MATHEMATICAL OPTIMIZATION OF NON-COKING COAL INCLUSION IN COKING BLEND FORMULATIONS

Blend formulation to maximize the inclusion of non-coking coals with the scarce and expensivecoking coals is an essential practice in the steel industry. This study demonstrated the use ofMicrosoft Excel based on a blending model to obtain probable cokeable blends between sampleprime coking coals and non-coking Nigerian Lafia-Obi and Okaba coals; having high ash/sulphurand high volatile, respectively. The results obtained showed that optimal binary, ternary andquaternary probable cokeable blends are possible. A cokeable binary blend of 64.51% low volatile,high vitrinite reflecting Western Canada prime coking coal and 35.49% Okaba coal with a costreduction per ton of $61.56 was obtained. Also, a ternary blend of 74.04% medium volatile primecoking UK Ogmore coal produced an optimal cokeable blend including 19.22 and 6.74 percents ofLafiia-Obi concentrate and Okaba (as-received); respectively with a saving in cost per ton of$39.05. Furthermore, a quaternary blend comprising 40.35, 23.17, 23.17 and 13.30 percents oflow volatile Canada, medium volatile Ogmore, Lafiia-Obi concentrate and Okaba (as-received);respectively with a saving in cost per ton of $56.06 was realized. The results obtained showed thatvitrinite reflectance, coal beneficiation to reduce ash and sulphur contents and the use of a highvolatile coal as a blend component are critical factors in obtaining probable cokeable blends. If thelowest cost binary blend proves cokeable in confirmatory tests, the significant cost reduction ofabout 29.31% achievable will make cokemaking more economical and sustainable.