講演情報
[2501-08-05]Investigation of collectorless flotation and additive roasting conditions for the recovery of copper from copper sulfide ore
○Bekhzod Mirzo Gayratov1[博士課程], Bobur Gayratov1, Labone Godirilwe1, Sanghee Jeon1, Atsushi Shibayama1 (1. Akita University)
司会：三木 一（九州大学）
キーワード：
sulfide ore、collectorless flotation、chalcopyrite、additive roasting、copper recovery
Copper sulfide ores often contain silica and sulfur-rich gangue minerals, complicating flotation and mineral separation. However, these challenges can be addressed using collectorless flotation, which leverages the natural floatability of chalcopyrite (CuFeS₂) and the hydrophilicity of silica. Pyrite (FeS₂), the main sulfur-bearing gangue, can also be effectively depressed under these conditions, reducing sulfur and iron contamination and improving concentrate quality. Chalcopyrite’s floatability is enhanced by air exposure and pre-aeration of the pulp, achieving high copper recovery and grade. However, due to its refractory nature and strong crystal structure, further copper extraction is difficult. Additive roasting is a promising pre-treatment that modifies mineral surfaces and enhances copper recovery during leaching, overcoming challenges posed by passivating layers that hinder direct leaching.This study investigates a combined approach using collectorless flotation followed by additive roasting and leaching to recover copper from chalcopyrite-rich ore. The ore, containing quartz and pyrite, underwent flotation without collectors, achieving 94.5% copper recovery and a concentrate grade of 7.12% Cu from an initial 0.94%. This concentrate was used in roasting tests with additives like KCl and NaOH under various conditions.Roasting at 600 °C for 1 hour followed by leaching in 0.1 M sulfuric acid at 25 °C yielded copper dissolution of 97% with KCl (1:0.1) and 96.5% with NaOH (1:0.05), while keeping iron dissolution below 5%. NaOH proved particularly effective, offering faster reaction kinetics and better environmental performance.