The invention belongs to the technical field of porous ceramics, and discloses high-strength porous ceramics and a low-temperature preparation method thereof. The method comprises the steps: (1) mixing raw materials, wherein the raw materials include solid waste, low-grade minerals and an additive, and the raw materials also include an aluminum source when an aluminum element in the raw materialsis insufficient; (2) molding the mixed raw materials into green bodies; (3) firing the green bodies at the temperature of 800-1300 DEG C to obtain the high-strength porous ceramics, wherein the additive is one or more of alumina, nitrate, carbonate, sulfate, phosphate, fluoride and borax. The solid waste and the low-grade minerals are used as a part of the raw materials, the recovery and utilization of resources are realized, and the method is environmentally friendly and economical; the method has the advantages of wide range of the raw materials, simple process (one-step in-situ preparationof a whisker skeleton structure), and low production cost, and is suitable for industrial production. At the same time, the method has less energy consumption, and the prepared porous ceramics have the whisker skeleton structure and have the advantages of high porosity, low density and high mechanical strength.

High-strength porous ceramics and low-temperature preparation method thereof

The present invention discloses a method for preparing mullite crystal whiskers through in-situ growth of coal gangue and aluminum hydroxide under a dry pressing condition in the absence of V2O5 The method is characterized in that coal gangue and aluminum hydroxide are adopted as main raw materials, aluminum fluoride is additionally added as a catalyst, material mixing, dry ball milling, screening, spray granulation and souring are performed to obtain mullite crystal whisker precursor granules, and dry pressure pressing and normal pressure sintering to obtain the mullite crystal whiskers According to the present invention, the difficult problem that the dry pressure pressing process is used to prepare the mullite crystal whiskers with the large length-diameter ratio in the absence of V2O5 under the dry pressure condition is innovatively solved, and the great benefit is provided for the comprehensive utilization of the waste coal gangue resources and the reduction of the mullite crystal whisker production cost, such that the method has the high economic and social values

Method for preparing mullite crystal whiskers through in-situ growth of coal gangue and aluminum hydroxide under dry pressure condition in the absence of V2O5

The invention discloses a method for synthesizing mullite whisker by taking kaliophilite as a raw material. The method comprises the following steps: mixing mullite, deionized water, sulfuric acid andAl2(SO4)3 to obtain turbid liquid; adding the turbid liquid into a reaction still, putting the reaction still into a microwave hydrothermal reaction apparatus and carrying out hydrothermal reaction at the reaction temperature of 120 to 180 DEG C for 20 to 80 minutes; drying liquid in the reaction still after microwave reaction, then carrying out molten salt reaction, and washing a reacted productto obtain the mullite whisker. According to the method disclosed by the invention, the mullite as a raw material can be used as a precursor of the mullite whisker and can simultaneously provide molten salt substances for reaction, so that reaction cost is reduced and reaction procedures are simplified. Nanoscale oxide particles can be formed in a microwave hydrothermal system, the reaction temperature of molt salts is reduced, and whisker with high aspect ratio is favorably obtained. The preparation method disclosed by the invention has the advantages of low cost, low reaction temperature, simple process, good repeatability, high yield and the like.

Method for synthesizing mullite whisker by taking kaliophilite as raw material

The invention discloses a light low-expansion porcelain building ceramic tile and a preparation method thereof. The light low-expansion porcelain building ceramic tile has a composite structure comprising inner and outer parts. The outer part is a base blank dense layer and the middle part is a base blank-mullite whisker light layer so that the proportion of the material is reduced. The light low-expansion porcelain building ceramic tile solves the problem of poor surface density of a single porous structure. The outer layer is a compact layer so that material ceramization (wherein a water absorption is less than 0.5%) is realized, material strength is improved, and machinability and poor dirt resistance of the existing porous light material are improved. The preparation method is simple, has a low cost and has a broad market space.

Light low-expansion porcelain building ceramic tile and preparation method thereof

The invention relates to cylindrical mullite-sheet shape alumina composite powder and a preparation method thereof. The preparation method comprises the following steps: uniformly mixing 60-88wt% of mullite powder and 12-40wt% of aluminium fluoride powder to obtain mixed powder; adding deionized water in the mixed powder according to the mass ratio of (0.01-0.05):1, uniformly mixing the materials, ageing a mixture, and compacting the mixture to obtain a base substrate; then placing the base substrate in an enclosed alumina crucible, insulating the material for 2-16 hours at the condition of 1400-1650 DEG C, and cooling the material to room temperature to obtain the cylindrical mullite-sheet shape alumina composite powder. The Al2O3 content in the mullite powder is greater than or equal to 71.8wt%, and particle size is less than or equal to 80 mm. The AlF3 content in the aluminum fluoride powder is greater than or equal to 98wt%, and particle size is less than or equal to 80 mm. The cylindrical mullite-sheet shape alumina composite powder has the characteristics of simple preparation technology, easiness in control, low cost and high yield; and the cylindrical mullite-sheet shape alumina composite powder produced by the method has the advantages of high purity and easy large-scale production.

Cylindrical mullite-sheet shape alumina composite powder and preparation method thereof

The invention discloses a preparation method for utilizing desert sand to synthesize mullite whiskers at the low temperature. The desert sand, aluminium hydroxide and bauxite are used as main materials, AlF and V O are added to serve as additives, and the mullite whiskers are obtained through blending, dry grinding, mixing, smashing, screening and buried combustion. By means of the preparation method, the preparation cost of the mullite whiskers is remarkably reduced, and comprehensive resource utilization of the desert sand is promoted. Therefore, the preparation method has higher economic and social values.

Preparation method for utilizing desert sand to synthesize mullite whiskers at low temperature

The invention discloses a preparation method for synthesizing mullite whiskers through adopting borides as additives. According to the method, desert sands and aluminium hydroxide are adopted as the main raw materials, with addition of borax and boric acid as additives, mullite whiskers are obtained through burdening, dry grinding and mixed smashing, sieving and calcining. Borax and boric acid, rather than traditional synthesis auxiliaries of AlF3 and V2O5, are used as additives for promoting synthesis of mullite whiskers, so that the production cost of mullite whiskers is greatly reduced, and the preparation method has greater economic and social values.

Gu Xingyong

Papers

Preparation method for utilizing desert sand to synthesize mullite whiskers at low temperature

Preparation method for synthesizing mullite whiskers through adopting borides as additives

Light low-expansion porcelain building ceramic tile and preparation method thereof