Production of paste from fine tailings streams in a laboratory scale column thickener

Abstract

The final disposal of tailings in the form of paste is a technological alternative. The objective of the present study is to obtain knowledge and compare different operational conditions that are favorable to the production of paste with the fine tailings generated after final desliming stage, obtained from the processing of metallic and non-metallic ores. The sample tailings, despite having a specific weight and similar granulometry, presented different behaviors related to the formation of paste. The minerals calcite and dolomite were predominant in the phosphate tailings while in the manganese tailings, there were pyrolusite and kaolinite. The used column thickener with the best operational conditions found to obtain a maximum concentration of solids after 3 hours of continuous thickening: 55% (manganese tailing) and 70% (phosphate tailing), with values of yield stress around 100 Pa and 300 Pa respectively. This indicates that the pumping conditions are not the same. According to the slump and flume tests, it was possible to preliminary estimate the reduction of the disposal area and the recovery of process water considering the case of a final disposal paste.