Effect of microwave-preconditioning on the grindability and floatability of copper-nickel ore

Two aspects of mineral processing are investigated in this work, namely, the effect of microwave radiation on the grindability and floatability of nickel-copper ores obtained from the Sudbury basin.; In the grindability study, prior to mechanically grinding the material, microwaves are used to selectively heat parts of the rock, causing them to fracture along grain boundaries. The results show that the largest feed size exhibits the best results in terms of grindability at an exposure time of 10 s and under a microwave power of 74% (1.41 kW). The obtained relative work index is ∼23%, and the gain in energy is ∼1.5 kWh/ton.; In the floatability study three parameters, namely, microwave exposure time, feed size, and pre-conditioning with and without the addition of collector, have been investigated. Microwave treatment of the ore has improved the flotation process quantitatively and qualitatively. The best results achieved consist of an increase in concentrate recovery of ∼47% for samples of 50 mum after 90 s, copper grade is enhanced by ∼48% for samples of 50 mum after 60 s. Nickel grade is improved by ∼16% for samples of 75 mum after 60 s. Copper recovery is enhanced by ∼68% for samples of 50 mum after 90 s, and nickel recovery is improved by ∼16% for samples of 50 mum after 90 s of microwave exposure. The addition of a collector has resulted in a maximum amount of concentrate, viz., 16%, after 30 s of exposure time, and the grade of copper and nickel have attained their maximum values after 90 s, viz., ∼17% and ∼28%, respectively. In terms of copper and nickel recoveries the best results obtained after 30 s of microwave treatment are ∼16% and ∼8%, respectively. (Abstract shortened by UMI.)...