Marble, for use in separation

Manganites, nomenclature of, 2 261 Marble, for use in separation of cerium from rare earth mixtures by bromate method, 2 49 Mercury, solubility of metals in,... 

Western-world bauxite production in 1988 totaled about 90 x 10 t, approximately 90% of which was refined to aluminum hydroxide by the Bayer process. Most of the hydroxide was then calcined to alumina and consumed in making aluminum metal. The balance, which constituted about 2.3 x 10 t in 1988 (Table 2), was consumed in production of abrasives (qv) adhesives (qv) calcium aluminate cement used in binding ceramics (qv) and refractories (qv) catalysts used in petrochemical processes and automobile catalytic converter systems (see Petroleum Exhaust control, automotive) ceramics that insulate electronic components such as semiconductors and spark plugs chemicals such as alum, aluminum halides, and zeoHte countertop materials for kitchens and baths cultured marble fire-retardant filler for acryhc and plastic materials used in automobile seats, carpet backing, and insulation wrap for wire and cable (see Flame retardants) paper (qv) cosmetics (qv) toothpaste manufacture refractory linings for furnaces and kilns and separation systems that remove impurities from Hquids and gases. 

Examples of inert or extender fillers include china clay (kaolin), talc, and calcium carbonate. Calcinm carbonate is an important filler, with a particle size of about 1 pm. It is a natural product from sedimentary rocks and is separated into chalk, limestone, and marble. In some cases, the calcium carbonate may be treated to improve interaction with the thermoplastic. Glass spheres are also used as thermoplastic fillers. They may be either solid or hollow, depending on the particular application. Talc is a filler with a lamellar particle shape. It is a namral, hydrated magnesium silicate with good slip properties. Kaolin and mica are also natural materials with lamellar structures. Other fillers include woUastonite, silica, barium sulfate, and metal powders. Carbon black is used as a filler primarily in the rnbber industry, but it also finds application in thermoplastics for conductivity, for UV protection, and as a pigment. Fillers in fiber form are often used in thermoplastics. Types of fibers inclnde cotton, wood flour, fiberglass, and carbon. Table 1.3 shows the fillers and their forms. An overview of some typical fillers and their effect on properties is shown in Table 1.4. Considerable research interest exists for the incorporation of nanoscale fillers into polymers. This aspect will be discussed in later chapters. 

Uses of oxalic acid ia each region are summarized in Table 5 (58). The demand for agrochemical/pharmaceutical production and for separation/recovery of rare-earth elements in each region has been increasing. The use for marble polishing in western Europe is unique to the region. 

As primary material for the preparation of food extracts, we can also use malt, hay or clover. Malts must be completely cleaned, and should contain at the most not more than 6 per cent of water in order to preserve well. The product obtained with malts or hay is a thick, brown syrup, of a pronounced odor recalling meat extract. Before the malts are allowed to react with the add, they must be separated as far as possible from the sugar and the starch which th contain. This result is attained by lactic fermentation. For this purpose, i part of malt and 2 parts of water are heated under a pressure of 2 atmospheres. The mass is cooled to 50 , pieces of marble are added to neutralize tixe add, and the mixtiure is inoculated with a lactic... 

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