Crushing process is a significant procedure whether in the primary processing of raw coal or in the process of coal preparation. It directly affects the coal sale and the subsequent processing investment, and influences the economic benefits of coal enterprise. With the further development of market economy and improvement of coal preparation technology, the new requirments for the traditional crushing process are putting forward from the following aspects:
1.1
Coal user is very strict to the requirements of products granularity, different user has different requirement, and changing with the market development. Once the requirements cannot be reached, it will appear the phenomenon of dull sale or the user refuse to pay due to unsuitable granularity, which will affect the economic benefits of coal enterprise. Moreover, the price subjects to the different granularity at different time, so the enterprise must rely on the effective crushing process to obtain the largest benefits.
1.2 Deep processing to meet the demand of clean coal
In order to separate gangue from coal, increase the surface area of raw material, improve coal quality (lower ash content, higher calorific value), remove the harmful materials such as sulfur and phosphorus contained in the coal, reduce the atmosphere pollution during burning, we must carry out effective crushing operation.
1.3 Demand of coal washing machine
Different coal washing machine with different granularity range, it must through crushing operation to meet the demands of washing machine. For example: Dense medium cyclone is the high efficiency washing machine with strong adaption, being easy to realize automation and widely used in many places. If the washing granularity over the range, it is easy to block opening. In order to solve this problem, we must guarantee the feeding granularity.
1.4 Reduce over crushing during crushing operation
Over crushing will not only cause large waste of resource, influencing the economic benefits of coal enterprise, but also increase water content of pulverized coal and the system pressure of coal slurry. With the improvement of environment protection and increased cost of pulverized coal processing, minimize the pulverized coal output is the key in the whole crushing process.
1.5 Demands of energy saving and consumption reducing
At present, the production cost of crushing and grinding operation will take up more than 40% of the total cost in concentration plant, but the investment of crushing and grinding machine will take up around 60% of the total investment. The proportion of production cost and infrastructure investment for crushing operation is lower than the total investment, but you cannot ignore the operation cost for raw coal preparation system and the effect from the infrastructure investment to technical and economic index. Therefore, increasing crushing productivity and reducing power consumption have a great significance.