THE EXTRACTION OF METALS FROM THEIR ORES.

Te Aroha News, Volume V, Issue 216, 20 August 1887, Page 1

THE EXT RACTION OF METALS FROM THEIR ORES.

Auckland, August 16. Pftoi-iv-. u f'.i."\VN~ lectured at the Auckland Jti-'ftnn' 'ust night before a largo and' interest.! -I audience on the above subject, j and lllualiulud his remarks by successful ! experiir outs. Professor Thomas presided. Professor Biown, at the outset, pointed out th.it although the combination of the I various me tab with the other elements presented ihe greatest variety, only a very limited number of compounds were likely to be found in large enough quanti-' ties to make it woith while to establish works 'oi the extraction of the, metal. For instance, the solubility in wax i vi a large number of metallic compio ii ' resulted in their being carried away !u (in , nn water permeating tho .soil, < while u 'i» .iL*\or an opportunity offered soluble coj.mh ..nds underwent reactions which resulted iu t lie formation of others which were insoluble 1 liit- general chemical law was illustrate I by the precipitation of numerous insoluble bodies.. Again, of tho insolublo metallic compounds only those which mo made up of common elements were likely lv be found in large quantities. As a matter of facfc the metallic ores con bitted mainly of oxides, sulphides, and carbonates, and the latter were .nearly all of thorn reduced to the state of oxide.s by heat, as in the case of the burning of limestone. The fact that Milphides can be transformed into oxides o> in some cases into the metals themseh. by roasting in the air was illush 1 1 1". I by the roasting of sulphide of silver, U.• metallic silver being left behind in i •u.jider.ible quantity. The action of carbi'i' monoxide in the reduction of metallic oxides was also explained and ill.i l.ited by several experiments. In conclusion the lecturer spoke of tho special u.oUiuds employed in New Zealand for tin. t I luotion of iron, gold, and silver, but he h I not time to treat this matter as fully as I:- 1 wished, and he therefore intimated tli if ho would have to postpone the remaintu i of his discourse to a future occasion. TheCk-iiinan, in closing the proceedings, said that their object should be to get the best process for reducing the ores at the Thames. One process had already been tried, the Lamonte process, but any person who kiiev ihe nature of the ores which had I to be ti of 111 1 < >( ! could have prophesied failure ior this h< m the ihst ; but there were other processes- which had not been tried, and their obj 01 was to get an experimental plant, so .1-1 to pi event such failures in futtue, and they should realise that this experimental p'.int would prove of great value to the v 'ioie community. He felt sure they wei all very thankful to Prof. Brown for the \ ry instructive lecture he had just delivezed. (Applause.) He had only now to annoiii't'c that the next meeting of the Institute would be held on Tuesday, the 29th in.st.ml. The assemblage then dispersed.