Phosphate Recovery Corp. v. Southern Phosphate Corp.

20 F. Supp. 153, 1937 U.S. Dist. LEXIS 1562
CourtDistrict Court, D. Delaware
DecidedMay 12, 1937
DocketNo. 1087
StatusPublished
Cited by1 cases

This text of 20 F. Supp. 153 (Phosphate Recovery Corp. v. Southern Phosphate Corp.) is published on Counsel Stack Legal Research, covering District Court, D. Delaware primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Phosphate Recovery Corp. v. Southern Phosphate Corp., 20 F. Supp. 153, 1937 U.S. Dist. LEXIS 1562 (D. Del. 1937).

Opinion

NIELDS, District Judge.

This is the usual patent infringement suit. ■ Plaintiff charges defendant with infringement of a patent to George A. Chapman and John W. Littleford, No. 1,968,008, issued July 24, 1934, upon application filed March 26, 1929, for “Concentration of Minerals.” Plaintiff’s ownership is proved by assignment from the inventors to Minerals Separation North American Corporation and by assignment by that corporation to the plaintiff. The sole defense is invalidity.

Problem in the Industry.

The principal source in the United States of calcium phosphate used as a raw material by the fertilizer and chemical industries is the so-called Pebble Phosphate Rock Field of Florida. Under an “overburden” of earth and sand varying in deptii from S to 25 feet lies a stratum or “matrix” of phosphate mineral varying in thickness from 3 to 12 feet. The business of the Florida phosphate industry is to mine this phosphate mineral and to remove from it the silica and clay. “Phosphate concentrates” thereby produced are sold to the fertilizer and chemical industries. The overburden is removed by huge scoops operated by powerful machinery and piled in long ridges. This leaves the stratum of phosphate material exposed. It is then mined hydraulically. This hydraulic mining disintegrates the stratum of phosphate ore by means of powerful streams of water. The mixture of ore and water is pumped to a “washing” plant through an iron pipe a foot in diameter. '

The phosphate washing plant separates the silica and clay - from the phosphate particles and screens out the coarser phosphate material. Much of the clay is washed out. A large proportion of the phosphate mineral is of such a size as to be easily separated from the gangue by washing and screening. About 50 per cent, of the phosphate is thus removed in the form of a finished product suitable for market.

The remaining 50 per cent, of the phosphate passes through the screens in the washing plant along with the major part of the silica and other impurities. Until about 1927, this finer material, known in the industry as “washer waste,” “washer tailings,” or “débris,” was regarded as unconcentratable and was sent to waste. Such washer waste was allowed to flow away frequently into pits from which phosphate mineral had been mined. The solids settled there. Such “dumps” are scattered over the Florida phosphate field. They contain many millions of tons of phosphate in the form of fine phosphate particles mixed with silica and clay. The loss involved in sending to the dumps 50 per cent, of the phosphate was fully understood. Unsuccessful efforts had been made to solve the problem of saving it.

Since 1927 plaintiff has solved this problem on a commercial scale by two new complementary methods.

One is particularly useful when both the phosphate and the silica particles are comparatively fine. This is the so-called froth flotation process. It is" not involved in this case.

The other method of separating phosphate particles from the silica particles in the tailings rejected by a washer plant is described in the Chapman and Littleford patent in suit. This so-called “tabling” method is particularly useful for the treatment of material which contains particles too large to be satisfactorily treated by froth flotation. Of course, it is possible by grinding to reduce the coarse material [155]*155to a size capable of being efficiently treated by froth flotation. Such grinding involves expense as well as loss of very fine material and should be avoided, if possible.

History of Patent in Suit.

The Chapman and Littleford file wrapper and contents and the decision of the Examiner of Interferences, dated January 29, 1932, show that the Patent Office considered no less than 18 patents and 6 publications disclosing the prior art before the patent in suit was granted. The following patents referred to at the trial of this suit were carefully considered by the Patent Office Examiners, who held that they did not negative the patentability of the Chapman and Littleford invention: Sulman, Picard & Ballot, No. 879,985; Cattermole, No. 777,273; (this acid patent is the companion to the Cattermole alkali patent No. 763,260 cited in this case); Sulman & Edser, No. 1,492,904; Broadbridge & Edser, No. 1,547,732; Trotter & Wilkinson, No. 1,795,100; Littleford, No. 1,780,022.

The Chapman and Littleford patent application was submitted not merely to ex parte consideration, but also to interpartes consideration in the Mason v. Martin v. Chapman and Littleford interference. Mason and Martin found themselves antedated by Chapman and Little-ford. They contested the patentability of the Chapman and Littleford invention. It appears in Mason’s and Martin’s motions to dissolve, and particularly in the decision about to be quoted, that the patentability of what arc now' claims 1 to 3 and 6 to 8 of the patent in suit was attacked.

The decision of the Examiner of Interferences contains the following passages:

“Broadbridge and Edser in their domestic patent, No. 1,547,732, and in their corresponding British patent, No. 171,155, describe their process as concentration by froth flotation. The domestic patent was cited against Martin during the prosecution of his application, and it is believed he then rightly contended that there is no disclosure therein of the formation of loosely bonded agglomerates and the separation thereof from gangue by agitative wet stratification.
“Without discussing the other reference cited by Martin in detail, and thus unnecessarily lengthening this opinion, it is held that Chapman and Littleford describe a process dissimilar to that disclosed by any reference Martin cites, and that the process of Chapman and Littleford is not anticipated by such references, whether taken singly or in any obvious combination.
“The patents to Elmore, No. 703,905, Cattermole, No. 777,273, and Darling, Nos. 763,859 and 795,823 cited by Martin as showing by comparison with the patents herein-before- listed that the processes of Martin, and Chapman and Littleford are entirely different and operate on different principles do not, it is believed, sustain Martin’s point. In neither the process disclosed by the party Martin nor that disclosed by the party Chapman and Little-ford, with the small quantity of oil used by each party, are shot-like granules, such as described by Cattermole, or a buttery and homogeneous mass, as described by Darling, or oil globules, as described by Elmore, formed. These patented processes are true oil adhesion processes; the processes of Martin, and Chapman and Little-ford are not. As Chapman and Littleford state, the oil coatings of the particles composing the loosely bonded agglomerates formed in the practice of theirs and of their opponent’s process are ultra-microscopic and have no effect in causing adhesion of one particle to the other.
“The motion of Martin to dissolve will be denied.
“As the basis of his motion to dissolve, Mason maintains that the invention defined in the counts is unpatentable in view of prior art. He refers to a plethora of patents and publications, including patents cited by Martin and above considered. * * *
“In plain and definite terms the counts of this interference define a process whereby phosphate, the mineral treated, is separated from gangue under the surface of water, which is to say a differential sinking process.

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20 F. Supp. 153, 1937 U.S. Dist. LEXIS 1562, Counsel Stack Legal Research, https://law.counselstack.com/opinion/phosphate-recovery-corp-v-southern-phosphate-corp-ded-1937.