CORRESPONDENCE.

New Zealand Herald, Volume XXXIV, Issue 10419, 17 April 1897, Page 6

CORRESPONDENCE.

WET AND DRY CRUSHING. TO THE EDITOR. Sir,—ln last Saturday's issue you pnbliA the result of an interview with Mr. R. BHunt, general manager, New Zealand Er ploration Company, when reference wu made to the experiments in wet crushing now being carried on by the Crown mines, Karangahake. To outsiders it would appear that the management of Crown mines had made a wonderful discovery, which, with characteristic philanthropy and total disregard of self, they are placing at the disposal of the mining community generally, free gratis. Iu this respect they make a virtue of necessity, because there is nothing new about wet crusto' with the dilute solution of cyanide in the mortar boxes. This process has been in M operation at Johannesburg and Califoinis, from time to time, during the past Sn years, with varying success. Comin? nearer Home, it was worked about three years Ul at Waiorongomai, by Mr. fl. H. Adams,wh , was the tiret person in New Zealand to try it on a large scale, with 20 head of stainpenAt that time the Waiorongomai plant wf visited, and the process carefully inspec'w, by one of the Crown Mines Company's em , ployees, and it is more than probable tW this is the source from whence to* Crown Mines people borrowed the notion of wet treatment by the cyanide pro , cess. Exception must also be taken W the statement that the new departure will revolutionise milling operations ia '>"• Ohinemuri district. It does not follow thai because the wet system may prove succes* ful in the case of the Crown Mines ore, thai it will be equally etik-acious in the treatment of ore peouliar to other mines. There Ml no two mines alike so far as the character of ore is concerned. Success cannot pessiM) attend the scheme where the ore subjected to treatment is accompanied by clay or earthy matter of any description. Then a high percentage of slimes would be formed, aud the** present an obstacle to the wet treatment of ore by the process under d> cus3ion that has never yet been overcomein any mining regiou in the world. At Johannesburg'upwards of £109,0!)0 lias beeo expended by English capitalists in connection with the sliine difficulty, under thi supervision of practical men, who hare ' world-wide reputation as skilled metallurgists, and according to latest advices tb.* problem still remains unsolved, in t'M strictest sense of that term.—l am, etc., Cyaxicido.