Saint-gobain Vitrage

Saint-gobain Emballage

Daniel Abriou

Patrick Garnier

Jean-Jacques Gaudiot

Michel Coquillon

Alain Dugast

Benoit Beghin

Celia M Tangari

Processes and apparatus for the production of hollow microspheres by thermal expansion of glass particles including the thermal treatment of extremely small glass particles whose dimensions are less than 50 micrometers and, preferably, less than 35 micrometers or even 20 micrometers, which include a fluidizing agent. This technique makes possible the production of extremely small glass microspheres under satisfactory yield conditions. Also, the hollow microsphere products produced by these processes and apparatus.

Apparatus for production of hollow glass microspheres

Production of microspheres having a very high silica content produced from a starting glass whose silica content is less than 80% by weight, with the remainder being essentially made up of boron oxide and one or more alkaline oxide(s). This starting glass is reduced into fine particles by grinding, optionally mixed with a fluidizing agent, and then passed through the flame of a burner at a temperature at least equal to 1500.degree. C. to form molten hollow microspheres which are suddenly cooled to form solid hollow microspheres. The microspheres produced thereby are recovered and contacted with a dealkalization agent to increase the silica content thereof to at least 92%.

Production of high silica glass microspheres

Moulds for glass making and use thereof

Production of glass microspheres

The invention relates to a process and apparatus for producing hollow glass microspheres. According to embodiments of the invention, particles of a soda-lime-silica glass containing slight amounts of sulfur compounds are suspended in a gaseous current and expanded in a burner, at a treatment temperature at least 100.degree. C. above the working temperature at which the specific type of glass constituting the treated particles is made from its raw materials, such as sand, lime, sodium carbonate, sodium sulfate, and others, depending on the particular type of glass. The process makes it possible to increase the yield of the transformation of the particles.

Process for producing glass microspheres

Growing community of inventors

Gagny, France

Daniel Abriou