equipment on a massive scale that m

equipment on a massive scale that makes mining much more efficient. Because increased efficiency means greater profitability, mine operators are always looking to use the most efficient means possible for extracting a mineral deposit. Improved mining techniques have also made it possible to extract lower-grade deposits that were once considered uneconomical.
Similar to other businesses, the profitability of mineral extraction is dependent on the market value of a particular mineral resource and the costs associated with getting it out of the ground and to market. One of the major costs involves removing undesirable rock or sediment called overburden in order to gain access to ma mineral deposit. The problem with overburden is that it requires energy (money) to physically remove it from the earth, plus it must be stored somewhere nearby on the land surface. If the amount of overburden becomes too great, then clearly at some point a mining operation will not be profitable. Another important factor is the concentration or grade of the mineral deposit itself. A higher-grade deposit will enable a mine operator to handle more mine tailings (waste material) and still make a profit. The most desirable situation then would obviously be a high-grade deposit with very little overburden. Other important costs that factor into the economic feasibility of mining include costs associated with transportation, labor, and environmental regulations.
For those who work in the mining industry, an unfortunate aspect has been its long history of so-called boom-and-bust cycles. Fluctuations in the market value of a particular mineral, due to supply and demand changes for example, can make a marginally economic deposit suddenly profitable to mine. Likewise, once-profitable mining operations may be forced to shut down rather abruptly. Because mineral extraction typically requires large amounts of energy prices can have a significant impact on mining operations around the world. As with most industries, higher energy prices means that consumers pay more for mineral-based products, which basically includes anything that cannot be grown.

FIGURE 12.17 Photo shows the trace of a gold-bearing hydrothermal vein that was mined in the late 1800s in Central City, Colorado. Mining began as a surface operation, but later developed into an underground mine as the ore body was followed into the subsurface. Note the piles of mine tailings (waste material) along the trace of the vein.

Surface Mining
Whenever the amount of overburden is such that a mineral deposit is economical to mine, surface-mining techniques are almost invariably chosen over underground mining, because surface mining has lower