ABB, a leading power and automation technology group, has commissioned an upgrade to Vale S.A.’s existing Clarabelle dual-pinion, semi-autogenous (SAG) mill in Ontario, according to company officials.
The Clarabelle mill reduces ore size at the nickel and copper mines near Sudbury. Vale’s Sudbury operations are primarily underground nickel sulphide mines with integrated mining, milling, smelting and refining operations.
A prominent mill characteristic is its accepting nickel-copper ore from various sources to produce a nickel-copper concentrate and copper concentrate for further processing. Ore size is further reduced in semi-autogenous mills, rod mills and ball mills where all milling is wet.
First awarded in 2010, the project is the largest of several turnkey assets completed for Vale in Canada. This project involved upgrading a 10-m diameter SAG mill that turns at 11.2 rpm and had reached its end-of-life with a newer, more robust system.
ABB replaced all of the electrical equipment including 5,500-kW motors, converter, transformer, motor control centers, switchgear and mechanical auxiliary equipment such as the cooling system — pump skid, chillers and fin-fan heat exchangers. The company also modified the existing foundation and air-clutch coupling to adapt it to the new motors. A number of SAG mill applications were implemented to facilitate the operation and maintenance of the SAG mill.
ABB built an additional structure to house all new equipment for mill system integration. Engineering and construction extension included excavation, foundation, civil, structural steel and architectural works as well as insulation, fire system, lighting, heating, ventilation and air conditioning.