Kinetics of Chalcopyrite Leaching by Hydrogen Peroxide in Sulfuric Acid

Abstract

In ores, chalcopyrite is usually associated with other sulfide minerals, such as sphalerite, galena, and pyrite, in a dispersed form, with complex mineralogical structures. Concentrates obtained by flotation of such ores are unsuitable for pyrometallurgical processing owing to their poor quality and low metal recovery. This paper presents the leaching of chalcopyrite concentrate from the location “Rudnik, Serbia”. The samples from the flotation plant were treated with hydrogen peroxide in sulfuric acid. The influences of temperature, particle size, stirring speed, as well as the concentrations of hydrogen peroxide and sulfuric acid were followed and discussed. Hence, the main objective was to optimize the relevant conditions and to determine the reaction kinetics. It was remarked that the increase in temperature, hydrogen peroxide content, and sulfuric acid concentration, as well as the decrease in particle size and stirring speed, contribute to the dissolution of chalcopyrite. The dissolution kinetics follow a model controlled by diffusion, and the lixiviant diffusion controls the rate of reaction through the sulfur layer. Finally, the main characterization methods used to corroborate the obtained results were X-ray diffraction (XRD) as well as qualitative and quantitative light microscopy of the chalcopyrite concentrate samples and the leach residue.

Effect of Pre-Treatment with Sodium Chloride/Sulfuric Acid on the Bornite Concentrate Leaching in Chloride Medium

“…In research on the leaching of bornite done by Pesic and Olson [20], the dissolution of copper from bornite reached 26 to 28% during the first hour of the process in the presence of ferric ion, which are values greater than those obtained in this study in a chloride medium and without the initial presence of ferric ion, as shown in Figure 1. Furthermore, in the studied system, this function can be performed by the Cu 2+ /Cu + redox pair, which was formed from dissolved soluble copper [35], but it is restricted because the leaching systems require the addition of oxygen for the oxidation of the cuprous products [7,36], according to Reactions (4) and (5).…”

“…Traditionally, froth flotation and pyrometallurgical processes have been used for the treatment of copper concentrates from high-grade copper ores [2,3]. However, the constant decrease in ore grade, presence of toxic elements, and stricter environmental legislations make the hydrometallurgical option way more attractive [4,5]. In the last years, research and development have intensified in the search for hydrometallurgical alternatives to the processing of copper concentrates [6][7][8][9][10].…”

Atmospheric leaching of copper from oxide-sulfide ore using sulfuric acid

“…Značajan deo bakra u zemljinoj kori nalazi se u obliku halkopirita. On je u polimetaličnim rudama često srastao i pojavljuje se sa drugim sulfidnim mineralima, poput pirita, galenita i sfalerita i mineralima jalovine [1,2]. Pored toga, opšta karakteristika većine eksploatisanih sulfidnih ležišta ogleda se u minerološkoj segregaciji, gde se u površinskim slojevima ležišta koncentriše oksidna ruda, u srednjim slojevima oksidno-sulfidna i konačno u dubljim slojevima ležišta sulfidna ruda.…”

Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters

“…Froth flotation produces copper concentrate with some trace elements that are considered impurities, principally arsenic and antimony, and minor elements such as Cd, Hg, Pb, Bi, Se, and Te. The most common mineralogical species associated with toxic impurities present in copper concentrates are enargite (Cu 3 AsS 4 ), arsenopyrite (FeAsS), rejalgar (AsS), tennantite (Cu 12 As 4 S 13 ), tetrahedrite (Cu 12 Sb 14 S 13 ), and famatinite (Cu 3 SbS 4 ) [1][2][3][4][5][6].…”