Apparent activation energy for spontaneous combustion of sulfide concentrates in storage yard

来源期刊：中国有色金属学报(英文版)2011年第2期

论文作者：阳富强 吴超 崔燕 陆广

文章页码：395 - 3401

关键词：表观活化能；硫精矿；自燃；热重分析；差示扫描量热法

Key words：apparent activation energy; sulfide concentrates; spontaneous combustion; thermogravimetry (TG) analysis; differential scanning calorimetry (DSC)

摘    要：为了判定储存在矿仓内的硫精矿是否存在自燃危险性，从冬瓜山铜矿矿仓采集了不同类型的3种矿样(高硫精矿、硫铁精矿、硫铜精矿)。利用同步TG-DTG-DSC分析技术对3种矿样在升温速率分别为5、10、15、20和 25 ℃/min的条件下，在空气气氛中的化学反应过程进行深入研究。利用DTG曲线上的峰值温度，将每种矿样的反应过程划分为不同阶段，基于Ozawa-Flynn-Wall方法求得相应区间的表观活化能。结果表明：每种矿样的反应过程相当复杂，求得的表观活化能随着反应温度区间的不同而发生改变，从室温到800 ℃，3种矿样在各个反应阶段的活化能为36~160 kJ/mol；高硫精矿与硫铁精矿在150 ℃以下的表观活化能较铜精矿的低，因此在室温条件下高硫精矿与硫铁精矿更容易引发自燃。

Abstract: In order to evaluate the spontaneous combustion hazard of sulfide concentrates in storage, three different kinds of sulfide concentrates (sulfur-rich sulfide concentrate, iron sulfide concentrate and copper sulfide concentrate) were obtained from a storage yard in Dongguashan Copper Mine, China. The reaction processes at different heating rates of 5, 10, 15, 20, and 25 °C/min in air flow from ambient temperature to 1 000 °C were studied by TG-DTG-DSC analysis. By the peak temperatures of DTG curves, the whole reaction process for each sample was divided into different stages, and the corresponding apparent activation energies were calculated by the Ozawa-Flynn-Wall method. It is found that the reaction process of each sample is considerably complex; the apparent activation energy values change from 36 to 160 kJ/mol in different temperature ranges; sulfur-rich sulfide and iron sulfide concentrates have lower apparent activation energy than copper sulfide concentrate below 150 °C; so they are more inclined to cause spontaneous combustion at ambient temperature.