Calcium sulfate extended

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. 

The polysulfide base material contains 50—80% of the polyfunctional mercaptan, which is a clear, amber, sympy Hquid polymer with a viscosity at 25°C of 35, 000 Pa-s(= cP), an average mol wt of 4000, a pH range of 6—8, and a ntild, characteristic mercaptan odor. Fillers are added to extend, reinforce, harden, and color the base. They may iaclude siUca, calcium sulfate, ziac oxide, ziac sulfide [1314-98-3] alumina, titanium dioxide [13463-67-7] and calcium carbonate. The high shear strength of the Hquid polymer makes the compositions difficult to mix. The addition of limited amounts of diluents improves the mix without reduciag the set-mbber characteristics unduly, eg, dibutyl phthalate [84-74-2], tricresyl phosphate [1330-78-5], and tributyl citrate [77-94-1]. 

Venetian red is a mixture of ferric oxide with up to an equal amount of the pigment extender, calcium sulfate. This pigment is manufactured by heating ferrous sulfate with quicklime in a furnace. Venetian red is a permanent and inert pigment, particularly on wood. The calcium sulfate content, which furnishes corrosion-stimulating sulfate ions, disqualifies this pigment for use on iron. 

Veining in CM chondrites. Rare examples of veins in CM chondrites have been documented in the literature. Lee (1993) described calcium sulfate veins crosscutting the matrix of Cold Bokkeveld, and Hanowski and Brearley (2000) found thin veins of iron oxyhydroxide associated with altered metal grains in chondrules in Murchison. These veins cut across fine-grained rims and extend into the matrix of the chondrite (Figure 4), demonstrating that metal-alteration occurred after accretion of the chondrule and its fine-grained rim into the parent body. 

Titanox [Velsicol], TM of a series of white pigments comprising titanium dioxide in both ana-tase and rutile crystalline forms and also extended with calcium sulfate (titanium dioxide-calcium pigment). Noncombustible. 

The latter procedure has so far been applied successfully (/) to a large number of silicas suitable for column chromatography (60-200 mesh). Attempts to extend these techniques to thin-layer silicas have not been successful. In the case of silicas with calcium sulfate binder, experimental values of 5,. and St appear quite variable and do not agree with values that can be inferred from surface area, pore diameter, and chromatographic activity data. This suggests that calcium sulfate in some way interferes with the silica-silane reaction. For thin-layer silicas without binder, erroneously low values of S jSf are obtained. This is believed to be due to... 

Diatomaceous earth Magnesium oxide Pyrophyllite Quartz Silica, hydrated Sodium silicate Sodium silicoaluminate Terpene resin Wollastonite Xanthan gum extender, paints/coatings Calcium carbonate Kaolin extender, paper Calcium sulfate dihydrate extender, paper coatings Wollastonite extender, paper sizing Kaolin Xanthan gum extender, paperboard Wood flour... 

Silicone emulsion Wollastonite extender, polishes Calcium monocarbonate extender, polishing powders Calcium sulfate dihydrate extender, polyamide resins Tosylamide/formaldehyde resin extender, polymeric systems Amines, C18-unsaturated alkyl, dimers extender, printing inks Coumarone/indene resin Kaolin extender, PU... 

Blast-furnace slag can also be used with 10% calcium sulfate and 5% Portland cement to produce supersulfated cement. However, it is much more commonly used to extend and improve Portland cement. 

Inert i- nort [L inert-, iners unskilled, idle, fr. in- 4- art-, ars skill] (1647) adj. The term apphed to various extended pigments such as asbestine, barites, silica, calcium sulfate, mica, talc, etc. In general, they have poor hiding power but they are inert from a chemical and physical standpoint. While they contribute some desirable properties to paint, they are primarily used to lower the cost. 

Hardeners are used to cure a paint system and include amines, peroxides and polyamides (Mathias 1984). Extenders are noncovering pigments which improve thickness, adhesion, durability and gloss. Examples are barium and calcium sulfates, calcium... 

In wet limestone FGD systems, the complete oxidation to calcium sulfate normally requires the introduction of a step that is optimized for oxygen absorption. In this step, air is bubbled into the absorber sump/reaction tank to provide forced oxidation. Due to the low solubility of oxygen in water, forced oxidation is aided by extended liquid residence time. Increased residence time generally also increases limestone utilization (Head, 1977). Many newer limestone/lime FGD systems operate with 6 to 10 minutes residoice time in the reaction tank. This is lower than used in some early systems whore residence times were 10 to 40 minutes. The nuiin difference is that current designs are based on a better undorstanding of the FGD chemistry. 

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. 

Transparent white pigments (extenders) commonly used in inks, in order of decreasing transparency, ate alumina hydrate, magnesium carbonate, calcium carbonate, blanc fixe (precipitated barium sulfate), talc, and clay. Extenders ate sometimes used to reduce the color strength and change the theology of inks. 

Available Forms. Phthalocyanines are available as powders, in paste, or Hquid forms. They can be dispersed in various media suitable for aqueous, nonaqueous, or multipurpose systems, eg, polyethylene, polyamide, or nitrocellulose. Inert materials like clay, barium sulfate, calcium carbonates, or aluminum hydrate are the most common soHd extenders. Predispersed concentrates of the pigments, like flushes, are interesting for manufacturers of paints and inks (156), who do not own grinding or dispersing equipment. Pigment—water pastes, ie, presscakes, containing 50—75% weight of water, are also available. 

Since many ion exchange columns exhibit mixed-mode interactions with analytes, factor analysis has been found to be useful in optimization.84 A 3-year, comprehensive review of inter-laboratory errors in determinations of the anions chloride, nitrate, and sulfate and the cations sodium, potassium, magnesium, and calcium suggested that multipoint calibration is essential and nonlinear calibration desirable.102 The need for nonlinear calibration was confirmed by an extended quality assurance study of chloride, sulfate, and nitrate in rainwater.103... 

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