US1948235A - Electrolytic manufacture of iron and its alloys - Google Patents

Description

Patented Feb. 20, 1934 UNITED STATES ELECTROLYTIC MANUFACTURE OF IRON AND ITS ALLOYS Ernst Kelsen, Vienna, Austria, assignor to Kelsen Special Sheet Holding, S. A., Luxemburg, Luxembnrg, a limited company of Luxemburg No Drawing. Application March l'l, 1933, Serial No. 661,417, and in Austria April 22, 1931 2 Claims. (01. 204-1) Difficulties are met with in the manufacture of chemically pure iron by electrolytic refining owing to the anode material containing metalloids, such as sulphur and phosphorus, which are present for example when using cast iron scrap. The anodicsolution always takes place with a slightovervoltage, so that at least partial oxidation of the sulphur to S04-ion occurs. It is easy to satisfy oneself by analysis that this ion is present in such a refining electrolyte.

The iron raw material, however, is not the only source of sulphur, because both acid and water which must be added throughout the duration of the electro deposition, contains as a rule a 29 certain amount or Bot-ion, which also has to be removed.

It is desirable to remove the 804-1011 thus formed from the electrolyte, which, when manufacturing iron, consists mainly of ferrous chloride, with or without an additional salt, and which, when manufacturing alloys, consists of salts of those metals of which the alloy consists, also with or without an additional salt, preferably sodium chloride, because, in view of go'the considerable hydrogen overvoltage at the cathode, the SO4-ion undergoes partial reduction, gives up its sulphur content to the electrolytic iron. and thereby impairs the magnetic proper-,

anodes) containing sulphur, characterized in. 40 that the electrolyte contains besides the iron salt, or the salts of those metals of which the alloys consist, one or more additional salts where of at least one gives such a cation, that it gives an insoluble precipitate with 804-1011. Such an aadditionalsaltmaybeaddedaloneasacon ducting salt, or it may be added together with another conducting salt. 7

Conveniently, barium chloride or some other suitable -barium salt is added to the electrolyte as a conducting salt. The SO4-ion then forms an insoluble barium sulphate fwhich readily settles and may be removed from time to time by filtering the electrolyte.

It has heretofore been proposed in certain cases to use CaCl: as an additional salt in an 35 iron salt electrolyte. The purpose of. adding this salt was, however, quite different from thataimed at by the present invention. The object of adding this salt heretofore was either to improve the electrolytic conductivity or to work at temperatures near or above 100 centigrade, whilst, according to the presentinvention, the object is to remove from the solution practically the whole content of the SO-i-ion. For the first mentioned cases it was necessary to add considerable quantities of the salt to attain success, whereas for the purpose of the present invention,

a relatively small amount of such a salt is sufilcient;

I claim: g

1. In a process of preparing electrolytically manufactured iron of improved magnetic qualities from raw materials containing sulphur, the step of reducing the sulphur content of the electrolytically produced iron by adding to the elecg5 trolyte containing the iron-salt a salt of an alkaline earth metal which, possesses a cation which yields an insoluble precipitate-with Sol-ion, m an amount suflicient to completely effect such precipitation.

2. In a process of preparing electrolytically manufactured iron of improved magnetic qualities from raw materials containing sulphur, the step of reducing the sulphur content of the electrolytically produced iron by adding barium chloo5 ride to the electrolyte containing the iron salt in an amount sufficient to completely precipitate all of the sOi-ion.

ERNST KELSEN.