The Mechanical and Physical Characteristics of Steel Dust Bricks

This work investigates thermal and mechanical properties of bricks produced from particles of electric arc furnace (EAF) hazardous fumes with a view to enhancing safe disposal and reduce the current prohibitive cost of handling. Test samples are prepared from the as-received steel-dust and sieved to 53-106 µm size range, mixed with 10-35 wt% bentonite content and rammed in a cylindrical mould. The samples are first allowed to cool in air at ambient temperature (32ºC) for 24 hours and then heated in a muffle furnace at 6.7ºC per minute to sinter at 1000ºC with 10-60 minutes. Relevant refractory property tests of the steel-dust bricks namely; bulk density, porosity, cold crushing strength (CCS), refractoriness, linear shrinkage and wear resistance are carried out and their results analyzed. Based on their performance ratings, the EAF steel-dust brick containing 15wt% bentonite and held for 30 minutes during sintering possess the highest ranking of 4.2/5.0 while bricks with 25,30 and 35 wt% bentonite at 50, 60 and 40 minutes holding time respectively exhibit 3.8/5.0 ranking. The refractory properties of the bricks are significantly influenced by the combination of the proportion of fine particle size (106µm), amount of bentonite added and the sintering holding time. Steel-dust bricks can be useful as thermal insulator in non-ferrous reactors and allied devices.