Degussa Aktiengesellschaft

Roland Reuter

Rudolf Schwarz

Gerhard Sextl

Peter K Kleinschmit

Hans Strack

Sabine Bartelt

Klaus Wilmes

Friedel Worch

Dieter Binder

Hans Hoffmeister

Ilona Sporys

Ilona Fuss

Powdered substances are compressed by a process wherein the powdered substances are enclosed in a flexible receptacle, the receptacle is enclosed in a pressure vessel and the space between the wall of the receptacle and the wall of the pressure vessel is pressurized with compressed gas.

Apparatus for the compression of powdered substances

Process for the compression of powdered substances

Heat insulator and method of making it

A preferably platelike form body for use as heat insulation, consisting of: a) a finely divided, powdery or fibrous material, b) a microporous casing and c) a gas and watertight casing. The form body is produced by optionally drying the powdery or fibrous material, optionally placing it into a microporous casing, optionally pressing it and then optionally drying it. Then, the powdery material is placed with the microporous casing into a gas and watertight casing. This gas and watertight casing is optionally evacuated and sealed.

Shaped articles for heat insulation

A monoclinic zirconium dioxide with an SiO.sub.2 content below 1.0% by weight is provided which is characterized by dendrite-shaped particles with an average grain size (d.sub.50 value) in a range of 0.5 .mu.m to 3.0 .mu.m and a specific surface (BET) in a range of 3 to 15 m.sup.2 /g. This zirconium dioxide is produced by thermally splitting zirconium silicate in a high-frequency- or medium-frequency induction melting furnace with sintering crust crucible, quenching the melt by blowing on a stream of melt with air and/or spraying it with water and leaching out the thermally split zirconium silicate with concentrated alkali lye at 100.degree. 200.degree. C. The zirconium dioxide of the invention provides a material with improved suitability for the production of zirconium silicate pigments of the host lattice type and inclusion type so as to provide for more color-intensive pigments.

Monoclinic zirconium dioxide, method of its production and use

A shaped body, preferably plate-shaped, for use as heat insulation, formed of (a) a finely distributed, powdery or fibrous substance, (b) a microporous casing, and (c) a gastight and watertight, metal-free casing. The shaped body is produced by drying a powdery or fibrous substance if necessary, optionally placing it into a microporous casing, optionally pressing and then optionally drying. Thereafter, the powdery substance is placed with the microporous casing into a gastight and watertight, metal-free casing. This gastight and watertight casing is optionally evacuated and sealed. Furthermore, a shaped article, preferably plate-shaped, for use as heat insulation, produced from (a) a finely distributed, powdery or fibrous substance with a water absorption capacity of 4 to 50% by weight at 23.degree. C. and 85% relative humidity, (b) a casing of two parts with asymmetric design which contains this finely distributed, powdery or fibrous substance, the first part of the casing being metal-free and concave in such a manner that it is completely filled by the preferably plate-like shaped article and the second part being metal-free or metallic and planar and connected to the trough in such a manner that a gastight and water-vapor-tight seal is assured and both parts having water-vapor-permeabilities between 0 and 0.2 g/m.sup.2 /d at 23.degree. C. and 85% relative humidity and gas permeabilities for N.sub.2, O.sub.2 and CO.sub.2 of in sum 0 to 0.5 cm.sup.3 /m.sup.2 d/bar at 23.degree. C.; the shaped article having the property of absorbing water up to an amount of 2 to 15% by weight without its thermal conductivity deteriorating more than 25%.

Form body for heat insulation and vacuum insulation panel with

Heat insulator and method of making same

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Darmstadt, Germany

Roland Reuter