Agglomeration-Flotation of Finely Ground Chalcopyrite and Quartz: Effects of Agitation Strength during Agglomeration Using Emulsified Oil on Chalcopyrite

Abstract

In flotation, the size of mineral particles is one of the most important parameters: when the size becomes fine, collision efficiency of the particles and air bubbles becomes low, causing low flotation recovery. To improve the collision efficiency and flotation kinetics, agglomeration using the emulsified oil of finely ground chalcopyrite (D50 = 3.5 μm) was carried out before flotation. In this study, the effects of agitation strength during agglomeration, kerosene dosage and potassium amyl xanthate (KAX) dosage on the flotation were investigated. Agglomeration using emulsified oil improved Cu recovery because the median diameter of agglomerate increased. With increasing agitation strength, KAX and kerosene dosages, Cu recovery was further increased. Agglomeration-flotation of a mixture containing chalcopyrite and quartz with 1:1 ratio (w/w, weight by weight) showed that Si recovery in froth was low and did not change with varying conditions (agitation strength, KAX and kerosene dosages); however, Cu recovery was significantly improved with increasing agitation strength, KAX and kerosene dosages, and thus the separation efficiency was improved.

Agglomeration–Flotation of Finely Ground Chalcopyrite Using Emulsified Oil Stabilized by Emulsifiers: Implications for Porphyry Copper Ore Flotation

“…The smaller oil droplet generated in the presence of emulsifiers could be attributed to the reduction in interfacial tension of oil-water [32]. In the previous study of the authors [4], emulsified oil was added to the agglomeration vessel immediately because emulsified oil without surfactant was unstable. In a commercial plant, stability of emulsified oil is important to maintain the small size of oil droplets for oil agglomeration.…”

“…Trahar [15], for example, studied chalcopyrite-quartz flotation and reported that the recovery of chalcopyrite was lower when the median particle size decreased from 20 to 3 µm. In the previous work of the authors, agglomeration-flotation using emulsified oil instead of directly adding oil during the agglomeration step was conducted using finely ground chalcopyrite [4]. The results showed that the stability of emulsified oil was relatively short, so strong agitation strength is required to disperse oil droplets into water, maintain the small size of oil droplets, and facilitate particle agglomeration [4].…”

“…For example, the largest open pit porphyry copper mine in the world-the Escondida mine in Chile-processes a porphyry copper deposit containing 0.25 g/t Au and 0.0062 wt% Mo [2]. The conventional technique used to recover valuable minerals 2 of 10 from porphyry copper ores is flotation, a technique whereby fine particles of Cu-bearing minerals like chalcopyrite (CuFeS 2 ) are separated from gangue minerals and collected by bubbles after surface modifications using emulsifiers called collectors [3,4]. Flotation, including its concept of using bubbles to induce separation of materials with different surface wettability properties, is a popular and widely used technique not only in the mineral processing and coal cleaning/washing industries but also in electronic waste and plastic recycling industries [5][6][7][8][9][10][11].…”

“…In the previous work of the authors, agglomeration-flotation using emulsified oil instead of directly adding oil during the agglomeration step was conducted using finely ground chalcopyrite [4]. The results showed that the stability of emulsified oil was relatively short, so strong agitation strength is required to disperse oil droplets into water, maintain the small size of oil droplets, and facilitate particle agglomeration [4]. This strong agitation during agglomeration requires high energy, which make the process costly and problematic when integrated into actual flotation circuits.…”

A Population Balance Model for Shear-Induced Polymer-Bridging Flocculation of Total Tailings

“…Many researchers have conducted related experiments and simulation studies to investigate the effect of flocculation on solid-liquid separation of tailings slurry. With respect to the experimental conditions, we comment that suspension concentration, flocculant dosage, shear rate, and other flocculation conditions influence the settling velocity and underflow concentration macroscopically [6,[12][13][14][15][16]. It was found that Rheomax DR 1050 has a better flocculation performance than conventional acrylamide/acrylate copolymer flocculant when the suspension concentration is high [6].…”