阅读说明：本技术 一种金属锰粉加压碱浸制备锰酸钾的方法 (Method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder ) 是由 罗文波 罗勋 郑凯 字发国 于 2020-06-29 设计创作，主要内容包括：本发明公开了一种金属锰粉加压碱浸制备锰酸钾的方法,S1、选取金属锰粉、氢氧化钾和水,将选取的金属锰粉、氢氧化钾和水按一定比例加入到加压釜内,在金属锰粉、氢氧化钾和水加入的在金属锰粉、氢氧化钾和水加入的同时通入氧气,本发明涉及锰酸钾制备技术领域。该金属锰粉加压碱浸制备锰酸钾的方法,以金属锰粉为原料,利用氧压碱浸工艺的高温、高压、强氧化气氛等有利条件,锰转换率高达95％以上,得到的产品较卧式釜加压氧化法杂质含量少,很大程度上提高了产品品质以及锰转换效率,采用的氧压碱浸工艺的加压釜自动化程度高,因此操作更简便,能降低劳动强度,实现生产的连续化,很大程度上提高了生产效率。(The invention discloses a method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder, which comprises the steps of S1, selecting metal manganese powder, potassium hydroxide and water, adding the selected metal manganese powder, potassium hydroxide and water into a pressure kettle according to a certain proportion, and introducing oxygen while adding the metal manganese powder, potassium hydroxide and water, wherein the metal manganese powder, potassium hydroxide and water are added. The method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder takes metal manganese powder as a raw material, and utilizes the favorable conditions of high temperature, high pressure, strong oxidizing atmosphere and the like of the oxygen pressure alkaline leaching process, the manganese conversion rate is up to more than 95%, the obtained product has less impurity content compared with a horizontal kettle pressure oxidation method, the product quality and the manganese conversion efficiency are improved to a great extent, and the automatic degree of a pressure kettle of the oxygen pressure alkaline leaching process is high, so the method is simpler and more convenient to operate, can reduce the labor intensity, realizes the production continuity, and improves the production efficiency to a great extent.)

1. A method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder is characterized in that: the method specifically comprises the following steps:

s1, selecting metal manganese powder, potassium hydroxide and water, adding the selected metal manganese powder, potassium hydroxide and water into a pressure kettle according to a certain proportion, introducing oxygen while adding the metal manganese powder, potassium hydroxide and water, pressurizing, heating and stirring, controlling the reaction time to be 0.5-2.0 h, and controlling the heating temperature to be 190-260 ℃ to obtain ore pulp;

s2, filtering the ore pulp obtained by the oxygen pressure alkaline leaching in the step S1, filtering to obtain filter residue and leachate, returning the unreacted manganese metal powder contained in the filter residue to the oxygen pressure alkaline leaching process, cooling and crystallizing the leachate to obtain potassium manganate crystals, and returning the crystallized mother liquor to the oxygen pressure alkaline leaching process.

2. The method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder according to claim 1, characterized in that: in the step S1, the granularity of the metal manganese powder is less than 0.125mm, and the liquid-solid ratio is controlled to be 5-15: 1.

3. the method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder according to claim 1, characterized in that: in the step S1, the mass ratio of the metal manganese powder to the alkali is 1: 5 to 10, and the pressure in the kettle is 1.0 to 1.6 MPa.

4. The method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder according to claim 1, characterized in that: and in the step S1, the water is sterile purified water, and the outer surface of the autoclave is sleeved with a heat-insulating sleeve.

5. The method for preparing potassium manganate by pressure alkaline leaching of metal manganese powder according to claim 1, characterized in that: the chemical formula of the prepared potassium manganate is as follows: 2Mn +3O₂+4KOH＝2K₂MNO₄+2H₂O。

Technical Field

The invention relates to the technical field of potassium manganate preparation, in particular to a method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder.

Background

Potassium permanganate is an intermediate raw material for producing potassium permanganate, is a common strong oxidant, has wide application, and is industrially used as a disinfectant, a bleaching agent and the like. The prior potassium manganate production process comprises two major types of solid phase method and liquid phase method:

1. the solid phase method is divided into an open hearth method and a rotary hearth method. Spreading manganese powder on a flat furnace by using an open-hearth furnace method, wetting by using an alkaline solution, turning materials up and down by using a turning machine, adding caustic soda flakes in batches, reacting to generate solid potassium manganate particles, and leaching the potassium manganate by using weak alkaline water. The converter method is that pyrolusite and alkali liquor are mixed into slurry, which is sprayed into the first rotary kiln and exposed in the atmosphere for a short time to 300 deg.C, so that the mixture reacts but does not stick to the wall of the reactor, the product is cooled and ground, and in the second stage, the ground product is placed in another rotary kiln and air is introduced at 140 plus 250 deg.C for roasting for about 4 hours, so that the product is further oxidized into potassium manganate. The solid phase method has the problems of long process flow, high labor intensity, low production efficiency, poor continuity, great environmental pollution and the like;

2. the liquid phase method is classified into a classical liquid phase method, a liquid phase self-circulation three-phase fluidized bed method, a pneumatic fluidized tower method and a horizontal kettle pressure oxidation method. Compared with a solid phase method, the liquid phase methods have the advantages of short flow, short time, small environmental pollution, low material consumption and the like, but still have the problems of high adaptation difficulty of production equipment, low conversion rate of manganese dioxide, high quality requirement of manganese powder, high impurity content of products and the like.

Meanwhile, the traditional potassium manganate preparation process is open or semi-closed, a large amount of toxic gas is discharged, and the heat is also dissipated in a large amount.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder, which solves the problems of complicated process flow, low production efficiency, low product quality and environmental pollution of the existing method for preparing potassium manganate.

In order to achieve the purpose, the invention is realized by the following technical scheme: a method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder specifically comprises the following steps:

s1, selecting metal manganese powder, potassium hydroxide and water, adding the selected metal manganese powder, potassium hydroxide and water into a pressure kettle according to a certain proportion, introducing oxygen while adding the metal manganese powder, potassium hydroxide and water, pressurizing, heating and stirring, controlling the reaction time to be 0.5-2.0 h, and controlling the heating temperature to be 190-260 ℃ to obtain ore pulp;

s2, filtering the ore pulp obtained by the oxygen pressure alkaline leaching in the step S1, filtering to obtain filter residue and leachate, returning the unreacted manganese metal powder contained in the filter residue to the oxygen pressure alkaline leaching process, cooling and crystallizing the leachate to obtain potassium manganate crystals, and returning the crystallized mother liquor to the oxygen pressure alkaline leaching process.

Preferably, in the step S1, the particle size of the manganese metal powder is less than 0.125mm, and the liquid-solid ratio is controlled to be 5-15: 1.

preferably, the mass ratio of the metal manganese powder to the alkali in the step S1 is 1: 5 to 10, and the pressure in the kettle is 1.0 to 1.6 MPa.

Preferably, in the step S1, the water is sterile purified water, and an insulating sleeve is sleeved on the outer surface of the autoclave.

Preferably, the chemical formula of the prepared potassium manganate is as follows: 2Mn +3O₂+4KOH＝2K₂MNO₄+2H₂O。

Advantageous effects

The invention provides a method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder. Compared with the prior art, the method has the following beneficial effects:

(1) the method for preparing the potassium manganate by the pressure alkaline leaching of the metal manganese powder takes the metal manganese powder as a raw material, utilizes the favorable conditions of high temperature, high pressure, strong oxidizing atmosphere and the like of the oxygen pressure alkaline leaching process, has the manganese conversion rate of over 95 percent, and obtains a product with less impurity content compared with a horizontal kettle pressure oxidation method, thereby improving the product quality and the manganese conversion efficiency to a great extent.

(2) According to the method for preparing the potassium manganate by the metal manganese powder pressure alkaline leaching, the degree of automation of the pressure kettle of the oxygen pressure alkaline leaching process is high, so that the operation is simpler and more convenient, the labor intensity can be reduced, the production continuity is realized, and the production efficiency is improved to a great extent.

(3) The reaction is carried out in the pressure kettle, the pressure kettle has good tightness, and meanwhile, the heat insulation sleeve is sleeved, so that the heat dissipation amount is small, the heat utilization rate is high, no toxic or harmful gas is generated in the reaction process, and the environment pollution is basically avoided.

Drawings

FIG. 1 is a schematic flow chart of the operation of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, an embodiment of the present invention provides six technical solutions: a method for preparing potassium manganate by pressure alkaline leaching of manganese metal powder specifically comprises the following embodiments: