THE RAVENSCLIFF REEF.

Marlborough Express, Volume XXXI, Issue 106, 9 May 1896, Page 3

THE RAVENSCLIFF REEF.

Through the courtesy of a gentleman who has, during the last few days, been visiting Havelpck, we have had the opportunity of a most interesting interview, and, when we say that the gentleman has until lately been a mining expert at the South African mines, Johannesburg, and has been specially engaged to superintend the Ravenscliff, Waikakaho, due weight must be given to his expressions. He gives his opinion that thousands of pounds have been absolutely thrown away m the erection of a plant for the purpose of introducing the Cyanide process, as the stone is not a Cyanide ore, and this process should never have been introduced for the precipitation of the gold it contains. The ore is, he states, a pyritical one, and any person conversant with Cyanide must be aware that it is simply useless using it for this description of stone. The old amalgamation process is the only discovered way of dealing with it, providing always that the concentrates are saved by f rewanners (oscillating tables), and it is a proved fact that from 84 to 90 per cent of the fire assay can be saved from pyritical stone by this method. He further states most emphatically that the ore is a good one, of this he is satisfied from the tests made by himself during the last week, and there is not the slightest doubt that the ill-success m the past has been caused by the stone being badly handled, and from the want of knowledge displayed by previous managers. The mine is now leased by Messrs Logan and Wearne, both miners, from the English directors for four years, and they are doing the correct thing by replacing the wet-crushing plant, m conjunction with the concentrating tables. It will be interesting information to our mining readers to know that the Cyanide process is not capable of dealing with a high percentage of pyrites, as the solution expends its strength upon the baser metal, especially copper (a large constituent of pyrites), and is therefore unable to precipitate the gold. It is to this cause, together with the constituent parts of the ore, which was being dealt with, not having been previously ascertained, that failure may be ascribed. The mine, with a stamper of ten heads, driven by Pelton wheels, will be m full work within three weeks, twelve experienced men having been engaged.— Guardian.