The Study Of Mercury Occurrence In Coal And Migration Regularity During Coal Preparation

Control of heavy metal pollution of coal combustion is one of the most important environmental protection subject in 21st Century, especially mercury that is easy to volatilize and very hard to control during coal combustion. So Coal combustion is the most main man-made source of mercury in the atmosphere. Coal preparation is an effective method to decrease mercury pollution form Coal Combustion, at present, coal washing techniques is only considered deliming and desulphurization and is still a blank to mercury. Therefore, on the basis of accurate determination of mercury in coal, mercury and sulphur distribution of coal in different size and density components are studied by floating-sinking test. Combined with sequential extraction experiments, modes of occurrence of mercury in coal is also studied; According to the result of float-sink test, effect of deliming, desulphurization and mercury control are predicted using distribution curve model; Prediction results are verified by testing ash sulphur and mercury content in coal preparation products in different process stage and the migration behavior and potential washability of ash, sulphur and mercury in the process of coal preparation is studied. And then migration mechanism and influence factors are discussed according to mode of occurrence of sulphur and mercury in coal. It provides evidence for the simultaneous realization of deliming, desulphurization and mercury control...