Degasser Tablets

Product Description

D-Gas Tablets

GENERAL DESCRIPTION:

D-gas comprises a granual material strongly bonded and formed into a weighed unit with high surface area to volume ratio to ensure maximum contact area with liquid metal.

D-gas is used for degassing of molten copper and copper based alloys. In copper and copper base alloys, dissolved hydrogen and cuprous oxide combine to form water vapor by steam reaction. The solubility of hydrogen in copper and its alloy melts reduces as the temperature falls until the gas attains the solid solubility. The hydrogen which is expelled from solution tends to combine with cuprous oxide levels are very low after deoxidation, hydrogen may still be problematic and it is preferable to reduce it to negligible proportions. The easiest and most effective way of doing this is to bubble through the melt a stream of hydrogen scavenging gas which does not react with the alloy treated. D-gas units comprise a mixture of chemicals which, on contact with the molten metal, decompose to give a continous steady stream of non-reactive gas. Since D-gas is very carefully dried and packed, the gas bubbles contain very little hydrogen and are able to flush out that gas and carry it to the surface where it is lost to atmosphere

APPLICATION:

INSTRUCTIONS FOR USE:- Logas units are of annular shape, having a central hole into which a simple refractory coated and properly dried steel plunger can be inserted. a) Melt down under the cover of an approximate flux like FLUXIT. b) For degassing, Plunge the D-Gas units to bottom of the melt. Maintain this position till the bubbling effect subsides totally. This would ensure maximum contact time between evolved gas bubbles and melt and obtain good hydrogen removal. c) The degassing time should be at least 3 minutes. This is accompanied by a loss in temperature of 10-15 centigrade degrees. A correspondingly higher degree of superheat must therefore be allowed.