EXTRACTION
Objective: To extract the rock from the mine to be sent to the next stage. Ore extraction can be carried out in two ways:
- • Open Pit Mining (Oxidized Ores)
- • Subway Mining (Sulfide Minerals)
Open Pit Mining
Objective: To extract the rock from the mine to be sent to the next stage of processing (ore) or to dumps (low grade and ballast or tailings). The main sub-processes involved are:
- • Drilling and blasting of the rock.
- • Loading and transportation of materials to their destinations.
Subway Mine Extraction
Objective: To extract the rock from the mine to be sent to the ore processing stage. Subway extraction can be carried out by different mining methods. This choice depends on technical-economic aspects, such as rock characteristics or scale of exploitation. The main sub-processes involved are:
- • Drilling and blasting of the rock.
- • Loading and transportation of ore to the plant.
PROCESSING
Objective: The ore is subjected to several processes aimed at increasing its concentration (metal content) to make its sale possible or to prepare it for the smelting and refining process. There is a great diversity of metallurgical processes, depending on the characteristics of the ore. The main methods are:
- • Sulfides (deep ores): Flotation
- • Oxides (surface ores): Leaching
Flotation
Leaching
SMELTING AND REFINING
Smelting Process: Consists of the separation of the metals contained in the concentrates by a pyrometallurgical process (with high temperatures that melts the concentrate, transforming it from solid to liquid).
In this way, metals are obtained in impure form, with high metal contents. For example, Blister Copper - 99.2% Cu. An important by-product of this process is sulfuric acid, obtained by capturing the gases and transforming them into liquid form.
Refining Process: Consists of obtaining metals in a state of purity such that they are suitable for industrial transformation.
For example, copper cathodes - 99.99 % Cu.
- • Fire refining (pyrometallurgy).
- • Electro-winning refining (EW)
