Refinement of the flotation reagent plan based on coal feed ash content

Abstract

The effect of frother dosage (67, 200, and 400 g/t), collector dosage (200, 600, and 1000 g/t), and frother type (Mixed aliphatic alcohol (MAA), Methyl Isobutyl Carbinol (MIBC), and pine oil) on the flotation performance of three coal samples with various ash contents of 45.1% (high ash content coal, HAC), 36.8% (moderate ash content coal, MAC), and 30.7% (low ash content coal, LAC) was studied. The optimal flotation conditions for each coal sample were quite different. For HAC, a clean coal with an ash content of 12.8% and a yield of 38% was produced under optimal conditions using MIBC as the frother dosage of 361 g/t, and a collector dosage of 200 g/t. In the case of MAC, a clean coal with an ash content of 10.2% and a yield of 46% was produced under optimal flotation conditions using MAA as the frother dosage of 148 g/t, and a collector dosage of 200 g/t. For LAC, a clean coal with an ash content of 9.87% and a yield of 57.4% was produced under optimal flotation conditions using pine oil as the frother dosage of 174 g/t, and a collector dosage of 1000 g/t. For LAC feed coal, in comparison with HAC feed coal, a lower frother at dosage, higher collector dosage, and pine oil frother instead of MIBC must be used. The optimal conditions for HAC flotation were validated in a coal washing plant. After conducting the necessary modifications to the flotation reagent scheme, yield, combustive material recovery (CMR) and separation efficiency (SE) of the plant increased by 5.9%, 11%, and 7.5%, respectively which results in more clean coal production of about 14160 t/y.