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By Peter C. Badgley

Three tectonic provinces within the Cordilleran System, are analyzed in terms of tectonic framework. (1) Precambrian terrain of North-Central Colorado; (2) The Pacific Northwest; and (3) The San Andreas-Garlock fault system and associated features. In each case a close relation- ship is seen to exist between: (I) Arcuate mountain development; (2) Precambrian basement fabric; (3) Major fault patterns; and (4) Major mineral occurrences. The arcuate trends developed when the basement was still mobile. Later competent deformation rejuvenated pre-existing lines of weakness. Because of the pre-existing arcuate framework, the rejuvenated faults frequently act as conjugate shears (strike-slip faults) flanking the old arcs. The conjugate shears intersect to form wedge- shaped plates. When such plates move forward along boundary strike-slip faults in response to post basement orogenic forces, new secondary fracture systems are generated in the country rock flanking the advancing wedge. The apex regions of the wedges are particularly favorable for detailed exploration.

Jan 1, 1959

By K. E. Laughery

The Nevada Barite industry has experienced a 277% growth over the last five years with a total production of 2,542,000 tons. Total production prior to 1970 approximates 2,700,000 tons dating back to 1907 Annual production, as can be seen in Table 1, has increased from 192,000 tons in 1971 to 723,000 tons in 1975. During this same period U.S production has increased from 825,000 tons to 1,056,000 tons. Nevada is now the leading producer with 69% of the market. The increase in the Nevada barite production is, of course, directly related to the increased demand for weight material coupled with the lack of other sources and the relative economic advantage of the Nevada barite, A significant tonnage of Nevada barite is utilized in the non-oil well market, principally at FMC's barite chemical plant at Modesto, California; however the growth has been in the oil well market.

Jan 1, 1976

By T. C. Vogt

The past history of uranium production has been dominated by strip and shaft mining methods, but recently in-situ leaching has emerged as a viable alternative for uranium recovery. (1-8) Mobil was the first company to start in-situ uranium leaching in New Mexico. Mobil's Crownpoint project areas are in Mdinley County and are part of the Grants Mineral Belt. The major uranium deposits in this area occur in the Westwater Canyon Member of the Jurassic Morrison Formation. (9-11) The ore depth at the Crownpoint project is about 2000 ft. In an earlier paper we discussed the uranium mineralogy of an areally broad sampling of Crown- point ore. (12) The organic carbonaceous material often associated with the coffinite ore was characterized in some detail. The organic material appeared to be a very mature, coaly-type kerogen derived from plant components. This result was consistent with other studies on such carbonaceous material. (13-15)

Jan 1, 1981

By Diane Jones, Jeremy Spearman, Tom Matthewson

Requirements for minerals are on the increase globally and the deep sea offers a potential source of essential materials. Extracting these minerals from what is considered an environmentally sensitive area, and one about which little is still known, is a challenging activity, which needs careful consideration and an appropriate environmental impact assessment to be carried out. Extraction of material from the deep sea beds can cause disturbance or damage to benthic communities; impact on mobile marine species such as fish, mammals and reptiles; cause increases in suspended sediment and sediment deposition onto potentially sensitive areas or potentially release contaminants which were previously bound to the sediment. This paper discusses the potential environmental issues surrounding extraction of deep-sea deposits using aggregate dredging techniques and how those issues can be appropriately assessed. In particular issues of suspended sediments, plume transport, water and sediment quality and underwater noise impacts on potentially sensitive species and habitats will be explored.

Sep 1, 2014

By A. S. Ibrado

The adsorption of silver on activated carbon from cyanide solutions was studied as a function of concentration, ionic strength and pH. In cyanide solutions, silver exists mainly as the linear Ag(CN)2 complex and adsorbs on activated carbon following the Freundlich isotherm. The uptake and rate of adsorption increase with the addition of KC1 and KNO3 but changes only slightly with pH. In contrast, the adsorption of Cu(I), Zn(II), Cd(II), and Hg(II) shows marked changes with pH, closely following the predominance profiles of their neutral and singly-charged cyano complexes. Clearly, multicharged negative complexes are repelled by the negatively-charged carbon surface. This sensitivity of activated carbon to the charge of the adsorbing species indicates that silver adsorbs as an anion, not chemically bound to the co-adsorbing counterions. For the same reason, activated carbon is selective to metals that form neutral and Singly-charged cyano complexes, namely gold and silver.

Jan 1, 1988

By K. P. Bingham

Lime is one of the largest volume chemicals produced in the United States. In 1979 approximately 21 million tons were produced. Lime is, in fact, second only to sulfuric acid as the largest volume basic chemical produced. Lime, also known as quick lime (calcium oxide) and hydrate lime (calcium hydroxide), is the principle alkali used in a multitude of industrial processes. In addition to its use as a principle industrial alkali, lime has experienced dramatic growth in four general market areas during the past 30 years. These four areas are: 1. Water Treatment - Lime is used extensively in treating and purifying water for industrial and potable use, Although significant tonnage is shipped to this market of municipal and industrial water treatment plants, the end-users are widely spread geographically and individual shipments are relatively low tonnage. Lime, which is nonhazardous, can safely be shipped by truck or rail to these small end-users. 2. Municipal and Industrial Waste Treatment - Environmental agencies at all government levels,

Jan 1, 1980

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

The Mesabi Range extends continuously from near Grand Rapids, on the Mississippi River, E.N.E. for a distance of about 1120 miles to near Birch Lake, where it is covered by the large gabbro flow which forms the base of the Keweenawan series. The same formation (Mesabi) appears again near Gunflint Lake on the international boundary, and shows as far east as Thunder Bay on the north shore of Lake Superior. Between Mesabi station, on the Duluth and Iron Range Railway, and Birch Lake, although considerable exploration work has been done, there is no evidence of concentration of ore in workable bodies. The Gunflint beds are thin alternating layers of chert and hematite. Alt the workable deposits at present known, on the Mesabi, lie between Mesabi station and Grand Rapids, the greater number being St. Louis County simplified geologic column is given herewith instead of the complete correlation table given by the United States Geological survey.

Jan 1, 1920

By Raj K. Singhal

Canada produces close to 42 million tonnes of coal per annum of which some 38 million tonnes is produced by surface mining methods. The two Western Canadian provinces, Alberta and British Columbia, produce 31 million tonnes of coal by surface mining. These two provinces provide the bulk of the metallurgical coal for export. The geological conditions in the Western provinces particularly in the mountain region are complex. The coals are friable and the seams are steeply inclined, sheared, intensely folded and faulted. There may be as many as 15 to 20 coal seams present with true thickness ranging from 2.5 m to over 8 m. This paper reviews the surface mining methods used to extract such seams. The difficulties associated with steep seam and multiple seam mining of friable coal resulting in lower coal recovery, high dilution and the problem of cleaning fine coal in the wash plant have been highlighted.

Jan 1, 1984

By Unto Paakkinen

The testing of different kinds of process flow configurations and cell volumes in industrial scale flotation processes is in general difficult to accomplish and even expensive to perform.1 Also the lack of suitable measuring and analyzing devices often prevents effective comparison of results. Nowadays, the existing flotation processes contain, almost with exception, several return loads which result in difficult control of the process. There exist two good reasons for testing different kinds of flotation circuits at the Outokumpu Oy Kotalahti mine. Firstly it is easy to change the process flow configuration without any additional installation work and secondly, the concentrator is highly automated with magnetic flow meters, on-line analyzer and process computers. In this presentation, open circuit flotation is compared with the classical closed circuit flotation which contains return loads. In additional, the effectiveness of computer control in both cases is estimated and also the effect of cell volume on flotation results is examined.

Jan 1, 1977

By Noriyuki Fujii

It is no need to say that exploitation of industrial minerals has a close relation to development of the industries related. In the first stage, a small scale manufactures were initiated in areas producing some main raw material minerals. China and cement manufactures, for example, were established depending on the local occurrence of raw materials such as kaolin and limestone without exception. That is, the industrial development is greatly influenced by the local production of the raw materials in the stage. With the development of industrial technology, various kinds of raw material minerals are explored to meet the demands of industries in the second stage. New materials become indispensable, and low-grade raw material minerals, which were left as useless, are developed as useful materials. In the stage, the development of raw material minerals is accelerated by that of industrial technology related. However, industries mainly rely on domestic production of the min raw material minerals.

Jan 1, 1981

By T. D. Oulton

The only known attapulgite clay deposits of any considerable extent and purity in the United States are roughly bisected by the Georgia. Florida state line between Decatur County, southwest Georgia, and Gadsden County, northwest Florida. Although attapulgite clay occurrences both farther East and South are known and have been mined to some extent in the past, at the present time it can be said that substantially: all of the commercial attapulgite clay mining and pro¬cessing is concentrated in a roughly rectangular area some 25 miles long by 15 miles wide,, in the general region of Attapulgus, Georgia, and of Quincy and Havana, Florida. Within this area are located the clay processing plants of the four major producers as well as most, if not all, of the currently active mining operations. The approximate location of the plants and of some of the open mines are shown in the local area map, Figure No. 1, for the purpose of orientation only.

Jan 1, 1965

By Harvey P. Knudsen

Case studies are presented in this paper to illustrate the usefulness and applicability of using conditional simulation in under- ground coal mine planning. Conditional simulation is a technique developed in the last five years that allows the building of a simulated ore body (or coal deposit) model. Construction and validation of the simulated model is described in order to show how well the model reproduces the essential characteristics of the deposit. In the model, the thickness, ash, and sulfur content are known everywhere in the deposit and each variable has the same mean, variance, and spatial variability (variogram) as that variable has in the real deposit. Use of the simulated deposit in the design of drilling strategy for long range mine planning is demonstrated in me case study. Determining the potential of short term production scheduling to reduce the fluctuations of sulfur in run of mine coal is described in the second case study.

Jan 1, 1980

By N. K. Bohidar

Evaluation of the stability of a structure under given boundary conditions requires accurate knowledge of the state of stress as well as the mechanism of failure at the critical state of stress. This paper represents a part of the research done by N. K. Bohidar during 1965-1968 for his Ph. D. research in Mining Engineering at the University of Utah. It summarizes the determination of internal stress and failure phenomena around cylindrical openings in viscoelastic media subjected to lateral restraint and vertical uniaxial load. The conditions of lateral restraint and viscoelastic nature of the media represent conditions associated with subsurface openings in rocks. The financial assistance provided to the project from the University of Utah Research (Uniform School Fund), W. C. Browning Scholarship Fund, Earth Science Research Fund, and D. C. Jackling Loan and Scholarship Fund is gratefully acknowledged. The authors also acknowledge the assistance of S. Siugh, W. Jones, and K. McCarter during the project.

Jan 1, 1970

The Department of Health and Human Services (HHS), National Institute for Occupational Safety and Health (NIOSH), Office of Mine Safety and Health Research (OMSHR), with the assistance of cooperating underground mining operations and state agencies, has conducted research exploring devices and technologies that could be used to assist miners navigating through smoke and dust resulting from a fire or explosion. Recent events in mines confirm that smoke and dust can enter and contaminate mine escapeways creating an atmosphere with severely reduced visibility. This reduced visibility results in substantially increased escape times, possible disorientation or confusion, and increased stress levels, and may prevent evacuation altogether. Tools or devices that assist miners in navigating through smoke-filled areas void of lifelines could make the difference in successful escape from the mine. This paper presents the results of OMSHR research to identify and evaluate tools and devices that could provide meaningful information to evacuating miners in areas with limited visibility and without the benefit of a lifeline.

Jan 1, 2011

By Allan M. Johnson

Dewatering is a major operational cost at sane mines. Under certain conditions, costs associated with water disposal may continue beyond the productive life of the mine. For mines with mineralized waters, this is of special concern. Since 1974 experience has been gained from the examination of a number of closed underground metal mines that exhibited drainage problems. It was observed in certain cases, that had appropriate steps been taken prior to closure, that the resulting drainage problems could have been largely avoided. The pre-closure steps would have involved alteration to the "plumbing system" of the mines: i.e., the drifts and crosscuts interconnecting the workings of the mine. This could have best been accomplished by the placement of bulkheads and/or selective drifting. In addition to reconfirming that hindsight is 20-20, a lesson learned from these case studies shows that a relatively simple hydrologic evaluation prior to mine closure may avoid a troublesome and costly drainage problem.

Jan 1, 1983

By Robin Adams

After nearly five years of economic hardship, the world copper industry is, in our opinion, about to enter a period of considerable strength. This opinion is based on three main propositions, namely: 1) there are a number of reasons, both general-economic and industry-specific why copper demand is likely to perform significantly, more strongly in the 1980's than in the 1970's; 2) the virtual cessation of investment in new facilities, especially at the mine level, over the past years makes it physically impossible for capacity to expand as fast as demand in the mid-1980's; and 3) there is much less "excess" inventory available than most analysts believe. If we are correct in these assumptions, then the implication is that copper prices will climb up to, and possibly beyond, the cost-justified price level. Combined with general inflation, this suggests a price in excess of $2/pound by 1985 or roughly treble the 1978 average.

Jan 1, 1979

By Tony Stephens

In this paper I will try to give an overall picture of the use of pure oxygen in gold leaching in South Africa. Pure oxygen has been overlooked as a reagent for many years. Only with the increased sophistication of gold plant instrumentation, greater recognition of the technical abilities of the plant management and a more definite attitude towards plant efficiency has the recent break-through been achieved. There are, today, twelve plants using pure oxygen in this way as a permanent part of their operation and another three or four presently carrying out long-term evaluations. I believe that this number will double over the next few years as more and more plants identify potential benefits. I have, therefore, set out to look at the background and chemistry behind these innovations, describe the various methods available to dissolve oxygen, briefly look at the laboratory and trial work carried out by ourselves at Afrox and then the different installations, both ours and those of our competitors.

Jan 1, 1998

By Jr. Abel

Subsidence is controlled by a complex combination of mining and geologic factors. For example, a world-wide compilation of data shows that, as the percentage of shale in the overying rock mass decreases and the amount of sandstone increases, the angle of draw (and the area affected by subsidence) decreases. Limestone in the overburden appears to cause as much as a three-fold decrease in the angle of draw compared to a like amount of sandstone. Increased amounts of sandstone were accompanied by a greater surface subsidence relative to the mining height. The total thickness of overburden did not appear to influence the subsidence magnitude above super-critical panels. The greater the thickness extracted the smaller percentage of that thickness that shows up at the surface as subsidence. The greater the percent of the seam extracted, the greater the subsidence reaching the surface. The maximum subsidence above room and pillar panels is dependent on the pillar height and minimum width as well as the other factors listed.

Jan 1, 1980

By G. L. Barthauer

It is a distinct privilege to have the opportunity of addressing this group today. Although I, myself, am not a mining engineer, I have always had profound admiration and respect for those of you who each day live and work according to the tenets of Murphy's Law. Murphy, as some of you may know, was an Irish philosopher whose sole contribution to his field was the observation, "In the mining industry, if anything can possibly go wrong, it will!" You have heard this afternoon a variety of papers, touching on or describing in some detail imminent problems which presently face the coal industry. Many of these problems show no signs of diminishing. Actually, there is good reason to believe that they will intensify as governing bodies pass additional enabling legislation and regulatory agencies adopt more stringent "Rules and Regulations". In many cases, these groups are seemingly oblivious or indifferent to either cost factors or technical problems involved in achieving the desired goals.

Jan 1, 1967

By B. R. T. Simoneit

The formation of petroleum is normally thought of as a geologically lengthy process, involving the accumulation of organic matter, its gradual burial, diagenetic breakdown via geochemical reactions, maturation, heating within a 75-150'C "oil window" induced by normal geothermal gradients in the subsiding basin, and slow product migration into structural traps (Tissot and Welte, 1984, Hunt, 1979). The entire process can take millions of years and, indeed, most oil reservoirs probably formed in this manner. How-ever, today in sedimented, submarine rift basins (Fig. 1), Cl to >C40 hydrocarbons with the chemical and physical properties of crude oil are forming in demonstrably much shorter time by rapid thermal maturation of immature organic matter in hydrothermal regimes that are unusually high for sedimentary basins (Brault and Simoneit, 1988a, b; Didyk and Simoneit, 1988; Kawka and Simoneit, 1987; Peter et al., 1988; Simoneit, 1983; 1984; 1985a,b; 1988; Simoneit et al., 1984; 1987; 1988).

Jan 1, 1989