The Stamp Milling of Gold Ores

Voorkant
Scientific Publishing Company, 1897 - 260 pagina's
 

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Pagina 194 - Phœnix being a notable exception, the pyrites of the Otago lodes yield a very good grade of concentrates. There is, however, no chlorination or smelting plant in the province, and any concentrates obtained have to be shipped to Australia for treatment at a cost and delay proportionate to the distance. That fact goes far to explain the neglect of this part of the milling. Before concluding, it will be well to glance briefly once more at the two older mills. Both the Phœnix and Premier lodes carry...
Pagina 251 - A fault or dislocation. 4. (Scot.) Traveling road for miners in Edge coals driven on the slope of the seam. (Gresley) 5. (or Well) The troughs and catch-pits, whether carrying mercury or not, which are used to arrest escaping amalgam, etc. The word "trap" should be confined to the deep boxes unprovided with mercury, and the word "well" to the transverse troughs which do contain it. At Clunes the word "boxes" is used, while, elsewhere in Australia "ripples" is a term given to shallow wells as distinguished...
Pagina 191 - The explanation of the results above quoted is to be found in the fact that the mortars were not designed of a shape adapting them for amalgamation inside, and there was no opportunity given to the amalgam to collect out of reach of the falling stamps, but, on the contrary, the quicksilver added was subjected to a violent agitation which caused it to be floured — that is, broken up into a myriad of small globules. These last are readily borne away by the water, and, escaping with the tailings,...
Pagina 184 - The three mills whose figures are given in the comparative table which follows are fairly typical. The Phoenix battery at Skippers is one of the best known in New Zealand, and nestles at the foot of the snowy ranges of the Southern Alps.
Pagina 24 - H O ing used it returns it to the creek, together with the addition of a certain percentage of sulphuric acid, as sulphate of iron, derived from the contact of the water with the partially oxidized pyrites in the ore, under conditions favorable to a certain amount of solution. The water then passes on to the next mill, where its slightly increased acidity reduces the life of the screens from 80 to 73 days. This second mill in turn contributes its share of sulphates, which help to injure the screens...
Pagina 185 - Wire-cloth is chiefly employed, but when the supply runs short the ordinary round-punched Russia iron is substituted. The holes in the two cases are of similar size, but the number of them per square inch is 324 in the one case and only 140 in the other. The pyrites...
Pagina 193 - Of the fi ve only three are supplied with mercury. They are 3 inches wide and only ^ inch deep. The residues from the blankets are shovelled from one tub into a second, from which they are fed by a running stream of water into a berdan pan 4 feet in diameter. Instead of the ordinary ball a suspended muller, called the drag...
Pagina 193 - ... 3 inches wide, divided by three longitudinal partitions. They slope 1^ inches per foot. The blankets succeed each other in three equal lengths. The first or top row is washed every hour, the second every alternate hour, and the third every third hour. Then follow the copper amalgamatingtables, 9 feet long by 4 feet wide. The total length is subdivided by five wells, one each at the top aiid bottom, and three others at equal distances between the plates.

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