普雷米尔（Premier）矿位于南非比勒陀利亚市东38km，是目前世界上最大的管状钻石矿。矿体理深380m，被75m厚的倾斜辉长岩分开。矿山于1903年投产，首先用露天开采，后转入地下开采。地下开采初期，试验采用空场法，因辉长岩和不稳固的角砾云橄岩（金伯利岩）过早崩落，引起支 The Premier mine, located 38km east of Pretoria, South Africa, is currently the largest tubular diamond mine in the world. The ore body is 380 m deep and separated by a 75-m thick gabbro. The mine was put into operation in 1903, first with open-pit mining and later underground mining. In the early stage of underground mining, the experiment used an empty-field method. Premature caving of gabbro and unstable brecciated peridotite (kimberlite) caused the branch