- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
A drilling bit tipped with tungsten carbide. A 9% cobalt carbide generally gives the best results, and comparisons are usually referred to bits of this standard. Tests with tungsten carbide bits indicate that efficient drilling is possible only up to a hardness of about 55 Shore; beyond this, wear increases rapidly until, at 62 Shore, the cost becomes prohibitive. Several factors affect the cutting life of the bits, including the grade of carbide used, the rake angle of the cutters, the length of cutting edges, and support of cutters.
Industry:Mining
A drilling machine that operates as a purely rotary machine to which is added a percussive action. The specially designed rotary-percussive drilling bit not only gives a 2709 greater penetration rate, but is also able to operate longer without deterioration of the cutting edges. A disadvantage is the great size of the air-operated machine, which is usually mounted on a carriage.
Industry:Mining
A drilling method utilizeing a great number of short blows in quick succession rather than a few heavy blows from a relatively considerable altitude. In this method, the bit is fixed either to a rod or to a rope, so that it pounds the bottom in quick succession with short blows and at the same time rotates.
Industry:Mining
A drilling mud in which the gelatinous constituents, such as bentonite, will remain in suspension in water for a long time.
Industry:Mining
A drilling term describing the total amount of any load or pressure, expressed in kilograms, pounds, or tons, that is applied to a bit when it is in use.
Industry:Mining
A drill-rod coupling that has been permanently attached to the body of the rod by a metal dowel (or pin) driven into a small hole drilled at the point in the rod where the coupling is screwed into the body of the rod.
Industry:Mining
A drill-rod safety clamp somewhat similar to a Wommer's safety clamp.
Industry:Mining
A drive employing an auxiliary belt that bears against the surface of the conveying belt as it passes around the drive pulley to increase the pressure between the conveyor belt and the drive pulley.
Industry:Mining
