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By Michael J. Beus

The National Institute of Occupational Safety and Health-Spokane Research Laboratory (NIOSH-SRL) have developed a Shaft Conveyance Monitoring System (SCMS). Assessment of current hoisting technology has shown that monitoring wire rope tension and conveyance position and load directly from the skip or cage top offers several significant safety, production, and maintenance advantages. The SCMS consists of conveyance position and guide displacement sensors, a battery power supply and charging system, and a new sensor to measure hoist rope tension. This device provides a warning of the occurrence of ?slack rope? a particularly dangerous condition. A 2.4 GHz radio link transmits data to the hoistroom. A reduced scale hoisting test facility has been constructed to test these components prior to field trials. The advantages of monitoring wire rope tension and conveyance position and load directly from a skip or cage top will be discussed. Field tests are underway in full-size shafts to refine the concept and evaluate long-term reliability and maintenance requirements. Application of this technology may result in decreased maintenance costs as well as safer, more productive hoisting operations.

May 1, 2001

By Wael Abdellah

Mine haulage drifts are the primary access to the mining blocks of an orebody in a multilevel mining system of a tabular ore deposit. The stability and functionality of haulage drifts are thus crucial to the success of a mining operation. Drift instability could lead to serious consequences such as injuries, production delays and higher operational cost. In this paper, the performance of the haulage drift stability is evaluated on the basis of the primary rock support system comprising 1.8 m resin grouted rebars in the drift walls and 2.1 m long bolt in the back. Two failure criteria namely the extent of Mohr-Coulomb yield zones around the drift, and linear elastic brittle shear failure are adopted and compared, with respect to lower level and same-level mining and filling sequence in the vicinity of the haulage drift. The case study is one of the #1 Shear East zone of the Garson Mine in Sudbury, Ontario. Random Monte Carlo (RMC) technique, which has been previously established to assess the haulage drift stability, is employed in this investigation. The RMC technique is used in conjunction with finite difference modelling software FLAC for random assignment of model input parameters in the FLAC grid. Deterministic model results reveal the drift behaviour in terms of deformation (convergence) and mining-induced stress distribution. Comparison between the two different criteria is carried out to determine which method is most suitable in evaluating unsatisfactory drift performance. The results are presented in terms of probability of instability and categorized with respect to failure condition and mining step. It is shown that the brittle shear failure condition based on linear elastic response calls for enhanced support system at a later mining step than what Mohr- Coulomb yielding condition does. The paper presents a detailed discussion of the stochastic analysis results.

Jun 1, 2012

By B. R. Rakishev

When transferring from the railway transport to the combined automobile-conveyor transport by stripping works at coal mines, it was proposed to form at the working zone a concentration horizon for reloading part of the stripping volumes at the railway transport. The procedure is adduced for substantiating parameters of bloc-panels, depending on the step of transferring of reloading points in interrelation with the intensity of the working zone?s development with observing the balanced movement of parts of the stripping zone relative to the temporary concentration level.

Aug 1, 2013

By Erik C. Westman

Knowledge of the orientation and relative magnitude of in-situ stresses at the mine scale is important for safe and efficient production from an underground mine. With this knowledge, stope location and scheduling can be optimized. Passive seismic tomography was used for imaging horizontal stress distribution at the mine scale. Microseismic measurements from the Creighton mine were used as input for the tomography calculations. The double-difference tomography algorithm was used, which provides the most precise results. The results clearly show a low velocity zone in the previously mined areas bounded by two high-velocity lobes located adjacent to the mined openings at locations consistent with those expected due to the horizontal stresses at the mine. The overarching goal of the research is to provide a tool that can augment both numerical modeling results and underground geotechnical measurements to allow the mine operator to produce in the safest and most efficient manner possible.

Jun 1, 2012

By John Wightman

LOCATION OF PROPERTY THE property of Caribou Gold Mines, Limited, is situated in the north-eastern part of Halifax county, seven miles south of the Canadian National railway line at Upper Musquodoboit. Approach to the village is by a secondary road, improved recently by waste rock from the mine dump. A two-wire telephone line, seven miles long, built and owned by the present operators, provides communication to the nearest telephone exchange, Parker's Corner. HISTORY In 1870, the Caribou area was recognized as a proclaimed gold district. From then on, operations were intermittent, with periods of considerable activity by small companies until there were no fewer than seven mines in a district two miles long by three-quarters of a mile wide. These were the Holman, Truro, Caffrey, MacDonald or Elk, Lake, Dixon, and Hilchey properties, all of which have had separate stamp-mills, and have produced gold for varying periods. Depths of the workings range from 100 feet to 1,000 feet. Power was generated at each property by means of steam boilers. At the present time, the Consolidated Mining and Smelting Company of Canada, Limited, controls all the leased areas, approximately 800 acres, and is operating by means of one central vertical shaft. GEOLOGY The district in and about Caribou Mines has an elevation of approximately five hundred feet above sea level. The area is fairly well wooded, with rock outcrops here and there. These outcrops, along with information from test-pits and shafts, have been the basis for the very excellent geological map of the district prepared by E. R. Faribault some years ago. The rock structure, which is one of the best examples in Nova Scotia of an elliptical dome, has its anticlinal axis in a northeast-southwest direction, and flat plunges in the same directions.

Jan 1, 1938

By X. T. Feng, Y. H. Hatzor, Y. Tal, G. Yagoda-Biran

"When studying jointed rock mass deformation around underground openings it is of great importance to model correctly the excavation sequence during the numerical simulation. This is because for effective arching mechanism to develop in the roof minute block displacements must take place and some of the available discontinuities shear strength must be mobilized. If from the beginning of the simulation the underground opening already exists in the numerical model, block displacements into the excavation space will initiate and develop from time zero, before the initial stresses in the model have attained their actual initial level in the field. These initial block displacements are therefore artificial and exist only in the numerical model, not in the physical reality, and may lead to erroneous assessment of the stability of the designed structure, typically on the conservative side. We have introduced sequence excavation capabilities both in the numerical manifold (NMM) and the discontinuous deformation analysis (DDA) methods and show here the advantages of this modification using three different case studies, each illuminating a different aspect of this enhancement.We begin with the 25 meter deep 2000 year old underground Zedekiah limestone quarry below the old city of Jerusalem, Israel, which is still standing today unsupported with a free span of 40 m. We show that when the opening exists from the beginning of the numerical simulation the required friction angle for roof stability is 25 degrees, whereas when the opening is removed after all stresses and displacements in the model have been stabilized the required friction angle for stability is only 15 degrees.We then model the excavation sequence of a tunnel model representing a 2500 meter deep research tunnel in the Jinping hydroelectric project, China, in order to determine the in situ stress field at this depth by a grid search inversion of displacement data obtained using the sliding micrometer technology in the course of tunnel excavation. Thus we are able to constrain the in situ stress field at these depths where standard in situ stress measurement procedures are extremely difficult to execute properly.Finally, we use sequence excavation modeling capability to find the total height of the expected loosening zone around tunnels excavated through columnar jointed basalts which pose a great engineering challenge because of the characteristic dense network of slender prismatic blocks that transect the opening at a steep inclination. We use MPBX data obtained during excavation of a deep tunnel through such a rock mass to validate our numerical results and show that application of standard empirical guidelines for dimensioning rock bolt reinforcement in such rock masses may in fact result in very un-conservative design because existing empirical approaches typically ignore the anisotropic nature of the structure of such rock masses which, as we show, plays a very significant role in determination of the extent, shape, and geometry of the loosening zone around the opening."

Jan 1, 2015

By J. P. Jylhä, A. Jokilaakso

The Outotec Flash Smelting process is widely used in primary copper production. A layer of slag on top of matte (copper–iron sulphide melt) creates a barrier through which matte droplets descend. Droplets of different sizes settle through the layer at different rates, which increases possibility of copper losses as smaller matte droplets may be removed with the slag. In this work CFD-DEM (computational fluid dynamics – discrete element method) coupling was used to simulate matte droplets settling through the slag during slag tapping. Discrete droplets and slag flow were simulated with DEM and CFD, respectively. This new approach enables tracking and solving movement and interactions of individual droplets. User-defined models were created to take coalescence and reaction kinetics into account. Coalescence created larger droplets, while the reactions decreased droplet size and increased its density. Drag caused funnelling effect, which pulled droplets towards the centre line of the descending cluster. This research is the only study known by the present authors in modelling liquid-liquid systems with the CFD-DEM coupling. Simulating coalescence and chemical reactions for discrete droplets enables more realistic simulations. However, CFD- DEM simulations are computationally resource intensive already without additional models, so a full scale industrial settler modelling still waits for further increase in computer performance. INTRODUCTION Flash smelting is a method used in copper and nickel production. In the flash smelting process, oxidation of sulphides in a concentrate is used to release energy needed to smelt the feed. In the process, copper matte is formed. Matte has copper content in the range of 55 – 70% (Sridhar, Toguri, & Simeonov, 1997), the rest is mainly sulphur and iron but has still many other impurities (Taskinen, Seppälä, Laulumaa, & Poijärvi, 2001). Oxidized iron forms iron-silicate slag while SO2 is collected for acid production (Davenport & Partelpoeg, 2015). The Outotec flash smelting furnace (FSF) can be divided in four major component: concentrate burner, reaction shaft, settler and uptake. Concentrate, flux and oxygen enriched air are injected into the reactor through the concentrate burner. The mixture then reacts in the reaction shaft forming matte and slag, which are collected in the settler, while off-gases flow out of the reactor through uptake for heat and dust recovery, and SO2 collection for H2SO4 production. The matte and slag form separate layers due to immiscibility and density difference. Raw material feed is continuous, but the matte and the slag are tapped periodically. A flash smelting furnace is depicted in Figure 1.

Jan 1, 2019

By S. Litke

Elemental sulfur was stockpiled at the Mount Polley Mine for use as a source of sulfuric acid as part of research into leaching copper from oxide ores, but the project did not proceed beyond an initial pilot- scale evaluation. Since placement, the sulfur has oxidized and some sulfuric acid leached into the underlying rock. The reaction of the acid with these underlying materials has been studied as part of an evaluation of the effects of leachate from the pile. The rock underneath the sulfur pile is composed dominantly of primary and secondary alumino-silicates with less than 1% carbonate (calcite) and iron sulfide (pyrite). In its unaltered condition, the rock is classified as non-acid generating. Conceptually, it was expected the sulfuric acid would be neutralized by the rock to varying degrees resulting in a series of pH-controlled weathering fronts progressing from leached near the contact with the sulfur pile (pH <3), to active neutralization by silicates (pH 4–5), to active neutralization by carbonates (pH >7). The rocks underneath the pile were sampled to determine the extent to which the rocks had reacted and their long-term stability after removal of the acid source. INTRODUCTION When rock is blasted and excavated to facilitate mining ore, it is typically placed and stored on the surface in piles. The resulting drainage may have a neutral to basic pH (i.e., non-acidic drainage) or a low pH (i.e., acid rock drainage, ARD) depending on the mineralogy of the rock being stored in the piles. Acid- base accounting (ABA) can be used to characterise the two types of rock: potentially acidic drainage generating (PAG) and not potentially acidic drainage generating (NAG) (Price, 2009). According to Price (2009), NAG is defined as having an excess of neutralization potential (NP) in the rock in the form of calcium carbonate-like minerals when compared to acid potential (AP), i.e., a Neutralization Potential Ratio (NP/AP = NPR) greater than 2.0, whereas PAG is classified as having an excess of AP (i.e., an NPR less than 1.0). This is a conservative estimate and may be slightly modified depending on the mineralogy at specific mine sites. Rock with an NPR of 1–2 is also capable of generating acid (Price, 2009) and, depending on the mineralogy, may also be classified as PAG. Drainage from PAG material can generate acid immediately, or many years after it has been exposed to surface conditions. Disposal techniques depend on the category (i.e., NAG or PAG) and reactivity of the rock stored in the piles.

Jan 1, 2019

By Chuan-Jian Zhong

Gold-based nanoparticles in the size range of a few nm have attracted increasing interests in catalysis, sensors and biomedical applications. The study of the unique catalytic properties of nanosized gold was inspired by the pioneering work of Haruta on the nanogold-catalyzed CO oxidation (1-4). There have been a number of excellent reports discussing both fundamental and application aspects of gold nanoparticles in catalysis (3-8). Our work reported herein is aimed at investigating the preparation and application of gold and its alloy nanoparticles for potential applications in fuel cell catalysis. Fuel cells operating by electrochemical oxidation of hydrogen or methanol fuels at the anode and reduction of oxygen at the cathode are attractive power sources due to their high conversion efficiencies, low pollution, lightweight and high power density. While methanol offers the advantage of easy storage and transportation in comparison with hydrogen fuel cell, its energy density (~2000 Wh/kg) and operating cell voltage (0.4 V) are much lower than the theoretical energy density (~6000 Wh/kg) and the thermodynamic potential (~1.2 V). The poor activity of the anode catalysts and inefficient activity or issue related to "methanol cross-over" at the cathode electrode are associated with the loss of about one-third of the available energy at the cathode and the other one-third at the anode. Extensive studies have been focused on Pt-group metals (Pt+Pd+Rh+Ru+Ir (PGM)) for both anode and cathode catalysts. A major problem is the poisoning of Pt by COlike intermediate species (9,10). Recently, oxide-supported gold nanoparticles in the <10 nm size range have emerged as one of the best catalysts for CO oxidation (1-3,11), and for water gas shift reaction in reforming stage using 5 nm Au on Fe2O3 (6). Gold and its alloy with other metals in the nanosize range present new alternatives (2,12). Whether the unique properties of gold nanoparticles can be exploited for addressing these problems is a focus area of our work. The ability to harness the large surface area-to-volume ratios and the unique surface sites of nanoparticles in <10 nm size range, especially in heterogeneous catalysis, constitutes a major driving force in fundamental research and practical applications of nanoparticle catalysts. It is this size range over which the metal particles undergo a transition from atomic to metallic properties. The understanding of factors controlling the morphological and surface reconstitution associated with such a size range is of fundamental importance to the ultimate exploration of nanostructured catalysts. We have been investigating the interfacial structures and properties of core-shell types of nanoparticles consisting of gold or alloy nanocrystal cores and organic monolayer shells that were prepared by twophase synthesis (13) and processing (14) protocols. Important attributes of such nanoparticles include controllable size monodispersity, processibility, and stability towards size- and composition-tunable catalysis (15-21). Some of these attributes were studied for understanding their electrocatalytic properties in the oxidation of methanol and reduction of oxygen, which are of fundamental interest to fuel cell technology.

Oct 1, 2003

By Geo. E. Cole

A GREAT deal of time and energy is now being devoted to the study of post-war reconstruction and rehabilitation, in spite of the fact that as yet we have not won the war in which we are presently engaged. If you feel that the study of post-war problems takes our thought away from the problem immediately before us, you may well query, "Well! What has all that to do with winning the war, our most urgent problem today?" The answer has been given by Principal James of McGill University, Chairman of the Cabinet Committee on Reconstruction: "Reconstruction is something which must be thought of in advance, partly for the purpose of recognizing exactly the influence of war-time activities, controls, and regulations on the post-war Canadian scene. Many people are acutely interested in this great problem. It is not that they are not interested in the war itself, or epochal events that are taking place from day to day. They have a vision of that future which they hope will be Canada&apos;s, and this vision inspires them to even greater efforts at the present time". The trend of events would indicate that changes, economic and industrial, after this war will be greatly out of line with those that followed previous wars in history, for the present struggle has involved every nation in the world. In the peace that will come, every engineer will have a task in bringing the most desirable order out of the most distressing chaos. We certainly are living in a changing world; we are witnessing geo-graphical and economic readjustments that no other generation in world&apos;s history has ever witnessed. And there is an opinion gaining strength in our Dominion, as in other lands, that after this war we shall live in a world in which our process of thinking and our very way of life will have to undergo drastic changes to cope with the new order of things. Sadly our world of today has had to revise the sublime vision that nation shall not lift up sword against nation, while salvage operations continue to beat ploughshares into tanks and the peaceful pruning-hook into a weapon for the deviltry of the commando.

Jan 1, 1943

By P. Cleyle, J. H. Masliyah, R. S. Chow, Z. H. Xu, Z. A. Zhou

Bubble nucleation in water under dynamic conditions was investigated using an autoclave at an air saturation pressure of 7 atm. Agitation during air saturation of water was found to be crucial in enhancing tiny bubble formation. More bubbles nucleated on hydrophobic surfaces at a higher agitation rate, due to cavity formation by the more intense hydrodynamic conditions. Flotation recovery of bitumen from oil sands demonstrated a significant role of bubbles nucleated in water: more than 50-170% increase in bitumen recovery from different oil sands was obtained by using air supersaturated than the regular water.

Jan 1, 2009

By Yongquan Zhu, Zhengguo Zhu, Zhichun Liu, Chao Kong, Xinqiang Gao

"The aim of the study is to have a good understanding of the change in the seepage field during and after the tunnel excavation in weathering alteration rock. Field tests are used to monitor the changes of the water table and the numerical model is used to analysis the influence of the seepage filed with different operation conditions during and after the tunnel excavation. Results indicate that the depth, diameter and pumpage of precipitation well are the main factors that have a great influence on the drainage effect. Results also indicate that different operation conditions had various effects on the decrease in water yield during tunnel construction and the recovery in groundwater level after construction.INTRODUCTIONAs a potential disease during tunnel construction, Gushing water not only affected construction schedule, increased construction cost, as well as affected tunnel stability and safety during operation, but also decreased ground-water level. What’s more, the fall of water table caused by gushing water in tunnel would have influenced surrounding residents’ living water, agricultural water and ecological environment around tunnel. In recent years, enough emphasis has been paid to the influence on environment due to the construction of tunnel as a result of the reinforcement of people’s environmental protection awareness.As a result of water collection and drainage after excavation, groundwater was discharged into the tunnel, which caused a loss of water resources in the adjacent mountain mass. Furthermore, during tunnel operation, it was difficult for groundwater level to resume its original condition, which caused a bad ecological environment, because drainage system during tunnel construction destroyed its original hydrologic dynamic balance.In order to study whether decreased groundwater level resulting from tunnel construction could be restored during operation to its original condition, this paper gave a field monitoring on tunnel displacement during construction and simultaneously, generalized model of regional hydrogeology was created according to field hydrogeology to carry out a calculation of stable seepage flow and draw comparisons between recovery conditions of various water levels."

Jan 1, 2015

By Alexander Smith

"The Silver Standard mine is 6 miles by road northwest of New Hazelton, B.C., a small town on the northern line of the Canadian National Railways some l 75 miles northeast of Prince Rupert. The deposits lie on the western slope of Glen Mountain (elevation 2,100 feet), with the main adit, mill, and campsite at 1,300 feet. The deposits were found in 1910, shortly after the area had been swept by forest fire and during a period of prospecting activity spurred by the construction of the railway. Crude ore only was shipped until 1918, when a 50-ton gravity mill was built which operated until 1922. Gross value of production of this period, at present metal prices, was about $1,000,000.In 1947 the present company was formed and a 50-ton flotation mill installed. Production from 1948 to 1955 has been in excess of $10,000,000, and net smelter returns about two-thirds of this amount. More than 60 per cent of the production and 80 per cent of the profit have come from one vein, No. 6. On the 1,300-foot level this vein had an ore section 375 feet long and 2.5 feet wide, averaging 0.18 ounces gold, 85 ounces silver, 10 per cent lead, and 16 per cent zinc.The mine workings follow a simple pattern. A series of parallel veins, striking northeast and dipping southeast, are numbered from 0 to 12, starting at the northwest. They lie within a zone trending south 70 degrees east, and the distance between Nos. 0 and 12 veins is about one mile. Recently several cross-veins, dipping northeast, have been found between Nos. 8 and 12. They are apparently of the same type as the others, though they may not have the same structural controls. They could be an important new source of ore.The mine has been developed principally by crosscut adits at the 1,500- and 1,300-foot levels and a 510-foot shaft with levels at I, 150, 1,000, ·and 850 feet. Drifts and crosscuts total 17,000 feet, chiefly on Nos. I, 4, 6, 7, and 8 veins. The drifts are stoped by shrinkage, top shrinkage rill, cut-and-fill with resuing, or open stope methods. The mill produces a lead-silver-gold-copper concentrate and a zinc concentrate, with indicated recovery of more than 96 per cent (4)."

Jan 1, 1949

By M. Mirzazadeh

Air cooled crackable and conventional forged steel specimens were tested under reversed push-pull conditions to examine the effect of shot-peening on their high cycle fatigue behaviour (-106 cycles). The steels were tested in the normalized as well as shot-peened conditions. The results showed that shot-peening smooth specimens had little effect on the fatigue limit of the air cooled forged steels and the detrimental effect of the rougher peened surface was not apparent. Microhardness profiles indicated that the shot peening produced a gradient of compressive residual stresses that was greater than that of the loading stresses, suppressing the anticipated beneficial effect on fatigue life. Crack initiation was more likely to occur below the surface. The results indicate that the surface roughness was not a significant factor in controlling the fatigue lives, since they were essentially the same for the non shot-peened and shot-peened steels.

Jan 1, 2010

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 G. G. Bowser

THE time has come when, as your President, 1 turn the helm over to my worthy successor. When 1 was reminded by our Secretary that 1 had to prepare an address for this meeting, 1 was at a loss for a subject. In the hope of inspiration 1 perused the records of our Society for some years past. 1 found in these records that many problems in need of solution relative to industry in Nova Scotia were discursively dealt with and that sound thought was given to the solution of these problems, with a natural leaning, of course, to problems pertaining to the mining industry. 1 found also that some of the reasoning was remarkably prophetie. Some of these subjects and problems were: The use of pulverized coal to generate power instead of hydro-electric power; rural electrification; the importance of youth training for an efficient place in industry; the proper marketing of coal; the fuels competing with coal; the need for better in-dustrial relations between employer and employee; better education for success in the social field as applied to industry; and Canadian unity. The issue of some of these copies has been forced upon us by war. For instance, there appears to be no marketing problem for coal, nor does there ? seem to be a marketing problem for anything just at present. The problem of the coal producer just now is supply and transportation. Also, at present, coal fe.ars no competitors, such as oil-and not even hardwood. Many large companies now have an industrial Relations or Personnel Manager and department. Furthermore, we have been compelled of necessity to train our young men, and women also, for both industry and war. However, war does not solve these problems and, with the return to normal times, we may be faced with the same troubles in even greater measure. My reason for mentioning these copies is to point out that, as mining men, we are aU desirous of progress in every industry, not only the mining industry; and that mining men are able to see clearly ahead. In normal times, especially in matters not directly affecting the mining industry, we are inclined to let matters take their own good rime, or let the government do it. We do not seem to realize that these necessary and desirable changes can be made in times of peace-instead of being forced upon us by war or other social upheavals-by the method of sound thought and action to the desired end.

Jan 1, 1943

By R. F. Neider, W. R. Bain

"Expanding upon one aspect of a recent paper on ""Fluid Column Roasting at Sherbrooke Metallurgical Co. Ltd.,"" the present paper deals with the operation of the fluid column process to achieve substantial elimination of cadmium and lead during the roasting of pelletized zinc concentrates. Designed to meet the need for additional feed for Matthiessen and Regeler Zinc Company's vertical retort zinc smelter in West Virginia, without recourse to a sintering operation, the plant is capable of simultaneously attaining very low lead and cadmium levels on demand, through operation in the manner described. Fluidizing air admitted via the wind box is supplemented by natural gas admitted via a tuyere bank 15 ins. above the hearth, in quantities adjusted to maintain a reducing atmosphere within the interstices of the bed. In addition, careful attention is paid to bed temperatures, which run from 1,080° to 1,100°C. Under these reducing conditions, 90 per cent of the cadmium and 92 per cent of the lead in the feed are eliminated, the sulphate sulphur content is decreased by 0.5 per cent, sulphide sulphur is held at 0.6 to 0.08 per cent, and the zinc content correspondingly in-creases. The fuel value of the natural gas is recovered as extra steam, which carries a credit. There are some added difficulties with fume accretions, gas conditioning and gas -cleaning, some of which have yet to be overcome."

Jan 1, 1967

By M. El Tokhi, H. Arman, B. M. Amin

"This paper aims to overview some mechanical and physical features of the gabbroic rocks. The study has two phases: filed study/in-situ measurements and laboratory work. During the field studies, rock block samples were collected from different locations of the study area to represent the different types of the gabbroic rocks. Either core or rock samples for various tests were prepared from rock samples taken to the laboratory. The unconfined compressive strength (UCS), indirect tensile strength (ITS), point load index (PLI), Schmidth hammer rebound value (SHV), slake durability index (SDI), sonic velocity (SV) and unit weight (UW) test were carried out either on the selected rock block samples or core samples.INTRODUCTIONThe geology of the United Arab Emirates (UAE) has been divided into three major rock units (Lippard et al., 1986); an autochthonous succession, allochthonous units composed mainly of Mesozoic rocks and include the Sumeini Group (concomittent slope sediments), Hawasina Complex (basinal sediments) and the Semail ophiolite nappe (massive slice of former oceanic crust), that were emplaced as a series of thrust nappe in the Late Cretaceous and Neo-autochthonous sequence of Maastrichtian and Lower Tertiary sediments.The Semail Ophiolite (600 km long and up to 150 km wide) is thought by some authors (Glennie et al., 1990) to have been generated along a subduction related back-arc spreading axis during the Cenomanian-Turonian and was obducted onto the Arabian continental margin during the Campanian. Others, however, consider it to represent a primitive arc-spreading center related to oblique subduction Lippard et al., 1986). The Ophiolitic rocks in the study area comprise mantle and crustal sequences. The mantle peridotite and crustal gabbros are the dominant rock types of the exposed Semail Ophiolite north of the Hatta zone. This paper is only concentrated on the gabbroic rocks."

Jan 1, 2015

By P. A. Bahri, D. G. Dixon, T. M. Woodward

A comprehensive mathematical model of the Sherritt-Gordon ammoniacal pressure leaching process at K winana Nickel Refinery has been constructed. The process is comprised of six autoclaves functioning as a three-stage leach circuit, operating over the temperature and pressure ranges of 85-95°C and 750-1000 kPa, respectively. The process chemistry forms a complex series-parallel reaction network, characterised by: (1) the gas-liquid mass transfer and reduction of oxygen, (2) the oxidation of eight distinct minerals, (3) the oxidation of sulphur, and successive reactions involving various intermediately oxidised sulphur species, and (4) the oxidation of Fe(II) to Fe(III), and subsequent precipitation as a hydrated ferric oxide. Material balances were developed for species in all three phases, and an energy balance to account for all reactions and phase conversions. The multiple convolution integral (MCI) statistical reactor model was employed for the scale-up of particle kinetics. The model has been validated against plant data, and simulation results are in agreement with plant performance.

Jan 1, 2005