Minerals and materials processing technology specialist IMS Engineering has introduced a slag jaw crusher which it believes is ideally suited to the crushing of ilmenite slag in order to produce titanium dioxide feedstock. The crusher, which was engineered by IMS Engineering’s Kawasaki comminution technology partner EarthTechnica Company Limited (ETCL) of Japan, is unique in the market and specifically developed for the processing of ultra abrasive slag containing uncrushable lumps of metal, IMS Engineering marketing and customer support manager Shannon McEwan says.
The Kawasaki EarthTechnica slag jaw crusher has a strong home-ground track record in Japan. It has, amongst others, been in successful operation at a steel plant crushing slag and smelter refractories, McEwan says.
Currently, the South African based producers of titanium dioxide (TiO2) feedstock produce TiO2 slag via the smelting of ilmenite, involving the carbonaceous reduction of ilmenite to achieve a slag with a TiO2 content of around 85%, and a high-purity pig iron as co-product. Non-magnetic heavy minerals such as zircon and rutile are processed in separate circuits.
The cooled ilmenite slag is then crushed, milled and screened in order to produce the requisite fine fractions for the chloride and sulphate pigment processes.
“The Kawasaki EarthTechnica slag jaw crusher would be used in the primary crushing application. It is fitted with extra-thick jaw liners to reduce the mean time between liner changes in this abrasive crushing environment, reducing the cost of operation. The heart of the crusher is the large hydraulic cylinder that replaces its toggle plate protection system, protects the machine body and shortens recovery time,” McEwan says.
When large lumps of uncrushable material are fed into the crushing chamber, the hydraulic pressure increases and a relief valve is activated releasing oil in a controlled manner. This results in the pitman backing away completely and the automatic discharge of uncrushable material. A pressure sensor sends out a signal to stop the feeder and start the hydraulic pump. The discharge gap is automatically returned to the original setting once the hydraulic pressure returns to normal and the uncrushable material has passed. The crusher recovers automatically to normal operation.
“The slag jaw crusher is also suitable for the crushing of other slags such as copper slag, or for the processing of furnace refractory material such as blast furnaces to recover iron,” McEwan says.
IMS Engineering offers technologies for other aspects of ilmenite slag processing. These include Steinert’s overhead suspension magnets for iron and tramp removal and magnetic drums separators which can be used to upgrade discharged material to recover pig iron. Steinert magnetic technology has a proven track record in mines and recycling operations around the world, and is used both to increase the purity of raw materials for further processing and also to protect conveying and processing equipment through tramp iron removal.
In addition, IMS Engineering offers solutions for the further processing of titanium dioxide slag. Kawasaki EarthTechnica Cybas cone crushers or Hazemag hard rock impactors, both suited to the crushing of hard and abrasive material, can be used in a secondary application, followed by Kawasaki EarthTechnica vertical roller mills for the grinding down of material for classification into two fine fractions as raw material for sulphate and chloride pigment processing.