industry, led to an increase in the output of lead concentrates from that region, the total in 1912 being 595 tons. The production of lead in Kentucky was 106 tons. The upper Mississippi Valley_region, embracing adjoining portions of Wisconsin, Illinois, and Iowa, was the scene of some of the earliest lead mining in the United States. The mines were at first worked exclusively for lead, but since 1860 the production of zinc ore has predominated over that of lead ore, with which the zinc ore is associated in many mines. The lead content of lead concentrates produced in the district in 1912 was 3,330 short tons, as compared with 4,038 tons in 1911. The southeast Missouri disseminated lead region has in recent years made the greatest gains in production of all the lead-producing districts of the United States, and since 1908 has annually exceeded the production of the Coeur d'Alene region, which formerly held first rank. The ore of the southeast Missouri region is almost wholly lead ore, although, particularly in the southern portion of the area, there is in many places considerable copper, nickel, and cobalt mixed with the lead. These occur in sufficient quantity to constitute the chief value of the ore in the North American mine at Fredericktown. An increasing quantity of zinc blende is also being found in the ore, ranging in the lead concentrates from a trace up to 5 per cent. Several of the milling plants remove the zinc as a table middling in concentration, and others similarly treat the coppernickel-cobalt sulphides. The latter are salable, but no zinc recovered from the disseminated lead ore has been marketed. Silver also occurs in the ore to the extent of a little over 1 ounce to the ton of lead concentrates. The ore occurs in disseminated bodies of large size at depths ranging from 100 to 550 feet, though at a fairly definite geologic horizon. The crude ore in 1912 yielded 5.3 per cent of lead concentrates, which carried an average of 67.1 per cent of lead. The lead content of the lead ore mined in the southeast Missouri region in 1912, including also a small quantity from shallow lead mines in adjoining counties, was 146,913 short tons, as compared with 147,754 tons in 1911 and with 131,499 tons in 1910. The production in 1912 was practically the output of six companies in St. Francois and Madison counties. Of three other companies in Madison County, two-the North American and the Hudson Valley or Phoenix-were in financial difficulties and made no production; the third-the Madison Lead & Land Co.-leased the Catherine mine and mill to the Federal Lead Co. The St. Louis Smelting & Refining Co. relinquished its lease of the Potosi Lead Co.'s mine near Leadwood and the mine was operated by the owners, the ore being concentrated on custom contract. The property of the Mine La Motte Lead & Smelting Co. was taken over on a 10-year lease by the St. Louis Smelting & Refining Co., as reported, at 10 per cent royalty, with privilege of purchase for $800,000. The Joplin region includes southwest Missouri, southeast Kansas, and northeast Oklahoma. This is the greatest zinc-producing area in the United States and furnished 40 per cent of the total recoverable zinc production of 1912. The lead is practically all recovered as a by-product in concentrating the zinc ores. The lead content of the lead concentrates produced in the Joplin region in 1912 was 35,915 short tons, as compared with 36,474 tons in 1911 and with 34,817 tons in 1910. The lead content of lead concentrates produced in southwest Missouri in 1912 was 30,156 tons, as compared with 31,114 tons in 1911. Kansas likewise fell off slightly in lead output, but Oklahoma gained more than one-third over the production of 1911. North Arkansas made a small quantity of lead concentrates, about half as much as in 1911, in milling zinc ores. WESTERN STATES. New Mexico's lead output nearly doubled in 1912, the figures being 2,747 short tons as against 1,483 tons in 1911. This output was derived from three counties, Grant and Socorro counties yielding nearly equal quantities, with a much smaller output from Luna County. The production of lead in Colorado increased from 34,840 tons in 1911 to 37,621 tons in 1912. Lake County ranked first, and was followed by San Juan, Pitkin, San Miguel, Mineral, Summit, and Clear Creek counties, in the order named. In Montana the production of lead increased from 3,216 tons in 1911 to 3,723 tons in 1912. Nearly all the metal-mining counties in Montana made a small yield of lead, but Cascade, Jefferson, Lincoln. and Silver Bow counties, with a production of 3,128 tons in 1912, against 2,392 tons in 1911, produced 84 per cent of the output for the State. Idaho, with 142,093 tons, as against 136,278 tons, made a gain of 4 per cent in lead production in 1912 over that of 1911, which was the largest for several years. This output of lead was made by the mines of the Coeur d'Alene region and by two mines in Lemhi County. The lead smelter at Hahn was burned in September, and the only smelter operated in the State in 1912 was the old lead stack at Clayton, in Custer County, acquired by the Idaho Smelting & Mining Co. in the latter part of the year. The production of lead in Utah in 1912 was 70,156 tons against 68,248 tons in 1911. Of the 1912 output, 31 per cent was derived from mines in the Bingham district, which produced 21,911 tons. The Park City district produced 21,056 tons in 1912, or 30 per cent of the total lead output, while the Tintic district mines yielded 11,786 tons. The output of lead in Arizona in 1912 was 3,403 tons, as compared with 5,137 tons in 1911, a falling off of over 30 per cent, though it was still considerably above the average for the last few years. The ore came from the Warren district, of Cochise County, and from Mohave County. Nevada produced six times as much lead in 1912 as in 1911, surpassing any production in the last ten years. The exact figures are 9,750 tons, as compared with 1,632 tons in 1911. The increase was due principally to adjustments of litigation and to the completion of the railroad spurs to Bullionville and at Pioche, Lincoln County, in 1912. Regular shipments of lead ore were made through the latter half of the year. Clark County also had a large lead output. The production of lead in California in 1912, which was less than in 1911, was derived from Inyo, Mono, and San Bernardino counties. The exact quantities are 572 tons in 1912, as against 699 tons in 1911. The output of lead in Washington in 1912 was only a little over one-sixth that of the previous year, there being only a few shipments from Stevens County. The total output was 64 tons. The Tacoma smelter was remodeled to treat copper ores. METALLURGY. CONCENTRATION AND SEPARATION. The problems of concentration and separation of lead ores do not differ essentially from those concerning zinc ores or the complex sulphide ores of lead and zinc. The various adaptations of the principles of flotation and of electrostatic separation to such ores have been discussed in the chapters on zinc in Mineral Resources of the United States for 1908 and for 1910-1912, to which the reader is referred. SMELTING. LEAD SMELTERS AND REFINERIES IN 1912. In the following list the attempt has been made to give all the lead smelters and refineries in existence or under construction in the United States in 1912. The plants which produced in 1912 are given in ordinary type; those which were idle are listed in italics. List of lead smelters and refineries in the United States in 1912. ARIZONA: Mowry-Consolidated Mines, Smelter & Transportation Co.1 CALIFORNIA: Keeler-Four Metals Mining & Smelting Co.1 Needles Needles Mining & Smelting Co.' Selby-Selby Smelting & Lead Co. Refinery also. COLORADO : Denver-Globe plant, American Smelting & Refining Co. Durango Durango plant, American Smelting & Refining Co. Georgetown-Western Metals Co. (Malm dry chlorination process.) construction. Leadville Arkansas Valley plant, American Smelting & Refining Co. IDAHO: Clayton-Idaho Smelting & Mining Co. Enaville North Fork Smelting & Mining Co. ILLINOIS : Aurora-Aurora Metal Co.* Chicago-Goldsmith Bros.' Smelting & Refining Co.' Under Chicago-National plant, American Smelting & Refining Co. Refinery only. East Chicago-International Lead Refining Co. Refinery only. Grasselli-United States Metals Refining Co.' Refinery only. Betts electrolytic process. 1 Not operated for several years. 2 Subsidiary of United States Smelting, Refining & Mining Co. Subsidiary of American Smelters Securities Co. Smelters of secondary materials, but treating some lead ores. Subsidiary of International Smelting & Refining Co. 19373°-M B 1912—VOL 1- -23 IOWA: Dubuque J. W. Watters.1 KANSAS: Galena-Galena Smelting & Manufacturing Co. MISSOURI: Desloge-Desloge Consolidated Lead Co. Granby-Granby Mining & Smelting Co. Herculaneum-St. Joseph Lead Co. Joplin-Picher Lead Co. Valle Mines-Valle Mining Co.1 Webb City-Webb City Smelting & Manufacturing Co. MONTANA: Cooke New World Smelter & Mining Co. East Helena-East Helena plant, American Smelting & Refining Co. NEBRASKA : Omaha-Omaha & Grant Smelting Co.' Refinery only. Betts electrolytic process. NEVADA: Nelson-Santa Barbara Searchlight Mining Co.1 Spruce-Black Forest Mines & Smelter Co.1 NEW JERSEY: Newark-Balbach Smelting & Refining Co. Refinery also. Perth Amboy-Perth Amboy plant, American Smelting & Refining Co. Refinery also. NEW MEXICO: Deming-National Mining & Smelting Co.1 PENNSYLVANIA: Carnegie Pennsylvania Smelting Co. TEXAS: El Paso-Kansas City Consolidated Smelting & Refining Co.' UTAH: Midvale-United States Smelting Co. Murray-Murray plant, American Smelting & Refining Co. Tooele International Smelting & Refining Co. WASHINGTON: Keller-Keller & Indiana Consolidated Smelting Co.1 WISCONSIN : Dodgeville-Blue Mounds Mining & Smelting Co.1 NEW SMELTERS AND ADDITIONS TO CAPACITY. The International Smelting & Refining Co. added a lead-smelting department to the copper smelter at Tooele, Utah. Two furnaces of 250 tons capacity each were completed in 1912, and two more were started before the close of the year. Early in 1913 a fifth furnace was begun. The roasting equipment consists of Dwight & Lloyd sintering machines, and there are adequate bag houses. An economical method of treating the leady copper matte from the lead furnaces has been developed at this plant. The hot matte, directly as drawn, is blown up in the copper converters, a portion of the lead being saved as fume in the bag houses, and another portion being caught in the converter slag, which is rich enough in lead to be recharged into the lead blast furnaces. At other refineries, notably at Omaha and Perth Amboy, the leady copper matte from distant plants must first be molten before being blown up in the converters. 1 Not operated for several years. 2 Subsidiary of American Smelting & Refining Co. Subsidiary of United States Smelting, Refining & Mining Co. A subsidiary of the International Smelting & Refining Co., the International Lead Refining Co., completed a refining plant of 200 tons' capacity at East Chicago, Ind. The Parkes process of desilverization is employed. The Balbach Smelting & Refining Co. removed its lead refinery from the former location to a site on Newark Bay and doubled its equipment and capacity. The North American Smelting Co. completed a small lead smelter at Kingston, Ontario, Canada, and started operations at the close of the year. The plant is designed to treat the output of the lead mine belonging to the company near Kingston, and to do custom work for other small mines in that vicinity. The smelter-fume problem continued to invite attack. A description of various plans proposed to overcome the objectionable fumes was given in the lead report for 1910. Where there is a market for sulphuric acid the sulphur gases may be converted into acid. The gases from Dwight & Lloyd machines sintering lead concentrates are being used in Germany for the manufacture of sulphuric acid. By selecting gases from a certain section of the draft intake area a gas much richer in SO, is obtained, and a small amount of gas poor in SO, is rejected. But with a single western smelter discharging daily more than 500 tons of sulphur as SO2, it is clear that all the sulphur gases can not be profitably converted into sulphuric acid. The plans of simple neutralization of fume, although successful and at the present stage necessary, are nevertheless kept up at a dead expense and fall short of the goal of recovering a commercial by-product. One of the later methods to solve the problem is the Thiogen process of Prof. S. W. Young, which proposes to recover sulphur as a by-product. An experimental plan for trying out the process has been installed at the copper smelter of the Penn Mining Co., at Camp Seco, Cal., to handle the gases from the McDougall roasters. The object of the process is to reduce the sulphur gases to sulphur by means of a spray of crude oil. The hot sulphur gases are drawn into a flue heated to low red heat, where they are sprayed with crude oil, pass thence through a number of porous partitions in which the gases are brought into contact with the hydrocarbon and are thus reduced. From the flue the gases and sulphur pass into a condensing chamber, where they are sprayed with water and the sulphur is condensed. The remaining gases are drawn through a short flue to a stack. The Hall sulphur process is another of the methods under development which aim to solve the smelter-fume problem. This process consists in roasting the sulphide ore in such a way that while the metallic bases are oxidized the sulphur is not, escaping with the fume as the sublimate. The sulphides are treated in a mechanical roaster of the McDougall type, in an atmosphere of reducing gases and steam, at a temperature between 600° and 900° C. The sulphur is collected in gas scrubbers, or may be condensed by the Cottrell system of electric precipitation. While applicable only to roasting furnaces in its present stage of development, it is hoped that this process may Carpenter, F. R., Smelter fumes, their condensation and utilization. Proc. Colorado Sci. Soc., vol. 9, 1908, p. 65. |