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tant smelting countries, are not important as zinc ore producing regions. Japan is another country that is more important in the smelting business than as an ore producer.

Data collected by the Bureau of Mines show that the order of production of the various zinc ore producing countries in 1913 was as follows:

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The productions of the more important zinc-mining countries in 1917 were in the following approximate order: United St tes, Germany, Australia, Mexico, Canada, Italy, Japan, Spain, Siberia, and India. Probably the order at the present writing is not greatly different, but it should be noted that the boundaries of Germany are not yet (July, 1921) defined, and the greater part of the zinc resources (as well as reduction works) of that country have been or may be transferred to the new State of Poland.

DOMESTIC PRODUCTION. The United States has increased its proportion of the world's output from only about 20 per cent in the early nineties to about 60 per cent during the war period. Since the world output also has largely increased in this time, this percentage increase involved a much greater absolute expansion than would appear from the above figures. The output of domestic zinc mines in 1917 was eight times the annual output of 25 years ago. Most of the growth took place since 1914, during which time the domestic production increased over 50 per cent.

Methods of production. Very nearly all of the zinc ore mined in the United States must be concentrated before shipment to the smeltery. There is some production, especially of carbonate ore, that needs only to be roughly sorted by hand to bring it up to a grade that will be accepted by smelters, but by far the greater part of the domestic zinc ore must go through a more or less complicated dressing operation.

There are no particular features that distinguish the mining of zinc ores from the mining of other metals, such as copper and lead. As a rule the ores are not unusually hard and are easily extracted by standard methods of underground mining. Extensive operations on a large scale as exemplified in the working of the large copper properties are not in vogue. Deposits of zinc ore comparable to the "porphyry” deposits of copper in the Southwest are unknown. The nearest approach to this condition are the zinc areas near Joplin,

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but that district is characterized by the great number of small operators. A similar condition exists to a considerable degree in other sections of the United States. Zinc mining as well as smelting has been peculiarly free from large combinations of capital and, with the exception of perhaps a half dozen exceptionally large producers, most of the zinc mines are operated independently.

The amount and character of treatment necessary for the preparation of a salable product from zinc ores as they come from the mine will vary widely according to the deposit and the locality. For certain ores, notably those containing zinc as the only recoverable value or those in the Mississippi Valley region where the zinc and lead are easily separated, comparatively simple ore dressing is sufficient. Little machinery and equipment is required, and the amount of capital necessary for the successful conduct of a small mine and mill is so small as to permit the development of individual ownership or operation by little companies. On the other hond, the successful utilization of many of the complex ore deposits which are characteristic of the Rocky Mountain region calls for the highest metallurgical skill, complicated equipment, and a considerable outlay for plant, in addition to the cost of developing the ore body to the point of production.

Ag eat many mines are equipped with mills, but these mills rarely do much if any custom work. "Joint ownership of mines and smelting works is rare, as ownership of mines has never been the important feature of the zinc industry.?

History.---The oxide ores of New Jersey, Pennsylvania, and Wisconsin were the early source of ore supply for smelting operations until after the Civil War. As early as 1774 a shipment of red zincite was made from Franklin Furnace to England under the impression that it was copper ore. This same district also furnished the first spelter produced in the United States. Only one small lot was turned out and was used for making the brass for the Government standard set of weights and measures in 1838. It is also reported that during the War of 1812 some brass was made from these same ores, probably by the cementation process.

No zinc was produced in Missouri until 1867, when small works were erected at Potosi, but lead had been mined since 1848 in Jasper County, near Joplin, and the presence of zinc must have been early recognized. The first zinc ore from the Joplin district was marketed in 1872, and in the following year the production became important. The ore was shipped at first to Illinois for smelting. Joplin rapidly increased in importance and became the leading producing district in the United States.

As the lead mines of Wisconsin, Virginia, Colorado, and other States were developed the zine resources of this country were better recognized. For many years zinc was considered a detrimental ingredient of ores and, in the early history of many camps, an excess of zinc was the cause for closing down properties that might otherwise have been profitably worked. Vearly all the large zinc-producing districts were originally opened up for the production of other metals.

! This subject will be discussed more fully in another section of this report.

Even the German control of the European zinc situation before the war was obtained almost wholly through ownership and regulation of the production of reduction works and through long-term contracts for the ore output of independent mines (notably in Australia).

An important factor in the zinc-mining situation has been the development of separation processes for the recovery of zinc from other sulphides and gangue. One of the earliest successful devices was the standard Joplin jig, which proved highly advantageous for the treatment of the coarser sizes of the comparatively simple combination of galena and sphalerite, present in that region. Next came the Wilfley concentrating table that allowed a similar separation on all material down to the slime sizes. The latter machine even permitted a partial elimination of pyrites, a mineral of only slightly greater specific gravity than blende. Slime tables followed, but were not so successful in the preparation of clean products.

As the treatment of complex ore developed a great demand arose for a process that would make a valuable zinc product out of the “zinc-iron” middling. Various methods have proved more or less satisfactory, notably roast-magnetic and electrostatic separation. Preferential flotation is now an important probability and has been successfully applied in many cases.

Domestic resources and localities of production.--Zinc deposits are found in almost every State in the Union, and in 1917 production was reported from 23 States. In spite of this wide distribution, however, over 80 per cent of the total output of the United States is furnished by six districts. These are (1) Missouri-Kansas-Oklahoma (Joplin or "Komspelter'), (2) New Jersey (Franklin Furnace), (3) Montana (Butte), (4) Wisconsin, (5) Colorado (Leadville, Red Cliff, and Breckenridge), (6) Idaho.

The first named is the largest zinc-producing region in the world, and has contributed approximately one-seventh of the annual output of the world in recent years. This region, which goes by several names, lies mostly in southwestern Missouri, more or less adjacent to Joplin, but also overlaps contiguous territory in Kansas, Oklahoma, and Arkansas. The ore is typically zinc-lead, and contains no precious metals.

The activity in this district reflects the state of the zinc market. The production comes from a large number of small individual operators, many of them marginal producers or “leasers” who can operate their mines only when the ore can be sold fairly readily at a price more or less above the occasional minimum prices that result from market fluctuations. If the low prices continue for more than one or two weeks, these weaker producers have to quit and go to work elsewhere, perhaps on farms or in the city. A large proportion of the ore smelters are situated in that vicinity, attracted not only by the nearness to the ore supply, but also because of the availability of cheap fuel, both coal and gas. Its importance is therefore even greater than the figures of its actual production, which were equal in 1917 to more than one-third of the total for the country.

New Jersey, the second largest producer, is remarkable for the unusual character of the ore in its one important district, Franklin Furnace. The deposits there are the only ones of the kind in the world. The peculiar purity of the ore and its abundance and grade have been the foundation of the success of the largest single zincproducing corporation in the world, the New Jersey Zinc Co. New

1 86.6 per cent in 1917.

Jersey furnished 16.9 per cent of the domestic output of zinc in ore in 1917, and its proportion of the total output of grade A or high-grade ore suitable for the manufacture of the purest grades of spelter is much greater. It is the most important factor in the pigment trade as the best grades of American process zinc oxide are made from these ores.

Colorado was the third largest producer for many years, but has been surpassed by Montana. In 1915 both of these States were furnishing approximately 13 per cent of the domestic output; but in the active development of the next two years, Colorado failed to increase its tonnage rapidly enough to keep pace with other parts of the country, and dropped to fifth position, supplying only 8.3 per cent of the domestic total in spite of the fact that its actual tonnage output increased slightly. Montana produced 13.1 per cent of the total United States mine production of zinc in 1917. Wisconsin, which in 1915 was in fifth place among the zinc-producing districts, furnishing 7 per cent of the domestic total, increased its proportion to 8.4 per cent, or slightly more than that of Colorado. Idaho is the sixth State in order of production, supplying 5.6 per cent of the total output of the country in 1917.

The ores of all these districts are different from either of the first two types. Wisconsin ores are the most nearly similar to those of Missouri, but invariably contain much greater amounts of iron sulphide, together with arsenic and antimony. The difficulty of separating these from the blende delayed the economic development of these areas for a long time. The ores of the Rocky Mountain States

a are invariably complex in the number of metals present, but here their resemblance to one another ceases. The Montana ore can be Fasily concentrated to a product containing 50 per cent and more of zinc. In addition to zinc some copper, a little lead, and important silver values are present in the concentrate.

In Idaho, the ores resemble those of Montana in that a high-grade concentrate can be made; but the silver is usually lower and the lead somewhat higher.

It is in Colorado that the typically difficult-to-concentrate complex ore is found. These ores, disregarding the carbonates which are of secondary origin as distinguished from the primary sulphides, have a variety of structure and of minerals that rarely occur in any of the other important districts. The percentage of iron is invariably high and this undesirable element is present not only as pyrite-difficult to separate-but as a constituent of the black jack which, for the most part, contains only 45 to 50 per cent, and frequently less, zinc. Gold, silver, lead, or copper are generally present, sometimes all together.

The essential differences between these more important districts are roughly outlined in the above summary. A more detailed description, including many of the zinc-producing regions has been prepared but, on account of its length, can not be presented here and will be found in the auxiliary files of this Commission. Many of the districts present no markedly unusual features and zinc mining is quite similar to other mining operations in those districts.

70619--21-0-27--2

Zinc content of recoverable zinc ore-Domestic production, by States.
(From Mineral Resources, United States Geological Survey.)

(In short tons.)

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Arizona.
Arkansas.
California.
Colorado.
Idaho..
Illinois..
Kansas.
Missouri.
Montana..
Nevada.
New Jersey.
New Mexico.
New York.
Oklahoma..
Tennessee.
Utah.
Virginia.
Wisconsin
All other..

24

2,742

2, 281 4,379
994 664 748

1, 401 2, 173
38, 545 47, 304 66, 111
2, 802 4, 170 6,953
3, 549
4,219

4,065
13, 229 10, 272 10,633
128, 589 122, 515 136, 551
15, 819 21, 905 13, 459
1, 354 1,774 6,661
68, 678 77, 445 69, 755
9, 044 5, 119

6,783
6,394

5, 150 5, 769
966 1, 117 2, 191
8,184
8,920

8,534
794 1,032 249
25, 927 29, 720 33,050

102 249 752

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9, 110

9, 839 10, 447
3, 208 6, 815 6, 691
6,547
7,628

5, 436
52, 297

67, 143 60, 158 35, 077 43, 253 39, 927

5, 534 3, 404 4,267 14, 365 12, 448 20, 249 136, 300 155, 960 132, 918 93, 573 114, 630 93, 130 12,188 16, 222

11, 154 116, 618 | 112, 020 120, 846 12, 702

18, 285 15, 100 2, 455 4, 507 5, 192 14,314 28, 754 85, 835 16, 461 26, 428 28, 498 12, 146 14, 786

10, 643 1, 267 2, 276

1, 703 41, 403

56, 803 59, 742 924 2, 116

1, 423

13, 992
10, 425
7,995

174
31, 113

344

105

7 100 12

2 156 22 8.

1. 49,

Total.

327,712 345, 260 378, 816 406, 416 406, 959 586, 489 703, 317 713, 359

1 Estimated.

1912

1916

6 1919

Relation of domestic production to domestic consumption.TI following statistics do not include the ore consumed by produce of zinc oxide or manufacturers of electrolytic zinc, and represen therefore, only the receipts of zinc ore by smelters. Exports of o are also not included. The data for imports do not correspond wit

1 the figures of the Department of Commerce. They are reporte by the smelters, in the case of bonded smelting, when the spelte leaves their works while the Government reports date from the tim the spelter is entered for export at the customhouse. The differ ence in periods covered by the two sets of reports accounts in par for the discrepancies.

Smelter receipts of zinc ore in short tons.'
State. 12 1913 1

1914
1915 5

1917 1918 Arizona.

11, 937 Arkansas.

9, 347 6,357 1,567

14, 718 1,500

17, 243

14,837

1, 737 California

1,962
7,017 12, 854
6,639
Colorado.

20, 225
6,796
8, 827

27, 445 41, 291
212, 423

12, 444
220, 166
Idaho..

5, 231
164, 739
148, 359

194, 418
19, 482

184, 304 31, 835 Kentucky.

82,995 57,001

78, 767
947

104,575
86, 172

62, 109 Missouri-Kansas..

434 1,863 2, 460 289, 177 280,000 Missouri - Kansas

2,019 247,723

799 278, 099 369, 397 301, 809

(*) Oklahoma - Arkansas.

(8) Montana.

(3) (3) (3) 34, 034

(8)

(9) 91, 257 Nevada.

476, 954 125, 663

200, 528 20, 654

233, 645 22,313

171, 904

152, 905 20, 447 New Mexico..

24, 949 25, 889

51,670

35, 045 14, 593 Oklahoma.

19, 733 15, 369

37,042 4, 325

35, 734 23, 500

16,353

26, 247 Tennessee..

13, 206
6, 635

25, 231
42, 799

153, 035
8, 297
Utah...

18,708
38, 527

43, 309
24, 539

38, 488
27,073
Wisconsin.

45, 924
20, 322
21, 535

43, 240
90, 762

21, 381
89,662
Others and undis-

14,758
74, 311
90, 128
91, 561

137, 248 123, 506
tributed..
56,099 57, 241

57, 936

122, 490 Total.

111, 273

192, 393 98, 870 Mexico..

805, 109 884, 021 845, 821 1,116,698 1,395, 469 1,387,657 1,099, 072

29, 436 Canada.

19, 965
16, 414

49, 171
9, 707

142, 687 135, 368

6,012 Australia..

49, 532
10, 532
14,000
31, 877
21, 502

14, 502

68, 443 Other foreign....

134, 464
37, 031

618
9,211

441

452,272

8,013 4,007

63

751

73, 394 Grand total.

31, 714

2,373 844, 252 5 909, 998 872, 767 1,257, 528 1,777, 891 | 1,613, 272 1, 166, 097 W. R. Ingalls, Engineering and Mining Journal. : See Missouri-Kansas-Oklahoma-Arkansas.

See under separate States. + Including Illinois and Iowa. • In addition to the ore reported from Canada and Mexico, smelters received a few thousand tons of me from Europe and Eastern Siberia in 1913.

• Metal produced.

465, 743

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