Pacific Resources Research Center, University of the Pacific, Stockton, CA 95211, USA.
J Hazard Mater. 2012 Apr 30;213-214:71-82. doi: 10.1016/j.jhazmat.2012.01.059. Epub 2012 Jan 24.
In this paper, a systematic study was conducted to investigate a novel silica alumina-based backfill material composed of coal refuse and fly ash. The coal refuse and fly ash had different properties under various thermal activation temperatures (20 °C, 150 °C, 350 °C, 550 °C, 750 °C and 950 °C). It is known that a thermal activation temperature ranging from 20 °C to 950 °C significantly increases the flowability and pozzolanic properties of the coal refuse; however, the flowability of fly ash decreases when the activation temperature is higher than 550 °C because of a severe agglomeration phenomenon on its surface. An optimal design for this backfill material was determined to include an activated portion composed of 5% coal refuse at 750 °C and 15% fly ash at 20 °C. This combination yields the best performance with excellent flowability, a high compressive strength and a low bleeding rate. The microanalysis results corresponded well with the performance tests at different activation conditions. In the coal refuse, kaolinite peaks began to decrease because of their transformation into metakaolin at 550 °C. Chlorite peaks disappeared at 750 °C. Muscovite peaks decreased at 750 °C and disappeared at 950 °C. During this process, muscovite 2M(1) gradually dehydroxylated to muscovite HT. Furthermore, this paper examined the environmental acceptance and economic feasibility of this technology and found that this silica alumina-based backfill material composed of coal refuse and fly ash not only meets EPA requirements but also has several advantages in industry feasibility when compared with hydraulic backfill, rock backfill and paste backfill.
在本文中，我们对一种由煤矸石和粉煤灰组成的新型硅铝基充填材料进行了系统研究。煤矸石和粉煤灰在不同的热活化温度（20°C、150°C、350°C、550°C、750°C 和 950°C）下具有不同的性质。已知，热活化温度在 20°C 至 950°C 之间显著提高了煤矸石的流动性和火山灰性能；然而，当活化温度高于 550°C 时，粉煤灰的流动性会降低，因为其表面会发生严重的团聚现象。确定了这种充填材料的最佳设计方案，包括在 750°C 下使用 5%的煤矸石和在 20°C 下使用 15%的粉煤灰作为活性部分。这种组合具有最佳的性能，表现出良好的流动性、较高的抗压强度和较低的泌水率。微观分析结果与不同活化条件下的性能测试结果吻合良好。在煤矸石中，高岭石峰由于在 550°C 时转化为偏高岭土而开始减少。绿泥石峰在 750°C 时消失。白云母峰在 750°C 时减少，在 950°C 时消失。在此过程中，白云母 2M(1) 逐渐去羟基化生成白云母 HT。此外，本文还考察了该技术的环境可接受性和经济可行性，发现这种由煤矸石和粉煤灰组成的硅铝基充填材料不仅符合 EPA 要求，而且在工业可行性方面与水力充填、岩石充填和膏体充填相比具有几个优势。
