Abstract: This disclosure relates to fabrication of quartz hollow cylinder with reduced bubbles using atmospheric control. An example horizontal rotating arc furnace includes a housing, supports, and a rotary union. The housing defines an interior configured to receive silica particles and electrodes that generate a plasma arc and includes a plurality of first ports on an exterior of the housing fluidly connected to the interior and supply pipes fluidly coupled to the first ports. The supports mechanically couple the housing to a drive system to provide rotational motion to the housing. The rotary union is coupled to the housing includes second ports to fluidly connect to a vacuum supply. The second ports are fluidly connected to the first ports via the supply pipes. The horizontal rotating arc furnace is configured to apply a vacuum to the interior of the housing via the first ports when the housing is spinning.

Abstract: A process for producing a synthetic quartz glass powder which is substantially free of carbon contaminant, for reduced bubble density and improved stability of articles made from the synthetic quartz glass during fusion molding by maintaining the synthetic silica powder in an oxidizing environment, e.g., an atmosphere comprising at least 3 vol. % ozone at a temperature of less than 1400° C., causing carbon containing compounds to be reduced to less than 10 ppm.

Abstract: A method of forming a carrier material suited to use in Fischer-Tropsch reactions includes forming a dispersion of first and second hydrated alumina materials in a liquid dispersant, such as an acid solution. The first alumina can be derived from an alkali aluminate, such as is formed in the Bayer reaction. The second hydrated alumina can be derived from high purity aluminum, such as via conversion to an alkoxide. The dispersion is spray dried to form particles which are heat treated to form a carrier material having low levels of impurities.