With economy development, increasing volume of mineral and energy resources are required. Coal mining industry is also highly developed. New coal preparation techniques are applied in coal mining process. Fine coal with particle size about 12 mm was traditionally deslimed at about 1 mm wet screening and processed via dense-medium cyclones.
The minus 1 mm was then either disposed of or upgraded with spirals. The thermal coal specifications require relatively low calorific value and moistures. One cost effective way is to screen the dry, raw fines out of the plant feed prior to processing.
By screening out the raw fines and only processing the coarse coal, a simpler and smaller plant is required resulting in a significant cost reduction.
Coal Screening Machine Application
Screening of fine coal at small apertures is possible when the moisture content of the coal is low- typically lower that about 5% surface moisture. When the moisture content of the feed is higher than this, screening becomes very difficult due to the finer fractions adhering to the larger particles.
Coal screening machine handles the fine material well and no blinding or clogging of the screen cloths was observed. This ensures that adequate screening area is always available but, despite the vigorous action provided by the screen surfaces, adhering fines still cannot be dislodged to the extent where very damp coal can be effectively screened.