Reasons and solutions for black spots in calcined alumina

The surface of calcined alumina may present some black spots, just like food has become moldy. Can such calcined alumina products still be used normally? How can these black spots be removed? Aluminum oxide manufacturers are here to popularize the causes and solutions of black spots.

1、 Reason:

The production process of calcined alumina is very complicated, and the production equipment is messy. Iron equipment is prone to corrosion and rust, resulting in some black spots. It is then packaged and stored together with aluminum hydroxide. Another contributing factor is the raw material bauxite, which contains not only high levels of aluminum oxide, but also trace elements such as iron oxide, silicon oxide, and potassium oxide. During the differentiation process of aluminum ore, various trace elements are mixed and crystallized to form hard small black spots. The larger shaped black spots are filtered out, and the smaller ones are packaged and stored with the finished product.

2、 Solution:

1. Increase iron removal process in production to remove excess iron oxide and reduce the probability of black spots appearing.

2. Adding a certain amount of potassium permanganate solution during the differentiation process of calcined alumina aluminum ore can effectively inhibit the growth of black dot crystals and control them within a small range.

3. Use a small mesh to filter out larger black spots.

The primary reason for the formation of black spots in calcined alumina is the differentiation of the ore and the occurrence of rust. We can clean the black spots by filtering and adding potassium permanganate solution, and then put them into production.

The above is the reason and solution for the black spots on calcined alumina. If you have a demand for calcined alumina or other chemical products, please feel free to call for consultation or leave an online message.