A wind-tunnel study of the dust emissions from the continuous dumping of coal

Abstract Dumping is one of the major activities in the storage and handling of coal. Because of the absence of reliable emission factors for the Dutch situation, measurements both in the field and in the wind-tunnel have been carried out to determine the effects of several variables on fugitive coal-dust emissions. The effects of moisture content and wind velocity have been studied in this wind-tunnel study. The wind-tunnel study shows that emissions from the continuous dumping of coal can be divided into an impaction and a windsift part. The impaction part is important only for low-wind velocities and dry coal, while, in general, the windsift part will be dominant in practice. Windsift emissions are dependent on the variables wind velocity and moisture content. They are directly proportional to the fourth power of the wind velocity and roughly inversely proportional to the fourth power of the moisture content. This means that the influence of these variables on fugitive dust emissions is much higher than suggested by most of the existing literature. So, wind velocity and moisture content are extremely useful variables in policy instruments to reduce the environmental impact of coal dumping.