Search results
Results from the WOW.Com Content Network
Mineral resource estimation is used to determine and define the ore tonnage and grade of a geological deposit, from the developed block model.There are different estimation methods used for different scenarios dependent upon the ore boundaries, geological deposit geometry, grade variability and the amount of time and money available.
Monolith with bull, fox, and crane in low relief at Göbekli Tepe. The density of most stone is between 2 and 3 tons per cubic meter. Basalt weighs about 2.8 to 3.0 tons per cubic meter; granite averages about 2.75 metric tons per cubic meter; limestone, 2.7 metric tons per cubic meter; sandstone or marble, 2.5 tons per cubic meter.
A rock mass with a high RMR before the adjustment factors are applied has a high reinforcement potential, and can be reinforced by, for example, rock bolts, whatever the MRMR value might be after excavation. Contrariwise, rock bolts are not a suitable reinforcement for a rock mass with a low RMR (i.e. has a low reinforcement potential).
The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973. [1] Since then it has undergone multiple modifications out of which, RMR89 [1] is commonly used.
In surface mining, stripping ratio or strip ratio refers to the amount of waste (or overburden) that must be removed to release a given ore quantity. [1] [2] It is a number or ratio that express how much waste is mined per unit of ore.
The numerical values of the class boundaries for the different rock mass qualities are subdivisions of the Q range on a logarithmic scale. The Q-value determines the quality of the rock mass, but the support of an underground excavation is based not only on the Q-value but is also determined by the different terms in the above equation. This ...
Normative mineralogy is an estimate of the mineralogy of the rock. It usually differs from the visually observable mineralogy, at least as much as the types of mineral species, especially amongst the ferromagnesian minerals and feldspars, where it is possible to have many solid solution series of minerals, or minerals with similar Fe and Mg ratios substituting, especially with water (e.g ...
The Geological Strength Index (GSI) system, proposed in 1994 by Evert Hoek, is used for the estimation of the rock mass strength and the rock mass deformation modulus.. The GSI system concentrates on the description of two factors, rock structure and block surface conditions.