Molding sintering process of alpha-alumina

Abstract

The invention relates to a molding sintering process of alpha-alumina. The process comprises the following steps: (1) grinding the alpha-alumina material to 325-800 meshes; (2) adding a binder, an auxiliary material and a mineralizer in the alpha-alumina material during the grinding, mixing, then putting the mixed materials in a pug mill, and simultaneously adding explosion-proof fibers and pore forming agents of carbon powder, then adding a cellulose solution and water, mulling to get plastic mud; (3) putting the mud in a roll press, rolling the mud into thin plate blanks with several holes, wherein thickness of thin plate is 30-50mm; (4) drying the thin plate blanks through cutting, stacking the blanks on a kiln car, pushing the kiln car into a kiln for sintering the blanks, thereby acquiring alpha-alumina.

Description

technical field [0001] The invention relates to a manufacturing process of a refractory material, in particular to a forming and sintering process for calcining α-alumina by a hollow thin plate forming method. Background technique [0002] α-alumina is in the form of white powder, and its crystal form is α-type. In the crystal lattice of α-type alumina, oxygen ions are hexagonally packed tightly, and A13+ is symmetrically distributed in the octahedral coordination center surrounded by oxygen ions. The lattice energy is very large, so the melting point and boiling point are very high. α-type alumina is insoluble in water and acid, and can be used to make structural ceramics such as various refractory bricks, refractory crucibles, refractory pipes, and high-temperature-resistant experimental instruments; it can also be used as abrasives, flame retardants, fillers, etc.; high-purity The α-alumina is also the raw material for the production of artificial corundum, artificial ru...

AI Technical Summary

Problems solved by technology

This kind of calcination method has relatively high requirements for temperature control. If the calcination temperature is too high, too low or unstable, the structure of the product will change and cause quality fluctuations.

The production cost of rotary kiln calcined α-alumina is relatively low, the output is large, and it is more suitable for the production of bulk products, but there are also significant defects: the conversion agent is difficult to discharge after volatilization at high temperature, and it is enriched in a large amount in the kiln, indirectly increasing the material The amount of mineralizer used increases the difficulty of controlling the primary grain size of α-alumina; moreover, due to the dynamic spiral movement of the material in the kiln, there is a scouring effect of the material on the kiln lining, which is likely to bring kiln Lining falls off and causes pollution to materials, especially in high temperature areas.

However, its main defect is that the production cost is relatively high, which is mainly caused by reasons such as the cost of the sagger and the loss of waste heat.