阅读说明：本技术 一种利用废硅藻土制备莫来石粉体的方法及基于该方法所制备的莫来石粉体 (Method for preparing mullite powder from waste diatomite and mullite powder prepared based on method ) 是由 陈凤 于 2019-11-29 设计创作，主要内容包括：本发明公开了一种利用废硅藻土制备莫来石粉体的方法及基于该方法所制备的莫来石粉体,所述莫来石粉体是以废硅藻土为主要原料,再添加适量的含铝离子的溶液,采用高温自蔓延燃烧方法制备而来；本发明以废硅藻土为主要原料制备莫来石粉体,实现了变废为宝,使得废硅藻土不再是污染环境的废弃物,而成为一种高价值的资源,具有显著的经济效益和社会效益；本发明制备方法简单,得到的莫来石粉体是一种具备良好结晶性能的非金属粉体材料,均匀性好,晶粒小,可广泛地应用于制备耐火材料和陶瓷材料中。(The invention discloses a method for preparing mullite powder by using waste diatomite and the mullite powder prepared by the method, wherein the mullite powder is prepared by using the waste diatomite as a main raw material, adding a proper amount of solution containing aluminum ions and adopting a high-temperature self-propagating combustion method; the mullite powder is prepared by taking the waste diatomite as a main raw material, so that waste is changed into valuable, the waste diatomite is not a waste polluting the environment any more, and the mullite powder is a high-value resource and has obvious economic and social benefits; the preparation method is simple, and the obtained mullite powder is a nonmetal powder material with good crystallization performance, has good uniformity and small crystal grains, and can be widely applied to preparation of refractory materials and ceramic materials.)

1. A mullite powder is characterized in that: the mullite powder is prepared by taking waste diatomite as a main raw material, adding a proper amount of solution containing aluminum ions and adopting a high-temperature self-propagating combustion method.

2. The mullite powder of claim 1, wherein: the mass ratio of the silicon element in the waste diatomite to the aluminum ion added in the aluminum ion solution is 1: 3.

3. A method for preparing mullite powder by using waste diatomite is characterized by comprising the following steps:

(1) mixing waste diatomite and a solution containing aluminum ions, wherein the mass ratio of silicon elements in the waste diatomite to substances added with the aluminum ions in the aluminum ion solution is 1:3, putting the mixture into a planetary ball mill for wet ball milling, controlling the ball-material ratio of grinding balls to raw materials to be 2 ~ 3:1, controlling the rotating speed to be 300r/min, and ball milling for 4h 4 ~ 6h to obtain slurry;

(2) adding fuel into the slurry, stirring, transferring into a heating furnace at 500 ~ 800 deg.C, igniting, and burning to obtain fluffy powder;

(3) and (3) carrying out heat treatment on the fluffy powder for 2 ~ 4h at 1200 ~ 1350 ℃ in an air atmosphere to obtain the mullite powder.

4. The method for preparing mullite powder from waste diatomite as claimed in claim 3, wherein the method comprises the following steps: the solution containing aluminum ions is obtained by dissolving one or more of aluminum nitrate or aluminum sulfate or aluminum chloride in water.

5. The method for preparing mullite powder from waste diatomite as claimed in claim 3, wherein the method comprises the following steps: the fuel is one or more of urea, citric acid or ethanol.

6. The method for preparing mullite powder from waste diatomite as claimed in claim 3, wherein the method comprises the following steps: the fluffy powder is subjected to heat treatment for 3 hours at 1350 ℃ in an air atmosphere.

Technical Field

The invention relates to the technical field of preparing ceramic powder materials by using solid wastes, in particular to a method for preparing mullite powder by using waste diatomite and the mullite powder prepared based on the method.

Background

Mullite (3 Al)₂O₃·2SiO₂) Is Al₂O₃-SiO₂The system is a unique and stable crystalline compound under normal pressure, has high refractoriness, good thermal shock resistance, chemical erosion resistance and creep resistance, high refractoriness under load, good volume stability, strong electrical insulation and the like, is an ideal high-grade refractory material, and is widely applied to the fields of metallurgy, glass, ceramics, chemistry, electric power, national defense and the like. However, natural mullite minerals are rare in nature, and industrial mullite is mainly usedAnd (4) artificial synthesis.

At present, the methods for synthesizing mullite for industrial use mainly include an electric melting method and a sintering method. The electric melting method is formed by melting the mixed raw materials in an electric arc, and has the defects of high power consumption and strict requirements on synthesis conditions; sintering processes are classified into inorganic silica-alumina gel processes, organic silica-alumina gel processes, and mineral phase change processes according to the nature of the raw materials used. Wherein, the inorganic silicon-aluminum gel method and the organic silicon-aluminum gel method are respectively prepared by adopting inorganic and organic raw materials according to certain chemical compositions and then are calcined at high temperature, and have the defects of higher energy consumption and expensive price of the organic raw materials used in the organic gel method; the mineral phase transition method is formed by placing natural minerals such as high bauxite, kaolin, pyrophyllite and the like in a kiln and calcining at high temperature, and has the defects of high energy consumption, low mullite conversion rate and resource waste due to the fact that the mineral composition of the mullite is greatly different from that of the mullite.

Diatomite is a natural mineral raw material deposited from dead bodies of ancient biological diatoms, has the characteristics of light weight, good chemical stability, high porosity, wear resistance, acid resistance, heat resistance, strong adsorbability and the like, is used as a filter aid, a filling agent, a catalyst carrier and the like, and is widely applied to various industrial departments. A large amount of diatomite loses activity after being used and is stacked near a factory building or in a drainage ditch, so that the environment is polluted, and the renewable resources which can be used are wasted. Therefore, it is an important content of the present invention to research a method for preparing mullite powder from waste diatomite.

Disclosure of Invention

The invention aims to provide a method for preparing mullite powder by using waste diatomite and mullite prepared based on the method, aiming at solving the problems that the mullite synthesized by using a capacitance method at present has large power consumption and strict requirements on synthesis conditions, and a sintering method has high energy consumption, high cost, low mullite conversion rate and the like.

In order to realize the purpose, the invention is realized by the following technical scheme:

the mullite powder provided by the invention is prepared by taking waste diatomite as a main raw material, adding a proper amount of solution containing aluminum ions and adopting a high-temperature self-propagating combustion method.

Preferably, the mass ratio of the silicon element in the waste diatomite to the aluminum ion added in the aluminum ion solution is 1: 3.

The invention relates to a method for preparing mullite powder by using waste diatomite, which comprises the following steps:

(1) mixing waste diatomite and a solution containing aluminum ions, wherein the mass ratio of silicon elements in the waste diatomite to substances added with the aluminum ions in the aluminum ion solution is 1:3, putting the mixture into a planetary ball mill for wet ball milling, controlling the ball-material ratio of grinding balls to raw materials to be 2 ~ 3:1, controlling the rotating speed to be 300r/min, and ball milling for 4h 4 ~ 6h to obtain slurry;

(2) adding fuel into the slurry, stirring, transferring into a heating furnace at 500 ~ 800 deg.C, igniting, and burning to obtain fluffy powder;

(3) and (3) carrying out heat treatment on the fluffy powder for 2 ~ 4h at 1200 ~ 1350 ℃ in an air atmosphere to obtain the mullite powder.

Preferably, the solution containing aluminum ions in the present invention is obtained by dissolving one or more of aluminum nitrate or aluminum sulfate or aluminum chloride in water.

Preferably, the fuel in the present invention is one or more of urea or citric acid or ethanol.

Preferably, the fluffy powder is heat treated at 1350 ℃ for 3h in an air atmosphere.

The invention has the beneficial effects that:

(1) the mullite powder is prepared by taking the waste diatomite as a main raw material, so that waste is changed into valuable, the waste diatomite is not a waste polluting the environment any more, and the mullite powder is a high-value resource and has obvious economic and social benefits.

(2) The mullite powder prepared by the method is a nonmetal powder material with good crystallization performance, and can be widely applied to preparation of refractory materials and ceramic materials.

(3) The invention adopts a high-temperature self-propagating combustion method, utilizes the characteristic that the waste diatomite contains high grease and organic matters, and additionally adds fuel, so that once the waste diatomite is ignited under the low-temperature condition, the heat generated by combustion is enough to maintain the combustion, and the waste diatomite does not need to be heated by an additional heat source. The heat released by continuous self-propagating combustion is utilized to enable the silicon source and the aluminum source to react to generate mullite, so that the method not only saves energy, but also has the advantages of high reaction speed, low reaction temperature, capability of being carried out under normal pressure and the like.

Drawings

FIG. 1 is a microscopic topography of waste diatomaceous earth;

FIG. 2 is an XRD spectrum of waste diatomaceous earth;

FIG. 3 is an XRD pattern of mullite powder prepared in example 1 of the present invention;

FIG. 4 is a microscopic morphology of mullite powder prepared in example 1 of the present invention;

FIG. 5 is an XRD pattern of mullite powder prepared in example 2 of the present invention;

FIG. 6 is an XRD pattern of mullite powder prepared in example 3 of the present invention;

fig. 7 is an XRD pattern of mullite powder prepared in example 4 of the present invention.

Detailed Description