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By Tibor Horvath

Dust abatement is possible on bulk materials, whether conveyed or stockpiled. Minimum (ppm) quantities of chemical additives can efficiently and rapidly control dust of conveyed substrates with no effect on floatation chemistry. Top coating of large surface areas can control surface dust and wind erosion. Environmental and toxicity impact must be considered in any treatment, especially on areas with percolation runoff, leachates, or limited containment. The most effective dust control is preventing release of substrate fines rather than trapping and removing air borne dust. Techniques to prevent release of fines from conveyed substrates will be discussed. Dust control dynamics are a very complex combination of solid phase physical and chemical interactions between the substrate and the fines. ?Smart Technology? products permit dust abatement of stockpiled substrates and tailing fields with no environmental impact. Using ?Smart Technology?, the dust abatement products remain active and can re-seal damaged areas. Efficient, low environmental and toxicity impact, dust control will be demonstrated through case studies where these principals have been applied.

Oct 1, 2010

By Robert B. Parsons

"Several recent cases indicate that the Courts may be leaning toward a more favourable treatment of mine closing and related costs. In this article, we look at two recent cases, Burnco Industries Ltd. and Nomad Sand & Gravel Ltd. The former was heard before the Federal Court - Trial Division and the latter before the Tax Review Board.It appears that in certain situations mining companies may now be able to sustain current deductibility of estimated mine closing costs during the productive years of the mine, rather than waiting until either the date on which mining ceases or the reclamation and similar activities commence. This would be of great benefit to the mining industry, as waiting until the bitter end often means that there are no revenues available against which the expenses may be offset and, hence, no tax relief.IntroductionUnder the Income Tax Act in Canada, taxpayers are not permitted any deductions in respect of an outlay or expense in determining income from a business or property, except to the extent that such expenditures are made or incurred by the taxpayer for the purpose of gaining or producing income. In addition, no deductions are permitted for amounts transferred or credited to a reserve, contingent account or sinking fund except as expressly permitted by the Act.In large measure, these provisions are relevant to the mining industry to the extent that they determine the periods during which expenses may be charged against revenues for income tax purposes. Several recent cases have indicated that the Courts are leaning toward a more favourable treatment of accrued costs in the mining industry than was previously considered to be the case."

Jan 1, 1982

By G. W. H. Norman

"During the past few years emphasis has been placed on the importance of major faults, fault zones, and associated structures in localizing ore deposition. This interest has developed partly through experience in mining camps in other parts of the world, and partly by the discovery of such structures associated with ore deposits in the Abitibi region, northwestern Quebec. The recognition of these structures has been brought about chiefly by detailed mapping that has been gradually extended along most of the southern gold belt of Quebec and across adjacent parts of Ontario. In the Chibougamau region of northern Abitibi, progress has been made in mapping major faults by using aeroplane photographs with a scale of about 1,000 feet to 1 inch for field mapping. These studies have shown that many large faults occur in the Abitibi region; also that there is a relationship, direct or indirect, between faults and mineral deposition. The faults are, however, of more than one type and age, and this should be clearly appreciated in any planned programme for prospecting this great region adequately.Geology of the Abitibi RegionGeneral GeologyFaults of more than one age and type occur in the Abitibi region. In order to appreciate some of the age relationships of the faults, a brief summary of the historical aspects and major structural features of the geology (fig. 1) is necessary. These historical aspects may be briefly summarized in chronological order as follows:(1) Accumulation of Archæan lavas and associated pyroclastic rocks, either alternating with, or essentially followed by, deposition of sedimentary rocks, and interrupted at least once by local and perhaps regional folding and erosion."

Jan 1, 1954

By T. W. Bingay

The production of both lead and zinc in Canada has steadily increased during recent years until today Canada ranks among the world's leading producers of both of these metals. The high prices which they have commanded have led to an energetic search for new deposits and also to an investigation of abandoned properties which, under the present conditions of better prices and more efficient methods of treatment, offer chances of commercial success. It is confidently expected that during the next few years success in both these lines of activity will further increase Canada's lead and zinc output, giving her a still higher ranking among the world's producers. In 1926, approximately 140,000 tons of metallic lead was produced from ores mined in Canada, and of this, 125,000 tons was refined in Canada at Tadanac, B.C. During the same year the production of metallic zinc from Canadian ores amounted to 68,000 tons, of which 62,000 tons was refined at Tadanac. History Of Lead and Zinc in Canada The production of lead in Canada is much older than that of zinc. The chief source has always been the interior of British Columbia. As earl y as the 'eighteen twenties', Indians and Hudson's Bay Company's trappers had discovered an outcrop of lead ore on the site of the present Blue Bell mine on the east shore of Kootenay lake, but it was not until1865 that active prospecting for lode deposits began. In the early nineties the activity of the silver-lead-zinc region of the Slocan reached its culmination and a steady production has been maintained down to the present time. Up to the end of 1924 the Slocan area produced over 38 million ounces of silver, nearly 300 million pounds of lead, and almost 122 million pounds of zinc.

Jan 1, 1927

By K. Baris

Methane (CH4) present in coal seams, generally known as Coalbed Methane (CBM), Coal Mine Methane (CMM) or Coal Seam Gas (CSG), is a major energy source, as it is the primary constituent of natural gas. At the same time, released methane is a potent greenhouse gas (GHG) and a major safety hazard in underground mining operations. Therefore, a considerable effort has been undertaken to develop coal bed methane extraction and utilization technologies that can achieve both environmental and safety benefits. Countries with significant coal reserves and gassy seams, i.e., USA, Australia, Canada, China, India, Poland and Germany have developed mature methodologies and practices to extract, before and during mining, and utilize significant amounts of methane from coal seams. Nevertheless, on a global scale, methane recovery remains untested and many technical and economic challenges require urgent attention. The research presented in this paper, sponsored by the United States Environmental Protection Agency (EPA), is focused on the Zonguldak Basin, the only hard coal region in Turkey. The basin is known to contain very gassy coal seams and consists of three major regions: Armutcuk, Zonguldak and Amasra. Among the three, the Amasra coalfield is considered as the most favorable for CBM recovery, as it comprises of deeper coal seams and where a private company, Hema Enerji A.S. (Hema) is already developing coalbed methane production facilities. This study aims at developing a reservoir model to predict the potential CBM recovery from the CBM-2 well, the only producing CBM well drilled by HEMA Enerji A.S in the Amasra coalfield. History matching was utilized to model the 15-day production data and uncertainty analysis was performed to estimate the optimum values for the reservoir parameters. The produced model yielded an average production rate of 143 m3/day for 10 years. The total amount of CH4 to be produced during this period was 0.53 million m3. Furthermore, the total amount of GHG to be avoided was estimated at 6585 tCO2e.

Aug 1, 2013

By N. W. Xu, M. D. Wei, F. Dai, B. Li

"Chevron notched samples achieve general acceptance for measuring the Mode-I (opening mode) fracture toughness of rocks. The cracked chevron notched semi-circular bending (CCNSCB) sample, which is developed from the International Society of Rock Mechanics suggested the cracked chevron notched Brazilian disc method, has recently received much attention. However, these chevron notched methods have not been fully mastered, some ideal assumptions based by their theories and formulas, such as the straight-through crack assumption (STCA), have not been verified detailedly. Fractures of CCNSCB specimens were numerically simulated considering different heterogeneities, geometrical and mechanical parameters. The results show that, the real fractures of CCNSCB specimens are never satisfied with the STCA. In fact, micro fractures not only occur in the notch tip but also the two chevron edges. Consequently, the crack front features prominently in a shape of parabolic curve, far from being straightthrough. Moreover, curvature of the crack front is only affected by shape of the chevron ligament. Cracks usually start from two sides of the notch tips rather than center of the notch width, and propagate deviating from the postulated fracture routes. These fracture mechanisms induce errors with the measurements, and thus more attentions should be paid to the real fractures of the chevron notched samples for measuring fracture toughness more accurately. INTRODUCTIONWith the increasing requirement of people for resources and energies, frequent rock engineering activities have been conducting, such as underground excavation, oil exploration and deep burial of nuclear waste. Many problems appear in rock fracture. Consequently, there are more and more attentions paid in rock fracture mechanics due to its broad application prospects for solving these engineering problems. Since Mode-I (opening mode) fracture is the most common failure mode in rocks, Mode-I fracture toughness is a primary parameter to predict rock mechanical properties in actual engineering, and thus its accurate values are necessary to the researches of rockburst, rock mass slope stability, rock cutting, hydraulic fracturing, tunneling, et al. Therefore, it is thus significant to evaluate and study relevant methods to obtain the reliable value."

Jan 1, 2015

By M. H. ElMaghraby

This paper describes the development and validation of a strategy for vibration-based online detection of faults in a particular class of machinery commonly found in industry. This machinery is defined by two basic characteristics that preclude it from the application of standard online condition monitoring approaches. The first characteristic is that the machine is in a constant state of transient operation, thus making it difficult to differentiate between changes in transducer measurements that are due to variable duty and those that are due to machine malfunction or fault. The second characteristic is the fact that the machinery involves multiple sub systems that are subject to identical and simultaneous loading, operating environments and duty cycles. An example of such machinery is a system of multiple hydraulic pumps driving a common load. The monitoring strategy presented here employs an anomaly detection scheme together with methods of signal processing and feature extraction that exploit the parallel duty arrangements of this equipment. Preliminary data is collected from a pair or motor-gearbox assemblies used in a material haulage system in the mining industry. Testing and validation was performed on a mechatronic test bench with both healthy and faulted components. Experiments were carried out to investigate how various configurations of the system were able to detect different types of faults. The results indicate that this approach is effective and merits further investigation.

May 1, 2013

By D. R. Murray

"In 2017, Nutrien Allan Potash remediated a portion of the concrete liner in the production shaft. A set of underslung work platforms and collection boxes were used in conjunction with hydraulic splitters, jackleg drills and hand chippers to excavate and remove the broken concrete. New concrete was placed with the original pressure relief design, using a shaft slip form. Shortly after excavating, it was found that the estimated breaking rate and amount of original concrete in-situ was under estimated. Fifteen feet of excavated concrete (2719cu.ft) and ten feet (of replaced concrete was completed on April 28, 2017, and operation of the production shaft was returned to mine operations. During February 2019, Nutrien Allan Potash began remediation of a portion of the concrete liner in the service shaft. The project is different than the 2017 project, as the remediation has occurred during normal running operations and occurred only on night shift. Rather than hydraulic splitters and hand chippers, the new method includes a concrete saw and mechanical excavator from a working platform. The selected method is based on the lessons learned from the 2017 project in the production shaft. The service shaft project was scheduled to be completed in July, 2019. INTRODUCTION Nutrien Allan Potash is located approximated 75 km east of the city of Saskatoon, Saskatchewan, Canada. There are currently two shafts at Nutrien Allan Potash: the Production Shaft and the Service Shaft, transporting people and material from surface to a depth of 3,335 ft. The Production Shaft was completed in 1967, with one section of grey cast iron tubbing installed in the Blairmore formation between the 1605 and 2037 ft Levels. A second set of cast iron tubbing was installed in the Duperow formation between 2203 and 2463 ft Levels in 1999. The remainder of the concrete as of todays standards is designed as a pressure relief liner. The Service Shaft was completed in 1968, with one section of grey cast iron tubbing installed in the Blairmore formation between the 1600 and 2048 ft Levels. A second set of cast iron tubbing was installed in 1981, with 169 ft installed through the Duperow formation. The remainder of the concrete as of todays standards is designed as a pressure relief liner. PRODUCTION SHAFT REMEDIATION During the second quarter of 2015, the Mine Engineering team were notified of an area of concern in the production shaft. The shaft specialists of Golder Associates Ltd (Golder, formerly Alan Auld Canada) were contacted to complete an inspection of the production shaft liner with emphasis on the area of concern. Based on the inspection and documentation review, it was determined that the concrete at the 2804 foot elevation had been broken out for some time and was retained with #8 rebar bolts with resin encapsulation. The broken concrete was encroaching on the clearance to the conveyance."

Jan 1, 2019

By S. Feinstein, I. Reznik, Y. H. Hatzor, O. Shitrit, Y. O. Rosenberg, H. J. Vinegar, S. Nguyen

"We report the effects of porosity and total organic carbon (TOC) content on the mechanical behavior of organic-rich chalks, based on laboratory measurements. The organic-rich chalks are from the Senonian Ghareb and Mishash formations. This deposit is an immature oil-prone source rock, about 300 meters thick, situated at shallow depths (several hundreds of meters) in the Shefela basin in central Israel. The study is based on core data collected from the Zoharim borehole.Three main phases comprise the bulk volume of this rock: 1) carbonate mineralogical phase (predominantly calcite); 2) pores (mostly saturated with brine); and 3) solid organic phase (type IIS kerogen). The mechanical effects of porosity (23-45%) and TOC (4-19%) are evaluated based on bulk incompressibilities vs. volumetric fractions analysis. Volumetric fractions of mineralogical and organic phases were obtained by porosity, density and TOC measurements. Saturated rock bulk moduli were measured through ultrasonic velocity measurements. Saturated rock bulk moduli correlate best with the sum of kerogen and pore volume fractions, rather than each of them separately. The volumetric fractions were also used to define the range of bulk modulus of the organic-rich chalk, using the Hashin-Shtrikman upper and lower bounds. Based on Marion's Bounding Average Method (BAM), the normalized stiffness factor of the chalk averaged at w=0.197, indicating a soft pore geometry. Using the average normalized stiffness factor, the BAM predictions showed excellent match with the saturated rock bulk modulus and the sum of kerogen and pore volume fractions. Based on our findings, it is inferred that kerogen grains do not support the solid skeleton but are distributed between the minerals grains. We also propose here a straightforward approach for calculating the Hashin-Shtrikman bounds, based on TOC and porosity measurements. The mechanical effects of porosity and TOC indicated here are very important for the understanding of the influence of immature kerogen presence in highly porous chalks, as the Ghareb and Mishash formations."

Jan 1, 2015

By K. Östcrdahl

We are developing a cost-saving and environmentally friendly process with low energy consumption to recover the metal content and recycle the acid from spent pickle baths. The metals are precipitated as metal fluorides, which can be turned into metal oxides and hydrofluoric acid by thermal hydrolysis. In the proposed process the solution is concentrated by nanofiltration and the metals are precipitated in a subsequent crystallization step. Different nanofiltration membranes have been evaluated in experimental batch tests. The membrane MPF-34 from Koch Membrane Systems offered both good flux and acceptable metal retention even after long periods of acid storage. The solubility of B-FeF3.3H20 has been measured at varying acid concentrations and at different temperatures. The solubility decreases with increasing hydrofluoric acid and nitric acid concentrations. This suggests that the crystallization process should be operated at high acid concentrations. The crystal growth rate of B-FeF3.3H2O is found to be quite low but increases significantly with temperature. This suggests that the crystallization process should be operated at higher temperatures (40 - 60°C). Within the project a pilot plant has been constructed where the spent pickle bath solution is concentrated by nanofiltration to the desired metal fluoride supersaturation, and B-FeF3.3H2O is crystallized in a 10 L continuous crystallizer.

Jan 1, 2006

By M. Souley, G. Armand, M. Ghoreychi, D. Seyedi, J. -B. Kazmierczak

"An anisotropic constitutive model is proposed in this paper accounting for both structural anisotropy and induced anisotropic plasticity. It is assumed that the rock is composed of a matrix and of potential planes of weakness. The matrix is assumed to be linear, transversely isotropic and the plasticity is described by a non linear yield function where the parameters are deduced from the nonlinear Hoek-Brown envelopes in pre- and post-peak, and derived from the laboratory characterization. A non-associated flow rule is used with a distinction between compression and extensional stress paths, as well as the absence of volumetric strain beyond large plastic distortion.The planes of weakness are considered as known a priori or assumed to be oriented perpendicular to the direction of the current minor principal stress. An elastic-perfectly plastic behavior according to the Mohr-Coulomb criterion is assumed in the planes of weakness; while the elastic part is considered as linear and transversely isotropic.Finally, the proposed model was implemented in FLAC3D and used to simulate triaxial compressions to provide a verification of the implementation. The applicability of the implemented model to reproduce damage (pre-peak) and/or failure developments around a circular opening is checked. The GCS drift, one of the mine-by experiments set up at the main level of the Meuse/Haute-Marne Underground Research Laboratory, is selected for this first application."

Jan 1, 2015

By D. H. Ryan, B. Abdul, M. Pernechele, E. Asselin

Hydrometallurgical processing of sulphide concentrates at medium temperature (150°C) produces residues, which contain valuable metals (Cu, Ni) as well as sulphur and iron bearing minerals and phases. The low solubility of iron during the medium temperature processing of sulphide ores can favour the formation of poorly crystalline, nano-scale iron oxide/oxyhydroxide phases. A better understanding of the formation and structure of these iron precipitates may elucidate key factors that would ultimately result in lower valuable metal losses and more stable leach residues. Residues from two medium temperature leach processes were characterized by Mössbauer Spectroscopy. Some portions of the Mössbauer Spectrum were suspected to be linked to jarosite but could not be positively identified as such. There was a broad range of disorder and substitution present in the material and solely attributing it to jarosite proved difficult. Various synthetic jarosites with Cu substitution were precipitated for Mössbauer analysis. These were then characterized by Quantitative X-Ray Diffraction (QXRD), Scanning Electron Microscopy (SEM), Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) and Mössbauer Spectroscopy. The Mössbauer Spectra of the synthetic jarosites is compared with that of the residues from medium temperature (150°C) sulphide concentrate leaching.

Jan 1, 2014

By James H. C. Martens

Among the many interesting problems of the pre-Cambrian of the Canadian Shield is that of the origin of certain types of gneisses which are intimately associated with the granites on the one hand and with the metamorphic rocks of known sedimentary origin on the other. The observations recorded in this paper on the structure and composition of these ancient rocks found in a small part of northern Quebec may help to lead to a clearer understanding of the way in which they were formed and also constitute a contribution to the regional geology and petrography of a district for which little detailed information is available. The area considered is located near the Ashuapmuchuan, or Chamuchuan, river about 180 miles north-northwest of the city of Quebec, and therefore well within the Canadian Shield. Although most attention was devoted to the rocks along this river from the 57th to the 70th mile above its entrance into Lake St. John, a few observations on other localities to the north and northwest of that lake will be included. The field work was done in the summer of 1924 in cooperation with L. W. MacNaughton, E. S. Roberts, and B. M. Shaub, all of Cornell University. The party ascended the Ashuapmuchuan river by canoe and spent about a month near the mouth of Stacker, or Brochet, river, the outlet of the lake of the same name, returning by way of Mikoasas river. The writer wishes to express his obligation to his associates for their co-operation in the field and for their permission to publish the results. He is especially indebted to B. M. Shaub for the photographs of rock outcrops. Professor A. C. Gill g:ive many suggestions which were helpful in the laboratory study of specimens and in the preparation of this paper.

Jan 1, 1927

By M. Kreuh

An investigation of the pressure pulse spectrum generated by the gas dispersion processes in a Peirce Smith copper converter was undertaken via the simultaneous measurement of four tuyeres using high frequency pressure transducers. The data was captured, stored, and analyzed using digital data processing techniques; including power spectral density plots, band-pass filtering, and a principal component analysis (PCA). The process was characterized throughout by a dominant 3 Hz pulse signature attributed to the formation of lateral gas envelopes. In particular, test tuyeres in the tuyere line tended to operate synchronously at the dominant frequency, regardless of operating conditions tested and despite being distributed along the converter. Synchronous behavior is thought to arise from the acoustic coupling and possible resonance behavior of the gas delivery system on the converter.

Jan 1, 2007

The dynamic breakage process of rocks by the impact of a hydraulic hammer is more complex than one normally assumes. It is even more difficult when one has to conduct the breakage under water. In such cases one does not know exactly what the surface topography and composition are at the bottom of the sea or river and, hence, it is more difficult to select the best position of the hammer before starting the hammering. Typically, an industrial hammer has a diameter of about 250 mm, a length of about 1.25 to 1.75 m and a mass of several tons. The hammer frequency can be up to 50 impacts per minute. The general principles of rock hammering can be easily summarized, but this knowledge is not sufficient to adapt adequately the method for less common rock conditions (e.g. less brittle rock, presence of vertical and subvertical fractures, etc.). That is the reason why we initiated a research project, whereby a scale model has been developed to conduct experiments in the laboratory and whereby discrete element simulations are being conducted. Both aim at a better understanding of the basic mechanisms of rock hammering. The scaled experimental model allows varying the impact energy and the static weight independently. Within the experiment, the hammer is in contact with the rock specimen under a certain confining pressure and with a certain contact pressure due to the static weight. A weight falls on the hammer, creating the dynamic action or impact; the height over which the weight falls can be varied. The penetration is recorded after each impact. After a certain penetration the test is stopped and the internal crack patterns are described. Some simulations have been conducted, allowing the modeling of individual fracture initiation and growth during the penetration of the hammer by either a constant displacement rate (using the UDEC-code) or by introducing the dynamic process (using the PFC-code). Some of the observed features in the laboratory experiments can be visualized in the simulations. However, further research is needed to allow the simulations being an adequate tool to well understand the dynamic process in laboratory experiments, as well as the in-situ behavior.

Aug 1, 2013

By F. Chevarin

The reaction of O2 with the carbon anode is considered as the main parasitic chemical reaction affecting Hall-Heroult process anodes. The current study aims at investigating the influence of the microstructure of baked anode on its overconsumption. Samples were removed from different positions of an industrial anode. Density, porosity, Lc and BET specific surface area were measured. The anode reactivity was evaluated based on the weight losses for the samples resulting from the reaction of anode with air at 550°C after 7h. The essential parameters determined to control the air reactivity are closed porosity, Lc and pores with a pore entrance radius of 1.5, 8.5 and 12 p.m. The knowledge of effects of these parameters allows better understanding of the reactivity of anodes and consequently reduction of their overconsumption in electrolysis bath.

Jan 1, 2011

By M. Redfearn

"DUST COLLECTION EQUIPMENT LIST Primary Dust CollectorModular Mikro-Pulsaire - Model 2G1-96TR Capacity: 20,000 c.f.m.Bags: Total of 288; 8' x 4 1/2"" diameterMaterial: Dacron HCE feltAir to cloth ratio: 7.55/1Bags are changed every 6-9 months. Sent to A & L Services for cleaning at a cost of less than 1/3 the price of a new bag. No new bags have been required since start-up 4 years ago.Blow hack: 35 c.f.m. at 100 p.s.i.Fan: Joy Manufacturing, Model 3300, Type 4S, Backward inclined fan.Impeller: 33"" diameter36"" diameter Inlet33"" diameter Outlet at 3200 f.p.m. velocity1945Motor:,60 H.P., 1780 r.p.m.Capacity: 23,400 c.f.m.Design:,20,000 c.f.m.,•Actual:,17,500-19,000 c.f.m. depending on bag condition.Dust Slurry Agitator: Port-a-flo Model 050-350Major Maintenance:The fan was sped up from 1830 to 1945 r.p.m. and balanced at the higher speed. Several months later the impeller destructed beyond repair. A new shaft and impeller was installed, casings straightened, and bearings reused. Unit is currently running at 1945 r.p.m. No definite cause for the impeller failure has been found, although it might be attributed to improper balancing."

Jan 1, 1976

By W. Dziurzynski, St. Wasilewski, T. Palka, A. Krach

"Air parameter monitoring systems, regardless of gasometrical protections, provide a significant number of measurement data. The obtained data broadens the knowledge on processes taking place in underground workings and shows the relationships and influence of machines and technological processes on the variability of ventilation parameters in the areas of longwalls. Nowadays, computer simulation methods are increasingly used to reproduce the flow of air and methane mixture in the area of longwalls equipped with shearers. The paper presents the results of a research experiment covering a long-term observation of a longwall area during mining with a shearer using sensors from the mine's monitoring system. Data from sensors for methane concentration, pressure and velocity were used and additional ventilation measurements were taken to determine the parameters characterising the air flow in the area. The influence of different machine cycles in the longwall on the changes of air parameters in the area of the longwall was shown. A numerical model of the ventilation area was developed and the computer program VentZroby was used for the calculations, which allows for the simulation of the process of ventilating the area of the active longwall during the extraction of coal with the use of a shearer and haulage of the run-of-mine. Computer simulation of the influence of the shearer's operation and the methane inflow associated with the distribution of the mixture of air and methane was carried out. The results of the simulation were compared with the data recorded by the monitoring system’s sensors during the measurement experiment. Comparison of the recorded methane concentration courses with the results of a computer simulation of the air and methane flow conditions in the mining area showed changes in the gassiness. INTRODUCTION Studies carried out in the Polish and global mining industry show that methane is an obvious factor in limiting mining production due to the loss of continuity in the operation of longwall complexes in hard coal mines under methane emission hazard (Schatzel et al., 2008). In addition, methane hazards have a significant impact on the safety of the operators of machinery in the longwall. The requirements of Polish regulations and the practice of safe operation of mining longwalls require correct determination of gas concentration, volume flow, as well as pressure and temperature of the flowing air. As part of the research undertaken in the Budryk (Wasilewski, 2010) and Bielszowice (Dziurzynski et al., 2009) mines to assess the methane hazard in the longwalls and workings in the vicinity of the longwall, research experiments were carried out, during which air parameters were recorded by the mine monitoring system and additional testing equipment in different cycles of shearer operation."

Jan 1, 2019

By V. ?. Chanturiya, G. P. Dvoychenkova, ?. Ye. Kovalchuk

"Several mineralogical investigations have revealed the composition of modified kimberlites and the mud generated during treatment of diamonds, which contains up to 50% clay minerals (e.g., talc, talcsaponite, chlorite-saponite, Na-saponite) and X-ray amorphous phase. We investigated the composition of the natural diamond surface in relation to the diagnosed minerals and established the sequence and conditions for mineral formation on the crystal surface under kimberlite processing conditions. This article suggests a method to destroy and further dissolve minerals on the crystal surfaces using water system electrolysis products, which makes it possible to restore the diamond hydrophobic properties. The application of chemically treated water in the foam separation cycle under the conditions of high recovery of diamonds made it possible to increase the content of the factory concentrate by 8.0%.INTRODUCTIONThe high content of the modified minerals in the kimberlite ore results in the formation of hydrophilic slicks on the surface of the crystals which decreases the diamond’s hydrophobic properties and increases the losses thereof in the process of grease and foam separation to 20-30% (Kurenkov, 1957; Chanturiya et al., 1998, 1999, 2005; Duikarev et al., 2000).The previous researches have revealed the fact that the prospective way of solving the problem of intensity of mineral impurities formation on the surface of the crystals and the increase of concentration parameters is reached due to application of physical and chemical stimulation techniques on the solid and liquid pulp (Stricland-Constable, 1971; “Improvement of the technology…”, 2006; Makarskii, Adodin & Tarasova, 2011; Chanturiya, Dvoychenkova & Trofimova, 2012). However, the main task of investigations to stipulate the objective achievement is the studying and justification of the reasons of the diamond surfaces covering by the mineral slicks"

Jan 1, 2016

By D. M. Baird

Copper mineralization occurs at several places along the shore of Notre Dame bay, Newfoundland, and at one time formed the basis of a considerable mining industry. The sources of the mineralizing solutions and the structural settings of some of the deposits have not been clearly understood. This paper reports new investigations into the origin and structure of the deposits between Bett's cove and Stocking harbour, in a strip about ten miles long and two miles wide along the western shore of Notre Dame bay. The most complete previous descriptions of the area are those of Snelgrove (1929, 1931, 1938), Douglas, Williams and Rove (1940), and the writer (1947). The discovery of the Bett's Cove deposits took place about 1860, soon after the discovery of the well-known Tilt Cove deposits to the north. Several other small prospects were found between Bett's cove and Stocking harbour between 1880 and 1910. At Bett's cove, active mining began in 1875 and a small smelting plant was built near the mine in 1877. .Mining operations came to an abrupt halt in 1883 after a major cave-in. In 1900, and again in 1906, attempts were made to drain the old workings and reopen the mine but were abandoned long before completion. Total production amounted to about 130,000 tons of hand-picked copper ore which averaged about ten per cent copper, and 2,450 tons of pyrite (Snelgrove, 1938, pp. 52-55).

Jan 1, 1948