Study On Shearing Evolution And Connected Mechanism Of Flocs Pore Structure In Thickened Tailings

The mining produces a large number of tailings every year,which makes the disposal difficult and harm the environment;with the concept of "lucid waters and lush mountains are invaluable assets" put forward,the disposal of solid waste such as tailings will face great challenges.Paste backfilling technology has been paid more and more attention by minings with the advantages of environmental protection and safety;however,the fine tailings thicken disposals has become the development bottleneck.Increasing the tailings concentration can not only ensure the safety of underground,but also reduce the surface subsidence;It will also provide water-saving ways for mining in arid areas.In this work,dynamic thickening test will be carried out with tailings thickening treatment as the core;with the help of CT technology,the evolution law of floc pores is explored,the mechanism of water conductivity and drainage of floc is studied.The main work and research results are as follows:(1)Semi-industrial thickening platform.The platform can simulate the actual operation of thickener,it also can adjust the rake speed and control the feed rate.It can study the settlement track of flocs and obtain the flocs morphology of the bed.(2)Visualization of pores structure.The pore structure of flocs was analyzed by CT scanning,and found that shearing can reduce the flocs porosity;the pores structure is studied with parameters,and classified pores with characteristics.(3)Mechanism of flocs thickening and dewatering.The water conductivity and distribution of flocs are studied,and found that dewatering with channel from bottom to top.Shearing can realize flocs thicken,and the remold flocs are more closely.(4)Quantitative study of pore network model.The pores structure is identified by algorithm,and the model is divided.The concept of "ball to stick ratio" is proposed to describe the water source,and found the drainage is mostly from the channel.(5)The thickener improved.Increasing the rake length and adding dilution pump,the underflow concentration can reach 60%～70%,80% water can be saved every year.