Copper ore enrichment method

Copper ore enrichment is a key process to increase the copper content in copper ore to reach an economically usable level. Most copper ores in nature have low grades, and direct smelting costs are high and inefficient. Enrichment can effectively separate copper minerals from impurities such as gangue, thereby increasing the utilization value of copper resources.

Common copper ore enrichment methods are mainly flotation, gravity separation, magnetic separation and leaching. Each enrichment method is different. Let's learn about it together.

1. Copper ore flotation enrichment method

The flotation of copper ore is based on the difference in the physical and chemical properties of the surfaces of copper minerals and gangue minerals, especially the difference in surface wettability. By adding flotation agents, such as collectors, frothers, adjusters, etc., the surface of copper minerals is made hydrophobic and can be attached to bubbles, while the surface of gangue minerals is hydrophilic and remains in the slurry, thereby achieving the separation of copper minerals and gangue.

The process is usually to first crush the large pieces of ore to gradually separate the copper minerals to the state of monomer dissociation. It is necessary to crush first and then grind. Generally, the grinding particle size needs to reach -200 mesh, accounting for 60%-80%. Then the pulp is adjusted to adjust the pulp concentration to 20%-40%, and the pH value is adjusted. For the flotation of sulfide copper ore, the pH value is usually controlled at 7-11. After adding the reagent, the slurry is sent to the flotation machine. Under the action of stirring and aeration, the copper minerals adhere to the bubbles and float to form a foam layer. The foam is scraped off to obtain the copper concentrate, and the tailings are discharged.

Flotation enrichment of copper has strong adaptability to different types of copper ores. Whether it is sulfide copper ore or oxidized copper ore, it can achieve good enrichment effect, and can realize the comprehensive recovery of multiple useful minerals, such as copper, lead, zinc, etc. in copper-lead-zinc polymetallic ores.

2. Copper ore gravity concentration method

The gravity concentration of copper ore is mainly due to the difference in density between copper and other minerals (generally, the density of copper is greater than that of gangue minerals), and then the minerals of different densities are separated by gravity, centrifugal force and other forces.

The process is to first crush and finely grind the ore blocks, and then enrich them through gravity separation methods such as jigs, shaking tables or chutes. Among them, jig gravity separation uses alternating water flow up and down to separate mineral particles according to density, with heavy minerals settling in the lower layer and light minerals in the upper layer; the shaking table is under the action of reciprocating motion and lateral water flow, so that the mineral particles are divided into zones according to density and particle size, thereby achieving copper mineral enrichment.

This enrichment method is simple, low-cost, and has little environmental pollution. It is suitable for processing coarse-grained copper ores.

3. Copper ore magnetic separation and enrichment method

The magnetic separation and enrichment of copper ore is mainly aimed at enriching and purifying some copper ores containing magnetic separation minerals, such as pyrrhotite, etc., or making copper minerals magnetic through magnetic roasting, and using the difference in mineral magnetic properties. In an uneven magnetic field, magnetic minerals are attracted by the magnetic field and separated from non-magnetic minerals.

The process of magnetic separation and enrichment is to first pre-treat (crushing and grading) the mineral particle size to achieve monomer dissociation, and then feed it into the magnetic separator. According to the magnetic strength of the mineral, different magnetic equipment is used for separation. Usually, weak magnetic separation is used to recover strongly magnetic minerals; strong magnetic separation is used to recover weak magnetic minerals. For example, for ores containing magnetic copper minerals, weak magnetic separation is first used to recover strongly magnetic minerals, and the tailings are then subjected to strong magnetic separation to recover weakly magnetic copper minerals.

For copper ores containing magnetic minerals, this method can efficiently separate magnetic minerals and improve the quality of copper concentrates. It can also be used in combination with other mineral processing methods to improve the overall recovery rate.

4. Chemical leaching enrichment method for copper ore

Chemical leaching enrichment of copper ore uses chemical reagents to react with copper ore to dissolve copper minerals into the solution and separate them from insoluble gangue minerals. For copper sulfide ores, sulfuric acid, iron salts, etc. are often used as leaching agents. Under acidic conditions, copper sulfide reacts with sulfuric acid and oxygen to form copper sulfate solution; for oxidized copper ore, dilute sulfuric acid can be used for direct leaching.

The ore dressing process is to crush and grind the ore, mix it with the leaching agent, and leach it under certain temperature, pressure and stirring conditions. After leaching, a copper-containing solution is obtained by solid-liquid separation, and then copper is recovered from the solution by extraction, ion exchange, electrolysis and other methods.

The chemical leaching enrichment method of copper ore is suitable for processing low-grade, complex and difficult-to-select copper ores. It can effectively extract copper wrapped by other minerals, and can be carried out at normal temperature and pressure, with relatively low energy consumption.

These enrichment methods have their own characteristics. In practical applications, it is necessary to select a suitable enrichment method based on factors such as ore properties, grade, and scale. In order to determine the process method, it is recommended to conduct mineral processing tests and design a suitable enrichment plan through test analysis.