A comparison and selection study on comminution process schemes was conducted for a super-large low-grade porphyry copper-molybdenum mine in Inner Mongolia (with reserves of 950 million t, a design scale of 70 000 t/d, a Cu grade of 0.165%, and a Mo grade of 0.032%). The ore is moderately hard to hard and contains easily sliming minerals such as chlorite. Based on a systematic review of the application status of three types of comminution processes, including conventional comminution, semi-autogenous grinding (SAG), and high-pressure grinding rolls (HPGR), four schemes were proposed: the semi-autogenous grinding+ball mill+pebble crushing (SABC) process, 50 mm feed high-pressure grinding roll dry process, 30 mm feed high-pressure grinding roll dry process, and high-pressure grinding roll wet process. A technical and economic comparison was conducted from the aspects of equipment configuration, construction investment, energy consumption, operating costs, and total lifecycle costs. The results show that the SABC process has the lowest construction investment, which is 17.89% lower than that of the high-pressure grinding roll wet process, but has the highest production cost per ton of ore (23.55 yuan/t); the high-pressure grinding roll wet process has the lowest production cost per ton of ore (20.07 yuan/t), which is 17.34% lower than that of the SABC process. The high-pressure grinding roll wet process has the lowest present value of the total lifecycle cost, indicating its optimal long-term economic performance. Comprehensively considering the ore characteristics, equipment maturity, and total lifecycle economic performance, the high-pressure grinding roll comminution wet process of "cone medium crushing, closed-circuit screening, high-pressure grinding roll ultra-fine crushing, wet closed-circuit screening, and one-stage closed-circuit grinding" is recommended, to provide a reference for the selection of comminution processes for similar super-large low-grade copper-molybdenum mines.

Copper-molybdenum mine  /  Comminution process  /  Semi-autogenous grinding process  /  High-pressure grinding roll process  /  Total lifecycle