Baryte

Fillers (qv) are occasionally used in flexible slab foams the two most commonly used are calcium carbonate (whiting) and barium sulfate (barytes). Their use level may range up to 150 parts per 100 parts of polyol. Various other ingredients may also be used to modify a flexible foam formulation. Cross-linkers, chain extenders, ignition modifiers, auxiHary blowing agents, etc, are all used to some extent depending on the final product characteristics desired. 

The names adopted for salts consisted of a generic part derived from the acid and a specific part from the metallic base r oxide de plomb + I acide sulfurique le sulfate de plomb. The names for salts of acids containing an element in different degrees of oxidation were given different terminations sufte de soude and sulfate de soude for sodium sulfite and sulfate, and nitrite de baryte and nitrate de baryte for barium nitrite and nitrate. 

Barium [7440-39-3] Ba, is a member of Group 2 (IIA) of the periodic table where it Hes between strontium and radium. Along with calcium and strontium, barium is classed as an alkaline earth metal, and is the densest of the three. Barium metal does not occur free in nature however, its compounds occur in small but widely distributed amounts in the earth s cmst, especially in igneous rocks, sandstone, and shale. The principal barium minerals are barytes [13462-86-7] (barium sulfate) and witherite [14941-39-0] (barium carbonate) which is also known as heavy spar. The latter mineral can be readily decomposed via calcination to form barium oxide [1304-28-5] BaO, which is the ore used commercially for the preparation of barium metal. 

Barite [13462-86-7], natural barium sulfate, BaSO, commonly known as barytes, and sometimes as heavy spar, tiU, or cawk, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. Commercial deposits are of three types vein and cavity filling deposits residual deposits and bedded deposits. Most commercial sources are replacement deposits in limestone, dolomitic sandstone, and shales, or residual deposits caused by differential weathering that result in lumps of barite enclosed in clay. Barite is widely distributed and has minable deposits in many countries. 

In the glass (qv) and ceramic industry (see Ceramics), barite can be used both as a flux, to promote melting at a lower temperature or to increase the production rate, and as an additive to increase the refractive index of glass. The viscosity of barite-containing glass often needs to be raised. Alumina in the form of feldspar is sometimes used. To offset any color produced by iron from the barite addition, more decolorizer may be needed. When properly used, barytes help reduce seed, increase toughness and brilliancy, and reduce annealing time. Barite is also a raw material for the manufacture of other barium chemicals. 

Minerals are generally added to improve wear resistance at minimum cost. The most commonly used are ground limestone (whiting) and barytes, though various types of clay, finely divided siHcas, and other inexpensive or abundant inorganic materials may also perform this function. 

For electrical insulation china clay is commonly employed whilst various calcium carbonates (whiting, ground limestone, precipitated calcium carbonate, and coated calcium carbonate) are used for general purpose work. Also occasionally employed are talc, light magnesium carbonate, barytes (barium sulphate) and the silicas and silicates. For flooring applications asbestos has been an important filler. The effect of fillers on some properties of plasticised PVC are shown in Figure 12.21 (a-d). 

Atz-barkeit,/. corrodibility (Calico) dischargeability. baryt, m. caustic baryta (barium hydroxide), -beizdruck, n. discharge printing. beize, /. chemical discharge, discharge mordant. 

Spat lackp m. barytes lake, -sandp m. silica sand. Saure, /. hydrofluoric acid, -stein, m. selenite (the mineral). 

Strahl-antrieb, m. jet propulsion, -apparat, m. jet apparatus (as steam-jet injector, pump, or blower), -asbest, m. plumose asbestos, -baryt, m. radiated barite, Bologna stone, -blende, /. a variety of sphalerite. -dUse, /. jet nozzle. 

Since 1960, the inner core has been made from c/5-poly-butadiene by the compression moulding technique. This replaced the earlier material made from a suspension of barytes or bentonite clay in water and glycerine or the winding of rubber threads made from t /5-polyisoprene, either from latex or a dry rubber compound. A typical thread recipe is given Table 4. 

Noweoy R, Marr IL, Ansari TM, Muller H 1999) Direct analysis of solid samples by GFAAS -determination of trace hea-vy metals in barytes. Fresenius ( Anal Chem 364 533-540. 

Certain minerals may be mined and processed for more than one purpose. For instance, bauxite, on the one hand, can be utilized for making bricks or abrasives and, on the other, is used for the production of aluminum. It is often found that many nonmetallic minerals are associated with metalliferous minerals. As an example mention may be made of galena, the main mineral source of lead, which is found very frequently to be associated with fluorite (CaF2) and barytes (BaS04), both of which are important industrial minerals. 

Intermediate Barytes, fluor- Jaw cmshers Ball, pebble, Ball, pebble and Moh s hardness... 

Baddeleyite, see Zirconium(IV) oxide Baking soda, see Sodium hydrogen carbonate Barite (barytes), see Barium sulfate... 

Barthlott, Wilhelm, 22 108 Bartles-Mozley concentrator, 16 631 Baryte, as filler, 11 311 Basan, molecular formula and structure, 5 94t... 

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