PRESSLINGE AUF BASIS VON PYROGEN HERGESTELLTEM SILICIUMDIOXID, VERFAHREN ZU IHRER HERSTELLUNG UND IHRE VERWENDUNG

摘要

Pressed bodies is based on pyrogenic silica having the following physical-chemical data:… External diameter: 2 to 15 mm… BET surface area: 50 to 400 m<2>/g… Pore volume: 0.6 to 1.3 ml/g… Breaking strength: 50 to 150 N… Pore distribution: no pores of < 5 nm diameter… Composition: > 99% by weight of SiO2… Attrition: < 1.0%… Bulk density: 400 to 500 g/l,… are produced by homogenising pyrogenic silica with urea, methylcellulose and/or magnesium stearate, graphite and aluminium stearate with added water, drying the mixture at a temperature of from 80 to 120 DEG C, comminuting it to a powder, pressing the powder to give pressed bodies and heat-treating for a period of 0.5 to 8 hours at a temperature from 400 to 1200 DEG C.