Mineral extenders

With calceous rock types, the oxide mineralization extends beyond the veins forming concretion and small masses. The lead content of these mineralization types range from 1.5% to 2.5%, of which 50% is oxidized. The zinc content ranges from 5% to 12%, of which 70% is oxide zinc. 

Inorganic Extenders. There are many mineral extenders that are commonly used in epoxy adhesive formulations. The more important ones are summarized below. 

FIGURE 9.9 The effect of mineral extenders on the tensile shear strength of epoxy adhesive (the substrate is aluminum).29... 

Niobium (formerly called columbium) and tantalum are Transition Metals having a considerable affinity for oxygen donor groups they are thus called oxophilic see Oxophilic Character). They occur as mixed-metal oxides such as columbites (Fe/Mn)(Nb/Ta)206 and pyrochlore NaCaNb206p. Their discovery in minerals extends back to the beginning of the nineteenth century, when they were believed to be identical and called tantalum. Rose showed that at least two different elements were involved in the minerals, and named the second one niobium. Their separation was resolved around 1866, especially by Marignac. These metals often display similar chemical behavior as a result of nearly identical atomic radii (1.47 A) due to the lanthanide contraction see Periodic Table Trends in the Properties of the Elements)... 

Minex. [Unimin SpecialQ Mrnerab] Sodium potassium aluminosilicate fine ground mineral extender. 

Occupational Health. Some mineral extenders with extremely fine particles (dusts) are governed by special legal provisions. The most important regulations in Ger-... 

Commercial grades of talc used for plastics applications are line-ground products consisting of thin platelets, preferably white in color. Because of their platelike structure, these grades are considered reinforcing fillers, as distinguished from particulate mineral extender fillers. 

Volume of pigments includes the volume of pigments and mineral extenders while "volume of total non-volatiles" includes binders, pigments, additives, extenders, and other non-volatiles. 

With few exceptions, extender pigments can be classified as commodity chemicals. They are manufactured in large quantities with less sophisticated production methods than most pigments. Whereas the majority of pigments is prepared synthetically, extender pigments are mainly manufactured by the beneficiation of natural minerals. Based on chemical composition, extender pigments are carbonate, sulfate, siUca-based, and siUcate-based compounds. 

The Hercules viscometer was originally designed for paper and paperboard coatings, but its use has been extended to paints, adhesives, mineral slurries, emulsions, and starch solutions. The iastmment, noted for being robust and rehable, is particularly well suited for quaUty control and product formulation. It is capable of measuting viscosity over a moderate range 1-10 mPa-s) up to high shear rates (115,000 ). A more recent model is the... 

Uses. Inactive dried yeasts are used as iagredients ia many formulated foods baby foods, soups, gravies, and meat extenders as carriers of spice and smoke flavors and ia baked goods. Yeasts used ia the health food iadustry are geaeraHy fortified with minerals and contain higher concentrations of the B vitamins, especially thiamin, riboflavin, and niacia (see Vitamins). 

The formulation of calcium chelate materials is based upon the formation of a low-solubiUty chelate between calcium hydroxide and a sahcylate. Dycal utilizes the reaction product of a polyhydric compound and sahcyhc acid. Other sahcyhc acid esters can be similarly used. Vehicles used to carry the calcium hydroxide, extenders, and fillers may include mineral oil, A/-ethyl- -toluenesulfonamide [80-39-7] and polymeric fluids. The filler additions may include titanium dioxide [13463-67-7] zinc oxide, sihca [7631-86-9], calcium sulfate, and barium sulfate [7727-43-7]. Zinc oxide and barium sulfate are useflil as x-ray opacifying agents to ensure a density greater than that of normal tooth stmcture. Resins, rosin, limed rosins, and modified rosins may serve as modifiers of the physical characteristics in both the unset and set states. 

Fillers. Diatomite mineral fillers are used primarily (/) where bulk is needed with minimum weight increase, (2) as an extender where economy of more expensive ingredients is a factor, or (3) where the stmcture of the particle is important. In other appHcations, diatomite can add strength, toughness, and resistance to abrasion, or it can act as a mild abrasive and polishing agent (see Abrasives). 

Plasticizers and Processing Aids. Petroleum-based oils are commonly used as plasticizers. Compound viscosity is reduced, and mixing, processing, and low temperature properties are improved. Air permeabihty is increased by adding extender oils. Plasticizers are selected for their compatibihty and low temperature properties. Butyl mbber has a solubihty parameter of ca 15.3 (f /cm ) [7.5 (cal/cm ) ], similar to paraffinic and naphthenic oils. Polybutenes, paraffin waxes, and low mol wt polyethylene can also be used as plasticizers (qv). Alkyl adipates and sebacates reduce the glass-transition temperature and improve low temperature properties. Process aids, eg, mineral mbber and Stmktol 40 ms, improve filler dispersion and cured adhesion to high unsaturated mbber substrates. 

Bag An extended surface filter in the form of a pocket or bag. A typical example of a bag filter is a mineral fiber bag made up of three layers, in which the first layer acts as a prefilter, the second is for fine filtration, and the third prevents fiber migration from the material used. 

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