Abstract: With an eye to the breakdown of NZ-12 thickener in Yunnan Lancang Lead Mine,flash solid-liquid separation technology(combined use of cyclone and concentrator)is adopted while utilizing fully the original equipment.One stage solid-liquid separation is changed into two stage solid-solid,solid-liquid separation.The solid load inside the thickener is reduced by 50% and the grain size is less than 40μm.Use of high molecule plastic reduces the rake diameter by 2.56m and the operating torque of thickener by 40%.The ordinary thickener is transformed into high efficiency thickener successfully without adding operation cost.The practice of more than 3 years proves that the plan is advanced,reliable,stable and effective.