EMPIRE MINING COMPANY, PARK CITY, UTAH,
The property owned by this company is said to consist of fifteen loca-tions of fifteen hundred linear feet each, and one of three hundred feet, all situated in the Uintah Mining District, Summit County, Utah, and known as the O'Brian, Clara Davis, Silver Treasure, Prince Oscar of Sweden, Little Maud, Solid Muldoon, Inflexible, Celeste, McKay, Chal-lenger, Corr, Thunderer, Jennie Powers, Thunderer Tunnel, New Found Treasure, and Special Payment lodes. They are "said to cover, or adjoin, the mother lode of the district, about 1200 yards westerly from the well-known Ontario mine. Their altitude is about 8000 feet above sea-level. The Eastern office of this company is at 52 Wail street, New York City. The principal work done has been on the Clara Davis claim. We con-dense as below from a report by Professor William P. Blake: "This claim, 1500 feet long on the course of the lode, with 100 feet on each side for working purposes, is in Parley's Park, about thirty-five miles from Salt Lake City, and a mile and a half south of Park City. The claim is adjacent to the Ontario, being 2900 feet from the west line of that property. There is ample evidence that the Empire Company has the same vein as the Ontario. The hanging-wall of porphyry is separated from the vein by a clay gouge or selvage containing pebbles worn by the attrition of the walls. This, together with the structure of the vein, shows that the vein occupies a cleft or fissure, and also that it is deep-seated. It is a true fissure-vein of great extent in length, and, practically, as regards working, of unlimited depth. Its direction is nearly east and west, with a southerly dip of 63° to 65° on the surface, and a steeper dip of 70° below. I have no doubt it is upon the same fissure as the Ontario, and of similar origin.
"The vein consists in part of quartz and in part of argillaceous and feldspathic material. It is not wholly charged with ore, the pay-streak occupying only a part of the fissure, as also in the Ontario. In width, this pay-streak varies from eighteen inches to three feet." The openings consist of one main engine shaft and two levels; shaft 245 feet deep, vertical, and not on the dip of the vein. The latter is there-fore reached from the shaft by cross-cuts. The first cross-cut is at a depth of 100 feet from the surface, and the second, at 200 feet from the surface. From the points of intersection of these cross-cuts with the vein, levels have been extended each way, east and west. The 100-foot level extends 100 feet east and 105 feet west; being, therefore, 205 feet long. The 200-foot level has been driven 121 feet east, and 123 feet west, being 244 feet long. These measurements were in October, 1879, and the work has been progressing since that time. The quantity of milling ore developed in October was, according to a statement of Mr. E. B. Wilder, about 8000 tons, worth, at $35 per ton, the sum of $280,000. "The vein is favorably situated for mining, being in a salubrious, tem-perate region, with an abundance of timber and water at command." There is no statement made in these reports as to whether the mine has produced any ore, though Mr. E. B. Wilder estimates as above that there are 8000 tons of ore in sight, having a value of $35 per ton. Prof. Blake makes no estimate of the ore in sight.
THE EMPIRE MILL. The Empire Mining Company awarded the contracts to furnish the machinery for its mill to Messrs. Griffith & Wedge, of Zanesville, Ohio. The design and plan of the mill, as shown in the accompanying supple-ment, were made by W. H. H. Bowers, Mechanical Engineer, of Salt Lake City, Utah, who represents Messrs. Griffith & Wedge on the Pacific coast. Every thing connected with the mill will be first-class. Its estimated cost, including machinery, buildings, grading, mason-work and material to complete the same, ready to crush ore, will be about $250,000. That our readers may realize the magnitude of this mill, we will state that the ma-chinery weighs over 1,200,000 pounds, and the item of freight alone, from Zanesville, Ohio, to the mines, is over $26,000.
The following is a detailed description: The mill has 60 stamps of 750 pounds each, which will run at ninety drops per minute, with a fall of eight inches.
The batteries (dry crushing) will reduce 90 tons of ore every 24 hours.
It will be furnished with two large rock-breakers, two revolving dry-kilns, twelve self-feeders, and three revolving furnaces for desulphurizing and chloridizing the ore; each cylinder 60 inches in diameter and 24 feet long. They will be capable of treating all the ore reduced by the mill.
There will be 36 Union combination amalgamating-pans, 18 Belding settlers, two pans for cleaning amalgam, with retorts and melting fur-nace. Four thousand feet of gum belting will be used, of various sizes, varying from four inches up to 30 inches broad.
The power to run the mill consists of one 450 horse-power engine, automatic cut-off, condensing pattern, with six boilers of 75 horse-power each.
The building is 260 feet long, measured from ore-house to pan-room, and 272 feet from boiler-house to furnace-room.
The mill is of the pattern known as dry-crushing and chloridizing, and is expected to work the ore to 90 per cent or over of the fire assay.
The process of treatment is as follows: The ore is delivered from the mine to the mill by cars, which are loaded in the workings of the mine below the surface, hoisted to top of shaft, and thence run on tramway 200 yards to the mill. The ore is then shoveled into the rock-breakers, from which it passes, by gravity, into the revolving dry-kilns. The latter deliver it into a hopper, from which a car can readily be filled and con-veyed by the several tracks arranged for it, and dumped into the self-feeders. The self-feeders supply the stamps uniformly, and every way better than is possible by hand. After being crushed and passed through the 40-mesh screen, the ore is conveyed to the elevator on top of build-ing and, from there, a long line of conveyors delivers it into the roasting and chloridizing room, where it is equally distributed to the three furnaces.
After treatment in the furnace-room, the ore is again put into cars, and taken to the amalgamating-room, where 3000 pounds of it are charged into each of the amalgamating-pans. After being thoroughly amalgamated, it is discharged into the settler, where the silver is finally separated from the ore in the form of amalgam. From the settler, the amalgam is taken to the retort-room, and the pulp in the settler, being now worthless, is allowed to flow out and down the canon. The amalgam is retorted, and the resulting silver is melted down into bars weighing 130 pounds, and in this form it goes to the mint, or other refineries.
Messrs. Griffith & Wedge are constructing several other mills, but of smaller size than the one above described.
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