DESIGN OF METALLURGICAL COAL PREPARATION FLOWSHEET FOR THE MAXIMUM
PLANT EFFICIENCY
Coal remains an important energy source and is crucial for the steel industry, although high quality coal
reserves are depleting worldwide. Modern highly mechanized extraction technologies and their economical
optimization lead to an increase in the average ash content of the coals and make it more problematic to
control the product quality. The competitive market for coal makes more attractive mechanical cleaning of
the coals with low washability characteristics raising, at the same time, numerous processing problems.
This paper describe solutions for process optimization and efficiency improvement applied in the course of
project development of the coal preparation plant Uvalnaya located in Kuznetsk coal basin, Siberia, Russia.
Many complications were faced, including soft clays in host rocks, excessive middlings yield in coarse size
class, stringent concentrate quality conditions, the smallest possible size of plant, and extreme weather
conditions with temperature going down beyond -40°C in winter.
Modern computer technologies based on the mathematical models of preparation processes allowed
exploring of various options for process layout and determining of the optimal process parameters under
present and future market requirements. Liberation study performed on coarse middlings after their
crushing showed a way for a possible increase in clean coal recovery. Therefore, final flowsheet includes
operations of middlings crushing and reprocessing.
Results of this work show the existence of feasible routes for treatment of coals that are deemed as “hardto-beneficiate”. Even though characteristics of coal differ from one deposit to another, the conclusions
made can be considered as a general trend for plant design under worsening quality of reserves and harsh
climate conditions.
KEYWORDS
Coal, washability, middlings, crushing, flowsheet, simulation, plant design.