THE BLACK SAND PROBLEM.

Otago Daily Times, Issue 13652, 23 July 1906, Page 6

THE BLACK SAND PROBLEM.

WHAT ITS SOLUTION MEANS TO OTAGO. Many methods have been from time to time suggested for the extraction of gold and other valuable minerals from the black sand which k so frequently met with in alluvial and gold dredging claims, but so far the problem set. has not been successfully solved. In most of the dredging fields in Ola jo tho black sand is to be found in twisidorablo quantities, and assays mr.de from iin; o to time by competent experts have shown that the sand is generally rich with gold. Recently a firm of English bullion-refiners (Messrs .lohnson and Son. of Loudon) intimated to the New Zealand llovernnient its willingness to purchase black sand and other similar concentrates obtained from dredges and alluvial washings. When ibis intimation appeared in the press several dredge proprietors and others forwarded parcels of black sand lo Messrs Johnson and Sons and to other firms, and the returns obtained are said to bo in .some cases very profitable indeed. One return, it is repotted, was equal to £30 per ton of black sand. The question is one that is naturally exciting a good deal of interest. A gentleman largely concerned with tho gold" dredging industry, in conversation with our mining reporter, said: "That a great quantity of tho very finest gold gels over the tables and is washed away with tho black sand in dredging is very generally recognised. All black sand is, of course, not as valuable as the samples which were recently sent to London, hut there is reason to believe that many claims where the black sand is plentiful will turn out exceedingly ncli if tho black sand tan be successfully treated at a reasonable cost. Suppose," said the gentleman in. question, "that instead of the black sand being worth £30 per ton it is worth £15 per ton, and that, a dredge can dredge up and save 10 tons per week, it will be readily admitted that this would mean an important element in the mining industry throughout the colony. A return of 10 tons per week at £15 per ton is equal, roughly speaking, to £75"0 per allium. Such lieing the case, dredging and saving black sand would be more payable than the present process of trying to save the gold. The value of much of our black sand is, of course, still problematical, but if it should be found profitable, what an immense impetus will lie given to the gold dredging indusirv in Olago. Claims that have been worked out for their gold could be dredged for their black sand contents. It is not to bo presumed that where the richest gold was obtaired that the richest black sand is to l>e had. Tho claims likely to prove most productive in the saving of gold from black sand will be those on the Ciutba River, round Cromwell, where the Rise and Shine. Rising Sun, Oltilha River, Alpine No. 2, Morning Light, and Riley's lieaoh dredges arc rmgaged; also in places further up the Clutha River. Then further down there, is a great stretch of alluvial flat and river from Olyde to Alexandra, also on the Manuherikia River, stretching for miles up to Chatto Creek—.il! Pkelv dredging ground. The district around Roxburgh is also to be reckoned' with. If the prospect nf-black sand dredging can I» carried on successfully it would open up a now era for Olago. It is not merely chimerical, but is almost an established faot. At (lore. Mr G. M. Thomson is, it is understood, erecting a large plant for the treatment of black sand to be saved from the dredge.? on the Wa.ika.ia, Waimuinu. and WaiVaka fields. The sand from these fields is said to also contain platinum, a very valuable melal. It i.s not too much to proi.ihe.sy, according to our informant, that the saving of black sand is going to revolutionise the mining industry of this province anil put now life into the mining community. There is," ho continued, "going to be ■no ' liooin,' but the black sand inilustry is going to be such thai Otago will become the wealthiest nrovinco in the whole colony." The West Coast has also black sand, and tho people there will no doubt also waken up to its great value shortly. Inquiries made from tho secretaries of the Rise and Shine and Alpine No. 2 Companies show that the assays made locally of samples of black sand from their respective claims have given excellent results. From a sample from the Alpine No. 2 claim assayed bv Mr D. B. Water*, assayer at the Ofago School of Mines, cold was extracted equal to Z°m lMwt 2?.gr per ton. Samples sub. mittcd from the Ri.se and Shine Company'' claim gave varying results. The most favourable was that, from No. 5 sample, which gave results equal to B<lwt. Hgr of gold and 3divt 22gr of silver per ton.