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By M. Pawlik

Canadian sylvinites contain over 90% of KCl and NaCl and a few percent of water-insoluble minerals. Cationic flotation is used to produce KCl concentrates. Since water-insoluble minerals appear in the pulp as slimes, and since long-chain primary amines are utilized as a collector, desliming is essential. The potash industry utilizes different desliming methods. This may involve selective flocculation of the slimes with polyacrylamide and removal of the flocculated product by flotation, or mechanical desliming with the use of classifying cyclones. Whichever method is applied, desliming is never complete; the flotation feed after desliming still contains about one percent of the slimes which heavily affect collector consumption and flotation selectivity. Therefore, the remaining slimes have to be rendered inactive by “blinding” them with polymers such as carboxymethyl cellulose or guar gum. The commercial blinders used by the potash industry include natural and synthetic polysaccharides. The most common is the use of carboxymethyl cellulose (CMC) and guar gum (GG). These are quite different polymers, while CMC is anionic, GG is non-ionic; while the applied CMCs are of relatively low molecular weight (about 300,000) GGs have much higher molecular weight. Guar gums are also heavily used as the depressants of naturally floatable gangue in the processing of platinum-bearing ores, and according to Harris et al. (1999) quite a large variety of modified guar gums are available in South Africa for this application. Cheng et al. (2002) claim that natural guar gum’s molecular weight is 1.935 • 106. Robinson et al. (1982) found that the molecular weights of five grades of commercial guar gums ranged from 4.4 • 105 to 16.5 • 105. The highest molecular weight sample is then very close to the natural guar gum studied by Cheng et al. (2002). According to the manufacturer, the Rantec KP4000 guar gum which is used by the Canadian potash industry has a molecular weight of about 1.5 x 106. Since both KCl and NaCl are soluble in water, the flotation process is carried out in saturated brine. At 20 oC, 1450 kg of NaCl-KCl-H2O saturated solution contains about 0.300 kg of NaCl, 0.150 kg of KCl, and 1 kg of water (Gaska et al., 1965). Thus, in the saturated NaCl-KCl brine there are about 5.1 kmole of NaCl and 2 kmole KCl per 55.5 kmole of water. This gives 3.9 molecules of water per each ion assuming complete dissociation of NaCl and KCl. Thus, it is obvious that all water molecules in the saturated brine must be bound in the hydration shells around the hydrated ions. The surface tension of the NaCl-KCl saturated brine was recently measured to be 85 mN/m (Laskowski et al., 2003).

Jan 1, 2004

By W. C. Lacy

It is the responsibility of educators to look ahead and prepare young engineers and scientists to cope with industrial and social problems of the future. We are faced with a review of history as well as prophesy of the future. The mining industry exists in a "bubble" with little interaction or communication with the outside. This isolation must be broken down if the industry is to survive in the U.S. and Canada. The ability to communicate with the general public and public officials is essential. Many changes are occurring that will require readjustments in technology and staffing. Aging population will result in raising retirement and increasing available workforce. This may force shorter working weeks to supply additional jobs. Environmental concerns will likely direct more attention not only to these concerns during mining, but to planning for post-mining land usage. Retraining and up-dating educational programs are required to cope with these changes.

Jan 1, 1994

By Adolph V. Mitterer

International Minerals and Chemical Corporation operates one of six potash mines in the Carlsbad potash basin. More than 90 percent of America's potash is produced at Carlsbad and IMC accounts for about one-fifth of that amount, Since the Company began operations in 1941 it has mined nearly 50 million tons of ore. Of the two types of ore mined at Carlsbad the principal tonnage is sylvinite in which sylvite-potassium chloride-is the ore mineral. It is produced by IMC as well as by all other mines in the area, In addition to sylvinite IMC is the exclusive producer of langbeinite ore--potassium-magnesium sulfate. From its two ores, International produces a spectrum of 8 high-quality agricultural and industrial chemical products.

Jan 1, 1959

By Gordon B. French

The Occidental Oil Shale mining and retorting system for the production of shale oil has many advantages over the conventional underground mine and surface retort systems. For example only a portion of the oil shale is mined and transported to the outside, where it blends with the existing shale talus found on most of the slopes in the immediate area. The retorted spent shale is retained underground so that it does not become a surface disposal problem. The process consumes only minor amounts of water which is produced in adequate amounts in the retorting to fulfill all mining operations needs without outside supplies. Noise and dust levels are kept to a minimum with most of the facilities located underground. The exception being the generating stations and facilities as required to monitor air and water qualities, and last but not least, more than four times as much oil is pro¬duced from a given acre than from conventional surface processing. With the increased thicknesses as available on the government monopoly area this number could be increased by a substantial amount.

Jan 1, 1975

By Mike O’Brien, Rob Croll

The Evolution of AngloGold -Incorporated in 1944 under the name of Vaal Reefs Exploration and Mining Company Limited -Name changed to AngloGold Limited in 1998 as the vehicle consolidating the gold interests of Anglo American Corporation -Diversification (geographic and orebody) through the sale of low-margin, deep level, short-life assets and the acquisition of higher margin, open-pit and shallow underground operations

Jan 1, 2003

By M. W. Springett

During the 1970's geostatisticians were often accused of not paying sufficient attention to geologic features in the computerised generation of ore reserves. Unfortunately this charge was all -too-often justified and the results of such studies tended to be oversimplified and failed to reveal the full potential of computerised reserve estimation and geostatistical methods. There were some notable exceptions to this trend. Techniques were described that paid a great deal of respect to the geologic characteristics peculiar to certain deposits (Rendu J-M, 1984, Barnes T. E., 1982). At Gold Fields several techniques have been developed for handling the geologic characteristics of ore bodies for reserve estimation purposes. These have developed over time and the evolution of their adoption has been a reflection of our own learning experience from the practical application of computerised reserve estimation on many precious metal s deposits. Problems Typical problems that have been experienced by ourselves and which we have learned to guard against and watch for are: ? "smearing" at geologic contacts ? confusion caused by disparate "selective mining unit sizes" and block sizes ? conflicting estimates generated by field staff using various versions of the polygonal method ? problems in generating meaningful variograms

Jan 1, 1985

By J. A. Oraniscak

Longwall mining operations continue to increase extraction rates and the potential to generate higher amounts of airborne respirable dust (ARD). The National Institute for Occupational Safety and Health (NIOSH) has gathered data from underground longwall surveys and laboratory crushing tests to identify the important factors influencing the amount of ARD levels generated. Coal-seam characteristics, operational parameters (i.e.,cut sequence, mining height, etc.), extraction rates and dust-control parameters (i.e., airflow, water flow, etc.) were examined to determine their influence on ARD levels measured at longwalls during actual mining operations. ARD generated by a laboratory crusher while crushing bituminous coal samples collected from underground longwalls was also examined to determine if there were cor relations with coal-seam properties. Results from the longwall and laboratory data collected indicated that low-ash, high-volatile coals (low moist fuel ratio or MFR coals) generate higher amounts of ARD. It was found that face ventilation and water application to the coal product are essential elements to controlling longwall ARD levels.

Jan 1, 2000

By Gerald L. Colborne

The major role of financial institutions in the free world in the development of mineral resources is to provide the necessary capital in the form of loans to underwrite the development of these resources by the industry on a stable and continuous basis. This capital provided by the depositors to the bank must be invested in sound projects where the degree of risk is relatively small, the return on the investment is reasonable and the time to retire the loan is of short duration. Money is, therefore, one of the important ingredients along with technology, manpower and an exploitable resource that will provide a sound economic base in this region of development. Canadian banks are similar to banks of other western nations, although each country has some differences in their banking systems. The basic difference between the American and Canadian systems is that the former employs unit banking while the Canadian utilizes the more mobile branch system, which is prohibited or restricted in the United States and some other countries. Canadian banks are the subject of this paper, so, subsequent material will relate to Canadian banks unless indicated otherwise. It will be realized by everyone that the mineral industry is only one area of the economy in which the banks are interested and to cover the subject matter in the time allowed, the topic is restricted to mineral resource development. In Canada this is a vital sector of our economy and before we outline some of the details of financing and services involved in various aspects of mineral development, a review of the Canadian mineral industry is a necessary part of the sequence of presentation. The writer presents this material as a resource engineer advising a major bank in mineral matters, so the presentation may relate more to the financial problems of the developer

Jan 1, 1972

The Northside Storage Tunnel Project in Sydney includes over 20 km of TBM driven tunnels, over three km of declines and major caverns and pump rooms. The paper describes methods used for design on the project. Emphasis is given to the refinement of the use of empirical rock mass classifications, and to the use of discontinuum numerical methods. The use of empirical rock mass classifications in Sydney sandstone has usually led to conservative design because the systems are based on a random orientation of joints in the rockmass. Because the joint sets are usually oriented in a way that is beneficial for tunnelling, limits must be placed on the parameters used in the classifications system. The paper discusses these limits and the derivation of the parameters. The use of numerical methods in Sydney sandstone is discussed. Continuum methods have their uses, but discontinuum methods are preferred. The use of UDEC has been validated against a previous project, the New Southern Railway. Recommendations are given for UDEC models. In Sydney's geology, so advantageous for tunnelling, the challenges of this project have been to make the best use of the good conditions, while maintaining safety for the workforce and the future operators of the project.

Jan 1, 1999

By J. F. Abel, R. J. Spengler

Convergence measurement across the 17.4-m (57-ft) high shaft station/loading pocket at Mt. Taylor provided continuing verification of stability and safety. Three levels of instrumentation, consisting of three lines each, were installed and monitored. The instrumentation showed that the flexible lining restrained the adjacent rock. The flexible lining consisted of pea gravel with neat cement between rock and liner plate, wooden crush blocks between liner plate and steel ring beams. The loading pocket is elliptical, 11.6 x 9.6 m (38 x 31.5 ft) inside diameter. The crush blocks were designed to allow 15 cm (6 in.) of convergence. Maximum predicted convergence was 7.0 cm (2.75 in.), and 5.7 cm (2.25 in.) was measured. Convergence measurements also demonstrated decreasing deformation with respect to elapsed time and distance from the measurement station to the temporary bottom of the shaft excavation.

Jan 1, 1987

By John D. Morgan

The U.S. economy annually needs over 4 billion tons of new mineral supplies. The value of domestically produced energy and processed materials of mineral origin exceeds $175 billion annually, but domestic production of both raw and processed minerals is not keeping pace with demand.

Jan 1, 1974

The removal of tritium from tritiated water (-0.5 µCiIL) was studied by metallothermic reduction using aluminum. The influence of the three variables namely the aluminum powder amount, the NaOH concentration and the reaction time has been studied on the tritium activity reduction. The experimental results and statistical analysis showed that more than 85% of tritium can be removed from the tritiated water. Further work on the tritium recovery as well as efforts to totally decontaminate water by incorporating a cryogenic concept is currently pursued.

Jan 1, 1998

By F. S. Knoll

GENERAL INTRODUCTION Electrostatic separation has found a number of applications since its initial installation as a processing method. Three broad types of electrostatic installations are discussed in order to provide a practical guide for three widely divergent uses of electrostatic separation. Only operating and installation data are covered in detail. A detailed technical treatment on the various types of electrostatic separation described in this paper can be found in the literature by F. S. Knoll, J. B. Taylor and J. E. Lawer.8, 9 ELECTROSTATIC SEPARATION OF IRON ORE: WABDSH MINES, CANADA Introduction Electrostatic roll-type separator technology which had been in use in various forms since the 1920's evolved in the late 1940's when this separation process was developed and applied to the extraction of titanium bearing minerals from beach sands by J. H. Carpenter. Equipment design and industrial flowsheets developed for the recovery of rutile and ilmenite found new application in iron ore by chance in the year, 1956. From the time of the first beach sands plant, Carpco had developed other technology, gravity and magnetic separation to better serve the beach sands industry. It was in the fall of 1956 that an iron ore producer from the upper Michigan Peninsula sent a sample of jaspilite (fine-grained specular hematite in a jasper matrix) to Carpco's laboratory for the purpose of determining if a new high-intensity magnetic separator would be beneficial. Process Development W. P. Dyrenforth, while presenting a paper on the subject in the fall of 1957, recounts the laboratory tests. "High-intensity magnetic separators have been employed (for the beneficiation of iron ore) with some success and are still being investigated. Magnetic separation is a natural field of investigation, since iron and magnetism have been almost synonymous since ancient times. As a matter of fact, when Carpco first began investigating the possibilities of upgrading specular hematite, the first thought was in terms of magnetic separation; and the second thought was in terms of gravimetric separation. It was found

Jan 1, 1986

By E. Manev

Thin aqueous equilibrium film studies and surface tension measurements on a mixed surfactant system consisting of polyethylene oxide (a model frother) and potassium ethyl xanthate (a model collector) enable the interaction between the two surfactants at the air/solution interface to be elucidated. For the film containing the non-ionic frother, the interface was charged and addition of low concentrations of xanthate acted as a common electrolyte and reduced the thickness of the film inducing rupture. However, at high xanthate collector concentrations, the negative charge xanthate was found to interact with the non-ionic and caused a build-up of negative charge at the air/solution. Higher frother concentrations were necessary to produce non-rupturing thin films upon increasing the xanthate concentration.

Jan 1, 1992

By T. Dlokweni, A. Z. Toper, A. P. Squelch, R. G. Gürtunca

A collaborative research programme called 'DEEPMINE' was established in 1998 to investigate and research the problems of mining below three and five kilometres depths. Backfill is considered as an important support strategy to alleviate rockburst and rockfall problems in current depths and it will even become a more crucial mining strategy at ultra-deep level mining. In this paper, the evaluation and the application of the current backfill design criteria to the ultra-deep level mining environment are studied and a new backfill design criteria is proposed. The new criteria suggests that backfill should still be placed 60 - 70% of the area mined with a maximum fill to face distance of three metres. Furthermore, the vertical stress generated in backfill should be between 2 - 3 MPa at maximum 25 metres from the face at a corresponding strain value of maximum 10%.

Jan 1, 2001

By I. H. Gundiler

A pilot-plant flotation concentrate containing 21.6 g/t gold and 2 kg/t silver was used for this study. Base-line cyanide and thiourea tests showed 30-40% extraction of both gold and silver. After roasting (450-750C), the maximum gold extracted was 89% with thiourea and 76% with cyanide. Pressure oxidation tests were conducted following a statistical experimental design in a 2L laboratory autoclave at 10% pulp density, and the residues were subsequently leached in acidic thiourea solutions for 2h. Leach results were presented in the form of contour maps, and optimum autoclave conditions were determined for maximum gold extraction (93%). However, silver extraction was only 7% when gold extraction was maximized.

Jan 1, 1992

By P. T. Bissert, T. J. Lutz, J. A. Yonkey, G. T. Homce

"Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-theshelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m3/ min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification.IntroductionThe Mine Improvement and New Emergency Response Act of 2006 (MINER Act) was enacted in the United States in the wake of three mine explosions/fires that claimed 19 lives that year. Intended to help improve underground coal mine accident preparedness, the MINER Act includes provisions that target mine safety issues in areas such as emergency response planning, adoption of new technology, training and education, and mine safety standards enforcement (U.S. Mine Safety and Health Administration, MSHA, 2006). Section 13 of the MINER Act specifically directed the U.S. National Institute for Occupational Safety and Health (NIOSH) to provide for research into the effectiveness and viability of refuge alternatives for underground coal mines. This mandate culminated in the 2009 adoption of changes to Title 30 of the Code of Federal Regulations (30 CFR) mining health and safety regulations, requiring underground coal mines to provide mine emergency refuge alternatives and associated components, to provide a life-sustaining environment for persons trapped underground. Such refuge alternatives can be either self-contained mobile units or built-inplace facilities. The regulatory changes also include provisions establishing requirements for MSHA approval of refuge alternatives and their components, and among these provisions are numerous criteria for providing a safe breathable atmosphere under positive pressure within the refuge alternatives. One specific criterion for maintaining a safe refuge alternative atmosphere requires the inclusion of an air pressure relief valve that will activate at a maximum of 1.25 kPa (0.18 psi), or at a pressure above mine atmospheric pressure, in the refuge alternative, as specified by the manufacturer when the breathable air is supplied by a fan or compressor (MSHA, 2008)."

Jan 3, 2018

By Jim Gebhardt

Douglas W. Fuerstenau (DWF) grew up on a farm and in several small communities in rural South Dakota during the depression years, where he learned the value of hard work. Working hard can produce results but being clever and hardworking will give you a bright future. In his later school years, Fuerstenau’s family moved to Rapid City where his intellectual curiosity and capacity helped him graduate with a B.S. in Metallurgical Engineering from the South Dakota School of Mines and Technology in 1949. His technical interests led to graduate studies and completion of a master’s degree from the Montana School of Mines in 1950 and Sc.D. degree from the Massachusetts Institute of Technology (MIT) in 1953.

By C. R. McClung

"Molybdenum, in the form of molybdenite, is a common byproduct of many copper mining and concentrating operations. While the recovery of most copper sulfide minerals is principally liberation controlled, the recovery of molybdenite is much more complex, with fully liberated particles commonly lost to tailings.A geometallurgical investigation was undertaken of molybdenite from the Bingham Canyon deposit with the aim of determining what effects, if any, mineralogy and the mineralogical attributes of morphology, angularity, liberation and size have on molybdenite recovery in the processing circuit. A set of samples was collected from the ores and products of Rio Tinto Kennecott’s Copperton Concentrator. The samples were analyzed by normal polarized reflected light microscopy, X-ray diffractometry, and scanning electron microscopy using a Mineral Liberation Analyzer, revealing the presence of two distinct types of molybdenite, which are the two polytypes: hexagonal (2H) and rhombohedral (3R). The 2H polytype occurs as textbook-shaped particles in quartz-molybdenite veins located in the core of the deposit, while the 3R polytype occurs as disseminated, ball-shaped particles with a dull or frosted appearance along the margins of the mineralized intrusive body or central core. Each polytype exhibited metallurgical properties consistent with those reported in the literature. The 2H polytype is easily ground, kinetically “faster” floating and displays surface attributes that are amenable to higher rates of recovery. This commonly results in the production of a high-quality molybdenum concentrate under normal operating conditions at most copper concentration operations. The 3R polytype is difficult to grind, kinetically “slower” floating and displays surface attributes that are less amenable to recovery. Therefore, in deposits with higher concentrations of the 3R polytype, modifications to operating parameters may be necessary to improve the recovery of molybdenite.A preliminary investigation into the metal budget of porphyry copper and molybdenum deposits indicated a possible positive correlation between total economic metal budget and polytype content. Higher concentrations of the 3R polytype appear to be more prevalent in gold-enriched porphyries than in molybdenum-enriched porphyries. This may help explain why it is easier to obtain higher rates of recovery in molybdenum ± tungsten-rich deposits, which contain little to none of the 3R polytype. There is a potential for the metal budget of a porphyry deposit to be used as an indication of the molybdenite polytype present as well as its impact on the economics, in terms of exploration, and the processing circuit, in terms of plant design."

Jan 1, 2016

By Denis Murphy, James Gusek, Carl Mann, Thomas Wilderman

An active underground lead mine produces water having a pH of 8.0 with 0.4 to 0.6 mg/L of Pb and 0.36 mg/L. of Zn. This water is pumped at the rate of 1.200 gpm into a five-cell, bioreactor system covering about 5 acres. The gravity flow system is composed of a settling basin followed by two anaerobic bioreactors arranged in parallel which discharge into a rock filter polishing cell that is followed by a final aeration polishing pond. The primary lead removal mechanism is sulfate reduction/sulfide precipitation. The discharge has met stringent in-stream water quality requirements since its commissioning in 19%. However, there have been startup and operational difficulties. The system was designed to last about 12 years, but estimates suggest a much longer life based on anticipated carbon consumption in the anaerobic cells.

Jan 1, 2000