The ore processing plant has three lines able to process more than 4.5 million tonnes of polymetallic and copper ore per year. It is in operation 24 hours a day and 365 days a year. The ore from the three mines (Aguas Teñidas, Magdalena and Sotiel) is processed at this plant.
Stages of the process:
Stockpiling and Grinding
The ore extracted from the mine is deposited in a stockpiling zone where it is classified. From here it is sent to the grinders to reduce its size and then it is taken by conveyor belt to three warehouses: two domes and one reclaimer.
These large storage systems have two important functions: to prevent the spread of dust and to maintain ore reserves for the continuous operation of the processing plant. The stored ore leaves on conveyor belts to the crushing stage in the processing plant, where the size of the ore is reduced in different stages.
On lines 1 and 2, the first stage of the grinding takes place in an SAG (semi-autogenous) mill and the second, in a ball mill. The final stage is the tertiary grinding, performed in vertical mills which, using small ceramic balls and friction, reduce the size of the ore to the values required for the flotation stage. Line 3 of the plant has two ball mills which perform the same function prior to the flotation stage.
During the flotation stage, reagents such as collectors, modifiers and frothers are added, and air is injected, forming small bubbles to which the lead, zinc and copper sulphide particles selectively attach themselves.
Thickening and filtration
The slurry formed in the flotation stage passes to the thickeners and finally to the filtration stage, where any remaining water is removed. The result is the final product marketed by the company: copper, zinc and lead concentrates.
Tailings from the flotation are thickened to remove the water and used for the paste which serves to backfill the mining chambers. The residue from the tailings is stored in the paste deposit.
In turn, the copper, zinc and lead ore concentrates produced by Sandfire MATSA are sent, via the port of Huelva, to their final destination.
Chemical and metallurgic laboratories
The company also has its own metallurgic and chemical laboratory. The metallurgic laboratory, which forms part of the metallurgy and process control department, is a key element in the optimisation of the plant processes, and for the development of new processes.
In turn, the chemical laboratory provides the analytical data necessary for decision-making in the areas of mine production, exploratory perforations, the marketing of copper, zinc and lead concentrates, process control and even for the metallurgic balance of the plant and/or environmental control.
Sandfire MATSA has two paste plants, one at Aguas Teñidas and the other at Magdalena. It also has a shotcrete plant which produces and supplies this product to the two mines.