It is found that within a certain range (such as 100% ~ 500%), the productivity of Raymond mill will increase with the increase of sand return ratio.

When a certain value is reached, the productivity increase will gradually decrease, and the total ore feeding capacity of Raymond mill is close to its upper limit. If the sand return ratio is forcibly increased at this time, it is easy to cause Raymond Mill "swelling".

Therefore, the sand return ratio should be kept stable and close to a constant value, which not only obtains the ideal productivity, but also reduces the energy consumption. Raymond mill operating principle 3: high concentration the so-called "high concentration" refers to the high percentage of ore weight in the whole pulp weight.