Carbon/Char-Coal Fines & Filter Cake Utilization
The coal produced in mines, sorted and refined at the coal factories. The result is an enrichment of coal as a commodity, and the filter cake with fractions of less than 1 mm. The filter cake is typically a clay substance obtained as a result of the separation of raw coal by fractions. Larger fraction is sent to the further process of concentration and drying in kilns. The fine fraction (cake) is typically utilized as a waste.
The usual fuel for kilns coal-preparation plants is a coal is produced by factory and which is sold as a product. Coal gets into the furnace through the dispenser, feeder and burns on the grate.
Consumption of salable coal for drying in kilns could be reduced by its partial replacement by Coal Slurry (CWS) which produced from the filter cake. CWS is sprayed into the furnace above the grate though the air nozzle.
According to tests it is determined that the combustion of 1 ton CWS from filter cake saves at least 1 ton of salable coal.
Thus, combustion of coal-water slurry from cake allows coal factory to solve two problems at once:
- Reduce consumption of salable coal for technological needs, ie, reduce their own costs for the production of coal.
- Dispose of unused coal filter cake having an ash content of about 30 … 40% and humidity up to 30%.
The proposed solution could be implemented on most of majority of coal factories.
In addition to filter cake other small coal fractions could be used as a raw material for CWS.
CWS from filter cake could be effectively made in by Hydroshock Wet Milling Machibe (WMM). WMM makes a uniform (homogeneous) suspension, which is easily sprayed through a nozzle.
Example of burning of CWS from filter-cake in an drying kiln: