Chinese
Dry stacking of tailings generally adopts concentration technologies such as filtration, press filtration, and sedimentation to dewater tailings and reduce the moisture content to around 20%. In recent years, the development of dry stack tailings concentration processes has mainly been reflected in the following aspects:
(1) The combined process of hydrocyclone, thickener, dewatering screen, and filter press (or filtration equipment) has become increasingly mature. This process is currently the mainstream method for dry stack tailings concentration. Tailings from the beneficiation plant are first fed into a hydrocyclone, where the underflow is sent to a dewatering screen to achieve coarse particle dewatering. The hydrocyclone overflow and the undersize from the dewatering screen are combined and sent to a thickener. The thickener underflow is then fed into a filter press (or filter machine) to achieve fine particle dewatering. For example, in the dry stacking of certain copper tailings, a process involving hydrocyclones, dewatering screens, thickeners, and filter presses is used to classify coarse and fine particles separately and then perform concentration and dewatering respectively.
(2) A combined process using hydrocyclones, horizontal belt vacuum filters, and filter presses. In this process, tailings are first classified using hydrocyclones. The high-concentration coarse particle fraction is filtered using a horizontal belt vacuum filter, while the low-concentration fine particle fraction is concentrated in a thickener and then filtered using a fully automatic vertical filter press. The resulting filter cake is discharged as dry solids, and the filtrate is recycled for reuse.
(3) A combined process using multi-stage variable cone hydrocyclones, high-frequency fine screens, and rake-free high-efficiency thickeners. This process utilizes a new type of multi-stage variable cone hydrocyclone to classify tailings. Coarse particles are dewatered by high-frequency screens for dry stacking, while fine and ultra-fine particles are concentrated and dewatered through rake-free high-efficiency thickeners.
In summary, for dry stack tailings treatment, the combined process of thickeners, hydrocyclones, dewatering screens, and filter presses (or filtration equipment) has become a mature and widely adopted technology in beneficiation plants. It offers broad prospects for further application. The development and application of new concentration and filtration equipment will also become a key direction for future technological advancement.
