Minera San Cristóbal S.A.

Minera San Cristóbal uses the state-of-the-art technology available for the mining industry. It is a low-grade but bulk mineable deposit. Therefore, the open-pit mining method is used.

In the open pit extraction area, radar technologies are applied for slope monitoring. The mining teams have on-board computers that incorporate image recognition and georeferencing technology to ensure compliance with safety standards in the operation of the equipment and the application of real-time optimization algorithms for each of the unit operations that ensure the supply of mineral to the plant within established parameters and achieve the operational efficiency of the mine fleet.

MSC produces around 1,500 metric tons/day of zinc-silver and lead-silver concentrates.

This means that it moves a daily average of 150,000 tons of rock, 52,000 tons of which go to the concentration plant for treatment. The concentration plant consists of a primary crusher, a 1.7 kilometer-long conveyor belt, a giant dome for dust suppression, a milling circuit with a SAG (semi-autogenous) mill, two ball mills, cyclone banks for the re-circulation of the load, a differential flotation circuit where the two types of concentrates are separated and a filtration and drying plant.

The plant’s nominal production capacity is 52,000 tons of dry mineral per day. The plant operates 24 hours per day the whole year round, except on the days programmed for maintenance work.

The minerals containing the elements produced by MSC appear in the form of sulfides and oxides. Only the sulfides are treated in the plant of concentration through flotation. The basic composition of sulfides is sulfur combined with different metals, in our case zinc, lead and silver. The products coming out of the plant are zinc sulfides (sphalerite) and lead sulfides (galena). Silver sulfide (argentite) is found in both products.

The objective of the plant is to separate these sulfides from each other and from the tailings or sterile material through the sequential phases of crushing, milling, differential flotation and filtering in order to obtain two enriched concentrates that are dry and ready to be commercialized.