THE GOLDFIELDS.

Auckland Star, Volume XXXVII, Issue 226, 21 September 1906, Page 2

THE GOLDFIELDS.

KOMATA REEFS RETDEK £3664 FROM 1650 TONS. The return from the Komata Reefs G.M. Co. for the four weeks ended September 8, was £3664 from 1650 tons of ore. This return is not quite equal to the yield for August, although 50 tons extra were treated. At the same time the average value of the ore shows better than that treated for some months prior to August. The detailed, returns are as follow: —

Returns from 1900 to December. 1005 £183,260 0 0 ! I'eiiocJ euUiugJnnunry 27. 190 G. 1150 tons.. £2849 0 0 February 24, 1350 tons 2896 0 0 Mareu 2i, 1510 tons 2U29 0 0 April 21, 1620 tons 3152 0 0 May 19, 1720 tons 3400 0 0 June 16, 1710 tons 3320 0 0 July 14, 1680 tons 5531 0 0 August 11, 1600 tons 3736 0 0 September, 1650 tons .„„. 36tt4 0 0 Total to date ..„„, £212,546 0 0 Total dividends ..„,.„ £26,664 0 0 TREATING COMPLEX ORE. AN INTERESTING DEMONSTRATION. Any process that is calculated to convert complex ore into free milling must, naturally appeal to all who are interested in the mining industry. Consequently it is not to be wondered at that a number of Auckland gentlemen spent several hours yesterday at the American School Laboratory in Princess-street to witness a practical demonstration of the complex ore refining process, by Mr. W. E. C. Alexander, M.PJ.M. and M.E. The object of the demonstration was to prove in the presence of the visitors that it was possible to convert refractory ore into free milling; and this was undcj'ot edly done to the satisfaction of all present. Mr. Alexander said that the cost of treatment by his process was 8/9 per ton, and said he was willing to apply it to any class of ore, no matter how refractory. The ore submitted for the test was from Te Puke, and of poor grade, two fire assays being made prior to treatment, and the result at about 6.30 o'clock showed that under the process 94 per cent of the assay value had been saved. It should be explained that this is purely an ore refining process, and not a gold-saving one, because after the complex stone has been converted to a free milling condition, the bullion is then saved by the ordinary amalgamation process. The ore, however, after being converted to free milling, is in such a friable condition, that it is very easily treated, and, unless the gold is very fine, cyanide treatment should not b* necessary. What the process dees is to leave the gold in a clean condition by eliminating such matter as suclphur, arsenic, antimony, tellurium. Even where the gold ia very fine, the time required for cyaniding the ore after treatment by this process is very short, and the consumption of cyanide ia greatly reduced.

TREATING COMPLEX ORE. AN INTERESTING DEMONSTRATION. Any process that is calculated to convert complex ore into free milling must, naturally appeal to all who are interested in the mining industry. Consequently it is not to be wondered at that a number of Auckland gentlemen spent several hours yesterday at the American School Laboratory in Princess-street to ■witness a practical demonstration of the complex ore refining process, by Mr. W. E. C. Alexander, M.PJ.M. and M.E. The object of the demonstration was to prove in the presence of the visitors that it was possible to convert refractory ore into free milling; and this was undcj'ot edly done to the satisfaction of all present. Mr. Alexander said that the cost of treatment by his process was 8/9 per ton, and said he was willing to apply it to any class of ore, no matter how refractory. The ore submitted for the test was from Te Puke, and of poor grade, two fire assays being made prior to treatment, and the result at about 5.30 o'clock showed that under the process 94 per cent of the assay value had been saved. It should be explained that this is purely an ore refining process, and not a gold-saving one, because after the complex stone has been converted to a free milling condition, the bullion is then saved by the ordinary amalgamation process. The ore, however, after being converted to free milling, is in such a friable condition, that it is very easily treated, and, unless the gold is very fine, cyanide treatment should not tw necessary. What the process dees is to leave the gold in a clean condition by eliminating such matter as suclphur, arsenic, antimony, tellurium. Even where the gold ia very fine, the time required for cyaniding the ore after treatment by this process is very short, and the consumption of cyanide ia greatly reduced.

In order to demonstrate his process. Mr. Alexander erected a small plant in the workshop in Princess-street. Thfi ore before treatment simply requires to go through a stone-breaker reducing it to about the size of hazel nuts. In that condition it was fed into a specially constructed furnace, in the designing of which Mr. Chinnery Suggate rendered valuable as3istar.ee owing to his expert knowledge upon such matters. The furnace was fired with coke, and a heat of 1900 degrees was attained. The broken ore was placed in closed receptacles in the furnace, and then subjected to the action of equal volumes of carbon monoxide and hydrogen gases, which are introduced into the furnace without combustion. These gases were generated by passing dry steam through incandescent charcoal. The result is that the hydrogen acts on the sulphides, arsenides, teJlurides, bromides, chlorides, oxidss, and antimonides, etc., reducing them to the metallic state and combining with the sulphur, arsenic, tellurium, be-omine, iodine, antimony, etc., in them, as volatile compounds of hydeogen, such as sulphuretted hydrogen, eta. The carbon monoxide also combines with the oxides of the metals, reducing them to the metallic state and combining with their oxygen to form carbonic acid, which goes off (under control) together with the volatile compounds of hydrogen through an escape pipe, but where an ore contains valuable by products, these can be collected. None escape from this improved style of furnace, and a special feature of it ia that loss of gold by volatilisation in telluride ores ia entirely obviated. The length of time required for roasting does not exceed six hours. Yesterday, the furnace was charged at a quarter to 12 o'clock, and the process was completed under three hours. The ore when removed from the furnace was dropped into water, and when cool could easily be crushed with the fingers. Some of the raw ore was grand, and when panned off, only showed a very faint; colour in the dish. The converted ore when ground and panned off, gave a much beter show, thus proving conclusively that the treatment cleaned the gold thoroughly. The treated ore was then assayed most carefully by Mr. Storey, and gave the highly satisfactory result of 94 per cent of the fire assay of the ore. No intricate machinery is requisite for this process, the first crushing being in every case accomplished by a stonebreaker alone preparatory for the furnace treatment, and after that by stamps, they being preferable to grinding mills. The difficulty of carrying out this chemically perfect process on a continuous and commercial scale has hitherto been due to the unsuitability of the furnaces obtainable. This obstacle has now been overcome by Mr. Suggate'and Mr. Alexander, with the result that the cost of treatment on a large scale will be materially less than by any effective roasting process. Mr. Alexander stated that £2500 would put up a furnace capable of treating a fair quantity of ore, and the practical demonstration yesterday would seem to warrant the hope that the problem of satisfactory dealing with refractory ores ia approaching solution. A. WARDEN'S COURT. (By Telegraph.—Own Correspondent) I'AETROA, this day. Mr R, S. Bush, S.M., gmnted the following npplu-ations yesterday nt the Warden's Court. I'ueroa:—Hrmry I-rfinjidon, Sco- ! tin H.-ilin. Wniteknuri; W. 11. Rmett, timber warrant of 20 acrvs, for six months, near Patron: D. J. Young and othprs. permission to work the SUverstream claim Trlfn fonr ! men for six months; Rising Sun GoldmlnLng ', Co.. permission to work thp Rising Snn : claim with fonr men fr>r sii months; Auck- j '.and Bntirri erf Education, temporary reserve of two acres at Komata for educational purposes.