THE KARANGAHAKE -FURNACE. DESCRIPTION OF THE PARKES PROCESS.

Te Aroha News, Volume VI, Issue 318, 21 November 1888, Page 3

THE KARANGAHAKE -FURNACE. DESCRIPTION OF THE PARKES PROCESS.

As the new furnace at Karangahake is now in thorough working order, and has been running splendidly for over a week, per' haps a shorb account of the works may be of some interest to your readeis. Ifc is just three years since Mr R. K. Davis erected the first furnace here, which was one ot the La'Montcs, and which, with its attendant refinery, blower, crusher, water- raco, tiamways, etc., cost over £8,000, and was then used ior only iour days, when it was shut down and pronounced a failure, not because it could not smelt the ores, but because the treatment was ,too expensive, and so it has remained ever bince, rusting and rotting away, a sorry monument of misplaced confidence and misapplied capital. Now at last it has been taken down and put on our side and its succe3slul rival has taken its place, Whether the old furnace ever had a fair trial or nob is a subject on which there is great diversity of opinion"; but bo that as if may the new oiie'has certainly proved itself a great success, and is now going day and night, giving out lava-like streams of metal and slag, and at night illuminating the whole fawnsh'ipi' To MrlT.'JM.< 'Chambers belongs the credit of this new venture, and I am sure that everyone is glad to see his pluck and enterprise rewarded

CONSTRUCTION OF T#E FURNACE. The new furnace is a reverberatdry one, on the lines patented by Mr Alexander Parkes, and has been built under the immediate supervision of that veteran metallurgist himself, who, with Mrs Parkes, has been residing at Karangafiake for that purpose for uhe past three months, and vvhosince thefuinaces;arted(al though over 75 yearns of age) is to be found at his post at all hours ot the day and night. The old hirnace. a.^ mot-t oL your readeib areaware.was acupoia or blast furnace, übing hard coke for fuel, and icquiring a strong blast, which was biipphed by one of jJaker'fe rotary blowers, whyroas the new one, as I have alt eady &aid, i& a leveibeiatory furnace, using coal ior fuel, and not roquning any blast. (A very gooi idea of the shape, etc., may be got by referring to Chamber&'s Encyclopedia wheie he tieatfc of lead smelting-. ) Another difference is, that Mr Parkes has the quartz ground much liner than was the case befoie, and on that account requnes much le&s in the way of fluxes. There is also a great dilieience in the number of men lequired in the working of the furnace," so that with the saving o± '-labour and the saving of Euxet*. the cost of toeating will be very much less now than formerly.

..PURCHASE OF THE ORE. Of course thi& furnace resembles the other in that ib does not tieab small parcels ot oro for the public, and indeed this would be an impossibility, as the ores require blending and mixing with- the tiuxeb, etc., to say nothing of the damage the furnace would sustain, if it had to be cooled and cle ned out after every small lot of ore. But all ores brought tor treatment arc bought by the furnace propiietois at so much per cent, on their ast-ay value, the. percentage ranging from 30 tor the very low grade ores to 75 and 80 iui the higher grades ; and this sum is paid to the- producer clear of all charges, % so that "he ha& no risk or further expenses. It then rest? with the furnace proprietors to get what they can rib the lowest possible cost, the usk of bavins or losing resting entirely with., them. When a parcel of ore is received at the works, whefchti it ib one ton or fifty, it is put thiough the stone crusher and rollers and giound line enough to pass through a sieve or scieen having 64 holes to the square inch. Ib is then thoroughly mixed, and three sample^ are taken from it, one to be assayed by the buyer, one by tne s-ellor or his agent, and the thud is sealed up and deported with Sjoma disinterested person as a check. Then, il the assays made by the buyer and seller ngiee, well and good, but if not, the check sample is sent to an indepem ent a&-.ayer, and between the three the price is arranged. In the great majoiity of caf-e&. however, the check is. not required, a» die system adopted for sampling is ho perfect that the d&sayn rarely vaiy more than a few .-hillings per ton. Ot course, even then the seller i» nob obliged to accept the price oiteied, but can remo\e his ore if he wishes, the only charga being a tow shillings for grinding. , In some cases a ton or so is sent fiibt to see how it will yield, and, proving saUsfac_tory, the balance ha 5*5 * been sent atcerwards. In our case over ninety tons have been already purchased trom our mine.

CRUSHING THE QUARTZ. Ail die ores, flakes, etc., on arrival at the w.iks, are received on a large platform, which holds about 50 ton 6. This platform, or paddock, as it is called, is at the back of the building, and is eight feet above the upper or sampling floor, and from it the orth are fed into the crusher, then pass through the rollers and are delivered on the iloorjeady for sampling and mixing. The quavbzwhen fedinto thecrusher varies in size from walnuts to .pieces as largo as a man's head, but when it falls on the floor eight feet below it is all reduced, to a powder, and ' this, with the v very hardest flinty quartz ,Cftn be done at the rate <rf two tons per hour. In the sampling floor r is a trap door o -nnected with the furnace below by an iron hopper or shoot,' vvhich just holds enough for a charge Thfs hopper has a sliding door in the bottom which is controlled, by the furnace men below, who, when they wish to put in a charge, draw the door and it drops down : the men on the floor above them immediately filling up the hopper again. The timcrequired to smelt each charge is about four hours. THE SITE OP THE WORKS. In fcelecting Karangahake as the place to erect the furnace Mr Chambers secured at once a building in which to pub it where there was a refinery ready tor use, a good floor for sampling and storage, a splendid water power tor crushing and grinding, and the whole connected with the leading mines in the district by good ground ami arial tramways, and by the county road, But even with these advantages the expenses of erecting the plant have been very heavy. Ot course, the old furnace had to be removed, then the building had bo be enlarged, and a new tramway had to be constructed to geb the materials over the river. Hoppei's and paddocks for the ores, etc. , had to be made, -and a new set of rollers had to bo got and erected, and altogother there has been a-gi*eat deal of work done, and a lob of money spent. Mr Par.kes himself has been on the ground all the time . the work has been going on, superintending, and is at present devobing his whole bime and attention to smelting aiid refining. The management r of the works generally has been inbrusbed to Mr J. M. Hasletb, who seems to have carried them out in a very careful and substantial manner, and who is

skill in charge of the grinding and sampling , pare of the work. Mr Chambers has also -sponfc # .a, gpe,afc,. v doai of < tinge lie,re deserves very "great credit for^having "brought the undertaking toy*ueh,a'J3uccessful issue. A ffIOPEiFUL OUTLOOK. The people of Karangahake have ,had many, disappointments, and have labouredi under many disadvantages, "but still they have had faith in tHeir «f,ee£s ; they knew that the bullion was" there?" if* they could only geb it out and save it — but this they were unable to do by the old battery^ process, in ma,ny cases getting- less than 20 per cent, of' the assay value, and out of this having to payhe,avy charges for carting and crushing.' Their hopes were raised when LaMoiite appeared on the scene, and again a year' later when Railey's pans were tried, but in both cases only'to* be dashed- down again lower than ever. Let us hope .that this third venture, wibhin many, years will have a long. run, of success, and thatthe difficulty of. treating the refractory ores of Karanga,hake will be a thing- of the, past, and that those who have so long had patience and have held on through all difficulties will at length reap tHeir reward. — (Correspondent. )