What is Tabular Alumina?
Tabular Alumina, sometimes called WTA, is a pure, sintered corundum that does not add any additives such as MgO, B2O3, and shrinks completely.
It has coarse crystals and a well-developed α-Al2O3 crystal structure.
The content of Al2O3 is more than 99%. Crystal structure, with small pores and many closed pores, and the porosity is roughly equivalent to that of Fused Alumina.
With high purity, good volume stability, and minimal re-fire shrinkage, Tabular Alumina performs good as the refractory materials or castables. Tabular Alumina has good thermal shock stability and bending strength after the production of high temperature treatment.
Production Process of Tabular Alumina：
Raw material
Use 60# Industry Alumina Powder normally imported from Australia, grint it into 380# fine powder by ceramic ball bill.
Making raw balls
Adding water into 380# fine powder, and put them into the ball tube to make the raw balls, its diameter is normally 2.4 cm min. The whole processing time needs about 3 hours.
Raw ball drying
Drying equipment: natural gas drying tower
Drying temperature: 400-500 ℃
Drying time: 20 hours
Drying standard: moisture 0.5% max
Raw ball sintering
Sintering equipment: natural gas shaft kiln
Sintering time: 22 hours
Sintering characteristics: rapid heating and cooling
Sintering process
Feed: Lift the dried raw balls to the top of the shaft kiln through the lifting device.
Warm up: The shaft kiln is divided into ten sections from top to bottom according to the temperature range, 10-1 from top to bottom.
The roof of the kiln is preheated-the tenth section is 100 degrees, and then it falls freely (the falling speed is controlled by the system).
High temperature sintering: In the sixth section, the temperature quickly rose to 1950 degrees (the highest temperature).
Wind-cooled: Air-cooled below the fifth section, the temperature of the sintered cooked balls is 400 degrees when they are out of the oven.
Tabular Alumina Sand making
Preparation for sand making: Use air-cooling treatment to cool the sintered raw ball below 100 degrees.
Sand making: Send the ready cooled raw balls to the Barmac sand making machine for crushing, sand making, magnetic separation (removal of iron filings from mechanical iron-equipment), sieving.
Milling: Ball milling into different size on request: 0.5-1 mm/ 0-0.5 mm/ 0.2-0.6 mm/ 0-0.2 mm/ 200 mesh/ 325 mesh/ 400 mesh etc.
