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By KAGAN BENZESIK, OMUR CAN ODABAS, SELCUK KAN, Onuralp Yucel

In this study, domestic molybdenum disulfide (MoS2) concentrate was roasted in a chamber furnace and then in a rotary kiln. The behavior of the roasting process was examined in both furnaces, and which type of furnace is more advantageous to use in mass production was investigated. It is theoretically possible to roast in a chamber furnace, but a major problem was observed when the amount of concentrate was increased in the chamber-furnace experiments. The problem was solved by using a rotary kiln. This study improves the understanding of the roasting of  MoS2 concentrate and presents a different perspective to the industry, showing that rotary kilns can also be used for roasting.

By Jon J. Kellar

The adsorption of oleate at the surface of a fluorite single-crystal internal reflection element has been investigated using Fourier transform infra-red/internal reflection spectroscopy (FTIR/IRS). The application of this innovative experimental technique has added a new dimension to the investigation and understanding of collector adsorption phenomena. It is now possible, for the first time, to measure in-situ and in real time the adsorption density and bonding nature of collector species adsorbed at mineral surfaces. In this regard, oleate adsorption densities were calculated from spectral data, and the equilibrium adsorption isotherms were found to agree quite well with other adsorption isotherms reported in the literature. At low equilibrium oleate concentrations(<10-5 M), monolayer-type cover-age was observed in the chemisorbed region. It was found that in this region the adsorption density increases with an increase in temperature, which sup-ports experimental results from previous ex-situ FTIR studies and thermochemical studies in which it was shown that the chemisorption reaction was endothermic. At higher equilibrium oleate concentrations (>10-5 M), the adsorption density increases dramatically at the point of surface precipitation. The oleate adsorbed in the chemisorbed region has a distinctly different spectrum than the oleate adsorbed in the surface precipitation region of the adsorption isotherm. In the chemisorbed region, the oleate appears to be mono-coordinated at the fluorite surface.

Jan 1, 1989

By Kenneth J. Reid

The application of computers for control purposes in hydrometallurgical processes is not as well-established as in mineral processing plants. This is not only due to the comparatively new development of large-scale application of hydrometallurgy and the relatively small number of operating plants, but also due to some of the basic dynamic characteristics of hydro- metallurgical processes., Basically there is little difference in the development and application of digital control techniques in hydrometallurgical plants from those techniques widely in use throughout the chemical process industry and in nonslurry applications; particularly for those cases involving liquid streams only, the primary sensing elements are essentially the same. On-stream X-ray fluorescence analysis is a well-established method for determination of metal content in the process streams, and standard equipment is used for the measurement and control of pH, flow, density, temperature, pressure, and other variables. Nevertheless, the high proportion of corrosive slurry streams at elevated temperature and pressure poses a challenge to the instrument engineer concerned with developing long-life, reliable instrumentation. One major difference and potential problem area in developing control systems for hydro- metallurgical processes is related to the very long time constants which are common in the larger plant. In these circumstances, it is important to define the overall control objectives very carefully and be prepared to allow for considerable drift in intermediate variables. In larger projects with many control loops the general advantage of lower costs compared to conventional analog instrumentation can be confidently expected. Also in most cases, the process analysis necessary to design and specify a comprehensive computer control system and the increased operator involvement in implementing digital control systems yield additional benefits due to the increased understanding of the dynamic characteristics of the process.

Jan 1, 1979

By D. C. Wilder

Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed. but neither sheared nor faulted. Furthermore. thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling thus a permament deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper (Butkovich and Patrick, 1986a) indicates that deformations in un- sheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity re-adjustments during thermal deformations. micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads.

Jan 1, 1986

By J. Kallioinen

Theoretical considerations, experimental results and plant experience have lead to a new design concept called the unit reactor approach. It has been successfully implemented to the largest flotation cell on the market, the 4000 cu ft OK TankCell. The work has also lead to a new operating idea called size specific flotation. The paper discusses these concepts in the view of full scale field experiments. In large scale porphyry copper flotation experiments conducted in Chile the new large TankCell with its new low energy input Free Flow mechanism out-performed the more conventional designs. The recovery was substantially better, especially in the coarse fractions. In some experiments the difference in total recovery was up to 10%-units and the savings in total energy consumption at the same time over 40%.

Jan 1, 1995

By Y. Luo

Based on the concept of slope stability analysis, a formula for determining an important parameter required in the mathematical model for the prediction of mining subsidence in hilly terrain has been proposed. The slope geometry and soil physical and mechanical properties of the surface natural slope can all be considered in the formula. Incorporation of this new formula into an existing mathematical model provides an integrated approach in studying ground movement in hilly regions.

Jan 1, 1998

By Zeynep Aktuna

In this study, the formation of zeolites around Kizkapan and Karlikoy villages (Sothwest Kesan) were investigated. In this region, stratigrafically, Upper Eocene Kesan Formation, i.e. sandstone and rarely shale are observed at the bottom. Early Middle-Oligocene Yenimuhacir Formation is composed of sandstone, marl and tuffs. The zeolitisation is determined in the dasitic tuffs of the Yenimuhacir Formation. In this tuffs&apos; zone, alteration had primarily resulted in zeolites, mainly mordenite, heulandite-clinoptiIolite. Silicification and alteration to clay minerals are also common. The Miocene-Pliocene Ergene Formation and alluvium deposits are the top units in the area. In the studied area, zeolite occurences have economic importance. The results show that successively rapid and short term periods are responsible for the clinoptilolite-heuylandite formations. The homogene chemistry of the solutions may be evaluated for a possible successive zeolitisation period. Multi-periodic vocanic activity and also circulation of thermal water had resulted in a continous dissolution of volcanic glass; moreover, resulted in the formation of suitable conditions of zeolite formation. The mineral crystallization sequences and alteration products as zeolites within the wall-rock, circulated solution reaction depends on a serie of parameters such as chemical composition of both initial materials and volcanic solutions during rock¬solution interaction period. The previous researches and the chemical studies support our results and observations in the studied area. The aim of this study is to investigate the presence of zeolitisation and to explain the formation steps of zeolitisation in Kesan Area by considering the content and distribution of major and minor elements determined in zeolite bearing tuffs. The chemical structures of both zeolite bearing volcanics and zeolite minerals are compared to the results of previous studies. Two dimentional behaviours of major and minor elements were discussed in order to caracterize zeolitisation development and to postulate a probable formation type of zeolitic alteration.

Jan 1, 2005

By Charles W. Merrill

The price records of 7 representative mineral commodities for the 68-year period 1890 through 1957 have been compiled and analyzed for significant trends. When reduced to real prices in terms of dollars of constant purchasing power or to the purchasing power of industrial wages at average rates, a substantial overall fall in prices is revealed. This downtrend contradicts the widely held concept that, heavy drafts on a mineral resource must lead to scarcity, reflected in rising prices. Three metals (aluminum, copper, and pig iron), two fuels (bituminous coal and petroleum)&apos;, and two nonmetals (sulfur and cement) have been chosen because of their preeminence in their respective categories, their significance in an industrial economy, and the ready availability of their price records. It might be added that these seven commodities. were selected before any price figures were compiled, none was selected or rejected to substantiate any preconceived notions as to price trends, The overall importance of the seven is demonstrated by the fact that, taken together, they composed over three-fourths of the value of all minerals produced in the United States in 1957. The first step in the analysis was to reduce the price records to a basis for significant comparisons, Two such comparisons have been made: (1) The quantities of each of the commodities that could have been purchased for an average hour&apos;s wage in each year; and (2) the unit price of each commodity through hhe years in terms of deflated dollars. These data are set forth in the accompanying table and two charts.

Jan 1, 1959

By Robert Hochscheid

A patent issued to J.N.J. Leeman (1957) described the change in performance that takes place when a cyclone is installed in the horizontal position rather than the vertical position. Although this patent was directed more toward improvements that could be realized in the heavy medium cleaning of coal, it contained specific references to reducing the quantity of fine solids that would report in the underflow, and an example for fine sand classification is also included. The three cyclone installations for which data is given in this paper demonstrate that horizontal mounting of large cyclones can improve classification efficiency, eliminate some operational difficulties, and reduce cyclone maintenance requirements in closed circuit grinding installations. Cyclone Experience at Serrana S.A. Each of four grinding circuits at the Serrana S.A. de Mineracao Apatite flotation plant in Brazil have a 2.7 X 4.6 meter (9 X 15 foot) rod mill and each originally operated in closed circuit with two vertically mounted Model D20B (500m nominal diameter) Krebs Cyclones. New feed size is 25mm. The Apatite is liberated at a relatively coarse 35 to 28 mesh grind, but the 500mm cyclones had to be fed at 66 pct. solids in order to obtain an overflow analyzing 12 pct. coarser than 42 mesh. Because dilution water in the cyclone feed had to be limited, classification was inefficient, and there were other significant circuit difficulties as summarized in a recent article by C. A. Busnardo (1984):

Jan 1, 1985

By I. C. Watson, J. W. Klokow, A. F. Knoetze, R. G. B. Pickering

In the late 1970s and early 1980s there were a number of attempts to use Tunnel Boring Machines in deep level gold mines. These attempts must be regarded as unsuccessful. Since then there have been comprehensive developments in tunnel boring equipment and tunnel support technology. This paper defines the problems experienced in those early trials, reviews the technology development, and concludes that tunnel boring in deep level goldmines can be justified in today’s environment.

Jan 1, 1999

By S. P. Singh

Drifts are the nerve centre of underground mining. They provide essential communications between primary openings and production areas. In view of their strategic importance in the overall safety, economy and productivity of mines, an empirical approach for blast design during drifting has been proposed in this paper. The approach was developed with the objective of minimum blast damage and provides computerized blasthole patterns for drifting operations. The drift blasting practices and problems in Canadian mines have also been reviewed in this paper.

Jan 1, 1991

By Lawrence A. Browning

In recent years, there has been a growing realization of the importance of ground water as a national resource and increasing concern that this resource be properly managed and protected from a variety of pervasive practices that endanger it. Aquifers have been adversely affected in every region of the country. In dealing w.ith the underground water program, EPA will have the following objectives: to protect human health, and to protect and conserve an important national resource. In pursuing these objectives, EPA will take economic consequences and other national objectives (e.g., energy) into account. EPA intends to pursue these objectives in full partnership with the States. Generally the States should retain the lead in protecting ground water.

Jan 1, 1978

By Harry H. Posey, John Woodling, Miriam L. Renkin

Natural acid drainage is generated from pyritic rock underlying 17 percent of the upper Alamosa River basin. About one-third of these acid producing rocks have nil carbonate buffering capacity; there the streams carry significant acid plus dissolved Al, Cu, Fe, and Zn. In part of the basin, aquatic life is limited by the natural acid drainage. In the four miles where the Alamosa flows through pyritic rock the river grows toxic to trout. Inhospitable conditions continue downstream for at least another four miles. The waters become refreshed, naturally, through metal dilution, metal oxide and hydroxide precipitation, and acid neutralization. Water quality fluctuates in seasonal cycles. Dissolved metals and acid, which are generated year-round by weathering, are stored over winter in the unsaturated zone in the retained water and in soluble metal- sulfate minerals that form by evaporation of acid-metal waters. Seasonal discharge variations cause metal concentrations and pH to shift in the trunk stream; the acid drainage source streams, however, shift only slightly by season. In early spring, metal concentrations and metal loads increase as metals and acid are flushed from the unsaturated zones by melting snow. Peak metal loads occur at this time, and precede peak flow by up to two months. Other metal load peaks occur during peak flow and monsoon flow, even though metal concentrations are diluted at that time by precipitation. In late spring and thereafter, discharge of neutral pH water wanes, so trunk stream pH falls and metal concentrations return to previous high levels. Metal concentrations appear to be low from November through January when dilution from precipitation is lowest, but rise in February to near peak yearly concentrations. In years with high monsoonal flows, metal-laden waters apparently flush from the unsaturated zone and metal concentrations remain low from about October through January. In years with low monsoonal flows, however, metal concentrations in October and November at least are higher.

Jan 1, 2000

By James J. Scott

Shale formations are the Nemesis of the Mining Engineer. Shales react to changes in environment in the most unusual and unpredictable manner. Increase in temperature may cause spalling, increase moisture and compression induced fractures may occur, and if a full face is exposed it may deteriorate due to atmospheric exposure. Combine only small amounts of shale in layered fashion with hard brittle competent rock and the whole structure may be fractured and fail due to stresses generated in and around the shale. In this paper the author will discuss failure mechanisms encountered under various field conditions and remedial action which may be employed by the engineer.

Jan 1, 1969

By Jorgen Elbrond

The mineral industry shares a particularity- heterogeneity-with the other primary industries exploiting nature such as agriculture, fisheries, and forestry, which may not be found in the secondary industries, In the mineral industry heterogeneity is evident both in the raw material, the ore in situ, and in the working conditions. Mining engineering, which encompasses the tools for designing mine production systems, is mostly an assembly of the other branches of engineering and applied science. The assemblage&apos;s goal is to arrive at an optimal production system. As such, mining engineering is similar to systems engineering. The technique for the development of systems-mine production systems or mining operations -is operations research with its succession of activities: observations, modeling, experimentation, and verification. Comparisons among alternative systems are highly desirable during the development phase of a mining operation as well as during later phases where modifications, ameliorations, and expansions are carried out on the existing system. The role of the independent consultant in systems design and development lies in the collection and breadth of experiences from modeling and model verification in other operations, which he can add to a new system&apos;s development and thus in- crease its credibility with management.

Jan 1, 1979

By C. B. Manula

The Crushed Stone Industry plays an important role in Pennsylvania&apos;s mineral economy. During 1965, the total production of crushed and broken stone in the United States reached 780 million tons from which 57 million tons were produced in Pennsylvania (Mineral Industries Surveys, 1966). It is further significant that Pennsylvania is the nation&apos;s leading crushed stone producer. Future trends in stone production will quite likely parallel those in the construction industry. Stone and stone products are finding greater and more varied uses each year. Continued record expenditures for structures such as dams, highways and buildings are the prime reasons for this accelerated growth in demand. Completion of the interstate road system and the maintenance of Pennsylvania&apos;s already expanded highway system form the essentials for this expanding market.

Jan 1, 1968

Canada is a major producer of chrysotile asbestos. In fact, Canada accounts for approximately one third of the world chrysotile asbestos production. Deposits are mined and the fiber processed in Québec, in British Columbia on the West Coast and in Newfoundland in the Atlantic region. Foremost among the Canadian provinces is obviously Québec. Some 85% of Canadian deliveries come from mines located in the Eastern Townships, a region which lies along the southshore of the St. Lawrence River, between Montreal and Québec City. At the heart of this vast territory, five (5) mining towns make up what is called the Québec asbestos region. Total capacity of the five (5) mining producers of Québec is about 1 366 000 tonnes.

Jan 1, 1981

By George Munro

New Zealand is a small, almost pristinely pure country environmentally speaking. It is blessed with an abundance of clear waterways, lush green vegetation and fresh clean air. It is a country in which agriculture and forestry predominate, and mining developments have to be introduced prepared to answer in considerable detail the question "How will this proposal affect the New Zealand environment as we know it today". Those who make the legislation have the difficult problem of establishing standards at a level which will maintain as far as possible the status quo without unduly inhibiting the developments currently approaching the starting line. We have been fortunate in some sense in that since the demise of the early gold rush days by the 1920's, little mineralisation of a complex nature has been uncovered in New Zealand. Coal fields have been developed in the central North Island, and on the West Coast and Southland regions of the South Island. A ban on large scale open cast mines in the Coromandel area has restricted mining in that highly prospective area, although three large gold prospects have got underway elsewhere in the last three years. There is no other ore processing being undertaken at present. Some recent proposals involving lead, gold and silver in complex arseno­ sulphides have failed to get the necessary approvals and have been discarded. Our ore processing problems are therefore straightforward ones, and confine themselves to acid drainage, mercury handling and disposal, and cyanide.

Jan 1, 1991

By George W. Toth

In a recently completed research project for the U.S. Bureau of Mines - Twin Cities Research Center, a computerized costing procedure for uranium in situ leach mining was developed by the NUS Corporation. This costing procedure, termed a cost model, employs a process engineering approach for estimating total project costs as well as equipment and manpower requirements for uranium in situ leaching operations in either Texas or Wyoming. 80th capital and operating costs are generated by the model along with the overall production cost/pound U3O8 subject to a known rate of return. Conversely, rate of return on equity can be solved for, subject to a given price of yellowcake. During the course of the research effort, this cost model was applied 50 typical site conditions in Texas and Wyoming. Sensitivity rests were conducted for numerous key parameters to determine the cost influence attributable to incremental changes In parameter values. The results of these sensitivity tests along with a description of the in situ leaching cost model have been documented as Bureau of Mines, Mineral Research Contract Report No. J019912, "Cost and Sensitivities Analysis for Uranium In Situ Leach Mining," dated March 1981.

Jan 1, 1981

Mining employment, gross output, local economic contributions and productivity are typical economic indicators. However, these economic indicators play a much bigger role in the overall capacity of the industry to be heard in decision-making on a national scale. Total mining employment in the USA has decreased significantly in the last 20 years. Gross output from most of the mining sectors has also declined, except in the case of construction aggregate. However, significant gains have been made in productivity. This paper explores these statistics and comments on their overall impact on academic institutions and political decision-making.

Jan 1, 2003