Electric Smelting & Aluminum Co. v. Pittsburgh Reduction Co.

Citations

• 111 F. 742
• 1901 U.S. App. LEXIS 4992

Syllabus

<p>Patents—Infringement—Process for Reduction of Aluminum Ores.</p> <p>■ Tbe Bradley patents, No. 40-1,933 and No. 468,148, relating to a process for the reduction of highly refractory and nonconductive metallic ores in an unfused state by electrolysis, some of the claims having sxiecific rpforcm-o to the application of such process to the separation of aluminum from its ores, are not infringed, by the process of the Hall patent, Xo. 4(10,7GG, for the reduction of aluminum ores. The Bradley process consists essentially in passing an electrical current through a mass of ore, such current having a sufficient strength and intensity to fuse the ore-, and to effect its continuous and progressive decomposition, while the essential feature of the Hall process, which has given it great commercial i ¡¡hie, is the employment of a hath of fused cryolite, in which alumina readily dissolves. Such hath has a greater electrolytic stability ¡han the alumina, and the latter, when in solution, is decomposed, by passing through the mass an electrical current not having sufficient intensity to effect the decomposition of the bath, which is kept in a fused condition by the heat incidentally developed in the process of electrolysis, and used with repented charges of alumina. In such process there is not only a different employment of ingredients from that of Bradley, and an entirely new method of operation, but far better results are1 attained; and, conceding that Bradley was the iirsl to point out the method by which progressive fusion and electrolysis was made practicable, in view of the prior art and of the doubtful utility of his process, which has never been put into commercial use, his patents cannot be given a broad construction, as embodying a pioneer invention, to cover the process of Hall, which has superseded all others and resulted in a remarkable increase in the production and use of aluminum.</p>