PUDDLING. This process has been explained under IRox manufacture. In stead of heat, electricity is now brought into play to effect the object, namely, the decarbonization and purification of the metal. A great economy in the conver sion of the cast into wrought meta/ seems about to be effected in our iron works, by the application of a current of voltaic electricity to the crude iron in a state of fusion, whether on the hearth of the blast furnace, on the fused pigs in the sand, or on the metal immediately on its being run from the finery furnace ; the voltaic force of from 50 to 100 pairs of a power ful Smee's battery being previously ar ranged to act upon the whole train of the metal. This process, for which Mr. Ar thur Wall has recently obtained a patent, is founded upon the well-established fact, that when a compound is subjected to an electrical current, its negative and posi tive elements are detached from one ano ther. Crude iron contains more or less carbon, sulphur, phosphorus, arsenic, oxygen, and silicon—bodies all electro negative in relation to iron, which is else tro-positive. When the impure iron, as
it flows from the blast furnaces, is sub jected during its cooling and consolida tion to a powerful stream of voltaic elec tricity, the chemical affinities by which its various heterogeneous components are firmly associated, are immediately subverted, whereby, in the case of crude iron, the sulphur, phosphorus, &c., which destroy or impair its tenacity and malleability, become readily separable in the act of puddling.
The pecuniary advantage of this pro cess, in respect of saving of labor and waste of material, has been estimated by competent judges at from five to ten dollars per ton.
The effect of electrising iron is display ed in a singular manner by the conver sion into steel of a soft rod, exposed in contact with coke, for a few hours, to a moderate red heat.