From our Ore to Your Door - Episode 15: Grinding

QMAG’s grinding processes produce the feed material for deadburned magnesia, as well as calcined magnesia products that are attractive to many different markets. These products require the coarser calcined magnesia to be finely ground to meet size specifications. This process improves the sinterability during deadburned magnesia production, increasing 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 to end up as deadburned magnesia. 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.

Pictured: Leticia Shields, Parkhurst Production Coordinator