Adeleke A A, Odusote J K, Lasode O A, Ikubanni P P, Malathi M, Paswan D
Department of Mechanical Engineering, University of Ilorin, Ilorin, Nigeria.
Department of Materials and Metallurgical Engineering, University of Ilorin, Ilorin, Nigeria.
Heliyon. 2019 Jul 25;5(7):e02160. doi: 10.1016/j.heliyon.2019.e02160. eCollection 2019 Jul.
Coal processing industries generate millions of tons of fines (<3 mm) during mining operation and are often considered as wastes. These wastes have enormous potential in serving as energy and metallurgical operation feedstock. One avenue for its use is densification into briquettes or pelletizes. Various briquetting techniques have been adopted in the past few decades; however, the main issues upfront in commercializing these techniques are significant binder cost and poor mechanical integrity. Therefore, the present study concentrates on utilizing commonly available organic binder along with pretreated biomass in developing coal fine briquettes. Briquettes were produced after initial pretreatment of the raw materials under a load of 2 tons. Briquettes were cured in an inert environment and eventually characterized for its main litmus requirements (physical properties). It was observed that pitch-molasses bonded briquettes have better physical properties leading to good mechanical integrity than briquettes produced from individual binder. The proximate, ultimate and calorific value analyses of the briquettes do not deteriorate but mildly improved compared to the raw coal fines. With a density of 1.18-1.32 g/cm, drop to fracture that is greater than 100 (times/2 m), impact resistance index well above 6000, water resistance index of 99% and cold crushing strength of 9 MPa, pitch-molasses bonded briquettes clearly surpassed recommended physical properties benchmarked for briquettes of industrial and domestic end use. The physical properties of the briquettes favorably meet requirements as feedstock for rotary kiln direct reduced iron and COREX iron-making processes as well as fuel for thermal operations.
煤炭加工行业在采矿作业过程中会产生数百万吨细煤（<3毫米），这些细煤通常被视为废弃物。这些废弃物在用作能源和冶金作业原料方面具有巨大潜力。其一种利用途径是将其致密化为煤球或球团。在过去几十年中已采用了各种压块技术；然而，将这些技术商业化面临的主要前期问题是粘结剂成本高昂且机械完整性差。因此，本研究专注于利用常见的有机粘结剂以及经过预处理的生物质来开发细煤煤球。在2吨负载下对原材料进行初步预处理后制作煤球。煤球在惰性环境中固化，最终对其主要的基本要求（物理性能）进行表征。观察到，与由单一粘结剂制成的煤球相比，沥青 - 糖蜜粘结的煤球具有更好的物理性能，从而具有良好的机械完整性。与原煤细粉相比，煤球的近似分析、元素分析和热值分析并未恶化，反而略有改善。沥青 - 糖蜜粘结的煤球密度为1.18 - 1.32克/立方厘米，2米下落破碎次数大于100次，抗冲击指数远高于6000，耐水性指数为99%，冷压强度为9兆帕，明显超过了工业和家庭最终用途煤球推荐的物理性能基准。煤球的物理性能完全符合回转窑直接还原铁和COREX炼铁工艺原料以及热加工燃料的要求。
