It has oftentimes been a subject of remark that wrought iron tubes employed in the production of sodium are never converted into cast iron, although the carbonate of soda from which sodium is distilled contains a large amount of carbon. M. Tissier, of Paris, has recently made some experiments in connection with thisj subject, and has ascertained that wrought iron is not affected in any way by the carbonate alluded to, even at a very high temperature. He tried the action of the carbonate of soda upon malleable and cast iron at the melting point of the latter, and found that while the malleable iron was not affected, the cast iron was deprived of its carbon and silicon, and converted into malleable iron. M. Tissier also operated ou gray pig iron containing six and a half per cent of silicon, and graphitic carbon. The iron was heated with an excess of carbonate of soda at a bright red heat for several hours. It boiled up, evolving bubbles of carbonic oxyd, and when this action ended, the iron was withdrawn and immersed in wator. The result was, that this iron, formerly so brittle, could now be forged under the hammer and welded ; its granular structure had disappeared—it had become fibrous crystalline. The action of the cai--bonate, as reported in the Le Technologiste Juillet removed all the sulphur and phosphorus from the iron, as well as the silicon. M. Tissier has only made experiments with small masses of iron; and although the results of his efforts are interesting as a matter of science, yet practically they are of little value, because the metal so treated, although changed from pig to malleable and wrought iron becomes too porous—it was full ofcavities. Something practically useful, however, may yet be derived from the discovery. It is for this reason we direct attention to it.
This article was originally published with the title "Conversion of Pig Iron into Steel and Malleable Iron"