The main factors influencing the spiral classifier classification process include ore properties, equipment structure, operation method.

1. Mud content and particle size of the sized feed
More mud contents and the fine particles in the sized feed, more greater the pulp viscosity is. Smaller settlement speed of the mineral particles in the ore pulp is, more coarse the granularity of overflowing. In this case, we need to increase the supplementary water suitably to reduce the pulp density, therefore ensuring the overflow fineness in line with the requirements. If less mud content in feeding process, or desliming processing, it’s required to improve the pulp concentration properly to reduce the excess fine fraction materials in the sand return process.

2. Mineral density and particle shape
In the same concentration and other conditions, smaller density of material classification is, bigger the pulp viscosity is. The granularity of overflowings will become more coarse. On the contrary, the greater density of material classification is, smaller pulp viscosity. The fineness of overflowing will become thinner, thus the fine fraction content increased in the sand return process. Therefore, when seperating the ore with great density, it’s required to increase the stage concentrations. due to flat ore particle settlement speed is slower than that of the circular or nearly circular mineral particles, so it needs to adopt the smaller pulp density, or to accelerate the dischargen speed of overflowing.

3. Angle of classifier trough
If the inclination of trough is small and settlement area of classifier is large, the granularity of overflowing will be fine, aslo the fine fraction content will increase in the sand return process. Conversely, if the inclination of trough is large and the settlement area is small, granulartiy of overflowing will be coarse and the fine particles will be less in the sand return process. The inclination will not move after the installation of the classifier. Therefore it’s required to consider the effect when installation.

4. Revoling speed of screw
If revolving speed is higher , production capacity calculated by the return sand quantity will be higher. Since the pulp mixing effect becomes stronger, coarse grain in the overflowings increased, which is applicable for coarse grinding cycle used in the classifier. If required the relatively fine overflowing, the rovolving speed of screw should be slow down a little.