The technical-economic indicator of screening process are screening efficiency and productivity. The former is quality index, the latter is quantity index. There is a relationship between those two indexes,

We need to make sure what factors will affect the screening process before purchasing a vibrating screen. Those factors can be classified into three categories.

1. Physical properties of bulk material:

Particle size composition, humidity, mud content and particle shape of bulk material. High content of fine grain result in high screening productivity. Large moisture content of materials leads to low screening productivity. However, the larger the mesh size, the smaller the effect of moisture content. Therefore, for wet materials with larger moisture content, in order to improve the screening process, we can increase the mesh size or use wet screening instead. Materials with high mud content (when the mud content is greater than 8%) should be wet screened or pre-washed.

2. Influence of screen deck properties and structural parameters:

The vibrating screen is designed to produce vertical motion between the material and the screen deck result in high screening efficiency and large productivity. For certain material, the productivity and screening efficiency depend on the size of the mesh. Productivity depends on screen width, the wider the screen, the higher the productivity. The screen efficiency depends on the screen length, the longer the screen surface, the higher the screen efficiency. Generally, the length-width ratio is 2. The larger the effective screen area (i.e. the ratio of the mesh area to the entire deck surface area), the higher the unit area productivity and screening efficiency. The larger the size of the mesh, the greater the productivity of the unit screen deck, the higher the screening efficiency.

3. The effect of production conditions:

When the load of vibrating screen is large, the screening efficiency is low. To a large extent, the screen productivity depends on the size of the mesh and the total screening efficiency. The larger size of the mesh with the lower required screening efficiency, the higher the productivity.