Peculiarities of drilling and blasting in underground small-scale mines

Abstract Artisanal and Small-scale Mining (ASM) is a prominent activity in the extractive industry: considering only gold, it produces about 20% of the world market supply. Despite this fact, ASM is generally associated with the negative aspects of its environ mental impact, and operational research is generally neglected. This article empha sizes the peculiarity of the drilling and blasting systems of small underground mines in selected South American Countries. Such Countries, while having large mineral deposits and well recognized large-scale mining activities, at the same time still pres ent on their territory ASM activities that are archaic, highly inefficient and dangerous for the safety of its operators. This article documents drilling and blasting activities from gold mining in Ecuador and Chile. First, described are the outdated and often non-rational techniques employed by miners, to provide a general framework of the current methods. Then, shown is what can be improved and how the current methods can be modified. Finally, some field applications and the comparisons of the results ob tained are presented. One case shows how blast pull efficiency can be increased from 82% to 98% by changing non-rational applications of explosive products to rational, scientific-based employment. Another case shows how, by rationalizing blast designs, drilling and blasting costs can be reduced by 9% per month, the advance by blasting increased by 29% and the pull efficiency increased from 70% to 90%. Finally, it is concluded that examples of application show how operational improvements are eas ily applicable in the field, relying only on tools and resources of artisanal mining, but combining solid engineering bases with confidence-gain and respect for the experience of the miners.摘要：手工与小规模采矿（Artisanal and Small-scale Mining，ASM）是采矿业中的重要活动类型——仅以黄金品类计算，其产量约占全球市场总供应量的20%。尽管贡献如此显著，ASM往往仅被等同于其负面环境影响，且相关作业研究长期遭到忽视。本文聚焦南美部分国家小型地下矿山的钻孔与爆破系统的特殊性。这些国家虽拥有大型矿产储量且具备成熟的大规模采矿产业，但其境内仍存在老旧低效、作业人员安全隐患突出的手工与小规模采矿活动。本文记录了厄瓜多尔与智利的黄金采矿钻孔与爆破作业流程：首先，详细阐述矿工所采用的过时且常不合理的作业技术，以梳理当前作业方法的整体框架；随后，分析可优化的方向及现有方法的改进路径；最后展示若干现场应用案例并对比其所得结果。其中一则案例表明，将不合理的爆破器材使用方式调整为科学规范的应用模式，可将爆破采掘效率从82%提升至98%；另一则案例显示，通过优化爆破设计，钻孔与爆破成本每月可降低9%，爆破进尺提升29%，且爆破采掘效率从70%提升至90%。本文最终得出结论：实践案例证实，仅依托手工采矿现有工具与资源，结合扎实的工程学基础，同时尊重矿工的实操经验，即可轻松实现现场作业优化，并有效提升作业可靠性。