Moore Filter Co. v. Tonopah-Belmont Development Co.

• Decision Date: 04 November 1912
• Docket Number: 1,612.
• Citation: 201 F. 532
• Parties: MOORE FILTER CO. v. TONOPAH-BELMONT DEVELOPMENT CO. [1]
• Court: U.S. Court of Appeals — Third Circuit

201 F. 532

MOORE FILTER CO. v. TONOPAH-BELMONT DEVELOPMENT CO. ^[1]

No. 1,612.

United States Court of Appeals, Third Circuit.

November 4, 1912

Gifford & Bull, of New York City, for appellant.

William Houston Kenyon and Harold Binney, both of New York City, for appellee.

Before GRAY, BUFFINGTON, and McPHERSON, Circuit Judges.

BUFFINGTON Circuit Judge.

In the court below the Moore Filter Company, the owner of patent No 764,486, granted July 5, 1904, to George Moore, for a filtering process, filed a bill charging the Tonopah-Belmont Development Company with infringement thereof. On final hearing that court, in pursuance of an opinion reported in 195 F. 530, dismissed the bill on the ground that infringement was not shown. Thereupon the complainant took this appeal.

As applied in the present case, the patent concerns the process of filtering metal-bearing slimes, and is known as the Moore process. The respondent's filter is for the filtration of like slimes, and embodies the Butters process. Both processes utilize the cyanide ore treatment, and the question before us is twofold: First, does Moore's process involve invention? and, second, does the respondent's Butters filter make use of the Moore process? The cyanide ore process came into use about 1887, and is the real foundation of the tremendous increase of gold production in the last two decades. It is now the prevalent method of treatment. In it the ore is first crushed and then placed in tanks containing a solution of cyanide of potassium. This solution percolates through the crushed pulverized mass, and, being a solvent of gold, carries off such gold as is subjected to its action. This is called 'leaching,' and any crushed ore through which percolation took place was termed 'leachable.' For example, if the ore treated was of such a character that, when crushed, it was reduced merely to the condition of sand, then the recovery of its metal by the cyanide solution might be effected by two methods. In the first method the cyanide solution would be poured on a bed of sandy crushed ore and be allowed to percolate through it. In its passage the solution dissolved the metal and passed off as a clear liquid to zinc boxes, or other well-known means of reclaiming metals in solution. This very simple method was called leaching. The second was decantation, wherein the crushed sandy material, after having been agitated in the cyanide solution, was permitted to settle, so that the clear liquid containing the dissolved metal might be decanted. Thus, so long as the crushed grain was so sandlike as to permit leaching, or would settle quickly and completely enough to permit decantation, reasonably satisfactory results were reached by the cyanide process with rich ores; but even with these the treated ore thrown on the dumps often contained large in the aggregate, though small per ton unleached metals. This was due to the fact that the solvent did not and could not penetrate the coarse ground particles. If, however, the ore was crushed finer, to permit the more intimate action of the solution, a pasty mass, called 'slimes,' was formed, which was unleachable.

The result of this was that great quantities of treated ore went to the dump heap, and while laboratory filtration methods showed the presence, and indeed the extraction, of such metals, yet no one devised any commercial means or process by which this metal-laden dumpage or slime could be avoided or utilized. As a value-containing, but unavailable, feature these ore dumps occupied a relation to gold and silver mines like that of a slag pile to a blast furnace or a culm bank to an anthracite mine. The proofs show the acute recognition of this grievous waste and the vain efforts of a great industry to avoid it. Thus in the Engineering and Mining Journal, under date of October 8, 1892, in an article on 'The Cyanide Process in South Africa,' by Charles Butters and another, it is said:

'Another difficulty frequently encountered in the application of the cyanide process is the treatment of 'battery slimes'; i.e., the very finely divided material produced during the crushing, and which has a tendency to accumulate in pasty masses. These either resist the penetrating action of the cyanide or retain the dissolved gold during the leaching operation. No satisfactory method of breaking such material has yet been devised. The evil may be lessened by mixing the slimy tailings with clean, coarse sand.'

An editorial in the same Journal, dated April 15, 1893, says:

'After a certain amount of experience with any process, its weak points are seen, and opportunities for improvements present themselves. To this rule the cyanide process is no exception. One of the great difficulties experienced in this process, or, indeed, in any lixiviation process, is the treatment of the slimes of an ore otherwise well suited to reduction by the method. They pack upon the filter, forming beds impermeable to the solution, and, even if mixed with large quantities of coarser material, are rarely attacked, although laboratory experiments will show that their precious metal contents are extremely soluble. Of such material the Robinson Gold Mining Company, of South Africa, operating one of the largest cyanide plants on the Transvaal, has accumulated 60,000 tons, and the management has long despaired of treating it successfully, as the gold would not amalgamate, nor would the cyanide permeate the mass, if it were charged into vats. The average assay value was between $7 and $8 a ton; but the fineness, it is estimated, is such that it would pass a 225-mesh screen.'

The same Journal, on August 11, 1894, contains an article on 'The Cyanide Process in the Transvaal Mines,' which says:

'One of the great bugbears of the cyanide men on the Witwatersrand has been the treatment of slimes, by which is meant the very fine, or, in the case of free milling ores, the clayey, portions of the tailings. Many suggestions have been made for the treatment of these; but the only really practical scheme, so far, appears to be to allow them to dry thoroughly and by screening or otherwise to reduce them to a fine powder. This powder is thoroughly mixed with sand tailings, and the mixtures will usually percolate fairly well.'

In an editorial in the same Journal, in speaking of the cyanide process, it is said:

'Undoubtedly the process is well adapted to certain ores, but these appear to exist in but few localities, and we have yet to learn how to extend the use of the process to more common material.'

In an article on that process, contributed by Virgoe to the same Journal in 1894, he says:

'Filter presses have been tried in South Africa, but without satisfactory results, owing to their cost and the power required to work them. No mechanical means have yet been devised for the satisfactory separation of pulp and solution in the case of poor leaching ores. Such an invention would revolutionize the metallurgical world as far as the wet reduction of ore is concerned.'

Commenting on this article, a correspondent in September, 1894, wrote the Journal: 'Regarding the leaching properties of the ore or tailings to be treated, I am quite in accord with Mr. Virgoe, for badly percolating material (such as battery slimes) is quite the greatest bugbear of the cyanide man.'

The following year (1895) Charles Butters, writing to the Journal, said:

'The treatment of slimes is a question of importance, as at present there are many hundreds of thousands of tons of unleachable material lying useless on the hands of the various companies on the Witwatersrand.'

And not only was the problem recognized and the need felt, but the agitation of it continued for years. In 1898 the same Journal, after discussing the various efforts in the Transvaal to treat rejected slimes, says:

'Speaking generally, about 75 per cent. of the tailings from the Witwatersrand mills have been treated by cyanide in the usual practice, leaving about 25 per cent. to go into the slimes pit. There is, therefore, a large accumulation of these slimes, besides those which come from current working. What proportion of the old heaps can be treated at a profit is yet to be ascertained; but it seems possible that an appreciable addition to the gold output may come from this source hereafter.'

In the same year, referring to the Australian mines, the Journal says:

'A great number of experiments are at present being conducted on the Kargoorlie ores. Nearly all known processes, and several never before heard of, have their advocates. Of course, some valuable knowledge will be gained by all this experimenting, and just as surely a great deal of very expensive machinery will in a short time be consigned to the scrap pile. * * * As yet the finer slimes have not been successfully treated on a large scale; but some one of the ingenious adaptations of the agitation or filter-press processes, now in the experimental stage, will undoubtedly solve the problem.'

Indeed, the whole matter was summed up four years later, when, in an article in the Journal of July, 1902, on 'A New Treatment of the Slime Problem in Cyaniding Talcose Ores,' a writer, Stackpole, says:

'Any metallurgist can appreciate the obstinacy of these sticky masses of mud, which, no matter how treated, would take almost a prohibitive length of time to percolate. Although experiments show that over 90 per cent. of the values in the clay is soluble, the ordinary methods only permit an extraction of 50 per cent.'

The first suggestion for the solution of this world-wide problem is found in the Journal of December 5, 1903, being a communication from George Moore, wherein he described the process for which the patent in suit was issued to him the year...