Initial commissioning parameters research of full-tailings backfill system in metal mine: From laboratory tests to industrial operation

Abstract

As an extension of the previous investigation which has studied the impact of high-level circulation and floc residence time on underflow concentration and rake torque during initial commissioning of deep cone thickener (DCT), this work carried out the commissioning of the full-tailings backfill system, innovatively translated existing research results in the field of backfill into practical commissioning operation, bridging the gap between theory and practice. The commissioning included three stages: underflow slurry preparation in DCT, backfill slurry (BFS) preparation in mixer, and pipeline transportation. Each stage of commissioning requires support from laboratory tests. During the DCT commissioning stage, static flocculation, dynamic flocculation, and industrial deep cone flocculation tests were conducted to determine key parameters, including the optimal flocculant unit consumption, tailing slurry concentration, tailing feeding flow rate, mud layer height in DCT, floc residence time, and rake torque. In the mixing and pipeline transportation stage, slump, L-pipe, water bleeding, and strength tests were performed to establish the appropriate cement-to-sand ratios, concentration, and flow rate for BFS. The laboratory test methods and parameter results provided a systematic and phased approach to backfill system commissioning, holding significant reference value for the commissioning of backfill system in similar projects. Additionally, relationship models were developed to correlate the flocculant dosage in feed-well with tailing feeding flow rate, the amount of cementitious material added in mixer, and the amount of dilution water introduced during mixing. The application of these models ensures precise materials addition during commissioning, providing a theoretical foundation for the safety and efficiency of the backfill process. Overall, based on the laboratory test results and material addition models, the backfill system has been successfully commissioned, which is of significant importance for understanding the entire process of tailings treatment and backfill from an industrial perspective.