1. Dense-medium coal preparation technology

Dense-medium coal separation is a gravity coal separation method that uses heavy liquid or resuspended liquid with a density greater than water and between coal and gangue as a medium to achieve separation. Depending on the medium used, it can be divided into two categories: heavy liquid coal preparation and resuspension coal preparation. According to the different sorting conditions, the heavy medium sorting can be divided into two categories: sorting in the gravity field and sorting in the centrifugal force field. The former is mainly used for the separation of lump coal (more than 13mm), and the separation is carried out in a heavy mass separator, and the latter is mostly used at the end of the separation, and the separation is realized by a heavy medium cyclone.

Dense-medium coal preparation is a coal preparation method with higher separation efficiency at present, and its characteristics are:

1. Wide adjustment range of sorting density. The sorting density of heavy-medium sorting is generally 1300～2200kg/m3, and it is easy to adjust, and its error can be kept within ±0.5%.

2. Strong adaptability, wide range of sorting granularity. Dense medium coal preparation allows large fluctuations in the particle size, quantity and quality of the selected raw coal. For example, the feed size limit of the lump coal separator is 1000-6mm, and the fine coal heavy medium cyclone is 50-0.15mm.

3. The production process is easy to realize automation. The process parameters such as the density, liquid level, viscosity, and magnetic content of the suspension used in heavy medium coal preparation can be automatically controlled.

2. Jigging coal preparation technology

Jigging coal preparation refers to the material in the vertical pulsating medium, according to its physical and mechanical properties (mainly according to density) to realize the stratification and gravity coal preparation method, the material is continuously jigging on the fixed moving screen. The combined action of flushing water, top water and horizontal flow of the bed is sorted under the combined force of vertical and horizontal flow.

Jigging coal preparation is the main coal sorting process, which has the advantages of simple process flow, convenient equipment operation and maintenance, large processing capacity and sufficient sorting accuracy. It is mainly used for washing and selecting coal types that are difficult to select and easy to select. For difficult-to-clean coal, the jigging method and the heavy-medium method should be compared economically and technically to determine which technical method to choose. At present, jigging coal preparation technology continues to be carried out at home and abroad. Therefore, for a long time in the future, jigging will still occupy an advantageous position in our coal preparation industry.

3. Flotation coal separation technology

The separation of mineral particles by the flotation process makes full use of the difference in physical and chemical quality of the mineral surface, and its application is very wide. With the advancement of modern technology, flotation technology is constantly improving, such as carrier flotation and selective flocculation flotation, biological flotation, flotation column technology innovation, etc., which play an important role in improving the flotation efficiency of coal mines with different properties. .

In recent years, the development of coal preparation technology in my country has tended to diversify. The basic trend is to increase the size of coal preparation equipment, heavy-medium technology accounts for the main market, assembly type has become a new mode of coal preparation plant construction, coal preparation process automatic control and the level of automation of the whole plant Continuous improving.

A comprehensive understanding of modern coal preparation technology is a more economical and effective way to improve coal utilization efficiency and reduce pollutant emissions in coal preparation plants. It is worthy of the attention of the majority of coal preparation plants.