Recovery of clean coal from the contaminated waste of Quang Ninh province - Viet Nam

The contaminated waste is a by-product generated during coal mining process. This type of products may contain more or less 20% of clean coal, thus their ash content may vary in a wide range of 60 to 80%. This waste normally is stockpiled separately at “temporary disposal dumps” as they would not be regarded as waste in the full meaning, however, it is very sensitive for the miners who attempt to process such a waste. Based on the results of the coal characteristics survey at some surface coal mines of Vietnam, the studying authors have collected a large quantity of representative samples, such as Ha Tu, Nui Beo, Tay Khe Sim, Ha Rang mines and have carried out a number of experiments using low cost and highly efficient separating equipments. These are semi-industrial movable screen jig, fluidization separator, some samples of -0.5 mm size using flotation method. Products of processing include clean coal, which has ash content obtain quality standard of Viet Nam (clean coal is consumed easily) and tailings have ash content over 80%, which can waste. The study results showed that the application of the new machines could allow significant recovery of clean coal from the contaminated waste. This may significantly contributes in reduction of environmental pollution while ensuring the production viability and economic efficiency for the miners.