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DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 51
Its capacity is from 40 to 50 tons per day. It was estimated that the minimum yield of the ground was $2 per ton, and from that up to $4.
Some prospecting was also done on a gold-bearing quartz-vein situated on the west side of the creek. A 40-foot shaft exposed 7 feet of vein matter, consisting of quartz and schists carrying pyritic sulphurets. An assay of an average sample is stated to have given a value of $9.55 per ton. Assays of the more highly pyritic portion (about 4 feet in width) showed $19.06 per ton, and it is supposed that this material can be concentrated to $60.
The Welborn (or Smith) mine, which is 2 miles west of the Silver Hill, carries similar ores.
The Conrad Hill mine is situated 6 miles east of Lexington. The country-rocks are silicified chloritic and argillaceous schists, striking X. 10°-20° E., and dipping 80° K¥. There are two systems of veins, one parallel to the strike of the schists, and the other cutting the same at various angles. The vein-matter is quartz and siderite, carrying chalcopyrite and gold.
A number of these veins have been opened and worked by three different shafts, the deepest of which, the main or engine shaft, is 400 feet deep.
The thickness of the ore-bodies varies in different portions of the mines from less than 1 to as much as 20 feet.
The method of preparing and treating the ores at the time the mine was in operation, was to partially sort underground, and then still further hand-cobb and pick on the surface, which product went to the copper works; the remainder was crushed and jigged and the heads added to the hand-picked ore above; the tails were counted as waste, and the middlings were sent to the stamp-mill and amalgamated, where the tailings from the battery were again partly concentrated by buddies and blankets, and the concentrates sent to the copper works.
The treatment for the extraction of copper at first was to smelt the roasted ore in a shaft furnace for matte, from which, after re-smelting, black copper was obtained and refined. Smelting wTas superseded by the Hunt and Douglas wet process. The crushed roasted ore was subjected to a bath of protochloride of iron, for the conversion of the insoluble copper minerals to the soluble chloride; after leaching, the copper was precipitated by metallic iron and then refined. The residues were milled and amalgamated in order to obtain the gold.
JUNES IN MONTGOMERY COUNTY.
The mines of this county are situated in the northern-central and northwestern parts, along the range of the Uharie mountains.
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