The right speed accumulates only the heavy materials and allows all of the lighter stuff to flow through. This optimum speed is dependent on the size of the gravel you need to move through the system.

Since last year’s articles on explosives for mining, several people have asked for more information about becoming a licensed blaster.

The metal is expensive, not because it is rare but because of the expense to produce and work it. The minerals mined for titanium are all oxides, unlike many base metals that are mostly mined as sulfide minerals.