The Effect of Solids Concentration, Flocculant Dosage and Particle Size on Dewatering Behavior of Tailings Sample at Shahrebabk Copper Complex

In mineral industries, most of the processes are carried out in an aqueous environment. With the purpose of reducing costs and environmental impacts, the water content of tailing stream should be recovered. Thickening is the most widespread method of water recycling process in mineral industries. In this work, the effect of solids concentration, flocculant dosage and particle size on settling flux and compressibility of copper processing tailings were investigated. Samples were collected from tailings of Shahrebabak copper complex and laboratory tests were conducted. In laboratory scale, settling flux and final height of suspension were examined using batch settling tests. In addition, thickener underflow solids concentration was considered as an indicator of the effect of variables in full scale. Results indicated that not only settling flux but also compressibility of the suspension was improved by reducing suspension solids concentration. Furthermore, it was found that increasing flocculant dosage from 15 to 45 g/t led to an increase in settling flux about 7 times. Moreover, both settling flux and compressibility were reduced with fine particles. Industrial scale studies showed that, increasing -75 μm fraction in thickener feed from 47 to 59 % led to a decrease in underflow solids concentration from 63 to 55 %.