Hatch has been working for Sierra Gorda SCM (jointly owned by KGHM and Sumitomo) since mid-2012, when it started detail engineering for the molybdenum plant. The mine’s molybdenum feed grade is approximately 900 ppm—significantly higher than the industry average of 100 to 200 ppm. Therefore, for the first five years of operation, the molybdenum concentrate will be extremely rich. For the remainder of its estimated 35-year life, the plant will continue to process 110,000 t/d of ore with an option to expand to 190,000 t/d.
A unique attribute of the Hatch-designed molybdenum plant is its as-built capacity. The design is sophisticated and flexible enough to operate from year one to the end of the mine life with only minor piping changes (no major upgrades) required to process the different throughputs coming from the collective copper/molybdenum main concentrator.
The picture shows Sierra Gorda tailings thickeners with process water ponds in the background, for which seawater will be piped 142 km from a power plant cooling facility on the Pacific coast.
To achieve the project’s business goals and 2014 production target, the mine and concentrator activity had to align with a very steep ramp-up curve. Hatch’s South American operational performance team was engaged at Sierra Gorda since March 2013 and, in November 2013, it mobilised a small site team to review the pre-commissioning and commissioning plan, and to assist in startup preparations. For 30 days, the team integrated pre-commissioning and commissioning data with existing schedules in Hatch’s iPas CS system, to demonstrate progress, identify potential risks, and advise on developments to minimise startup delays.
In January 2014, Hatch was awarded additional work to provide ongoing support with pre-commissioning, commissioning and operational readiness for the multi-billion-dollar copper and molybdenum concentrator project. Hatch provided a full-time site team of 20 (with specialists from Chile, Peru and Canada) to support this effort.
This team supported the operations group in further development of detailed schedules and checklists to enable efficient pre-commissioning turnover as well as execution of commissioning work. The team also helped Sierra Gorda audit spares, develop health and safety standards and isolation procedures, and facilitate overall plant operational readiness activities.
Sierra Gorda is an open-pit, 110,000 t/d operation in northern Chile that will produce copper and molybdenum concentrates. The project is located about 170 km northeast of the coastal city of Antofagasta, at an altitude of 1,626 m in the Atacama desert.
The mine has an expected life of 35 years, over which it will produce copper and molybdenum concentrates in two separate streams. For the first five years, the very high-grade molybdenum concentrate will produce significant revenue for the operation.
The focus on efficiency paid off — Sierra Gorda is on track to produce first copper concentrate this year.
