Passivation of heavy metals in tailings dam of metal mine byhigh pressure rotary jet process

In order to passivate heavy metals in the tailing pond of metal mine, the stabilization of Cr、Zn、Cd、Pb in tailing sand was studied by using three passivating agent, namely, thomsonite, Bentonite and attapulgite, and high pressure rotary jet technique was used to passivate heavy metals in the tailing sand by injecting passivating agent into the tailing dam.Heavy metals contents in the tailing sand and in the leaching solution, before and after the injecting process, have been analyzed to evaluate the ability of the attapulgite clay in immobilizing the active form of heavy metals.Changing the parameters of high pressure rotary jet grouting, such as injection pressure, hoisting speed and aperture interval, the immobilizing effect have been analyzed completely and a set of relatively perfect experimental parameters have been gotten.The results showed that putting and mixing the attapulgite clay filtering less than 74 μm seize into tailing land by the clay-land mixture ratio of 1∶10, the average decrease rates of the active form of Cr, Zn, Cd, Pb in land were 30.5%, 87.8%, 82.9% and 42.4% respectively.And the simulation experiment showed that when the sampling sites were in the area of the spinning jetting of the pile, liquid-solid rate in slurry was 1.12, pumping pressure was 23 MPa, the flow of slurry was 90 L/min, hoisting speed was 14 cm/min, rotate speed was 14 r/min, the rate of consumable material was 75 kg/m, the effectiveness of the passivating agent in immobilizing heavy metals active forms was the best in the experiments.