Method for synchronous production of manganese tetraoxide and ferric oxide for soft magnetic material by using marine polymetallic nodules

Abstract

A method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules includes: 1) crushing and grinding marine manganese nodules and baking to a constant weight; thoroughly mixing with a mixed flux and roasting in a muffle furnace; 2) carrying out solid-liquid separation, washing solid-phase precipitates with water, grinding the solid, adding sulfuric acid, controlling the temperature to be below 50° C., and vacuuming a reactor up; 3) adding a reducing agent to react at room temperature for 5-10 min, adding ammonia water to adjust the pH value to 5.5, and carrying out separation and filtering; 4) controlling the temperatures of manganese sulfate and ferric sulfate solutions to be below 50° C., and adding ammonium sulfide; and 5) washing with deionized water, and calcining at 800-900° C. for 1-3 s by a suspension low-temperature instantaneous firing system.

Claims

1. A method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules, comprising the following steps: 1) crushing and grinding marine manganese nodules to less than 5 mm in particle size, baking the crushed and ground marine manganese nodules to a constant weight, thoroughly mixing the baked marine manganese nodules with a mixed flux, and roasting the mixture in a muffle furnace at 800° C. for 30-60 min to a solid-liquid layering, wherein the mixed flux is a two-component molten salt system comprising, by mass, 40% of a flux KBF.sub.4 and 60% of an extractant NaAlF.sub.4; 2) carrying out solid-liquid separation, washing the obtained solid-phase precipitates with water, then grinding the solid to below 5 mm in particle size, putting the ground solid into a reactor with a cooling device, adding sulfuric acid to the reactor, controlling the temperature below 50° C., and evacuating the reactor; 3) adding a reducing agent to the reactor at room temperature for 5-10 min, adding ammonia water to the reactor to adjust the pH value to 5.5, and carrying out separation and filtering to remove impurities to obtain a manganese sulfate and a ferric sulfate reaction solution; 4) controlling the temperatures of the reaction solution to be below 50° C., adding ammonium sulfide in a mass ratio of 1-2% to the reaction solution, and filtering the reaction solution to remove heavy metals and form a purified reaction solution; adding ammonium bicarbonate to the purified reaction solution, and filtering the purified reaction solution to obtain ferric and manganese carbonate precipitates and an ammonium sulfate solution; and 5) evaporating the ammonium sulfate solution to recover ammonium sulfate, washing the ferric and manganese carbonate precipitates with deionized water, and then calcining the washed ferric and manganese carbonate precipitates to form manganese and ferric carbonates at 800-900° C. for 1-3 second(s) with by using a suspension low-temperature instantaneous firing system so that the manganese and ferric carbonates are decomposed into solid manganese tetraoxide and ferric oxide, crushing or sand-milling the solid manganese tetraoxide and ferric oxide, washing the crushed or sand-milled manganese tetraoxide and ferric oxide with deionized water, and drying the washed manganese tetraoxide and ferric oxide to obtain a manganese tetraoxide-ferric oxide composite material, wherein the reducing agent is 1,3,5-triaminobenzene or aminophenol.

2. The method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules according to claim 1, wherein the mass ratio of the pretreated marine manganese nodules to the mixed flux is 1:5.

3. The method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules according to claim 2, wherein the amount of the sulfuric acid solution added is based on the content of manganese dioxide, the amount of sulfuric acid added is 1.5-2 times a theoretical addition of sulfuric acid, and the concentration of the sulfuric acid solution is 400 g/L.

4. The method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules according to claim 3, wherein the aminophenol is any one of o-aminophenol, m-aminophenol and p-aminophenol.

5. The method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules according to claim 4, wherein the amount of the reducing agent added is based on the content of manganese dioxide, and the amount of the reducing agent added is 1.5-2 times a theoretical addition of the reducing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The present invention will be further described below in conjunction with embodiments.

Example 1

(2) Provided was a method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules, including the following steps.

(3) 1) Marine manganese nodules were crushed and ground to less than 5 mm in particle size and then baked to a constant weight in an oven at 110° C. The pretreated marine manganese nodules and a mixed flux were thoroughly mixed in a mass ratio of 1:5 and then roasted in a muffle furnace at 800° C. for 30 min to realize solid-liquid layering, wherein the mixed flux was a two-component molten salt system including, by mass, 40% of a flux KBF.sub.4 and 60% of an extractant NaAlF.sub.4.

(4) 2) Solid-liquid separation was carried out, and the obtained solid-phase precipitates were washed with water and then ground to below 5 mm in particle size and put into a reactor with a cooling device. A 400 g/L sulfuric acid solution was then added to have a reaction. The amount of the sulfuric acid solution added was based on the content of manganese dioxide. The amount of sulfuric acid added was 1.5 times a theoretical addition of sulfuric acid. The temperature was controlled to be below 50° C., and the reactor was evacuated.

(5) 3) A reducing agent 1,3,5-triaminobenzene was then added. The amount of the reducing agent 1,3,5-triaminobenzene added was based on the content of manganese dioxide. The amount of the reducing agent added was 1.5 times a theoretical addition of the reducing agent. After reaction at room temperature for 5-10 min, ammonia water was added to adjust the pH value to 5.5. Separation and filtering were then carried out to remove Ca, Mg, Pb and other impurities to obtain a manganese sulfate solution and a ferric sulfate solution, with an impurity content less than 0.5%.

(6) 4) The temperatures of the manganese sulfate solution and the ferric sulfate solution were controlled to be below 50° C. Ammonium sulfide was then added in a mass ratio of 2%0. The solution was then filtered to further remove heavy metals such as Sn, Ni, Ti and the like out of the manganese sulfate solution. Ammonium bicarbonate was added to the purified manganese sulfate and ferric sulfate solution. The amount of ammonium bicarbonate added was based on the content of manganese dioxide. The amount of ammonium bicarbonate added was twice a theoretical addition of ammonium bicarbonate. The reaction solution was then filtered to obtain ferric and manganese carbonate precipitates and an ammonium sulfate solution.

(7) 5) The ammonium sulfate solution was evaporated to recover ammonium sulfate as an agricultural fertilizer. The manganese and ferric carbonates were washed with deionized water, and then calcined at 800-900° C. for 1-3 second(s) by using a suspension low-temperature instantaneous firing system (as disclosed in ZL 201110100752.1) so that the manganese and ferric carbonates were decomposed into manganese tetraoxide and ferric oxide. The solid manganese tetraoxide and ferric oxide were crushed or sand-milled, washed with deionized water, and then dried to obtain a manganese tetraoxide-ferric oxide composite material used for a soft magnetic material. The impurity content was less than 0.5%. The leaching rates of Mn and Fe were 98.5%.

Example 2

(8) Provided was a method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules, including the following steps.

(9) 1) Marine manganese nodules were crushed and ground to less than 5 mm in particle size and then baked to a constant weight in an oven at 110° C. The pretreated marine manganese nodules and a mixed flux were thoroughly mixed in a mass ratio of 1:5 and then roasted in a muffle furnace at 800° C. for 60 min to realize solid-liquid layering, wherein the mixed flux was a two-component molten salt system including, by mass, 40% of a flux KBF.sub.4 and 60% of an extractant NaAlF.sub.4.

(10) 2) Solid-liquid separation was carried out, and the obtained solid-phase precipitates were washed with water and then ground to below 5 mm in particle size and put into a reactor with a cooling device. A 400 g/L sulfuric acid solution was then added to have a reaction. The amount of the sulfuric acid solution added was based on the content of manganese dioxide. The amount of sulfuric acid added was 2 times a theoretical addition of sulfuric acid. The temperature was controlled to be below 50° C., and the reactor was evacuated.

(11) 3) A reducing agent o-aminophenol was then added. The amount of the reducing agent added was based on the content of manganese dioxide. The amount of the reducing agent added was 1.5 times a theoretical addition of the reducing agent. After reaction at room temperature for 5-10 min, ammonia water was added to adjust the pH value to 5.5. Separation and filtering were then carried out to remove Ca, Mg, Pb and other impurities to obtain a manganese sulfate solution and a ferric sulfate solution, with an impurity content less than 0.5%.

(12) 4) The temperatures of the manganese sulfate solution and the ferric sulfate solution were controlled to be below 50° C. Ammonium sulfide was then added in a mass ratio of 1‰. The solution was then filtered to further remove heavy metals such as Sn, Ni, Ti and the like out of the manganese sulfate solution. Ammonium bicarbonate was added to the purified manganese sulfate and ferric sulfate solution. The amount of ammonium bicarbonate added was based on the content of manganese dioxide. The amount of ammonium bicarbonate added was 1.2 times a theoretical addition of ammonium bicarbonate. The reaction solution was then filtered to obtain ferric and manganese carbonate precipitates and an ammonium sulfate solution.

(13) 5) The ammonium sulfate solution was evaporated to recover ammonium sulfate as an agricultural fertilizer. The manganese and ferric carbonates were washed with deionized water, and then calcined at 800-900° C. for 1-3 s by using a suspension low-temperature instantaneous firing system (as disclosed in ZL 201110100752.1) so that the manganese and ferric carbonates were decomposed into manganese tetraoxide and ferric oxide. The solid manganese tetraoxide and ferric oxide were crushed or sand-milled, washed with deionized water, and then dried to obtain a manganese tetraoxide-ferric oxide composite material used for a soft magnetic material. The impurity content was less than 0.5%. The leaching rates of Mn and Fe were 99.2%.

Example 3

(14) Provided was a method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules, including the following steps.

(15) 1) Marine manganese nodules were crushed and ground to less than 5 mm in particle size and then baked to a constant weight in an oven at 110° C. The pretreated marine manganese nodules and a mixed flux were thoroughly mixed in a mass ratio of 1:5 and then roasted in a muffle furnace at 800° C. for 40 min to realize solid-liquid layering, wherein the mixed flux was a two-component molten salt system including, by mass, 40% of a flux KBF.sub.4 and 60% of an extractant NaAlF.sub.4.

(16) 2) Solid-liquid separation was carried out, and the obtained solid-phase precipitates were washed with water and then ground to below 5 mm in particle size and put into a reactor with a cooling device. A 400 g/L sulfuric acid solution was then added to have a reaction. The amount of the sulfuric acid solution added was based on the content of manganese dioxide. The amount of sulfuric acid added was twice a theoretical addition of sulfuric acid. The temperature was controlled to be below 50° C., and the reactor was evacuated.

(17) 3) A reducing agent m-aminophenol was then added. The amount of the reducing agent added was based on the content of manganese dioxide. The amount of the reducing agent added was 1.5 times a theoretical addition of the reducing agent. After reaction at room temperature for 5-10 min, ammonia water was added to adjust the pH value to 5.5. Separation and filtering were then carried out to remove Ca, Mg, Pb and other impurities to obtain a manganese sulfate solution and a ferric sulfate solution, with an impurity content less than 0.5%.

(18) 4) The temperatures of the manganese sulfate solution and the ferric sulfate solution were controlled to be below 50° C. Ammonium sulfide was then added in a mass ratio of 1‰. The solution was then filtered to further remove heavy metals such as Sn, Ni, Ti and the like out of the manganese sulfate solution. Ammonium bicarbonate was added to the purified manganese sulfate and ferric sulfate solution. The amount of ammonium bicarbonate added was based on the content of manganese dioxide. The amount of ammonium bicarbonate added was 1.5 times a theoretical addition of ammonium bicarbonate. The reaction solution was then filtered to obtain ferric and manganese carbonate precipitates and an ammonium sulfate solution.

(19) 5) The ammonium sulfate solution was evaporated to recover ammonium sulfate as an agricultural fertilizer. The manganese and ferric carbonates were washed with deionized water, and then calcined at 800-900° C. for 1-3 s by using a suspension low-temperature instantaneous firing system (as disclosed in ZL 201110100752.1) so that the manganese and ferric carbonates were decomposed into manganese tetraoxide and ferric oxide. The solid manganese tetraoxide and ferric oxide were crushed or sand-milled, washed with deionized water, and then dried to obtain a manganese tetraoxide-ferric oxide composite material used for a soft magnetic material. The impurity content was less than 0.5%. The leaching rates of Mn and Fe were 98.9%.

Example 4

(20) Provided was a method for synchronous production of manganese tetraoxide and ferric oxide for a soft magnetic material by using marine polymetallic nodules, including the following steps.

(21) 1) Marine manganese nodules were crushed and ground to less than 5 mm in particle size and then baked to a constant weight in an oven at 110° C. The pretreated marine manganese nodules and a mixed flux were thoroughly mixed in a mass ratio of 1:5 and then roasted in a muffle furnace at 800° C. for 40 min to realize solid-liquid layering, wherein the mixed flux was a two-component molten salt system including, by mass, 40% of a flux KBF.sub.4 and 60% of an extractant NaAlF.sub.4.

(22) 2) Solid-liquid separation was carried out, and the obtained solid-phase precipitates were washed with water and then ground to below 5 mm in particle size and put into a reactor with a cooling device. A 400 g/L sulfuric acid solution was then added to have a reaction. The amount of the sulfuric acid solution added was based on the content of manganese dioxide. The amount of sulfuric acid added was 1.5 times a theoretical addition of sulfuric acid. The temperature was controlled to be below 50° C., and the reactor was evacuated.

(23) 3) A reducing agent p-aminophenol was then added. The amount of the reducing agent added was based on the content of manganese dioxide. The amount of the reducing agent added was 1.5 times a theoretical addition of the reducing agent. After reaction at room temperature for 5-10 min, ammonia water was added to adjust the pH value to 5.5. Separation and filtering were then carried out to remove Ca, Mg, Pb and other impurities to obtain a manganese sulfate solution and a ferric sulfate solution, with an impurity content less than 0.5%.

(24) 4) The temperatures of the manganese sulfate solution and the ferric sulfate solution were controlled to be below 50° C. Ammonium sulfide was then added in a mass ratio of 2%0. The solution was then filtered to further remove heavy metals such as Sn, Ni, Ti and the like out of the manganese sulfate solution. Ammonium bicarbonate was added to the purified manganese sulfate and ferric sulfate solution. The amount of ammonium bicarbonate added was based on the content of manganese dioxide. The amount of ammonium bicarbonate added was 1.4 times a theoretical addition of ammonium bicarbonate. The reaction solution was then filtered to obtain ferric and manganese carbonate precipitates and an ammonium sulfate solution.

(25) 5) The ammonium sulfate solution was evaporated to recover ammonium sulfate as an agricultural fertilizer. The manganese and ferric carbonates were washed with deionized water, and then calcined at 800-900° C. for 1-3 s by using a suspension low-temperature instantaneous firing system (as disclosed in ZL 201110100752.1) so that the manganese and ferric carbonates were decomposed into manganese tetraoxide and ferric oxide. The solid manganese tetraoxide and ferric oxide were crushed or sand-milled, washed with deionized water, and then dried to obtain a manganese tetraoxide-ferric oxide composite material used for a soft magnetic material. The impurity content was less than 0.5%. The leaching rates of Mn and Fe were 99%.

(26) While the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that the various modifications, changes, substitutions and variations of the embodiments may be made without departing from the spirit and scope of the invention. The scope of the invention is defined by the appended claims and their equivalents.