GOLD MININGMining operations are usually carried out in the process of four different phases that consist of prospecting or in what is known as the search for deposits of minerals, in the exploration, or the work that has to do with assessing the size, shape, location, and economic value of the deposit, in the development, or the work of setting up admission to the deposit so that the minerals can be extracted from it and from exploitation, which is the work of extracting the minerals.
In the past, ore bodies used to be found by prospectors in areas where veins were exposed on the surface, or by pure chance, just like when gold was discovered in California in 1848. These days, nonetheless, prospecting and exploration are skillful professions that are directly liked and involved with specialist scientific workforce.
Teams of geologists, mining engineers, geophysicists, and geochemists work jointly in order to locate new deposits. Some of the modern prospecting methods have to do with regional geological studies to delineate areas where mineralization is likely to have taken place; extensive surveys by refined tools mounted in airplanes and artificial earth satellites in order to find any irregularities in the magnetic field of the ground, electrical fields, or radiation patterns in order to identify the most potential locations, visual assessments and inspections are also done of the surface area for coloring, rock formations, and plant life, chemical examinations of soil and water in the area, and surface work with geophysical instruments.
These modern methods are able to show the deep seated as well as near surface prospects, and they can be used as a basis for introduction estimates of the economic probability of the prospect. The following exploration work has to do with digging pits, sinking exploration shafts, and core drilling operations, all of which are inclined to classify the physical restrictions of the ore body and allow a more dependable estimate of its economic value. The findings might utter the technique used to reach the ore body, the degree of the development work, and the best way of exploitation.
The choice to develop an ore body can be decided on as soon as enough information is given to show a beneficial return on the financial investment. Total certainty about the full potential of the mineral is not essential at this point; exploration work can keep on going over a lot of years although the deposit is being mined.
After the decision has been made to mine an ore deposit, the means of entry and the amount of lateral or subsidiary development needs to be decided on. If the ore body is at or is close to the surface and goes to a depth of no more than a few hundred feet, it might be developed by an open pit excavation, by using power shovels and large trucks. If, nonetheless, it is deep or steeply inclined, entrée may possibly take place through a vertical or inclined shaft, an adit, or crosscut tunnels. The topography of the region, the geometry and physical nature of the ore body, and the projected technique of exploitation have an importance on this decision. In cases where the terrain is practically flat, entry needs to be made through a shaft. In mountainous areas, access to the ore body might be obtained through an adit, an almost straight tunnel from which crosscuts may be driven at right angles to reach the ore. Shaft sinking involves a bigger outlay of capital and higher operating costs than an adit or crosscut opening. A shaft has the need of hoisting equipment to lift the ore and rock to the surface, pumping equipment to get rid of any water present and structural support for the rock and the mechanical equipment operating in the shaft. In an adit, drainage takes place naturally in all workings above the adit as a result of gravity, and structural support is generally not as expensive or wide-ranging.
The problems seen in the sinking of a shaft can in sometimes be many, particularly if water bearing strata needs to be pierced. The water bearing strata needs to be cemented or frozen before excavation starts, and lining the shaft with concrete also becomes necessary. Even in dry strata, deep shafts are in most cases lined so that they are able with stand the lateral pressures in the rocks through which they are sunk. After the shaft or adit is done, lateral development takes place, and crosscuts are driven to get to the ore deposit at different levels. A wide mine may perhaps have a main hoisting shaft and one or more auxiliary shafts or adits for supplies and ventilation. A lot of state mining laws require mines to be prepared with at least two points of entry and egress to advance the amount of safety for miners.
The method selected for mining will have to do on how much maximum yield can be attained in the existing conditions at a minimum cost, with the least amount of danger to the mining workforce. The surroundings include the shape, size, permanence, and position of the ore body as well as the mineralogical and physical nature of the ore, and the quality of the wall rock or overlying material, the relation of the deposit to the surface, to other ore bodies, and to other shafts that are on the same property, the ability of existing labor, and regional economic situation. These variables are all linked with each other and vary in importance; however maximum profit and maximum extraction are closely related, for the reason that a technique that gives up part of the ore body regularly yields maximum profit. In sight of these considerations, open pit mining has a tendency of being more cost efficient than underground mining, not including the regions where the climatic conditions are so harsh that surface mining is in many cases not possible.