Microporous magnesium-chromium spinel raw material and preparation method thereof

Abstract

The invention relates to a microporous magnesium-chromium spinel raw material and a preparation method thereof. According to the technical scheme, the preparation method comprises the following steps: adding magnesium oxalate and chromium carbide into a ball mill in a mass ratio of (1.1-1.15) to 1, and carrying out ball milling until the particle sizes are less than or equal to 100 microns, so as to obtain ball-milled powder; putting the ball-milled powder into a drying oven, and maintaining the temperature at 200-250 DEG C for 30-40 minutes, so as to obtain thermally processed powder; adding water which accounts for 15wt%-20wt% of the thermally processed powder into the thermally processed powder, carrying out wet milling in the ball mill until the particle size is less than or equal to 60 microns, so as to obtain a wet-milled material; and adding the wet-milled material into a mud refining machine, carrying out vacuum mud extrusion molding, and standing for 24-36 hours; putting the processed material into a muffle furnace, maintaining the temperature at 1550-1600 DEG C in an air atmosphere for 3-4 hours, carrying out furnace cooling, and crushing, so as to obtain the microporous magnesium-chromium spinel raw material. The preparation method is simple and low in production cost; the prepared microporous magnesium-chromium spinel raw material is good in sintering performance, high in spinel conversion rate and low in heat conductivity coefficient.

Description

technical field [0001] The invention belongs to the technical field of magnesia-chrome spinel. It specifically relates to a microporous magnesia-chromium spinel raw material and a preparation method thereof. Background technique [0002] Magnesium chromium spinel (MgO Cr 2 o 3 ) are MgO and Cr 2 o 3 A type of solid solution formed after high temperature treatment. Magnesium-chromium spinel has both MgO and Cr 2 o 3 It has the advantages of high melting point, high temperature strength, strong chemical corrosion resistance and good thermal shock stability. It is widely used in high temperature furnaces such as refining ladles, copper smelting converters and electric furnaces. [0003] The existing preparation methods of magnesia-chromium spinel mainly include molten salt method, electric melting method and sintering method. [0004] Magnesium-chromium spinel is prepared by molten salt method, mainly using chromium-containing salt and magnesium-containing minerals as r...

AI Technical Summary

Problems solved by technology

However, using the molten salt method to wash and remove the remaining molten salt requires a large amount of water and energy, and the cost is high, which hinders the large-scale industrial production of the molten salt method.

[0005] The preparation of magnesia-chromium spinel by electric melting method is mainly to add chromium-containing salt and magnesium-containing salt into a high-temperature electric furnace, and cool after melting. High temperature, complicated process and high energy consumption greatly increase the preparation cost of magnesia-chromium spinel

[0006] The sintering method to prepare magnesia-chromium spinel, although the process is simple, but it is difficult to control the grain boundary migration and grain growth during the sintering process, such as "a raw material for synthesizing mullite and its preparation method" (CN 201310437815.1) and "using titanium Iron slag-based regenerated high-alumina refractory raw material and its preparation method” (CN 201410161089.X) resulted in incomplete grain growth and many defects, so the sintering performance of magnesium-chromium spinel was poor, and spinel low conversion rate