Effect of microwave system location on floatability of chalcopyrite and pyrite in a copper ore processing circuit

Abstract

The present work aims at investigating the effect of microwave local positions (i.e. before crushing (BC), after crushing (AC) and after milling (AM)) on microwave-assisted flotation of chalcopyrite and pyrite in a porphyry copper complex deposit. Individual given samples for each state were pre-treated with a variable power microwave at a power level of 90 to 900W for 15, 30, and 60s. Furthermore, froth floatation experiments were carried out using a laboratory mechanical Denver flotation cell on both microwave-treated and untreated samples. Particle surface properties were characterized by a scanning electron microscopy (SEM) and an energy-dispersive X-ray spectroscopy (EDX) analysis. The results showed that the chalcopyrite and pyrite floatabilities increased monotonically by rising the exposure time and power level for the uncrushed preconditioned samples (BC) due to the enhancement of mineral liberation degrees together with the formation of sulphide species and polysulphides on the mineral surfaces. However, flotation results of treated samples for the crushed one (AC) revealed an optimum range. Formation of intensive oxide layers on the mineral surfaces of milled samples (AM) led to a substantial reduction in their recoveries by increasing the microwave's power level and the sample's exposure time. The results obtained from mineral's floatabilities in recleaner stage showed that the microwave-assisted sample at 900W for 30s at BC state favourably provided 5% higher S.E.'s than that of the untreated sample. Finally, it was concluded that the microwave pretreatment of samples induced the best floatability responses if it located before the crusher.

Parametric Optimization in Rougher Flotation Performance of a Sulfidized Mixed Copper Ore

“…Then, 1100 g representative samples were ground by a laboratory Bond ball mill (12 × 5 in, Denver, England) at an optimal time of 22 min [5] with a solid percentage of 70% w/w to reach 80% passing ∼80 µm. This particle range is identified as the most favorable size for copper flotation in several works conducted by the authors [49][50][51][52]. The sieve analysis of mill product (flotation feed) is presented in Table 3.…”

The Microwave Irradiation Effect on the Floatability of Mixed Sulphide/Oxide Copper Ores

“…As mentioned, Sungun copper flotation feed consists of copper sulphide minerals, gangue minerals such as pyrite and, to a lesser extent, copper oxide minerals. The floatability of pyrite and chalcopyrite, as the major gangue mineral and the major copper-bearing mineral in Sungun copper ore, respectively, decreases with an increase in time and radiation power (Gholami et al, 2020). Therefore, a decrease in the amount of copper grade as well as the recovery of flotation under the radiation of microwaves can be attributed to the decrease in the floatability of these minerals.…”

“…For flotation experiments, after preparing the pulp and resting for a conditioning time of 3 minutes, the pH was adjusted and the collector and frother were added to the cell. The condi- changes their recovery and grade during the flotation process by altering their surface properties (Gholami et al, 2020). Figure 4 shows the diagrams of grade -flotation time of copper sulphides under the power of 90, 360 and 600 watts microwave irradiation and the same irradiation time.…”

Fine, coarse and fine-coarse particle flotation in mineral processing with a particular focus on the technological assessments

“…Although these concepts are well established, only a few technological developments have been appeared in mineral processing industries over the last decades. Microwave technology [5][6], high pressure grinding rolls (HPGR), and pneumatic type flotation cells are the major illustrations in this regard. The most recent industrial examples might be the commercialized rapid microwave and Nova Cell TM .…”