White spot of Brown fused alumina

- Aug 31, 2018-

White spot of Brown fused alumina 

  • Brown fused alumina is a kind of artificial corundum produced by high temperature smelting of natural bauxite. Although the main component is Aluminium Oxide, it still contains a lot of other chemical components such as silica, iron oxide, titanium oxide, etc. Although these contents will affect the abrasive and refractory properties, but also to a certain extent the application is beneficial, such as titanium oxide can increase its toughness. And these secondary components can not be completely removed. So these are not within the scope of this discussion. The discussion in this article refers to the impurity formation during grading process by external contamination or white and wood chips, and the dust produced in the process of crushing/mill.White Spot

White Spot refers to the white impurity in brown fused alumina granularity in the smelting process, formed in brown fused alumina. Bauxite mine and smelting process to add iron and anthracite raw material itself will contain various impurities, and chemical reaction will also produce some impurities in high temperature smelting process of electric arc furnace. Among them, the white spots are most visible to the naked eye. These impurities will affect the effective components of brown fused alumina, have a certain impact on the grinding performance and fire resistance, and the appearance is not too beautiful to affect the feelings of the end user. In particular, some of the fine grinding industry which require high standard, these impurities may make the final product defective. It is difficult to completely remove these white impurities, because it is produced in the smelting process, the number of brown fused alumina will have a certain amount of content. In the actual production, mainly through the following methods to reduce the white spots.

1; Optimization of raw materials and smelting and refining to improve the crystallization effect of corundum, from the source to make brown fused alumina more dense, less impurities

2, In the process of crushing by manual sorting, as far as possible the selection of less impurities in the original block for crushing silt. But this method consumes manpower, high cost

3; Multiple magnetic separation can remove the impurities which contain more iron and magnetism