Molasses and air blown coal tar pitch binders for the production of metallurgical quality formed coke from anthracite fines or coke breeze

Abstract

The effect of the type and the amount of hardeners, such as ammonium nitrate, ammonium carbonate and nitric acid on the molasses bonded briquettes prepared from anthracite fines or coke breeze were investigated. Amongst the hardener studied the best results were obtained with 2.5% ammonium nitrate hardener. The briquettes produced with this hardener were highly water resistant but not waterproof and their tensile strengths were not adequate to be used as a substitute for the metallurgical coke. Therefore, the briquettes were prepared with molasses containing 2.5% ammonium nitrate hardener and air blown coal tar pitch blended binder. When the blended binder was used for the production of anthracite fines or coke breeze briquettes, after curing at 200°C for 2h, they became waterproof and their tensile strengths were found to be sufficient to be used as a substitute for coke oven coke. The briquettes after curing could be directly charged into the blast furnace without carbonizing them at high carbonization temperatures. Since molasses and coal tar pitch, are relatively cheap and readily available materials, the process investigated could be economical way of producing high quality formed coke.