Mastering key copper ore beneficiation processes to achieve efficient resource recovery

Transforming copper ore into qualified smelting feedstock requires a systematic and efficient mineral processing workflow. Given the generally low copper grades in natural ores, enrichment through scientific mineral processing is essential.

The process determination begins with accurately identifying the ore type: Sulfide copper ores with good floatability are primarily treated by flotation; surface-hydrophilic oxide copper ores often require sulfide flotation or hydrometallurgical leaching processes; while mixed copper ores necessitate combined processes for recovery.

Processing commences with pre-treatment to achieve thorough liberation of copper minerals from gangue. Ore typically undergoes two to three stages of crushing to reduce particle size to 8-15 mm before entering grinding mills for fine grinding. Grinding fineness is critical and must be adjusted based on mineral grain size distribution, ranging from 50% to over 80% passing -200 mesh. The ground slurry is then classified, with qualified fines proceeding to the core separation stage.

For the predominant sulfide copper ores, flotation is a well-established process. By adding lime (adjusting pH to 9-11), xanthate collectors, frothers, and inhibitors, the flotation machine exploits differences in mineral surface hydrophobicity. Through multiple stages of roughing, scavenging, and cleaning operations, copper is efficiently separated and concentrated.

Processing oxidized copper ores presents greater challenges. The sulfidation-flotation method is commonly employed, involving surface treatment with sodium sulfide followed by conventional flotation. For low-grade, refractory ores, the leaching-solvent extraction-electrowinning (L-SX-EW) process proves more economical, producing high-purity cathode copper directly through acid leaching, solvent extraction, and electrolysis.

Mixed ores require flexible technology combinations, such as priority flotation (sulfides first, then oxides) or mixed flotation (simultaneous recovery), sometimes integrated with flotation and leaching.

Finally, the flotation concentrate slurry requires dewatering. It is first thickened in a thickener, raising the underflow concentration to 40%-60%, then dewatered through a filter press to produce a copper concentrate filter cake with a moisture content below 10%-20%.

In summary, successful copper ore beneficiation is a systematic process spanning from ore characterization to concentrate production. Its core lies in conducting systematic beneficiation tests to tailor technically feasible and economically viable processes for specific ores, thereby achieving efficient resource recovery.