US532809A - Thomas davies nicholls - Google Patents

Description

:Nrrn STATES PATENT m res,

THOMAS DAVIES NICHOLLS, O-F SKEWEN, NEAR, NEATH, AND CHRISTOPHER JAMES, OF SWANSEA, ENGLAND.

METHOD, OF RE F'INJNG. COPPER.

SPECIFICATION forming part-f: Letters: Patent No. 532,809, dated January 22,1895.

Application filed June 18,1891- Serial No. 396,715. (No-specimens.) Patented in England November 21, 1890 No. 18,898 1 in Spain July- 9, 1891, ITO-121214;; inItaly July 14, 1891, XXV, 29.950, LVIII, 450,- in Newfoundland August 10.18.91 in France September 30, 18-91, No- 2'1'45025, and in UapeofG'ood HopeFebruaryZd, 13-92, No 74L To all whom, it may concern.-

Be it known that we, THoMAs DAVIES NICH- OLLS, residing at Gl'an-Mor Villas,Skewen,. near Neath, and CHRISTOPHER JAMES, of Ida Villa, Swansea, in the county of Glamorgan,

England, have invented an Improved Method of Refining Copper, of which the following is a specification.

The invention has been patented in Great to Britain, No. 18,898, dated November 21', 1890; in France, No. 214,025, dated September 30, 1891; in Italy, XXV, 29,950, LVIIL450, dated July 14, 1891; in Spain, No. 12,214, dated July 9, 1891; in Newfoundland August 10, 1891, 15 and in the Colony of the Cape of Good. Hope,

No. 741, dated February 27, 1892;

This invention. relates to an improved;

method of producing refined copper from copper matte, regulus or precipitate and the operations entailed therein are conducted as follows; In the ordinary methods now in use copper matte or regulus, consisting principally of copper and sulphur, is piled, in as: large pieces as practicable, in a roaster fur- 2 5 mace, and slowly sweated down while exposed to a current ofair let in through-the-side door of the fnrnace,-through air holes or plugs, orthrough passages arranged through the fire by the workman; thus burning off the o sulphur nearly, and leaving the copper, after' melting and skimming to be tapped out as pimple or blister copper. This operation takes seldom less, than twenty fourhours for the production of three tons of pimple 5 or blister copper from matte-of seventyfive or seventy-six per cent. while a large amount of copper passes into the roaster slags, which have to be resmelted. The blister or pimple copper, thus made, is then filled 0 as pigs into a refinery furnace and again sweated down under an oxidizing flame,

skimmed, refined and brought to the required pitch, and finally laded into cakes, ingots, au-

odes, &c.

In the new method proposed herein, we avoid the expensive and wasteful two operations of roasting and melting, first in a roaster and again in a refinery furnace by substituting. a cal'cinati'on of'alportion only of the matte, then mixing this calcined portion with a suitable portion of raw (uncalcined) matte. Thisimixtu-re isthen charged d-i'rectl'yinto a refinery furnace, and melted atonc'e into impure metallic copper or blister icopper containing about. ninety-seven and one-half percent. of copper with sulphu rand traces of other metallic impurities which is brittle and unmalleable. It is then refined in the usual way in the hearthof' the same refinery furnace in which the calcined and raw 6o matte (of say seventy-six tose-ven ty-eigh't per cent. of copper) has been sine'l'ted. This usual way of refiningis. by oxidation of the liquid. metal in the hearth: while it is being. 'fiap'ped orstirred by snita-ble'hand hoes or flaps until all the sulphurandanytraces-of' 1 iron, nickel,.arsenic, and antimony have been i oxidized and removed"v as slag, volatile bodies being vol'atilized and any excess of oxidation lis then removed by po-ling with timber 7o 2 poles. The metal is thus reduced to refined icopper of 99.6- or one hundred per cent. of jicopper by the" continuous process in the'one furnace and is malleable and of great tenacity, lit for the market, and. is, then formed as required into cakes, ingots, anodes, &c.

We: find in practicethat the best, and most @econom-ical matte forour process is one of iaboutseventy-six to seventy-eight per cent. @of'copper, matte of this pitch containing but llittle iron, and so making very little slag in itherefinery furnace; The whole of this matte is crushed through athree-eigh-ths inch screen (or smaller it convenient though when rich matte is treated fine dust is wasteful).

A portion of our matte or regulus we calcine in reverberatory calciners or revolving cylinder calciners or any calciner at present in or- .dinary use. The calcination of this portion of matte is so conducted until itis dead and mixed with such a portion of raw matte as will suffice (when melted together) to render all the copper in both portions as metallic copper of a pitch similar to the blister copper from the ordinary roaster. Both 5 portions, so mixed, form the refinery charge.

The reactions which insure the success of this method of working may be described as follows: Copper matte of the preferred pitch consists essentially of copper sulphide (011 8). This when calcined perfectly would be changed to copper oxide (0110) of equal weight with the copper sulphide operated on. This copper oxide (G110) upon being melted with its own weight of raw copper matte (Ou S) produces metallic Cu from both portions with the evolution of nearly all the sulphur and oxygen as sulphur gas, as expressed by the well known formula:

In practice we find that to perfectly calcine the portion of matte so treated is tedious and expensive, the calcination of the copper sulphide to red oxide of copper (Ou O) being comparatively easy while the further calcination of this red oxide to black oxide (CuO) requires so much longer time and greater heat, that although the black oxide will carry its own weight of raw matte in the refinery charge, it is cheaper to only so far calcine our matte that upon trial it is found that about two parts of calcined matte and one part of raw matte will, upon melting render all the copper as blister copper with very little slag.

We claim, that by treating only about two thirds of our matte in a calciner, and then melting the total quantity in a refineryfurnace with the immediate production of metallic copper, which is at once refined in the hearth of the same furnace in which the mixed calcined and raw matte has been smelted without remelting, good copper is produced at far less direct cost than by the ordinary roasting and refining processes; that more copper is obtained in a salable form and far less slags produced than by the roasting, melting and skimming, first in a roaster, and again in a refinery furnace with the production of heavy slags in each operation.

In our method of working, we find that all volatile impurities (arsenic, antimony, bismuth, &c.) are more freely got rid of than in the roasting process, partly in the thorough calcination of the calcined portion, and again during the evolution of the large volume of sulphur gas, given off on melting the mixed charge in the refinery, aided by the intense chemical heat developed by there action set up by the combining of the melting oxide and suphide.

The non volatile impurities (iron, nickel, &c.) are got rid of, to at least as great an extent as by the roasting process, by a judicious mixing of the proportions of calcined and raw products, so as to obtain a slag of melted oxide, in more or less quantity upon the liquid bath of metallic copper in the hearth of the furnace. Such non volatile impurities are naturally collected in this slag, and are skimmed off with it, a suitable flux (such as sand, lime, niter, 850.) being added to the refinery charge when very impure matte is operated on. Although matte of seventysix to seventy-eight per cent. of copper is preferred, correspondingly good results are obtained from poorer mattes.

The actual cost of practically working this method has been found to be less than half the cost of the ordinary method, as carried out in well conducted works using the old method.

Although we use by preference matte of seventy-six to seventy-eight per cent. of copper and a calcined portion of the same or other matte, our invention applies with correspondingly good results to all matte of from forty-five to eighty per cent of copper.

Having fully described our invention, what we claim, and desire to secure by Letters Patent, is-

The herein described method of producing refined copper from copper matte, consisting in crushing the matte, calcining a proportion of the crushed matte, mixing therewith a suitable portion of uncalcined matte, charging said mixture directly into a refinery furnace and melting the same and finally refining the product in the same furnace on the hearth thereof whereby the material is thus reduced to refined copper by a continuous process in the same furnace, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

THOMAS DAVIES NICHOLLS. CHRISTOPHER JAMES. Witnesses:

EDWIN GEORGE PROMEROF, DAVID RICHARD BOWLER.