Douglas Island news., 1899-05-31
The Douglas Island News
4 New Process.
Seattle Mining Record.

The Pelatan-C -Clerici process of ex- tracting gold and silver from ores IS one of the latest, and has been proven one of the best, methods for treating concentrates, tailings, etc. It IS class ed as an electro-metallurgiCal i'm provement on the regular cyanide pro- cess. The present system, generally adopted consists in the treatment ot the previously crushed ore, in circular tanks, with a cyanide solution, in the presence of bath of mercury and un- der the influence of an electric current.
 In general the tanks are built nine feet in diameter and five feet deep The bottom of the tank is covered with a copper plate, over which is bath ot mercury. This copper bottom is con- nected with one pole of the electric current, which, through it is connected to the mercury bath, thus making the latter he cathode.
 A vertical shaft, having a series ot arms and stirrets, fastened to iron plates, is suspended to the tank in such a manner as to revolVe in plane removed only a few inches from the mercury bath. This shaft, and through it the iron plates, is connected With the iron conductor from the electric generator, and these plates become anodes. The ore being crushed to the desired fineness and mixed with about an equal weight of water is run into the tank, the shafts and stirrets being kept all the time in notion A certain amount of salt is then added, depend ing somewhat on the character of the ore, and the electric current is turned on.
 The ore in this condition is kept in agitation for a given length ot time, generally three or four hours, after which the required amount of pOtas- sium cyanide is also added, and the agitation continued until the eXtrac- tion of values is completed. The pulp is then discharged through a valve just above the bath of mercury, and the vat is again ready for the new charge. Ali ter certain number of charges have been passed through the bottom, the amalgam strained from it, and the cop per plate scraped for the amalgam adhering to its surface. This in brief is the general method of procedure. The advantages claimed for the Pelatan- Clerici process over all other processes are as follows: l-Greater range of ore adaptable to treatment. 2-Posslblllty of treating cIayey and slimy ore not adapted to percolation-tiltration me thods. 3-Saving Of very large per centage of the silver as well as the gold from the ores. 4-RecOvery of the gold in the form of amalgam instead of the difficult compounds resulting from the zinc precipitates. 5-The recovery of coarse gold as well as fine, which can not be done by either the cyanide pro cess or by chlorination, except great expense for solvent, and greatly in- creased time required.
 On the best proofs that the claims made by the inventors of this process are based on sound facts is demon strated by the great success which has met it's introduction at the Republic mine.
 The ore in this mine is peculiar one and while containing very high values, was not profitahly amenable to treatment, either by the regular cya- hide process or by pan amalgamation, both of which were tried and failed. The ore is of a taIcose nature, imper- vious to filtration when crushed down to size sufficient to liberate the gold, and of such a dense character when not crushed fine, as to defy the solvent action of the cyanide solution.
 The best extraction by the cyanide process on this ore did not exceed 5 per cent. of the gold alone, with none of the silver, while by pan amalgama- tion not more than one-third of the values were extracted. The published reports from the mine for the last three months show a saving of 90 per cent of the assay values by the Pelatan- Clerici process, which has enabled the mine to become one of the large divid-
 end payers of the Northwest.
 MT. Mi ichael Okosh, of New Whatcom, ] NLrnnl nnrnn Ia Dnr,nlnc IclnnH lnct