Company Name | : | MEYRA MÜHENDİSLİK PROJE VE MADENCİLİK SAN. TİC. A.Ş. |
Location | : | İSTANBUL / KAĞITHANE |
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Tel | : | +90(212) 311 44 00 |
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MINERALS ZINC ORES AND CONCENTRATES Zinc is the 23rd most abundant element in the earth's crust. Sphalerite, zinc sulfide, is and has been the principal ore mineral in the world. Zinc is necessary to modern living, and, in tonnage produced, stands fourth among all metals in world production - being exceeded only by iron, aluminum, and copper. Zinc uses range from metal products to rubber and medicines. About three-fourths of zinc used is consumed as metal, mainly as a coating to protect iron and steel from corrosion (galvanized metal), as alloying metal to make bronze and brass, as zinc-based die casting alloy, and as rolled zinc. The remaining one-fourth is consumed as zinc compounds mainly by the rubber, chemical, paint, and agricultural industries. Zinc is also a necessary element for proper growth and development of humans, animals, and plants; it is the second most common trace metal, after iron, naturally found in the human body. SPHALERITE Sphalerite ((Zn,Fe)S) is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides along with calcite, dolomite, and fluorite. Miners have also been known to refer to sphalerite as zinc blende and black-jack.
MINERALS LEAD ORES AND CONCENTRATES Lead is a chemical element in the carbon group with symbol ,atomic number 82. Lead is a soft and malleable metal, which is regarded as a heavy metal and poor metal. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed to air. Lead has a shiny chrome-silver luster when it is melted into a liquid. Lead is used in building construction, lead-acid batteries, bullets and shot, weights, as part of solders, pewters, fusible alloys, and as a radiation shield. Lead has the highest atomic number of all of the stable elements, although the next higher element, bismuth, has a half-life that is so long (much longer than the age of the universe) that it can be considered stable. Its four stable isotopes have 82 protons, a magic number in the nuclear shell model of atomic nuclei. GALENA Galena is a lead sulfide mineral commonly found in hydrothermal veins; or as fracture filings, cavity fillings and replacements in limestone. Lesser amounts are found in many igneous, metamorphic and sedimentary rocks. Galena is the primary ore of lead and is often mined for its silver content (silver substitutes for lead within the galena structure). Its perfect cleavage, silver color and very high specific gravity make it very easy to identify. Galena is the most important ore of lead. Most lead is consumed in making batteries, however, significant amounts are also used to make lead sheets, pipe and shot. It is also used to make low-melting-point alloys. Its use as a pigment has declined as has its use in making solder.