Grinding

QMAG’s grinding processes produce the feed material for deadburned and calcined magnesia products that are attractive to multiple different markets. These products require the coarser calcined magnesia to be finely ground to meet size specifications. This process not only makes it easier to sinter the product during deadburned magnesia production, but also increases final product density. It also significantly improves the reactivity of the milled calcined magnesia products.

We have three Raymond roller mills that process our calcined magnesia in a range of sizes. We use an air classifier on top of the mill to control the grind size. Particles inside the mill that are larger than the required size cannot exit the mill through the classifier and are subsequently ground further. We collect and analyse samples every day to check the grind performance of the mill and to ensure the end product meets the necessary particle size.

After grinding, the magnesia has two possible destinations. It can be sent for briquetting, to be processed through the vertical shaft kilns (VSK) to end up as deadburned magnesia. Or if there is no further processing, it is sold as caustic calcined magnesia and is sent to the CCM area for finished product bagging or containerising.