Abstract

Provided is a method for preparing manganese sulfate monohydrate, which comprises the following steps: (1) reacting MnO with (NH4)2SO4 solution under heat, and separating solid from liquid after reaction; (2) determining the concentration of MnSO4 in the resulting solution of step (1), adding equimolar (NH4)2S solution thereto to carry out reaction under agitation, separating solid from liquid after reaction and washing the solid; (3) dissolving the obtained solid with concentrated sulfuric acid, adding hydrogen peroxide to the resulting solution, heating to boiling, adjusting the pH of the solution to 5-6, removing the solid phase through precise filtration, evaporating the filtrate and drying to obtain the MnSO4·H2O product. The impurities are separated away and the amount of byproducts is reduced by this method, and the yield of manganese sulfate is improved.

IPC Classes  ?

• C01G 45/10 - Sulfates

Abstract

Provided is a method for preparing manganese sulfate monohydrate, which comprises the following steps: (1) adding equimolar BaS or SrS solution into manganese sulfate solution to carry out reaction fully, and separating and washing the obtained solid; (2) mixing the solid with deionized water to obtain a slurry, dissolving the slurry with concentrated sulfuric acid, and separating solid from liquid to obtain MnSO4 solution; (3) adding proper amount of hydrogen peroxide to the MnSO4 solution, heating to boiling, adjusting the pH value of the solution to 5-6, evaporating the filtrate after a precise filtration, and crystallizing and drying to obtain MnSO4·H2O product. Manganese sulfate monohydrate can be produced at high yield in a cost-efficient manner by this method.

IPC Classes  ?

• C01G 45/10 - Sulfates

Abstract

Provided is a method for preparing barium titanate, which comprises: dissolving BaCl2∙2H2O into TiCl4 solution to prepare Ba-Ti mixed solution with a Ba/Ti mol ratio of 1:1; adding ammonia and ammonium bicarbonate into deionized water to prepare synthetic agent with a NH4OH/NH4HCO3 mol ratio of 5:1; adding Ba-Ti mixed solution and synthetic agent into a reactor for synthesis to obtain a slurry; press-filtering, thermal washing and then press-filtering, to obtain a filter cake; calcining the filter cake for 1 hour at 590-610 ℃, followed by further calcining for 2 hours at 700-950 ℃; crushing the obtained solid by a crusher, and thereby obtaining barium titanate. The obtained barium titanate is spherical, and has a narrower particle size distribution. The method reduces costs.

IPC Classes  ?

• G01G 23/00 - Auxiliary devices for weighing apparatus

Abstract

Provided is a method for preparing manganese sulfate monohydrate by desulfurizing fume with middle-low grade manganese dioxide ore, which comprises: preparing a slurry by using middle-low grade manganese dioxide ore powder, first infusing sulfur-containing fume in the absorbing device and controlling gas velocity and gas-liquid ratio, and then adding manganese dioxide slurry and controlling the slurry to backwards flow opposite to the sulfur-containing fume, discharging the desulfurized fume from the absorbing device, press-filtering and separating the slurry discharged from the absorbing device, guiding the mother liquor to the absorbing device, and continuing the guide operation until the manganese sulfate in the mother liquor is >= 200 g/l, agitating and washing the obtained filter cake at 60-70 ℃, adjusting pH value of the clear solution obtained by press-filtering and separating to 2-4, adding manganese sulfide under agitation at 25-95 ℃, and filtering and removing impurities, continuing agitating, press-filtering and separating, vaporizing the obtained clear filtrate, and obtaining manganese sulfate monohydrate after drying in the air stream. Desulfurizing efficiency is improved, the production cost of manganese sulfate is reduced, the recycling rate of total manganese is improved, and the valuable metals are recycled in high efficiency.

IPC Classes  ?

• C01G 45/10 - Sulfates
• B01D 53/80 - Semi-solid phase processes, i.e. by using slurries
• B01D 53/50 - Sulfur oxides

Abstract

Provided is a method for circularly purifying manganese sulfate and manganese carbonate, which comprises the following steps: (A) adding ammonium bicarbonate into manganese sulfate solution at 40-80 ℃ as agitating for synthesis, making end point of synthesis as equimolar reaction, separating solids, and washing with hot water to obtain manganese carbonate; (B) adding manganese carbonate into 6-12 mol/L H2SO4 to react, controlling pH value of the reaction solution to 1-2, and heating for boiling; (C) adjusting pH value of the reaction solution of step (B) to 4-5 by adding the manganese carbonate obtained in step (A) into the reaction solution; and (D) carrying out solid-liquid separation of the reaction solution, evaporating and crystallizing the obtained filtrate, and drying to obtain manganese sulfate. High-purity manganese sulfate and manganese carbonate with low calcium and magnesium contents and low potassium and sodium contents can be obtained by this method.

IPC Classes  ?

• C01G 45/10 - Sulfates
• C01G 45/00 - Compounds of manganese

Abstract

Provided is a method for preparing manganese carbonate, which comprises the following steps: adding magnesium sulfate into sulfuric acid, adjusting the pH value to 2 - 4; adding ammonium bicarbonate as agitating at 30 - 80 ℃ for synthesis and making the end point of synthesis to equimolar reaction, to obtain synthetic liquid; performing solid-liquid separation for the synthetic fluid and using hot water of 80 - 100 ℃ to wash the solids and then drying them to obtain manganese carbonate. Manganese carbonate with low calcium and magnesium contents can be prepared by this method, and manganese carbonate with different particle size distribution can be obtained.

IPC Classes  ?

• C01G 45/00 - Compounds of manganese

Abstract

Provided is a method for preparing manganese sulfate (MnSO4), which comprises the following steps: adding reductive sulfide to manganese dioxide ore according to the molar ratio to fully react, determining the end-point of reaction, then separating and washing the solid product; reacting the solid product with 9-12 mol/L H2SO4, keeping the end-point of reaction to pH 3-5 and the MnSO4 concentration in the reaction liquid to 300-400 g/L, and separating solid from liquid after reaction; and using H2SO4 to acidify the separated solution until the pH value of the solution is 2-3, adding hydrogen peroxide and heating, finely filtering to remove the solid part, vaporizing, condensing, crystallizing and dewatering the filtered liquid, and obtaining manganese sulfate. The method enables a plurality of heavy metals to be converted into indissoluble sulfides while obtaining manganous compounds that are dissoluble in acid. At the same time, manganese sulfate low in calcium, magnesium and heavy metals is obtained.

IPC Classes  ?

• C01G 45/10 - Sulfates