Decision on sulphur exploitation soon

Press, Volume CXIV, Issue 33463, 19 February 1974, Page 10

Decision on sulphur exploitation soon

(New Zealand Press Association) AUCKLAND, February 18. A decision on the viability of extracting sulphur from the deposits at Lake Rotokawa, near Taupo, is likely to be made in the near future by joint investigators, Fletcher Mining and Exploration Company, Ltd, (a member of the Fletcher holding group), and Gulf Resources and Chemical Corporation of Texas.

An associate director of Fletcher Holdings, Dr J. S. Watt, said that initial results from the latest experimental drilling programme, using geothermal steam, had been sufficiently encouraging to justify further work. More drilling is now under way, and tests on these later holes should decide the future of the sulphur extraction scheme, he said. Original experimental work on the recovery of liquid sulphur by the Frasch process was completed late in 1972. Using the Frasch process pipes are driven into the deposit; hot water is forced down one pipe and into the sulphur which is melted. The molten sulphur trickles back to the bore and is forced up another pipe by compressed air. The process is used widely

overseas, but geothermal steam has never been used before. Dr Watt said there had been no work on the deposit for several months after the original experimental work while test results were assessed in the light of the world sulphur supply, the price situation and the financing of further work. In October last year the partners agreed to restart experimental drilling . using different methods to settle some technical problems, and to give further assessment of commercial viability. It is the initial results from this programme that have spurred the current drilling programme.

Dr Watt said that the oil crisis and increasing freight costs made the development of local raw materials like sulphur even more important than when the investigation programme was started in 1971.