It should be noted that when the grinding products are required to be coarse, the variation of ultrafine vertical mill productivity with feed particle size is obvious, while when the grinding products are required to be fine, the variation of mill productivity with feed particle size is not very prominent.

When the feeding particle size, i.e. the grinding particle size, is small, the grinding fineness is easy to achieve. However, the fineness and productivity are contradictory.

However, for the coarse grinding process, the influence of the fineness change of grinding products on the mill productivity is not as obvious as that of fine grinding.

To sum up, in actual production, each concentrator should find out the suitable feeding particle size of the mill according to the scale of the concentrator and ore properties.