Integrated Disposal of Paste Backfill and Surface High-Concentration Tailings Stacking at Chambishi Copper Mine

摘要

Inspired by the success of cemented paste backfill in the west orebody of Chambishi Copper Mine,integrated disposal of paste backfill and surface high-concentration tailings stacking was applied inthe southeast orebody. This paper presents the integrated disposal system, including two deep conethickeners, double-shaft horizontal mixer, two plunger pumps for underground backfill and threediaphragm pumps for surface stacking. The challenges of the integrated disposal system were deepbackfilling (0.98 km) and long-distance discharging (15 km), so a combination of gravity flow andpumping was used in paste backfill and three diaphragm pumps with a preset pressure of 7 MPawere applied for surface stacking. The annual ore production in the southeast orebody is 3.3 Mt,which is 3.3 times larger than that of the west orebody. Therefore, the capacity of the integrateddisposal system also needs to be expanded. The capacity of the paste backfill system and surfacestacking system were 160 m3/h with paste concentration of 75 wt.% and 265 m3/h with slurryconcentration of 55 wt.%, respectively. In the first phase, the cement to tailings ratios for primary andsecond stopes are 1/8 and 1/24 respectively. To meet the backfill strength and reduce the cost, wasterock will be added in paste backfill in the second phase, the waste rock to tailings ratio is 1/3, thecement to tailings and waste rock ratio for primary stopes are 1:12, and 1:30 for secondary stopes. Asa result, the UCS after 28 days for primary and second stopes were 1.2 MPa and 0.5 MPa, respectively.