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By William W. Adams

A general increase in employment prevailed in the stone-quarrying industry of the United States during 1941 compared with 1940. Likewise, more accidents occurred to men working in and about the quarries, with the result that the accident-frequency rate for the industry as a whole was higher in 1941 than in the previous year. Reports from operating companies to the Bureau of Mines, covering open and underground quarries, as well as rock-crushing and rock-dressing plants, cement mills, and limekilns at or near the quarries, showed a total of 86,123 men employed and a total of more than 22 million man-days of labor performed during 1941. The total working time of the industry averaged 260 days per man. Measured in man-hours, the volume of work equaled 173 million, an average of 2,011 man-hours per employee.

Jan 1, 1943

By William W. Adams

The quarrying and related industries of the United States made a large gain in employment (man-hours of work) in 1942 with a somewhat smaller number of men employed than in 1941. This was accomplished chiefly by increasing the number of workdays per man and also by increasing the length of the workday. In spite of the greater volume of work performed, the industry had a more favorable accident-frequency rate in 1942 than in the previous year. Accident and employment reports from operating companies showed that the industry employed 84,270 men for an average of 271 days per man in 1942, with a volume of work of almost 181 million man-hours. The average workshift comprised 7.93 hours, and the number of man-shifts worked totaled nearly 23 million. Injuries from accidents in and about the quarries and plants caused disability to 6,461 employees, 112 of whom died as a result of their injuries, including 28 employees whose lives were lost in a single disaster. The accident-frequency rate in the industry was 35.73 per million man-hours worked, comparing favorably with a rate of 40.11 for the previous year. However, the figure for 1942 included a death rate of 0.62 per million man-hours which, because of the disaster referred to, was considerably higher than the fatality rate of 0.44 for 1941. Had the disaster not occurred, the fatality rate for the industry for 1942 would have been 0.46. The major disaster in which 28 lives were lost occurred on March 26 at the Sandts Eddy quarry of the Lehigh Portland Cement Co. near Easton Pa.

Jan 1, 1944

By Oliver Bowles

Lime is of tremendous importance to modern industries. In agriculture it is regarded as essential to the continued fertility of many important regions; in building it is indispensable, and in the many ramifications of the chemical industries it is so necessary and so widely employed that it has been designated "the king of all the bases." Figure 1 shows a general view of a modern lime plant producing more than 500 tons of lime daily. In 1924 the production of lime was reported from nearly every State in the Union and amounted to more than 4,000,000 tons, valued at, nearly $40,000,000. For a production of that magnitude between 8,000,000 and 9,000,000 tons of limestone are required. The many problems involved in winning this great quantity of raw material from the natural rock and preparing it for the kilns have in the past received little attention from any governmental agency. Therefore, in compliance with a request from representatives of the National Lime Association in 1922, the Bureau of Mines began a study of problems in limestone quarrying in an effort to advance more economical methods of operation and the utilization of waste material. Field studies were made at many quarries, and the information thus compiled, besides data already at hand from work in other branches of the stone industries, were disseminated to operators in the form of mimeographed Reports of Investigations, eight of which were issued at intervals during 1922, 1923, and 1924. A questionnaire was appended to each report, and quarry operators were invited to contribute additional information obtained as a result of their actual experience and observation. Operators of lime plants have been cordial in their responses and have supplied the bureau with much valuable information. From the data thus obtained, supplemented by later field studies, the revised reports have been combined to form the major part of this bulletin, which is believed fairly to represent present knowledge on the subject of quarrying limestone for lime manufacture.

Jan 1, 1927

By E. G. Hoover

In the mid-I 970s the rallying cry sent out by the aggregate trade associations to aggregate operators was to come to Washington and help design national legislation mandating reclamation of pits and quarries. This collective effort paid off in that aggregate operators were able to assist in the design of "livable" legislation; however, the coal mining industry took some very hard hits. A principal argument used by the aggregate industry was that relatively small parcels of land are impacted, the operations are located in or near urban areas to serve in the development of that immediate area, and are of many years duration; whereas, coal strip mines disturb many acres, are of short duration, and whose products may have world or nationwide utilization. Historically, developments in reclamation are tied closely to the regulatory systems that have been created to control environmental effects of mining. Since reclamation generally results in a cost incurred after the stone, sand and gravel has been mined and does not add to the inherent value of the mineral, there was little incentive in the past for mine operators to reclaim the land. In 1977, the Surface Mining Control and Reclamation Act (SMCRA) became the law for coal mine operators. The law states that, among other provisions, reclamation must "restore the land affected to a condition capable of supporting the uses which it was capable of supporting prior to any mining, or higher or better uses". It is of interest to note that years before the initiation of legislation leading to SMCRA twenty-eight states already had reclamation regulations that covered virtually all minerals. The scope of performance standards found in the state reclamation regulations included slope stabilization, grading, revegetation, neutralization of toxic materials, visual screening, waste disposal, control of drainage, and other sources of pollution and erosion. Environmental legislation and the consequent regulations came about because the public perceived that private industry did not properly value environmental quality and as a result the government became the policeman.

Jan 1, 1998

By L. C. Johnston, J. N. Gills

This paper reviews the basic reactions of the blast furnace and the open hearth furnace, and then discusses the quarrying and sizing requirements of the limestone feed for each. Particular emphasis is placed on the lime-stone at Irish Cove, now being mined under an agreement between Scotia Limestone Limited and Dosco Steel Limited. The drilling and blasting operations are described, along with loading and haulage, plant flow, water supply, power supply and transportation facilities.

Jan 1, 1967

By P. F. MINISTER

AT Lime Spur, Mont., the East Butte Copper Mining Co. has been quarrying limestone for twenty years. The quarry is beside the Northern Pacific R. R. in the Jefferson River canyon, 4 ½ miles east of Cardwell, at Lime Spur, Montana. HISTORY This quarry was opened early in 1900 by Dan Morrison of Whitehall, the discoverer of the Morrison cave, to supply a demand for smelter flux. Limestone was sold to the Pittsmont smelter of The East Butte Copper Mining Co. and to the Butte Reduction Works. As no particular effort was made at the quarry to select the rock that delivered to the smelters was unduly high in magnesia and impurities. The East Butte com¬pany, therefore. Bought the quarry. in 1909 and confined operations to the high-grade beds in order to supply rock of the desired purity for its own smelter and the Butte Reduction Works until the latter shut down. It also developed a market for some of its rock with the sugar factories. The latter market increased until in later years all rock, larger than 4 in. in size over a bar grizzly, was being shipped to the sugar factories, and the rock smaller than 4 in. was being used as a flux in the blast furnaces at the Pittsmont smelter. In 1924, the East Butte concluded a contract with the Anaconda company for the treatment of its ores, and the Pittsmont -smelter -was shut down: which made the minus 4-in. rock a useless by-product. Since there was not enough revenue in the sugar rock alone and also because of limited waste room it became necessary, if Lime Spur was to continue to operate, to increase- the proportion of plus 4-in. rock and to develop a market for the minus 4-in.

Jan 1, 1930

By Harry Leslie Bullock

With silica making up more than 27% of the earth's crust, its oxides amounting to more than 59% of the igneous rocks and quartz the most prevalent of the main free oxides, it follows that the mining engineer' is in constant contact with quartz, mainly as a gangue material to be removed as completely and economically as possible and sometimes as a valuable mineral to be purified' for the chemical,, ceramic or glass industries. Water scarcity under desert or semi-arid conditions, dwindling water supplies and difficulties of wet waste disposal in many locations and trouble from freezing in arctic locations make dry benefication more and more desirable. Advances made during the last few years in apparatus and methods and a steadily increasing knowledge of solid state physics are widening the field open to the economical application of electrostatic separation.

Jan 1, 1967

By J. Kou

In this paper the activation behavior of quartz using Ca(OH)2 as an activator in quartz reverse flotation with anionic collector was evaluated and their adsorption behavior was investigated using a variety of techniques. The adsorption of the collector KS-I on the surface of quartz with and without Ca2+ was primarily characterized using Quartz Crystal Microbalance with Dissipation technique (QCM-D), which is a high sensitivity in-situ surface characterization technique. The flotation performance was evaluated using a laboratory mechanical flotation cell at different process parameters such as pH, collector dosage, and Ca(OH)2 dosage. The anionic collector evaluated was a commercial fatty acid KS-I. The QCM-D data showed that the collector adsorbed on quartz more readily with Ca2+ as activator. The mass and structural property of the collector layer adsorbed on quartz surface at 2.16×10-3 mol/L of Ca2+, 0.3 g/L of collector and pH 12.0 have been studied using the technique of QCM-D. The chemisorption of the collector KS-I on the surface of quartz in presence of Ca2+ were also demonstrated by means of zeta potential, QCM-D and FTIR analysis.

Feb 23, 2014

By R. V. Ramani, W. Miola

"A relationship exists between the quartz contents in the underground coal nine airborne dust samples and those in the coal and host rocks that are mined [17, 18, 19] The prescribed method for quartz analysis in respirable airborne coal dust samples is the MSHA P-7 method. Accurate quartz analysis procedures are needed for bulk samples in order to predict the potential quartz content in airborne nine dust, which in turn will aid the design of quartz dust control procedures during mining. thereby reducing the airborne quartz dust in underground atmospheres. The requirements of this method are that the amount of quartz is the sample be less than 250ug, and the total sample weight less than 2,500 ug. Unlike with airborne dust samples, there are no limitations to the available mass of bulk samples. However, these are no standard procedures for the preparation of bulk samples for scanning or prescribed methods for quartz analysis. The NIOSH and MSHA methods are certified for roped* dust and the acceptance of these methods for bulk samples assumes that the bulk samples will be reduced to the conditions specified for respirable dust samples. An alternative method is X-ray diffraction, which provides higher average quartz values than those obtained from P-7 method for the same samples.An investigation was carried out to determine the optimal procedure for preparing the bulk samples for the IR and XRD analyses. In this paper, the investigations on the effects of calibration, particle sizes, matrix composition, interferrous, and behavior of the filter substances on IR, XRD and FTIR results are presented. The error introduced by the presence of kaolinite and a new sample asking procedure to reduce it are discussed. The problems experienced with conventional sample holders for scanning were eliminated with the design and development of a new hollow sample holder. Quantitative comparison of quartz determinations by IR, XRD and MR methods on coal, roof and floor rocks, and airborne dust samples are presented. The important factors affecting the results of quartz analysis methods are: 1) bulk sample preparation for obtaining representative and homogeneous analysis samples: 2) particle size distributions of the analysis samples and calibration standards; 3) qualitative matrix composition of the analysis sample; 4) matching calibration standards to analysis sample; 5) substrates for sample deposition during analysis sample preparation; 6) procedures for analysis sample mounting; 7) selection of proper portions of she response profile for insanity measurement; and 8) interferences of spurious phases with the critical analyses. The recommendations of this study are important to enable comparisons and interpretations of analysis and research results."

Nov 1, 1995

By Raja V. Ramani, Wilson Miola

The potential health effects of quartz-bearing airborne dust in mine and mill atmospheres point to the need for the quantification of quartz content in the source material for determining the source-sink relationships and for choosing applicable control measures. While a standard method exists from a regulatory point of view for the sampling of coal mine atmospheres for determining (i) respirable dust concentrations and (i) the amount of quartz in thesamples, there is no generally accepted standard method for quartz analysis in bulk samples of coal and host rocks. Generally, the bulk sample is reduced to a powder for producing quartz analysis samples. Extensive controls are necessary to ensure representativeness of the analysis samples when these are very minute fractions of the bulk samples. Since the amount of analysis sample is not limited, alternative methods for quartz analysis may also be tried. It is, however, necessary to adopt a procedure which will satisfy several statistical requirements to guarantee representativeness of the quartz analysis samples. In this paper, the important factors in the preparation of quartz analysis samples from the host rocks and bulk samples are discussed. The method developed to prepare the analysis samples is outlined. The results of application of the procedures are presented. The procedure developed for quartz analysis sample preparation is based on sound statistical foundations. The procedure has been validated for reproducibility and homogeneity.

Jan 1, 1991

By Raja V. Ramani, Wilson Miola

"The potential health effects of quartz-bearing airborne dust in mine and mill atmospheres point to the need for the quantification of quartz content in the source material for determining the source-sink relationships and for choosing applicable control measures. While a standard method exists from a regulatory point of view for the sampling of coal mine atmospheres for determining (i) respirable dust concentrations and (ii) the amount of quartz in the samples, there is no generally accepted standard method for quartz analysis in bulk samples of coal and host rocks. Generally, the bulk sample is reduced to a powder for producing quartz analysis samples. Extensive controls arc necessary to ensure representativeness of the analysis samples when these are very minute fractions of the bulk samples. Since the amount of analysis sample is not limited, alternative methods for quartz analysis may also be tried. It is, however, necessary to adopt a procedure which will satisfy several statistical requirements to guarantee representativeness of the quartz analysis samples.In this paper, the important factors in the preparation of quartz analysis samples from the host rocks and bulk samples are discussed. The method developed to prepare the analysis samples is outlined. The results of application of the procedures are presented. The procedure developed for quartz analysis sample preparation is based on sound statistical foundations. The procedure has been validated for reproducibility and homogeneity.The current methods used for quartz analysis in powders are the P-7 infrared spectrometry and quantitative X-Ray Diffraction (XRD). Both have similar restrictions concerning the sample characteristics and operational problems, which arc intrinsic to radiation beams, device geometry, mechanics and controls of the radiation behavior. Although improvements can be made in the spectrometers and diffractometers, some of the most important steps are the procedures for analysis sample preparation from bulk samples and for calibration of the instruments. The sample preparation process is often referred to as one of grinding and sizing the bulk sample to generate the powder for the scanning devices. The particle sizes are referred to and their influence emphasized but the representativeness of the sample is assumed. Assuring sample representativeness during the sample preparation procedures is critical.For the sampling of airborne respirable dust in coal mines, the collection devices, the collection procedures and the analysis procedures are defined. This is not true for bulk samples where weights must be reduced thousands of times to generate the analysis samples for the scanning devices. The specifications to be developed may include bulk sample amount, sample reduction procedures, sample particle size distribution and sample amounts. However, the common problem of insufficient sample amount which is often encountered with mine airborne dust samples need not exist for bulk samples. Further, the same bulk sample can yield analysis samples for several experiments. The latter, of course, requires sample homogeneity.Three concepts are important in the selection of any procedure for sample preparation and analysis. These arc accuracy, reproducibility and representativeness. The adopted procedure has to guarantee a homogeneous sample representative of the population, a defined level of accuracy and reproducibility. Important statistical concepts are embedded in these requirements, particularly with respect to estimation and dispersion errors. Accuracy and reproducibility are totally different though not independent concepts. Estimation is related to accuracy and the true value. Dispersion is related to reproducibility and is measured by the classical statistical standard deviation of the distribution of a series of measurements or analysis performed over the same lot or analysis sample. The dispersion variance (or dispersion error) does not tell a"

Mar 1, 1992

By Jianmin Qin, Raja V. Ramani, Wilson Miola

"The number of underground work entities operating under reduced dust standards in U.S. coal mines has been increasing since the start of the decade of the 80s and is currently approaching 10,000. The concern for controlling the quartz levels in airborne respirable dust in coal mine has manifested itself in several improvements in equipment selection and operation, face ventilation practices, and dust control procedures. At the same time, fundamental studies have been initiated on determining the source-sink relationships of the airborne quartz dust. The P-7 method is the prescribed method for the determination of quartz in the respirable airborne dust samples from coal mines. Questions have been raised on the reliability of the P-7 infrared spectrometry method for quartz analysis in powders. No specific method has been defined for quartz determination in bulk samples from the mine.In a recent study on the relationship between quartz in the airborne dust and that in the materials being mined, both infrared (IR) and x-ray diffraction (XRD) methods were used on a suite of samples from several coal mines. These samples encompassed airborne respirable dust samples, airborne total dust samples, the oversize fraction from the respirable samplers, ROM samples, channel samples, and chip samples from the face, roof, and floor materials. In this paper, the sample preparation and analysis procedures for the samples are discussed. The data, analysis results, and comparisons of the P-7 and XRD results are presented. The quartz percent determined for the same sample by the two methods are different. In 85% of the samples analyzed, the quartz percents determined by the XRD method are higher than those obtained by the P-7 method. However, there is a strong linear relationship between the results from the two methods. Further, the XRD method indicates an average of 20 percent more quartz than that from the P-7 method. The reasons for the differences in the results and the need for additional studies are explored.Since the enactment of the Federal Coal Mine Health and Safety Act of 1969 and the Federal Occupational Safety and Health Act of 1970, the prevalence of free silica as an occupational hazard in dusty work environments has been a matter of increasing concern. In underground coal mining, sometimes, roof, floor, clay veins and other non-coaly material must also be mined along with the coal. Mining these materials may increase the amount of quartz in the airborne dust (Pimentel and Adam, 1985; Taylor et al., 1984; Colinet et al., 1985). The problem of high quartz levels in the respirable airborne dust is widespread in continuous miner sections. In addition to the need for controlling the silica amount in mine atmosphere, a need for a sensitive, easily performed method for the determination of free silica in airborne dust samples was also recognized."

Mar 1, 1992

By Jianmin Qin, Raja V. Ramani, Wilson Miola

The number of underground work entities operating under reduced dust standards in U.S. coal mines has been increasing since the start of the decade of the 80s and is currently approaching 10,000. The concern for controlling the quartz levels in airborne respirable dust in coal mine has manifested itself in several improvements in equipment selection and operation, face ventilation practices, and dust control procedures. At the same time, fundamental studies have been initiated on determining the source-sink relationships of the airborne quartz dust. The P-7 method is the prescribed method for the determination of quartz in the respirable airborne dust samples from coal mines. Questions have been raised on the reliability of the P-7 infrared spectrometry method for quartz analysis in powders. No specific method has been defined for quartz determination in bulk samples from the mine. In a recent study on the relationship between quartz in the airborne dust and that in the materials being mined, both infrared (IR) and x-ray diffraction (XRD) methods were used on a suite of samples from several coal mines. These samples encompassed airborne respirable dust samples, airborne total dust samples, the oversize fraction from the respirable samplers, ROM samples, channel samples, and chip samples from the face, roof, and floor materials. In this paper, the sample preparation and analysis procedures for the samples are discussed. The data, analysis results, and comparisons of the P-7 and XRD results are presented. The quartz percent determined for the same sample by the two methods are different. In 85% of the samples analyzed, the quartz percents determined by the XRD method are higher than those obtained by the P-7 method. However, there is a strong linear relationship between the results from the two methods. Further, the XRD method indicates an average of 20 percent more quartz than that from the P-7 method. The reasons for the differences in the results and the need for additional studies are explored.

Jan 1, 1991

By W. Miola

The MSHA prescribed method for the determination of quartz in airborne respirable dust samples from underground coal mines is the P-7 method, a combination of low temperature radio-frequency ashing (LTA) and infrared analysis (lR). There is no prescribed procedure for quartz analysis in bulk samples of coal and host rock. Dispersive Infrared (IR), Fourier-transform Infrared (FTIR), and X-Ray Diffraction (XRD) methods are most commonly used for quartz analysis in powders. Several aspects of the experimental procedures such as the analysis sample preparation from bulk samples, ashing techniques, scanning procedures, peak measurement location, calibration techniques, sample amounts, size consist, and data interpretation affect differently the results from each of the methods. Significant differences in analysis results from X-ray diffraction (XRD) and infrared spectroscopy (IR) on the same samples are reported. All these studies point to the need for reliable quartz analysis methods. In a recent research, a procedure for preparing bulk coal and host rock samples for quantitative quartz analysis was developed. Further the results from X-ray diffractometry and infrared spectroscopy for quartz content on identical samples were compared. Calibrations with pure and mixed standards were used to assess the influence of particle size distribution, matrix, and calibration on analysis results. In this paper, several issues with the measurement of quartz in the samples of coal, host rock, and airborne respirable dust from mines are outlined and quantified.

Jan 1, 1994

By W. Miola, R. V. Ramaoi

"The MSHA prescribed method for the determination of quartz in airborne respirable-dust samples from underground coal mines is the P-7 method, a combination of /ow-temperature, radio-frequency ashing (LTA) and infra7 red analysis (IR). There is no prescribed procedure for quartz analysis in bulk samples of coal and host rock. Dispersive infrared (IR), Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) methods are most commonly used for the analysis of quartz in powders. Several aspects of the experimental procedures, such as the preparation of the analysis sample from bulk samples, ashing techniques, scanning procedures, peak measurement location, calibration techniques, sample amounts, size consist and data interpretation, affect the results from each of the methods differently. Significant differences in analytical results obtained from X-ray diffraction (XRD) and infrared spectroscopy (IR) on the same samples are reported. All studies point to the need for reliable quartz analysis methods.In a recent research program, a procedure for preparing bulk-coal and host-rock samples for quantitative quartz analysis was developed. Further, the results from X-ray diffractometry and infrared spectroscopy for quartz content on identical samples were compared. Calibrations with pure and mixed standards were used to assess the influence of particle-size distribution, matrix and calibration on the analytical results. In this paper, several issues concerning the measurement of quartz in the samples of coal, host-rock and airborne respirable dust from mines are outlined and quantified. IntroductionThe literature on coal-mine airborne-dust control has identified a need for a better understanding of the sources, mechanisms and amounts of quartz in mine airborne respirable dust (Althouse, 1984; Jankowski, Nesbit and Kissel, 1985; Ramani 1988; Qin, 1988; Bhaskar and Xu, 1990; Bhaskar and Li, 1992; Ramani, Qin and Miola, 1991 ). To understand the quartz content in the source materials, bulk samples of coal and host rock must be analyzed. Establishing an analysis procedure for determining the quartz content in bulk-coal and host-rock samples is necessary for identifying the sources of quartz in mines; for establishing the relationships between the quartz contained in the source and in the airborne dust; and for controlling the content of quartz in the mined product and in the airborne respirable dust."

Dec 1, 1996

By R. V. Ramani, W. Miola

The MSHA prescribed method for the determination of quartz in airborne respirable-dust samples from underground coal mines is the P-7 method, a combination of low-temperature, radio-frequency ashing (LTA) and infrared analysis (IR). There is no prescribed procedure for quartz analysis in bulk samples of coal and host rock. Dispersive infrared (IR), Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) methods are most commonly used for the analysis of quartz in powders. Several aspects of the experimental procedures, such as the preparation of the analysis sample from bulk samples, ashing techniques, scanning procedures, peak measurement location, calibration techniques, sample amounts, size consist and data interpretation, affect the results from each of the methods differently. Significant differences in analytical results obtained from X-ray diffraction (XRD) and infrared spectroscopy (IR) on the same samples are reported. All studies point to the need for reliable quartz analysis methods. In a recent research program, a procedure for preparing bulk-coal and host-rock samples for quantitative quartz analysis was developed. Further, the results from X-ray diffractometry and infrared spectroscopy for quartz content on identical samples were compared. Calibrations with pure and mixed standards were used to assess the influence of particle-size distribution, matrix and calibration on the analytical results. In this paper, several issues concerning the measurement of quartz in the samples of coal, host-rock and airborne respirable dust from mines are outlined and quantified.

Jan 1, 1996

By Dian Adisty, Leiv Kolbeinsen, Eli Ringdalen

In Si and FeSi production, the main Si source is SiO2, in the form of quartz. Reactions with SiO2 generate SiO-gas that further reacts with SiC to Si. During heating, quartz will transform to other SiO2 modifications with cristobalite as the stable high temperature phase. Transformation to cristobalite has been investigated and shown to be a slow process where the rate varies between the investigated quartz types. The effect of quartz versus cristobalite as SiO2 source has been studied for reaction (1) 2SiO2 + SiC = 3SiO + CO, by heating of pellets with SiO2 + SiC in Ar-gas. The reaction was faster with cristobalite than with quartz. Initial experiments indicates that this is the case only in Ar and not in CO-atmosphere The higher specific surface area of cristobalite is believed to contribute to the higher rate. The industrial consequences of the observed difference between quartz types are discussed.

Jan 1, 2014

By Jehan Rondot

Les bancs de quartzite inhabituellement purs et epais decouverts lors de la cartographie geologique de la region de Charlevoix sont maintenant entres au stade de !'exploitation et se revelent etre une richesse naturelle durable pour cette region. Les etudes stratigraphiques effectuees dans cette partie (Quebecia) du bouclier canadien indiquent que la succession: lo. complexe a amphibolite et leptynite a la base, 2o. quartzite et gneiss a sillimanite, muscovite et gneiss calcosilicate et conglomeratique au sommet est constante sur de grandes distances (de Charlevoix a la Basse Cote Nord) et represente une sedimentation continentale et de plateforme, peu epaisse, du proterozotque inferieur. La purete et la grande epaisseur du quartzite s'expliqueraient par un processus de sedimentation continentale complexe ou se succedent climat tropical-humide et glaciaire-aride et transport fluviatile et eolien. Parmi la multitude de depots de quartzite qui existent dans le monde, peu sont de qualite superieure. Or, de par sa composition chimique, le quartzite de La Galette se compare avantageusement a ceux des meilleurs gisements des Etats-U ni s, de l'Europe de l'Ouest et de I' Afrique du Sud. D'acces facile pour l'exploitation, les gisements ne sont qu'a une quarantaine de kilometres de Baie Saint-Paul ou de La Malbaie, sur le SaintLaurent. L'utilisation en metallurgie du quartzite de La Galette comprend la production de silicium, de ferro-silicium et d'autres alliages de silicium . La composition du quartzite est en outre appropriee pour la production de carbure de silicium et de silicate de sodium. Les fines peuvent etre utilisees pour la fabrication du verre et comme matiere de charge.

Jan 1, 1984

By D. Y. Li, C. D. Ma, T. Zhou, T. J. Cheng

In this paper, a number of experimental tests are carried out to study the strength difference on rectangular prismatic marble specimens with different height-to-width (H/W) rations. The specimens have a nominal size of 45×15 mm in the compressive cross-section (W×T) and different heights (H = 22.5 mm, 45 mm, 60 mm and 90 mm). It is to say that the height-to-width ratios are equal to 0.5, 1.0, 1.33 and 2.0, respectively. The quasi-static uniaxial compressive tests are finished by a servo-controlled INSTRON machine (the strain rate at about 10-5/s), and the dynamic compressive tests are finished by a diameter of 50 mm cylindrical SHPB apparatus (the strain rate reaching about 101/s). The rock failure process of marble specimens is captured by a high speed camera in order to distinguish the fracture propagation behaviour. It is found that the compressive strengths increase when the H/W ratio of marble specimen changes from 2.0 to 1.0 due to the end clamping effect both for quasi-static and dynamic loads. However, when the H/W ratio changes from 1.0 to 0.5, the apparent compressive strengths decrease both for the two loading conditions. The strength decrease of short marble specimens may be attributed to the change of failure mode from shear to slabbing, which can be identified by the fracture patterns of the specimens. Based on the uniaxial compressive tests, the slabbing strength of the marble was found to be about 40% of its UCS for the specimens with a nominal height-to-width ratio of 2.0. In addition, it is found that the dynamic increase factors (DIF) are affected by the specimen’s aspect ratios. It implies that the same aspect ratios should be used to compare the dynamic and static compressive strength of rocks. Meanwhile, both the static and dynamic tensile strengths of the marble are obtained by the Brazilian disc tests. The ratio of the dynamic tensile strength to the static tensile strength of the marble is about 2.68.

Jan 1, 2015

By V. F. Hollister

The Queen Charlotte gold deposit (also known as the Specogna, Babe, or Cinola) was discovered in late 1970 by Efrem Specogna and Johnny Trico. They were prospecting along the trace of the Sandspit fault, and they sampled jarositic material that included veins from the fault zone. Their assays included some good gold values. They located the Babe Claims in 1971 and optioned them to Kennco Explorations Ltd. Kennco conducted stream sediment and soil geochem studies, geological mapping and drilling of 55.2 m (181 ft) in two drill holes. Kennco withdrew from the property, and by 1977, Cominco, Placer Development, Silver Standard, and Quintana Minerals had each successively worked on the deposit. Consolidated Cinola Mines bought the claims in 1977 and completed exploration of the deposit ultimately in a joint venture arrangement with Energy Reserves. Energy Reserves entered in late 1979, and by 1983, a total of 200 surface and 12 underground drill holes had been completed, totaling 28 600 m (93,832 ft). In addition, a 461.9 m (1515 ft) adit was driven in the ore body. Reserves published by Cinola aggregate 34 Mt (37 million st) of 1.7 g (0.060 oz) Au per tonne. All industry geologists working in the area agree that the Queen Charlotte gold is an epithermal gold deposit in porous volcaniclastic and clastic rocks that is genetically related to a Miocene-Pliocene rhyolite plug. The geologic description here follows the oral presentation made by G. G. Richards, J. S. Christie, and M. R. Wolfhard at a 1976 CIM meeting. Additional comments by the late C. S. Ney of Kennco Explorations are included with the Richards, Christie, and Wolfhard data to complete the geologic set- ting. The attached reprint by Champigny and Sinclair (1 980) provides additional data on the deposit. The Queen Charlotte (Babe, Specogna, or Cinola) gold deposit is located on Graham Island in the northern Charlotte Islands, at the fault boundary of the Skidegate plateau and the Charlotte lowlands. The Sandspit fault marks the physiographic boundary, and it is intruded by rhyolite porphyry at the deposit. Because displaced geochem anomalies, drain- age patterns, and topography suggest dextral and east side down movement for the fault, exposed east block rocks are younger than rocks west of the fault. The east block, which included the ore deposit, is a lowland largely masked by unconsolidated Pleistocene and Recent clastic rocks. Rocks west of the rhyolite plug, on the Skidegate plateau, are Cretaceous carbonaceous and calcareous shale unconformably overlain by a thin veneer of rhyolite tuff. The deposit is about 100 m (328 ft) above sea level. GEOLOGIC SETTING At the ore deposit, the Sandspit fault is a complex structure. However, lithologies on either side of the fault-controlled rhyolite porphyry plug are distinct. West of the rhyolite, the upper member of the Cretaceous Haida formation shale is the most common rock type. The member is composed of dark grey to black, poorly consolidated, and thinly bedded carbonaceous and calcareous shale. The sequence is silicified to an argillite or a hornfels near the rhyolite. West of the rhyolite porphyry plug, but not importantly involved in the mineralization, is a thin masking cover of rhyolite tuff. The tuff unconformably succeeds the cretaceous shale, but it is largely eroded in the mine area. East of the fault-controlled rhyolite porphyry plug is a thick section of conglomerate and sandstone of the Miocene- Pliocene Skonun formation. The ore body occurs within the coarse clastics, the rhyolite intrusive as the western boundary. Ore is entirely contained within the clastics. Original permeability of the clastic rocks was a major control for ore deposition and alteration, and for that reason, the Skonun formation is described in greater detail. The Skonun formation clastics unconformably overlie Haida shale. The Skonun is at least 300 m (984 ft) thick in the mine area, where it trends northerly and dips easterly 15º to 25º. The sequence is about 62 percent conglomerate, 3 1 percent coarse arkosic sandstone, and 7 percent interbedded siltstone and sandstone. Contacts between adjacent beds are generally sharp. Stratigraphic correlations between drill

Jan 1, 1985