Abstract: For improving the efficiency in haulage of the slime dredged out from underground mine water sump and avoiding secondary environmental pollution, it is proposed to carry out predewatering of the slime before it is loaded into rail wagons. Based on results of sieve analysis of the slime excavated from the water sump and comparative analysis of various dewatering equipment available, the plate-and-frame filter press is selected for use. Practice shows that the dewatered product has a high purity and no flowability with a moisture content of less than 30%, which can be directly loaded into wagon or rubber-tired car or main belt conveyor via scraper conveyor, making it possible to effect high-efficiency dewatering and conveyance of the coal slime in different states.