What type of drill do hard rock miners use?

In general, hard rock miners use top hammer drills for holes less than 4 inches (150mm) in diameter, and ITH drills for larger holes. Miners still use blade bits (chisel or cross) for drilling small diameter blastholes in hard rock; button bits are normally more economical in the larger diameters.

How do Arctic mines drill?

One arctic mine employs dry drilling underground. Efforts to duplicate the system elsewhere have so far been thwarted, mainly because of silica content in the ore. The V-cut, also called “wedge,” “cone,” and “pyramid,” is typically drilled at an inclination of 30 degrees from the drive axis.

Can you fill a mine with rock?

Some of the larger mines in the USA quarried rock and dropped it down fill raises to the mine workings. Filling with rock alone is seldom practiced today except for filling tertiary stopes. CRF originally consisted of spraying cement slurry or CHF on top of stopes filled with waste rock (Geco and Mount Isa).

What are mining rules of thumb?

Rules of thumb and comparable data are often sufficient to provide immediate, approximate answers to kick-start the problem solving process. Consequently, mining industry experts initially compiled and published many rules of thumb, which we delivered at mining conventions across North America.

What is a control chart in hard rock mining?

The control chart is the most important of the statistical tools. A control chart is simply a run chart with statistically determined upper and lower limits (drawn on either side of the process average). Lb. Lb. Following is a list of suggested reference texts for a hard rock mining technical library.

How has the mining industry responded to the hard rock miner's Handbook?

Mining industry response to the book continues to be incredible. Thanks in large part to the efforts by John Chadwick of the Mining Journal, , and many other members of the mining community, the Hard Rock Miner’s Handbook has been distributed to over 113 countries worldwide.