Turkey top envoy goes to Niger in bid to secure uranium supplies
The trip comes after Niger’s military government withdrew mining rights from Canadian and French companies to develop uranium deposits.
ACS 6000 medium voltage drive improves availability for biggest mine hoist in China
ABB provided two hoist systems for the main shaft, with each hoist pulley having a diameter of 5.7 meters, a payload of 45 tons, and a motor power of 7000kW. It utilizes MV AC-DC-AC direct torque control (DTC) technology and is the biggest hoist system ever installed in China.
In June 2011, ABB started the installation and no-load commissioning of the mine’s No. 2 main shaft hoist, which covers the mechanical part, the motor, the control system, as well as the ACS 6000 MV drive and brake control system. The half-speed under full-load function is designed to maintain the safety of the hoist system and a continued production in case of failure of the hoist’s drive system. Half-speed with full-load redundancy has been available for systems using DC drives and AC-AC direct conversion frequency drives, but this specific function has never been realized before for hoist systems based on AC-DC-AC frequency conversion drives.
Stephen Zhu, Manager of ABB’s Mining and Minerals business in China, said, “ABB designed an ACS 6000 MV drive system using two independent sets of active rectifier units (ARU) and inverter units (INU) for the Ma JiaLiang project. Under normal conditions, the two operate together, providing power to the motor. If one fails, a switch cabinet will connect the redundancy operation mode and start the operational set. This is a significant achievement which can greatly reduce shutdown time, providing our customers continuous production with improved reliability.”
ABB (www.abb.com) is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 130,000 people.
