WO2011009352A1

WO2011009352A1 - Method for preparing manganese carbonate

Info

Publication number: WO2011009352A1
Application number: PCT/CN2010/073959
Authority: WO
Inventors: 姜志光; 华东
Original assignee: 贵州红星发展股份有限公司
Priority date: 2009-07-20
Filing date: 2010-06-13
Publication date: 2011-01-27
Also published as: CN101704553B; CN101704553A

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.

Description

Method for preparing manganese sulfate

Technical field

The invention relates to a method for preparing manganese carbonate.

Background technique

There are many methods for synthesizing manganese carbonate. Sodium carbonate is generally used as a synthetic agent. The separation ability of impurities in the synthesis process of this method is weak, especially the separation of calcium and magnesium ions of manganese sulfate is not obvious, and the sodium ions introduced at the same time affect To the quality of manganese carbonate products.

With the development of lithium manganate secondary batteries, correspondingly high-quality narrow-distribution spherical manganese carbonate materials are required. Therefore, the manganese carbonate prepared by the prior method does not satisfy the technical specifications of the secondary battery due to the impurity content, and in particular, the content of the magnesium ion of the bow does not meet the requirements of the secondary battery.

A preparation method for preparing a low-weight manganese sulfate is known from the prior art, and the inventors have proposed a preparation method for preparing high-purity manganese sulfate in the patent application 200910157921.8 for preparing manganese sulfate. First, the reducing sulfides such as SrS, BaS, Sr (HS) ₂ , Ba(HS) ₂ , H ₂ S, S0 ₂ , SO/—, Na ₂ S, NaHS, etc. are quantitatively added to the dioxide by reaction molar ratio. In manganese ore. The purpose of this is to fully react metal ions and sulfides in manganese dioxide ore to form metal sulfides. In order to save raw materials, it is generally necessary to first calculate the content of manganese and iron in the manganese dioxide ore powder, and the molar ratio of the added sulfide to the molar ratio of manganese to iron is 1.1: 1.0 to 2.0: 1.0. Next, the reaction is sufficiently stirred in the range of 40 to 85 ° C, and then the solid phase reactant is separated and washed. In this reaction, the content of manganese oxide or sulfide should be monitored, and the end point of the reaction should be determined. After the reaction reaches the set value, the solid-liquid separation is carried out, and the liquid phase is further processed according to the difference of the added ruthenium, and the solid phase is used. 40 ~ 90 ° C hot water wash, and solid-liquid separation. At this time, the solid phase portion is mainly manganese oxide and metal sulfide. Third, the solid phase product is reacted with 9-12 mol/L of H ₂ S0 ₄ to control the end point of the reaction to be pH 4 ~ 4.5, and the feed amount is controlled according to the MnO content. The concentration of MnS0 _{4 in the} ^^ solution is controlled at 300 ~ 400 g. /L range, solid-liquid separation after completion of the reaction. The solid phase part is mainly a metal sulfide residue, which is washed with hot water of 40 to 90 ° C, and the washing liquid can be returned to the third step as a replenishing liquid. Fourth, the solid-liquid separated solution is acidified with H ₂ SO ₄ to a pH of 2-4 of the solution, and hydrogen peroxide is added and heated to separate the stone-filled material, and the solution is precisely filtered. The filtrate is subjected to evaporation, concentration, crystallization, and dehydration to obtain a manganese sulphate.

Summary of the invention

The invention utilizes the synthesis of manganese sulfate and ammonium hydrogencarbonate to prepare manganese carbonate, and prepares a manganese carbonate material with high purity and a certain particle size distribution. The present invention can be carried out by reacting the manganese sulfate filtrate which has been precisely filtered in the fourth step described above with ammonium hydrogencarbonate to complete the present invention, and it is also possible to use the finally prepared manganese sulfate to react with ammonium hydrogencarbonate. The chemical reactions mainly involved in the present invention are:

MnS0 ₄ +2NH ₄ HC0 ₃ ~► MnC0 ₃ + (NH ₄ ) ₂ S0 ₄ +C0 ₂ †

The invention synthesizes manganese and ammonium bicarbonate, and achieves the purpose of separating calcium and magnesium by utilizing the difference in solubility of hydrogencarbonate. The calcium sulphate solution can be quantitatively synthesized with sodium carbonate solution, but at a certain ionic strength, the solubility of calcium bicarbonate is extremely large, and at this time, the solubility of manganese carbonate is small. The present invention utilizes this to control the acidity of the synthetic liquid, thereby controlling the concentration of carbonate ions in the synthetic liquid to maintain it in a lower concentration range, and retaining most of the calcium ions in the mother liquor while synthesizing manganese carbonate. Thereby achieving separation. The solubility of magnesium in the ammonia solution is extremely high, and the magnesium carbonate can be dissolved in a solution such as ammonium chloride or ammonium sulfate, so that the separation can also be achieved.

The synthesis method of the present invention can obtain manganese carbonate materials having different particle size distributions. The obtained particle size change of manganese carbonate is controlled by two methods of cocurrent synthesis and rehydration synthesis. The rehydration synthesis is to use the first synthesized part as the growth seed crystal, and the latter reaction product is further grown on the surface of the particle, so that different particle distribution can be obtained. Manganese carbonate material.

The process flow chart of the present invention is shown in FIG.

The specific synthesis method is:

First, add manganese sulfate to H ₂ S0 ₄ to adjust the pH to 2-4, preferably 2 - 3 ; Secondly, place the solution in a glass container, control 30 ~ 80 °C, preferably 50 ~ 60 °C In the temperature range, ammonium bicarbonate is added for synthesis under stirring, and the end point of the synthesis is controlled to equimolar reaction to ensure the separation efficiency of the synthetic liquid impurities, solid-liquid separation, and recovery and recovery of the filtrate. Third, the above-mentioned synthetic liquid is solid-liquid separated, and the solid is 1 : 5 The water is washed twice at 80-100 °C, and the washing time is 40-80 minutes. After washing, the manganese carbonate is dried in a vacuum oven at 85 °C for 16 hours to obtain manganese carbonate products.

In the second step above, the control synthesis end point is an equimolar reaction which is determined by chemical method [Mn ²⁺ ] and The concentration of [CO/-] is determined.

The time for the addition of the synthetic agent (ammonium hydrogencarbonate) in the second step above is preferably controlled within 30 - 40 minutes. In order to prepare manganese carbonate of different particle sizes, in the above-mentioned second step forming reaction liquid, manganese sulfate of the acidity of the first step is added in proportion, and then synthesis is carried out by adding ammonium hydrogencarbonate. That is, the first and second steps are repeated in the reaction liquid formed in the second step, so that the manganese carbonate formed in the previous reaction can be used as a seed crystal for the growth of manganese carbonate in the latter synthesis, and manganese carbonate is further grown on the surface of the particles.

DRAWINGS

Figure 1 is a flow chart of the main process of the present invention.

detailed description

H ₂ S0 _{4 was} added to MnS0 ₄ to prepare MnS0 ₄ solutions of different pH values.

Example 1

2000 ml of a 354 g/LMnS0 ₄ solution having a pH of 3 was placed in a 5000 ml beaker, and the electric furnace was heated to a temperature of 35 ± 5 °C. Ammonium bicarbonate was slowly added to 749g of food-grade, process control of the reaction system temperature was maintained at 35 ± 5 ° C range, synthesizing agent added over a period min 40 ° C, after suction filtration synthetic liquid separation, the recovered filtrate (Li ₄ ₂ S0 ₄ , The solid is washed twice with water of 1:5 than 100 ° C, and the washing time is controlled for about 1 hour.

The washed manganese carbonate was placed in a vacuum oven at 85 ° C for 16 hours to obtain a manganese carbonate sample 1 ^# .

Example 2

1000ml of 354g/LMnS0 ₄ solution with pH 2 was placed in a 5000ml beaker, heated in an electric furnace to 55 ± 5 °C, and slowly added with 1.5mol/L NH ₄ HC0 ₃ solution for synthesis. The electric furnace power was adjusted during the synthesis process to maintain the system temperature. The synthesis agent was added at 30 ± 5 ° C for 30 minutes in a volume of 3125 ml.

The above-mentioned synthesized solution was subjected to solid-liquid separation, and the solid portion was heat-washed twice at a ratio of 1:5 to water at 80 ° C for 1 hour, and then suction-filtered and placed in a vacuum oven at 85 ° C for 16 hours to obtain carbonic acid. Manganese sample 2 ^# .

Example 3

500ml of 354g/L MnS0 ₄ solution with a pH of 4 was placed in a 5000ml beaker, and the temperature was raised to 55 ± 5 °C, and 1500ml of 1.50mol/L 丽₄ solution was slowly added, and 354g/l MnS0 _{4 was added.} 500 ml of the solution was added, and 1.511101/1 ₄ } 1 ( _{16 3} solution of 163 ml) was added with stirring, and the time for adding the synthetic agent was maintained for 35 minutes.

The above-mentioned synthesized solution was subjected to solid-liquid separation, and the solid portion was heat-washed twice at a ratio of 1:5 to 100 ° C for 1 hour, and then suction-filtered and placed in a vacuum oven at 85 ° C for 16 hours to obtain carbonic acid. Manganese sample 3 ^#

Example 4

Example 2 was repeated, but the electric furnace power was adjusted during the synthesis to maintain the system temperature at 75 ± 5 ° C, and the obtained manganese carbonate sample 4 ^#

Samples obtained above embodiments MnC0 ₃ content and the impurity content of the data in the following table:

Claims

Claim

A method of preparing manganese carbonate, comprising the steps of:

A added MnS0 ₄ to H ₂ S0 ₄ to adjust the pH to 2-4;

B is synthesized in the temperature range of 30 ~ 80 °C by adding ammonium hydrogencarbonate under stirring, and the synthesis end is controlled to equimolar reaction to obtain a synthetic liquid;

C The above-mentioned synthetic liquid is solid-liquid separated, and the solid phase is washed with hot water of 80 - 100 ° C, and then dried to obtain manganese carbonate.

2. The method of producing manganese carbonate according to claim 1, wherein steps A and 8 are repeated in the synthetic liquid formed in the step B.

The method for producing manganese carbonate according to claim 1 or 2, wherein the pH of the MnS0 ₄ solution in the step A is 2-3.

The method for producing manganese carbonate according to claim 1 or 2, wherein the temperature in the step B is controlled at 50 to 60 °C.

The method for producing manganese carbonate according to claim 1 or 2, wherein the concentration of [Mn ²⁺ ] and [CO/-] is determined by a chemical method in the step B to control the reaction end point.

The method for producing manganese carbonate according to claim 1 or 2, wherein the solid phase obtained in the step C is heat-washed in a ratio of 1:5.

The method for producing manganese carbonate according to claim 1 or 2, wherein the number of washings in the step C is two.

The method of producing manganese carbonate according to claim 7, wherein the time of each washing in the step C is 40 to 80 minutes.