ABSTRACT

Porous, granular or fibrous materials that contain oxidizable organic constituents often experience self-heating that leads to spontaneous combustion. Activated carbon is known to be prone to self-heating because of its high surface area. Experiments were conducted to identify factors likely to cause self-heating of materials for producing activated carbon. Spontaneous combustion and characterization tests were carried out on three materials generated from the South African Coalfields [coal slurry (SLY), coal discard (DIS) and run-of-mine fines (ROM)]. This study indicated that the higher amount of vitrinite and lower ash contents in sample ROM compared with the other two samples SLY (3.73) and DIS (3.72) could be the cause of its higher liability value (3.8). The potential of activated carbons produced from the material most liable for spontaneous combustion was also investigated. The activated carbons were prepared by KOH activation, and the results obtained indicated that the activated carbons can be used in several applications. The synthesized activated carbons were characterized by nitrogen adsorption isotherms and SEM characterization. Surface area exceeding 1000 m²/g was obtained for most of the activated carbons produced. The nitrogen isotherms and pore size distribution profiles confirm highly porous activated carbons consisting of micropores and mesopores.

摘要

含有可氧化有机成分的多孔、粒状或纤维状材料通常会发生自热，从而导致自燃。众所周知，活性炭因其高表面积而易于自热。进行了实验以确定可能导致生产活性炭的材料自热的因素。对南非煤田产生的三种材料 [煤浆 (SLY)、弃煤 (DIS) 和原矿细粉 (ROM)] 进行了自燃和表征测试。该研究表明，与其他两个样品 SLY (3.73) 和 DIS (3.72) 相比，样品 ROM 中较高的镜质体含量和较低的灰分含量可能是其较高的责任值 (3.8) 的原因。还研究了由最容易自燃的材料生产的活性炭的潜力。通过KOH活化制备活性炭，所得结果表明活性炭可用于多种应用。合成的活性炭通过氮吸附等温线和 SEM 表征进行表征。表面积超过 1000 m对于生产的大多数活性炭，获得了^{2 /g。}氮等温线和​​孔径分布曲线证实了由微孔和中孔组成的高度多孔活性炭。