there, it may be assumed that his experiments have been attended with success, or at any rate that the progress in treatment justifies the expectation of success. IMPORTANCE OF THE INDUSTRY. production of The value of such works to our province, if established and carried on at paying figures, must appear obvious when it is seen how large the The copper industry is elsewhere as limited to production of ingot copper alone. The the world. following table, published in the report on the Mineral Resources of the United States for 1887, gives the copper production of the world in long tons for the eight years 1880-7: copper in Michigan. This is an increase of 69,537 tons in seven years, but as prices were maintained at a high rate during the greater part of the time by the operations of the French copper syndicate the increase may be regarded as abnormal. The total product of the United States in 1879, according to the census, was 56,115,354 lb. ingot copper, of which 45,830,262 lb. was credited to the mines of northern Michigan. The capital employed in the industry in Michigan as Production of reported in the census was $30,413,551, of which $24,116,366 was the value of northern real estate, $5,275,185 the value of plant and $1,022,000 the amount of working capital. The total number of employés in the census year was 5,004, made up of 2,076 miners, 2,742 laborers and 186 officers of the administrative force, and the amount of wages paid in the year was $2,661,243. The value of materials or supplies used was $1,215,206, and the value of the product was $7,979,232.* In 1887 the total product of the United States was 180,920,524 lb. and that of northern Michigan 75,471,890 lb., the average selling price of which was about 11 cents per pound. The copper production of Great Britain has fallen from 15,968 long tons in 1860 to not more Production in than 1,500 tons in 1887. In Chili also the output appears to be falling off in other countries recent years, the exports from that country having been 25,498 tons in 1857, 44,654 tons in 1867, 45,400 tons in 1877 and 29,150 tons in 1887. In Spain and Portugal however production is on the increase, the total for 1881 having been 32,697 tons in 1879 and 52,219 in 1887. At the famous Rio Tinto mine in Spain the ore occurs in large masses very similar to that of the Sudbury ranges, saving that it contains no nickel; it is a low grade of pyrites. One of the veins is 8,000 feet long by 180 wide and another threefifths of a mile long by 600 feet wide, and it is computed that there are *United States Census of 1880, vol. xv, pp. 798-800. copper Famous Spanish, mines of copper. 150,000,000 tons of ore in sight. It is worked by an English company which has a paid-up capital of £3,250,000 stg., and the total cost of the mine as shown by the annual report for the year ending December, 1888, was £3,331,095. The report for that year shows that the profits on sales of produce realised £1,142,777, and after providing for payment of interest, expenses of administration, bonds redeemed, plant, repairs, etc., there remained available for dividend a net profit of £754,706. The quality of the ore will appear by the following table, giving the quantity raised from the mine for shipment and local treatment in the seven years 1882-8, together with the average copper contents of the ore: Ancient mines which pay It will be shown farther on that the copper contents of the Sudbury mines are twice as great as those of the Rio Tinto, besides their contents of nickel. large dividends. The Rio Tinto and Tharsis mines in Spain are of great antiquity. Sir Hussey Vivian says there is good reason to believe that they were worked by the Romans,* and in the opinion of some people the Tharsis mine is the Tarshish of Solomon's day. Yet those mines, ancient as they are and long-worked though they have been, are still yielding immense profits to their owners, as the following payments of dividend show: NOTE.-A balance of £202,206 was carried forward in revenue account after paying the large dividend of the Rio Tinto company in 1888. *"Last year (1879) I visited the famous Rio Tinto and Tharsis mines and found them covered with mountains of old slags, just as the often prophesied New Zealander may some day wander over and wonder at our Swansea slag-heaps. There is good reason to believe that these workings were Roman, and no one looking at those heaps can doubt the great scale upon which they worked and the skill with which their operations both below and above ground were conducted. They rejected and left unworked the low-produce pyrites, but they followed eagerly the rich veins of yellow ore which traverse those mighty deposits. I saw the wonderful northern face of the great Open Cast at Rio Tinto, compact pyrites some 80 or 100 feet deep and 1,000 feet long, pierced at frequent intervals by ancient Roman galleries, following with true mining instinct the veins of rich ore. I examined critically the slag. heaps, and was astonished at the freedom of the slags, made perhaps nearly 2,000 years ago, from prills. At this moment, with all my accumulated experience of copper smelting, I don't These statistics will enable us to form some conception of the value to Ontario of the great copper ranges lying in the Huronian region beyond Georgian bay, as yet but very imperfectly explored, and of the possibilities which await their development. production of Caledonia Fifteen years ago the world's production of nickel was about 600 tons, and in consequence of its comparative rarity and of new uses to which it The world's was found to be adapted the price had in a few years risen in England from nickel. 4s. to 11s. per lb.* In 1876 the average price in the United States was $2.60 per pound and the total product 201,367 lb. ; in 1882 the product was 281,616 lb. and the price $1.10 per pound; but in 1887 the product fell to 205,566 lb. and the price to 65 cents. This was a result of the discovery and working of high-grade nickel ores in the island of New Caledonia, a penal colony of France, about the year 1876, and which in the years 1882-4 The New produced from 800 to 1,000 tons of metallic nickel, while no new uses were found for it in the arts. Consequently, although the mines of New Caledonia have been worked under unfavorable conditions, the supply exceeded the demand, and prices steadily dropped. + Hitherto nickel has been used for making the alloy known as nickel-silver, which possesses great strength and whiteness, and is produced for the supply of manufacturers of spoons, forks, plated-ware and other articles. It is also largely used in the United States, Alloys of nickel Germany, Belgium and other countries in the minting of small coins, for which it is well adapted. But recent experiments carried on in Great Britain know how they made those heavy irony slags so clean. I had but little time to examine the ground, and I failed to find the remains of their furnaces. I failed also to find metallic bottoms, the famous 'Eisensamen' or 'iron pigs,' which almost invariably accumulate in the bottom of blast-furnaces working on ores of this nature, and which do now occur largely in the most scientifically conducted works of Germany and Sweden. Surely these 'old men' knew their business !"-Vivian's Lecture on Copper Smelting, p. 7. *Phillips' Elements of Metallurgy, p. 362. +The following account of the New Caledonia nickel mines is given in the report on the Mineral Resources of the United States for 1885: "The veins, so far as strike and dip are concerned, are fairly regular, striking north-northeast and south-southwest and dipping almost vertically. But the contents vary widely and suddenly in grade. The veins are not very persistent, and it is asserted, after experience which must be considered final, that they do not descend deeper than 300 to 500 feet, even that depth being very rare. The ore is mined by the usual methods and is sorted by hand at the mine and sacked. M. de Peloux describes in detail how frequently the ore is handled, evidently disapproving of it; he enumerates that the ore of the Thio district, which is best equipped with means of transportation, is handled twelve times. This is partly due to the fact that the sacks are taken to the river bank, the bar at the mouth of which they can only cross at floodtide, and that the beach is so shallow that the ore must again be lightered to the sea-going vessels in the offing, which carry it to the smelting works at Noumea. Thus the irregularity of the ore distribution and the high cost of transportation greatly increase the expense of mining. To this must be added the scarcity of suitable labor in New Caledonia. Among the force available are, first, those transported criminals who are liberated with residences restricted to the colony. They are lazy and difficult to handle. They receive from 6 to 9 francs for eight hours' work. Then there are the natives of the New Hebrides islands, engaged under supervision of the government for a period of three to five years. Although apparently cheap labor, they cost 3 francs a day, are unfit to work in the mines, and are unable to adapt themselves to the climate, from 25 to 30 per cent. always being in the hospital, where the majority die. Their immigration has been finally prohibited by the French government. The Australians are fair miners and good workmen, but they demand at least 12.50 francs a day. Latterly Chinese laborers have been brought in and give better promise, although they require constant watching. Added to the high cost of labor as compared with European standards, there is often trouble through want of water. The ore is taken in lots of 200 to 250 tons to Noumea, where it is worked in two blast furnaces, one of which is used for nickel ores alone and the other for mixed ores of nickel and cobalt. The charcoal and coke come from Australia, and, in spite of the proximity of the two colonies, are very dear. Charcoal costing 12.50 francs at Sydney is worth 40 francs at Noumea, while coke sells at 70 to 80 francs. The object in smelting the ore is to produce a matte carrying from 60 to 70 per cent of metal It is granulated and shipped to England."-p. 300. mines, and their effect on prices. The Welsh and systems. with alloys of nickel and steel seem to justify the hope that a new and valuable use has been found for the metal, and if the claims now made are well founded it is not unlikely that the resources of all known mines may soon be taxed to supply the demand for it. PROCESSES OF SMELTING ORES. There are various processes for the smelting and refining of copper ores, all of which are well described in Phillips' Elements of Metallurgy, Dr. Percy's Metallurgy and other works, but in the short account here given the writer follows very closely the two greatest living authorities as scientific and practical metallurgists,-Sir Henry Hussey Vivian who favors the Welsh, and Dr. Edward D. Peters who favors the German system.* "When I use the term South Welsh system of copper smelting," Vivian says, "I carefully avoid the term 'principle' of copper smelting, because the same principle must be the base of all copper smelting. The ends are the same, but the means of attaining them are different. The difference lies in our use of reverOrigin of the Welsh practice. beratory furnaces both for calcining and melting, while the other systems of the world depend (or perhaps more correctly depended) on roasting in heaps and melting in b'ast furnaces." Before the Welsh system was introduced three centuries ago the practice had been to roast and melt the ore and regulus repeatedly; as many as sixteen and twenty-two times are mentioned, one-half roastings and one-half meltings, and the time occupied was as many weeks as fires. But with the new system, the inventor of which was one Jochim Gans, the work could be completed in five days. † This practice was adopted with the commencement of copper smelting in South Wales in 1584, and in the following year they were able to smelt 24 cwt. of ore every day with one furnace and to treat any kind of ore, which in 1586 was further increased to three tons per day with a mixture of charcoal and mineral coal, which proves the use of a reverberatory furnace. ‡ * See Copper Smelting, its History and Processes, by Henry Hussey Vivian, M.P., a lecture delivered at Swansea, in the theatre of the Royal Institution of South Wales, December 20th, 1880; and Modern American Methods of Copper Smelting, by Edward D. Peters, junr., M. E., M.D., 1887. 66 + The ore was prepared for the furnace by crushing and roasting it, after the vitriol and burnt cinder were carried off by water, which, Vivian says, distinctly proves reverberatory calcining. Nedham (quoted by Vivian) says: 'By Mr. Jochims order of working we canby once rosteing and once smelting the ure (w'ch shall be done in the space of three days) the same copper ure shall yield us black copper and copper stone which nether Mr. Daniell nor his Sonne could or yet can do under xvi times passing through the fire and xvi times doeing thereof, and further in once rosteing and once smeltinge the same black copper and copper stone again, which shall be done in two days after Mr. Jochims order of worke inge, I will bringe the black copper and copper stone into perfect rough copper, which Mr. Stemberger cannot make under xxii tymes passing through the fire and xxii weekes in doinge thereof and sometymes more. ་ "On the 7th of March, 1586, Ulrick Frosse wrote to Mr. Carnsewe (superintending a mine in Cornwall): Wee looke dayley for the copper refiner from Keswicke, and have in readines as much copper roste and blake copper as will make a 20 tonne of good copper.' He reported in the same letter that he could melt in 7 hours 24 c. of owre, with 8 or 9 seks of chare coles and 3 horslod of sea coles; melting many sorts of owres to gether is the most proffet and will smelt a greattayll souner.' Now this passage shows that they had so increased their melting as to do upward of three tons per 24 hours, and that they could take any kind of ore, but, above all, it proves that they were using reverberatory furnaces, because 'sea coles' are suitable for such furnaces and not for blast furnaces. The charcoal was probably mixed with the coal to prevent its binding too strongly, just as we now use 'free' coal. The charge of 24 cwt. was curiously enough the same which was used by works up to a recent date. My object in giving these extracts is to show, not alone how copper smelting commenced in South Wales, which is of great local interest, but also how the South Welsh process of copper smelting, which may be said to be at this moment the ruling process of the world, began. '-Vivian on Copper Smelting, p. 13. There is a great variety of ores and combinations of copper, the purest being the native copper found in the lake Superior mines at Houghton; but the copper of commerce generally occurs in combination with sulphur, and, following Vivian, attention may be exclusively directed here to the smelting Varieties of ores. of sulphide of copper in combination with sulphide of iron, earthy matters and "every known and unknown metal and mineral in creation." sulphide ores. Roasting or By smelting is meant fusion of the ore and whatever fluxes may be necessary, when the copper owing to higher specific gravity separates from the slag and is recovered by appropriate means. The first object in the pro- Treatment of cess must be to lose as little of the copper as possible in the slag and to make the fusion easy. In the case of oxidised ores it is obtained at once in a metallic condition, somewhat adulterated with sulphur, iron and other foreign substances, and requires only a single operation or at most two to bring it into merchantable form. But when it occurs with sulphur or arsenic, with an excess of foreign sulphides, the result of fusion is merely concentrated ore, freed from the earthy gangue. It is the first business of the copper smelter to consider the varying nature of his ores. In those containing large quantities of sulphide of iron he takes care to roast or calcine highly in order to obtain oxide of iron to flux the ores and produce a regulus or matte sufficiently rich in copper-his standard being from 30 to 35 per cent. Whether the process is carried on in a reverberatory furnace, a muffle, or in heaps, the object to be obtained is the same in all cases. Of the merits of the different systems Vivian says: "The most ancient, namely, roasting or burning in heaps, is the least costly, provided the copper ore is sufficiently rich in sul- calcining. phur or bituminous matter, as in the case of the Mansfield Kupferschiefer; but it is not applicable to ores poor in sulphur and in any case it is very tedious, occupying weeks or even months, and therefore necessitating enormous stocks of ore in comparison with the quantity treated. The South Welsh calciner on the other hand is rapid in its action, never exceeding 36 hours and for ordinary ores 12 hours, while the quantity treated is considerable and the cost of fuel and wages consequently small. Our large calciners Reverberatory at Hafod treat 14 tons each charge, the time of course depending on the nature of the ore we are operating on." These calciners are reverberatory furnaces 28 feet long by 13 feet wide, inside, with a small fire-grate at one end, and the ore is spread evenly over the bed of the furnace. They are simple and under complete control, Vivian says; any ore can be treated in them, whether containing much or little sulphur, and the process can be arrested at or pushed to any point. Where it is intended to utilise the sul- Manufacture of phur for the production of sulphuric acid three kinds of calciners are used, sulphuric acid. viz., kilns in which the material is burnt in pieces the size of road metal; the Gerstenhoffer calciner, in which it is burnt as powder, and the muffle calciner, which is worked by transmitted heat. calciners. tory and blast In weighing the advantages and disadvantages of the reverberatory and blast furnace systems of smelting the calcined ore, Sir H. Vivian says the blast The reverberafurnace is slightly more economical in the cost of fuel, and in all cases it furnace systems produces a cleaner slag; but he contends that its working is much more complicated, and through its tendency to reduce the oxide of iron in the ore compared. |