The object of blasting is to fragment the rock and then displace it into a pile that will facilitate its loading and transport. In large open pits the main implements for loading are electric, diesel-electric, or hydraulic shovels, while electric or mechanical-drive trucks are used for transport. The size of the shovels is generally specified by dipper, or bucket, size; those in common use have dipper capacities ranging from 15 to 50 cubic metres (20 to 65 cubic yards). This means that 30 to 100 tons can be dug in a single “bite” of the shovel. The size of the trucks is matched to that of the shovel, a common rule of thumb being that the xcritical official site truck should be filled in four to six swings of the shovel. Thus, for a shovel of 15-cubic-metre capacity, a truck having a capacity of 120 to 180 tons (four to six swings) should be assigned.
Land Disturbance and Reclamation after Mining
Nearby water sources can become contaminated due to the dumping of excavated material, as well as from the use of extraction solvents. Strip mining also releases toxins and dust in the air resulting in poorly controlled contamination. Strip mining is also considered a much quicker procedure as tunnels don’t need to be dug and supported. As a result, minerals don’t need to be lifted on long routes to get to the surface. In other words, retrieval and transport are so much more efficient using the strip mining technique.
Unit operations
Of the several techniques for determining which of the blocks should be included in the final pit, the most common is the floating cone technique. In two dimensions the removal of a given ore block would require the removal of a set of overlying blocks as well. All of these would be included in an inverted triangle with its sides corresponding to the slope angle, its base lying on the surface, and its apex located in the ore block under consideration. The economic value of the ore block at the apex of the cone would be compared with the total cost of removing all of the blocks included in the cone.
Strip mining
Federal governments have imposed multiple laws and regulations which mining companies have to strictly follow. In the United States, the Surface Mining Control and Reclamation Act of 1977 mandates reclamation of surface coal mines.17 Reclamation for non-coal mines is regulated by state and local laws, which may vary widely. Strip mining is the practice of mining a seam of mineral, by first removing a long strip of overlying soil and rock (the overburden); this activity is also referred to as overburden removal. Strip mining involves a series of steps that begin with the removal of overburden, which refers to the layers of soil, rock, and vegetation covering the target resource.
- Some large surface coal mines, such as Wyodak near Gillette in eastern Wyoming have a power plant on-site to utilize the coal at the mine and sell electricity directly into the national grid.
- Other types of mining methods include mountaintop removal, dredging and highwall mining (an adapted form of auger mining done from the surface).
- The consequence of the excavation of open-pits and other mining-related disturbances is that sulfide minerals previously isolated from the atmosphere are exposed to oxygen.
- Economic factors such as costs and expected revenues, which vary with grade and block location, are then applied; the result is an economic block model.
Though far more recent, ecologists hope these “orphan islands” will allow interesting case studies of genetic isolation. Trough-type subsidence resulting from mining low and medium thickness, horizontal or slightly inclined seams; appear like natural depressions. A schematic view of complete operating cycle of mining for shallow-bedded deposits like coal and lignite seam. Another simple thing you can do is use recycled resources (or renewable resources if we’re talking energy) instead of mined materials.
Strip mining has a long history that dates back to the early 20th century. It emerged as a popular method for extracting coal and other minerals due to its efficiency and cost-effectiveness. Over the decades, the practice has evolved significantly, influenced by technological advancements and changing environmental regulations. Strip mining relies on a variety of tools and technologies to efficiently extract minerals from the earth. These tools and technologies are designed to maximize productivity while minimizing environmental impact.
Strip mining is used for mining phosphate fertilizer in Florida, North Carolina, and Idaho, and for obtaining gypsum (mainly for wallboard) in xcritical rezension western states. It has been estimated that more than two-thirds of the world’s yearly mineral production is extracted by surface mining. There are several types of surface mining, but the three most common are open-pit mining, strip mining, and quarrying.