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Metal–Crucible Interactions
Published in Nagaiyar Krishnamurthy, Metal–Crucible Interactions, 2023
The beginning of the Copper Age or Chalcolithic Age is marked by the emergence of smelting methods to extract copper from its ores. The ores were bright green (malachite: copper carbonate hydroxide), blue (azurite) and metallic looking sulphide ores. It is surmised that malachite, used in Egypt as a green eye pigment, accidentally found its way to a wood or charcoal fire and was reduced to metallic copper. Once it was observed that fire could transform certain earthy and stony materials into metals, rocks or stones that were heavy or strongly coloured would have been thrown into or treated in fire to find out if they would yield metal. Apparently, many did, and pyrometallurgy was born in the most elementary form.
Industrial minerals
Published in Francis P. Gudyanga, Minerals in Africa, 2020
Azurite Cu3(CO3)2·10H2O [791] is produced by the weathering of copper ore deposits. It is characteristically deep and clear blue. It is a minor source of copper. Its presence is a good surface indicator of the occurrence of weathered copper sulphide ores. Azurite and the other basic copper carbonate mineral, malachite, decompose with heat to form CO2 and dark powdery cupric oxide CuO and lose water.
Minerals
Published in Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough, Earth Materials, 2019
Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough
The most significant control on color is a mineral’s chemical composition. We call elements that give a mineral its color chromophores. If the elements controlling the selective reflection of certain wavelengths are major components in a mineral, the mineral is idiochromatic, or “self-coloring.” Sphalerite, (Zn,Fe)S, for example, is an idiochromatic mineral. It changes from white to yellow to brown to black as its composition changes from pure ZnS to a mixture of ZnS and FeS. Many copper minerals are green or blue, while many manganese minerals are pinkish. These colors derive from selective absorption of certain colors by copper and manganese. Complicating things, however, is the fact that idiochromatic elements may have different effects in different minerals. Malachite is green and azurite is blue, but in both minerals the color is due to copper.
Purification of malachite green as a model biocidal agent from aqueous system by using a natural widespread coastal biowaste (Zostera marina)
Published in International Journal of Phytoremediation, 2021
Fatih Deniz, Elif Tezel Ersanli
In the present study, as alternative environmentally friendly and inexpensive biosorbent candidate, the natural widespread coastal waste of aquatic Zostera marina plant was used to purify a model biocidal agent from aqueous system by bioremediation technology. To our literature survey, there is no report concerning the use of Z. marina natural waste for biocide remediation purpose. Herein, malachite green was selected as a common biocide to evaluate the biosorption efficiency of waste biomaterial. Malachite green is one of the triarylmethane class synthetic dye compounds. It has very wide industrial applications. Malachite green is widely used on the one hand as a coloring agent in the industries such as leather, cotton, wool, silk and paper, and on the other hand, it is extensively used as an anti-parasitic compound in the aquaculture industry due to its efficiency in elimination of aquatic diseases, easy availability, and low-cost (Naushad et al.2019; Salamat et al.2019). However, many studies have reported its toxic, teratogenic, carcinogenic, and mutagenic effects on different organisms, especially mammals (Gao et al.2019; Quintela et al.2020). For this reason, removing it from the receiving environment is extremely important to protect nature and living things. The biosorption properties of biosorbent were investigated in a controlled batch experiment system by the optimization practice of operating parameters like biosorbent quantity, medium pH, time, pollutant concentration and temperature, and kinetic, thermodynamic, equilibrium, and characterization operations.
Kinetics of malachite leaching in alkaline glycine solutions
Published in Mineral Processing and Extractive Metallurgy, 2021
B. C. Tanda, E. A. Oraby, J. J. Eksteen
Malachite is a basic carbonate mineral of copper with a chemical formula of CuCO3.Cu(OH)2 occurring as a secondary copper mineral in the oxidised upper zone of copper deposits. Malachite is the most common oxidised mineral of copper with deposits in the Democratic Republic of the Congo, Gabon, Zambia, Namibia, Mexico, Australia (Broken Hill, New South Wales), France (Lyon), Israel (Timna Valley), and the Southwestern United States, most notably in Arizona (Anthony et al. 2001; Mindat.org 2016).