Present Status and Feasibility Analysis on Middlings Rewashed in China

In order to study the feasibility of middlings rewashed from Xingtai Mine Coal Preparation Plant, the paper summarized and analyzed the present two mi ddlings rewashed plans, including the particle size of middlings were crushed to 1 (3 or 6) mm and the particle size of middlings were crushed and grinded to 0.5 mm.， According to the embedded state of combustible and non-combustible in coal, it could determine the rewashed plan. On the basis of analysis, screening test and sedim entation test of middlings and particle size 3 ~ 0. 5 mm materials of crushed middlings were carried out. The results showed that the present dense medium separation system of Xingtai Mine Coal Preparation had good separation effects, the amount of gangue in middlings was low, but some clean coal could be achieved when middlin gs were crushed and dissociated. The initial prediction showed that 0.9 t clean coal theoretically could be achieved from crushed and rewashed middlings to single han dling capacity system per hour and more than 4 500 t clean coal could be obtained per year.