Air-cleaning and dust control company Actom Air Pollution Control has been awarded a R200-million contract to provide a range of filtration equipment for the control of fumes and dust in the Phase 2 smelter expansion at Xstrata’s Lion ferrochrome complex.

This is the largest contract to be awarded to Actom in its 43-year history.

“We provided the air pollution control plant for the Lion ferrochrome complex Phase 1 expansion [five years ago] and we have been fortunate to have been selected again for Phase 2,” says Actom sales manager Gerard Pretorius.

Despite minor modifications, the new plant will be identical in design, content, technology and capacity to the first, but the scope of the contract has been substantially expanded, compared with the initial contract.

“The Phase 2 contract includes the supply of all equipment involved, with the sole exception of the fan motors, which will be free-issued to us by Xstrata. Previously, virtually all the mechanical and ancillary equipment was free-issued,” Pretorius explains.

The present contract, awarded in early November and scheduled for completion in mid-2013, comprises the design, manufacture, supply, installation and commissioning of three suction reverse air bag filter bag houses (two for fume and dust extraction in the two rotary kilns and the other for fume and dust extraction in the rotary drier), seven pulse jet bag filters for dedusting in the mill and prewetting operations, all ducting and materials handling equipment serving these installations, as wells as fans and stacks.

“The combined air-moving capacity of the reverse air bag houses for the rotary kilns and the rotary drier will be 1.4-million cubic metres an hour, and the total capacity of the seven pulse jet bag filters will be 75 000 m3/h,” says Pretorius.

All the bag filters are thermally insulated, and those in the rotary kiln bag houses will operate in temperatures of about 140 °C, while the bag house for the rotary drier will operate in an average temperature of 180 °C.

“Cleaning of the bags is done off-line through automatic programmable-logic-controller dampers, and the cleaning of each compartment is carried out while the rest of the compartments are in operation. Maintenance work is completed on-line by isolating each compartment concerned as the compartments are independent modules,” he concludes.