A Novel Procedure for Performance Assessment of Paste Thickeners

High stability and low settling rate of phosphate fines in water suspensions encountered the dry area-located mines with serious environmental and technical challenges. The best suggestion for these mines is paste thickener installation for dewatering. In this research, the novel procedure has been proposed for evaluating the potential of paste thickeners in dewatering mining tailings. The case study is Esfordi phosphate complex (Iran). Initially, the selection criteria of a proper flocculant (environmental effects, price, particle settling rate, turbidity of overflow water, and underflow water content) were evaluated for current consuming flocculant (A-27) and 12 other ionic and nonionic flocculants. Then, flocculation performance was ranked based on the type and concentration, applying multiple criteria decision-making (MCDM) techniques of ORESTE, MAPPAC, and ELECTRE. Subsequently, the pilot-scale tests were performed for the selected flocculants and the operational conditions were evaluated for the maximum underflow solid content of 70 wt.%. The results of the present research showed that installation and application of this type of thickener could be effective for the case study.