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By N. Kacira

"Canada's largest known chromite deposit occurs in a layered intrusion in the Bird River area of Manitoba. However, numerically most of the chromite occurrences are in the Appalachians. Few, apparently minor, occurrences are also known in the Cordillera.In the Appalachians, chromite occurs as lenses and pods in dunite; they are of ""podiform"" type. The individual concentrations vary in size from a few pounds to tens of thousands of tons. Locally, chromite concentrations form discontinuous zones extending several hundred feet along strike and presumably down dip, therefore resembling boudinaged layers. Chromite layering and lineation are commonly concordant to those of the host rocks.The Appalachian chromite occurrences are thought to have been formed by fractional crystallization and perhaps also by liquid immiscibility. Their present shape and distribution are largely the result of deformation mostly prior to complete solidification of their host rocks. Therefore, the attitude of layering, foliation, lineation and other features related to deformation provide valuable guides in predicting the probable distribution of chromite, and hence are helpful in exploration.Chromites fulfilling the requirements for metallurgical, refractory and chemical grades occur in the Appalachians. Although the Appalachian deposits are similar in size and grade to some of the chromite deposits being mined elsewhere, they are unlikely to be economic, at present, in the higher wage Canadian environment. However, in case of shortages in chromite ore supply which may result, among other reasons, from increasing tendency to further processing in the producing countries, the Appalachian occurrences may become sources of ore. Such eventual shortages combined with relative abundance of electricity in Canada and recent innovations in oxide ore reduction technology may hasten the time when ferrochrome manufacture based on local chromite sources becomes economically viable."

Jan 1, 1982

By Timothy E. LaTour, Robert Kerrich

Microstructures and mineral chemistry of amphiboles and plagioclases from two spatially related mylonite zones at the Grenville front are significantly different, suggesting different physical conditions (including temperature) for the formation of the two zones. Oxygen isotopes indicate multiple episodes of fluid-rock interaction, consistent with previously determined mylonitization temperatures and postulated tectonic evolution of the area.

Jan 1, 1982

By G. B. Atkinson

Properties of catalysts prepared from intermetallic compound precursors were investigated by the Bureau of Mines as part of its mission to decrease U.S. dependence on foreign sources for scarce catalytic materials, such as nickel, cobalt, and chromium. Methods were developed whereby catalysts with surface areas of 30 to 40 m2/g were prepared from intermetallic compounds. Activity of these catalysts for the methanation reaction and methanol synthesis was deter-mined using a fixed-bed, single-pass, flow-through reactor. Catalysts prepared from rare-earth-nickel intermetallics had specific activity for methanation that was five times greater than that of commercial catalysts and were equal to or better than commercial catalysts with regard to sulfur tolerance. Under identical reaction conditions, catalysts prepared from thorium-copper intermetallics produced more than 10 times as much methanol as a commercial low-pressure catalyst and exhibited a high degree of catalytic stability.

Jan 1, 1982

By Douglas A. Sloan

"Recently, a number of major mining companies seemed unable to find a president from within the industry, and were searching outside the industry. From this, one could conclude that managers within the industry are either not being prepared or are not preparing themselves for presidential responsibility. Opinions were sought from a number of senior executives, to attempt to define the skills a prospective president should acquire and what actions a company could take or that a prospective president could take to acquire these skills.This paper contains summaries of the opinions obtained, along with the author's comments. The paper also describes the actions some companies are taking and the actions that an aspiring president can take to prepare himself for corporate management.IntroductionA manager is promoted up the management ladder when the manager's superiors believe that he is capable of handling a more senior position. Normally, the manager acquires this credibility by outstanding performance in his current management post, whether it be in a junior management (supervisory) or in a vice-presidential capacity.In most instances, the skills required for promotion can be acquired in the current position or, at worst, the abilities exhibited in a candidate's current role will convince his superiors that the necessary expertise for the more senior position can be acquired on-the-job. This is particularly the case when the new skills are felt to be an extrapolation of the old skills.However, in the case of appointment to presidential rank, there appears to be a need for new expertise which often is not acquired in normal management progression or, at least, boards of directors of some mining companies seem to believe this to be the case. The objective of this paper is to attempt to define the new skills that should be acquired by a manager who aspires to be the president, and to describe what actions might be taken by him to acquire them."

Jan 1, 1982

By Stan Henning

The monthly summary of the climatological record for the demonstration mine is presented in Table 1. Tear normal temperatures occurred throughout the growing season. From May to October precipitation was more than normal except in June when it was 2.55 inches below normal. Corn and soybean plantings were delayed until June 2-7 because of wet field conditions. This is about one month later than normal for corn planting. Insect infestations were much less than those encountered in previous years. Cutworm activity was not noticed and alfalfa weevil infestation were small and patchy. Stalk rot in corn was a significant problem at harvest and resulted in much Milk lodging. The wet and generally overcast conditions of July, August and September were bend 10 beneficial al to certain plant disease organisms. For example, pumpkins planted in a small garden area at the demonstration mine did not ripen because of a powdery mildew resulting from overcast, wet conditions. Field operations and row crop plantings were greatly delayed by wet field conditions. It was difficult to plant by conventional tillage because the soil remained soft and sticky where the moldboard plow had been used. Plots in the no-tillage system could he planted before conventionally tilled plots could be traversed. Plant emergence and plant density at

Jan 1, 1982

By J. H. Crocket, J. Andy Fyon

"All gold deposits within the Tisdale Group are spatially associated with carbonate alteration zones; however, not all carbonate alteration zones are host to gold mineralization.Within the komatiitic and magnesium tholeiitic volcanic rocks at the base of the Tisdale Group, discordant and stratabound carbonate alteration zones occur throughout. The alteration zones consist of a ferroan dolomite - quartz inner assemblage which is enveloped by calcite-quartz and an outer chlorite-rich subzone. Factors which control the distribution of carbonate alteration include joint systems, flow contacts, synvolcanic faults and bulk composition of the host rock.Two environments of carbonate alteration can be recognized: 1) The subsea-floor alteration zones developed within the volcanic rock succession where hydrothermal fluids did not discharge directly onto the sea floor. Insignificant gold production has come from this alteration environment. 2) Seafloor zones, which represent points of hydrothermal fluid discharge into the hydrosphere, are spatially associated with felsic volcanic rock complexes and are host to syngenetic, auriferous cherty dolomite.Carbonatized, magnesium tholeiitic basalts, which are host to the auriferous, cherty dolomite, are enriched in antimony (>0.35 ppm), boron (>30 ppm), gold (>5 ppb) and lithium (> 35 ppm), but are depleted in copper ( < 70 ppm), with respect to carbonatized basalts not associated with gold. Orerelated, altered komatiitic flows can be screened using gold (>5 ppb), lead(> 10 ppm), arsenic(> 70 ppm) and antimony (>1 ppm).The habit, petrographic characteristics and certain geochemical characteristics of the altered volcanic rocks suggest that the hydrothermal fluid was of sea-water origin."

Jan 1, 1982

By A. L. Rutledge, R. S. Nichols

"Waste dump development at the Fording River Operation s in British Columbia began in 1971. In 1981, several unique as well as unplanned situations provided an opportunity to study water flows through waste dumps.The key to the drainage is naturally segregated rock sizes .created by end dumping from the crest of a pile. The largest size material accumulates at the toe. Flow rates along the base of the studied dumps varied from 2,800 to 13,500 m3/day or 0.032 to 0. 156 m3/s (1.2-5.5 cfs}. Sediment concentrations in the water ranged from 1 to 1,800 mg/I.This paper describes water flows through dumps of varied lithology and maturity. The results suggest that neither long-term water flow nor contained sediments in small streams are jeopardized when crossed by end-dumped fills.IntroductionThe Fording River Operations are located in southeastern British Columbia approximately 115 km north of the United State s and 10 km west of Alberta, within the medial range of the Rocky Mountains. All production is carried out at elevations ranging between 1,600 and 2,200 m above sea level.The property is within a continental climatic zone, with temperature extremes of - 40°C in January to +35°C in July. The average annual precipitation of 335 mm of rainfall and 390 cm of snowfall feeds the numerous seasonal, small drainage courses along the Fording River valley.Since start-up in 1971, 149 million bank cubic met res of waste from truck-shovel and dragline mining have been placed in numerous dumps or ""spoils"". The dumps were developed to the point that several unique situations could be studied. During the peak run-off period of May-June 1981, water flow studies were performed on dumps of varied lithology and maturity. This paper describes the results of the study."

Jan 1, 1982

By Terry W. Engelhart

"A computer-based approach to online supervisory control and operations management of bulk materials handling terminals". This paper describes an integrated computer facility supporting the functions and responsibilities of shift operations, scheduling, maintenance and management using real-time interactive techniques. The functions and responsibilities as related to coal export terminals are specifically addressed, although these functions would be equally applicable to other terminal configurations and other commodities. A discussion of the resulting benefits are presented: - throughput efficiency - long-term planning and scheduling, using simulation - operations monitoring and protection - demurrage/despatch optimization - preventative maintenance - operational productivity

Jan 1, 1982

By O. Bergmann, R. E. Lueders, R. R. Ellefson, H. M. Brennecke, D. S. Davies

A new hydrometallurgical process has been developed to recover copper from sulfide ores. Copper is leached in a staged reactor system utilizing nitric and sulfuric acids at 105OC. Iron is removed from the pregnant liquor as a jarosite, and cathode copper is electrowon directly from the purified pregnant liquor. The spent electrolyte is recycled. Nitrogen oxides evolved from the leach are reconverted to nitric acid and are also recycled. Sulfur is rejected as So, jarosite, and gypsum. The process is highly versatile and can recover precious metals, molybdenum, and zinc when these elements are present. Continuous, integrated, semi-pilot plant operations using chalcopyrite ores demonstrated 99% copper leaching and production of cathode grade copper. Economic evaluation shows that the process is competitive with pyrometallurgical and other hydrometallurgical processes.

Jan 1, 1982

By James M. Spear

The U.S. Bureau of Mines and the U.S. Geological Survey conducted a mineral survey of the Elk Creek RARE II area during the summer of 1981. The study area encompasses 18,900 acres [29.5 sq mi (7,680 ha)] along Elk Creek, 18 mi (30 km) southeast of Covello, California. No mineral resources were identified by the U.S. Bureau of Mines during this survey. Assay results of samples taken in this area indicate only trace amounts of manganese and chromium. No radioactive or fluorescent minerals were detected. No oil and gas, coal, or geothermal leases have been recorded for the study area.

Jan 1, 1982

Improve the field-of-view into the front-right blind spot for drivers of large haulage trucks, thereby reducing the growing collision hazard in surface mines. Approach Reduce the glare problem found in the first generation fresnel lens blind area viewer design by eliminating the upward-looking section of the fresnel lens and adding a rear hood to reduce backlighting. How It Works The first generation blind area viewer was developed and in-mine tested as an aid to improved visibility for large haulage trucks. Other aids were improved left-and right-hand mirrors. Evaluations showed that a blind area viewer mounted on the right-front of the radiator deck was effective and was readily accepted by drivers. Nevertheless, because glare was a problem under certain conditions, a low-profile viewer was developed. Glare control louvers from the earlier design were kept and a backlighting glare control hood was added. The height of the hardware was reduced by eliminating the top three inches of the fresnel lens. This portion of the lens contained an upward-looking segment which originally was thought to be needed so the driver could see the horizon when he looked through the viewer and be better

Jan 1, 1982

By B. Yarar

Samples of coal from an adit in the Fording River District of British Columbia showed hydrophilic properties between depths of 0-24.5 meters and was naturally hydrphobic at higher depths. Laboratory experiments indicated that weathered samples (i.e., those mined at 0-24.5m) could be upgraded by froth flotation at pH<2 following slimes removal. The i.e.p. of samples varied regularly between pH=1.6-4.1, the weathered fractions being at the lower end of the pH scale. These values followed a pattern comparable with the flotation behavior of samples. A patchwise structure for coal surfaces determining the resultant disjoining pressure, which in turn determines flotation-non flotation relationships is postulated.

Jan 1, 1982

By Y. J. Wang

Optimal sizing of a ventilation shaft is a classical subject in mine ventilation economics.. The shaft size is optimized by minimizing the sum of shaft-construction and ventilation-power costs, or owning and operating costs. The length and air quantity of the shaft are held constant, and the location of the shaft, affecting its depth, and construction and ventilation power costs, is not considered (Hartman, 1961; Lambrechts, 1974; Wang et al., 1978). This paper proposes an approach by which the location and size for a new pair of shafts (intake and return shafts) are optimized for a coal-mine ventilation network. Specifically, the problem is to determine the location and size for a new pair of shafts, and the distribution of air between the new and old shafts so that the combined cost of shaft construction and ventilation power is minimized. The shaft length or depth corresponds to the height of overburden at any shaft location. To simplify the problem, the shaft locations will be limited to the line along the main or submain entries, and the connection entries at the shaft bottom neglected. In order to calculate the ventilation-power cost, the air power of the system should be determined. This in turn requires the calculations of the air quantity and pressure of each fan in the network, satisfying Kirchhoff&apos;s laws and Atkinson equation. After obtaining the air power, the cost calculation is straightforward. In the following, we shall assume that the resistances of all airways, and the quantity for each mining section, which is controlled by adjusting the air regulator, are all known. The resistances for the shafts are determined from the estimated friction factors, and shaft dimensions and lengths. Furthermore, it will be assumed that the fans can be selected to meet the duties called for by any network solutions.

Jan 1, 1982

By C. T. Sheeran, J. C. Franklin

A commercially available microprocessor-based system capable of monitoring 512 channels has been interfaced with monitors for radon, working level, air velocity, and fan power. The basic system utilizes both 280 and 8080 microprocessors in a desktop central processing unit (CPU). CPU hardware includes keyboard, video display (CRT), and disk drive; a printer is used to keep permanent data records. Signals from all channels are transmitted to the computer in digital form where they are processed for alarm status. Software developed for the system allows for audiovisual alarms in the event of low and high readings, rate change, change of state, or communica- tion failure. Up to six channels can be continuously displayed on the CRT for current readings. Shift reports and trend logs may be generated to help the ventilation engineer determine average working levels and ventilation effectiveness. Additional software permits the operator to program command sequences which may be used to automatically restart fans after a power outage.

Jan 1, 1982

By K. Ueda

Lead concentrates from Kuroko (black ore) mines, which contain Cu 4 ? 7%, Pb 55%, Zn 3 - 7%, As 0.5 - 0.9% are treated by hydrometallurgical process in order to smelt the product by electric furnace smelting together with other lead resouces from Kuroko. The hydrometallurgical pretreatment involves sulfuric acid leaching at first stage, ferric leaching at second stage. This paper describes the short history of lead recovery from Kuroko and the performance of laboratory test, pilot plant and commercial operation.

Jan 1, 1982

By G. M. Ritcey, K. E. Haque

"Laboratory-scale sulphuric acid leach tests were conducted on Elliot Lake and Rabbit Lake ores in the presence of various oxidants, namely: Fe2(SO4)3, CI2, H2O2, NaClO3, MnO2, H2SO5, HNO3, Oxon e, K2Cr2O7, KMnO4, O3 and O2. Uranium extraction is significantly accelerated when an oxidant is present in the leach slurry. Uranium extraction of 96-99% can be achieved by maintaining the oxidation potential of the leach slurry in the range of400 to 500 m V (S.H.E.). A rough cost comparison of all the oxidant s indicates that the use of Fe2(SO4)3, 02, O3, C12, HNO3 or MnO2 is far less expensive than NaClO3 and the uranium extraction rates are similar to or better than with NaCIO3. For uranium extraction, it is concluded that gaseous oxygen (i.e., air or oxygen) would be the most effective and economical oxidant for the 24- to 36-hour leach of Elliot Lake ore; whereas for the 8- to I2-hour leach of Rabbit Lake ore, a strong chemical oxidant (e.g. NaCIO3, H202, 03, K2Cr2O7, H2SO5 or HNO3) would be a logical choice.IntroductionThe common practice for the treatment of uranium o res is leaching with sulphuric acid or with a carbonate-bicarbonate mixture. Generally, the latter process is ad opted when an excess (> 18%) of acid-consuming components (e.g., carbonate) is present in the ore. Irrespective of the nature of the leachant, the addition of an oxidant to the leach mixture is necessary to obtain a high uranium extraction.The maximum extraction of uranium can only take place when all the uranium is in the highest oxidation state (i.e.,U +6-uranic ion) . Because a certain percentage of uranium present in the ore is invariably in the lower oxidation state (i.e.,U+4-uranous ion) , the addition of an oxidant to the leach slurry is necessary to oxidize uranous ion to the uranic state."

Jan 1, 1982

By Heinz W. Duddeck, Hans-Konstantin Nipp

The design of storage space or deep mining in rock salt should take into account not only time dependency of the rock salt behavior but also temperature effects. For deep mining of potassium salt the natural increase of temperature with depth may no longer be negligible. For the storage of cryogenic liquid gas in salt caverns more knowledge is nezded about the propagation of deep temperatures and their effects on the stress-strain-creep behavior of the surrounding salt. High temperature problems arise for nuclear waste storages in caverns or drill holes emitting radiation. A numerical model is proposed for the analysis of displacements and stresses including their time and temperature induced change. For the material behavior of salt constitutive equations are chosen composed of a combination of Hooke-Kelvin-Bingham-Newton-model based on experimental results (excluding at present deep cooling), Langer 1980. The parameters involved are depending on the stress level and the temperature. The finite-element-method is applied to rotationally symmetrical three-dimensional problems. The non-linear calculation method is based on an implicit method with respect to time. A modified Newton-Raphson-method and the initial strain approach are employed. Along with some experiences on suitable numerical procedures, examples are shown for the characteristical effects of time-temperature dependency. Having achieved convergency and reliability a method is now available for practical design and parametric sensibility studies.

Jan 1, 1982

By L. M. Falcon

Cassiterite is considered to be the only economically significant tin mineral in the earth&apos;s crust. In its purest form, cassiterite contains 76 per cent tin. The mineral is hard and heavy but also extremely brittle. and is therefore ideally suited to gravity recovery techniques. Cassiterite deposits can be categorized into two main types, i.e. alluvial or &apos;soft&apos; rock deposits, and &apos;hard&apos; rock deposits. The former are relatively simple to upgrade owing to their relatively coarse nature and their high degree of liberation. Hard-rock deposits, on the other hand, require considerably more sophisticated gravity methods to achieve the required degree of beneficiation. Various types of gravity recovery devices, both old and new, are described, and their respective roles in the flowsheets used are illustrated.

Jan 1, 1982

By Menne DM

The carbon-in-pulp (CIp)process has become well accepted and firmly established in the gold industry of South Africa and, at this stage, six large CIP plants are treating close to I million metric tons of material per month. Many small operators are also using CIP and additional large plants are either nearing completion, are on the drawing boards,. or are being considered. The programme of testwork that preceded the acceptance of the CIP process in South Africa was conducted over some eight years and has been previously described&apos;-7. With the start-up of the President Brand CIP plant on &apos;calcine&apos; in July 1980 and that of the Western Areas CIP plant on repulped filter residues in September 1980, the emphasis on the CIP process switched from pilot plants to these large plants - and has largely remained there. As it has started up, each new CIP plant benefited from the experience gained and the developments made, on earlier plants but, since so few plants have so far been established in South Africa, each new plant and each new design has revealed a further set of conditions to be met and problems to be overcome. However, in the highly collaborative atmosphere of the South African gold-mining industry, the results and observations from the operation of these first plants were shared by all mining groups. This paper will attempt to describe typical developments on, and results obtained from, these new large plants, and will incorporate significant results from the earlier laboratory and pilot-plant investigations.,

Jan 1, 1982

By P. B. Altringer

The Federal Bureau of Mines conducted a study to determine if residues from fractional distillation represent a potential source of mineral values. A literature review and discussions with tar sand specialists failed to disclose the mineralogical nature of residues remaining after bitumen extraction. To develop this information, pilot plant tar sand residues or toluene-cleaned tar sands from 23 deposits were examined. The nature of the residues was determined by standard mineralogical methods and the chemical compositions were determined by X-ray and ICP (inductively-coupled plasma spectroscopy). None of the sands or concentrates examined contained sufficient valuable minerals to be economically important.

Jan 1, 1982