ил уурхайн тээвэр үнэ авах & precio. Jul 01, 2012· Surface mining operation units: Drilling and Blasting / Ил уурхайн процессууд: Өрөмдлөг, тэсэлгээ Drilling The term drilling is used for smaller diameter holes, with a few exceptions such as shaft drilling and raise drilling, where larger excavations are created by special machines ...