How is ore sorted?

In order for the ore enrichment process to be successful, it must meet certain requirements. The main thing is a certain size. This factor is also related to other indicators. For example, the elements contained in the ore, their chemical compounds, the physical properties of the components, etc.

To enrich ore with high quality, you need to correctly perform several steps. One of the most important is the sorting of ore materials. This process begins with manual sorting. The main goal at this stage is to remove large-sized rock from the materials sent along the conveyor. First of all, this way you can get rid of those ore bodies that lack valuable components. This method is suitable if the ore size exceeds 40 mm. To ensure that nothing is missed during the process of studying the rocks, the conveyor used to sort the ore is subject to vibrations.

In order to sort the ore after manual sorting is completed, screens must be used. This is the name of special equipment that significantly facilitates the task. Screens come in different designs. For sorting small rocks, roller and vibrating structures are used, for medium-sized rocks, drums are used, and for large rocks, grate structures are used.

Preliminary sorting of bulk materials is carried out using a grate structure. It is suitable if their size is up to 1200 mm. In Figure 1 you can see what the rumble looks like. The device is a grate consisting of horizontal grates or located at a certain angle to the horizon, having a shaped cross-section. In a number of cases, cantilever fastening of the screen components is observed. Thanks to the trapezoidal section, pieces cannot get stuck in the hole of the device. There are gaps between the grates — 50-200 mm. The width of the device is affected by the size of the rock. To prevent large pieces from getting stuck between the grates, the width of the grate should be three times the dimensions of the largest body. In the case of sorting coal, the grate should be at an angle of 30-35 degrees, and ore — 38-50 degrees.

The drum screen takes the form of a rotating cylinder. The walls are made of steel mesh. The drum is used to load ore rock. It rotates — pieces of certain sizes pass along the conveyor belt for further processing, while larger ore remains in the screen. At the end of the device’s operation, large pieces must be removed and re-grinded.

The vibration structure consists of vertically arranged mesh plates that are subject to vibration. The rock to be sorted is placed on the top layer. Then the material of the appropriate size enters the screen, and then, along the lower tray, it is already on the conveyor with sorted ore. If there is any rock left in the upper tray of the device, it is sent for further grinding.