Vertical motion: Underground mining gets a safety upgrade
Mine hoist system challenges include speed, reliability, and safety.
Zurich, Switzerland – Mine hoist systems , a key component in underground mining, are the most efficient means for transporting crushed ore to the surface from areas hundreds or thousands of meters below ground. These vertical motion control and machine safety applications are often the only way to move staff and equipment up and down shafts. Challenges include the need for speed, reliability, and safety in the round-the-clock process; the efficiency of the system determines productivity and eventual profitability.
|Mine hoist systems are the most efficient means for transporting crushed ore to the surface from areas hundreds or thousands of meters below ground. Source: ABB|
At the heart of the mine hoist system are three technologies:
• ABB ACS6000 ac drive system controls the torque and speed of giant ac motors that move equipment, people, and ore up and down the shafts. Although hoists require huge amounts of electricity, the drive system has little impact on the surrounding power network and does not affect power quality for other consumers;
• Hoist-control system based on the AC800M industrial controller, part of the ABB System 800xA automation system platform; and
• ABB Hydraulic Disc Brake System with controlled retardation to ensure safe braking force in all operating situations (direction, speed, load and friction).
ABB says it has delivered more than 600 mine hoist systems worldwide, and that it’s the only supplier with the capability to supply electrical and mechanical equipment together.
Kiruna, Sweden has the world’s largest underground iron-ore mine. Operated by LKAB, a state-owned mining company, it has 11 mine hoists supplied by motion control provider ABB , and is the largest hoisting plant in the world. ABB says it’s upgrading the mine’s four underground hoists and has supplied a seventh surface hoist to enable LKAB to boost production 25% to 33 million tons of crushed ore per year.
The Esterhazy potash mine in Saskatchewan, Canada, is run by Mosaic, a fertilizer maker, and is among the world’s largest potash mines. ABB has upgraded one of two production shafts to increase skip capacity 50% and boost production by 1.1 million tons per year. An ABB 8.6-megawatt (MW) motor and drive comprise the world’s most powerful hoist system, improved energy efficiency at the Esterhazy mine by 5 to 8%, ABB says; despite enormous size and power requirements, it maintains grid stability without additional power correcting equipment.
The automation supplier says it also has presence in the Sudbury Basin in Ontario, Canada, involved in projects for two mining majors there: Xstrata and Vale Inco. Xstrata’s Nickel Rim South mine will open this year and achieve full annual production capacity of 1.25 million metric tons of crushed ore (nickel, copper, palladium and platinum) in 2009. ABB supplied four mine hoist systems for the main production shaft, service shaft, and two auxiliary hoists.
At Vale Inco’s nearby Totten mine, scheduled to open in 2010 after a closure lasting more than three decades, ABB provides a power and automation solution for the site, including a mine hoist system for the new production shaft. This follows ABB’s delivery five years ago of a mine hoist system for a new delivery cage for Vale Inco’s Creighton mine. Located two kilometers underground, the mine is the deepest in the Western Hemisphere. The solution has reduced energy costs by approximately $150,000 a year and improved the comfort of the journey underground.
Also read, other ABB news:
Green drives: Energy efficient drive systems boost copper mine productivity
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