| 摘要 |
Coal is separated from mining refuse utilizing an autogenous non-magnetic heavy medium and one or more cyclonic separators. In the process, raw input from mine tailings is screened and mixed with heavy medium to form an aqueous slurry feedstock. The feedstock slurry flows through a primary cyclonic separator (322) which causes a coal-rich portion to exit its overflow and a refuse-rich portion to exit its underflow. The coal-rich overflow is dewatered to produce clean coal solids and a water-rich underflow slurry. The refuse-rich underflow from the primary cyclone (322) is dewatered to produce solid refuse particles and one portion of the heavy medium. Another portion of the heavy medium is obtained by the underflow from the coal-rich slurry dewatering equipment. The primary cyclone (322) has a cylindrical section (323) with an axial extent greater than its inside diameter for imparting to tangentially-admitted feedstock slurry a substantially constant acceleration followed immediately by increasing acceleration in a depending conical portion (326). A vortex finder (331) depends to about the middle of the cylindrical chamber for exhausting the coal-rich overflow slurry therefrom, and the refuse-rich underflow slurry is discharged through a bottom orifice (329). If desired, the refuse-rich underflow from a dewatered cyclone located downstream of the primary cyclone (322) can be crushed and recycled through the primary cyclone (322) to separate middlings. |
