空气反循环取样钻探技术应用于金矿勘查的地质效果对比研究

Comparative study on geological effect of air reverse circulation sampling drilling technology in gold exploration

摘要:

长期以来，由于地质方面对岩样认知的限制，空气反循环取样钻探技术（RC工艺）在我国矿产勘查中的应用并不广泛。本文根据RC工艺在云南鹤庆北衙金矿等矿区的试验情况，从找矿地质效果对比分析角度提出了一些认识。首先明确了此次RC工艺与常规岩心钻进工艺对比示范性应用试验的目的及试验内容；介绍了试验孔选取依据；从岩样收集与采样方法、岩样采取率、地层与矿层丢失情况、岩样获取地层的岩性及原生结构、推算岩层产状方面的准确性、岩心污染程度、计算矿品位的准确性等7个方面对比分析了RC工艺与常规岩心钻进工艺应用于金矿勘查的地质找矿效果；认为RC工艺具高效、低成本等施工优势，且在岩样代表性、岩心污染、矿品位等找矿效果方面优于常规岩心钻进。最后进一步指出了RC工艺目前应用于矿产勘查仍存在的一些问题，并提出相关建议。

关键词:空气反循环取样钻探;常规岩心;RC岩样;金矿勘查;取样工艺;钻进效率;地质效果

Abstract:

Air reverse circulation sampling drilling technology has not been widely used in mineral exploration for a long time due to the low recognition of rock samples by domestic geologists. In view of the test of air reverse circulation drilling technology in Beiya Gold Mine， Heqing， Yunnan Province， this paper puts forward some findings through comparative analysis of the geological effect in mineral exploration. This paper defines the purpose and contents of the demonstration application test of air reverse circulation sampling technology and conventional core drilling technology； introduces the basis for test hole selection； and compares and analyzes the geological effect of the RC sampling method and the conventional core drilling method in gold exploration from seven aspects： rock sample collection and sampling method， rock sample recovery， missing of strata and ore beds， lithology and primary structure of the sampled strata， accuracy of rock occurrence calculation， core pollution degree， and accuracy of ore grade calculation. The study reveals that the RC sampling method has high efficiency and low cost； and it is superior to conventional core drilling in terms of rock sample representativeness， core pollution and ore grade. Finally， some problems in the application of RC technology in mineral exploration are further pointed out， and the relevant suggestions are put forward.

Key words:air reverse circulation sampling drilling;conventional core;RC rock sample;gold exploration;sampling technology;drilling efficiency;geological effect