CONCENTRATNG SILVER ORES[From Town and County Journal.]

Te Aroha News, Volume III, Issue 156, 29 May 1886, Page 7

CONCENTRATNG SILVER ORES[From Town and County Journal.]

Journal.] Ix a latter in continuation of this subject, Mr W. G. Gibson, writes the Silver Age :—: — '• When quoting from American authorities, I intended to say that ores containing in bulk 802 or lfloz of silver to the ton of ore, were brought up to 500oz or GOOoz by concentration. In continuation, therefore, of the subject as applied £0 fotidy ores, I may state that I have had thousands of tons of lead and zinc ores washed from an unmarketable grade up to a good paying point, simply by subjecting them to the action of running water on tables suitably inclined, the stuff being occasionally moved to permit of the regular action of the water. I quote this not that it could or should be done here, but merely to show that where running water is abundant by what simple means a valuable article could be turned to commercial account. I believe that electricity will ultimately be found applicable to the economical separation of gold and silver fiom ihe bbanes n e metals.and gangue. At this moment the Silver Age has come in with Mr Worth's letter on concentration. That letter of itself is sufficient to demonstrate the necessity of such a process. I am not aware that Captain Handcock's machinery, howover perfect for copper, ig the best for silver-lead ores ; but in any case there are several known machines in use which do that class of work perfectly, requiring no handwork after feeding the crushers or stampers, and giving out a return of lead ore, however poor to start with, which gives on smelting 75 percent, of metallic lead. The particular machine to be adopted is a matter of detail, the broad fact remains that the work can be perfectly dope ; the water csn be caught for re-use at a loss of 20 per cent, each time of useing. As regards the treatment by water of other classes of ores than lead ores, it will be a matter of study to find out the method that will be most effectual. "Wbereever 0 difference of specific gravity exists, the different gravities will separate, and it may be in some kinds of ore, that the middle or light stuff may contain the value. Experiments properly conducted and results carefully assayed will soon give the solution. I had to find it out myself in ores in limestone formation, mixed galena, blende and calamine. Amalgamation might in some cases be applicable ; also electricity. To the full developement of the field and a realisation of its mineral treasures such work is an absolute necessity. "VV. G. Purnamoota