Abstract: Extremely high solids content silica dispersions are useful for forming green bodies of near net shape as compared to the shape of the bodies after sintering. The green bodies are particularly useful for sintering to form low impurity-containing crucibles for single crystal silicon production.

Abstract: A process for continuously rendering finely divided, pyrogenic silica hydrophobic at low temperatures in the presence of a hydrophobicizing aid such as aliphatic alcohols having from 1 to 3 carbon atoms. The process of rendering silica hydrophobic is conducted at temperatures of from 60.degree. to 350.degree. C., and more preferably from 80.degree. to 150.degree. C., over a period of from 2 to 5 hours, and more preferably from 3 to 4 hours. The hydrophobicizing agents are known organohalosilanes and the preferred hydrophobicizing aid is methanol. The hydrophobicizing aid is used in amounts of from 2% to 15% by weight, and more preferably in amounts of from 2% to 10% by weight, based on the weight of silica used.

Abstract: The invention relates to a process for continuously hydrophobicizing pyrogenic, finely divided silica, in which the waste gases are fed back to a mixing chamber upstream of the SiO.sub.2 reaction flame.

Abstract: An apparatus for transporting sheet material of the type having perforated marginal edge portions comprises a base adapted to receive and support the sheet material with the base having upstanding ratchet toothed stanchions positioned about its periphery. A cover bearing a handle has latch means adapted to receive and operatively couple with the upstanding stanchions to allow the base, cover and sheet material contained therebetween to be easily hand carried. The base is provided with upstanding pins positioned to register with the marginal edge perforations of the sheet material and guide flanges mounted to the base guide the sheet material into proper position atop the base.