Development of copper recovery process from flotation tailings by a combined method of high‒pressure leaching‒solvent extraction

Abstract

Sulfide copper mineral, typically Chalcopyrite (CuFeS), is one of the most common minerals for producing metallic copper via the pyrometallurgical process. Generally, flotation tailings are produced as a byproduct of flotation and still consist of un‒recovered copper. In addition, it is expected that more tailings will be produced in the coming years due to the increased exploration of low‒grade copper ores. Therefore, this research aims to develop a copper recovery process from flotation tailings using high‒pressure leaching (HPL) followed by solvent extraction. Over 94.4% copper was dissolved from the sample (CuFeS as main copper mineral) by HPL in a HO media in the presence of pyrite, whereas the iron was co‒dissolved with copper according to an equation given as C = 38.40 × C. To avoid co‒dissolved iron giving a negative effect on the subsequent process of electrowinning, solvent extraction was conducted on the pregnant leach solution for improving copper concentration. The result showed that 91.3% copper was recovered in a stripped solution and 98.6% iron was removed under the optimal extraction conditions. As a result, 86.2% of copper was recovered from the concentrate of flotation tailings by a proposed HPL‒solvent extraction process.

Ore Minerals and Metal Distribution in Tailings of Sediment-Hosted Stratiform Copper Deposits from Poland and Kazakhstan

“…In tailings from OS ore minerals, smaller sizes are indicated than those in ZM. The small grains facilitated the chemical treatment and metal extraction [20,32] in coarser fractions from the crown of construction, which enable mechanical separation in first step of enrichment. Chalcopyrite grains are the most frequently occurring component in separate grains in both ZM and OS tailings (Figures 4 and 5), useful for copper extraction [32,[46][47][48].…”

Copper Recovery and Reduction of Environmental Loading from Mine Tailings by High-Pressure Leaching and SX-EW Process

“…Extraction of copper from the PLS obtained after HPOL of the concentrate from mine tailings was previously carried out by Han et al [23] using LIX-84I (2-hydroxy-5nonylace-tophenone oxime) extractant. Kerosene was used to dilute the extractant at a phase ratio of 1.…”

“…The Cu-loaded organic obtained from the optimal copper extraction conditions was subjected to stripping experiments where different sulfuric acid concentrations (0.5, 1.0, and 1.5 M) were mixed with the Cu-loaded organic (organic/aqueous phase ratio = 5) at 600 rpm and 15 min contacting time. The stripped solution was analyzed by ICP-OES for the determination of the stripping efficiency and copper concentration [23].…”

“…The effect of sulfuric acid concentration on direct pressure leaching of mine tailings was investigated using distilled water and 0.2-1.0 M H 2 SO 4 . Other leaching conditions were kept the same as in Han et.al [23] at a fixed pulp density of 100 g/L, total pressure of 2 MPa, leaching temperature of 180 • C, and leaching time of 1 h. As shown in Figure 4, the highest achieved leaching rate of Cu was 98.72% when distilled water was used as a leaching medium, while the lowest achieved leaching rate of Fe was 16.31% at the same leaching conditions. The Cu and Fe concentrations in the leachate were 0.23 g/L and 0.28 g/L, respectively.…”

“…The advantages of pressure leaching include fast kinetics, enhanced metal selectivity, and the generation of stable residues [22]. Han et al [23] have already presented in full detail about high-pressure leaching of the concentrate obtained after the flotation of the mine tailings. This study considers highpressure leaching directly on the mine tailings as well as environmental evaluation of the leach residue stability.…”