TREATMENT OF AURIFEROUS ORES. '

Otago Witness, Issue 1917, 17 August 1888, Page 12

TREATMENT OF AURIFEROUS ORES. '

The following from the New Zealand Herald of a recent date Will be tcrA with interest by all connected with mining pursuits : — Mr P. Ferguson, who went Home to raiße capital for the working of, the mines and battery owned by the New Bra (jold Mining Company, has written a Jebter dated Glasgow, May 20, from which we make the following extracts :— " Glasgow, May 20, 1888 —There is every prospect of my securing for New Zealand what I consider the best discovered process for saving gold and silver in ores-, however refractory. This process is being put.to the most 3evere tests on a hrge scale, and, with Only one exception, has given mosb satisfactory results. The difficulty experienced in this exceptional case is a mechanical one, and as the syndicate who own the process is composed of gentlemen of unlimited 'means (up to date they have spent over £70,000 in prosecuting their researches) and seem to delight in facing arid overcoming difficulties, I believe before this letter reaches you the process will be perfeoted, and bnt for the delay in the Premier ore arriving in London, I should bo on my way out with the said process in toy pocket. The s.s. Bayley is reported at Sfc. Vincent, and should arrive in London about the end of this monthr Fourteen days is the usual time taken before the ore is landed; the froisen mutton and other cargo being generally discharged first. Then two months will elapse bsfore negotiations are completed after the ore is treated, deciding on the most suitable machinery, development of the mines, &c. With regard to the machinery good progress has been made. I have had a machine made, and have it running at the works here. Ths mill is giving most satisfactory results, and will cost less than £100 It reduces dry ore to a fineness of 2500 holes per square "inch ; 10 tons per 24 hours, usiug 5-horse power. Wearing surfaces will not exceed 2d per ton, a-id hi.lng simple, castings are easily replaced. When everything is settled I think these mills will be adopted. I will very probably bring 10 or 12 ont. The past history of Auckland mining booms have all been shortlived ; it is to be hoped that the current boom will be a lasting one, and I see nothing to prevent it if the mining community but follow the example shown by almost every other successful industry, by employing chemistry and the best scientific knowledge iv the treatment of the various forms in which our gold and silver exist— the same course so strongly advocated by Professor Black, Hon. Mr

Larnach, Mr Gordon, and others, not forgetting the late Mr Kenrick. This sensible way of dealing with ores is exemplified by a, large going concern I am permitted to visit here as often as I choose. The same gentlemen with whom I am treating are the directors and largest shareholders. The ore is* brought from Spain. The mine is situated 30 miles from the shipping port, and before it reaches Glasgow it is turned over six times. The average assay value of the ore for years past is £2 10s 6d per ton, consisting of cv., 2 per cent., 16s ; s., 48 per cent., 16s ; pi., 1 per cent. 2s ; silver, loz, 4s ; gold, 15gr, 2s 6d ; iron, 10s— total, £2 10s 6d. Expenditure : Mining, 3s 6d ; cart carriage, In ; freight, 10s ; cartage, 3s ; grinding, Is ; salt, 2s ; coal, 3s 6d ; handling, ss ; water and washing, 2s 6d; iodide iron, &c., Is— total, £1 12 sod;— leaving a profit of 18s per ton on an output of 200,000 tons per annum. They have a regular staff of 50 chemists at the chief office here ; sometimes they have double that number. I could give many more examples in the iron and steel industry. ' Twenty years ago the furnaces were managed quite differently. Now a chemist just from the university can direct the workmen how and when to draw the furnace according to required quality. This is done by a quick system of analysis. Again, brewers trust to . the chemist to direct the reactions in .their business, also the dyers, print works, bleachers, &c. It will not surprise you, therefore, that I should do all in my power to interest the gentlemen with whom I am daily associated, so that we may command the best technical talent for Te Aroha goldfields, and I think that I can safely say that I have succeeded, for as soon as possible after the manipulation of the ore, arrangements will be made to send out the most efficient staff of experts from their works, including the technical master, the latter gentleman being very anxious to reside in New Zealand after reading and hearing so much about the colony .'*