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Materials Used for General Radiation Detection
Published in Alan Owens, Semiconductor Radiation Detectors, 2019
Mercury oxide has also been proposed as a room-temperature detection medium in view of its high density (11.14 g cm3) and favourable bandgap (2.2 eV). At normal pressures, HgO has two crystalline forms: an orange orthorhombic form known as montroydite, which is rarely encountered in nature, and a second, red hexagonal, form, which is analogous to the sulfide mineral cinnabar. Both are characterized by Hg-O chains in a zigzag pattern, which in turn are packed to form planar layers. At pressures above 10 GPa both structures convert to a tetragonal form. However, for radiation detection, HgO has several disadvantages – it is soft, sectile, very toxic and decomposes into mercury and oxygen on exposure to light or on heating above 500°C. Because of its toxicity, HgO is used in a limited number of applications – mainly as base in marine and porcelain paints, with graphite as a depolarizer in dry batteries and ironically in some skin ointments.
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Hydrogrossularite Hydromagnesite Illite Ilmenite Iodyrite Jacobsite Jadeite Jamesonite Jarosite Kainite Kaliophilite Kaolinite Kyanite Lanarkite Lanthanite Laumontite Laurionite Lawsonite Lazulite Lazurite Leadhillite Lepidocrocite Lepidolite Leucite Levyne Litharge Loellingite Maghemite Magnesite Magnetite Malachite Manganite Manganosite Marcasite Marialite Marshite Matlockite Meionite Melilite Mellite Mendipite Mesolite Metacinnabar Microcline Miersite Millerite Mimetite Molybdenite Monazite Monticellite Montmorillonite Montroydite Mordenite Muscovite Nantokite Natrolite Nepheline Norbergite Nosean
Leaching of Mercury from Contaminated Solid Waste: A Mini-Review
Published in Mineral Processing and Extractive Metallurgy Review, 2020
Feng Xie, Kaiwei Dong, Wei Wang, Edouard Asselin
Rodríguez et al. (2012) reported that ionic forms of mercury are strongly adsorbed in soils and sediments and desorb slowly. Clay minerals optimally adsorb mercury ions at pH 6 while iron oxides adsorb mercury ions in neutral soils. Mercury ions are adsorbed by organic matter, mainly fulvic and humic acids, in acidic soils. The following mercury species are commonly found in mercury-contaminated waste: Hg, HgCl, HgCl2, HgO/Hg(OH)2, HgS and the methyl-mercury compounds such as CH3HgCl and CH3HgOH (Benes and Havlik 1979; Dyrssen and Wedborg 1991; Bloom and Lasorsa 1999; Horvat et al. 2003; Kim et al. 2004). Elemental mercury (Hg) is virtually insoluble in water (0.05 mg/L at 25°C) while mercuric oxide (in the form of montroydite in nature, HgO), which is a type of alkaline oxide, has solubility of 15.8 mg/L in water at 25°C. Mercuric oxide has high solubility in diluted hydrochloric acid, dilute nitric acid and alkaline cyanide. Comparatively, calomel, Hg2Cl2, is sparingly soluble in water at about 2 mg/L at 25°C. Mercury sulfide (HgS) is virtually insoluble in water (at about 0.017 mg/L at 25°C). Mercury sulfide exists in two forms: HgS red (hexagonal form) found in nature as cinnabar (α-HgS), and HgS black (cubic tetrahedral form or amorphous) or meta-cinnabar (β-HgS).