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Copper and its alloys
Published in William Bolton, R.A. Higgins, Materials for Engineers and Technicians, 2020
In my early history lessons we were told that about 3500 years ago, the Stone Age was followed by the Bronze Age; but it seems very likely that metallic copper was used in Egypt even earlier, some 1500 years before bronze (an alloy of copper and tin) was discovered. Since copper is more easily corroded than bronze, only limited evidence of this early use of copper remains. Nevertheless, we can regard copper as the most ancient metal of any engineering significance. Brass – a copper-zinc alloy – was, in classical times, made by smelting together ores of copper and zinc. The extraction of metallic zinc was not possible at that time; in fact, not until the sixteenth century. The Romans made their brass by smelting copper along with the zinc ore calamine (zinc carbonate). The Romans used brass for coinage and ornaments, and bronze for fittings on important buildings, e.g. bronze pillars, tiles and doors. In ancient times, the world's output of copper – mainly for bronze manufacture – was ultimately outstripped by that of iron and, during the twentieth century, by aluminium.
Metallurgy
Published in Andrew N. Sherwood, Milorad Nikolic, John W. Humphrey, John P. Oleson, Greek and Roman Technology, 2019
Andrew N. Sherwood, Milorad Nikolic, John W. Humphrey, John P. Oleson
Brass, an alloy of copper and zinc, was used for coinage by the Romans from the Augustan period onwards. Its earlier history, however, is not well known. Since zinc occurs only in compounds and was not produced in pure form until the development of distillation in the sixteenth century ac, zinc oxide was often obtained as a by-product when treating ores of lead, silver, iron, and copper; Roman brass was produced from calamine, a compound of zinc oxide. Other zinc ores, contaminated by clay, iron, and calcite oxides, have an earthy appearance that was recognised in antiquity. This “special earth” had the property of giving the colour of gold to copper when smelted together with it. It may be the substance referred to in the following passage, although this has also been identified as a copper-arsenic alloy (Craddock 1978, 1977).
Metals, Their Biological Functions and Harmful Impacts
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Cadmium was discovered in 1817 by the German chemist Friedrich Strohmeyer, as a byproduct of the zinc refining process. The chemist noticed that some samples of zinc carbonate (calamine) changed colour when heated. Pure calamine, however, did not. Strohmeyer surmised there must be an impurity present and eventually isolated it by heating and reducing the zinc carbonate. What he isolated was cadmium metal. Strohmeyer coined the name cadmium, derived from the Latin word cadmia which means calamine.
An overview of the plant-mediated synthesis of zinc oxide nanoparticles and their antimicrobial potential
Published in Inorganic and Nano-Metal Chemistry, 2020
Sadia Akbar, Isfahan Tauseef, Fazli Subhan, Nighat Sultana, Ibrar Khan, Umair Ahmed, Kashif Syed Haleem
Medical properties of zinc oxide have been known for years. Calamine lotion, containing a mixture of iron oxide (Fe2O3) with zinc oxide, is employed as a topical treatment for pain and itching from poison oak, poison ivy, poison sumac, rashes, sunburns and insect bites. Zinc oxide combined with eugenol ligand, called zinc oxide eugenol, is used as a prosthodontic and restorative in dentistry.[126,127] Zinc oxide is a component of a variety of skin products, such as antiseptic ointments, anti-dandruff shampoos, barrier creams to treat diaper rashes, baby powder and calamine cream.[128] It is also used in zinc oxide tape as a bandage by athletes, to avoid soft tissue damage during workouts.[129] Zinc oxide powder is generally utilized to induce antimicrobial effect but when zinc oxide nanoparticles are used, it results in an enhancement of its antimicrobial potential due to the photocatalytic ability of nanoparticles under UV and a huge increase in the surface area available for the microbes to be exposed.[130] Reflecting the basic properties of zinc oxide, zinc oxide nanoparticles are added into materials including rubber, oral care products and cotton fabrics[131,132] for deodorizing and antibacterial activities.[123] Zinc oxide nanoparticles have been extensively investigated for antibacterial,[99] antifungal,[133] and for drug delivery applications.[134] The demonstrated antibacterial activity of zinc oxide nanoparticles recommends its potential application in the food packaging and preservation field.[135,136] Nanoscale zinc oxide is a constituent of lotions, creams and ointments to treat sunburn and other skin damages caused by ultraviolet light. It is approved by the U.S. Food and Drug Administration (FDA) as a sunscreen because it is completely photo-stable and the broadest spectrum UVA and UVB reflector.[94]