Alluvial Chromite Separation

Application Description

The Continuous Variable Discharge concentrator (CVD) has been successfully applied in the separation of Alluvial Chromite. Chromite has a specific gravity of 4.6 against a background gangue gravity of approximately 2.7. The CVD is used as a rougher in this application and maximizes chromite recovery and minimizes mass pull to concentrate.

Historically, alluvial chromite has been separated in large spiral concentrator plants. A CVD coupled with a Mozley MGS has proven to produce superior metallurgical performance over much larger spiral plants.

Benefits

• Superior metallurgical performance over existing gravity plants
• Small size to facilitate mobility when necessary
• Ability to process ores with high clay/slimes content
• Low operating cost

Application

Alluvial chromite can be separated in an all-gravity flowsheet with a CVD. Run of mine feed is washed and screened to minus 1.5mm and fed to the CVD. The CVD produces a chromite concentrate that's sent to final upgrading in a spiral separator. The CVD treats fresh feed and a circulating load of tails from the spirals that is classified in a hydrocyclone. The gravity circuit shown depicts a CVD concentrator as the primary unit operation, achieves recoveries in excess of 90% with saleable chromite grades of 45%.