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By Yuanhong Qi, KUN CUI, Tao Fu, XUNFU WANG, Yingyi Zhang, Jie Wang, Junmao Qie

Indonesia is the world’s largest supplier of nickel ore, with its nickel laterite resources mainly distributed in the Moluccas and Sulawesi regions. However, there is scant research on the mineralogical characteristics of nickel laterite deposited in southeast Sulawesi, Indonesia. This study aims to investigate the mineral phase structure, chemical analysis, thermal properties and element distribution characteristics of the middle and lower part of the rotten rock zone located in the southeast Sulawesi ophiolite belt.

By Clarence A. Johnson

The discovery of the Prudhoe Bay field temporarily reduced interest in the development of coal conversion processes, but interest is being re¬newed by the current energy crisis. According to M.A. Wright, Chairman of the Board of Humble Oil and Refining Company(l), the reserve in the Prudhoe Bay bield has been confirmed to be about 10 billion barrels. At first glance this appears to be an extremely large reserve which will eliminate supply problems for the United States for some time. This feeling of security is lost when one realizes that by 1980 the world will consume the reserves of a Prudhoe Bay or a Libya, or Venezuela in less than a year, based on the recent predictions of U.S. and world reserves made by Eastman-Dillon, Union Securities Company(2). Recent forecasts of U.S. demand and source of supply made by Kenneth E. Hill of Eastman-Dillon are shown in Figure 1. This forecast shows a decline in domestic supplies (excluding Alaska) after 1973, with the total domestic supply leveling off in 1975 at about 13 million barrels per day. Since the predicted demand increases from about 14 million barrels per day in 1970 to about 20 million barrels per day in 1980, about 35% of domestic consumption must come from imports or non-conventional sources by 1980. More imminent is the shortage of low sulfur fuel oil which has been created by the new, tough air pollution regulations that are basically legis¬lating eastern coals out of the market. As an alternate to importing large quantities of low sulfur fuel oil or importing and desulfurizing regular fuel oil, one of two domestic solutions is possible: stack gas clean-up or solids fuel pretreatment. Stack gas clean-up may be the cheapest approach for old installations, but fuel pretreatment has real advantages for new installations. Coal pretreatment at the mine could eliminate all solids fuel handling

Jan 1, 1972

By Albert F. Duzy

Recently there have been some problems associated with hot coal in shipments from the USA to overseas markets. This paper will serve several functions. First, a brief review is presented, together with a selective bibliography. Second, a thorough discussion of coal oxidation is covered. Third, potential effects of storage are presented and, lastly, methods are suggested for the safe storage and bulk transfer of coal. The scope includes coal storage for power plants.

Jan 1, 1983

By P. G. Tzeferis

Factory beet molasses media were used as cheap sources of sucrose for microbial leaching of Greek nickeliferrous laterites using strains of Penicillium and Aspergillus sp. Nickel recoveries of up to 62% and cobalt recoveries of up to 50% were obtained by leaching in a two-phase system in which bioacids were produced by fungal metabolism in molasses ferrocyanide pretreated media. The addition of potassium ferrocyanide to the molasses substrates prior to leaching was found to have a beneficial effect by increasing the level of citric acid bioproduction, thus improving the leaching efficiency of the fermentation liquid. The metals known to interfere with citric acid production (i.e., Fe, Cu, Ca and Mn) were those most efficiently precipitated. Considering the much lower commercial price of molasses in the industrial market compared to sucrose and glucose carbohydrate media, molasses could prove to be a promising alternative, despite the cost of the required pretreatment.

Jan 1, 1995

By Erik Westman, Benjamin Mirabile

"Ongoing research is being conducted to evaluate secondary support performance in longwall ventilation entries. In a three-entry longwall gateroad, secondary supports are applied in the #2 entry to maintain a functional airway for the entirety of second panel mining. This airway represents a pathway for contaminated mine air to travel from the longwall tailgate to the mine bleeder system. The ground response curve concept may be used as a design basis for selection of appropriate secondary support in these ventilation entries. Two types of secondary supports are monitored for load and convergence in this project. These monitored supports are pumpable crib supports and interlocking wood crib supports. To evaluate the effect of support density, two installation patterns are monitored for each support type. Both a single-row, protected airway pattern and double-row, full entry support pattern are monitored for each support type. Load and displacement data is collected for all support patterns as second panel mining retreats past instrumentation sites. Data is collected for approximately 200-feet inby the second panel face or as long as safely possible. Load and convergence data collected will be used to calibrate numerical models that will simulate ground response curves for the #2 entry inby the second panel face.INTRODUCTIONWhen a bleeder ventilation system is used, the #2 entry of a three-entry longwall gateroad system is designed to function as a pathway for contaminated air from a longwall face to the bleeder system during second panel mining. The #2 entry is subject to substantial ground movement and loading during its function as an air course because it is a single entry between two longwall gobs. Secondary support is regularly applied in this entry to maintain air course functionality during second panel mining.Research on performance and design of secondary supports has been conducted extensively over the last 30 years (Barczak and Gearhart, 1993; Barczak and Gearhart, 1994; Mucho, Barczak, and Dolinar, 1999). This research has focused heavily on the application of secondary support in longwall tailgate, with little research on the application of secondary support in bleeders or other ventilation entries (Mirabile and Westman, 2018). Secondary supports in #2 entry are likely to experience similar loading and ground movement as those applied in the tailgate entry. However, the designed lifespan of the mine entry and the definition of acceptable ground conditions differs from mine entries where more extensive research has been conducted."

Jan 1, 2019

By V. N. Kolesnikov

The gold-silver deposits of the northern Primorye region are located in the eastern part of the East Sikhote-Alin volcanic belt, where the belt overlaps the Kema island-arc terrain of the Aptian-Albian age. There have been four deposits and numerous mineralization points found in the NE-trending Kema metallogenic belt that is about 1000 km long and 100 km wide. The known mineralization is of epithermal type, controlled by faults, and concentrated in quartz, quartz-fluorite-adularia, and, less commonly, sulfide-quartz vein systems hosted by the Upper Cretaceous-Lower Tertiary volcanic rocks. The vein systems extend for hundreds meters along strike, varying from tens centimeters to 50-60 meters in width. They are surrounded by wide zones of low-temperature hydrothermal alteration containing some gold-silver mineralization for which the commercial value was not studied during the early exploration. The ore bodies contain from 1 to 50-80 ppm of Au and from 1 to 1000 ppm of Ag. Gold is native, associated with quartz, and represented by particles from tens of microns to 1 mm in size. Silver occurs in native form as a constituent of argentite, pyrargyrite, stephanite, and other sulfosalts. The test work carried out for three vein systems 20 years ago showed that gold might be easily and almost completely recovered from the ore by cyanide treatment. The paper describes the geology and mineralogy of the deposits, Salut and Primorskoye, that are the most studied properties of the Kema belt. It also presents the data available on disseminated gold-silver mineralization in stockworks, altered explosive breccias, and wide zones of low-temperature hydrothermal alteration. This mineralization should be explored for possible exploitation as large open-pit, heap-leach deposits.

Jan 1, 1998

By J. M. Marek

The determination of the proper cutoff grade for an open pit metal mine is based on economic criteria and the operating philosophy of the mining company. Previous papers have dealt with the balance of a fixed mine production capacity versus economic return. Mine production capacity is often controlled by the amount of mining equipment and the working area in the pit. A complete cutoff grade strategy is a balance of economic return of mining higher grade material versus the capital costs of additional production capacity and the operating cost of moving the waste and low grade material to assure proper ore release. An approach to the problem is presented which is based in part on work by previous authors and provides guidelines to proper cutoff grade strategy encompassing the time value of money and variable commodity prices.

Jan 1, 1985

By J. Herhold, S. Plaum

"Increasing worldwide energy demands, coupled with desires for cleaner energy, have led to greater research of renewable energies. Strongly weather-dependent energy sources, e.g. solar and wind energy, are unable to provide a constant control energy to withstand the fluctuation of the extensive power systems during peak hours. The pump storage plant Nant de Drance in Switzerland will not only have the capacity of a nuclear power plant, producing 900 MW, but will also combine the environmental aspect and the demand for controlled energy. Nant de Drance is one of the pioneer projects for upcoming energy challenges and serves as a model for future pump storage plants. This paper focuses on the planning process and the project execution of interdisciplinary large-scale projects such as Nant de Drance, including project related data handling, communication systems and project handling skills. Furthermore, the paper discusses mining excavation in the context of large scale projects and their regional environmental challenges, e.g. high alpine rock mass on the site of Nant de Drance. PROJECT BACKGROUND Project Overview Nant de Drance is a 900 MW pump storage plant located in the Swiss Alps. To provide such a high energy storage, six turbines (reversible Francis type), each with a capacity of 150 MW, were installed. Due to the efficiency factor of 80% the pump storage plant is able to provide an energy production of 2500 GWh per annum. Construction of the pump storage plant, which has been selected as “Major Tunneling Project of the Year” in 2014 by NCE and ITA-AITES, will be completed over 10 years. Therefore, the project has been divided in six major phases outlined below: - Launch: 2008 - Access Gallery: 2010 – 2012 - Excavation KMA, KTR: 2011 – 2014 - Concreting KMA, KTR: 2014 – 2016 - Installation of HEM equipment: 2014 – 2018 - Tests & entry into service: 2017 – 2018 Figure 1 outlines the single process phases of the project. For the construction of the shafts, galleries and caverns, 1.7 million m³ of metamorphic rock with sedimentary origin (mica schist & paragneiss of the massif „Aiguilles Rouges“) were excavated. A tunnel network with a total length of 15 km was created. The machine cavern measures 194 m long, 32 m wide and 52 m tall."

Jan 1, 2016

By T. Tamagawa, I. Iwasaki, N. X. Fu, M. Kobayashi

A three-stage fluidizing-bed process consisting of chlorination, selective oxidation and sulfur chloride conversion was tested for processing chalcopyrite concentrate. It was found that the use of excess oxygen was essential for the stable operation of the oxidation reactor. The excess-oxygen gas inevitably causes the oxidation of the sulfide concentrate in the chlorination and sulfur chloride conversion reactors. A new flowsheet is proposed to separate the chlorination and selective oxidation steps with separate flow paths of the fluidizing gases, thereby, preventing the passage of excess-oxygen gas in the chlorination and sulfur chloride conversion reactors. The feasibility of the proposed flowsheet was demonstrated in a laboratoryscale fiuidizing bed setup.

Jan 1, 2002

By B. A. Waite

The new OSH regulations concerning ground ward monitoring of underground coal mines has been the source of many concerns for the mining industry. Because the regulations were initially written at the federal level but are being administered at the state level, considerable confusion exists within the industry as to what is actually required. Based on the preparation and submission of over 30 monitoring plans for existing deep mines in Pennsylvania, West Virginia, and Ohio, we now have a very good feel for the detail the monitoring plans, as well as the costs to im plement the plans. We do not, however, feel confident in our evaluations of the long-term impact the ground water monitoring regulations may have on the industry.

Jan 1, 1980

By James L. McGregor

St. Joseph Lead Company has been paying incentive bonuses for well over 40 years. In 1958 almost half of St. Joe's 1,860 employees in Southeast Missouri received some form of incentive bonus in addition to their guaranteed wages. There are very few payroll jobs in St. Joe s Southeast Missouri organization that lend themselves to a reasonably good measurement of production or quality, or both, where an incentive bonus is not paid. The term "Incentive Bonus" is used to differentiate betwen bonuses that are based on quantity or quality of work, and those that are merely additional pay of a standard amount per hour or day because of an employee being temporarily assigned to some unusual task, An employee temporarily assigned to a job where the working conditions make the job performance unusually difficult or where a special skill is used is often given a bonus of some standard amount per hour or shift in addition to his usual rate. This is merely a convenient way of paying something extra without disturbing the normal rate structure. Actually, it is differential pay similar to that almost universally paid for evening and night shift work. Bonuses of that type are not being considered in this paper. The basic reason or theory for paying incentive bonuses 9s to get improved production at lower cost, Unfortunately, it is often difficult, if not impossible, to find a yardstick by which it can be definitely proved that a particular bonus plan is accomplishing its purpose, It becomes, then, a matter of judgment on the part of management personnel as to the value of the bonus plan. The fact that St. Joe Lead Company has continued to pay bonuses for over 40 yews and has increased the number of bonus schedules used attests to a definite belief that they are beneficial to the company's successful operations.

Jan 1, 1960

By P. McGrath

From the mid-1980s through 1997, Echo Bay Alaska evaluated reopening the historic Alaska-Juneau (AJ) gold mine. Their original proposed project underwent numerous modifications in order to minimize the potential for significant environmental impacts. One of the major modifications involved changing .the tailings disposal method from a conventional tailings impoundment to submarine tailings disposal (STD). In 1995, the U.S. EPA began work on a Supplemental Environmental Impact Statement (SEIS) to assess the impacts of the STD proposal. Key features of the STD impact assessment included fate and transport modeling to determine the extent of tailings deposition and the use of ecological risk assessment to predict marine impacts during deposition and ecosystem recovery following STD. A key feature of the SEIS regulatory process included a rulemaking proposed by EPA to exempt the AJ tailings from effluent regulations. Critical to success in moving the project forward was early development of an interactive working relationship with other regulatory agencies and the public.

Jan 1, 1998

By J. E. Oberholtzer, M. G. Fernald

INTRODUCTION Approximately six years ago the U.S. Bureau of Mines (USBM) developed a data acquisition system (DAS) specifically designed for measuring radon levels and other environmental parameters during studies of means to control radiation hazards in underground uranium mines. The DAS system records data in machine readable form using a paper tape punch, which represented the state-of-the-art at that time for a moderate cost output device. However, the use of paper tape as a recording medium for field studies is somewhat unwieldy. Reducing the raw data required either that the tape be shipped to a computer center equipped with a high-speed paper tape reader or that the tape be transmitted at low speed over the telephone lines to a remote computer. Transmitting, at ten characters per second, the data from a 10-channel DAS taking Four readings per hour would require about 30 minutes For each 24-hour day's data. Telephone lines from remote mine sites are often of marginal quality and data errors can be introduced during transmission. Paper tape punches are also prone to occasional punching errors. Both problems make it necessary to carefully check for and correct data errors, a process which is possible because each DAS produces an independent printed data record, but the error checking and correction process can be quite laborious. Aware of recent advances in microcomputer technology which have brought the price of a personal computer down to about the cost of a paper tape punch 5-10 years ago, the Bureau decided to explore the feasibility of using a low-cost personal computer in the field to process DAS data in real time. On behalf of the Bureau, Arthur D. Little, Inc., developed a simple interface circuit which permits an Apple II computer to accept data from one or two DAS units as it is being transmitted to the paper tape punches. Computer software converts each measurement to appropriate engineering units, e.g., radon concentration, Working Levels, air velocity, temperature, or barometric pressure. The computer also calculates 1-hour and 8-hour running averages of all converted data and prints those results as soon as they are obtained on a line printer located at the test site for immediate inspection. After development, the system was used continuously and successfully for a 5-month period at a Utah uranium mine. DAS DESIGN AND MODIFICATION Each of the two USBM data acquisition systems used in this work consists of two separate modules. A multiplexer module located below ground near the measurement transducers acquires signals from each of nine tranducers. Six input channels were devoted to measurements of radon or Working Level. The outputs of those transducers, photomultiplier tubes or G-M tubes, respectively, are digital pulse trains which are accepted directly by the mutliplexer. Three channels were used for environmental parameters--air velocity, temperature, and/or barometric pressure. Each of the environmental tranducers is fitted with dedicated linearizing and voltage-to-frequency conversion circuitry so that the outputs to the multiplexer are also pulse trains having frequencies of one tenth of the value of the measured parameter expressed in the appropriate engineering units. A 100-Hz reference signal was input into the tenth channel for use in monitoring system integrity and performance. All ten pulse trains are then timeseries multiplexed into a signal line for transmission to the above-ground data acquisition module. Above ground, the composite signal is de-multiplexed into ten separate lines, each of which is connected to a digital counter which converts the pulse train to a numerical value. The acquisition of each set of readings is initiated by an adjustable "scan cycle comparator" timer. The acquisition process proceeds in three phases. First, radon and Working Level channels are counted for an extended period of time, typically 5-10 minutes depending on activity, because of the low pulse rates involved. Then the other four channels are counted for ten seconds, and finally, all ten readings, along with the Julian day and time of day are output serially onto paper tape and printed on a strip printer. When the scan cycle comparator reaches its preset time (15-minute cycle times were used in this work), it resets itself, initiates another readout cycle, and begins timing again. The only modification made to the data acquisition systems used in this work was to disconnect the scan cycle comparator in one unit, which became the "slave" and bring in the scan cycle comparator signal from the other unit, the "master", to initiate data acquisition cycles in the slave. Synchronizing the two data acquisitions in this fashion and using two slightly different radon counting times insured that the two systems never attempted to output data to the Apple II at the same time. THE APPLE II COMPUTER The Apple II computer used in this work was equipped with 48 KBytes of semiconductor random access memory (RAM), two floppy diskette drives, a Centronics Model 730 impact matrix printer and a modulator for driving an ordinary color television as a video display device. A single California Computer Systems Model 7720A dual 8-bit bidirectional parallel input/output (I/O) card was installed in the Apple to accept the digital data from both data acquisition systems. This card is

Jan 1, 1981

By J. A. Madonna

Universities and colleges in three countries, Australia, Canada and the United States, recognized the need to establish and/or reorganize geoscience programs at the vocational and two-year technical levels. To accomplish this goal, a cooperative study with industry in one state or province from each country was initiated. These include 1) Tasmania, Australia, 2) British Columbia, Canada and 3) Alaska, United States. Over one hundred mineral industry organizations cooperated in the study by providing information regarding their specific training needs for support personnel. The data gathered has been used to identify training areas for semi-skilled, skilled and technical personnel in geochemical mineral exploration, including, but not limited to, geological skills, geochemical skills, environmental skills and computer skills. With the areas of major educational need defined for geochemical exploration, an educational field skills model has been developed for the three levels of training. The depth of each level of education and the training objectives for the work force at each level will be discussed.

Jan 1, 1993

By Kanaan Hanna

A joint research program between the U.S. Department of the Interior's Bureau of Mines and Cyprus-Yampa Valley Coal Company is being conducted at the Foidel Creek Mine, Oak Creek, Colorado. This program goal is to study the effects of state-of-the-art, high-speed, automated longwall mining on health and safety, and primarily, ground stability under various geological conditions. The Bureau installed an automated data monitoring system, known as the Ground Control Management System (GCMS), to monitor in real-time the effect of rapid mining on pillar and face loading, stress redistribution in and around the longwall panel, and caving characteristics of the roof. The Bureau's GCMS, combined with the company's existing monitoring systems, which include environmental monitoring, a computer programmable conveyor belt system, and gamma ray roof control thickness indicators, has been effectively used to improve safety at the face, increase productivity, and reduce production costs.

Jan 1, 1991

By Charles E. Dandois

New is a relative term, and, when used with reference to a concept as old as shaft kilns can be applied to a number of designs. In this case the design that is the subject of this paper, is known as the ring or annular shaft kiln as developed by Mr. Karl Beckenbach of West Germany. The first&apos; operating unit was rated 185 tons per day and was installed in 1962. Today, there are approximately 84 units in operation in Western Europe and Japan. Twenty-one additional units are in the process of erection or on order. Developed sizes range from approximately 100 to 330 tons per day. Units of over 500 tons are in the design stage, however, the largest units presently operating are rated 330 tons per day, <the first: of this size having been installed in 1966. "Figure" 1 is an elevation view of the unit. It is a single vertical cylinder to which are attached the required service platforms, combustion chambers, injectors and distribution piping. Auxiliaries such as recuperator, exhaust fan and dust collector are mounted on the appropriate service platform. The charging pan, feed conveyor, etc. are mounted at the kiln top. At the bottom of the kiln is the silo with a vibrator type discharger, and mounted separately is the required blower for injector air and fan for internal cooling.

Jan 1, 1973

By D. Erik Spiller

Mineral processing technologies are being used in the environmental arena for remediation and secondary recovery. Comminution and/or scrubbing for liberation, coupled with separation of the liberated particles, is known as soil washing. Other metallurgical unit operations have found application in remediation and recycling: size classification, gravity concentration, flotation, magnetic and electrostatic separation, eddy current separation, and liquid/solid separation. This paper presents specific examples of the use of these technologies to clean up contaminated soils and plant residues, and to recycle valuable materials from waste streams.

Jan 1, 1993

By H. J. Sandri

In the spring of 1991, Western Aggregates, Inc. began operating the newest expanded shale lightweight aggregate operation in North America. The operation is located in Jefferson County, Colorado, just south of Boulder, at the sight of the former Ideal Basic Industries ("Idealite") lightweight aggregate plant, which was decommissioned in 1975. The "new" facility has been built to principally serve the Denver and Front Range markets, as well as ship products into other locations in Colorado, Wyoming, New Mexico, Kansas and Nebraska. Western Aggregates is a wholly-owned subsidiary of Inco U.S., a subsidiary of Inco Limited of Toronto, Canada. Inco Limited is the free world&apos;s largest producer of nickel and is a leading producer of copper, cobalt, gold, silver, and platinum group metals, high nickel and super alloys, and specialized engineered products. Inco is constantly seeking new mining related investments that leverage off its mining and processing skills and that meet corporate fmancial objectives. Construction materials are an area presently being pursued by Inco. The basic &apos;building blocks&apos; of society, from a construction perspective, are sand and gravel, stone, and aggregates. To the vast majority of people these are natural products that are mined, quarried or dredged, and other than washing, screening and crushing, are generally used in their primary form. While these materials vary from quartzite river rock, to calcified limestone, to hard basalt, they are generally classified as "heavy" aggregates. There are, however, other types of aggregates that do not fall under the "heavy" classification, but are used in general construction activities just the same.

Jan 1, 1992

By R. B. Tippin

The material balance computer program (MAT-BAL) developed at the Minerals Resource Research Center of the University of Minnesota, has been used in conjunction with routine process profile samples taken in the potash compaction plant at Great Salt Lake Minerals and Chemicals Corporation, Ogden, Utah. In this manner, a uniform data base is being established for the process, and selected key indicators are used for decisions in plant operation and maintenance. With present emphasis on improving product quality and increasing production rates, the standard data base system provides a means of measuring results from test programs to optimize the circuit. The development and application of this process control method is discussed. The compaction plant computer-assisted data base has been in existence for only two years, but it has made significant contributions to the knowledge of the process and continues to assist in monitoring the plant performance. It is anticipated that the material balance program will be adapted to the GSL flotation plant in 1979, and to other circuits in the potassium sulfate chemical plant.

Jan 1, 1979

By J. Hanna, J. Jung

Researchers at The University of Alabama have recently developed a two-step method for the treatment of phosphorus sludge. The process includes the bulk removal of phosphorus by physical separation techniques followed by the remediation of the residual P4 in the sludge using a novel, wet, air-oxidation technique known as "HSAD." Tests made on electric furnace, phosphorus sludge samples have demonstrated that an essentially complete and fast removal of the contained P4 can be achieved by the HSAD wet oxidation treatment. Further studies were made to determine the applicability of the two-step process to sludges of different origins, pretreatments, storage conditions and P4 contents. The present work discusses the mechanisms and factors controlling the HSAD, wet, air-oxidation remediation approach.

Jan 1, 1993