Johnson dewatering screen is an important component of slime washing in coal preparation plant. It is mainly used for dewatering, desliming and demineralization of slime, so as to improve the quality of clean coal and improve the economic benefits of customers.
- improve the quality of coal and reduce the emission of coal-fired pollutants
Coal washing can remove 50% ~ 80% ash, 30% ~ 40% total sulfur (or 60% ~ 80% inorganic sulfur) from coal, burning washing coal can effectively reduce the emission of smoke, SO2 and NOx. Washing 100 million tons of power coal can generally reduce the emission of 600000-700000 tons of SO2 and remove 16 MT of gangue.
- Improve coal utilization efficiency and save energy
The improvement of coal quality will significantly improve coal utilization efficiency.
Some studies show that the ash content of coking coal is reduced by 1%, the coke consumption of iron making is reduced by 2.66%, and the utilization coefficient of blast furnace is increased by 3.99%.
20% coal can be saved by washing anthracite in ammonia production.
For every 1% increase in coal ash used for power generation, the calorific value decreases by 200-360j / g, and the standard coal consumption per kilowatt hour increases by 2-5g.
The thermal efficiency of industrial boilers and kilns can be increased by 3% ~ 8%.
- Optimize product structure and improve product competitiveness.
The development of coal washing is conducive to the transformation of coal products from single structure, low quality to multi varieties and high quality, and the realization of product integration.
There are many users of coal consumption, and the requirements for coal quality and variety are constantly improving. In some cities, the sulfur content of coal is required to be less than 0.5% and the ash content is required to be less than 10%. Without the development of coal preparation, the market requirements cannot be met.
- Reduce capacity waste
How far is the coal producing area from the economically developed area with more coal? The coal transportation volume is large and the transportation distance is long. The average transportation distance of coal is about 600 km, after coal washing, a large number of impurities can be removed. For every 100MT of raw coal washed, the transportation capacity can be saved by 9600mt / km.