Abstarct: Water plays a major role in the mineral processing industries. Severe shortage of water has increased its value in processing plants, thus water recovery as much as possible in processing plants needs more attention. Gol Gohar iron Ore Mine is the biggest iron Ore Mine in Iran, this complex is located in a water scarce region and recent droughts and development projects of the Complex highlighted the need to plan for water recovery. According to this plan by using a high rate thickener and filter press final solid content reaches 90% which prevents wasting a lot of water. In addition to prevent wasting water, the plan by eliminating the cost of construction of tailings dam and reducing water transmission costs is economically justified. Many experiments with batch and semi-continuous methods have done to design high rate thickener of water recovery plant. The duty of the thickener is preventing fluctuations of tailing solid content and bringing this content to an optimized level for filtration operation. In order to do this, a thickener which is able to bring this content to 58% is required. baxsed on batch experiments the thickener diameter was measured 36 m and baxsed on semi-continuous experiments the thickener was designed with 28 m of diameter and 3 m of height. The optimum work condition for this thickener is with 6% input solid content, F140 flocculant and flocculant concentrations equal with 30 gram per ton