Mechanization is of primary importance in contributing to increased man-hour output of crude ore. The industry has installed much labor-saving machinery during the past 10 years. Electric-power shovels of increased capacity are used in open-pit operations and improved locomotives are used for hauling. Improved techniques of caving, blasting, and drilling, more effective use of explosives, and the wider use of mechanical loaders and other types of machinery have contrib uted greatly toward increasing the quantity of ore mined per man-hour. Other important factors affecting the productivity per man-hour are: the availability of skilled workers, prices of metals and the existence of Governmentsponsored price supports, efficiency of management and production methods, labor-management cooperation, weather conditions, and the position or location of ore bodies. The percentage of working time used in direct production of ore as compared with time used in mine development and improvement also affects the number of man-hours required to produce a given amount of ore. Although there has been a general increase in productivity per man-hour since 1939 in terms of crude ore mined, there has not always been a corresponding increase in terms of recoverable metal produced. (See tables 5, 6, and 7.) This is because high-grade ores ar being depleted and it is necessary to exploit ores with relatively small percentages of metal content. This tendency is offset somewhat by technological developments in concentrating, smelting, and refining, and also, by the discovery of new, richer ore bodies. Output per man-hour varied from year to year among the individual metals during the period 1939-50 because of the particular circumstances prevailing in each year. From 1939 to 1941 demand for metals increased steadily and production was concentrated in the larger, richer, more efficient mines which had weathered the general industrial decline of the 1930's. As these established mines increased production to near capacity operations output per man-hour increased. Output per man-hour of recoverable lead and zinc, however, decreased in 1940 because demand for lead was slow. The lead-zinc mines concentrated on zinc production which is not the most efficient method of development for this type of mine. The result was a reduction in total output of metal per man-hour of labor. As the demand for lead rose, output per man-hour again increased in 1941. Demand for all metals was heavy in 1942 and 1943. Although the industry developed open-pit mines and used more mechanical equipment in order to increase production, output per man-hour declined in iron and lead-zine mining primarily because of losses of skilled workers to other industries and to military service. Acute labor shortages developed and available workers were largely inexperienced. The premium-price plan for nonferrous metals, adopted by the Government in 1942, made possible the mining of low-yield, high-cost ore and adversely affected output per man-hour. Output per man-hour in iron mining decreased further in 1943 because of an unusually late opening of the Great Lakes shipping season. Unfavorable shipping weather during the season hampered iron ore shipments and prevented pits from producing at full capacity. Output per man-hour in copper mining increased in 1942 and 1943 despite manpower losses, largely as a result of the development of several new open-pit mines and technological improvements in equipment and operations. Also, in 1942, the War Production Board issued an order closing the gold mines, and a few of these experienced mine workers transferred to the copper mines. In general, increases in output per man-hour were reported in 1944 and 1945 in spite of serious losses of experienced workers. This was largely the result of increased open-pit mining, extensive improvement in mechanization and operating techniques, the closing of some of the higher cost mines when the Federal Government began decreasing premium payments, and, in the latter part of 1945, to an improvement in the labor supply. In 1946, strikes both in the mines and in other industries, and other factors such as high operating costs and price uncertainty brought about a drop in mine production and a sharp reduction in productive efficiency. Strikes reduce the average level of output per man-hour because underground mines must be maintained even when they are not being worked. Output per man-hour increased in the years following 1946, as a result of such factors as the restoration of more stable economic conditions, the increasing availability of competent workers, technological improvements in mechanization and metal recovery methods, increased emphasis on open-pit mining, and the closing of high-cost mines due to the discontinuance of the Government's premium-price plan. Although technological advances in metal mining will continue, output of recoverable metal per man-hour probably will decrease slowly in the long run. The most important factor is the gradual deterioration in the quality of the ore mined. Also, in underground mines, when ore is mined at increasing distances from the shafts up which it is hoisted to the surface, more man-hours must be expended in hauling ore and in traveling to and from the working faces. In the long run, the factors making for decreasing output per man-hour probably will tend to overbalance the gains normally attributed to technological advances. The expected decline in productivity will take place slowly, however, and changes in the man-hour output of recoverable metal are not likely to be substantial in the next several years. Manpower requirements To meet production goals for domestic metal mines it is estimated that 120,500 workers will be needed in the industry by 1955, an increase of 19.3 percent over the 1950 employment of 101,000. The largest proportional increase in manpower requirements will be in copper mining, followed by lead-zinc mining. The smallest proportional increase will be in iron mining. Estimates by year are shown in table 8. The estimates of worker requirements for each metal are derived by relating production goals, output per man-hour, and weekly hours of work. In the event that production goals are revised or if there are significant changes in the rate of output of metal per man-hour, these estimates will be adjusted. TABLE 8.—Estimated manpower requirements in metal mining, 1952–55 BY THE DEFENSE MINERALS ADMINISTRATION FOR THE RECORD OF THE HEARINGS HELD BY THE SUBCOMMITTEE ON MINES AND MINING, MAY 10 AND 11, 1951 BRIEF OF DISTRICT PROGRAMS IN MANGANESE CURRENTLY UNDER CONSIDERATION BY SUPPLY DIVISION, DMA May 9, 1951 GENERAL The lack of economic production of domestic manganese ore in peacetime has left the country without a dependable supply should foreign shipments be interfered with for any reason. It is vital to the needs of defense that new sources of manganese be put into production at the earliest date possible. The following program outlines those projects which promise the greatest returns and which have already been approved either formally or in principle. INDIVIDUAL PROGRAMS Butte-Philipsburg, Mont. Small independently owned mines in the Philipsburg and West Butte districts, Montana, are believed to be capable of supplying 20,000 to 30,000 long tons per year of manganese concentrates meeting minimum stockpile specifications for a period of 3 to 5 years. A plant designed to beneficiate these ores exists on the property of the Domestic Manganese & Development Co. at Butte, and the proposed operation can be put into effect without capital expenditure for installation of a beneficiating plant. Preliminary conferences with mine owners to determine what was necessary to place this district into operation were held in the fall of 1950, and were continued during early 1951. As a result, an integrated program for the development and production of manganese in these two districts has been worked out, and contracts in preliminary form have been sent to the operators involved. The price to be paid for the ore and the total cost of fee to be paid for the milling is geared to a fixed price per unit. This has in turn been based on the operations which were conducted for Metals Reserve Company during World War II. It will enable the mine operators to mine and sell approximately the same grade of ore that they obtained previously. The relatively high cost of the product obtained from this area is due to the fact that underground mining, a low average grade of ore, and relatively poor recovery is involved. In spite of the high cost, this project was recommended because it can contribute significant quantities of manganese ore during 1952 and 1953, when the greatest shortage exists. Deming-El Paso It has long been recognized that significant tonnages of manganese oxide ores exist in the area surrounding Deming, N. M. Reserves estimated to amount to at least 200,000 long tons, averaging 15 to 25 percent manganese, are known to exist in the Lake Valley and Manganese Valley mines. Small tonnages can also be obtained from other deposits throughout New Mexico and eastern Arizona. In addition, about 40,000 tons of ore which will be suitable for treatment are available in a Metals Reserve Company World War II stockpile at Deming. In addition to the deposits known in the vicinity of Deming, it has been proposed by Denver Equipment Co. and International Mining Co. to install facilities at El Paso, Tex. for the stockpiling and beneficiation of ores from northern Mexico. Deposits in this area have contributed small production for many years, and it is believed that larger quantities of ore can be obtained from them under proper stimulus. The form which the proposal takes in respect to El Paso is that ores, principally if not wholly from Mexico, delivered to El Paso by applicant shall be bought by the Government at a negotiated price and milled for the Government in a privately owned mill erected and operated by applicant under DMA assistance. The loan necessary for the purpose will be repaid out of fees collected for milling. Purchase of ores can start immediately. Production from the mill should be forthcoming by the end of fiscal year 1952. The outlook for a supply of Mexican ore and plus the Deming backlog justifies immediate construction of the El Paso mill. In respect to Deming, it is proposed that the Government promptly institute a district purchase program, applicable at the same price to all manganese ores offered meeting metallurgical specifications, with a price schedule based on the formula $1 per unit for 20 percent ore plus or minus 2 cents per unit for each percent of manganese contact above or below 20 percent with appropriate limitations dependent on metallurgical consideration. Batesville The Batesville project is one involving ore-bearing clays, and presenting a very different problem from the hard-rock mines in the West. The clay must be milled as fast as it is mined and requires mill facilities at the start. One such project has been approved in principle, at Batesville, Ark., and there are similar deposits elsewhere in the South and Southeast which could be developed if the success of this one is demonstrated. The ore-bearing clays do not usually contain over 5 to 6 percent of 40 to 46 percent manganese, but mining and milling costs are relatively low and there are immense quantities of the ore-bearing clays available. Small quantities of high-grade ore, often running to 70 percent manganese, are shipped from several localities, but constitute an extremely small precentage of the total available by milling methods. New small mines Small purchase contracts up to 5,000 tons will be let by GSA to small producers in several parts of the United States and particularly in the South and Southeast. In addition to these purchase contracts at above-market prices, production loans for operating capital and small outright loans for installation of milling facilities and certificates of necessity for accelerated tax amortization may be necessary in various cases. This small production can be obtained and should be contracted for at prices up to but not exceeding $2 per long ton unit. Artillery Peak, Ariz. Intensive exploration of bedded manganese deposits in the vicinity of Artillery Peak, Ariz., was carried out by Government agencies and by private companies during and after World War II. This work demonstrated the presence of many millions of tons of manganese oxide ores averaging 5 to 15 percent manganese. Still larger quantities of very-low-grade ores averaging less than 5 percent manganese are known. This resource has long been regarded as an important element of any program designed to supply a large part of our manganese needs. With this in view the Bureau of Mines requested and obtained a $600,000 appropriation for the installation of pilot-plant facilities for the final research in metallurgy necessary to put this project and others into operation. Construction of that facility at Boulder City is now under way, and operations are expected to begin late in 1951 or early 1952. Recent improvements in flotation technique of wad type ores of the character present in this area give additional promise that operation of this deposit can be carried out successfully. RESEARCH The Vast quantities of low-grade manganese-bearing material are known to exist in and beneath the iron-ore bodies of the Cuyuna Range. Recent appraisal of this resource indicated that the amount available may be of the order of magnitude of several hundred million tons averaging about 5 percent manganese. All of this is close enough to the surface so that it can be operated by large-scale open-pit methods in the same way as the iron ores. Part of the reserves are in the form of oxidized low-grade manganiferous iron ores; a much larger part is in the form of manganiferous slates from which the iron ores were derived. amount of manganese available from this deposit is believed to be the largest obtainable in the United States except for the extremely low-grade deposits near Chamberlain, S. Dak. Inasmuch as the Cuyuna area could supply a very large part of our needs for manganese, and because of its strategic location with already established lines of communication and a well-established mining industry it is particularly desirable that research leading to a practical means of recovering manganese from this material be undertaken. It is probable that the iron associated with manganese can also be recovered. Research to determine metallurgical methods most suitable for application to these deposits will be undertaken by the Bureau of Mines in the Boulder City pilot plant as soon as research on the Artillery Peak project is completed. It may be desirable also that private research organizations be given contracts to make independent studies of this problem. The problem is so important that $1,000,000 should be allocated for research. LOAN REQUIREMENTS There is no more important a manganese project than the slag program. The successful recovery of manganese from slags, for re-use, has been sought for 30 years or more both in foreign countries and the United States; if successful it should cut the need for imported ores by around one-half and end our precarious dependence on foreign manganese. The Bureau of Mines has. carried its research and development of this program to the point that it now has a pilot-scale blast furnace "on the stream" at its Pittsburgh testing station. A further marker in the progress of the slag program is the expectation that a private entity will put a 100-ton-a-day pilot plant in operation, using its own funds, within 6 months from today. Certain steel com |