Abstract:

Currently at Maokhe coal mine, there is a great amount of stockpiled coal middlings which was produced in the air shaking table cleaning process. This amount is increasingly accumulated and occupies a large area of the washing plant. As result of this coal, the plant production efficiency is reduced and the risk of enviromental pollution increased. This article presents some selected charateristics of this type of coal that include: particle size distribution; density distribution, ash distribution as well its washability. Based on the result of the sample analysis, the authors carried out experiments, in which the size fraction of 3 – 22 mm was cleaned by a laboratory moving sieve jig; the size fraction of 0,5 – 3 mm was cleaned by a fluidised bed separator while the fine coal (- 0,5 mm) was processed by flotation machine. From the study result, two upgrading options are proposed as the follows: the first is to process only size fraction +0.5 mm, by this option a clean coal yield of 62,91 % with the ash content equivalent to the standard fine coal 5MK and a tailings of over 77 % ash content were obtained. the second option is to process full size range and by this options, a clean product yield 54,39% with the ash content equivalent to the standard fine coal 4b MK and the tailings of 78% ash content were obtained.