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Rock properties with respect to wear
Published in H.J.R. Deketh, Wear of Rock Cutting Tools, 2020
The results of hardness tests depend not only on the nature of the material but also on the nature of the test itself. Tests, like the Vickers or Brinell hardness tests, which take the indentation diameter of an imprint of a sphere or pyramid, pressed with a prescribed load and period of time into the test body, are, as a measure of hardness, completely different from tests like Rosiwal’s hardness test, which uses the loss of material after grinding the test body with abrasive powder as a measure of hardness or the Mohs hardness test, which uses the ability of one mineral to scratch another as a measure of hardness. Diamond, which cannot be scratched by any other mineral and is thus the hardest, has a hardness value of 10. Talc, which cannot scratch any other mineral, has a value of 1. In Table 2 the hardnesses of some minerals according to three test methods of different nature are listed (Verhoef et al. 1990). It can be seen that the hardness scales are not linearly related.
Review of Basic Chemistry and Geology
Published in Arthur W. Hounslow, Water Quality Data, 2018
Minerals are naturally occurring inorganic compounds having a crystalline structure and a definite chemical composition. Minerals are the basic building blocks of the earth. They are more often than not resistant to chemical decomposition and are not readily amenable to the normal methods of qualitative chemical analysis. Because of this they are often identified on the basis of their physical properties. These same properties are often those for which the mineral is actually mined. In other cases the physical property is used in the recovery of the mineral. These minerals that are heated (smelted) to recover the metal in them are called ore minerals. Other minerals, often those more amenable to chemical solution, are used as raw materials by the chemical industry. These include many minerals formed by evaporation (evaporites).
Minerals and rocks
Published in A.C. McLean, C. D. Gribble, Geology for Civil Engineers, 2017
The composition of a given rock will depend on the source from which the waste material came, on the resistance, chemical and mechanical, of each component during transport, and on the distance travelled. The main constituents of terrigenous sedimentary rocks are fragments from pre-existing rocks and minerals. These may be fresh and unaltered, or may be alteration products of weathering (see Section 2.1.3), such as clay minerals. Quartz is the most common mineral. It is chemically stable and hard enough to resist abrasion as it is transported. Some rarer minerals, such as garnet, tourmaline and rutile, have similar properties. Feldspar is less stable but may survive for long enough, under favourable circumstances, to be present in deposits that have not been transported far from their source, or which are protected in other ways. The other common rock-forming minerals of igneous rocks generally have an even lower survival rate when exposed to air and water (p. 23).
Experimental Investigation of the Effect of Ultrasound on Lixiviant Ion Migration in In-Situ Recovery Processing
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Elahe Karami, Laura Kuhar, Andrej Bona, Aleksandar N. Nikoloski
Gold and copper deposits tend to have grades of less than 1 g/t or 0.62%, respectively. Traditional mining methods, such as open pit mining or underground mining, are used to extract ore from these mineral deposits. Conventional mining methods are becoming more challenging, in part because they require physical excavation, which can be extremely energy-intensive and expensive. Gangue minerals must be removed during mining operations, which results in significant waste production. It is also costly to move and store the extracted rocks afterward. As a result, the sustainability of current mining techniques in ore deposits such as gold and copper is declining, which has necessitated the development of new techniques. One alternative option is in-situ recovery (ISR), which involves using a lixiviant solution to remove metals from valuable minerals without rock excavation.
An unconventional approach in investigating wettability contact angle measurement in shale resources
Published in Petroleum Science and Technology, 2022
Salah Almudhhi, Mohammed Alostath, Waleed Al-Bazzaz, Hamid Sharifigaliuk, Ali Qubian
A mineral is a naturally occurring, crystalline, inorganic solid which is homogeneous chemical composition with limited impurities that has unique internal structure and unique physical properties. Shale is a rock that is naturally occurring solid consists of many common minerals. In Table 2, there are 18 minerals investigated from global data. Some minerals are dominant such as silicates (mainly Clays and Feldspars). Other minerals are less dominant found in shale structures as well, such as oxides (mainly Quartz and to lesser quantities: Hematite and Limonite), others are varied in quantities such as sulfides (Pyrite) and Carbonates (Calcite and Dolomites). The remaining minerals exist as coexistent partner (Halite, Phosphorite, Anhydrite and Gypsum), or elemental such as (Carbon). Also, in each mineral available in the shale rock there are numerous elemental impurities are reported (Table 4).
Assessing occupational erionite and respirable crystalline silica exposure among outdoor workers in Wyoming, South Dakota, and Montana
Published in Journal of Occupational and Environmental Hygiene, 2018
Catherine Beaucham, Bradley King, Karl Feldmann, Martin Harper, Alan Dozier
Another mineral frequently found in continental geological environment is quartz, a form of crystalline silica. Quartz is the most common mineral in the Earth's crust. The same kinds of activities that can aerosolize erionite can also aerosolize crystalline silica. Occupational exposure to airborne respirable crystalline silica (RCS) has been associated with silicosis, lung cancer, and other airway diseases.[21] Several OELs for airborne RCS have been established. The new Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) for respirable crystalline silica of 0.05 milligrams per cubic meter of air (mg/m3), averaged over an 8-hr period, was not in effect at the time of our evaluations.[22] We compared our respirable crystalline silica results to the PEL that was in existence at the time. NIOSH recommends an exposure limit of 0.05 mg/m³, as a time-weighted average (TWA) for up to a 10-hr workday, to reduce the risk of developing silicosis, lung cancer, and other adverse health effects.[23] The American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Values (TLV®) for quartz is 0.025 mg/m³, as an 8-hr TWA.[24] It is not known if there are any synergistic or additive effects of combined exposures to erionite and RCS.