Californian Method of Amalgamating Gold.

Cromwell Argus, Volume I, Issue 12, 26 January 1870, Page 3

Californian Method of Amalgamating Gold.

Much of the gold is caught or amalga • mated in the battery. The stamps fall into an iron box or mortar, into which an ounce of quicksilver is thrown for every ounce of gold supposed to be in the quartz. If the rock is crushed fine in the battery, two-thirds or three-fourths of the gold may be caught there, leaving one-third or one-fourth that escapes through Mie screen. After leaving the battery, the pulverized quartz in most mills runs down over copper plate which has been washed over with diluted nitric acid, and then rubbed with quicksilver till the whole surface is covered with amalgam, and when the plate is covered with gold it operates more effectually than when the quicksilver is fresh. Gold unites moro readily with gold amalgam than with pure quicksilver. The copper plate which is the bottom of a trough or sluice, may be fifty or a hundred feet long. Between the copper plates in many mills are troughs, in the bottom of which are laid coarse blankets, or gunny bag, or even cowhide with the hair an, and the grain against the stream. Gold amalgam and sulphurets are caught in the rough surface of the blanket, gunny bag, or hide, which must be taken up and washed at intervals, which are usually not more than half-an-hour long. The shaking-table used in amalgamation is a long box with traverse divisions containing quicksilver. It is set horizontally, and is shaken longitudinally, receiving from 100 to 200 short jerks in'a minute. By these jerks the pulp is throwu back upon the quicksilver.

1 Pans' are coming into use slowly in the gold quartz mills—at least in some of the new ones lately erected in Grass Valley. Rustel says of pan amalgamation that it is 1 at present the most perfect gold manipulation,' and by it' gold is extracted as close as 95 par cent, of the fine assay'—that is if thero are no salphurets. (Nevada and California processes.) The general opinion [a that_ from 20 to 40 per cent, of the gold is lost in the ordinary processes.