Magnesium metallurgy

Magnesium Metallurgy Magnesium has become increasingly important as a structural metal. Its great advantages are its low density (1.74 g/cm, which compares with 7.87 g/cm for iron and 2.70 g/cm for aluminum, the other important structural metals) and the relative strength of its alloys. 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

An alternative commercial form of a metallic mixed lanthanide-containing material is rare-earth siUcide [68476-89-1/, produced in a submerged electric-arc furnace by the direct reduction of ore concentrate, bastnasite, iron ore, and quart2. The resulting alloy is approximately 1/3 mischmetal, 1/3 sihcon, and 1/3 iron. In addition there are some ferro-alloys, such as magnesium—ferrosilicons, derived from cerium concentrate, that contain a few percent of cerium. The consumption of metallic cerium is overwhelmingly in the mixed lanthanide form in ferrous metallurgy. 

Refractory brick -magnesium compounds m [MAGNESIUMCOMPOUNDS] (Vol 15) -use m ladle metallurgy [STEEL] (Vol 22)... 

There are minor uses for magnesium peroxide in household products, veterinary medicine, and metallurgy. Magnesium peroxide is a strong oxidizer and can cause fire when in contact with combustible materials. It is a powerful irritant to skin, eyes, and mucous membranes. 

Roasting furnaces are used to react sulfides to produce metal oxides, which can be converted to metals in the next process step. The sulfides are used as a reducing agent in nonferrous metallurgy for the recovery of metals. The process has been used for metals such as copper, lead, zinc, nickel, magnesium, tin, antimony, and titanium. 

The Metallurgy of Iron. The ores of iron are usually first roasted, in order to remove water, to decompose carbonates, and to oxidize sulfides. They are then reduced with coke, in a structure called a blast furnace (Fig. 26-2). Ores containing limestone or magnesium carbonate are mixed with an acidic flux (containing an, excess of silica), such as sand or clay, in order to make a liquid slag. Limestone is used as flux for ores containing an excess o silica. The mixture of ore, flux, and coke is introduced at the top of the blast furnace, and pre heated air is blown in at the bottom through tuyeres. As the solid... 

Calcium is utilized in the manufacture of special metals such as zirconium, thorium, uranium and the rare earths, as a refining agent in metallurgy (steel, copper, magnesium, tantalum, lead) and in the manufacture of calcium hydride (hydrogen source). 

Use Vitreous enamel frits, synthetic mica, metallurgy of aluminum and magnesium, ceramics, insecticide, opalescent glass. 

Describe the specific metallurgies of five metals magnesium, aluminum, iron, copper, and gold... 

Magnesium has been determined with the use of Eriochrome Black T in waters [61], soil extracts and rocks [18], non-ferrous metallurgy products [62], nickel, zinc, and manganese salts [2], and sodium chloride [1]. 

Metallurgy. — Metallic, rubidium may be prepared in a variety of ways (1) electrolysis of the fused chloride, (2) heating RbOH with aluminium or mugnesinin, fH) heating Rb,t 0 with carhon or magnesium, (4) heating It Iff 1 wilh calcium, (5) heating the tartrate to white heat. 

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