[129] Adapted from compilations by Adolph Knopf, of the U. S. Geological Survey.
The four districts now of pre-eminent importance are, in order, Broken Hill in New South Wales, Australia; southeastern Spain; southeastern Missouri and Coeur d’Alene, in Idaho: which are credited respectively with about 19, 16, 12 and 10 per cent. of the world’s production in 1913.
United States.
—The chief producing regions and their percentage of the domestic lead production in 1915 are as follows:
| Region | Percentage of total domestic production |
|---|---|
| Southeastern Missouri | 33 |
| Coeur d’Alene, Idaho | 27 |
| Utah | 18 |
| Joplin (in Mo., Kans., Ark., and Okla.) | 6 |
| Colorado | 5 |
As regards the types of ores and the character of the lead produced, there are two metallographic provinces: the Mississippi Valley, including southeastern Missouri and Joplin, and the minor district of Wisconsin, producing as soft lead 39 to 45 per cent. of the total domestic production; and the Western province, in which the ores are complex, carrying precious metals and often antimony and copper. All of the output from the Western province, but only a part of the soft lead, is desilverized.
Ninety per cent. of the ore mined in southeastern Missouri comes from St. Francois and Madison counties. The ore deposits contain predominantly galena, and are disseminated in Cambrian limestone over large areas at depths of 100 to 550 feet. Copper, nickel, and cobalt occur in the Madison County ores, and copper concentrates are separated and shipped by nearly all the companies in the region. The principal operating companies, with the names of companies absorbed by them or now subsidiaries, shown in parenthesis, are: St. Joseph Lead Co. (Doe Run Lead Co.), Federal Lead Co., National Lead Co. (St. Louis Smelting & Refining Co.), Desloge Consolidated Lead Co., Baker Lead Co. (St. Francois Lead Co.), Boston Elvins Lead Co., Missouri Metals Co. (Mine La Motte Co.), and Missouri Cobalt Co. (North American Lead Co.). The St. Joseph Lead Co. is normally the second largest lead-producing company in the United States. Its holdings have a conservatively estimated life of 20 years, at a rate of production of 2,000,000 tons of ore, or 80,000 short tons of lead, per annum. In 1917 this company mined 2,485,431 tons of ore, nearly half the total output of the region. The Federal Lead Co., a subsidiary of the American Smelting & Refining Co., is the next largest producing company in the region. In 1915 it mined and milled 1,355,000 tons of ore. The National Lead Co., through its subsidiary, the St. Louis Smelting & Refining Co., works three mines near Flat River and has a concentration plant with a daily capacity of 2,400 tons. Its smelter at Collinsville treats its own concentrates, as well as those of the Baker Lead Co. and the Boston Elvins Lead Co. The Desloge Consolidated Lead Co. operates three mines and a mill of 1,700 tons’ daily capacity; its ores are smelted by the Federal Lead Co. The Missouri Metals Co. operates the Mine La Motte and a mill treating 700,000 tons annually at the 1917 rate. In 1915 it was estimated that this mine could produce 3,000,000 tons of ore annually for sixty years.
In the Joplin region, which is chiefly in Missouri but also includes adjacent areas in Kansas, Arkansas, and Oklahoma, the ores lie at three horizons in horizontal limestone and chert beds of Lower Carboniferous age. At the upper horizon, usually 100 to 150 feet below the surface, the ore occurs in clayey chert breccias. The ore bodies are characteristically “runs” up to 300 feet wide, and continuous in one horizon for several hundred feet and, rarely, for more than a mile. The middle horizon, or “sheet ground,” at a depth of 150 to 300 feet usually ranges from 6 to 15 feet in thickness. The ore, mixed galena and blende, cements brecciated chert. The third and lowest horizon, in sandy limestones, contains disseminated ores mainly, and as yet is little exploited. In 1915, about 4,000,000 tons of ore was mined from the upper horizon, and 6,500,000 tons from the middle horizon or “sheet ground.” The average lead content of the ore as mined was about 0.25 per cent. Most of the lead concentrates are sold in open market. The Webb City district is the most important in the Joplin region, and the American Zinc, Lead & Smelting Co. is the largest galena producer. Most of the output is by lessees and small operators. The Joplin district ranks second in importance. The A. W. C. Mining Co. is the largest miner of “sheet ground.” The Ravenswood and Ritz mines of the United States Smelting, Refining & Mining Co., in Jasper County, produce 218,000 tons of ore annually. The concentrates of this region are chiefly smelted by the plants of the Eagle-Picher Lead Co. at Galena, Kansas; Joplin, Missouri; Webb City, Missouri; and by the Granby Mining & Smelting Co. at Granby, Missouri.
The Coeur d’Alene region is in Shoshone County, Idaho. The deposits are metasomatic veins formed by replacement of siliceous sedimentary rocks along zones of fissuring, and carry mainly galena and siderite with some pyrite and sphalerite. In 1915 the crude ore shipments amounted to 95,169 tons with a lead content of 35,271 short tons. The remainder of the ore, or nearly 96 per cent. of the total, is concentrated to carry about 50 per cent. lead. The 1915 yield of concentrates of all kinds amounted to 329,530 tons, having a lead content of 128,928 short tons, making the total lead content of crude and concentrate shipments 164,199 short tons. The mining companies form three groups, determined chiefly by their relations or affiliations with the smelters, as follows: The Bunker Hill group, comprising the Bunker Hill & Sullivan Mining & Concentrating Co., and the Hecla Mining Co.; the Day group, comprising the Tamarack & Custer Mining Co., the Amazon-Manhattan mine, and the Hercules Mining Co.; and the American Smelting & Refining group, comprising the Federal Mining & Smelting Co. and various small producers.
The mines of the Bunker Hill & Sullivan Mining & Concentrating Co. had reserves on December 31, 1917, of 3,457,634 tons. The ore bodies are replacements of quartzite. This company’s production in 1917 was 493,030 tons of ore, the metallic lead recovered by smelting being 46,996 tons. The Bunker Hill & Sullivan Co., while still shipping its own ores to the Helena plant of the American Smelting & Refining Co., built its own smelter at Kellogg, Idaho, where it smelts the Hecla and other ores. The Day family controls the Hercules, and Tamarack & Custer companies, the Northport smelter at Northport, Washington (now closed down), and the Pennsylvania Smelting & Refining Co. at Pittsburgh, Pa. The 1916 shipments of the Hercules had a lead content of about 22,000 tons. Both companies are close corporations and make public little information as to their operations. The Tamarack & Custer probably has large reserves of ore averaging about 9 per cent. lead; it has produced as much as 3,000 tons of shipping ore and concentrates per month. The Federal Mining & Smelting Co. operates several mines. One-sixth of the stock is owned by the American Smelters Securities Co. and all its silver-lead ores and concentrates are contracted to the American Smelting & Refining Co. The Success Mining Co., working two mines, has been an important producer. The Interstate-Callahan has been chiefly a zinc producer but ships some lead concentrates to the Salida plant of the Ohio & Colorado Smelting Co.