Recovery of ferrochrome values from flue dust generated in ferroalloy production – a case study

Abstract

Ferrochrome is usually produced by the reduction of chromite ore in a submerged arc or direct current furnace. The production process generates a large quantity of flue dust that contains potentially valuable components, such as ferrochrome, iron and carbides. In many instances, valuable chromite minerals are misplaced in the flue dust along with the slag forming minerals during the reduction process. In the present investigation, mineral beneficiation techniques were used to recover the ferrochrome material in lieu of the pyro-and hydrometallurgical techniques, which are currently being practiced. The experimental results show that gravity concentration could enrich Cr values in the concentrate to 42?2% with 37?3% yield from flue dust material containing 37?3%Cr. The beneficiation techniques could only marginally enrich the ferrochrome values because of the complex association of the metallic phase with the slag forming phases.

Chromium Concentrate Recovery from Solid Tannery Waste in a Thermal Process

“…Low-grade chromite ore has to be treated to increase the Cr content prior to subjecting to the smelting process, e.g., by carbochlorination [54]. The addition of Cr-enriched substances, such as the ash obtained in the presented research, to lean and complex ores or to other Cr-containing substrates (such as flue dust from ferrochrome production [55]) could allow for greater resource efficiency and higher recovery rates [56]. The possibility to produce ferrochrome from TS roasted at 650 • C and mill scale waste in an aluminothermic process was investigated by Wcisło et al [57] on a laboratory scale, with positive results.…”