Copper beneficiation involves a meticulous series of physical and chemical processes designed to extract copper from its ores. The process encompasses crushing, grinding, gravity concentration, and flotation concentration. It all begins with the mining of copper ore, which can in form of oxide, sulfide, or carbonate minerals. Vibratory feeders transport the mined ore to jaw crushers and cone crushers, transforming it into finely crushed and ground particles.
To achieve a finer granularity, the ore undergoes a mill grinding process utilizing key equipment such as ball mills and rod mills. Subsequently, the finely ground copper ore is mixed with water and chemical reagents in large cylindrical tanks equipped with stirring mechanisms. This facilitates the creation of a slurry that is evenly distributed, preventing settling. Through selective attachment, the chemical reagents render the copper minerals hydrophobic, enabling their separation from the gangue minerals.
Froth flotation is the most commonly used technique, which involves adding chemical reagents to the crushed ore to create a froth on the surface of a flotation cell. The copper minerals adhere to the froth, while the gangue minerals sink to the bottom.
After flotation, the copper concentrate still contains impurities and necessitates further refining. High-efficiency concentrators, also known as thickeners, are employed for this purpose. These concentrators remove water from the copper concentrate, thereby increasing the copper concentration. The process involves sedimentation in large tanks, wherein solids settle at the bottom while water is removed from the top. Rakes are utilized to eliminate the settled solids, which are subsequently pumped for further processing. The recycled water finds purpose in the flotation process, ensuring responsible water usage.
The concentrated copper slurry proceeds to a filter press to eliminate any remaining water and further enhance the copper concentration. The filter press, a machine that utilizes pressure to separate solids from liquids, receives the slurry, spreading it across a series of filter plates. Under high pressure, the plates are pressed together, expelling water and yielding a concentrated copper cake.
Following filtration, the copper concentrate is directed to a dryer to eliminate any residual moisture. Rotary dryers leverage hot gases for drying, while flash dryers employ high-velocity hot air to achieve rapid moisture removal.