Silica reaction

As a result of these reactions, silica activity in the fluid increases with depth. 

After completion of the reaction, silica gel (ca. 100 mg) was added while stirring. The reaction mixture was filtered through Celite (ca. 300 mg) and washed with ethyl acetate (ca. 5 mL). 

Production. Silicon is typically produced in a three-electrode, a-c submerged electric arc furnace by the carbothermic reduction of silicon dioxide (quartz) with carbonaceous reducing agents. The reductants consist of a mixture of coal (qv), charcoal, petroleum coke, and wood chips. Petroleum coke, if used, accounts for less than 10% of the total carbon requirements. Low ash bituminous coal, having a fixed carbon content of 55—70% and ash content of <4%, provides a majority of the required carbon. Typical carbon contribution is 65%. Charcoal, as a reductant, is highly reactive and varies in fixed carbon from 70—92%. Wood chips are added to the reductant mix to increase the raw material mix porosity, which improves the SiO (g) to solid carbon reaction. Silica is added to the furnace in the form of quartz, quartzite, or gravel. The key quartz requirements are friability and thermal stability. Depending on the desired silicon quality, the total oxide impurities in quartz may vary from 0.5—1%. 

Keywords amine, surface-mediated reaction, silica gel, hydroxylamine... 

Procedures (1) refluxing in acetone solvent (2) cold aqueous reaction (3) sandwiched layer reaction, chromatographic plate coated with Kieselguhr G (4) sandwiched layer reaction, silica gel-loaded paper SG 81. Conditions Glass column (140 cm X 1.5 mm I.D.) packed with 1% GE XE-60 and 0.1% Epikote 1001 on Chromosorb G, acid washed, dimethylchlorosilane coated, 60—80 mesh. Temperature 215°C... 

The cracking of petroleum products is probably the most common dealkylation reaction. Silica-almnina, silica-magnesia, and a clay (montmorillonite) are common dealkylation catalysts.. ... 

These complexes are stable to the conditions of the Sonogashira reaction, silica gel chromatography (EtOAc/Hex), dilute TEA, KF in DME, POCI3, PSCI3, MCPBA, MMPP, Arbuzov conditions (neat (EtO)3P, 110°C), and Nal/acetone. Reagents that release HCl will require an acid scavenger to prevent premature deprotection. The 9-BBN chelate of amino alcohols has been used to selectively monoalkylate primary amines, a process that is often problematic because of bisalkylation. ... 

The main advantages of silica gel are that it has a high capacity for water, can be regenerated at a low temperature, and is not catalytic for sulfur conversion reactions. Silica gel (including silica-base beads) also has a high capacity for pentane and higher hydrocarbons... 

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