نوع فایل: power point قابل ویرایش 27 اسلاید قسمتی از اسلایدها: Performance of roadheader The roadheader production rate and bit costs are controlled by several parameters including: Rock parameters, such as rock compressive and tensile strength, percent of hard and abrasive mineral content ( i.e. quartz), rock fabric and matrix type, and elastic behavior of rock material etc. Ground condition, such as degree of fracture (RQD), ...