Papers - Mining - Mining Practices of the St. Joseph Lead Company in Southeast Missouri (Mining Technology, May 1943)

Southeast Missouri is the largest and oldest lead-producing district in the United States. For the year 1941, the statistical picture of pig-lead production, stated in short tons (partly estimated by the Engineering and Mining Journal) is as follows. Tons World production................. 2,000,000 United States Production .........- 460,000 Southeast Missouri production..... 142,000 The consumption of primary lead in the United States in 1941 was approximately 900,000 tons, or almost double the country's production. The largest previous year's in in the United States was 718,000 tons, in 1926. The largest quantities of lead are used for cable sheathing, storage batteries and white lead. During 1941 tetraethyl lead for auto and aviation gasoline consumed 50,000 tons of lead. The entire lead production of Southeast Missouri is now mined by the St. Joseph Lead Co., whose dominant position as the largest producer in the United States of lead directly from ores is best shown by the fact that in 1941 it produced approximately 31 per cent of the lead production of the United States from its mines in southeast Missouri, where 22,000 tons of ore, averaging over 3.00 per cent lead, is mined per working day. It is known that lead was mined at Mine La Motte, Madison County, Missouri, by Renault in 1723. Other white men and Indians probably did some mining prior to that time. Since 1865, the recorded production to Jan. I, 1942, shows that the St. Joseph Lead Co. and the various other companies that have operated in St. Francois County mined lead ore, which, after milling and smelting losses produced 5,980,000 short tons of pig lead. • About 95 per cent of the present lead production of Southeast Missouri is mined in St. Francois County. The northern part of this area is 60 miles south of st. Louis. The remainder of the lead is obtained at Mine La Motte, about 25 miles southeast from the center of the producing area in st.Francois county, Prospecting In this district, most of the ore is discovered by surface and underground diamond drills and by prospect drilling underground with rock drills. Each 2-ft. length of the cuttings from these Jack-hamer prospect holes is assayed for lead. These holes are marked and the records are entered on maps. It has been found that close drilling—100-ft. centers of holes, and sometimes less—is necessary in order to locate most of the smaller commercial ore bodies, many of which previously had been missed by drilling the areas with holes spaced 200-ft. centers or more. To date, geophysical and other methods of prospecting, apart from diamond and Mining Practices of the St. Joseph Lead Company in Southeast Missouri