In allusion to the defects of large material consumption and high construction cost of conventional artificial boundary pillar for the transition from open pit to underground mining. a new multi-function type of artificial boundary pillar scheme of reinforced concrete is proposed. which creates favourable conditions for underground mining below the pillar and stacking tailings over th... https://www.roneverhart.com/AMS-Neve-1073SPX-Single-Preamp-and-EQ-p33827/