Solvent Extraction Studies of Copper from a Heap Leach Liquor Using Mextral 5640H

Abstract

In this study the extractive capability of Mextral 5640H was investigated for extraction of copper from a heap leach liquor. In this regard, the influence of parameters such as pH (0.2–2.8), extractant concentration in kerosene diluent (5%–15% v/v), temperature (25–70 °C), contact time (0–300 s), stirring speed (100–1200 rpm), phase ratio (O/A) (0.6–1.8) and Cu initial concentration (0.5–2 g/L) in the leach liquor were examined and optimized. The findings demonstrated that the Mextral 5640H extractant had a very high efficiency and selectivity in copper extraction from the leachate. 98.17% Cu, with less than 0.5% of Fe and Mn, were extracted at pH 1.6, 10% (v/v) Mextral 5640H concentration, ambient temperature (25 °C), 400 rpm stirring speed, 2 min contact time and an O/A phase ratio of 1:1. Under equilibrium conditions it was found that one mol of Cu is extracted by 7 mol of Mextral 5640H. Additionally, analysis using a McCabe–Thiele diagram suggests a two-stage extraction to reach the maximum extraction of copper (99.5%) from the leachate at operational condition using industrial mixer-settlers. Furthermore, a thermodynamic study was conducted, and the measured values of ΔH = 15.13 kJ/mol, ΔG = −6.95 kJ/mol and ΔS = 74.10 J/mol/K indicate an endothermic, spontaneous nature and high affinity of copper extraction.

Removal of Nickel from Nickel Sulfite-Fire Assay Dissolution Filtrate Through Precipitation

“…The oxime functional groups exhibited a notable affinity for metal ions, particularly Cu, contributing to the high extraction efficiency of 97% as described and compared in the literature. , The resulting aqueous phase, termed the raffinate, revealed a Cu concentration of 800 ppm as determined by inductively coupled plasma–optical emission spectroscopy (ICP–OES). A comparative analysis with Acorga M5640 and Mextral 5640H underscored LIX 63–70s efficacy demonstrating notably faster equilibrium conditions . Furthermore, the previous study highlighted the pH dependency of Cu extraction, emphasizing the influence on Acorga M5640 and Mextral 5640H performance .…”

“…A comparative analysis with Acorga M5640 and Mextral 5640H underscored LIX 63–70s efficacy demonstrating notably faster equilibrium conditions. 21 Furthermore, the previous study highlighted the pH dependency of Cu extraction, emphasizing the influence on Acorga M5640 and Mextral 5640H performance. 20 This research, which reported the extraction of 97% Cu using LIX 63–70 at room temperatures for a contact time of 15 min, provides valuable insights into the effectiveness of the solvent as an extractant for Cu under specific conditions, contributing to the broader understanding of SX processes.…”