GOLD POLICY FOR OTAGO

Otago Daily Times, Issue 21542, 14 January 1932, Page 8

GOLD POLICY FOR OTAGO

MODERN METHODS URGED OTAGO’S VAST RESOURCES That a definite, scientific policy of gold production should be adopted by the Government in respect to the Otago goldfields was strongly advocated by Mr W. Stuart Wilson, of Wellington, in the course of an interview with a Daily Times reporter yesterday. Mr Wilson declared that at present the' system of gold production in this province was very much out of date, as was illustrated by the fact that the last mining handbook issued by the Government was more than 25 years old. If developed on proper lines, the Otago goldfields, he maintained, should be made to produce more gold than they had ever done in the past. The present time offered a wonderful opportunity, he added, for the Otago Expansion League, the Chamber of Commerce, the Manufacturers’ Association, and other bodies to solve not only the unemployment problem in Otago but in the whole of New Zealand. Scientific methods were needed, and the best brains in the community should, he insisted, help in bringing about this very desirable result. “During the past few months,” Mr Wilson said, “ I have visited several gold-mining enterprises in Otago, and I am sorry to note that primitive methods are in use, similar to the machinery and methods in vogue in the sixties. In fact, some of the machinery is a direct legacy from that period, as it has been bought second-hand by the present operating companies, after years of exposure to the weather, and in spite of the serious drawbacks, comparatively successful results are being obtained. The old miners with these appliances recovered about 60 per cent, of the gold, and the present-day miners are not doing any better. Profits are being made, and this fact alone shows how rich the gold-bearing areas must be when the recovery is so low. If modern methods were used with their usual high percentage of recovery it is obvious that very greatly-enhanced profits will be the result. In all these cases it would be of the greatest advantage if the operators coujd avail themselves of the services of a mining engineer who could examine the properties and make a recommendation on which they could approach some financial organisation sponsored by the bodies mentioned above. SURFACE ONLY SCRATCHED.

“My visit to various parts of Otago convinced me that there yet remains many millions of pounds worth of gold to be won from the various fields, both old and new. In one valley alone of approximately 180 chains by 20 chains boring has proved in about one-half of the area that there is £1,500,000 worth of gold in this one small block alone. I have been over the large conglomerate deposits in the Lawrence district, and seen results from pannings that make me believe that gold is lying there to the extent of many millions of pounds. The pioneers who made Otago famous have, in my opinion, only scratched the surface of these enormous deposits. Surely it only remains now for investigation and the adoption of modern methods to make available the vast stores of loeked-up gold in these various areas which entend from the Bluespur in the north- down through Wetherstones, Forsyth, Waitahuna, Glenore, and Adam’s Flat. 1 was intensely interested to see at Wetherstones Flat on the Golden Crescent claim the early construction stages of an experimental plant being put up, by means of which this conglomerate area is to be thoroughly tested. From what I saw there of pannings from the bottom layers, there seems every prospect of very interesting results from the experimental plant, which may lead to the establishment of several mills of very large capacity in which thousands of tons of ore may be crushed daily. “One of the minerals in this conglomerate is iron pyrites, which, for the past 70 years has been thrown away. Recent investigation by Mr George W. Thomson, mining engineer, has confirmed the fact that'iron pyrites carries locked Up in itself gold invisible to the naked eye of not less than one ounce to the ton, while other samples taken by others of whom I heard range through 1 loz up to 30oz per ton. The lloz sample was taken by the late Mr Herbert Cox, an eminent mining engineer, as far back as 1879. Nothing to ray mind illustrates the conservatism of our Government and the miners, the former of whom must have known this for the past 50 years. “ Another property in Otago has shown by assaying that some of the heavy material collected in the sluice boxes, and was considered by the miners to be of no value (as on panning it showed no gold) contained gold to the value of 70oz to the ton. This also has been thrown away for the past 50 years. These instances, I think, confirm my contention, and the sooner we have these mining areas under the supervision of some authority with modern experience, the better it will be for the country. The control of mining in New Zealand and Otago in particular, by the Government has not been, in my opinion, all that it should be, and the sooner such interested bodies as the Expansion League, the Chamber of Commerce, the Manufacturers’ Association, and others exert pressure for the purpose of bringing this about the easier it will be for the country to meet its national obligations.” LATEST METHODS OF RECOVERY.

Air Wilson said that the recovery of gold in any of the quartz mines in Otago was probably not more than 00 per cent., whereas in other and _ more progressive countries it was a point of honour that the gold recovery should run to 95 per cent,, and might even possibly approach 08 or 99 per cent. A mill superintendent who failed to attain this figure would, in all probability, he called upon by the management to give sound reasons for his failure. Modern methods included the sliming of the entire ore to such a fineness that probably 90 per cent, of it would go through a 200 mesh screen. This screen was equivalent to 40,000 holes to the square inch. The ore reduced to this state of fineness was then in a suitable condition for treatment by the cyanide process with its very high recoveries. In many gold mills abroad amalgamation as practised here was entirely dispensed with, and full reliance placed on the cyanide process. A new method called the flotation process was being introduced as an accessory to the cyanide process for the purpose of extracting the mineral content of the quartz (of which there was from one to five per cent, usually, although it would at times be very much greater). This effected such a clean recovery of the mineral and its gold contents that the balance of the ore so treated could he thrown away as being too poor to be further dealt with. This meant that the amount to be treated by the cyanide process was about 5 to 10 per cent, of the ore, and that approximately only 10 out of every original 100 tons had to be dealt with by the cyanide process, thereby considerably reducing treatment costs. It was by thus taking advantage _ of modern technical methods with a high efficiency and cheap costs that the gold mining industry occupied the high position it did in South Africa, Canada, and the United States, where gold mining had been reduced to almost an exact science, and mining engineers were regarded and treated as belonging to the aristocracy of brains and not as ap-

peared to be the case in New Zealand, little better than a superior type oC workman. “ It is of interest to note that thcne> are a number of men, all experts in their various professions,” Mr Wilson concluded, “ who are financially interested in two very good properties in Otagc, and are well aware of the very backward state of mining generally in Otago, and are taking proper steps to modernists thoroughly the working of their properties, giving particular attention to a thorough preliminary testing of the areas. Thousands of pounds are being spent in preliminary testing before arsr approach is made to the public, whidh. will,then have placed before it full particulars which ishould enable investors to realise that the proposition, although a mining one, has many fewer riskls attached to it than some of the propositions offered hitherto—in fact, {halt it may almost be called an investment. Of these two properties one has already been thoroughly tested, and the other is undergoing a close mining and metallurgical investigation with a view to applying the latest modern processes, ao that"Otago in a abort time, it is hoped', will begin to rank with these other progressive countries. At one of theae properties a method of excavation is tjo be introduced which, although highly efficient and long-established in other countries, will be new as applied i)o gold mining in New Zealand.”