Mining in California Volume 13

Mining in California Volume 13

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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. 1896 edition. Excerpt: ...superintendent. Enright Mine (Quartz).--See Deakin & Taylor. Eureka Tellurium Mine (Quartz)---It is near Middle Creek, 2% miles W. of Redding, at 630' elevation, and contains 292 acres. These ores carry quite a percentage of tellurium, and considerable difficulty has been encountered in beneficiating them. Since our last Report. a new process plant has been erected for handling them. The ore is drawn from the tunnel mouth up an incline tramway to the mill, where it is delivered to the rock-breaker and crushed to walnut size, and then dropped into a drying furnace, with an incline hearth, to remove all moisture. The furnace is 5'x 20', with a hearth of iron plates, under which the products of combustion pass from the grate to the stack. The ore then is crushed dry, a 30-mesh screen being used, and elevated into an agitator, 8' in diameter, where chemicals (a secret solution) are intimately mixed with the ore. The pulp is then passed into two rotating, egg-shaped iron barrels with hollow trunnions. These barrels are 3'x 4' inside, and weigh 7,000 lbs. each; each contains 16 steel balls, 6" in diameter. After being charged the barrels are rotated from 4 to 12 hours, according to the amount of tellurides contained, but more especially with reference to the amount of coarse gold; the coarser the gold the longer the time required. The pulp is finally emptied into a steam filter, 4' in diameter, capable of holding 2 tons of pulp. The filter consists of 10-oz. duck spread over a wire gauze, through which the pulp is forced under 100 lbs. pressure of steam. The clear solution is passed into two 3'x 3'x 16' precipitating vats, lined with galvanized iron, while V the residue (pulp) is...
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Product details

  • Paperback | 364 pages
  • 189 x 246 x 19mm | 649g
  • United States
  • English
  • black & white illustrations
  • 1236849515
  • 9781236849519