Mining for Mercury

Sun (Auckland), Volume III, Issue 638, 15 April 1929, Page 8

Mining for Mercury

Workings of New Industry

ALTHOUGH backed bv British capital, the company which is exploiting- the mercury deposits in the Far .North Auckland district is purchasing most of its plant am material within the Dominion. Two catchment areas ar being dammed for water supply to aid the treatment o cinnabar.

rpHE operations of a company which is -now installing expensive plant to work several hundreds of acres of cinnabar deposit in the northern district, a few miles from Kaikohe, were described in a recent article, which revealed also that a start was made only after the potential mineral wealth of the land had been thoroughly tested. The construction of an all-w r eather road of metal and clay, and the harnessing of the water from two large catchment areas in the vicinity, indicate the confidence which Imperial Chemical Industries, Ltd., possesses in the project. The road has already

been called into heavy service for the transportation of machinery and material into the works. The retorts which are to be used in the extraction of mercury from the ore were recently brought in from Kaikohe railway station after being railed there from the ship’s side at Opua. These retorts, which were purchased from a well-known cement company will, it is anticipated, be supplemented by two others of a similar kind, to be manufactured in Auckland. One of the dams is now being used for water supply for the job, and the second is in course of construction. Bores for more water are also being sunk. A liberal water supply will be required for the effective working of the plant, for the intricate process necessitates a final cooling-off of \the vapours by their descent against a stream of cold water.

The manager, Mr. R. H. Goodwin, is a mining expert of world-wide repute. Before he arrived in New Zealand he was operating in var *?us parts of the world, including Indo-Chma and on the Austrian-Bulgarian border. His experience with labour costs on JO in foreign countries gave him a iaist impression of the labouring wage-rate in this country, and he was surprised to discover such a disparity between the price of the foreign worker and of the New Zealander. Treatment of Ore The cost of extracting the mineral from the ore will not be so heavy as in some of the overseas mines, however. The ore will be dug up m huge shovels, transported to the plant in small trucks and treated without crushing. It will then be heated by air sufficiently to drive off the inetal in the form of fume or vapour. This operation is carried out in the furnaces already described, which are to he supplemented by condensing apparatus and machinery for the removal of impurities. Before the works were started, endeavours were made to induce the local authorities and the Government to assist in building the road. It is a properly surveyed public thoroughfare, but its construction with blue metal foundation and proper surfacing out of public funds was not considered by the authorities to be justified. This caused disappointment among the company’s representatives, who were inconvenienced by heavy demurrage charges at Kaikohe through the road not being ready ,in time for bringing in the first of the plant. Developmental Possibilities The local appellation given to this offshoot of the big British firm —Kaikohe Development, Ltd. —was apparently considered sufficient inducement to local public assistance, but the local authorities look upon the concern purely as a private enterprise —however desirable might be the possibilities of developing its mineral wealth. If the weather remains favourable for outside working, the plant should be ready to start in the spring or early summer. Lack of capital has been the sole reason for the cinnabar deposits of the Far North remaining undeveloped. A syndicate purchased a large area of land from the Maoris about 30 or 40 years ago, but after a short while the finanae became exhausted, and the plant was abandoned. Remnants of the bricked-in furnaces are still to be seen near the Tdundations of the new machinery. As an adjunct to New Zealand industry the cinnabar treatment plant Is important. Other areas in the same district are known to be rich in mercury deposits, but it remains for the company now setting up its machinery to prove the extent of the mineral, which, when marketed at Home, realises something like £22 10s for a receptacle containing 751 b.