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The present study refers to passive systems for the treatment of acidic liquid effluents emanating from mixed-sulphide mines by means of an-aerobic compost wetlands. An effort was made for the thermodynamic study of the chemical systems that are involved in the reactions during the simulation of this specific system using laboratory columns and a pilot scale application. The substrate used was a mixture of cow manure, a high alkalinity organic substrate and chestnut woodchips, while the synthetic solutions prepared for the laboratory experiments contained the three basic metal contaminants i.e. Fe, Zn and Mn. The precipitation mechanism of the contained metals and the form in which these are precipitated was therefore investigated by constructing the equilibrium phase diagrams (Eh-pH diagrams) of the Me-S-C-H2O systems. Based on the experimental results from laboratory and pilot scale tests the stability conditions of the chemical species taking part in the aqueous solutions were also determined and verified with the thermodynamic data available. The thermodynamic analysis of the system was performed for ambient temperature, which is the prevailing temperature on field constructed compost wetlands. Results were further validated with the results obtained by the application of a five step sequential extraction procedure in the remaining substrate in order to determine the form in which the metals were precipitated.

Jan 1, 2006

By G. A. Johnson

Basic management principles will be discussed (as they apply to minerals education efforts), especially in light of the changing nature of volunteerism in today’s society. Also, the “minerals education tree” will be presented, along with public opinion / public policy realities.

Jan 1, 2001

By Walter J. Pachucki

Mining equipment maintenance costs account for a major portion of a mine’s total operating expense. A reduction of maintenance costs while providing required equipment availability translates directly into increased profit for a mine. Therefore, having in place a successful maintenance program can be management’s most direct route to increased profits. One key element of a successful maintenance program is a practical and effective recordkeeping and information system. In recent years, many mining operations have invested in the development or purchase of computerized maintenance information systems. Computerized maintenance information systems can serve as a valuable tool in managing mining-equipment maintenance. They can also be a costly, frustrating waste of time. Why are some systems successful at one operation but a failure at others? Should all mines use computerized maintenance information systems? How does management decide what maintenance software is best for their operation? In an effort to to answer these questions and to better understand what is required to make a mining maintenance information system successful, a study was recently conducted on maintenance information systems used in the mining industry.

Jan 1, 1991

By A. Supomo, A. Partanen, M. Mular

Although many SAG operators may agree that on-line measurement of SAG feed-size is an attractive notion, applying this information in a control strategy that recovers the investment, engineering time, and maintenance is not necessarily straightforward. The P. T. Freeport Split-Online system was justified based on the assumption that SAG feed-size could be used in a feed-forward control strategy either at the regulatory or expert system control level. Something like “as the feed size changes adjust the throughput to avoid under or overloading the mill” was envisioned. However, following installation and calibration, Cluster Analysis showed that such an approach would not be successful. However, the sensor has been successfully integrated into Freeport’s grinding control strategy other ways. It provides an input to the Kalman filter parameter estimator used in a model-based control strategy that optimizes throughput and grind. The Split sensor also provides a characteristic feed size parameter for use in an on-line work index estimator. This paper describes the calibration and installation of the Split SAG feed-size analyzer, and reviews the evolution of its use in the Freeport C3 grinding circuit control strategy.

Jan 1, 2001

By Larry D. Hartzog

For detailed information you are referred to "Heap Leach Solution Application at Rochester" by S. N. Dixon and A. L. Wilder which will be presented at the SME Meeting in Phoenix, January 1988.

Jan 1, 1998

By K. Oraee

Rate of penetration of Tunnel Boring Machines (TBM) has a significant role in the planning, measurement of productivity and performance of any tunneling project. In this paper, the application of Adaptive Neuro Fuzzy Inference System (ANFIS) in prediction of TBM penetration rate is evaluated. For this purpose, a database including Rock Quality Designation (RQD), Uni-axial Compressive Strength (UCS) of the rock, the Distance between Planes of Weakness (DPW) in the rock mass, and empirical data regarding rate of penetration of TBM from several tunneling projects are collected. The Rate of Penetration is then estimated by using ANFIS. These results are then compared with measured TBM penetration rates (actual data). It is concluded that ANFIS can be applied successfully for such purpose and result in high accuracy for prediction for the rate of penetration of TBM. The method provided in this paper can assist the mining engineer to estimate the performance of tunneling accurately.

Jan 1, 2012

By Haydn H. Murray

The term clay is somewhat ambiguous unless specifically defined, because it is used in three ways: 1) as a diverse group of fine-grained minerals, 2) as a rock term, and 3) as a particle size term. As a rock term, clay is difficult to define because of the wide variety of materials that comprise it; therefore, the definition must be general. Clay is a natural, earthy, fine grained material comprised largely of a group of crystalline minerals known as the clay minerals. These minerals are hydrous silicates comprised mainly of silica, alumina, and water. Several of these minerals also contain appreciable quantities of iron, alkalies, and alkaline earths. Many definitions state that a clay is plastic when wet. Most clay materials do have this property, but some clays are not plastic, e.g., halloysite and flint clay. As a particle size term, clay is used for the category that includes the smallest particles. The maximum size particles in the clay size grade are defined differently on various grade scales. Soil investigators and mineralogists generally use 2 pm. as the maximum size, whereas the widely used scale by Wentworth (1922) defines clay as material finer than approximately 4 pm. Some authorities find it convenient to use the term clay for any fine-grained, natural, earthy, argillaceous material (Grim, 1968). When used this way, the term includes clay, shale, or argillite, and some argillaceous soils. Even though no standard definition of the term clay is accepted by geologists, agronomists, engineers, and others, the term is generally understood by those who use it. Clay is an abundant natural raw material, and it has an amazing variety of uses and properties which will be discussed in this chapter. Clays rank among the leading industrial minerals in both tonnages produced and total value. Their importance is indicated in Table 1, which lists the 1988, 1989, and 1990 productions according to the US Bureau of Mines (Ampian, 1992). As industrial minerals, clays are a complex group that consists of several mineral commodities, each having somewhat different mineralogy, geologic occurrence, technology, and uses. In this section these commodities are organized as follows: 1) bentonite, 2) common clay, 3) hormites, and 4) kaolin. Fuller's earth is discussed in both the bentonite and hormite chapters. Fuller's earth is a term based on use, and both bentonites and hormites are sold as fuller's earth. The overlapping is particularly evident where both bentonite and non-bentonite fuller's earth are used for the same purposes or products, such as in drilling mud, bleaching or clarifying fats and oils, and carriers for insecticides and fertilizers. Kaolin, ball clay, halloysite, and refractory clays are grouped together because they consist mainly of minerals of the kaolin group. Common clay is a grouping of several fine-grained materials, including shale, sometimes referred to as miscellaneous clay. The scientific and technological publications pertaining to clays

Jan 1, 1994

By Ross A. Scarano

It wasn't until late 1976 that the U. S. Nuclear Regulatory Commission (NRC) set about to address the uranium tailings issue in earnest. It was decided that a generic environmental impact statement related to uranium milling operations would be prepared to support formal tailings regulation. We recognized, however, that this was a task that would take many years to complete and we could not take a "business as usual" approach to tailings management in the interim; the issue was too sensitive. To facilitate licensing during the interim period, the NRC developed guidelines in May 1977, for the industry in the form of the following performance objectives for tailings management: Siting and Design 1. Locate the tailings isolation area remote from people such that population exposures would be reduced to the maximum extent reasonably achievable. 2. Locate the tailings isolation area such that disruption and dispersion by natural forces is eliminated or reduced to the maximum extent reasonably achievable. 3. Design the isolation area such that seepage of toxic materials into the groundwater system would be eliminated or reduced to the maximum extent reasonably achievable. During Operations 4. Eliminate the blowing of tailings to unrestricted areas during normal operating conditions. Post Reclamation 5. Reduce direct gamma radiation from the impoundment area to essentially background. 6. Reduce the radon emanation rate from the impoundment area to about twice the emanation rate in the surrounding environs. 7. Eliminate the need for an ongoing monitoring and maintenance program following successful reclamation plan. 8. Provide surety arrangements to assure that sufficient funds are available to complete the full reclamation plan.

Jan 1, 1980

By Phillip O. Tyree, R. A. Metz, Joseph W. Mussey

Bio-epigenetic sulphur deposits occur in Pecos, Reeves and Culberson counties of far West Texas. Sulfate reducing bacteria, utilizing hydrocarbons as energy, transformed gypsum into replacement limestone and hydrogen sulfide. Hydrogen sulfide, retained in the pores of the replacement limestone, was subsequently oxidized by highly oxygenated groundwaters, and native sulphur precipitated. West Texas sulphur was first recognized at surface exposures by William P. Blake, a geologist attached to the Captain Pope Military/ Scientific Expedition of 1854. Attempts were made in the early 1900's to mine these sulphur vent exposures by a retort method, but the ventures met with little success. In 1967, Duval discovered a large sulphur deposit near some of the old sulphur works in Culberson County. Duval also expanded reserves in a small sulphur deposit in Pecos County. The Frasch process, developed for producing sulphur from Gulf Coast salt domes, proved successful in West Texas type sulphur deposits also. However, modifications of the process were necessary to provide economical and efficient sulphur recovery from the varied ore occurrences. West Texas conditions and logistics require the ultimate in productivity to be competitive in the domestic and foreign sulphur markets. Several companies, in addition to Duval, are producing or have produced sulphur in West Texas. As of June 1, 1984, a total of 29.87 million mt (29.4 million long tons) of sulphur had been produced west of the Pecos River. Duval corporation has produced more than 88 percent of that total.

Jan 1, 1992

By Prof. Dr. T. R. Boulos

The Egyptian marine phosphorite of Sebaiya West, the Nile Valley, consisting of both non-oxidized hard siliceous and oxidized leached friable ore types, is subjected to a roughing-cleaning silica flotation circuit for production of wet-process phosphoric acid concentrate. Operating at its maximum capacity of 268 t/hr, the following were the main problems encountered during the early stages of running the plant: 1. The tremendous amount of slimes generated by scrubbing the crushed ore causing turbidity in the plant thickener after a short time of operation, regardless of the added flocculant. 2. Rod mill choking leading to inefficient performance of all other equipment and poor flotation results. 3. The drastic increase in imported oleic acid price. Pulp density and slurry flowrate measurements at different points of the plant as well as ore microscopy, size distribution analysis, chemical analysis and x-ray diffraction analysis of representative ore samples coupled with Work Index measurements of feed samples showed that the wide variation in the ore's hardness was responsible for such problems. Application of the locally produced non-edible rice bran oil as a substitute to imported oleic acid in flotation resulted in total saving of U.S.$2 million in 1990. The total unsaturated fatty acid content of the oil is high, ranging from 75.2 to 81.5 mole % of which the C18-unsaturated fatty acid content ranges from 72 to 79 mole %.

Jan 1, 1993

By E. W. Geist, W. J. Bronkala

PRINCIPLES OF MAGNETIC SEPARATION The application of magnetic separators relies on the different behavior of individual mineral particles under the influence of magnetic forces. When exposed to a magnetic field, all materials are affected in some way. According to whether materials are attracted or repelled by the magnetic field, they are designated paramagnetic or diamagnetic, respectively. Paramagnetic materials are attracted along lines of magnetic force from points of lower magnetic field intensity to points of higher magnetic field intensity. The very strong response of some materials to a magnetic field is sometimes designated ferromagnetic and the particles attracted frequently retain magnetic properties after the applied magnetic field is removed. Diamagnetic materials are repelled along the lines of magnetic force from points of high magnetic intensity to points of lower field intensity. Only limited commercial use of diamagnetic effects has been made. For practical applications, the paramagnetic groupings are: 1. Strongly magnetic (ferromagnetic) 2. Magnetic 3. Weakly Magnetic 4. Non-magnetic The limits of these groupings are not well defined and will vary in some mineral species. Only a few minerals are ferromagnetic (magnetite is an example) and arbitrarily some investigators have selected 10,000 gauss, or 1 Telsa, as the dividing line between low and high intensity magnetic fields. I. S. Wells has developed a table indicating the magnetic intensity required to separate a selected grouping of minerals which is shown in Table 1 on page 2. A similar table has been developed by Carpco Inc. of Jacksonville, Florida in conjunction with the use of its high tension separators. This table, Table 2 on page 3 shows other minerals grouped in the broader categories cited above. Magnetic separation methods are used either to separate valuable minerals from nonmagnetic waste or magnetic impurities or other valuable magnetic minerals from bulk nonmagnetic values. Magnetically susceptible mineral particles occur as either individually discrete particles,

Jan 1, 1986

By W. B. Beerbower

Resin bolting has enjoyed wide acceptance for coal mine roof support. Beginning in 1973, the first year of significant resin bolting in coal mines, we estimate that 2.5MM resin bolts were installed. This grew to 7MM resin bolts in 1974 and 13MM in 1975. Resin bolts are currently being used in over 300 coal mines throughout the major coal producing areas of the U.S. and barring major work stoppage we expect more than 17MM will be installed in 1976. Although not a cure-all, the number of unintentional roof falls occurring in many mines has been dramatically reduced as a result of converting to this "new" method of support. 1 The improved anchorage strength of resin bolts provides better roof support. (Slide #1) This anchorage strength provides a mechanism to resist changing roof stresses along the entire length of the fully grouted resin bolt, thereby assuring stabilization of rock strata over long periods of time. The ability to resist roof displacement is borne out by readings obtained from strain gauged bolts. These findings can be summarized as follows.2

Jan 1, 1977

By L. E. Allen, J. F. Abel, D. R. Morgan

The Waste Isolation Pilot Plant (WIPP) is a geologic repository for disposal of transuranic waste and is operated by the U.S. Department of Energy (DOE). The repository is located at a depth of 655 m in the Permian age salt beds of the Salado Formation, 40 km east of Carlsbad, NM. A key component in the design of the WIPP repository is the installation of concrete structures as panel seals in the intake and exhaust drifts after a panel has been filled with waste containers. The DOE has proposed several panel closure design modifications to the EPA. EPA approval of the changes is required since the details of the designs are specified in EPA’s final rule as a condition for WIPP certification. The Environmental Evaluation Group, in its role of providing technical oversight on the WIPP project, has evaluated the proposed modifications. An analysis of this evaluation is discussed.

Jan 1, 2003

By Gabriel de Almeida

INTRODUCTION The widespread use of desktop computers by an ever increasing number of people, both for personal and for business and government uses, has brought public attention to surprising stories about computer abuse. Before the advent of microcomputers in the information processing environment, hundreds of amazing misdeeds involving large computers had already been reported, most of them perpetrated by highly skilled professionals. The undreamed enlarging of microcomputer potential has steadily posed a major threat to complex mainframe computing systems, as joyful teenagers become familiar with the habit of hacking around someone else's large processing system, by means of makeshift phone communication networks, based on their intended homework for personal computers -- for the sheer fun of it. Now, the never ending capacity and speed improvement of commercially available micros has given rise to a brand new concern for society: the hazards of processing sensitive information in the powerful, but still unsafe microcomputer itself, whether or not linked to other micros or mainframe networks. This paper deals with some aspects of the problems and presents some practical hints as to enhance protection and minimize risks to sensitive and secretive information when processed on microcomputers. The physical considerations of computer security and pertinent safety precautions will not be discussed, because while essentially relevant to information protection, recommendations are well defined by processing resources suppliers and their importance is more widely recognized by users in general. Definitions and Classifications. The following definitions and classifications will be considered in this report: Information Assets: Any knowledge or information processing, storing or conveying device displayed in one's environment. It consists of two main categories: INFORMATION RESOURCES: End user's application data wherever recorded. PROCESSING RESOURCES: EDP skilled user's hardware, software, peripherals, magnetic media, communication devices, auxiliary equipment, supplies and related operational procedures. Information Protection: In a broad sense this is the set of necessary procedures to assure to the legitimate user the effective control of the operation and allow modifications of information assets, so that their physical or cognitive integrity be preserved or any unexpected loss minimized inspite of accidental occurrences or intentional actions. Classification Processes: Commonly two classification processes are used to define key terms in information protection: SENSITIVE CLASSIFICATION: Pre-defined standards for assessing the vulnerability to losses due to lack of proper processing continuity if information is destroyed, disclosed, secluded, or misused. SECRECY CLASSIFICATION: A spectrum of degrees as to the expectancy of holding exclusiveness of unique information whose destruction, disclosure, seclusion or misuse will cause a negative impact on the legitimate holder environment. Sensitive Information: Any knowledge whose destruction. disclosure. seclusion or misuse - - - implies losses to its legitimate holder. It may be classified as: VITAL INFORMATION: An essential knowledge whose lack of proper availability implies total loss or termination of p

Jan 1, 1987

By William D. Hanson

Celestine (celestite) (SrSO4), the primary ore mineral of strontium, is present in the DeQueen Limestone Member of the Trinity Group (Lower Cretaceous) in Sevier, Howard, and Pike Counties, southwest Arkansas. Two mappable celestine beds have been identified. One bed is commonly 3-5 in. thick, but ranges up to 18 in. in thickness; the other bed is generally 2-3 in. thick. The beds are concordant within the DeQueen Limestone and were formed by precipitation from periodically restricted sea water. Reports concerning celestine date back to 1929, when Hugh D. Miser and A. H. Purdue mapped the geology of the DeQueen and Caddo Gap quadrangles. A small amount of celestine was produced in the early 1940s in Howard County. During 1941, the J. W. Hintze Company collected 1,500 pounds of celestine for testing purposes. In 1942 and 1943,750 test holes were drilled by the Bennett-Clark Company in Howard County. Afterward, approximately 90 tons of celestine was open-pit mined and shipped to Texas for processing. Since then, no mining of celestine in Arkansas has taken place.

Jan 1, 1999

By M Ali, E Satriawan, M Napitupulu, A Munandar

The Deep Mill Level Zone (DMLZ) panel cave mine is one of three active caving mines at PT Freeport Indonesia’s Grasberg Underground Mining Complex. The DMLZ mine is located at a depth of approximately 1,500-1800 m below the surface, making it one of the world’s deepest panel cave mining operations. This depth results in both high in-situ and induced stress that acts on the hard and massive rock mass, triggering rockburst conditions. As a result of the bursting conditions, ground support and maintaining the support capacity are an essential part of operating the DMLZ mine in an efficient and safe manner.

Apr 26, 2022

By Lynne Chastain

The Eastern Shoshone and Northern Arapaho tribes of the Wind River Indian Reservation, Wyoming are interested in developing their industrial mineral resources. The U.S. Bureau of Indian Affairs (BIA), Division of Energy and Mineral Resources (DEMR) is assisting the tribes in evaluating the potential of their industrial mineral prospects for development. Gypsum occurs on both sides of the Owl Creek Mountains in the basal portion of the Jurassic Gypsum Springs Formation. The gypsum resources that are being evaluated crop out along the northern flank of the Owl Creek Mountains in the Sweetwater basin, a small topographic sub-basin of the Big Horn Basin. From October 1998, to April 1999, DEMR personnel mapped, sampled, and drilled the southcentral butte within the Sweetwater basin. Samples were analyzed for free and combined water, and major mineral oxides to determine gypsum purity. Gypsum purity averaged 93.6 percent for surface samples and 95.1 percent for drill core samples. The basal portion of the Gypsum Springs Formation is comprised of several beds of gypsum up to 9 feet (2.7 m) thick separated by 0.5 to 2.0 foot (0.15 to 0.61 m) thick lenses of siltstone and limestone. Overall gypsum in the formation ranges from 35 to 90 feet (11 to 27 m) in thickness. A resource of approximately 7 million short tons (st) (6.4 million metric tons [mt]) has been identified.

Jan 1, 2001

By Neville Slade, Doug Shumway, Dayan Anderson, Joe Siefke, Curtis James

The Mojave Desert is a particularly fragile ecosystem that faces several significant impacts. These include rapid housing development, overdrafted water supplies and loss of wildlife habitat — all a result of mining, industrial activity and urban sprawl. During the past three years, a diverse group of educators, natural resource managers and business leaders was assembled under the auspices of a local community college. This group’s goal was to provide unique natural resource education opportunities for the region.

Jan 1, 2005

By Thomas Schultheis, William Heron, Paul Watson, Colin Warren

This paper describes the geology and geotechnics associated with construction of the Thames Tunnel, part of the UK’s Channel Tunnel Rail Link (CTRL). The 2.5km long twin tunnels run beneath the river Thames at depths of up to 40m and are currently under construction. They pass through varying geology comprising alluvium, terrace gravels and chalk with flints and are currently being bored using Herrenknecht mixshield slurry tunnel boring machines (TBM’s). This paper outlines the lithology and engineering properties of each geological formation and describes the geotechnical processes, potential hazards and difficulties experienced in the works. A summary is given into the extent of the investigative work in terms of route selection, tunnel design, TBM optimisation and further details are provided on the geotechnical aspects associated with the construction of the tunnel approach structures and the tunnels.

Jan 1, 2003

By Takeshi Tanaka, Yasuhiro Komamura, Yuusaku Tominaga, Takayoshi Iwamoto

In order to assist better countermeasures for ventilation control in normal/abnormal condition of mine ventilation network in real time, branch relation table derived from a macroscopic characteristic of ventilation network is introduced in this study. The main results in this study are as follows; 1) One of macro characteristics of a ventilation network, as a relation between airflow rates in two branches chosen arbitrarily, is specified under the change of aerodynamic resistances in a branch. Airflow rate in a branch can be estimated by airflow rate in other branch changing aerodynamic resistance by using empirical formula. The empirical formula by computer simulation of the Horonai coal mine, Japan is considered to be a one-valued function with monotone or extremums. 2) A branch relation table shows the macro characteristics, mentioned above, of all the set of two-branch combinations in a network. Elements in the table give both information of control possibility range of airflow rate and total number of extremums in an empirical formula. 3) It is important that when aerodynamic resistance change in a branch is estimated by measuring airflow rates in two typical branches, the two branches should be chosen from branch combinations with monotonous relation in the branch relation table. 4) A flexible expert system to assist ventilation control in the specified branch in real time has been developed by using a branch relation table for a ventilation transfer diagram of the specified branch, such a coal face and an advancing face. A fuzzy reasoning is utilized in the recognition of the safety factor, methane concentration, in the system. And when conviction degree in recognition for methane concentration at the specified branch is too low, the system searches for other branch combinations in the branch relation table stored in the system, to use other ventilation transfer diagram of the specified branch. When a needed ventilation transfer diagram is not stored in the system, the expert system asks automatically the ventilation simulation from other computers linked to the main computer automatically. The system repeats consultation until conviction value of safety in the specified branch approached

Jan 1, 1993