CN1161936A

CN1161936A - Method for direct production of manganese sulfate by sulfur dioxide gas

Info

Publication number: CN1161936A
Application number: CN 97102703
Authority: CN
Inventors: 周保强
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-02-18
Filing date: 1997-02-18
Publication date: 1997-10-15
Anticipated expiration: 2017-02-18
Also published as: CN1055067C

Abstract

This method for directly producing manganese sulphate with sulphur dioxide is to pass sulphur dioxide gas into the ore pulp of manganese dioxide for reaction to produce manganese sulphate solution, and then the conventional method is used for treatment to obtain the final product. The active reaction temperature of the manganese dioxide used in this invention shall be lower than 180 deg.C, the manganese content calculated as effective oxygen content and the total manganese amount may have a difference less than 12%, and the leaching-out pH value is 5-6 and 7 at the terminal. This invention uses no sulphuric acid, has no need of reductive roasting, no basic impure metal to be leached out, and the leaching out rate of manganese is high up to 98% over.

Description

Method for directly producing manganese sulfate from sulfur dioxide gas

The invention relates to a method for directly producing industrial manganese sulfate by using sulfur dioxide gas.

Manganese sulfate is an intermediate chemical product, and can be used for preparing various chemical metallurgical products such as manganese carbonate, electrolytic manganese dioxide, electrolytic manganese metal and the like. The existing manganese sulfate production method mainly comprises a reduction roasting-acidolysis method and a two-ore method. The former needs to consume a large amount of reducing fuel, power and sulfuric acid, and has high production cost; the latter consumes a large amount of sulfuric acid and has the problems of strict requirements on the quality of the raw material manganese ore powder, unstable product quality and the like, and particularly, the requirements on the active temperature and the manganese dioxide content of the manganese ore powder cause that the raw material adopting the process has few sources and high price, so that the production cost is overhigh and the industrial production is difficult to bear.

The invention aims to provide a method for producing manganese sulfate by directly reacting sulfur dioxide gas with manganese dioxide without reduction roasting and sulfuric acid, so as to overcome the defects of the prior art.

The method for directly producing industrial manganese sulfate by using sulfur dioxide gas is mainly characterized in that the sulfur dioxide gas is introduced into manganese dioxide ore pulp to react to generate manganese sulfate solution.

And filtering the obtained manganese sulfate solution by using a conventional method, removing impurities, concentrating, crystallizing and drying to obtain a final product.

The activity temperature of the manganese powder is less than 180 ℃.

The difference between the manganese content of the manganese powder converted by the effective oxygen content and the total manganese content is less than 12 percent.

The granularity of the manganese powder is less than 120 meshes.

The leaching is carried out at a pH of 5-6, at the end point at a pH of 6.5-7.5, and at a temperature in the range of 10-95 ℃.

The solid-liquid ratio of agitation leaching is 1: 2-2.5, the agitation intensity is limited by no acid bias in the process, and the interval agitation is adopted, and the leaching time is 7-9 hours.

And sulfur dioxide gas is pressed in from the bottom of the stirring barrel and dispersed into uniform small bubbles through the sieve plate to enter the ore pulp.

The invention is based on the following chemical principles:

a：

the standard electrode potential difference of this reaction was 1.11, so theoretically, the reaction could proceed automatically.

In addition, in the experiment, the following intermediate reaction and side reaction can still occur in the process of directly leaching manganese dioxide ore powder by sulfur dioxide gas:

b：

c：

d：

e：

f：

g：

the physicochemical properties of the manganese powder used and the leaching conditions determine the primary and secondary and direction of the reaction. Particularly, the reaction activity temperature of manganese powder has the greatest influence, and when the temperature is higher than 220 ℃, each reaction hardly occurs; the d, e, f, g reactions also occurred simultaneously at 180 ℃ and 220 ℃ with the pH falling rapidly below 1. The reason is that the manganese dioxide has weak reaction capability, and the filled sulfur dioxide gas cannot be consumed, resulting in the generation of sulfurous acid. However, when the temperature is less than 180 ℃, the reaction speed of manganese dioxide and sulfur dioxide is extremely high, the acidity of the whole reaction process is basically unchanged, the pH value is kept between 5 and 6 at any time, only a, b and c are reacted, and the product is manganese sulfate.

The leaching process is generally carried out in a stirring barrel or a stirring tank, slag washing water and manganese powder are added according to the solid-liquid ratio of 1: 2-2.5, stirring and mixing are started, then sulfur dioxide gas is introduced for reaction, when no black precipitate exists in ore pulp, the pH value is reduced to 4-4.5, the sulfur dioxide gas is required to be closed quickly after the manganese dioxide is completely reacted, lime water is added for stirring, the pH value is adjusted to 7 so as to precipitate arsenic and other impurities, and the leaching process is finished. The obtained leachate can be filtered, concentrated, crystallized and dried by the conventional method.

Compared with the prior art, the invention has the following advantages:

the scheme is stable and reliable, the technical economic index is high, low-grade manganese ore can be adopted, and the utilization rate of manganese ore resources is improved;

the manganese powder is divided into a plurality of grades according to the quality, wherein the first grade and the second grade are used in the battery industry, the third grade and the fourth grade are used for potassium permanganate, manganese sulfate (the existing production method), chemical manganese dioxide, electrolytic manganese metal and electrolytic manganese dioxide, the fifth grade is used for iron removal in the production of electric zinc, the manganese grade in the production of ferromanganese is not lower than 30 percent, and the sixth grade and the seventh grade of manganese powder have no utilization value at present because the grade can not meet the requirements and the alkaline metal content is high.

Because the invention adopts the subacidity condition to leach, the impurities such as calcium, magnesium, silicon, aluminum, iron and the like do not participate in the reaction and do not enter the leachate, so six-grade and seven-grade manganese powder can be used for production, sulfur dioxide is cheap and easily available gas, the cost is very low, compared with the prior art which only can adopt four-grade manganese powder for production, the cost is reduced by 50-60%, and the total yield of manganese can be improved by more than 15 percent and can reach more than 98 percent, thereby greatly improving the utilization rate of manganese ore resources.

2, the acid consumption and the energy consumption are greatly reduced, and the environmental pollution is less;

the invention does not use sulfuric acid and does not need reduction roasting, and sulfur dioxide is obtained by roasting low-value pyrite with spontaneous combustibility, so that a lot of fuel and power can be reduced, the cost can be reduced by more than 40% compared with the cost of the two-ore method only by using a few items, and the roasting of the pyrite is carried out under a closed condition, so the pollution to the environment is small, and protective measures are not needed to be taken for equipment.

3, the production process is shortened, the equipment investment is less, and the implementation is easy.

As the invention does not roast and does not use sulfuric acid for leaching, compared with the prior art, the invention correspondingly shortens the process flow and reduces the operation, thereby reducing the investment of equipment and capital construction and being easy to industrialize when being implemented.

Example 1

The traditional process is originally adopted in a certain chemical plant to produce the manganese sulfate, 3000 tons of manganese sulfate are produced every year, and huge loss occurs due to high production cost. The invention can eliminate reduction roasting process, reduce the cost of fuel, power and wage by 220 yuan/ton, replace four-grade manganese powder with six-grade manganese powder and seven-grade manganese powder with the active temperature less than 180 ℃, the granularity less than 120 meshes and the difference between the manganese content converted by the effective oxygen content and the total manganese content of 2-12%, roast the arsenic-containing pyrite discarded in the separation plant by a fluidized bed furnace to obtain sulfur dioxide gas, and use 10M of sulfur dioxide gas³And a Roots blower is fed to the bottom of the stirring barrel every minute, the Roots blower is divided into small air bubbles with uniform sizes by a stainless steel sieve plate, the small air bubbles are dispersed and enter the ore pulp for reaction, the stirring is carried out once every 1-2 hours, each time the stirring is carried out for 3-5 minutes, when the reaction is carried out for 8 hours, the aeration and the stirring are stopped, no black precipitate exists in the ore pulp, and the reaction is finished. Long-term determination shows that the leaching rate of manganese reaches 85-99%. The leachate is treated according to the original working procedures to obtain the final product. The production according to the scheme reduces the cost of each ton of products by more than 1500 yuan compared with the original cost, and benefits are obtained by 400-.

Example 2

In 1991, a chemical plant invests 1400 ten thousand yuan to build a production line for producing 1500 tons of electrolytic manganese dioxide every year, and a two-ore method is adopted to prepare manganese sulfate electrolyte. Because of low manganese recovery rate, the leaching can be carried out only under high temperature and high acid, a plurality of impurity metals are leached simultaneously, the acid consumption is high, the impurity removal cost is also high, the electrochemical corrosion of equipment is serious, the service life is short, the maintenance cost is high, the production cost is high, and the production is forced to stop production due to loss although the market price of the product is high at that time. By adopting the invention to transform the leaching operation, the production cost can be reduced by 3000-3500 Yuan/ton, and the service life of the equipment can be greatly prolonged. The six-grade manganese powder and the seven-grade manganese powder which have the active temperature of less than 180 ℃ and the difference between the manganese content and the total manganese content of less than 2 percent and are produced according to the sulfur dioxide and the operation conditions of the example 1 are adopted, the manganese leaching rate can reach more than 98.5 percent, the burden of the subsequent impurity removal process is greatly reduced, the total product cost is greatly reduced, and more than 450 ten thousand yuan can be obtained each year according to the market price of the electrolytic manganese dioxide.

Claims

A method for directly producing manganese sulfate from sulfur dioxide gas is characterized in that the sulfur dioxide gas is introduced into manganese dioxide ore pulp to react to generate a manganese sulfate solution.
2, the method for directly producing manganese sulfate from manganese dioxide as claimed in claim 1, characterized in that the manganese sulfate solution obtained is filtered, freed of impurities, concentrated, crystallized and dried by conventional methods to obtain the final product.
The process for direct production of manganese sulfate from manganese dioxide as claimed in claim 1, wherein the manganese powder used has an activation temperature of less than 180 ℃.
The process for producing manganese sulfate directly from manganese dioxide as claimed in claim 1, wherein the difference between the amount of manganese in the manganese powder used in terms of the available oxygen content and the total manganese content is less than 12%.
The process for direct production of manganese sulfate from manganese dioxide as claimed in claim 1, wherein the manganese powder used has a particle size of less than 120 mesh.
Process for the direct production of manganese sulphate from manganese dioxide as claimed in claim 1, characterised in that the leaching is carried out at a pH of 5 to 6, at the end point at a pH of 6.5 to 7.5 and at a temperature in the range 10 to 95 ℃.
The method for directly producing manganese sulfate from manganese dioxide as claimed in claim 1, wherein the solid-to-liquid ratio of agitation leaching is 1: 2-2.5, the agitation intensity is limited to the absence of acid bias in the process, and the agitation is carried out intermittently, and the leaching time is 7-9 hours.
The method for directly producing manganese sulfate from manganese dioxide as claimed in claim 1, wherein the sulfur dioxide gas is pressed in from the bottom of the mixing tank and dispersed into small uniform bubbles through the sieve plate to enter the slurry.