Effect of Tannin on Compound Collector Adsorption and Stibnite and Arsenopyrite Flotation from Complex Ore

Technological Application of Tannin-Based Extracts

“…Additionally, this type of compound allows replacing highly toxic compounds used as flotation agents by a material of plant origin. Thus, for decades, tannins have been used as depressants in flotation processes and applied to improve the efficiency of extraction or concentration of gold from complex ores, jamenosite, strontium, rare earth oxides, scheelite, fluorite, and sulphides (copper-lead-zinc-nickel ores) [82][83][84]. Many studies have been performed to evaluate the capacity of different types of tannins, as well as to optimize the parameters that maximize the extraction of target metals.…”

“…Tannins are capable of carrying out selective adsorption on the surface of some sulphide minerals such as stibnite, arsenopyrite, and chalcopyrite, as well as exerting a selective effect on the adsorption of a sulfhydryl collector which makes them interesting compounds for effective recovery of minerals such as those forming complex gold ores [82][83][84]. Antimony and gold are two metals of recognized commercial importance.…”

“…Thus, tannins are capable of suppressing arsenopyrite and provide active flotation of antimony sulphide; but do not form a dense covering on stibin and do not desorb copper dithiocarbamate from the surface of the activated mineral. However, by adjusting the consumption rate of phytogenous, the modifier-tannin controlling flotation activity of stibnite and arsenopyrite is possible [83]. Nowadays, another important source of gold is recovered from e-wastes (wastes from electric or electronic devices) which have been considered as secondary gold ore.…”

Oxidative Depression of Arsenopyrite by Using Calcium Hypochlorite and Sodium Humate

“…Sulfide-ore-bulk flotation followed by selective copper flotation with the addition of arsenic sulfide depressants can also separate copper and arsenic ores via conventional flotation [6]. Flotation of arsenic separation from non-arsenic copper minerals routinely uses the mixture of sodium cyanide, lime, sodium hydrosulfide, sodium sulfite, and magnesium-ammonium [6][7][8][9]. However, environmental friendliness and technical and cost effectiveness are some factors that limit the industrial applications of most depressants.…”

“…However, its toxicity limits its application [10]. Lime can also be used as a depressant but usually requires large dosages [8]. Addition of a great amount of lime not only decreases chalcopyrite flotation rate and recovery but also increases plant operation costs [11].…”