The Mechanical and Physical Characteristics of Steel Dust Bricks
S. O. Adeosun *
Department of Metallurgical and Materials Engineering, University of Lagos, Nigeria.
O. I. Sekunowo
Department of Metallurgical and Materials Engineering, University of Lagos, Nigeria.
O. P. Gbenebor
Department of Metallurgical and Materials Engineering, University of Lagos, Nigeria.
F. Orowho
Department of Metallurgical and Materials Engineering, University of Lagos, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
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.
Keywords: Steel-dust, brick, sintering, thermal properties, wear resistance