Chapter XVII: Part X: Smelting Works and Refineries (2)

A shaft furnace will work up a charge of 60 tons, equal to 30 tons of ore, in 24 hours, with a coke consumption of 12 per cent. of the weight of the charge and a blast pressure of 50 mm. of mercury. There are three furnaces, of which two are used alternately for smelting lead ores, while one smaller furnace serves for smelting down products, such as hard lead, copper matte and copper bottoms.

Figs. 43 to 46 show one of the furnaces. It will be seen at once that its construction is similar to that of the standard American furnaces. Pilz furnaces were tried in the first few years, but were finally abandoned, as they could not be kept running for any satisfactory length of time with slags rich in zinc. Diluting the slag, on the other hand, would have led to an increased coke consumption, and would have rendered the slag itself worthless. The furnace, however, differs in several respects from its American prototype; the following are some of the chief characteristics peculiar to it:

The chimney above the feed-floor covers one-third of the furnace shaft, and is turned down in the form of a siphon, to connect with the flue-dust chamber. The lateral faces, which are left open, serve as charging apertures; the central one of these, provided with a counterbalanced sheet-iron door, is used for charging from cars. The square openings at the ends, which are covered with cast-iron plates, are used for barring down the furnace shaft and may also be used for charging. By this arrangement, together with the two hoppers placed laterally on the chimney, it is possible to distribute the charge in any desired manner over the whole cross-section of the furnace. This arrangement greatly facilitates the removal of any accretions in the furnace shaft, as the centrally placed chimney catches all the smoke, while the charge-holes render the furnace accessible on all sides. In case of large accretions being formed, the whole furnace can be emptied, cleaned and restarted in 24 to 36 hours.

The smelting cone is enclosed by cast-steel plates 50 cm. high, instead of having a water-jacket. These are cooled as desired by turning a jet of water on them. The plates are connected to the furnace shaft by a bosh wall 25 cm. thick, which is surrounded with a boiler-plate jacket. These jacket plates also are cooled from the outside by sprays of water. With this arrangement the consumption of water is less than with water-jackets, as a part of the water is vaporized, and the danger of leakage of the jackets is avoided. The cast-steel plates are made in two patterns; there are two similar side-plates, each with four slits for the tuyeres, and two end-plates, provided with a circular breast of 30 cm. aperture, for tapping the slag. The breast is cooled by water flowing down, and is closed in front by a plate of sheet iron, in which is the tap-hole for running off the slag. When cleaning out, this sheet-iron plate is removed and the breast is opened, thus providing easy access to the hearth. The four cast-steel plates are anchored together with bolts at their outer ribs, and rest on two long, gutter-shaped pieces of sheet iron, which carry off all the water which flows down, and keep it away from the brickwork of the hearth.

The hearth, cased with boiler plate and rails, has at the side a cast-iron pipe of 10 cm. diameter for drawing off the lead to the outside kettle; this pipe has a slight downward inclination, to prevent the slag flowing out; every 20 minutes lead is tapped, and the end of the pipe is then plugged up with clay.

The furnace shaft is supported upon a hollow mantel, which serves at the same time as blast-pipe. The blast-pipe has eight lateral tees, which are connected by canvas hose with the eight tuyeres. The mouth of the tuyeres has the form of a horizontal slit, whereby the air is distributed more evenly over the entire zone of fusion.

The precipitation of flue dust is effected in a brick condensing chamber, placed near the beginning of the main flue. The main flue terminates on the hill (see Fig. 43) in a chimney, the top of which is 160 m. above the ground level of the works, affording excellent draft. The condensing chamber (Figs. 49 to 51) consists of a vaulted room, 3.40 m. wide and 6.60 m. long, which is divided into twelve compartments by one longitudinal and five baffle walls. The gases change direction seven times, and pass over the longitudinal wall six times, being struck six times by fine sprays of water. The six atomizers for this purpose consume 1.5 liter of water per minute, of which four-fifths is vaporized, while one-fifth flows off to the lower water basin. By this means 10 to 15 per cent. of the total flue dust is precipitated in the condensing chamber itself, and is removed from time to time as mud through the lower openings, which are water-sealed. The remainder of the volatilized water precipitates the flue dust almost completely on the way to the stack, so that only a short column of steam is visible at the mouth of the stack. The flue to the stack passes for the most part underground through abandoned adits and galleries, thus providing a variety of changes in cross-section and in direction, and assisting materially the action of the condensing chamber.

As the charge of the shaft furnaces is poor in sulphur, no real matte is produced, but only work lead and lead ashes (Bleischaum), which contains 90 per cent. of lead, 1.6 per cent. sulphur, 0.4 per cent. zinc, 0.85 per cent. Cu, 0.99 per cent. Fe, and 0.22 per cent. Sb. By liquation and a reducing smelt in a reverberatory furnace, most of the lead is obtained, along with a lead-copper matte, which is smelted for copper matte and antimonial lead in the blast furnace.

The copper matte, containing 18 per cent. Cu, 25 per cent. Fe, 30 per cent. Pb and 18.4 per cent. S, is roasted dead in a reverberatory furnace, is sintered, and melted to copper-bottoms in a small shaft furnace. These copper-bottoms, which contain 60 per cent. copper and 25 per cent. lead, are subjected to liquation, and finally refined to blister copper.

The zinc-desilvering plant, Fig. 47, consists of a reverberatory softening furnace, two desilvering kettles of 14 tons capacity, a pan for liquating the zinc crust, and a small kettle for receiving the lead from the liquation process.

This pan has the advantage over the ordinary liquating kettle, that the lead which drips off is immediately removed, before it can dissolve the alloy; the silver content of the liquated lead is scarcely 0.05 per cent., while the dry alloy contains 5 to 8 per cent.

The removal of the zinc is effected in a second reverberatory furnace. Formerly the steam-method was used, but the rapid wear of the kettles, and the excessive formation of oxides called for a change in the process. The zinc-silver alloy is distilled in a crucible of 200 kg. capacity, and is cupeled in an English cupel furnace. The details of the reverberatory furnace are shown in Fig. 48.

The composition of the final products is shown by the following analyses; Lead: Zn, 0.0021 per cent.; Fe, 0.0047 per cent.; Cu, 0.0005 per cent.; Sb, 0.0030 per cent.; Bi, 0.0007 per cent.; Ag, 0.0010 per cent.; Pb, 99.998 per cent.; Silver, Ag, 99.720 per cent.; Cu, 0.121 per cent.; Fe, 0.005 per cent.; Pb, 0.018 per cent.; Au, 0.003 per cent.

INDEX

Alloy, retorting the, in lead refining, 267

Alumina, experience with, 259

American Smelting and Refining Co., 4, 6, 26, 93, 113, 252, 295
at Murray, Utah, 287

Atmosphere, effect of on concrete, 242

Bag-house, cost of attending, 246
standard, 246

Bag-houses for saving fume, 244

Bartlett, Eyre O., 244

Bayston, W. B., 199

Bennett, James C., 66

Betts, Anson G., 270, 274

Between products, working up of, 39

Biernbaum, A., 41, 148, 160

Blast furnace of circular form, 253
Spanish lead, 307

Blast, volume and pressure of in lead smelting, 76

Blower, rotary, deficiency of, 251

Blowers for lead and copper smelting, 256
now more powerful for lead smelting use, 252

Blowers, rotary, method of testing volumetric efficiency of, 254
_vs._ blowing engines, 254
_vs._ blowing engines for lead smelting, 251

Blowing engines, when to use, 259

Bonne Terre lead deposits, 18
orebody, Missouri, 13, 14

Borchers, W., 114, 116, 127

Bormettes method, combination processes in, 222

Bradford, Mr., 55

Bretherton, S. E., 251, 258

Broken Hill Proprietary Block, 14, 59

Broken Hill practice, 51
Proprietary Co., 52, 113, 124, 145, 175, 178, 206

Bricking plant for flue dust and fine ores, 66-70

Briquetting costs, 62
methods of avoiding, 63, 64
process, operations, in 59

Bullion, analyses of in lead refining, 281
refined lead and slimes, analyses of, 282

Canadian Smelting Works, 275

Carlton Iron Co., 63

Carmichael, A. D. 56, 199

Carmichael-Bradford process, 175-185
brief estimate of, 209
claims of in patent, 199
recommendations of, 124
process, points concerning, 131

Cement walls, how to build, 241

Channing, J. Parke, 254

Charge-car in smelting, true function of, 94
feeding of in lead smelting, 77
mechanical character of in lead smelting, 78

Charges, effect of large in lead smelting, 77

Cherokee Lanyon Smelter Co., 104

Chimney bases, 237

Chisholm, Boyd & White Co., 64

Clark, Donald, 114, 144, 175

Cœur d’Alene mines, 5, 6, 7

Concrete flues and stacks, advantages and disadvantages of, 242
in metallurgical construction, 234

Connersville Blower Co., 252

Consolidated Kansas City Smelting and Refining Co., 285

Coke, percentage necessary to use in smelting, 259

Croll, H. V., 253

Cupellation in lead refining, 269

De Lamar Copper Refining Co., 297

Desilverization in lead refining, 265

Desloge practice contrasted with others, 46

Doeltz, F. O., 139

Dross, analyses of in lead refining, 279

Dupuis & Sons, 63

Dust chamber, arched form, 231
beehive form of, 232
design, 229
rectangular form, 230
concrete, 235-237

Dwight, Arthur S., 73, 81
spreader and curtain in furnaces, 91

East Helena and Pueblo smelting systems compared, 93
plant of the American Smelting and Refining Co., 302
system of smelting, 88-94

Edwards, Henry W., 234, 240, 242

Einstein silver mine, 14

Engine, blowing, proper field of, 257
blowing, and rotary blowers, 258

Eriksson, Hjalmar, 306

Federal Lead Co., 38
Mining and Smelting Co., 7

Feeders, cup and cone, for round furnaces, 81

Ferraris, Erminio, 311

Flat River mines, 18

Flue gases and moisture, effect of on concrete, 242

Flues, concrete, 234, 240, 242

Foundations for dynamos, 236

Fremantle Smelting Works, 145

Fume-smelting, cost of, 33
in the hearth, 32

Furnace operations at Desloge, Mo., 45

Furnaces at Desloge, Mo., 43
reverberatory, at Desloge, Mo., 42

Galena, experiments in roasting, 129
lime-roasting of, 14
new methods of desulphurizing, 116
roasting of by Savelsberg process, 122, 123

Gas, furnace, effect of on cement, 240

Gelatine, use of in electrolytic lead refining, 275

Germot, A., 224
process, 224

Globe plant of the American Smelting and Refining Co., 304
Smelting and Refining Co., 244

Greenway, T. J., 59

Guillemain, C., 133

Harvard, Francis T., 242

Hearth, covered-in, 36

Heat, effect of on cement, 242

Heberlein, Ferdinand, 113, 167, 199

Hixon, Hiram W., 256, 258

Harwood, E. J., 51

Hourwich, Dr. Isaac A., 27

Huntington-Heberlein process, 113, 144-147
consideration and estimate of, 203-209
credit due to, 126
process as distinguished from others, 118
economic results of, 155-159

Huntington-Heberlein explained by the inventors, 167-173
process at Friedrichshütte, 148
process, from the hygienic standpoint, 160
ideas of in patent specifications, 117
process, introduction of at Tarnowitz, Prussia, 41
and Savelsberg processes, essential difference between, 192
process, some disadvantages of, 165, 166

Huppertz, L., 121

Hutchings, W. Maynard, 108, 126, 170

Huntington, Thomas, 113, 167, 199

Iles, Malvern W., 96, 252

Ingalls, W. R., 3, 16, 27, 42, 177, 186, 193, 215, 224, 244, 287

Iron, behavior of in silver-lead smelting, 75

Jackson Revel mine, 14

Johnson, E. M., 104
R. D. O., 18

Jones, Richard, 244
Samuel T., 244

Laur, F., 224

Lead, analyses of refined, 281
bullion, electrolytic refining of base, 270
bullion, Parkes process of desilverizing and refining, 263
bullion, softening of, 263
concentrate Joplin district, valuation of, 25
and copper smelting, the Bormettes method of, 215-223
deposits, southeastern Missouri, 18
Joplin district, 8
marketing, 3
-ore roasting, consideration of new processes, 135-138

Lead ore, average prices for, 27
ore, cost of smelting, 32
-ore roasting, theoretical aspects of, 133
ores, Galena, Kan., 24
ores, method of valuing, 26
ores, southwestern Missouri, 24
Park City, Utah, 8
-poisoning in old and new processes, 162-165
refining, electrolytic, 274
soft, Missouri, 25
smelting at Desloge, Mo., 42
smelting at Monteponi, Sardinia, 311
smelting and refining, cost of, 96
smelting in the Scotch hearth, 31
smelting in Spain, 306
smelting at Tarnowitz, Prussia, 41
source of in Missouri, 13
in southeastern Missouri, 7, 10, 17
sulphide and calcium sulphate, metallurgical behavior of, 139-143
total production United States, 5
yield from Scotch hearths, 39

Leadville, Colo., mines, 8

Lewis, G. T., 244

Lime-roasting of galena, 126

Lotti, Alfredo, 215

Messiter, Edwin H., 229, 240

Middleton, K. W. M., 31

Mine La Motte, 14

Minerals, briquetting of, 63

Mining methods in Missouri, 19-23

Missouri Smelting Co., 197

Mould, H. S., Co., 64

Murray smelter, Utah, 291

National plant of the American Smelting and Refining Co., 299

New Jersey Zinc Co., 246

Nutting, Mr., 256

Ore and Fuel Co., 63
different behavior of coarse and fine in lead smelting, 79
treatment in detail by the Huntington-Heberlein process, 150-155

Parkes process, cost of refining by, 99

Percy, Dr., 244

Perth Amboy plant of the American Smelting and Refining Co., 296

Petraeus, C. V., 24

Pfort curtain for furnaces, 82

Picher Lead Co., 197

Piddington, F. L., 263

Potter, Prof. W. B., 15

Pueblo lead smelter, 294

Smelting and Refining Co., 84

Pufahl, O., 38, 291, 294, 296, 299, 302, 304

Pyritic smelting without fuel practically impossible, 256

Raht, August, 251, 254

Refining, monthly cost of per ton of bullion treated, 100

Roasters, hand, and mechanical furnaces, average monthly cost of, 98

Roberts-Austen, W. C., 139

Salts, effect of crystallization of contained on concrete, 243

Santa Fe Gold and Copper Mining Co., 255

Savelsberg, Adolf, 122

Savelsberg process, 186-192
process, claims of in patent, 201
process contrasted with Huntington-Heberlein, 209
process, difference between and Huntington-Heberlein, 197

Savelsberg process the simplest, 132

Scotch-hearth method, permanency of, 195

Scotch hearths, 34

Schneider, A. F., 81

Seattle Smelting and Refining Works, 273

Silver-lead blast furnaces, mechanical feeding of, 81
blast furnace, proper conditions, 73
smelting, details of practice, 73
smelting, modern, 73

Slag-smelting costs, 34

Slime analysis at Broken Hill, 51

Slimes, analyses of in lead refining, 281
desulphurization of by heap roasting, 51
treatment of at Broken Hill, 53-55

Smelter, new, at El Paso, Texas, 285

Smelters’ pay, 32

Smelting, average cost of per ton, 98

Smelting Co. of Australia, 263
costs, 48
detailed costs of, 101, 102
of galena ore, 38
preparation of fine material for, 59

Solution, washing from slime, 277

Sticht, Mr., 256

St. Joseph Lead Co., 16

St. Louis Smelting and Refining Co., 81

Sulphide Corporation, 145

Sulphur dioxide, effect of on cement, 240

Sulphuric acid, making of at Broken Hill, 174

Tasmanian Smelting Co., 145

Tennessee Copper Co., 255

Terhune, R. H., furnace gratings, 84

Thacher, Arthur, 14

Ulke, Titus, 270

United Smelting and Refining Co., 88
States Zinc Co., 295

Vezin, H. A., 252

Walls, retaining, 237

Walter, E. W., 260

Waring, W. Geo., 24

Welch, Max J., 229

Wetherill, Samuel, 244

Wheeler, H. A., 10

Zinc, amount required in lead refining, 265, 266
crusts, treatment of in lead refining, 267
oxide in slags, 108
retort residues, analysis of materials smelted and
bullion produced, 106
retort residues, smelting, 104

FOOTNOTES:

[1] During 1905, antimonial lead commanded a premium of about 1c. per lb. above desilverized, owing to the high price for antimony.

[2] The figures for 1903 and 1904 have been added in the revision of this article for this book. The production of lead in the United States in 1903 was 276,694 tons; in 1904, it was 302,204 tons.

[3] Ounces of silver to the ton of lead.

[4] These figures are doubtful; they are probably too high. (See table on p. 5).

[5] The production of zinc ore in this district has now been commenced.

[6] The manuscript of this article was dated Oct. 5, 1905.

[7] Translated from _Zeit. f. Berg.-Hütten-und Salinenwesen_, LIII (1905, p. 450).

[8] This paper is published in pp. 148-166 of this book.

[9] Abstract from _Transactions_ of the Australasian Institute of Mining Engineers, Vol. IX, Part 1.

[10] In the course of subsequent discussion Mr. Horwood stated that the losses in roasting were 12½ per cent. in lead and probably about 5 per cent. in silver. As compared to roasting in Ropp furnaces the loss in lead was 5 to 6 per cent. greater, but the difference of loss in silver was, he thought, not appreciable. Mr. Hibbard said that the Central mine had obtained satisfactory results with masonry kilns.—EDITOR.

[11] Abstract of portion of a paper presented at the Mexican meeting of the American Institute of Mining Engineers, under the title “The Mechanical Feeding of Silver-Lead Blast Furnaces.” _Transactions_, Vol. XXXII, pp. 353-395.

[12] Abstract of a paper (“The Mechanical Feeding of Silver-Lead Blast Furnaces”) presented at the Mexican meeting of the American Institute of Mining Engineers and published in the _Transactions_, Vol. XXXII. For the first portion of this paper see the preceding article.

[13] Abstract of a paper in _Western Chemist and Metallurgist_, I, VII, Aug., 1905.

[14] Much better work is being done at present, smelting the Western zinc ores, and the residue contains about one-third of the above figure, or 7.5 per cent. of zinc oxide. The high per cent. of ZnO left in residue was mainly due to poor roasting.

[15] There was also considerable coke used of an inferior grade, made from Kansas coal.

[16] Part of the ZnO in roasted matte came from being roasted in the same furnace the zinc ore had been roasted in.

[17] There was less residue on the charges during this month, which accounts for the larger tonnage with a lower blast.

[18] Translation of a paper read before the Naturwissenschaftlicher Verein at Aachen, and published in _Metallurgie_, 1905, II, i, 1-6.

[19] 35 to 40 cm. = 13.78 to 15.75 in. = 8 to 9.12 oz. per sq. in.

[20] _Engineering and Mining Journal_, 1904, LXXVIII, p. 630; article by Donald Clark; reprinted in this work, p. 144.

[21] Owner of the patents.—EDITOR.

[22] Abstract of a paper in _Metallurgie_, II, 18, Sept. 22, 1905, p. 433.

[23] This method is described further on in this book.

[24] Translated from _Metallurgie_, Vol. II, No. 19.

[25] British patent, No. 17,580, Jan. 30, 1902, “Improved process for desulphurizing sulphide ores.”

[26] W. C. Roberts-Austen, “An Introduction to the Study of Metallurgy,” London, 1902.

[27] A. Lodin, _Comptes rendus_, 1895, CXX, 1164-1167; _Berg. u. Hüttenm. Ztg._, 1903, p. 63.

[28] _Comptes rendus_, loc. cit.

[29] Translated from the _Zeitschrift für das Berg.-Hütten-und Salinenwesen im. preuss. Staate_, 1905, LIII, ii, pp. 219-230.

[30] Translated from the _Zeitschrift für das Berg.-Hütten-und Salinenwesen im. preuss. Staate_, 1905, LIII, ii, pp. 219-230.

[31] The manufacture of sulphuric acid from these gases has now been undertaken in Silesia on a working scale.—EDITOR.

[32] A paper presented before the American Institute of Mining Engineers, July, 1906.

[33] _Engineering and Mining Journal_, Sept. 2, 1905.

[34] This term is inexact, because the hearths employed in the United States are not strictly “Scotch hearths,” but they are commonly known as such, wherefore my use of the term.

[35] Percentages of lead in Missouri practice are based on the wet assay; among the silver-lead smelters of the West the fire assay is still generally employed.

[36] This improvement did not originate at either Alton or Collinsville. It had previously been in use at the works of the Missouri Smelting Company at Cheltenham, St. Louis, but the idea originated from the practice of the Picher Lead Company, of Joplin, Mo.

[37] This refers especially to the Savelsberg process.

[38] A. D. Carmichael, U. S. patent No. 705,904, July 29, 1902.

[39] _Metallurgie_, 1905, II, i, 1-6; _Engineering and Mining Journal_, Sept. 2, 1905.

[40] _Metallurgie_, 1905, II, 19; _Engineering and Mining Journal_, Jan. 27, 1906.

[41] _Metallurgie_, 1905, Sept. 22, 1905; _Engineering and Mining Journal_, March 10, 1906.

[42] _Engineering and Mining Journal_, Oct. 21, 1905.

[43] Translated by W. R. Ingalls.

[44] As originally published the title of this article was “Lead-Smelting without Fuel.” In this connection reference may well be made to Hannay’s experiments and theories, _Transactions_ Institution of Mining and Metallurgy, II, 188, and Huntington’s discussion, _ibid._, p. 217.

[45] Excerpt from a paper, “Concrete in Mining and Metallurgical Engineering,” _Transactions_ American Institute of Mining Engineers, XXXV (1905), p. 60.

[46] A Discussion of the Paper by Henry W. Edwards, on “Concrete in Mining and Metallurgical Engineering,” _Transactions_ of the American Institute of Mining Engineers, XXXV.

[47] _Engineering News_, Nov 30, 1899, and U. S. Patent No. 665,250, Jan. 1 1901.

[48] A discussion of the paper of Henry W. Edwards, on “Concrete in Mining and Metallurgical Engineering,” _Transactions_ of the American Institute of Mining Engineers, XXXV.

[49] Abstract from the _Journal_ of the Chemical, Metallurgical and Mining Society of South Africa, May, 1903.

[50] Abstract of a paper in _Transactions_ American Institute of Mining Engineers, XXXIV (1904), p. 175.

[51] Silver not given. This was the case, also, with the gold in the bullion. The slimes contained 0.131 per cent. of gold, or 39.1 oz. per ton.

[52] A constituent company of the American Smelting and Refining Company.

[53] Translated from _Zeit. f. Berg.-Hütten.-und Salinenwesen im preuss. Staate_, 1905, LIII, p. 433.

[54] Abstract from a paper in _Zeit. f. Berg.-Hütten-und Salinenwesen im preuss. Staate_, 1905, LIII, p. 439.

[55] Translated from _Zeit. f. Berg.-Hütten.-und Salinenwesen im preuss. Staate_, 1905, LIII, 490.

[56] Abstract from a paper in _Zeit. f. Berg.-Hütten-und Salinenwesen im preuss. Staate_, 1905, p. 400.

[57] Abstract from a paper in _Zeit. f. Berg.-Hütten.-und Salinenwesen im preuss. Staate_, 1905, p. 400.

[58] Abstract from an article in _Zeit. f. Berg.-Hütten.-und Salinenwesen im preuss. Staate_, 1905, LIII, p. 444.

[59] Translated from _Oest. Zeit. f. Berg.-und Hüttenwesen_, 1905, p. 455.