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By C. E. Jordan

The fundamental characteristics of ultrafine chalcopyrite flotation were investigated by the Bureau of Mines to establish techniques to improve recovery of ultrafine chalcopyrite. Intense agitation during conditioning was found to improve flotation recovery of the ultrafine chalcopyrite. A split-circuit flotation design, treating the plus 38-µm-size ore by the conventional method and treating the minus 38-µm-size ore with intense agitation conditioning followed by flotation, recovered 95.6 pct of the copper in a 28.3-pct-copper concentrate, This was a 5-pct increase in copper recovery over the conventional chalcopyrite flotation method.

Jan 1, 1986

By L. C. Bartel

Geologic features such as structure (faults, folds, fractures, etc.), water bearing zones, aquifers, pemeability variations, and porosity variations are important for mine planning and in situ energy recovery processes. Features important for planning a mine will be important for planning the recovery of energy by in situ processes. Various geophysical techniques might be used to obtain the necessary geologic information. In this paper, case histories will be discussed of the use of electromagnetic geophysical surveys at a potential underground coal gasification site and a potential tar sand oil recovery site to obtain pertinent geologic information. Results show that the controlled source audio- frequency magnetotelluric technique shows promise for mapping faults and natural fracture systems when there is a sufficient resistivity contrast.

Jan 1, 1982

By W. E. Horst

In Part I of this paper we describe two techniques that were employed in the development of mathematical descriptions of the size reduction process which takes place in a ball mill. In Part II we show how the comminution model was imbedded in a process model to effect steady-state and dynamic simulation of a closed-circuit grinding operation. Increasing emphasis is being placed on development of approaches whereby the essential characteristics of a process can be succinctly represented in terms of a mathematical description of the relationships that exist among important process variables. This activity, commonly known as mathematical modeling, predates modern electronic computers: however, these computers with their tremendous computational capability have given new impetus to the whole field. Although the computer is quite helpful in the development of mathematical models, the real value to the engineer lies in the fact that computers represent such a powerful tool for simulating systems described by mathematical models. As a consequence, engineers may simulate and thereby study the behavior of complex. interacting, systems over a broad range of process variables and configurations once appropriate process models have been developed for the sequence of steps comprising the process.

Jan 1, 1970

By R. L. Sundeen

Trackless vehicles, as the name implies, are machines not bound to rails, guide cables, or other direction controlling devices. They include, for the most part, vehicles which are wheel or crawler (track laying) mounted. Power sources may be self contained such as diesel or battery and can be defined as non-captive machines, while connected power sources such as compressed air or electric can be defined as captive machines. Trackless vehicles are used in all phases of underground excavation, loading, hauling and dumping. Early application found most machines with digging ability used to load those with payload hauling ability. As the versatility of trackless methods became more obvious the trackless vehicle has evolved to more productive machines such as the self loading haulers commonly referred to as Load-Haul-Dump equipment. Trackless vehicles find wide use in drifting and tunneling. Ability to negotiate adverse grades is especially noteworthy. Experience drawn from highly efficient room and pillar mining operations has lead to relatively wide application in drawpoint and cut and fill mining.

Jan 1, 1969

By Roland W. Rammler

In recent years, the crude oil reserves of the world have increased at the same rate as the consumption. A Consideration of the global figures suggests that adequate supplies of petroleum will be available during the next decades. On the other hand, it in a fast of economic and political significance that the reserves in the industrialized countries increase much more slowly than in the developing countries. In Western Europe the reserves have even decreased. At the present time, about 70 % of the petroleum reserves of the world are in the Middle East and in Africa in regions in which political arises are prevalent or impending. For the industrialized countries, the discrepancies between the consumption and reserves in various regions of the world are a strong urge to investigate whether oil can be recovered from other sources. The situation will probably not be changed to a large extent by the discovery of oil in the north of Alaska. The main starting materials for the production of synthetic crude oil are coal, oil shale and tar sand. In North America, where the consumption of petroleum increases more rapidly than the reserves, there are enormous deposits of each of the three materials. This fact is another incentive toward the utilization of these unconventional oil reserves, which provide a reliable basis for a supple of energy for a long time to come.

Jan 1, 1970

By G. H. Gronhovd

The U.S. Geological Survey estimate of the total remaining reserves of lignite in this country as of Jan. 1, 1967 was about 448 billion tons. This represents 27 percent of the total coal reserves on a tonnage basis and about 17 percent on a thermal basis. Approximately 98 percent of these reserves are in a vast lignite field located in western North Dakota and eastern Montana. This field also extends north into the Canadian province of Saskatchewan. Despite these large reserves and relative ease of mining by stripping operations, lignite production historically has accounted for less than 1 percent of the national total. This is largely due to the fact that the lignite deposits are located in an area that has no large centers of population and the economical radius of transportation is limited by its relatively high moisture and low heating value. Commercial utilization of North Dakota lignite for power production became firmly established in the mid-1920's with the development of the first successful lignite-burning equipment. Most of the early lignite-fired boilers were equipped with spreader stokers, but as the size of the plants increased, pulverized-coal firing became the more popular method, and with few exceptions, the plants built during the past 15 years are pc-fired.

Jan 1, 1968

By Samuel S. Adams

Economic concentrations of potassium are essentially limited to thick, stratigraphic sections of marine evaporites. These deposits were precipitated through the evaporation of sea water in restricted epicontinental seas or in grabens related to continental margin rift systems. Following deposition the deposits were subjected to diagenesis and varying degrees of metasomatism and structural deformation. The origin and characteristics of potash deposits are easier to study and interpret than those of most ore deposits because the phase chemistry of the salt systems is known and the approximate composition of the ore-forming fluid (sea water) can be inferred with confidence. It is particularly helpful that the temperature and pressure of deposition approximated that of present earth surface conditions and the pertinent mineral assemblages can readily be duplicated in the laboratory. The study of these comparatively simple salt deposits provides examples of the practical advantages of understanding the genesis of an ore deposit. These observations, in turn, illustrate the importance of pursuing research on the more complicated magmatic, hydrothermal, and ground-water systems as a means to the more successful exploration for and exploitation of the deposits they have produced. It is the purpose of this paper, therefore, to discuss certain aspects of salt deposit geology as they contribute to exploration and mining through some understanding of ore formation. References to field examples and chemical relations in the salt systems are brief. All examples are more fully discussed, however, in the references cited.

Jan 1, 1970

By A. J. Erickson

In mid 1970, Park City Ventures, a Utah partnership of ASARCO and TAC, initiated a six phase exploration and development program in the Park City District, Utah. Geologic studies had delineated a number of exploration tar¬gets in several areas of the district. Discovery of ore in any of the target areas and continued favorable down dip development below then productive ore bodies would allow for reserve expansion and mill construction. The targets were: Mississippian Humbug Formation replacement mineralization below productive ore bodies on the east flank of the Park City Anticline; Humbug replacement mineralization in an unexplored fault block in the footwall of the Hawkeye structure on the east flank of the anticline; vein and replacement mineralization along the Silver Fissure; potentially higher grade Humbug replacement mineralization in a theorized structural block on the west flank of the anticline beneath the Ontario Vein; Permian Park City Formation replacement mineralization in the West End Shaft Area of the Silver King mine; vein mineralization along the Back Vein in the Judge Mine. Chilean Nationalization in 1971 resulted in a 30% budget cutback. The Judge and Silver King Projects were suspended. In spite of the cutback additional reserves were developed below the Humbug East Flank ore bodies; a major zone of ore grade mineralization was discovered along the Silver Fissure; five new ore bodies were found in the Humbug, and Doughnut Formations on the west flank of the anticline beneath the Ontario Vein. First concentrates were shipped from a new mill in May 1975.

Jan 1, 1976

By Wallace W. Wilson

It scarcely 1s possible to read a new issue of any of the principal mining trade journals without noting some mention of a major new overseas mining venture with which one or more domestic companies are involved. These projects seem to follow a fairly consistant pattern; most are large open pit mines, with relatively low grade ore bodies but huge reserves; the total price tag will be in nine significant figures and around half or more of the total cost will be for infrastructure. West1 noted that nearly $7 billion is being invested annually for new mining projects and the expansion of existing mining ventures, in the free world. He anticipates that by the year 1975 such investments would reach the $10-11 billion annual figure, and that in the five year period 1972-76 total capital requirements can be expected to aggregate around $45 billion. The proportion of this total investment which will be financed in some manner is difficult to estimate because of the variety of available financing arrangements. West estimated that around 75% of the total capital would come from internally generated funds, with the balance from external sources. Conceivably a substantially higher percentage could be attributable to external financing, especially it the trend of recent mineral development in Canada and Australia is any criterion, and of course, including local sales of equity as a part of the package.

Jan 1, 1973

By James F. Lemons

The potential production of cobalt from nickel sulfide deposits in Canada, from nickel laterite deposits in the Pacific Islands, and from the copper deposits of Zaire and Zambia will be a function of the cost of recovery of the primary nickel and copper products. This cost of production varies significantly for these deposits and is related to the differences in the cost of labor, energy, and supplies, to production technology, and to the grade and recovery of nickel, copper, and cobalt. This Bureau of Mines paper investigates these cost and technology differences as they relate to the cost competitiveness of the deposits in Canada, Zambia, Zaire, and the Pacific Islands.

Jan 1, 1984

By Helmut Goehring

Surface mining has been used primarily where deposits of minerals were exposed or close to the surface. Surface mining can, therefore, be considered the oldest branch of mining. As the most accessible deposits became uneconomical because of the lack of suitable high capacity conveying systems, deep mining took its place. Only in the twentieth century was this trend reversed as high capacity production and conveying systems were developed. This rapid development was triggered by the steadily increasing demand for raw materials and fossil fuels, as well as by the ever increasing ratio between overburden and deposits.

Jan 1, 1982

Adequate ventilation of coal mine working faces is the single most important technique for controlling respirable dust and methane. Choosing the right technique presents some tough questions. Bureau research has shown that to control respirable dust you must contain the dust near the face, keeping rollback (turbulence) to a minimum. For methane the most effective approach has been to use a blowing brattice or tubing and to create turbulence and disperse the face methane, allowing it to pass over the machine and into the return. It is immediately apparent that the two approaches may counteract one another, thus complicating the decision as to which system may be best for a given situation. At present, Bureau research has developed two successful machine-mounted face ventilation systems to meet these different needs and allow deeper cutting. The fan-powered dust scrubber is designed to control dust primarily associated with blowing face ventilation systems. The spray fan controls methane on exhaust-ventilated sections.

Jan 1, 1988

By G. R. O?Neil

The justification for a "ligand- selective' approach to fine mineral beneficiation via flocculation is established initially. Special emphasis is placed upon the need to identify non-selective, interfering and complicating adsorption effects. Specific strategies directed towards the design and synthesis of complementary selective flocculants are detailed using a number of different polymers and chelating agents as examples. In this regard, the affinity of polymer-bound ligands for metallic cations, ligand concentration, possible modes of attachment, the application of spaced-out ligands and other considerations in the preparation of selective flocculants are highlighted.

Jan 1, 1983

By T. P. Meloy

In the last decade increased and prolonged interest has been displayed in the use: of tunneling or rapid excavation to solve many of the urban and industrial problems confronting our society. There has been talk and action on the interurban rapid transit systems for major cities, and even preliminary designs for a Boston to Washington interurban transit system. Much of this interest stems from the search to the solution of our increasingly complex urban problems, where the surface area must be given over more and more to the inhabitants, and the subsurface for transit, utility and other services. While tunneling is not a panacea to urban ills it holds a real solution to many existing problems. There is also, among the tunneling experts, a growing confidence that technical problems of rapid tunneling can be solved. To solve these problems, R & D money must be invested. If it is to be money invested either by private industry or governments, there must be significant returns on the investment to justify the research and development need to bring about the breakthrough that will make tunneling a major contribution to the solution of urban problems. To make these economic studies more extensive and more accurate tunneling demand figures were needed. To this end, the Organization of Economic Cooperation & Development - OCED - included in its Conference on Tunneling a section on tunneling demand. As a result of the conference the organization for Economic Cooperation and Development issued a report entitled "The Advisory Conference on Tunneling - Report on Tunneling Demand 1960-1980. " This report was presented at the OCED Conference on Rapid Excavation, held at Washington, D.C. To obtain the data in the Report, questionnaires were sent to the OCED countries and 18 replies were received from Australia, Austria, Belgium, Canada, Denmark, France, Germany, Ireland, Italy, Japan, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom, and the United States. While it is true, that data were missing, that sometimes the definitions were confused, and that several countries provided no cost estimates at all, in general, this report contains the most comprehensive gathering of data that ever existed in the field. All data in the OECD report is expressed in terms of meters or cubic meters, and costs are in U.S. dollars.

Jan 1, 1970

By Earl R. White

In 1950 Kaiser Steel Corporation acquired control of the Utah Fuel Company, a pioneer Utah coal concern owning large reserves of high volatile coking coal near Sunnyside, Utah. The mines at Sunnyside have been producing high quality coking coal since the late 1890's. Kaiser Steel acquired the coal deposits at Sunnyside in order to supply the necessary coke for its steel plant at Fontana, California. The Sunnyside coal deposits are made up of two mineable beds, the upper and lower Sunnyside seams. Both seams outcrop along the southward facing escarpment of the Book Cliffs. The coal seams dip under the massive sandstones of the Book Cliffs to the northeast at 5 to 22 pct., with the steepest-part being near the outcrop. Mining at Sunnyside up to 1961 had been carried on with room and pillar methods. The deep cover and rotten roof conditions, along with the need of increased tonnage, required a change of mining technique. Numerous ideas were presented, discussed, and economically analyzed. Several people involved in these discussions, with the aid of W.W. II, had been introduced to the European methods of coal mining, namely the longwall technique. The European mines had long been plagued with near similar conditions as those at Sunnyside, particularly the deep cover problem. The longwall method seemed to be working very well under these conditions, and with the extensive studies given longwalling by the Kaiser Steel mining officials, it was decided to give longwalling a try.

Jan 1, 1976

By William E. Lamont

As a part of the Department of the Interior's rutile and titaniferous materials development program conducted under the Defense Production Act, the Bureau of Mines investigated the potential for producing national stockpile grade rutile from plant products of phosphate beneficiation plants operating in the central Florida pebble phosphate district. The potential for producing ilmenite, zircon, and monazite concentrates from the plant products was also investigated. Results of these studies indicated that 3,000 to 6,000 tons of rutile, 28,000 to 55,000 tons of ilmenite, 9,000 to 19,000 tons of zircon, and 400 to 800 tons of monazite passed through the plant circuits annually. All of these minerals are presently being sent to waste ponds. Beneficiation of a bulk heavy mineral concentrate separated from the amine flotation tailing (froth product) of numerous plants in the district showed that it was possible to produce a rutile concentrate containing over 94 percent Ti02. Additional studies showed that over 70 percent of the Ti02 in the rutile concentrate could be isolated in a product containing 98.0 percent Ti02. The studies also showed that it was possible to produce ilmenite concentrates containing 63 percent Ti02, zircon concen¬trates containing 65 percent Zr02, monazite concentrates containing over 85 percent monazite [(Ce,La,Y,Th) (P04)], and xenotime concentrates containing over 35 percent xenotime (YPO4).

Jan 1, 1969

By D. S. Dick

Over the last few years, new methods to characterize the flow properties of bulk solids have been developed. Abrasive wear and particle attrition can now be accurately measured in a laboratory and scaled up to field conditions. In addition, the effect of large particles on a material's flow properties (cohesive strength, bulk density, wall friction) can be determined as well as the effects of various additives such as Freeze Conditioning Agents. New developments have also taken place in terms of devices to improve the reliability of solids flow. Much attention has been paid to finding ways to provide a mass flow pattern with relatively shallow hopper walls through the use of inserts. Such devices can also provide reliable in-bin gravity blending of bulk solids and/or completely non-segregated discharge. Other developments have occurred in the area of belt-to-belt transfer chutes and sealing screws. Many of these developments have direct application in the mining and minerals processing industries. Examples of each will be highlighted.

Jan 1, 1988

By Hugh McMillan

To protect the water supply for the Metropolitan Chicago area, the Illinois legislature, in 1889, created the Metropolitan Sanitary District of Greater Chicago. To insure the quality of the water supply, the Sanitary District collected and diverted the wastes of 750,000 people away from Lake Michigan. Today, the Sanitary District collects and treats the wastes from a domestic population of 5 ¼ million people and an industrial waste load equivalent to 4 ¼ million people. The District serves Chicago and 120 other cities and suburbs in an 858 square mile area. An average of 1300 million gallons of wastewater is treated each day, producing as a by- product about 700 dry tons of solids which contains more than $10,000 worth of plant nutrients when equated to the value of commercial fertilizer purchased in the retail market. The Sanitary District considered several alternatives to past methods for disposing of these solids, and chose land application as a technique to utilize the solids produced by the wastewater treatment process in a beneficial manner.

Jan 1, 1973

By R. R. Young

Prior to 1903, the world's supply of sulphur was primarily from surface deposits in Sicily. The discovery of the first salt dome sulphur deposit in 1867 and successful development of the Frasch process for recovering the sulphur resulted in a large part of this essential element being supplied from these mines since 1920. Although the basic process is the same today, engineering and technological developments have evolved to allow its application under many adverse conditions. These and other challenges for the industry in today's environment will be discussed in the paper.

Jan 1, 1979

By J. R. Dillon

Today more than ever, there is an increased demand for higher plant production capacities and efficiencies to offset the increasing costs for labor and materials. Plants involved in processing large volumes of bulk materials are particularly interested in more efficient material handling systems to (1) reduce labor and maintenance costs, (2) improve blending of non-uniform raw material feed to processing facilities, (3) improve blending of finished bulk materials from storage. DragScraper systems are being used effectively for handling a variety of bulk materials in both indoor and outdoor storage. Materials being handled include ores, chemicals, coke, clay, and stone, to name a few. Handling capacities these machines can provide vary from a few tons to over 1500 tons per hour. The basic components of a DragScraper machine consist of a bottomless Crescent scraper, a two or three-drum DragScraper hoist assembly including gas, diesel, or electric power unit, operating cables, guide blocks, and either fixed or mobile head and tail structures. They are presently available in sizes through 15 cubic yards, for operating spans up to 1000 feet.

Jan 1, 1969