The Stamp Milling of Gold Ores
Description:... This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt: ...it. The blanket washings are very poor. The North Cornish mill is not in the town of Ballarat, though in the mining district of that name, but at Daylesford. The plant consists of 50 stamps, and the rate of drop varies from 70 to 75 per minute, the height of the drop being 8 inches. The depth of discharge or issue is extremely irregular. When starting with new dies or false bottoms the top of the die is approximately level with the bottom of the grating and the depth of discharge is practically nil, but as the dies wear down (they are 4 inches deep) the issue in Near the famous Canadian lead, which yielded so many of the large nuggets. creases to a maximum of a little over 3 inches. The mill crushes 90 long tons per day, or 2,450 tons per month. The amalgamation is effected by methods similar to those described as in use at the Star of the East. Scarcely 11 per cent. of the amalgam obtained comes from the mortar boxes. Much the largest proportion is derived from the skimmings of the wells and in the blanket sands. The latter are treated by Eerdan pans, of which there are six. The tailings from the Berdans go to a Frue vanner for after-treatment. This is a comparatively new mill, the oldest portion being five and the newest two years old. The quantity of ore in sight in the mine is such as to have led to the consideration of a further addition to the number of stamps. The mine has paid large dividends for alongperiod.f Notwithstanding these facts the mill is miserably incomplete. Although very favorably situated and having all the fall required for an automatic arrangement of its parts, it is unprovided with rockbreakers or self-feeders. In the feeding of the 50 stamps there are employed upon each shift 5 men at 30 shillings per week, ..
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