半合管钻探工艺在滇东南建水普雄稀土矿床勘查中的应用

Application of the split tube core barrel in the exploration of the Puxiong rare earth deposit in Jianshui,southeast Yunnan

滇东南建水普雄稀土矿是一个超大型风化壳离子吸附型稀土矿床,矿体赋存于长岭岗碱性岩体的全风化层和半风化层中。不同于花岗岩风化壳离子吸附型稀土矿,该矿品位高,厚度大,用一般的浅井和赣南钻等取样工程无法揭穿稀土矿体。本文介绍了建水普雄矿区用半合管钻探工艺和浅井工程在相邻位置的施工情况。根据相同的取样层位和样品长度,对比了矿体的品位变化情况,利用品位的相对误差和正负偏差进行了统计,结果表明,单一对应样品品位相对误差合格率为100%;品位<0.07%的正偏差样品占样品总数的78.57%,负偏差样品占样品总数的21.43%;品位≥0.07%的正偏差样品占样品总数的52.17%,负偏差样品占样品总数的47.83%,正负偏差在可控范围内;单工程平均品位相对误差合格率为100%。说明半合管钻探工艺能够有效地应用于风化壳离子吸附型稀土矿勘查,实现资源评价。

The Jianshui Puxiong rare earth deposit in southeast Yunnan is a super⁃large weathered crust ion adsorption rare earth deposit discovered and identified by the No.209 Geological Team,Geological Bureau of Yunnan Nuclear Industry.The ore body occurs in the fully weathered layer and semi⁃weathered layer of the Changlinggang alkaline rock body.The ore has high grade and large thickness which is different from the ion⁃adsorbed rare earth ore in the weathered granite crust;thus,conventional shallow wells and the Gannan drills cannot be used to expose the rare earth ore body.In this paper,the split tube core barrel and the construction of shallow wells in adjacent locations are used to compare the grade changes of the ore body in the Jianshui Puxiong mining area for the same sampling layer and sample length with calculation of the relative error,and positive and negative deviation of the grade.The results show that the relative error qualification rate of a single corresponding sample is 100%;the samples with grade positive deviation <0.07% account for 78.57% of the total number of samples,while those with grade negative deviation account for21.43% of the total number of samples. The samples with grade positive deviation ≥0.07% account for samples52.17% of the total,while those with negative deviation account for 47.83% of the total number of samples,indicatingpositive and negative deviations within the controllable range. The single project average grade relative errorqualification rate is 100%. It shows that the split tube core barrel can be effectively applied to the exploration ofweathered crust ion⁃adsorbed rare⁃earth minerals to realize resource evaluation.