Copper ores are classified into three types based on their oxidation rates: sulfide ores, oxidized ores, and mixed ores. The main mineral processing method is flotation, while for difficult to select mixed copper ores and difficult to select oxidized ores, wet metallurgy is often used for treatment.
The commonly used process flow for copper ore flotation, in terms of the number of separation stages, mainly consists of one stage and multiple stage separation processes.
There are various types of personalized processes, mainly influenced by the following factors:
- There are many types of copper sulfide, including chalcopyrite, chalcopyrite, bornite, chalcopyrite, and arsenopyrite. The order of their interaction with yellow medicine is chalcopyrite>chalcopyrite>bornite>pyrite;
- The impact of secondary copper deposits and their degree of oxidation;
- The influence of embedding particle size, the finer the particle size, the harder it is to float;
- Copper containing polymetallic ores, including copper sulfide iron ore, copper molybdenum ore, etc.
Copper sulfide ore beneficiation process
Pre selection stage: The block shaped sulfide ore is crushed to a particle size of around 12cm using a jaw crusher or cone crusher. This process may involve multi-stage crushing and requires the use of screening equipment.
Selection stage: The slurry discharged from the ball mill is transported to the mixing tank, where coarse flotation reagents are added. After sufficient stirring and activation in the mixing tank, it is fed into the flotation machine for flotation operation. Collector, regulator and foaming agent are added in the flotation process, and useful minerals are concentrated in the foam and scraped out by the flotation machine scraper.
Post selection stage: Concentrate and dehydrate the mineral rich slurry obtained from the flotation workshop through mechanical dehydration, and then transport it to the smelting plant for smelting, ultimately obtaining copper metal with a grade of up to 99.0% -99.7%.
Copper oxide ore beneficiation process
Flotation process
Pre selection stage: Similar to the pre selection stage of sulfide ore, it also involves pre-treatment such as crushing.
Selection stage: According to the flotation reagents used, there are five common flotation methods: sulfide flotation, fatty acid flotation, amine flotation, emulsion flotation, and chelating agent neutral oil flotation.
Post selection stage: No special post-treatment mentioned, it is speculated that dehydration and other operations will also be carried out and sent to the smelting plant.
Extraction process
Heap leaching process: The mined ore is crushed to a certain particle size by crushing equipment and directly subjected to heap leaching. Place the oxide ore (mixed with some sulfide ore) on the leaching pad and spray a strong acid solution to allow it to permeate with the crushed stone. Over time, copper in the crushed stone leaches into the solution and becomes precious liquid. After collection, it is pumped to solvent extraction equipment for further purification.
Pool leaching process: Use a concentrated sulfuric acid solution to leach 1-2% copper containing oxidized ore (with a particle size of -1cm) in the leaching tank. Due to the high concentration of copper in the leachate, it can be directly used for electroplating copper.
In situ leaching process: During in-situ leaching, the well spacing is generally 30x30cm (or 15 × 7.5m), the drilling diameter is 15-25cm, and plastic pipes are installed in the holes to directly pass through the ore body. The leaching agent flows into the ore body along the plastic pipes, and the leaching solution is pumped back to the surface from the bottom of the ore body. Suitable for processing residual ores from old mines or unmined oxidized copper ores and depleted copper ores.
Stirring leaching process: Stirring is carried out in a leaching tank equipped with a stirring leaching device, using a concentrated sulfuric acid solution to leach fine-grained (-75um accounts for 90%) oxidized ore or sulfide ore roasted sand. There are two main leaching methods: air agitation and mechanical agitation. Due to the small particle size of the feed and sufficient agitation, agitation leaching is faster and has a higher leaching rate than tank leaching.
The beneficiation process of copper mines varies depending on the type of ore. Copper sulfide ore is mainly processed through steps such as crushing, grinding, flotation, dehydration, and smelting; There are two main processes for copper oxide ore: flotation and leaching. There are multiple flotation methods to choose from in the selection stage of the flotation process, and the leaching process is divided into heap leaching, pool leaching, in-situ leaching, and agitation leaching. Each process has its specific operating procedures and applicable conditions.