钼尾矿粉作为水泥基材料掺合料的适用性研究

Applicability of molybdenum tailings powder as admixture of cement-based materials

为了解决钼尾矿资源化利用的问题,以黑龙江伊春鹿鸣矿业的钼尾矿为原材料制备了磨细钼尾矿粉。通过标准稠度用水量、凝结时间、流动性、强度、活性指数、微观结构及水化产物等性能指标,研究了钼尾矿粉作为掺合料对水泥基材料工作性能、力学强度和微观结构的影响。研究结果表明:钼尾矿粉的掺入使水泥的标准稠度用水量增大了3.2%,初凝时间和终凝时间分别延长了75%和93%;且钼尾矿粉的掺入降低了砂浆流动度,增大了砂浆需水量比,降低了砂浆60 min流动度经时变化;随着钼尾矿粉取代率增加,砂浆的抗折强度、抗压强度、活性指数均逐渐降低,但砂浆7 d、28 d活性指数均大于60%;当钼尾矿粉取代率为30%时,净浆微观结构存在较少孔隙,但内部结构较为致密,且净浆中除钙矾石、氢氧化钙等水化产物,还含有SiO_(2)、长石、云母等钼尾矿粉中矿物。实验结果可为钼尾矿作为水泥基材料掺合料提供基础性实验数据。

In order to solve the problem of resource utilization of molybdenum tailings,molybdenum tailings powder is prepared from molybdenum tailings of Yichun Luming Mining.The influence of molybdenum tailings powder as admixture on the working performance,mechanical strength and microstructure of cement-based materials is studied through the performance indexes of standard consistency water consumption,setting time,fluidity,strength,activity index,microstructure and hydration products.The results show that the addition of molybdenum tailings powder increases the standard consistency water consumption by 3.2%,and the initial setting time and final setting time are prolonged by 75%and 93%respectively.The addition of molybdenum tailings powder reduces the fluidity of mortar,increases the water demand ratio of mortar and reduces the 60 min in fluidity of mortar over time.With the increase of molybdenum tailings powder replacement rate,the flexural strength,compressive strength and activity index of mortar decrease gradually,but the activity index of mortar at 7 d and 28 d is more than 60%.When the replacement rate of molybdenum tailings powder is 30%,the microstructure of the paste has less pores,but the internal structure is denser.Besides hydration products such as ettringite and calcium hydroxide,the paste also contains minerals in molybdenum tailings powder such as SiO_(2),feldspar and mica.The test results can provide basic test data for molybdenum tailings as admixture of cement-based materials.