In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a Mineral Processing Engineer AKA Metallurgist to do. Often, the ball used in ball mills is oversize “just in case”. Well, this safety factor can cost you much in recovery and/or mill liner wear and tear.
Vertical roller mill is a kind of grinding machine for cement raw material, cement clinker, slag and coal slag. It has the features of simple structure, low cost of manufacture and roller mill has many different forms, but it works basically the same.