Mining is the act of removing minerals from the ground. Depending on where those minerals are located and the ease in which they can be extracted, there are different mining methods used. Two of the most commonly understood are placer and hard rock. They are both very distinctly different ways to remove ore.
Here is a look at each:
The word placer translates to mean ‘sand bank’ in Spanish and hints at this method of mining. Gold rushes began and ended with placer mining because it is probably the easiest way for anyone to mine and in recent decades, pick up as a hobby. Placer mining is a method of mining that focuses on the recovery of minerals located on or close to the surface of the ground. In other words, if you are driving a mine shaft or blasting hillsides with dynamite you are not placer mining.
Placer mining can be done by hand panning in a stream. Other popular ways to placer mine include dredging, using a sluice box or rocker. Sometimes minerals are just sitting on the surface waiting to be picked up. This is exactly what happened in the late 1800’s that launched gold rushes in California and Western Canada. In most cases it was gold nuggets glistening in a brook that attracted the attention of early miners and led to the development of many communities.
Hard Rock Mining
As the name indicates, mining into hard (solid) rock in order to locate and remove raw minerals (ore) with tools and equipment describes this mining method. Tools usually used to achieve this include rock drills, dynamite, heavy excavating equipment and even shovels or picks. Shafts inserted vertically into ground allowed miners a means to follow an ore body or a vein. Tunnels may be added from the shaft(s) to run horizontally.
Shafts and tunnels typically use a wood head frame to keep them from collapsing with lighting strung into them for visibility. Depending on how far underground the shafts and tunnel go, some may flood with rising ground water which results in either the use of pumps to remove the water or abandonment of the area for more promising locations. Hard rock mining is a more expensive way to mine and is usually the way in which a mining company would extract minerals.
The Connections Between Placer and Hard Rock Mining
Although placer mining is more of a small scale individual (often recreational in today’s world) type of mining, several larger commercial hard rock mining operations originated through placer mining. This is particularly true of mines that have history that can be traced back to early miners hand panning or dredging over a hundred years ago. Many of the rivers and streams located in historic gold rush areas of North America have claims staked on them to this day. These placer miners work their claims annually with a few being sold to small mining companies looking for hard rock mining opportunities.