Crystal sand

Mordenite minerals vary in the ease with which they may be converted to the large port type by chemical treatment (20). The presence of Cmmm as in the Rome, Ore., mordenite should enhance the ease of the chemical conversion by providing greater access to the internal regions of the crystals. Sand (22, 28) reported that mordenite from Rome, Ore., can be easily converted to the large port variety by chemical treatment. Thus the... 

Silicon is also a silicate and the earth s crust is made of complex silicates containing—Si O Si O linkage. Silica (Si02) occurs in nature in many forms such as quartz, rock, crystal sand, sound stone, flint, etc. 

The reactor is constructed with a cylindrical colnmn and an expanded freeboard. The distributor is a perforated plate. An inert gas matrix composed primary of crystal sand, is used as the bed material. The blower supplies the inert gas for flnidization or the amount of air for partial combustion. A cyclone is used to collect fine particles. Sembbers serve to quench the off-gases and remove condensables that were withdrawn from reactors. 

Fig. 38.—Various forms of calcium oxalate crystals. A, styloids from the bark of QuiUaja saponaria B, rosette aggregate from rhizome of Rheum officinale C, raphide from the bulb of Urginea maritima D. crystal fiber as seen in longitudinal section in either the xylem or phloem regions of Glycyrrhiza E, microcrystals (crystal sand) isolated from the parenchyma of Belladonna root F, monoclinic prisms and G, twin-crystals from leaves of Hyoscyamus niger. All highly magnified.

Micro-crystals (Crystal sand)—Bellandonnae Radix, Cinchona, Stramonium, Phytolacca, Capsicum. 

The mineral zircon (ZrSi04) occurs in nature as component of acidic igneous rocks. Their weathering yields sediments containing small crystals (sand) of zircon and further heavy minerals. These deposits are resources for industrial production. 

This is the method used by the commercial software packages Crystal Ball and RISK . The method is ideally suited to computers as the description of the method will reveal. Suppose we are trying to combine two independent variables, say gross reservoir thickness and net-to-gross ratio (the ratio of the net sand thickness to the gross thickness of the reservoir section) which need to be multiplied to produce a net sand thickness. We have described the two variables as follows ... 

Boil the mixture gently on a sand-bath for 4 hours and then decant into a conical flask and cool. Seed the cold solution if necessary with a trace of a-methylglucoside. The glucoside separates as colourless crystals. When crystallisation ceases, filter the glucoside at the pump, drain, wash quickly with a small quantity of methanol, and then recrystallise from a minimum of methanol. For this purpose methanol of good quality, but not necessarily anhydrous, should be used. The a-methylglucoside is obtained as colourless crystals, m,p. 165°. Yield, 6-7 g. 

Silicon makes up 25.7% of the earth s crust, by weight, and is the second most abundant element, being exceeded only by oxygen. Silicon is not found free in nature, but occurs chiefly as the oxide and as silicates. Sand, quartz, rock crystal, amethyst, agate, flint, jasper, and opal are some of the forms in which the oxide appears. Granite, hornblende, asbestos, feldspar, clay, mica, etc. are but a few of the numerous silicate minerals. 

Plastic clays composed largely of poorly crystallized kaolinite but having small amounts of iUite, and at times montmorillonite, are widely used ia bonding mol ding sands, especially ia the United States. 

Sublimation.—A poition of the dry subsiam.c may be purified by sublimation. It is placed (2—3 gtamsj on a l.irge uatch-glass, which is heated on the sand-bath ovei a vcia small flame. The watch-glass is covered with a sheet of filter papei, which is kept flat by a funnel ]daced above. After five minutes or so pale yellow, needle-shaped crystals of anthraquinone will have sublimed on to the filter ptiper. 

Quarz-keil, m. (Optica) quartz wedge, -kiesel, m. quartz gravel, -kristall, m. quartz crystal, rock crystal. -lager, n. quartz deposit, -linse, /. quartz lens, -mehl, -pulver, n. quartz powder- -rohr, n., -rohre, /. quartz tube, -sand, m. quartz sand, -scheibe, /. 

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