White bentonite

Korthix Thixotropic Agent Refined white bentonite Kaopol-... 

Chem. Descrip. Very white bentonite CAS 1302-78-9 EINECS/ELINCS 215-108-5 Uses Thixotrope for water-based applies. 

White bentonite - This is bentonite diat is naturally hght enough in eolor for use in color-sensitive appUeations such as pharmaceuticals, cosmetics, ceramics, laundry products, and the paper industry. 

Minerals, particularly Bentonite, ate used to remove proteins that tend to cause haze in white wines. The natural tannin of ted wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyttohdone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen ate often used to fine ted wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

Various other soft materials without the layer—lattice stmcture are used as soHd lubricants (58), eg, basic white lead or lead carbonate [598-63-0] used in thread compounds, lime [1305-78-8] as a carrier in wire drawing, talc [14807-96-6] and bentonite [1302-78-9] as fillers for grease for cable pulling, and zinc oxide [1314-13-2] in high load capacity greases. Graphite fluoride is effective as a thin-film lubricant up to 400°C and is especially useful with a suitable binder such as polyimide varnish (59). Boric acid has been shown to have promise as a self-replenishing soHd composite (60). 

Sodium Dispersions. Sodium is easily dispersed in inert hydrocarbons (qv), eg, white oil or kerosene, by agitation, or using a homogenizing device. Addition of oleic acid and other long-chain fatty acids, higher alcohols and esters, and some finely divided soHds, eg, carbon or bentonite, accelerate dispersion and produce finer (1—20 -lm) particles. Above 98°C the sodium is present as Hquid spheres. On cooling to lower temperatures, soHd spheres of sodium remain dispersed in the hydrocarbon and present an extended surface for reaction. Dispersions may contain as much as 50 wt % sodium. Sodium in this form is easily handled and reacts rapidly. For some purposes the presence of the inert hydrocarbon is a disadvantage. 

Fillers (calcium carbonate, calcium sulfate, aluminum oxide, bentonites, wood flour) increase the solid content of the dispersion. They are added up to 50%, based on PVAc. The purpose of the addition is the reduction of the penetration depth, provision of thixotropic behavior of the adhesive, gap filling properties and the reduction of the costs. Disadvantage can be the increase of the white point and a possible higher tool wear. 

Silicates with layer. structures include some of the most familiar and important minerals known to man, partieularly the clay minerals [such as kaolinite (china clay), montmorillonite (bentonite, fuller s earth), and vermiculite], the micas (e.g. muscovite, phlogopite, and biotite), and others such as chrysotile (white asbestos). 

Duncan, B. (1992). Varietal differences in white grape protein Implications for bentonite fining. Aus. New Zealand Wine Ind.. 7,189-193. 

BENTONITE. The term applied to alteied fine-grained volcanic ashes which have been blown considerable distance from their origin and deposited m marine waters. The resulting material is usually a white, but sometimes a colored, clay-like sediment which may contain bits of volcanic glass but is composed mainly of colloidal silica which will absorb large quantities of water. Since bentonites are wind-blown deposits they are useful as definite datum planes in stratigraphy, especially in helping to determine the contemporaneity of the different facies of marine sediments. 

In a screw-capped vial were placed malonic acid (0.52 g, 5.0 mmol, 3 equiv.), p-tolualdehyde lc (0.20 g, 1.67 mmol) and bentonite (0.72 g). The tube was capped and the contents of the tube were thoroughly mixed with a vortex mixer and then irradiated in the microwave oven for 5 min at a power of 1050 W. After the reaction the mixture was cooled to room temperature and washed successively with hexane (3xl0mL) and cold water (3xl0mL). The resulting mixture was immersed in ethyl acetate (2x10 mL) for 5 min. After removal of bentonite by filtration under vacuum, the mixture was evaporated under reduced pressure to give 2-(4-methylbenzylidene)malonic acid 2c as a white solid (0.29 g, 86%). This solid was recrystallized from hot, distilled water, mp 205-208 °C. 

Yellow or White Form. Cover with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. Moisten with water. Scoop into a container and cover with water. Transfer the container to the fume hood. Add 1 M cupric sulfate solution (127.7 g or 199.7 g of CuS04 or CuS04-5H20, respectively, dissolved in 800 mL of water about 160 mL for each 1 g of phosphorus). Allow it to stand for a week. Decant the liquid to the drain with at least 50 volumes of water. Add laundry bleach to the solid (about 100 mL for each 1 g of phosphorus). Stir for 1 hour. The liquid can be washed into the drain and the solid treated as normal refuse.31 33... 

Fining is a winemaking technique used to enhance sensory or clarity properties of the wines. Common fining agents used with North Coast white wines are bentonite (a clay), casein (milk protein), gelatin (animal protein),... 

Bentonite is a colloidal clay that is both hydrophilic and organophilic. It is waterswelling with some types of clay absorbing as much as 5 times their own weight in water. It is used in emulsions, adhesives, and sealants. It is a gritty, abrasive white particle filler. A macroscopic particle of bentonite is composed of many thousands of stacked and/or overlapped submicroscopic flakes. 

Bentonite occurs commercially as powders ranging in colors and tints from off white to pale brown to gray depending on the cations present in natural deposits. It comprises natural smectite clays consisting primarily of colloidal hydrated aluminum silicates of the montmorillonite or hectorite type of minerals with varying quantities of alkalies, alkaline earths, and iron. It is insoluble in water, in alcohol, in dilute acids, and in alkalies. 

Bacterial Alpha-Amylase Activity, 789 Bacterial (PC) Proteolytic Activity, 811 Baking Soda, 355 Balances and Weights, 729 Balsam Fir Oil, 156 Balsam Peru Oil, 38, 574 Barium Chloride TS, 850 Barium Diphenylamine Sulfonate TS, 850 Barium Hydroxide TS, (S 1)114 Barium Hydroxide, 0.2 N, 856 Barium Standard Solution, 849 Basil Oil, Comoros Type, 39, 574 Basil Oil, European Type, 39, 579 Basil Oil, Italian Type, 39 Basil Oil, Reunion Type, 39 Basil Oil Exotic, 39 Basil Oleoresin, 391, 392 Bay Leaf Oil, 217 Bay Oil, 40, 575 BCD, (S 1)15 Beeswax, White, 40 Beeswax, Yellow, 41 Beet Fiber, (S1 )45 Beet Sugar, 400, (S2)35 Benedict s Qualitative Reagent, 850, 851 Bentonite, 41 Benzaldehyde, 456, 607 Benzaldehyde Glyceryl Acetal, 456, 607, (S1)60... 

White wines contain relatively large amounts of insoluble proteins that slowly precipitate from the solution (the initial protein precipitation begins during pressing). Most white wines are to deficient in phenolics, causing a quick and complete protein precipitation. Protein haze may be due to the fraction of residual wine proteins that have been rendered prone to precipitation by their interaction with reactive phenolics (from the grape, and also rarely from the cork). Bentonite removes different amounts of grape protein fractions (Moine-Ledoux and Dubourdieu 1999). 

Protein clouding in white wines seems to be a greater problem when the wine pH is close to the isoelectric point of the various protein fractions. This is due to the fact that bentonite will remove, preferentially, the most positively charged proteins. The electrostatic charge of various protein fractions explains the observable phenomena of not being able to stabilize certain wines with the use of bentonite alone, or only with excessive amounts that can strip the wine character. But the pi of proteins only partially explains wine haze formation. It is also important to note that other factors, as yet not clearly identified, can intervene. 

Other authors have searched for alternative treatments for the use of bentonites, particularly the yeast mannoproteins owing to the fact that a systematic improvement of protein stability can indeed be observed in white wines during aging on lees in barrels (Ledoux et al. 1992). Aged on lees, new wines become decreasingly... 

Protein levels in white wine have been reported by several authors and have been shown to differ by variety. Lee (1986) reported a range of protein concentration from 18 to 81 mg/L in 14 wines from different Australian regions and made from different varieties. Some of these wines appeared to have been fined with bentonite prior to analysis. Pocock et al. (1998) reported concentrations in unfined Australian wines up to several hundred mg/L. Hsu and Heatherbell (1987b) found a range of 19 4 mg/L in four different unfined white wines from Oregon, while a very large variation (20—260 mg/L) was noted by Bayly and Berg (1967). 

---