Beneficiation of Talc-Magnesite Ore with Cu-Co Mineralization

Abstract

Magnesite ore with a low chalcopyrite – cobaltite mineralization was subjected to a series of separations designed to evaluate thepossible concentration of the two accessory minerals. Although the Cu-Co grade in the ore (> 0.01% Co, > 0.1% Cu) is significantlylower than the typical economic grades, content of the main valuable mineral for which the ore is mined and processed incombination with a listing of cobalt as a critical raw material, coupled with their higher price might compensate for the additionalbeneficiation stages. The ore was first crushed and subsequently classified to -100 μm and +100 -400 μm size fractions. The finefraction was upgraded by froth flotation processing in laboratory froth flotation cell. The coarser fraction was processed in severalseparation stages including gravity separation on shaking table, magnetic separation and corona electrostatic separation. The sameprocedure was also repeated with a higher-grade sample as a verification of the procedures. Preliminary results suggest that theaccessory minerals can be separated from the talc-magnesite ore and individual mineral concentrates with about 19% Co and 28%Cu were prepared. However, further work must be done to achieve desirable recoveries for the processing to be economically viable.

The Differences in Evaluation of Flotation Kinetics of Talc Ore Using Statistical Analysis and Response Surface Methodology

“…It has been previously shown that the presence of very fine particles has a negative effect on the concentrate grade due to the entrainment effect [4,30,31] and possibly also because of the formation of slime mineral coatings on surfaces of talc particles [22,23]. To minimize the influence of the entrainment effect on the results of the flotation tests, two approaches were used as follows: rather extensive use of screening or sieving during the comminution stage and froth washing during flotation tests [21]. Removal of fine particles prior to the next comminution stage is a common practice used to prevent overgrinding of the ore. We were thus able to achieve d80 = 150 µm with only about 20% of particles below 25 µm, which are most likely to be recovered by the entrainment effect [30].…”

“…From the measured weight of the four obtained products, first individual and then cumulative yields (γ) were calculated. Results of the grade analyses and calculated yields were then used to calculate the cumulative product grade (c) in terms of talc content [21]. Cumulative yields of the froth product, the content of talc in the cumulative froth product at the three different flotation times (τ), and content of talc in the feed (α) were then used to calculate the recovery of talc (R t using Equation (1)) and gangue minerals (R g using Equation ( 2)) to the froth product (talc concentrate) as follows:…”

“…In our recent paper [21], we investigated the effect of sodium hexametaphosphate (SHMP) alone and in the presence of soluble starch (SS) on the flotation kinetics of talc ore and compared it to a native flotation using only methyl isobutyl carbinol (MIBC) frother. Earlier studies found that SHMP acts as a selective depressant/dispersant of carbonates [6,22] and silicates [23], which are mineral groups commonly associated with talc, and described some phenomena behind it.…”