OUR BLACKSANDS

Otago Daily Times, Issue 22352, 28 August 1934, Page 8

OUR BLACKSANDS

TO THE EUITOB Sißj—Some time ago, in a letter to you, I gave some details of the blacksands met with by most of our alluvial gold miners along our sea beaches and rivers. I pointed out the assay value of these sands ag given by the Otago School of Mines and by the Dominion Laboratory in Wellington. This assay value does not indicate free gold, but gold that requires cyaniding or other chemical process to extract it. Samples from Westland show that at present prices of gold the values there run about 10s per ton.. The Westland blacksands are already so fine that the gold-bearing part of them might cyanide without any further grinding. Here and there among them will be found a small amount of magnetic blacksand, mostly shining but of no value for gold. This would not interfere with the cyaniding of the fine part that has the assay value. .Every dredging claim and every sluicing claim along Westland must be washing down many tons of this fine blacksand daily. Material just as fine is regularly saved at the quartz mines for cyaniding. There seems no season, therefore, why dredges and claims should not collect and treat all that now goes overboard or down through the sluices. At the dredges and claims cyaniding plants would be necessary. Once erected these plants might run steadily while the claim .or dredging area lasted, and would absorb men from Waitaki dam or wherever else unemployed are found. The director Of the Dominion Laboratory tests samples free if the locality is mentioned. It each dredge and claim were to save a sample —a half-pound or so —and get assay value it would make the value definite for each locality concerned. A small testing plant to trv a few tons might be erected here and there by claims combining and learning what might be necessary to put the matter underway. Best methods of collecting the blacksand would also require studv. It might be necessary for the Minister to make certain adjustments and «ee to satisfactory starting. On some of the Canterbury beaches a very fine blacksand was worked .for gold. it might be worth testing. for working by unemployed. Otago and Southland black, sands are, however, a different problem. —I am, etc., D. Ross - Coal Creek Flat.