这项研究调查了在砂浆生产中大规模利用安哥拉铅锌矿的钙质废物(CW)作为骨料的可行性,并最大程度地替代了天然骨料。主要目标是从安哥拉矿山的钙质废物中生产砂浆(细骨料如沙子或更小的混凝土),以在其地下空间进行维护。与混凝土相比,这种流动性更好的迫击炮更容易进入狭窄的空间。此外,它可以用来在矿井周围建造各种建筑。因此,通过替换0%(作为对照样品)制备多个样品,20%,40%,60%,80%,和100%的天然骨料与CW。随后,抗压强度,抗弯强度,吸水,低迷,对这些样品进行了TCLP测试。结果表明,与对照样品和其他样品相比,具有80%CW的砂浆样品在3、14、28和56天表现出明显更高的抗压强度。具体来说,该样品的抗压强度在56天达到35.5MPa,比对照样品增加了18.4%。这表明水泥的水化和C-S-H凝胶的生长得到了增强。对样品的可加工性和坍落度的分析表明,随着CW替代的天然骨料的百分比增加,砂浆的流动性略有下降。除了抗压强度等机械性能外,环境方面,如重金属稳定也非常重要。所以,对四种重金属铅进行了TCLP测试,锌,铜,和镉表明,所有样品中这些元素的释放量均低于EPA标准限值。这些发现证实了砂浆样品中重金属的有效稳定。SEM图像的比较显示,与用80%CW(具有最大压缩强度)制备的样品相比,用20%CW(具有最小压缩强度)制备的砂浆样品在28天后表现出更高的钙矾石存在。
This study investigated the feasibility of large-scale utilizing calcareous wastes (CW) of Angoran lead and zinc mine as aggregates in
mortar production with the maximum possible substitution of natural aggregates. The main goal was to produce
mortar (concrete with fine aggregates as fine as sand or smaller) from Angoran mine\'s calcareous wastes for maintenance in its underground spaces. Compared to concrete, such mortars with better fluidity can enter narrow spaces more easily. In addition, it can be used to build various structures around the mine. Therefore, multiple samples were prepared by replacing 0% (as the control sample), 20%, 40%, 60%, 80%, and 100% of natural aggregates with CW. Subsequently, compressive strength, flexural strength, water absorption, slump, and TCLP tests were conducted on these samples. The results revealed that the
mortar sample with 80% CW exhibited significantly higher compressive strength at 3, 14, 28, and 56 days compared to both the control sample and other samples. Specifically, the compressive strength of this sample reached 35.5 MPa at 56 days, representing an 18.4% increase over the control sample. This indicates that the hydration of cement and the growth of C-S-H gel were enhanced. Analysis of the workability and slump of the samples indicated that as the percentage of natural aggregate replaced by CW increased, the fluidity of the mortar slightly decreased. In addition to mechanical properties like compressive strength, environmental aspects like heavy metal stabilization are also very important. So, TCLP tests conducted on the four heavy metals lead, zinc, copper, and cadmium demonstrated that the released amounts of these elements from all the samples were below the EPA standard limits. These findings confirm the effective stabilization of heavy metals in
mortar samples. A comparison of SEM images revealed that the
mortar sample made with 20% CW (with minimum compressive strength) exhibited a higher presence of ettringite compared to the sample made with 80% CW (with maximum compressive strength) after 28 days.