硫化物氧化对充填体长期强度的影响

Long-term deterioration of cemented paste backfill due to sulphide oxidation

尾砂胶结充填体的长期强度与所用尾砂中硫化物的活性有关。有色金属矿选矿产生的尾砂中一般均含有较高的硫化物,硫化物与空气和水接触后会发生氧化反应生成硫酸盐,从内部形成对充填体的硫酸盐侵蚀。当胶结充填体具有较高的饱和度时,尾砂中的硫化物氧化反应受到一定程度的抑制,充填体长期强度的衰减可能会有一定程度的减轻。

Cemented paste backfill （CPB） mining is used worldwide and the long-term strength of the CPB is affected by the oxidation of sulphides contained in tailing sand material. It is found that the sulphide oxidation product, sulphate, reacts with the hydrated product of cement, leading to the formation of expansive phases such as gypsum and ettringite, which are responsible for the long-term decrease in strength of CPB. A higher saturation seems to reduce the strength attenuation of CPB.