Bimodal active alumina micropowder and preparation method

Abstract

The invention discloses a preparation method for bimodal active alumina micropowder. The method comprises the following steps: (1) calcining industrial alumina powder at different temperatures so as to obtain calcined alumina powders with a variety of original crystalline sizes; (2) selecting two calcined alumina powders with different original crystalline sizes and carrying out ball milling so as to obtain the bimodal active alumina micropowder, wherein the mass ratio of the two calcined alumina powders with different original crystalline sizes is 0.2-5: 1. The preparation method for the bimodal active alumina micropowder provided by the invention is simple and can obtain bimodal-distribution active alumina micropowder; and the obtained bimodal alumina micropowder can be used for refractory products and can improve performances like construction performance, compactness, slag resistance and mechanical strength of the refractory products.

Description

technical field [0001] The invention relates to the field of refractory materials, in particular to a bimodal activated alumina micropowder and a preparation method thereof. Background technique [0002] Activated alumina powder is an extremely important refractory raw material, and its Al 2 O 3 The content is generally above 98%. Activated alumina micropowder is mostly made of industrial alumina as raw material, calcined at high temperature in a tunnel kiln (rotary kiln), and ground and classified. It has high purity, α-Al 2 O 3 It has the characteristics of high conversion rate, large true specific gravity, stable crystal form, narrow particle size distribution and good dispersibility. , epoxy resin casting filler, grinding, polishing abrasives, etc. [0003] As an important part of the matrix material in the refractory castable, activated calcined alumina micropowder has irreplaceable functions such as high temperature resistance and sintering promotion. The particl...

AI Technical Summary

Problems solved by technology

However, the technical solutions disclosed in these two patents have high production costs, and the particle size of alumina powder is concentrated. They are mostly used in high-end ceramic products such as catalyst carriers, and are not suitable for use as a matrix for castables.

[0009] The alumina micropowders in the prior art are mostly unimodal distribution, with concentrated particle size and high production cost, which is not conducive to improving the performance of castables. Therefore, in view of the shortcomings of traditional activated alumina micropowders, it is necessary to develop bimodal (active) Aluminum oxide powder

Images