South African-Chinese ferrochrome producer ASA Metals has commissioned Helsinki-listed minerals processing plant designer Outotec to deliver ferrochrome production technology at its Dilokong chrome mine expansion project in Limpopo Province.
Outotec will design and deliver a chromite ore pelletiser plant and two preheating kilns valued at an estimated €25-million.</pcs cone crusher spare>
The scope of delivery includes the licence, basic engineering, supply of key equipment, supervision of the installation and commissioning, as well as training of ASA Metals production personnel.
Tenova Pyromet and Metix will provide all equipment outside Outotec’s scope as well as construction and installation of the new plant.
„The new plant will be based on Outotec’s ferrochrome process, which recently won the CleanTech Finland 2008 award. The award was given to the company because it is seen as a pioneer in environment-friendly policies, products and processes and because the business promotes sustainable development,“ says Outotec vice-president for base metals and ferroalloys Jorma Daavittila.
„It has been estimated that our technology has reduced carbon-dioxide emissions at Outokumpo Tornio Works by six-million tons and at our ferrochrome plants in South Africa by five-million tons. The process significantly reduces the consumption of electric energy when compared to conventional processes,“ explains Outotec president and CEO Tapani Järvinen.
The pelletising section will use Outotec’s steel belt sintering technology, and the two 66-MVA-ferrochrome smelting furnaces will be equipped with the preheating kiln technology.
The plant is designed to produce 600 000 t of chromite pellets annually and it is expected to be commissioned in the second half of 2009.
„Pelletising and sintering play a vital role in modifying smelter behaviour of ore as good ore uniformity results in consistent furnace performance, lower power costs and higher recovery yields. The furnace is an effective multicompartment oven through which the pellets are carried on a perforated steel belt conveyor. This treatment gives the pellets a strong structure that withstands mechanical and thermal treatment. Owing to the use of cooling gases in the front-end compartments, and low exhaust gas temperatures, the external energy consumption of the furnace is very low.
„The steel belts sintering system can also be adapted to handle iron ore, manganese ore and steel plant dust.
„The ferrochrome process has a cost-efficient production method. By effectively preheating the charge to the smelting furnace, the capacity of the furnace increases because of decreased specific energy consumption and stabilises operational conditions. The smelting furnace and feeding system, including the preheating stage are gas-tight, which helps provide good working conditions at the plant and reduces its environmental impact,“ says Outotec.
„The new ferrochrome plant is the eleventh South African plant using Outotec’s steel belt sintering technology and the ninth using its preheating kiln technology. Because of its energy efficiency, the technology has been a success in the global market, and is currently used to produce 35% of the world’s ferrochrome,“ Järvinen concludes.