THE HAURAKI GOLDFIELDS

Auckland Star, Volume LXI, Issue 56, 7 March 1930, Page 6

THE HAURAKI GOLDFIELDS

POSSIBILITIES IN FERTILISER MAKj» G

(To the Editor.)

Without any doubt the remarks niadebv "Auriferous" in your issue dated March 4 Ji, respect to a new industry and to the wealtl obtained in the deposits of ore exwtiijv ; the Thames goldfleldd are substantially ° rect. Iron pyrites is a great deterrent' to tho successful extraction of gold and silver from the ore, and, further, a still greater deterrent to the . successful concentration of ones. Its presence in such abundance associated with copper, lead and zinc has prevented our metallurgists up to the present from bein« able to successfully deal with this cViss of ore' The processes available have not enabled tlieni to separate the various metals after concentration, and to this , fact the cause of faihn-n is due. The processes used have been mechanical and hydraulic, both of which dependaSll specific gravity for the separation of the metalliferous content of the ore from the quartz. Tho specific gravities of the various metals do not differentiate sufficiently to. enable their separation from one another. Ev tho co-ordination of ' fertiliser, mamifaetiu'e. with that of mining, the various metals can be separated, and. further concentrated, and the iron pyYites then becomes a .source of sup. ply of sulphur for sulphuric acid manufacture: Every ton of superphosphate manufactured contains from Gcwt to 9cwt of dilute sulphuric acid, depending on the class of phosphate rock .used. Connected with the manufacture' of fertiliser are , processes that will extract every?' thing of value in the ore contained in the. Hauraki . gokllields. FERTILISER ENGINEER. ■