​A Comprehensive Review of Copper Ore Processing Technology

Copper ore resources are essential basic materials and strategic commodities for national economies and defense construction. China has identified copper resources reserves of 34.95 million tons, ranking sixth globally. Copper ore processing technology encompasses both beneficiation and smelting, involving a variety of advanced processes and equipment aimed at efficiently extracting copper resources while reducing energy consumption and environmental pollution.

Copper Ore Beneficiation Technology

Copper ore beneficiation technologies include crushing and grinding, flotation, magnetic separation, and gravity separation. The crushing and grinding stage employs energy-efficient equipment such as high-pressure grinding rolls and autogenous mills. Through multi-stage crushing and stage grinding processes, the liberation degree and selectivity of the ore are enhanced, creating favorable conditions for subsequent beneficiation operations. In the beneficiation stage, gravity separation leverages the density differences of minerals, using shaking tables and sluices to achieve stratification and separation of minerals. Magnetic separation relies on the magnetic properties of copper ores, using magnetic separators to separate magnetic and non-magnetic minerals. Flotation technology, which is particularly suitable for the processing of fine-grained copper ores, utilizes the differences in the physicochemical properties of mineral surfaces to selectively attach valuable minerals to air bubbles for separation.

Copper Ore Beneficiation Process Flow

The general beneficiation process flow includes the mining of raw ore, multi-stage crushing, storage in ore bins, feeding, ball milling, classification, flotation, re-flotation, and thickening sampling. Depending on the type of ore, different beneficiation methods are employed. For example, single sulfide ores commonly use mixed flotation, preferential flotation, and other methods; oxidized ores focus on combined flotation and hydrometallurgical treatment; mixed ores are processed by flotation to produce copper concentrate, followed by hydrometallurgical treatment.

Single and Multi-Metal Flotation Processes

For single-metal ores, the flotation process is selected based on the characteristics of the useful minerals' dissemination size in the ore. For non-uniformly disseminated ores, which are prone to sludging and have different hardness levels between valuable minerals and gangue, roughing and scavenging operations can be conducted. Coarse concentrate and middlings are reground and reselected to produce qualified concentrate. For multi-metal ores, the flotation process involves preferential flotation, mixed flotation, and separation flotation to efficiently extract multiple metals.

Oxidized Copper Ore Flotation Process

The flotation methods for oxidized copper ores are diverse, including direct flotation and leaching flotation. Direct flotation uses fatty acid or amine collectors to complete the beneficiation process directly. Leaching flotation involves oxidizing and heating the ore and adding chlorinating agents and reducing agents to achieve mineral leaching, further improving copper recovery rates.

Copper Smelting Technology

After beneficiation, copper concentrate can be refined and smelted. Common smelting technologies include pyrometallurgical and hydrometallurgical processes. Pyrometallurgical smelting, a traditional method relying on oxidation and reduction reactions at high temperatures to extract copper in metallic form, is suitable for high-grade copper ores. Hydrometallurgical smelting, which has gained rapid development in recent years, involves solvent extraction and electrolysis steps to extract copper in ionic form from ores, followed by electrolytic deposition to produce metallic copper. This method is characterized by low energy consumption and minimal environmental pollution and is particularly suitable for processing low-grade, complex, and difficult-to-select copper ores.

In summary, copper ore processing technology, from beneficiation to smelting, involves a variety of advanced processes and equipment aimed at efficiently extracting and sustainably utilizing copper resources. As technology continues to advance, copper ore processing will further develop towards higher efficiency and environmental friendliness.