云南大坪极薄石英脉型金矿开采阶段资源控制方法探讨OA

[Objective]The Daping gold deposit in Yunnan Province is an important and large-scale gold deposit with a long mining history,representing a typical extremely thin quartz vein-type deposit.This paper explores an integrated exploration approach combining trenching and drilling,aiming to assist in the reasonable delineation of ore bodies in this deposit and to provide a reference for the exploration and delineation of similar thin quartz vein-type gold deposits.[Methods]Based on an analysis of ore characteristics and the occurrence state of gold,bulk production-scale tests were conducted on quartz veins and altered wall rocks previously considered to be sulfide-free,demonstrating that their gold content possesses industrial value.Through a combination of exploration and mining comparison,a method is proposed where drilling is used to define the ore-controlling structures,guide trenching operations,and delineate new ore bodies based on bulk sampling analysis from trenches.[Results]For thin vein-type gold deposits,the judgment based on sulfide content should be overcome,taking into account the predominantly intergranular occurrence of gold and the structural ore-control patterns.Pure quartz veins without sulfides and silicified wall rocks should be included as industrial ore bodies.Exploration should adopt a phased combined approach involving sparse drilling control in the early stage and trenching verification in the later stage,with ore-bearing ratios used in resource estimation and evaluation.[Conclusions]Using grades determined by conventional chemical analysis to judge or delineate ore bodies may lead to ore loss.When using drill holes to delineate ore bodies for resource estimation,drill-hole intervals that intersect ore-bearing structures but fail to meet conventional cut-off grades should also be included,with evaluation based on the ore-bearing ratio.This approach provides a more realistic reflection of the deposit.