Ilmenite EARS process

EARS [Enhanced acid regeneration system] A process for recovering hydrochloric acid from the ERMS ilmenite beneficiation process. It may be used also for recovering waste pickle liquor. The acid liquor containing ferrous chloride is evaporated at low temperature to form iron chloride pellets, which are fed to a pyrohydrolysis reactor. This generates hydrochloric acid and iron oxide pellets, which can be used for steel production or disposed of as inert landfill. Developed by E. A. Walpole at the University of Newcastle, Australia, from the early 1990s and piloted by Austpac Gold (now Austpac Resources). 

In a process variant (Enhanced Acid Regeneration System EARS process), the ilmenite is roasted to convert the titanium component into the insoluble rutile form and to condition the iron component for leaching. The product is then rapidly leached at atmospheric pressure in hydrochloric acid to remove the iron, leaving rutile crystals in the former ilmenite grain. This synthetic rutile (typically 96-98% Ti02) is then washed, filtered, and calcined. The iron chloride leach liquors are processed to regenerate the acid, and the iron oxide pellets can be sold for use by the steel or cement industries. 

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