WO2022205534A1 - Preparation method for electrolytic manganese dioxide for mercury-free alkaline zinc-manganese battery - Google Patents

Abstract

Disclosed in the present invention is a preparation method for electrolytic manganese dioxide for a mercury-free alkaline zinc-manganese battery: first mixing and reacting a portion of electrolytic waste liquid with manganese oxide powder and pyrite powder; then adding industrial sulphuric acid and the remaining electrolytic waste liquid in sequence and, after reacting, adding calcium carbonate or ultrafine manganese oxide powder to remove iron, and press-filtering to obtain a filtrate; adding barium sulphide and manganese fluoride in sequence to remove impurities to obtain a manganese sulphate electrolyte; electrolysing to obtain an EMD semi-finished product; and then crushing, rinsing, press-filtering, and drying to obtain a product. The present method can prepare an EMD product with low impurity content and high product quality.

Description

A kind of preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese battery technical field

The invention belongs to the technical field of electrolytic manganese dioxide production, and in particular relates to a preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese batteries.

Background technique

The production of mercury-free alkaline batteries has high requirements on the impurity content of its raw material electrolytic manganese dioxide (EMD). In the currently commonly used EMD production methods, the high impurity content in the electrolyte is difficult to remove, resulting in EMD products The high content of impurities is not conducive to the production of mercury-free alkaline batteries.

technical solutions

In view of the above deficiencies, the present invention discloses a preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese batteries, which can prepare electrolytic manganese dioxide products with low impurity content and high product quality.

The present invention adopts following technical scheme to realize:

A preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese batteries, comprising the following steps:

(1) Weigh manganese oxide ore powder, pyrite powder, industrial sulfuric acid and electrolytic waste liquid respectively in proportion, and the weight ratio of the manganese oxide ore powder to the pyrite powder is 1: (0.16～0.30), and the oxidation The ratio of the sum of the weight of manganese ore powder and pyrite powder to the sum of the weight of the industrial sulfuric acid and the sulfuric acid in the electrolytic waste liquid is 1: (0.25～0.35), and the ratio of the manganese oxide ore powder and the pyrite powder is The ratio of the weight sum to the weight of the electrolytic waste liquid is 1:(5～7);

Take the electrolytic waste liquid, manganese oxide ore powder and pyrite powder, which accounts for one third of the total electrolytic waste liquid, and mix and react for 0.5h at 90~95℃ and 200~300r/min, and then add it at a uniform speed within 0.5h. Industrial sulfuric acid, continue to react for 0.5h, and then add the remaining electrolytic waste liquid to continue the reaction for 0.5h to obtain a mixed slurry;

(2) At 90～95℃, add calcium carbonate to the mixed slurry to adjust the pH to 4.0～4.5. If the content of divalent iron ions in the mixed slurry is ≥10-5mol/L, add ultrafine manganese oxide ore powder until the divalent iron ion content is ≥10-5mol/L. If the iron ion content is less than 10-5mol/L, continue to add calcium carbonate to the mixed slurry to adjust the pH to 6.0-6.5. If the ferric ion content is greater than or equal to 10-5mol/L, continue to add calcium carbonate until the ferric ion content Less than 10-5mol/L, then the mixed slurry is hydraulically filtered to obtain filtrate A;

(3) Heating the filtrate A to 80-90°C, adding electrolytic waste liquid to adjust the pH to 3.5-4.0, then slowly adding barium sulfide and auxiliary B, stirring and reacting for 1-2 hours, and pressing filtration to obtain filtrate C; the barium sulfide The volume ratio of the weight of the filtrate A to the filtrate A is (20～40) g:1L. The auxiliary agent B is obtained by mixing ethanol and triethanolamine according to the volume ratio of 1:(3～4). The auxiliary agent B and The volume ratio of filtrate A is (1～3):100;

(4) Under the conditions of 80～90℃ and pH of 6.0～6.5, slowly add manganese fluoride and auxiliary D to the filtrate C, stir and react for 2～3h, and filter to obtain purified manganese sulfate solution; The ratio of the weight of manganese to the volume of filtrate C is (40-60) g:1L, and the auxiliary agent D is obtained by adding chitosan to sodium sulfate solution and mixing reaction. The volume ratio of the sodium solution is 1g:100mL, and the volume ratio of the weight of the auxiliary agent D to the filtrate C is (10-20) g:1000L;

(5) The manganese sulfate solution is sent into the electrolytic cell for electrolysis. The temperature of the electrolyte is 98 to 100°C, the anode current density is 55 to 80A/m2, the concentration of sulfuric acid in the electrolyte is 0.35 to 0.70mol/L, and the concentration of manganese sulfate is 0.30-0.50 mol/L, the cell voltage is 2.0-4.0V, the electrolysis period is 10-12 days, and the semi-finished electrolytic manganese dioxide and electrolytic waste liquid are obtained after electrolysis;

(6) The semi-finished electrolytic manganese dioxide is crushed into particles with a particle size of 10mm to 30mm, and then rinsed with hot water at a rinsing temperature of 90 to 95°C until the content of sulfuric acid in the rinse solution is lower than 1g/L, and then ammonia water is used to rinse it. Rinse at 60～70℃, adjust pH to 6.5～7.0, then rinse with hot water at 90～95℃ for 8～10h, then grind the particles to obtain electrolytic manganese dioxide powder with particle size less than 325 mesh;

(7) Add potassium permanganate solution to electrolytic manganese dioxide powder to react for 1 hour, the reaction temperature is 90～95℃, then add ammonia water, continue the reaction for 0.5h, the reaction temperature is 90～95℃, when the pH reaches 6.5～7.0 Then, the electrolytic manganese dioxide powder is obtained by pressure filtration and then dried at 100 ~ 105 ℃, and then blended. The blending time is 16 ~ 24h to obtain the electrolytic manganese dioxide product for mercury-free alkaline zinc-manganese batteries. .

Further, in the manganese oxide ore powder described in step (1), the particle size smaller than 200 mesh accounts for 90%-95% and the mass content of metal manganese is 16-18%, and the particle size smaller than 120 mesh in the pyrite powder accounts for 90%-95%. 90% to 95% and the mass content of the available sulfur participating in the reaction is 30 to 40%, and the industrial sulfuric acid is an industrial sulfuric acid with a mass fraction of 98%.

Further, in the ultrafine manganese oxide ore powder in step (2), the particle size smaller than 325 mesh accounts for 90% to 95%, and the calcium carbonate is nano calcium carbonate.

Further, the stirring speed in step (3) is 200-300 r/min.

Further, the stirring speed in step (4) is 50-100 r/min.

Further, the mass fraction of the sodium sulfate solution is 20-25%, the mass fraction of the ammonia water is 20-25%, and the mass fraction of the potassium permanganate solution is 30-40%.

Further, the weight ratio of the potassium permanganate solution added in the step (7) to the electrolytic manganese dioxide powder is 35:1000.

Further, the weight ratio of ammonia water and electrolytic manganese dioxide powder added in step (7) is 40:1000.

The method firstly uses part of the electrolytic waste liquid to mix and react with manganese oxide ore powder and pyrite powder, so as to dissolve and disperse the manganese oxide ore powder and pyrite powder, and promote the mixed reaction of manganese oxide ore powder and pyrite powder; Add industrial sulfuric acid to supplement acid and control pH for the reaction system, avoid the reaction between industrial sulfuric acid and too much pyrite powder to generate ferric sulfate, inhibit the reaction between pyrite powder and manganese oxide powder, and reduce the utilization rate of raw materials; then The heavy metal impurities in the filtrate are removed by quantitatively adding barium sulfide, and the auxiliary agent prepared by ethanol and triethanolamine is added to promote the dispersion of barium sulfide in the filtrate and prevent barium sulfide from sticking, thereby improving the impurity removal effect of barium sulfide. The use of ammonia water to adjust the pH during the rinsing process can reduce the introduction of impurities sodium and potassium into the EMd product. A small amount of potassium permanganate is added to oxidize and remove the low-valent manganese remaining in the EMD.

Compared with the prior art, the technical solution has the following beneficial effects:

1. The present invention reasonably arranges the feeding sequence of each raw material, promotes the mixing of manganese oxide ore powder and pyrite powder, and improves reaction efficiency. Add calcium carbonate to adjust pH to remove iron impurities; add manganese fluoride to remove calcium, magnesium and other ions, and add a mixed solution of chitosan and sodium sulfate, which can effectively promote manganese fluoride, calcium sulfate, magnesium sulfate and other substances in the solution. The dispersion of manganese fluoride improves the impurity removal effect of manganese fluoride.

2. The process of the invention is simple, the controllability is strong, the utilization rate of raw materials is high, the obtained electrolytic manganese dioxide product has few impurities and high content, and is suitable for producing mercury-free alkaline zinc-manganese batteries.

Description of drawings

Figure 1 is a data table of the test results of the EMD product in Experimental Example 1.

Figure 2 is a data table of the detection results of the EMD product in Experimental Example 2.

FIG. 3 is a data table of test results of EMD products in Experimental Example 3. FIG.

Embodiments of the present invention

The following examples further illustrate the present invention, but are not intended to limit the present invention.

Example 1:

A preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese batteries, comprising the following steps:

(1) Weigh manganese oxide ore powder, pyrite powder, industrial sulfuric acid and electrolytic waste liquid respectively in proportion, the weight ratio of described manganese oxide ore powder and pyrite powder is 1:0.22, and described manganese oxide ore powder and sulfur The ratio of the weight sum of the iron ore powder to the weight sum of the sulfuric acid in the described industrial sulfuric acid and the electrolytic waste liquid is 1:0.30, and the weight sum of the manganese oxide powder and pyrite powder is 1:0.30. The weight ratio of waste liquid is 1:6.5;

Take the electrolytic waste liquid, manganese oxide ore powder and pyrite powder, which accounts for one third of the total electrolytic waste liquid, and mix and react for 0.5h at 90~95℃ and 200~300r/min, and then add it at a uniform speed within 0.5h. Industrial sulfuric acid, continue to react for 0.5h, and then add the remaining electrolytic waste liquid to continue the reaction for 0.5h to obtain a mixed slurry;

The manganese oxide ore powder with a particle size smaller than 200 mesh accounts for 90% to 95% and the mass content of metal manganese is 16 to 18%, and the pyrite powder with a particle size smaller than 120 mesh accounts for 90% to 95% and participates in the reaction. The mass content of the available sulfur is 30 to 40%, and the industrial sulfuric acid is an industrial sulfuric acid with a mass fraction of 98%;

(2) At 90～95℃, add calcium carbonate to the mixed slurry to adjust the pH to 4.0～4.5. If the content of divalent iron ions in the mixed slurry is ≥10-5mol/L, add ultrafine manganese oxide ore powder until the divalent iron ion content is ≥10-5mol/L. If the iron ion content is less than 10-5mol/L, continue to add calcium carbonate to the mixed slurry to adjust the pH to 6.0-6.5. If the ferric ion content is greater than or equal to 10-5mol/L, continue to add calcium carbonate until the ferric ion content Less than 10-5mol/L, then the mixed slurry is hydraulically filtered to obtain filtrate A;

(3) Heating the filtrate A to 85°C, adding electrolytic waste liquid to adjust the pH to 3.8, then slowly adding barium sulfide and auxiliary B, reacting for 1 hour under stirring at 200 r/min, and pressing filtration to obtain filtrate C; the barium sulfide The volume ratio of the weight and the filtrate A is 30g: 1L, the auxiliary agent B is obtained by mixing ethanol and triethanolamine according to the volume ratio of 1:3.0, and the volume ratio of the auxiliary agent B and the filtrate A is 2:100 ;

(4) Under the conditions of 90°C and pH of 6.5, the filtrate C was slowly added with manganese fluoride and auxiliary D, reacted under stirring at 80r/min for 2h, and filtered to obtain a purified manganese sulfate solution; The weight of manganese and the volume ratio of filtrate C are 50g: 1L, and the auxiliary agent D is obtained by adding chitosan to the sodium sulfate solution for mixing and reaction, and the mass ratio of the chitosan to the volume ratio of the sodium sulfate solution It is 1g:100mL, and the volume ratio of the weight of the auxiliary agent D to the filtrate C is 15g:1000L; the mass fraction of the sodium sulfate solution is 20 to 25%;

(5) The manganese sulfate solution is sent into the electrolytic cell for electrolysis. The temperature of the electrolyte is 98 to 100°C, the anode current density is 55 to 80A/m2, the concentration of sulfuric acid in the electrolyte is 0.35 to 0.70mol/L, and the concentration of manganese sulfate is 0.30-0.50 mol/L, the cell voltage is 2.0-4.0V, the electrolysis period is 10-12 days, and the semi-finished electrolytic manganese dioxide and electrolytic waste liquid are obtained after electrolysis;

(6) The semi-finished electrolytic manganese dioxide is crushed into particles with a particle size of 10mm to 30mm, and then rinsed with hot water at a rinsing temperature of 90 to 95°C until the content of sulfuric acid in the rinse solution is lower than 1g/L, and then ammonia water is used to rinse it. Rinse at 60～70℃, adjust pH to 6.5～7.0, then rinse with hot water at 90～95℃ for 8～10h, then grind the particles to obtain electrolytic manganese dioxide powder with particle size less than 325 mesh;

(7) Add potassium permanganate solution to electrolytic manganese dioxide powder to react for 1 hour, the reaction temperature is 90～95℃, then add ammonia water, continue the reaction for 0.5h, the reaction temperature is 90～95℃, when the pH reaches 6.5～7.0 Then, the electrolytic manganese dioxide powder is obtained by pressure filtration and then dried at 100 ~ 105 ℃, and then blended. The blending time is 16 ~ 24h to obtain the electrolytic manganese dioxide product for mercury-free alkaline zinc-manganese batteries. The mass fraction of the ammonia water is 20 to 25%, and the mass fraction of the potassium permanganate solution is 30 to 40%; the weight ratio of the added potassium permanganate solution to the electrolytic manganese dioxide powder is 35:1000; The weight ratio of the added ammonia water to the electrolytic manganese dioxide powder is 40:1000.

Example 2:

The only difference between it and the method described in Example 1 is that the weight ratio of the manganese oxide ore powder to the pyrite powder is 1:0.16, and the sum of the weights of the manganese oxide ore powder and the pyrite powder is the same as the The ratio of the sum of the weight of sulfuric acid in the industrial sulfuric acid and the electrolytic waste liquid is 1:0.35, and the ratio of the weight of the described manganese oxide ore powder and the pyrite powder to the weight of the described electrolytic waste liquid is 1:5; The filtrate A was heated to 90°C, adjusted to pH 4.0, then slowly added barium sulfide and auxiliary B, and reacted for 1.5 under stirring at 250 r/min; the weight ratio of the barium sulfide to the filtrate A was 20g:1L, The auxiliary agent B is obtained by mixing ethanol and triethanolamine according to the volume ratio of 1:3.2, and the volume ratio of the auxiliary agent B to the filtrate A is 1:100; Then, slowly add manganese fluoride and auxiliary agent D, and react for 2.5h under stirring at 50r/min; the volume ratio of the weight of the manganese fluoride to the filtrate C is 40g:1L, and the weight of the auxiliary agent D is 40g:1L. The volume ratio with filtrate C is 10g:1000L.

Example 3:

The only difference between it and the method described in Example 1 is that the weight ratio of the manganese oxide ore powder to the pyrite powder is 1:0.30, and the sum of the weights of the manganese oxide ore powder and the pyrite powder is the same as the The ratio of the weight sum of sulfuric acid in the industrial sulfuric acid and the electrolytic waste liquid is 1:0.25, and the ratio of the weight sum of the described manganese oxide ore powder and the pyrite powder to the weight of the described electrolytic waste liquid is 1:7; The filtrate A was heated to 80°C, the pH was adjusted to 3.5, then barium sulfide and auxiliary B were slowly added, and the reaction was carried out under stirring at 300 r/min for 2 h; the weight ratio of the barium sulfide to the filtrate A was 40 g: 1 L, The auxiliary agent B is obtained by mixing ethanol and triethanolamine according to the volume ratio of 1:4, and the volume ratio of the auxiliary agent B to the filtrate A is 3:100; Then, slowly add manganese fluoride and auxiliary agent D, and react for 3h under stirring at 100r/min; the volume ratio of the weight of the manganese fluoride to the filtrate C is 60g:1L, and the weight of the auxiliary agent D is 60g:1L. The volume ratio of filtrate C was 20g:1000L.

Comparative Example 1:

The only difference between the method and the method described in Example 1 is that in step (1), manganese oxide ore powder, pyrite powder, industrial sulfuric acid and electrolytic waste liquid are directly mixed and reacted.

Comparative Example 2:

The only difference between it and the method described in Example 1 is that, in step (1), the electrolytic waste liquid, which accounts for half of the total amount of electrolytic waste liquid, is first taken to react with manganese oxide ore powder and pyrite powder, and then industrial sulfuric acid and pyrite powder are added in turn. The remaining electrolytic waste solution reacts.

Comparative Example 3:

The only difference between it and the method described in Example 1 is that, in step (3), only barium sulfide is added.

Comparative Example 4:

The only difference between it and the method described in Example 1 is that, in step (4), only manganese fluoride is added.

Comparative Example 5:

The only difference between it and the method described in Example 1 is that, in step (4), the auxiliary agent D is only chitosan.

Experimental example 1:

The EMD samples 1 to 3 were produced according to the methods described in Examples 1 to 3, and the EMD samples 4 to 8 were produced according to the methods described in Comparative Examples 1 to 5. The purity and impurity content of the samples were tested. The specific results are shown in the attached Fig. 1, as can be seen from the data, according to the method of the present invention to produce EMD product fully conforms to the standard described in QB/T 2629-2004 "mercury-free alkaline zinc-manganese dioxide battery electrolytic manganese dioxide".

Experimental example 2:

According to the method described in Example 1, in step (3), the volume ratio of the auxiliary agent B to the filtrate A is 0.5:100, 0.8:100, 1:100, 2:100, 3:100, 4:100, respectively. 100,5:100, detect the purity and impurity content of the gained product, the specific results are shown in accompanying drawing 2, it can be seen from the data that the ratio of auxiliary agent B to filtrate A and barium sulfide needs to be controlled within a certain range to promote the concentration of barium sulfide. For the removal of impurities, if the additive B is too much, the barium sulfide is too dispersed, and the heavy metal sulfide is not easy to aggregate, precipitate and remove, and the removal effect is reduced; if the additive B is too small, the barium sulfide is easy to bond and cannot be effectively diffused, reducing the combination with heavy metal ions. efficiency, can not achieve the effect of impurity removal.

Experimental example 3:

According to the method described in Example 1, in step (4), the weight of the auxiliary agent D and the volume ratio of the filtrate C are respectively 1g:1000L, 5g:1000L, 10g:1000L, 15g:1000L, 20g:1000L, 25g: 1000L, 30g: 1000L, 35g: 1000L, 40g: 1000L, the purity and impurity content of the product were detected, and the specific results are shown in Figure 3.

Claims (2)

A preparation method of electrolytic manganese dioxide for mercury-free alkaline zinc-manganese battery, characterized in that: comprising the following steps: (1) Weigh manganese oxide ore powder, pyrite powder, industrial sulfuric acid and electrolytic waste liquid respectively in proportion, and the weight ratio of the manganese oxide ore powder to the pyrite powder is 1: (0.16～0.30), and the oxidation The ratio of the sum of the weight of manganese ore powder and pyrite powder to the sum of the weight of the industrial sulfuric acid and the sulfuric acid in the electrolytic waste liquid is 1: (0.25～0.35), and the ratio of the manganese oxide ore powder and the pyrite powder is The ratio of the weight sum to the weight of the electrolytic waste liquid is 1:(5～7); Take the electrolytic waste liquid, manganese oxide ore powder and pyrite powder, which accounts for one third of the total electrolytic waste liquid, and mix and react for 0.5h at 90~95℃ and 200~300r/min, and then add it at a uniform speed within 0.5h. Industrial sulfuric acid, continue to react for 0.5h, and then add the remaining electrolytic waste liquid to continue the reaction for 0.5h to obtain a mixed slurry; (2) At 90～95℃, add calcium carbonate to the mixed slurry to adjust the pH to 4.0～4.5. If the content of divalent iron ions in the mixed slurry is ≥10 ^-5 mol/L, add ultra-fine manganese oxide ore powder until the 2 If the ferric ion content is less than 10 ^-5 mol/L, continue to add calcium carbonate to the mixed slurry to adjust the pH to 6.0-6.5. If the ferric ion content is greater than or equal to 10 ^-5 mol/L, continue to add calcium carbonate until the The iron ion content is less than 10 ^-5 mol/L, and then the mixed slurry is hydraulically filtered to obtain filtrate A; (3) Heating the filtrate A to 80-90°C, adding electrolytic waste liquid to adjust the pH to 3.5-4.0, then slowly adding barium sulfide and auxiliary B, stirring and reacting for 1-2 hours, and pressing filtration to obtain filtrate C; the barium sulfide The volume ratio of the weight of the filtrate A to the filtrate A is (20～40) g:1L. The auxiliary agent B is obtained by mixing ethanol and triethanolamine according to the volume ratio of 1:(3～4). The auxiliary agent B and The volume ratio of filtrate A is (1～3):100; (4) Under the conditions of 80～90℃ and pH of 6.0～6.5, slowly add manganese fluoride and auxiliary D to the filtrate C, stir and react for 2～3h, and filter to obtain purified manganese sulfate solution; The ratio of the weight of manganese to the volume of filtrate C is (40-60) g:1L, and the auxiliary agent D is obtained by adding chitosan to sodium sulfate solution and mixing reaction. The volume ratio of the sodium solution is 1g:100mL, and the volume ratio of the weight of the auxiliary agent D to the filtrate C is (10-20) g:1000L; (5) The manganese sulfate solution is sent into the electrolytic cell for electrolysis. The temperature of the electrolyte is 98～100℃, the anode current density is 55～80A/m ² , the concentration of sulfuric acid in the electrolyte is 0.35～0.70mol/L, and the concentration of manganese sulfate is 0.35～0.70mol/L. It is 0.30-0.50 mol/L, the cell voltage is 2.0-4.0V, the electrolysis period is 10-12 days, and the semi-finished electrolytic manganese dioxide and electrolytic waste liquid are obtained after electrolysis; (6) The semi-finished electrolytic manganese dioxide is crushed into particles with a particle size of 10mm to 30mm, and then rinsed with hot water at a rinsing temperature of 90 to 95°C until the content of sulfuric acid in the rinse solution is lower than 1g/L, and then ammonia water is used to rinse it. Rinse at 60～70℃, adjust pH to 6.5～7.0, then rinse with hot water at 90～95℃ for 8～10h, then grind the particles to obtain electrolytic manganese dioxide powder with particle size less than 325 mesh; (7) Add potassium permanganate solution to electrolytic manganese dioxide powder to react for 1 hour, the reaction temperature is 90～95℃, then add ammonia water, continue the reaction for 0.5h, the reaction temperature is 90～95℃, when the pH reaches 6.5～7.0 Then, the electrolytic manganese dioxide powder is obtained by pressure filtration and then dried at 100 ~ 105 ℃, and then blended. The blending time is 16 ~ 24h to obtain the electrolytic manganese dioxide product for mercury-free alkaline zinc-manganese batteries. . The method for preparing electrolytic manganese dioxide for mercury-free alkaline zinc-manganese batteries according to claim 1, wherein the ultrafine manganese oxide ore powder described in step (2) accounts for 90%~ 95%, the calcium carbonate is nano calcium carbonate.