2. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater as claimed in claim 1, wherein: in the step a, the pH regulator is calcium carbonate solid powder, and the particle size of the calcium carbonate solid powder is below 400 meshes.

3. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step a, the pH adjusting end point of the pH adjusting agent is 4.5-5.

4. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step a, the stirring intensity of the heating and stirring is 300-500rpm, the stirring time is 10-30min, and the aging time is 1-3 h.

5. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step b, the calcium removing agent is ammonium oxalate solution with the concentration of 1-5 percent and the addition ratio of n (C)₂O₄ ^2-)：n(Ca²⁺)＝0.8-1:1。

6. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step b, the crystal seeds are calcium oxalate solids, and the addition amount of the crystal seeds is 0.2-1% of the mass of the wastewater.

7. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step b, the heating and stirring temperature is 50-70 ℃, the stirring intensity is 500rpm, the stirring time is 30-60min, and the aging time is 16-24 h.

8. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step c, the alkali liquor is ammonia water, the concentration of the ammonia water is 25%, the pH adjusting end point is 6.5-7.5, the manganese precipitator is a saturated solution of ammonium bicarbonate, and the feeding ratio, namely the molar ratio of ammonium bicarbonate to manganese ions, is 1.5-2: 1.

9. the method for preparing high-purity manganese carbonate by using vanadium extraction wastewater as claimed in claim 8, wherein: in the step c, the stirring intensity is 400-600rpm, the stirring time is 20-30min, the aging time is 2-4h, the drying temperature of the manganese carbonate filter cake is 90-105 ℃, and the drying time is 1-2 h.

10. The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater according to claim 1 or 2, wherein the method comprises the following steps: in the step d, the solid alkali is calcium hydroxide solid, the pH adjusting end point is 9-11, the stirring intensity is 500-800rpm, and the stirring time is 10-30 min.

Technical Field

The invention relates to the field of vanadium extraction wastewater treatment and recovery, in particular to a method for preparing high-purity manganese carbonate by using vanadium extraction wastewater.

Background

The vanadium extraction wastewater is wastewater generated by a vanadium extraction process, has the characteristics of high yield and high manganese and magnesium content, needs to be subjected to impurity removal treatment and then recycled to reduce the process cost and meet the environmental protection requirement, has the manganese content of 10-15g/l and the magnesium content of 4-7g/l, generates a large amount of manganese and magnesium-containing gypsum slag by treating the wastewater by an alkali neutralization method, and wastes 4000-6000 tons of manganese resources each year while the gypsum slag is stacked to have risk. Therefore, how to effectively recover manganese resources in the wastewater becomes a problem which needs to be considered.

Manganese-containing wastewater has complex sources and various types, so various wastewater manganese removal methods are promoted, such as electrolytic method for producing simple substance manganese, oxidation method for producing manganese dioxide, biological method, ion exchange method and the like, but the manganese-containing wastewater has the defects of high raw material requirement and low efficiency. Among various manganese products, manganese carbonate has wide industrial application, can be used as a base fertilizer, a feed additive, a paint raw material and the like, can be used as a high-performance strong magnetic material, is a main raw material for producing soft magnetic ferrite, and is widely applied to the electronic industry, including manufacturing televisions, computers and the like. For example, patent CN201610489434.1 uses industrial waste gas CO2 to treat electrolytic manganese wastewater to produce manganese carbonate, although a certain effect is obtained, the reaction conditions are harsh, the production efficiency is low, and the industrial production prospect is poor. Patent CN201810826826.1 handles manganese-containing waste water that sulfuric acid process titanium dioxide industry produced through the method of adding anion activator and ammonium bicarbonate, has optimized the precipitation process of manganese carbonate, and product quality is better, but the addition of surfactant has increased the treatment cost, greatly influences the nature of waste water simultaneously, is unfavorable for the emission or the retrieval and utilization of waste water, produces secondary waste water easily.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for preparing high-purity manganese carbonate by using vanadium extraction wastewater for treating vanadium extraction wastewater and producing high-purity manganese carbonate.

The technical scheme adopted by the invention for solving the technical problems is as follows: the method for preparing high-purity manganese carbonate by using vanadium extraction wastewater comprises the following steps: a. adding a pH regulator into the vanadium extraction wastewater, stirring for reaction, then aging, and then filtering to obtain a filtrate for later use; b. adding a calcium removing agent and seed crystals into the filtrate obtained in the step a, heating, stirring, reacting, aging, and filtering to obtain a filtrate for later use; c. adding alkali liquor into the filtrate obtained in the step b to adjust the pH value, then adding a manganese precipitator, stirring for reaction, then aging, filtering, drying the manganese carbonate filter cake, and taking the filtrate for later use; d. and c, adding solid alkali into the filtrate obtained in the step c, stirring for reaction, and filtering to obtain a gypsum filter cake and qualified liquid.

Further, in the step a, the pH regulator is calcium carbonate solid powder, and the particle size of the calcium carbonate solid powder is 400 meshes or less.

Further, in the step a, the pH adjusting end point of the pH adjusting agent is 4.5-5.

Further, in the step a, the stirring intensity of the heating and stirring is 300-500rpm, the stirring time is 10-30min, and the aging time is 1-3 h.

Further, in the step b, the calcium removing agent is ammonium oxalate solution with the concentration of 1-5%, and the adding amount ratio is n (C)₂O₄ ^2-)：n(Ca²⁺)＝0.8-1:1。

Further, in the step b, the seed crystal is calcium oxalate solid, and the addition amount of the seed crystal is 0.2-1% of the mass of the wastewater.

Further, in the step b, the heating and stirring temperature is 50-70 ℃, the stirring intensity is 500rpm, the stirring time is 30-60min, and the aging time is 16-24 h.

Further, in the step c, the alkali liquor is ammonia water, the concentration of the ammonia water is 25%, the pH adjusting end point is 6.5-7.5, the manganese precipitator is a saturated solution of ammonium bicarbonate, and the feeding ratio, namely the molar ratio of ammonium bicarbonate to manganese ions, is 1.5-2: 1.

further, in the step c, the stirring intensity is 400-600rpm, the stirring time is 20-30min, the aging time is 2-4h, the drying temperature of the manganese carbonate filter cake is 90-105 ℃, and the drying time is 1-2 h.

Further, in the step d, the solid alkali is calcium hydroxide solid, the pH adjusting endpoint is 9-11, the stirring intensity is 500-800rpm, and the stirring time is 10-30 min.

The invention has the beneficial effects that: the method provided by the invention can be used for removing impurities from the vanadium extraction wastewater and producing high-purity manganese carbonate, thereby realizing the resource treatment of vanadium metallurgy wastewater. The invention relates to a process technology for removing impurities from vanadium extraction wastewater and recycling valuable element manganese, wherein the treated wastewater can be reused in a front-end process, and manganese carbonate can be sold as a product. The method solves the problem of manganese-containing wastewater treatment, avoids the generation of manganese-containing gypsum slag, simultaneously prepares a manganese product with higher economic value, has simple and convenient process and easy realization, and provides conditions for the resource utilization of vanadium metallurgy wastewater. The method is particularly suitable for the process for preparing high-purity manganese carbonate by using the vanadium extraction wastewater.

Drawings

FIG. 1 is a schematic flow diagram of the present invention.

FIG. 2 is an SEM image of high purity manganese carbonate according to the present invention.

Fig. 3 is an XRD pattern of the highly pure manganese carbonate of the present invention.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The method for preparing high-purity manganese carbonate by using vanadium extraction wastewater comprises the following steps: a. adding a pH regulator into the vanadium extraction wastewater, stirring for reaction, then aging, and then filtering to obtain a filtrate for later use; b. adding a calcium removing agent and seed crystals into the filtrate obtained in the step a, heating, stirring, reacting, aging, and filtering to obtain a filtrate for later use; c. adding alkali liquor into the filtrate obtained in the step b to adjust the pH value, then adding a manganese precipitator, stirring for reaction, then aging, filtering, drying the manganese carbonate filter cake, and taking the filtrate for later use; d. and c, adding solid alkali into the filtrate obtained in the step c, stirring for reaction, and filtering to obtain a gypsum filter cake and qualified liquid.

In order to obtain better product quality and realize better control of the corresponding steps, the following steps are preferred: in the step a, the pH regulator is calcium carbonate solid powder, and the particle size of the calcium carbonate solid powder is below 400 meshes. Preferably, in step a, the pH adjusting end point of the pH adjusting agent is 4.5-5. Preferably, in the step a, the stirring intensity of the heating and stirring is 300-500rpm, the stirring time is 10-30min, and the aging time is 1-3 h. Based on the same principle, the following steps are preferred: in the step b, the calcium removing agent is ammonium oxalate solution with the concentration of 1-5 percent and the addition ratio of n (C)₂O₄ ^2-)：n(Ca²⁺) 0.8-1: 1. Preferably, in the step b, the seed crystal is calcium oxalate solid, and the addition amount of the seed crystal is 0.2-1% of the mass of the wastewater. Preferably, in the step b, the heating and stirring temperature is 50-70 ℃, the stirring intensity is 300-500rpm, the stirring time is 30-60min, and the aging time is 16-24 h.

In order to realize accurate control in the step c and improve the product quality, preferably, the alkali solution is ammonia water, the concentration of the ammonia water is 25%, the pH adjusting end point is 6.5-7.5, the manganese precipitator is a saturated solution of ammonium bicarbonate, and the feeding ratio, namely the molar ratio of ammonium bicarbonate to manganese ions, is 1.5-2: 1. preferably, in the step c, the stirring intensity is 400-600rpm, the stirring time is 20-30min, the aging time is 2-4h, the drying temperature of the manganese carbonate filter cake is 90-105 ℃, and the drying time is 1-2 h. Likewise, in the step d, preferably, the solid base is calcium hydroxide solid, the pH regulation endpoint is 9-11, the stirring intensity is 500-800rpm, and the stirring time is 10-30 min.

In the practical operation, in order to avoid that excessive ammonium ions are introduced into the wastewater in the pH adjusting process to influence the recycling of the wastewater, the strong acidity of the wastewater is utilized, the calcium carbonate is utilized for neutralization, and the obtained white gypsum with better gypsum quality can be used for producing related products such as alpha gypsum and the like. The calcium ion in the waste water has a certain content, if not removed, the calcium ion is included in the manganese carbonate product in the manganese precipitation process, the final grade of the product is influenced, so the calcium removal treatment is necessary, and because the calcium content is low, seed crystal is added and the aging time is increased to promote the precipitation reaction. Before the manganese carbonate precipitation reaction, the pH value of the system needs to be strictly regulated and controlled, so that on one hand, the manganese hydroxide precipitation is avoided, and on the other hand, the phenomenon that magnesium is precipitated due to overhigh pH value, and the quality of a manganese carbonate product is influenced is avoided. After the calcium hydroxide is added to adjust the pH value, magnesium-containing gypsum slag is generated, the further utilization of gypsum is not influenced, meanwhile, impurity ions influencing the recycling in the wastewater are treated to reach the standard, the wastewater can be recycled, and the whole treatment process flow is shown in figure 1.

Examples

Example 1

(1) Taking 1L of vanadium extraction wastewater, the components of which are shown in a table 1-1. Adding calcium carbonate powder under stirring at 400rpm, adjusting pH to 5, stopping adding, stirring for 20min, standing for 1 hr, and filtering to obtain gypsum and filtrate.

TABLE 1-1 analysis of the composition (g/l) of vanadium-extracting wastewater

(2) Heating the filtrate to 70 deg.C, adding 7g of calcium oxalate while stirring at 500rpm, and adding 5% ammonium oxalate solution in an amount of n (C)₂O₄ ^2-)：n(Ca²⁺) 0.95: 1, continuously heating and stirring for 50min, aging at room temperature for 24h, and filtering to obtain the calcium-removed filtrate.

(3) Taking the filtrate, stirring and adding ammonia water under the condition of 500rpm, adjusting the pH value to 7.2, stopping adding, adding a saturated ammonium bicarbonate solution, wherein the addition amount is that the molar ratio of ammonium bicarbonate to manganese ions is 2: 1, continuously stirring and reacting for 30min, aging for 3h, and filtering to obtain a manganese-removing filtrate, wherein the components are shown in a table 1-2, and the table shows that the manganese removal rate is over 99 percent, magnesium ions are not greatly lost, and the calcium removal rate is over 90 percent.

TABLE 1-2 composition and content (g/l) of treated wastewater

The manganese carbonate filter cake was dried in an oven at 105 ℃ for 2h and its SEM spectrum is shown in FIG. 2. As can be seen from the figure, most of manganese carbonate product particles are in a regular spherical shape, and a small part of the manganese carbonate product particles are in an irregular square shape, the square particles are mutually stacked together or adsorbed on the surfaces of the spherical particles to form larger aggregates, and the spherical particles are manganese carbonate precipitation products. The diameter of most spherical particles is less than 3 mu m, the size of a small part of agglomerates is more than 10 mu m, and the average particle size range is 1-5 mu m. The XRD pattern is shown in figure 3, and the typical characteristic peaks of manganese carbonate and dolomite appear in the pattern, and according to the analysis of the components of precipitates, a very small amount of calcium ions and magnesium ions form incompatible CaMg (CO)₃)₂(dolomite) is settled, which is the main existing form of impurities in the manganese carbonate product, and the purity is highThe manganese carbonate product composition analysis is shown in tables 1-3. As can be seen from the table, the high-purity manganese carbonate product with the manganese taste of over 45.5 percent is prepared through experiments, and the impurity content of the high-purity manganese carbonate product reaches the GB10503-89 II type qualified product standard.

TABLE 1-3 manganese carbonate product composition and content (%)

(4) And (3) adding calcium hydroxide powder into the residual filtrate under stirring at 600rpm, adjusting the pH to 10, stopping adding, continuously stirring for reaction for 30min, filtering to obtain gypsum slag and qualified water, wherein the composition analysis of the qualified water is shown in tables 1-4, and the table shows that after manganese precipitation treatment, the manganese content of the wastewater is reduced to 0.05g/l, the manganese removal rate is over 99 percent, the magnesium content is still partially remained due to the adjustment of the pH to 10, but the calcium content meets the wastewater reuse requirement, the calcium content is still 0.4g/l due to the addition of the calcium hydroxide, and the other impurity contents all reach the wastewater reuse standard.

TABLE 1-4 composition and content (g/l) of treated wastewater

Example 2

(1) Taking 1L of vanadium extraction wastewater, the components of which are shown in a table 2-1. Adding calcium carbonate powder under stirring at 300rpm, adjusting pH to 4.8, stopping adding, stirring for 30min, standing for 2 hr, and filtering to obtain gypsum and filtrate.

TABLE 2-1 analysis of the composition of vanadium-extracting wastewater (g/l)

(2) Heating the filtrate to 50 deg.C, adding 3g of calcium oxalate while stirring at 400rpm, and adding 4% ammonium oxalate solution in an amount of n (C)₂O₄ ^2-)：n(Ca²⁺) 0.9: 1, continuously heating and stirring for 60min, aging at room temperature for 20h, and filtering to obtain the calcium-removed filtrate.

(3) Taking the filtrate, stirring and adding ammonia water under the condition of 600rpm, adjusting the pH value to 7.5, stopping adding, adding a saturated ammonium bicarbonate solution, wherein the addition amount is that the molar ratio of ammonium bicarbonate to manganese ions is 1.9: 1, continuously stirring and reacting for 30min, aging for 4h, and filtering to obtain manganese-removed filtrate, wherein the components are shown in the table 2-2, and the table shows that the manganese removal rate is more than 94%, the magnesium ions are not greatly lost, and the calcium removal rate is more than 86%.

TABLE 2-2 composition and content (g/l) of treated wastewater

And (3) putting the manganese carbonate filter cake into an oven to be dried for 2h at the temperature of 105 ℃ to obtain the product. The analysis of the high purity manganese carbonate product components is shown in tables 2-3. As can be seen from the table, the high-purity manganese carbonate product with the manganese taste of more than 44.2 percent is prepared through experiments, and the impurity content of the high-purity manganese carbonate product reaches the GB10503-89 II type qualified product standard. The reduction in manganese content of the product compared to example 1 may be due to the reduced calcium removal agent dosage, insufficient aging time, etc.

TABLE 2-3 manganese carbonate product composition and content (%)

(4) And (3) adding calcium hydroxide powder into the residual filtrate under stirring at 800rpm, adjusting the pH to 12, stopping adding, continuously stirring for reaction for 30min, filtering to obtain gypsum slag and qualified water, wherein the composition analysis of the qualified water is shown in tables 2-4, and the table shows that after manganese precipitation treatment, the manganese content of the wastewater is reduced to below 0.01g/l, the manganese removal rate is over 99 percent, the magnesium content is basically removed due to the adjustment of the pH to 12, the requirement of wastewater recycling is met, the calcium content is still 0.4g/l due to the addition of the calcium hydroxide, and the contents of other impurities all reach the wastewater recycling standard.

TABLE 2-4 composition and content (g/l) of the treated wastewater

The method has the advantages of simple and convenient process, easy realization, obvious technical advantages and wide market popularization prospect.