Author Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt:...from concentration might be treated by the "oil process" or any number of processes. It is needless to say that the coarse silver can be concentrated. At present there are six new concentrators in the camp, three in operation and three nearly completed. One plant is designed to treat the tails by cyanide; the other by raw amalgamation. It is sincerely hoped that those in charge will make public the results of their operations. Whether they are successful or not, the knowledge of their results will be beneficial to the camp. SAMPLING.. The bulk of the shipments from the camp have gone to the custom smelters of New Jersey, and as the ore is exceptionally rich, and special facilities are required in the sampling, it is almost invariably sampled at the public sampling works. Shovel sampling is preferred to mechanical samplers. Here in the presence of representatives from buyer and seller, the sacks are weighed in lots of ten, by a public "sworn weigher." The ore is crushed, rolled, and re-rolled, the nuggets of silver being picked out by hand between each handling. The nuggets are weighed and deductions made. These are usually sold to the custom refineries as a separate transaction. The finely-crushed and thoroughly-mixed material is now completely sampled four successive times. The smaller samples are screened, and the metallics are subjected to a further grinding in small pebble mills. The four samples vary widely in their values, in spite of all precautions. Cobalt and nickel are not paid for by the custom smelters in the States. The ore carries no gold. Silver is the only determination necessary in most cases. This is determined by the combination method, wet and dry, on all ores carrying arsenic in quantity. The nuggets are melted in la...