Introduction to Copper Ore Processing

Copper ore resources are divided into two main categories: sulphide copper ores and oxide copper ores. Sulphide copper ores account for over 90 per cent of the total volume mined and are the primary source of industrial copper extraction. Copper ore beneficiation processes are well-established and highly adaptable; drawing on the differences in ore types, a comprehensive processing system has been developed that is centred on flotation, supplemented by gravity separation and wet leaching. It is one of the most widely applied and technically sophisticated process systems in non-ferrous metal beneficiation.

The core of sulphide copper ore beneficiation is the flotation process. The raw ore undergoes crushing and two-stage closed-circuit grinding to achieve individual liberation of minerals; by precisely controlling the grinding fineness, over-grinding and slime formation—which adversely affect flotation efficiency—are avoided. Floating generally employs either priority flotation or mixed flotation processes: for single-mineral copper ores, a conventional flow sheet comprising one roughing, two scavenging stages and two concentrating stages is commonly used; for copper-sulphide co-occurring ores containing associated pyrite, efficient enrichment of copper minerals is achieved through lime sulphur suppression, selecting copper whilst discarding sulphur.

For complex polymetallic copper ores, such as copper-lead-zinc or copper-molybdenum ores, staged priority flotation and asynchronous reagent regimes are employed to sequentially separate valuable metals such as copper, molybdenum, lead and zinc, thereby achieving comprehensive resource recovery. In some cases, coarse-grained native copper may be pre-concentrated using gravity separation to reduce the flotation load.

Oxidised copper ores are difficult to process and present high flotation challenges; therefore, wet processes such as acid leaching, heap leaching and extraction-electrowinning are commonly employed, making them suitable for the development of low-grade oxidised copper resources. Copper concentrate produced by flotation undergoes thickening and filter press dewatering to form high-grade, compliant concentrate. Modern copper mining projects are equipped with comprehensive water recycling and dry tailings disposal systems, enabling efficient, energy-saving and environmentally friendly production.