Fundamental Principles Adhere to in Model Selection of Grinding Equipment

Processing capacity of ball mill and rod mill is relevant to grindability, granularity, model and size of lining board, the shape, size and physico -mechanical properties of grinding medium, slurry filling rate, concentration of ore, the type of classifier and its working system. Since there are many factors affecting the processing capacity of grinding mill, theoretical formula accurately calculating it hasn't been generated. The processing capacity is usually determined by experience and experiment. The processing capacity of ball mill and rod mill is generally calculated by the volumetric method and power loss method.

The following demands need to be fulfilled in grinding machine selection：

（1）Rod mill is often used for coarse grinding of material with granularity of 1-3mm. If the granularity is too small, the grinding efficiency will drop dramatically. Due to the effect of rod mill movement in the machine, the diameter should not be greater than 4,500mm, and the length of rod mill should not be more than 6,000mm. When ball mill and rod mill work jointly, the proportion should be 1:2.

（2）Grate ball mill is often used as the first stage mill for coarse grinding. When the grate mill works in a closed circuit, the granularity is usually within the range of 0.005-0.074mm. The ball mill is often matched by spiral classifier.

（3）Overflow ball mill can be often used for the first stage grinder as well as the second stage grinder. Occasionally, it can be used for regrinding of semi-finished product. At present, it is mostly used as the second stage grinder or middle product regrinder at home. And the classier is often configured with hydrocyclone. Sometimes, the grinder is also complemented by spiral classifier when used as first stage grinder. Heave type ball mill forms a circuit by overflow ball mill and hydrocyclone, which simplifies the structure and makes for easy check.

（4）When selecting autogenous mill, semi-autogenous mill and gravel mill,...