CN1276877C

CN1276877C - Method for preparing manganomanganic oxide from native manganese ore

Info

Publication number: CN1276877C
Application number: CN 200410012578
Authority: CN
Inventors: 聂建中; 毋兴
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-09-28
Filing date: 2004-09-28
Publication date: 2006-09-27
Anticipated expiration: 2024-09-28
Also published as: CN1603239A

Abstract

The present invention relates to a method for preparing trimanganese tetroxide from primary manganese ore. A reducing agent is added in the primary manganese ore, then the primary manganese ore is leached by sulphuric acid for preparing the solution of manganese sulphate, and the prepared solution of the manganese sulphate is purified by a purification method comprising chemical trash extraction; the purified solution of the manganese sulphate is atomized and sprayed to a sealed reaction tank, ammonia gas is released into the sealed reaction tank simultaneously, and a hot air flow is blown in the sealed reaction tank for a reaction to obtain precipitated mixture containing manganese; finally, the mixture containing the manganese is pickled, dried and calcined to obtain the trimanganese tetroxide with high purity; the purification of the solution of the manganese sulphate also comprises that the solution of the manganese sulphate goes through a filtering layer composed of manganese dioxide. In the method, by changing the phase state of the reaction, the one-time conversion rate of the manganese is greatly improved, the production cost of the trimanganese tetroxide is reduced, and the cost of per ton of the trimanganese tetroxide produced by the method is 8500 to 9000 yuan; in addition, the purity of the solution of the manganese sulphate is raised by a unique further purification procedure, and furthermore, the quality of the trimanganese tetraoxide is raised.

Description

Method for preparing mangano-manganic oxide from primary manganese ore

Technical Field

The invention relates to a method for preparing manganous-manganic oxide, in particular to a method for preparing manganous-manganic oxide by using primary manganese ore.

Background

The high-purity manganous-manganic oxide is a main raw material for producing high-quality soft magnetic ferrite, the prepared soft magnetic ferrite has a narrow remanence induction curve, can be magnetized repeatedly, has high direct-current resistivity, and can avoid more eddy current loss, so the high-purity manganous-manganic oxide has wide application in the industries of electronics, electrical appliances, electric power and the like. At present, manganous-manganic oxide is used as a raw material for producing the soft magnetic ferrite by replacing manganese carbonate in many domestic magnetic material plants. The high-purity manganous-manganic oxide product has huge requirements and very broad prospects in domestic and international markets.

The existing preparation method of trimanganese tetroxide mainly comprises an electrolytic method and an oxidation-reduction method taking primary manganese ore or manganese sulfate as raw materials.

The electrolytic method is the most conventional and industrialized method for producing the trimanganese tetroxide, and has the advantages that the produced trimanganese tetroxide has higher quality; however, the electrolytic method uses electrolytic manganese as a raw material, the production of the electrolytic manganese needs complex process flow and expensive production equipment, the process is complex, the production cost is high, and the power consumption of one process of aqueous solution electrolysis needs more than 7000 degrees per ton of products. The cost for producing one ton of manganous-manganic oxide by an electrolytic method is between 11000 and 12000 yuan.

Therefore, the primary manganese ore or manganese sulfate is used as a raw material, and the reduction of the production cost is the current trend of research and development in the field of preparation of trimanganese tetroxide. The production of manganous manganic oxide from primary manganese ore is carried out by leaching directly with sulfuric acid to obtain manganese sulfate solution (or preparing manganese sulfate solution from manganese sulfate), namely, primary manganese ore (manganese dioxide as main component) is crushed, adding pyrite, and leaching with sulfuric acid:

the prepared manganese sulfate solution is subjected to a known chemical impurity removal method to remove heavy metal ions such as lead, chromium, arsenic, cobalt, nickel and the like and impurities such as calcium, magnesium, silicon and the like in the solution. The chemical impurity removal is mainly to add various chemical reagents into a manganese sulfate solution to enable heavy metal ions, calcium, magnesium, silicon and the like to form precipitates. The chemical reagents and reaction temperature are different in different methods, but the aim is to remove useless impurities in the manganese sulfate solution. The selection of chemical reagents and reaction temperature should be known in the art. Adding carbonate or alkaline substance (such as ammonia water) into the prepared high-purity manganese sulfate solution to generate manganese carbonate or manganese hydroxide precipitate, and roasting the manganese carbonate or manganese hydroxide to generate manganous-manganic oxide; or directly blowing and oxidizing the manganese sulfate solution in a required acid-base environment to prepare the trimanganese tetroxide.

Patent No. 01106854.X discloses a method for producing manganomanganic oxide, which uses industrial grade MnSO₄-H₂O is taken as raw material to prepare solution, dilute ammonia water with the concentration of less than 10 percent is dripped into the solution after the solution is subjected to impurity removal and purification to generate Mn (OH)₂Precipitating and then roasting to obtain the mangano-manganic oxide. Patent No. 01131543.1 also discloses a method for directly producing high-purity trimanganese tetroxide from manganese salt, which is to directly blow and oxidize manganese sulfate solution (maintaining a certain PH value) after impurity removal and purification to generate trimanganese tetroxide. However, the above methods all react in a liquid phase, and the one-time conversion rate of manganese is low, so that the production cost of trimanganese tetroxide is high, and the industrial use of the method is influenced.

In addition, in the existing method for preparing manganous manganic oxide by using primary manganese ore or manganese sulfate, the chemical impurity removal and purification of the manganese sulfate solution are not thorough, and the final manganous manganic oxide finished product has high impurity content (relative to the manganous manganic oxide produced by an electrolytic method) and low quality, which is also a main factor influencing the large-scale industrial application of the existing method for preparing manganous manganic oxide by using primary manganese ore or manganese sulfate.

Disclosure of Invention

The invention provides a method for preparing manganous-manganic oxide from primary manganese ore, aiming at the problems of low conversion rate of manganese, high cost and relatively poor quality of the existing method for preparing manganous-manganic oxide from primary manganese ore or manganese sulfate.

The invention is realized by adopting the following technical scheme: the method for preparing manganous manganic oxide by using primary manganese ore comprises the steps of adding a reducing agent into the primary manganese ore (manganese dioxide is used as a main component) and leaching the primary manganese ore with sulfuric acid to prepare a manganese sulfate solution, purifying the prepared manganese sulfate solution by a purification method containing chemical impurity removal, spraying the purified manganese sulfate solution into a sealed reaction tank in an atomized mode, releasing ammonia gas into the sealed reaction tank, blowing hot air into the reaction tank, and reacting to obtain a precipitated manganese-containing mixture; and (3) pickling and drying the manganese-containing mixture, and roasting to obtain the trimanganese tetroxide.

The manganese sulfate solution is purified by removing impurities such as lead, chromium, arsenic, cobalt, nickel, calcium, magnesium, silicon and the like in the solution; in a reaction pot, the reaction process is firstly to generate manganese hydroxide Mn (OH)₂Under the action of hot air flow, manganese hydroxide is quickly oxidized to generate manganous-manganic oxide and other manganese oxides, and the reaction principle is different from the prior art (the prior art directly generates manganese hydroxide or manganese carbonate and then carries out roasting, or directly generates manganous-manganic oxide by blowing air into manganese sulfate solution). The manganese-containing mixture thus obtained is predominantly trimanganese tetroxide (about 70%) and contains about 30% of manganese oxide (MnO )₂、Mn₂O₃) And a small amount of manganese hydroxide. Compared with the prior art, the method has the advantages that the phase state of the reaction is changed, namely the reaction form of the prior art under the liquid state that ammonia water is dripped into the manganese sulfate solution or gas is directly blown into the manganese sulfate solution is changed into the reaction form of ammonia gas, atomized manganese sulfate solution and blown hot gas flow under the gaseous state (or fog state), so that the reaction sufficiency is increased, and the conversion rate of the trimanganese tetroxide is improved; at the same time, it is also due to the reaction form of the invention thatSome manganese ions which are not converted into mangano-manganic oxide enter the manganese-containing mixture in the form of other oxides, so that the conversion rate and the utilization rate of manganese are further improved.

The release amount of ammonia matched with the atomized manganese sulfate solution is related to the concentration of ammonia, the release amount is relatively less when the concentration of ammonia is higher, and the release amount is relatively more when the concentration of ammonia is lower; with atomized manganese sulphate solutionThe full reaction is the principle, the ammonia gas release amount is small, and the full reaction (Mn generation) is not realized₃O₄) Excessiveammonia release results in waste. After the ammonia concentration is determined, the release amount of the fully reacted ammonia of the atomized manganese sulfate solution is easily obtained by a person skilled in the chemical field.

The oxidation of manganese should be carried out under heat and therefore the sparged gas stream has a temperature and the selection of the oxidation temperature of manganese is well known to those skilled in the chemical arts.

The purification of the manganese sulfate solution according to the invention also comprises passing the manganese sulfate solution through a filter layer consisting of manganese dioxide. Because the purity of the manganese dioxide is high, new impurities cannot be brought in during filtration; the manganese dioxide is in the form of fine sand, and can remove some impurities, such as H, which are not precipitated in the manganese sulfate solution₂SiO₄Colloidal, small particle Fe (OH)₃And AL (OH)₃And adsorbing trace suspended impurities to further reduce the impurity content of silicon, iron and aluminum, so that the manganese sulfate solution is further purified, and the quality of the final product is improved.

The method greatly improves the utilization rate of manganese and the conversion rate of trimanganese tetroxide (reaching more than 95 percent) by changing the phase state of the reaction, reduces the production cost of trimanganese tetroxide, and has simple process and less investment; the cost of producing one ton of manganomanganic oxide by the method is between 8500 and 9500. And through a unique further purification process, the purity of the manganese sulfate solution is improved, and the quality of the trimanganese tetroxide is further improved. The analysis of the trimanganese tetroxide produced by the method has the following results:

Mn：71.68％	S：0.0006％	Si：0.0034％
Mn：71.68％	S：0.0006％	Si：0.0034％	Ca：0.0012％	Mg：0.0015％		K：0.0029％
Fe：0.0573％	Pb：0.0053％	H₂O：0.38％	Ca：0.0012％	Mg：0.0015％		K：0.0029％
Fe：0.0573％	Pb：0.0053％	H₂O：0.38％	specific surface area: 6.36m²/g		Apparent density: 0.71g/cm³

The technical indexes of the method are basically equal to those of products produced by an electrolytic method, and partial indexes even exceed those of the products produced by the electrolytic method.

Detailed Description

Crushing pyrolusite (one of primary manganese ores) (100-200 meshes), adding pyrite, and leaching by sulfuric acid:

filtering to obtain manganese sulfate solution;

analyzing the heavy metal content of the prepared manganese sulfate solution, adding BaS in an amount which is 2 times of the (theoretical) heavy metal content of the manganese sulfate solution to enable heavy metals such as lead, chromium, arsenic, cobalt, nickel and the like to generate metal sulfide precipitates, and filtering the precipitates; BaSO formed as a result of the reaction₄Good crystallization and coarse particles, plays a role in assisting filtration in the sulfide slag and ensures that the slag is easy to filter. The reaction temperature is 60-90 ℃, and the reaction time is 0.5-1 hour.

Then adding ammonium fluoride into the manganese sulfate solution as a precipitator of calcium and magnesium, wherein the adding amount of the ammonium fluoride is 120 percent of the (theoretical) content of the calcium and the magnesium (obtained by assay analysis), the reaction temperature is 80-100 ℃, and the reaction time is 0.5-1 hour.

And adding ethylammonium sodium thiosulfate into the manganese sulfate solution as a purifying agent to further purify the manganese sulfate solution, wherein trace impurities such as calcium, magnesium and the like are mainly further removed. The addition of the ethylammonium sodium thiosulfate is 120 percent of the theoretical amount of the residual trace impurities, the reaction temperature is 40-60 ℃, and the reaction time is 0.5-1 hour.

Passing the manganese sulfate solution after impurity removal and purification through a filter layer made of manganese dioxide to remove some impurities such as H which are not precipitated in the manganese sulfate solution₂SiO₄Colloidal, small particle Fe (OH)₃And AL (OH)₃And adsorbing the micro suspended impurities to further purify the solution.

Extracting ammonia gas (mass concentration is 20-30%) from liquid ammonia, releasing ammonia gas according to the mass ratio of ammonia gas to manganese sulfate solution (preferably 2: 1) of 1.8-2.8: 1, atomizing manganese sulfate solution and spraying into a sealed reaction tank, and blowing rotary heated airflow at 40-60 deg.C into the reaction tank to obtain superfine manganese-containing mixture.

The resulting manganese-containing mixture is acid-washed (manganese oxide is insoluble in acid), i.e., ion-exchanged pure water98% sulfuric acid in the mass ratio of 1 to 10 to 0.002, washing in a reaction tank to eliminate soluble impurity, drying, roasting at 950-1100 deg.c to decompose Mn (OH)₂]And oxidizing to obtain the high-purity trimanganese tetroxide.

Claims

1. A method for preparing manganous manganic oxide by using primary manganese ore comprises the steps of leaching the primary manganese ore with a reducing agent by sulfuric acid to prepare a manganese sulfate solution, and purifying the prepared manganese sulfate solution by a purification method comprising chemical impurity removal, and is characterized in that: spraying the purified manganese sulfate solution into a sealed reaction tank in an atomized manner, releasing ammonia gas into the sealed reaction tank, blowing hot air flow, and reacting to obtain a precipitated manganese-containing mixture; and (3) pickling and drying the manganese-containing mixture, and roasting to obtain the trimanganese tetroxide.

2. The method for preparing manganomanganic oxide from primary manganese ore as claimed in claim 1, wherein the method comprises the following steps: the purification of the manganese sulphate solution also comprises passing the manganese sulphate solution through a filter layer consisting of manganese dioxide.

3. The method for preparing manganomanganic oxide from primary manganese ore as claimed in claim 1 or 2, wherein the method comprises the following steps: ammonia gas with the mass concentration of 20-30% is selected, the ammonia gas is released and manganese sulfate solution is atomized and sprayed into a sealed reaction tank according to the mass ratio of the ammonia gas to the manganese sulfate solution of 1.8-2.8: 1, and the temperature of blown hot air is 40-60 ℃.

4. The method for preparing manganomanganic oxide from primary manganese ore as claimed in claim 1 or 2, wherein the method comprises the following steps: the manganese-containing mixture is calcined at a high temperature of 950 ℃ and 1100 ℃.

5. The method for preparing manganomanganic oxide from primary manganese ore as claimed in claim 3, wherein the method comprises the following steps: the manganese-containing mixture is calcined at a high temperature of 950 ℃ and 1100 ℃.

6. The method for preparing manganomanganic oxide from primary manganese ore as claimed in claim 1 or 2, wherein the method comprises the following steps: the acid cleaning of the manganese-containing mixture is carried out by putting the manganese-containing mixture, ion exchange pure water and 98 percent sulfuric acid into a reaction tank according to the mass ratio of 1: 10: 0.002.