Super Fine Grinding

Super Fine Grinding

 Super Fine Grinding Plant

Super Fine Grinding Plant

In China, most of the iron ore grinding processes adopt two-stage grinding process, and most of the small and medium-sized concentrators adopt one-stage grinding process. In recent years, some ore dressing plants have been changed from two stages of grinding to three stages of grinding because of the new technology of fine screening and regrinding. The grinding equipment used is generally small, the maximum ball mill is 3.6m *6m, the maximum rod mill is 3.2m *4.5m, the maximum autogenous mill is 5.5m *1.8m, and the gravel mill is 2.7m *3.6m. Grading after grinding is basically a spiral classifier. In order to improve efficiency, some concentrators use hydrocyclones instead of the two spiral classifier.

Grinding operation is the continuation of ore crushing process, and it is also an important part of preparatory work before separation. It is usually carried out in the grinding mill, and the grinding mill is equipped with grinding media. If the medium is steel ball, it is called ball mill; if the medium is steel bar, it is called bar mill; if the medium is gravel, it is called gravel mill. If their own ore as a medium, it is called self-grinding machine; ore self-grinding machine added to the appropriate amount of steel balls, it constitutes the so-called semi-self-grinding machine. The specifications of the mill are represented by the length of the diameter of the simplified X. The grinding operation is mainly wet grinding, and generally forms a closed-circuit cycle with the mechanical classifier. But for water-deficient areas and some water-repellent process (such as cement plant, asbestos plant production process or some dry process), it is also used in Tangshan mine.

The spiral classifier is based on the principle of different particle sizes and specific gravities, and thus different settling velocities in liquids. Fine ore particles float in the water and overflow, and coarse ore particles sink at the bottom of the trough. A grading device that is pushed upward by a screw to perform mechanical grading. The grinding powder in the mill is filtered, and then the coarse material is rotated into the inlet of the mill by a screw disc, and the filtered fine material is discharged from the overflow pipe.

Floatation, namely foam flotation, is based on the difference in surface properties of various minerals and the process of separating minerals from the pulp by means of buoyancy of bubbles. The pulp of a certain concentration is mixed with various flotation reagents to produce a large number of dispersed bubbles by agitation and aeration in the flotation machine. At this point, suspended particles collide with bubbles. Some of the buoyant particles are attached to the bubble and float to the liquid surface to form foam products, usually concentrate. Non floating minerals remain in the pulp, usually tailings, so as to achieve the purpose of separation. Whether minerals can be separated from each other depends on whether they can selectively adhere to bubbles and float to the pulp surface.