THE LOCKWOOD-McGUIRE PROCESS.

New Zealand Herald, Volume XXV, Issue 9096, 3 July 1888, Page 6

THE LOCKWOOD-McGUIRE PROCESS.

A few days ago we stated that a patent had been taken out for the LockwoodMcGuire combination process for the extraction of gold and silver, and other ores. The inventor of this process, Mr. Alfred A. Lockvood, is now in Auckland, , and has made arrangements to construct a furnace and erec, the other machinery for working his syste ; at Onehunga, so as to make a trial on > la i'er scale than he has hitherto been able i; do. Mr. Lockwood has been on the Thames and Coromandel goldfields since 1867, and has a large experience in all the operations connected with gold mining. For five or six years past he has been re.siding at Karangahake. For the last two years he has devoted himself to experimenting in the different methods of treating quartz by roasting, and at last he believed that he had found out a plan which enabled him to save all the gold. He came to Auckland, and stated what he wanted to do to Mr. Joshua Jackson. No one was prepared, however, to go into the matter, and to assist in erecting a furnace. Several processes are now being tried, and those who can go into these matters are pretty well engaged. It was suggested to Mr. Lockwood that before returning to the Thames he might see Professor Brown, Professor of Chemistry, who ; for several years past, has given a large amount of attention to the problem of utilising our ores. Professor Brown listened to Mr. Lockwood's statement, and commenced an experiment. An ordinary reverberatory furnace was constructed, and also one on the principle advocated by Mr. Lockwood. A trial of some stone from a claim at Karangahake was made at each. The result from the reverberatory furnace was nil, while Mr. Lockwood's process produced at the rate of 1640z of bullion to the ton. In Mr. Lockwood's process -the stone is placed in a square ■ iron furnace, in alternate layers of wood and quartz until the furnace is filled. It is then fired from the bottom. During the process of roasting steam is injected on the top, and as the heat increases steam is injected in the flue, where condensing chambers are formed. At a certain stage the upper condensing chamber is closed, the condensing flue is opened, allowing the fumes to enter the furnace again through under the fire bars. During the process everything is closed that would admit oxygen. The prooess takes five hours. No fluxes arc used. After leaving the furnace the stuff goes through a pulveriser, and is brought to a fine powder. It then goes into a number of pits to be concentrated. At the last pit the water is acted upon by a syphon in a pecnliarly-constructed box, and lifted from the tank into a receiver at the bottom. The water is lifted in a pulveriser and goes through again, so that any gold or silver held in suspense is precipitated. The i crushed ore is then lifted from the pit and placed in a specially-constructed amalgamator, where a pressure of steam is used, together with some cheap chemicals. It is brought to a certain heat, and kept there till amalgamation is complete. The peculiarity of the system seems to be the injection of steam into the furnace, which the inventor contends has the effect of preventing the volatilisation of the metal. A large quantity of the bullion in our ores exists in a non-metallic form, and it is believed that the steam has the effect of changing that into the metallic form, and so enabling it to be dealt with in the subsequent stages. Professor Brown, who has made several experiments in connection with the system, is convinced that it is of value, and thinks it well worth a trial on a laige scale. Mr. C. C. McMillan and other gentlemen have combined to enable a fair experiment to be made at Onehunga, where five tons of quartz from Karangahake will be tested. Mr. Lockwood believes that the smelters at Frieburg must know some process by which the gold and silver in the stone in a non-metallic form can be reduced to a metallic form, or else they would not be able to give the prices they do for quartz. He puts the price of treatment by his process at £1 to £1 ss. -