Briquetting and Remelting of Aspiration Dust Generated During High-Carbon Ferrochrome Crushing in Direct Current Electric Arc Furnaces

TL;DR

This study presents a method to recycle dust from high-carbon ferrochrome crushing by making strong briquettes for efficient remelting.

Contribution

A novel briquetting technology using aspiration dust and gas-cleaning dust with a polymer binder for remelting in DC EAFs.

Findings

Briquettes showed high mechanical strength (195 kg splitting strength, 98% drop resistance).

Chromium recovery reached 94%, 3–4% higher than with loose dust.

Electric energy consumption was reduced by 29% compared to traditional methods.

Abstract

This study addresses the problem of efficient utilization of aspiration dust (AD) generated during crushing of high-carbon ferrochrome (HCFeCr). To solve this issue, a briquetting technology was proposed, involving aspiration dust blended with dry gas-cleaning dust (20 wt.% as filler) and an organic polymer binder (3 wt.%). The produced briquettes demonstrated high mechanical strength (average 195 kg per briquette in splitting strength and 98% drop resistance), ensuring maximum integrity during transportation and handling. Pilot-industrial remelting of 35 tons of briquettes in a 1.8 MVA direct current electric arc furnace (DC EAF) confirmed the effectiveness of the proposed technology for HCFeCr production. Chromium recovery into the alloy reached 94%, which is 3–4% higher compared to remelting of loose dust. The specific electric energy consumption was 1600 kWh/t, representing a 29% reduction compared to loose dust processing. The produced metal met commercial grades FeCr800–FeCr900 specifications. Additional advantages included elimination of dust formation, reduction in fines generation during crushing of the final metal to 15%, and improved environmental performance. The developed technology represents an economically and environmentally viable solution for comprehensive recycling of ferroalloy dust waste.

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