摘要
回转窑焙砂中的硫主要以磁黄铁矿形式存在，在高温及酸性气氛下直接水淬冷却时．磁黄铁矿的结构和性质发生了变化．UTA－TG显示水淬焙砂在230℃有一明显的放热峰和失重，XRD表明水淬焙砂中出现α－S的衍射峰，但经过300℃焙烧后则消失．经250－300℃二次焙烧后金的浸出率显著提高．初步研究结果认为磁黄铁矿受酸作用后表层形成了类似于多硫化物（如等）的缺铁性硫化物．由于多硫化物的键能与α－S接近，因而出现α－S（Ss）衍射峰．多硫化物的硫比较活泼，具有较强的反应活性．230℃的反应峰即为该多硫化物的氧化反应引起．
Effects of water quenching on properties of pyrrhotite in calcines of Huangjingdong concentrates are examined using TG-DTA techniques. It is found that for the quenched sample there is an exothendcal peak and weight loss at 230℃. XRD of the sample shows the diffraction peaks of element sulfur. After heating at 300℃ for 2 hours, the diffraction peaks disappear, and gold recovery is increased greatly. It is proposed that polysulfides, such as S2, Sn, Sn are formed during water quenching of calcines at high temperatures. Bond energy of polysulfides is close to that of a -S(S8) and the sulfur in them is very active, which could be oxidized at 230℃.
出处
《有色金属》
CSCD
1998年第4期82-84,81,共4页
Nonferrous Metals
