COMPACTS BASED ON PYROGENICALLY-PRODUCED SILICON DIOXIDE

摘要

Compacts based on pyrogenically-produced silicon dioxide and having the following physical and chemical characteristics: Outer diameter 0.8 - 20 mm BET surface area 30 - 400 m2/g Pore volume 0.5 - 1.3 ml/g Breaking strength 10 to 250 N Composition > 99.8 wt.% SiO2 Other constituents < 0.2 wt.% Abrasion < 5 wt.% Apparent weight 350 - 750 g/l. are produced by a method in which pyrogenically-produced silicon dioxide is homogenised with methyl cellulose, microwax and polyethylene glycol with addition of water, dried at a temperature of 80 - 150.degree.C and comminuted to a powder, optionally the powder is compressed into compacts, and heat-treated at a temperature of 400 to 1200.degree.C for a time of 0.5 to 8 hours. These compacts can be used as catalysts or catalyst carriers in vinyl acetate monomer production and ethylene hydration.