Tabular Alumina is made by a sintering process that quickly heats and cools alumina.
This processing method can make alumina with these features:
- high density
- high refractoriness
- low water absorption
- low porosity
1.Milling the raw materials
The tabular alumina from Haixu Abrasives uses 60# Australian alumina powder as the raw material. First, the raw materials are ground in a ceramic ball mill to obtain an alumina fine powder of 380 mesh. The ceramic balls in the milling equipment will avoid iron remaining in the raw materials, ensuring the purity of the alumina raw materials.
2 . Making raw balls
Add water to the 380 mesh fine powder and put it into a ball bucket to make alumina balls. Produce raw alumina balls with a diameter of not less than 2.4cm.
3. Raw ball drying
The raw alumina balls enter the drying tower for drying. The temperature of the countercurrent hot air in the drying tower can reach 400-500°C, which can remove about 15% (w) of moisture. After drying, the standard moisture content is within 0.5%. Our company strictly controls this processing procedure to avoid cracks, delamination, agglomeration in the balls.
4.Sintering raw alumina balls
Sintering the raw alumina balls in a shaft kiln. The sintering shaft kiln consists of ten sections, and the temperature of each section is of a specified temperature. The raw balls pass through the shaft kiln from top to bottom. The process is sintering from cold to hot, and then from heat to cold. The crystals of tabular alumina will fully develop. This process is the key process to form the crystal structure of the tabular alumina. The sintered alumina balls are called sintered balls.
5.Crushing sintered alumina balls to make sand
Firstly cool the sintered balls after coming out of the shaft kiln. And then enter the Barmac milling machine for crushing. After that, it goes with magnetic removing, and sieving processes. At last, get different sizes of tabular alumina section sands. For tabular alumina powder, there will be an extra milling process to get different sizes of powder.
Haixu Abrasives rationally designs the quality control system for production. We take random inspections for each process.
After the production is completed, we take full inspection for the following items:
- chemical composition
- particle size distribution
- density
- water absorption
- other physical and chemical indicators
As a result, it will get a good and stable tabular alumina quality.