Method for producing expanded glass granules and expanded glass granules and the use thereof

摘要

The invention relates to a method for producing expanded glass granules. To this end, starting materials are provided, comprising 80% to 95% glass and 5% to 20% sodium silicate hydrate having a water of crystallization content between 1 and 2 wt %, in relation to the solids content. After the glass is ground, the starting materials are mixed, the ground starting materials are granulated into raw granules, and the raw granules are mixed with a release agent, the mixture comprising the raw granules and the release agent is heated to a processing temperature. In a first partial step, the pores on the surfaces of the particles of the raw granules are closed, and in a second partial step, the water of crystallization is dissolved from the sodium silicate hydrate and caused to thermally expand, whereby the particles of the raw granules expand and form the expanded glass granules.

主权项

1. A method for manufacturing a swelling-glass granulate, comprising the following steps of:
preparing starting materials, including 80% to 95% glass and 5% to 20% of a water glass hydrate with a proportion of water of crystallization portion of between 1 and 2 wt. %, relative to a solid proportion, in which the water glass hydrate acts as a swelling agent and no further swelling agents are prepared as a starting material; grinding the glass; mixing the starting materials; granulating the ground-up starting materials to a raw granulate; mixing the raw granulate with a parting compound, the parting compound exhibits a portion between 10% and 40% of the mixture including the raw granulate and the parting compound; heating the mixture including the raw granulate and the parting compound to a processing temperature that is at least as high as the lowest sintering temperature of the glass reduced by the water glass hydrate and less than the melting point of the glass, in order, in a first partial step, to close the pores at the surface of the grains of the raw granulate and, in a second partial step, to release the water of crystallization from the water glass hydrate and bring about thermal expansion, in which the grains of the raw granulate swell up and form the swelling-glass granulate; and cooling of the swelling-glass granulate.