Search Documents

By E. C. W. Perryman

Materials research and development has played an important role in the commercial success of the CANDU- PHW nuclear reactor and in the production of heavy water. Both capital investment and energy conservation demand very high component reliability in such systems. The interactions among reliability, plant performance and economics will be discussed in relation to materials research and development. Likely materials requirements for the nuclear industry over the next twenty five years will also be discussed.

Jan 1, 1977

By M. A. Bergougnou, I. Inculet, K. I. Burgess

This paper describes the electrostatic methods of separating various minerals, reviews the principles of fluidization and outlines the technique of electrostatic sorting in fluidized beds. The application of the method to the benefication of coal is emphasized.

Jan 1, 1970

By F. A. Auld

"Traditionally deep shaft sinking from the ground surface was carried out using drill and blast methods. Although large diameter blind shaft drilling has been carried out successfully on numerous occasions previously, including as early as 1852 in Germany (Auld, 1995), little attempt has been made until more recently to mechanise the shaft sinking excavation process using down-the-hole machines. This paper reviews the development of deep shaft sinking machines from the early 1970’s up to the present day. INTRODUCTION Mechanical excavation methods can significantly improve excavation performance, in order to access natural resources faster, and labour safety is increased compared to drill and blast operations. However, shaft sinking machines need to be capable of accommodating all the basic requirements for deep shaft sinking, namely: 1. Excavation and muck removal 2. Ground stability control 3. Groundwater ingress control 4. Temporary lining installation 5. Permanent lining installation and watertight sealing 6. Ventilation 7. Secondary means of egress for personnel In addition, how the machine operates in the shaft is an important factor, either slung on ropes from a surface headgear or on its own in the bottom of the shaft. An all-embracing machine which can deal with all of the above conditions is impossible but many of these requirements can be incorporated into a single machine. Deep shaft sinking also differs greatly from normal tunnel construction which employs the use of either a roadheader arm installed within a shield or a full-face tunnelling machine for excavation. Hydrostatic pressure and ground stability problems increase with depth, whereas in tunnelling the depth is normally relatively shallow and the aforementioned factors remain approximately constant along the tunnel length. DEEP SHAFT SINKING MACHINES All the shaft sinking carried out previously in the UK was by the traditional method of drill and blast. Elsewhere, in other parts of the world, attempts have been made to mechanise the process."

Jan 1, 2019

By J. W. Craig

THERE are, broadly speaking, three classes of refractories: acid, basic, and neutral. Fireclay, diaspore, silica, and the sillimanite group of minerals are included in the acid class, which for the most part are not very resistant to basic slags. The neutra! class includes chrome, graphite, and silicon carbide, while most important in the basic class are magnesite and dolomite. Although chrome is a neutral refractory, it has no sharp distinction from magnesitic refractoriness. The two are mineralogically (1) and chemically related, and there is available on the market a complete range of brick from straight chrome to straight magnesite. In many indus trial applications, one. type may be replaced by another. The present paper is confined entirely to such refractories. The following types of basic and neutra! brick, each sold under sorne special trade name, are available for use in Canada: (1) Burned chrome from crude ores (2) Burned chrome from treated ores (3) Chemically bonded (unburned) chrome-magnesite ( 4) Burned chrome-magnesite (5) Chemically bonded ( unburned) magnesite-chrome (6) Chemically bonded (unburned) high-iron magnesite (7) Burned high-iron magnesite (Regular) (8) Burned low-iron magnesite (9) Burned olivine-magnesite (10) Burned magnesitic dolomite-chrome (Magnecon) (11) Chemically bonded magnesitic dolomite-chrome (Magmecom) (12) Dolomitic brick

Jan 1, 1936

By Niels Verbaan, Ernesto Bourricaudy, Ronald Molnar, James Brown, Sunil Jayasekera

"SGS Minerals commissioned an internal R&D program to develop in-house expertise to design, set up and operate REE separation pilot campaigns at its Lakefield, Canada site. A team approach was used that included expert consultants in the field of REE separation as well as in-house expertise supported by the on-site Analytical Laboratories.A mini pilot scale SX circuit was designed and constructed consisting of several modular banks of 30 stages each. About 80 stages of mixer-settlers were used to separate Pr and Nd from La and Ce contained in a synthetic REE chloride stream simulating the raffinate from an initial La-Nd|Sm-Lu+Y separation.Two pilot campaigns were operated totalling 25 days of 24/7 operation with 99.4% plant availability in the final 20 day campaign. Purities of > 99.9% in the Pr-Nd strip liquor and > 99% in the La- Ce raffinate were achieved and simultaneously sustained in the second campaign for prolonged operating periods. Key to controlling and adjusting the circuit was the rapid assay turnaround (as low as 2 hours) provided by the on-site SGS analytical lab. This permitted the operating team to modify conditions and observe the effect of changes relatively quickly considering the large number of stages. A portable XRF analyser was also used to track evolving assay trends in the circuit. The small physical size of the circuit enabled longer operation with a limited amount of sample.This paper discusses the design of the circuit, operating conditions, some of the key operating factors and controls and results obtained.INTRODUCTIONSGS Minerals commissioned the design of and built a solvent extraction (SX) pilot plant for the separation of rare earth elements (REE). The plant consists of a battery of 120 mixer-settlers set up in a dedicated piloting facility.The purpose of the programme was to develop capabilities and in-house expertise in REE SX separation technology. The program aimed to establish operating procedures, sampling regimes, and analytical methodologies and protocols for this type of process/plant. A team comprised of SGS personnel and several external consultants with prior industrial and REE separation piloting experience was assembled to achieve these objectives."

Jan 1, 2016

By M. Courtin, D. Berthelot, M. Haggis, D. McClarty, R. Payne

Over forty years of uranium mining in the Elliot Lake region of Ontario (1956–1996) has resulted in the production of over 300 million pounds of uranium. With the completion of mining activity, Rio Algom Limited and Denison Mines Limited are utilizing progressive environmental technologies and management systems to reduce and manage the environmental risks associated with the 150 million tonnes of potentially acid-generating tailings in nine regional waste management areas. Water covers designed to reduce oxygen entry and, thereby, significantly inhibit acid generation, have been applied at six of the sites with the Quirke site serving as a demonstration site for the Mine Environmental Neutral Drainage program. All five of Rio Algom Limited’s effluent treatment plants are monitored and controlled from a central control station utilizing a Supervisory Control and Data Acquisition (SCADA) system based on “Fix Dmacs” technology. Scheduling, auditing and reporting of plant operating and environmental monitoring programs for the entire watershed are controlled utilizing the Regional Environmental Information Management System (REIMS). Proper application of these technologies and management systems facilitates delivery of cost-effective environmental monitoring, care and maintenance programs at these sites and provides tools to demonstrate compliance with all environmental performance criteria.

Jan 1, 1999

By M. A. Vasina, I. A. Matveeva, E. A. Naumova, V. V. Doroshenko, N. A. Belov

"Using the calculated (Thermo-Calc software) and experimental methods (SEM, TEM, EMPA, DSC, XRD, etc.) the phase composition, structure and hardening of aluminium alloys of the Al-Ca-Zn-Mg system were studied in the following range: 2. 5%Mg, up to 10% Ca, and up to 14% Zn (wt%). Fragments of this quaternary phase diagram in the aluminium corner were constructed, including the liquidus surface, as well as some vertical sections. It was shown that the relatively large amount of zinc enters in the Ca-containing phase, which formula can be described as (Al,Zn)4Ca. An increase of Zn content leads to formation of Al4Ca primary crystals at lower concentrations of calcium. The eutectic (Al)+(Al,Zn)4Ca has a fine structure and aluminide particles are capable to spheroidization during the heat treatment at temperature 500 C. The maximal level of hardness observed on calcium containing alloys was higher than 200 HV, what gives the reason to expect good strength properties. With an example of an Al-9% Zn-2,5%Mg-3,5% Ca model experimental alloy based on the (Al)+(Al,Zn)4Ca eutectic, a principal possibility of manufacturing thin rolled sheets was demonstrated.INTRODUCTION Aluminum alloyed with calcium was first studied in 1970-80s by such authors as Piatti (1976), Moore (1978, 1980), Il'enko (1985), Swaminathan (1990), and Perez-Prado (1997) as superplastic materials. In particular, the alloy systems Al-Ca-Zn were studied (Il'enko, 1985, Swaminathan, 1990, Perez-Prado, 1997). For some time there was no new published works concerning the aluminum-calcium alloys. During the last years many works were published dedicated to the calcium alloying of magnesium alloys (Kim, 2011; Xu, 2011; Aljarrah, 2008; Bakhsheshi, 2014). This urged the authors (Belov, Naumova & Akopyan, 2016) to start studying cast and wrought aluminum-calcium alloys for construction (2008–2014). There is almost no information in the literature concerning triple and more complex diagrams of the aluminum-based system states with calcium and other elements. In recent work, parts of the state diagrams are plotted for the aluminum angle zone: Al-Ca-Mg-Sc (Belov, Naumova & Bazlova, 2016), Al-Ca-Ni-Sc (Belov, Naumova & Bazlova, 2017), Al-Ca-Si-Sc (Belov, Naumova & Akopyan, 2017) and others. Special attention was paid to the study of the system Al-Ca-Zn-Mg (Naumova, 2017). Based on this system creation of advanced extra-high tensile alloys is planned. Wrought extra-high tensile alloys series 7??? based on the system Al-Zn-Mg-Cu are well studied."

Jan 1, 2018

By M. A. Perras, M. S. Diederichs

"The Niagara Tunnel Project (NTP) is a 10.1 km long water-diversion tunnel in Niagara Falls, Ontario, which was excavated by a 14.4 m diameter tunnel boring machine. The excavated rock types included limestone, sandstone, siltstone, shale and mudstone. Based on observations and measurements the overbreak was divided into four zones. Approximately half the tunnel length was excavated through the Queenston Formation, which locally is a shale to mudstone. Three of the four overbreak zones were within the Queenston. Zone 1 includes the formations above the Queenston Formation, Zones 2 and 4 are border regimes with little or no influence from St. Davids Buried Gorge and Zone 3 is the area influenced by the gorge. Zones 2 through 4 can be generally summarized as having overbreak as the result of stress induced spalling. Zone 2 marks the transition from slabbing at the Whirlpool contact in the stress shadow to spalling towards Zone 3. The behaviour of Zone 3 is interrupted from the typical high stress behaviour due to the presence of St. Davids Buried Gorge. As the tunnel passed from the gorge the high regional stresses induce spalling, which creates the typical notch shaped overbreak geometry of Zone 4.Three modelling approaches were used to back analyze the brittle failure process at the NTP: damage initiation and spalling limit, laminated anisotropy modelling, and ubiquitous joint approaches. Analyses were conducted for three tunnel chainages: 3+000, 3+250, and 3+500 m because the overbreak depth increased from 2 to 4 m. All approaches produced similar overbreak geometries to those measured. The laminated anisotropy modelling approach was able to produce overbreak depths and chord closures closest to those measured, using a joint normal to shear stiffness ratio between 1 and 2. The back analysis results were able to produce sets of stress and strength inputs for different sections of the tunnel at the transition from overbreak Zone 3 to 4. The back analysis procedure demonstrates the importance of including the anisotropic stiffness in the numerical modelling approach to correctly capture the overbreak geometry and deformations around underground excavations."

Jan 1, 2015

By J. R. Goode

ABSTRACT Aurora Energy Ltd. is considering a 10,000 t/d process plant to produce 97 million lb (43,998,460 kg) of U3O8 over a 17-year project from uranium deposits in coastal Labrador. This paper summarizes the test work, mostly done by SGS Mineral Services in Lakefield, Ontario, and the economic studies supporting flowsheet selection. The proposed flowsheet includes semi-autogenous grinding (SAG) and ball milling, acid leaching using air/SO2 as an oxidant, and resin-in-pulp (RIP) extraction of uranium from the leached slurry. Other unit operations examined include ore sorting, heap leaching, liquid- solid separation, solvent extraction, and nanofiltration for eluate upgrading. We also review the extensive environmental test work and studies that were completed.

Jan 1, 2012

By M. Epiney, A. Ghahreman, R. Kim1and

"Pre-oxidation and cyanide leaching behavior of gold in the presence of sulfide minerals were reviewed, focused on the effects of oxygen injection in the gold leaching process. Generally, pre-oxidation and gold leaching kinetics from iron sulfide refractory minerals, such as pyrite, pyrrhotite, marcasite, pentlandite and arsenopyrite, can be enhanced with higher dissolved oxygen (DO) concentration. However, most of copper sulfide minerals dissolved well both in water and cyanide solutions, and copper from the minerals consumed DO and cyanide to oxidize and leach. Only in the presence of chalcopyrite, gold leaching was effectively occurred with increasing DO. However, chalcocite and covellite severely retarded gold leaching. Stibnite, an antimony mineral, formed a passive film on the gold surface under any DO conditions, and it slowed gold leaching. This impeding effect can be alleviated by leaching at low pH or adding lead salt. Using oxygen and lead together can make synergistic effect in oxidation of sulfide minerals and can enhance gold extraction. Depending on the mineralogical characteristics of the ore, the optimum DO and lead concentrations can be optimized. However, lead can cause environmental problems, and so its dosage should be minimized or eliminated by substituting it with oxygen injection.INTRODUCTIONGold ores containing sulfide minerals are becoming more significant as high grade gold oxide deposits are continuously becoming difficult to find. In light of this situation, to produce more gold, recovery methods from refractory gold ore containing various sulfide minerals should be investigated. Generally, sulfide minerals have impeding effects on gold leaching: formation of a passive film on the gold surface, high consumption of chemicalssuch as cyanide and oxygenduring leaching, reduction of gold cyanide by sulfide ions, etc. (Senanayake, 2008). Therefore, sulfides must be properly treated for better gold recovery. Pre-oxidation of sulfide minerals by injecting pure oxygen can decrease the impeding effects in gold leaching. Prior to cyanidation, sulfide minerals can be oxidized to metal hydroxide and sulfate form, which consume negligible cyanide in the following cyanidation circuit (Bodnaras et al., 1993). Moreover, gold cyanidation can be enhanced by increasing concentration of the dissolved oxygen (DO). In general, the optimum concentration ratio of [CN-]/[O2] is calculated as 6, but it goes higher in the real system (Marsden &House, 2006), which means that the reaction is typically controlled by DO concentration."

Jan 1, 2017

By W. D. Robson

THE prevention of silicosis by metallic aluminium has been reported by Denny, Robson, and Irwin in two papers. The first (1) was published in 1937; the second (2), in 1939. The results definitely established that silicosis was prevented in animals by the inhalation of small quantities of aluminium. The present communication records subsequent progress in this field of research. HARMLESSNESS OF ALUMINIUM Animal experiments having served their purpose, it became necessary to consider means to test the discovery on humans. A question for immediate consideration was: Is aluminium harmful to man when inhaled as a fine powder? While the animal experiments were reassuring, since they conclusively showed the powder to be innocuous when breathed by animals, it was, nevertheless, desirable to have additional reassurance with regard to its effect upon human beings. Through the courtesy of the Aluminum Company of America and especially the valued interest in this problem displayed by that Company's Director of Research, Dr. Francis C. Frary, a study was made of the records pertaining to the health of a group of 125 employees who had for many years been engaged in the manufacture of finely powdered, metallic aluminium for the paint and ink industries. The conditions were such that these employees had inhaled varying and oft-times very dense concentrations of this powder daily over periods ranging from 6 to 23 years, the average for the group being 12 years. X-ray pictures of their chests showed no abnormalities attributable to aluminium. Their general health seemed better than that of the 3,000 workers in other sections of the plant. In fact, the early films of three employees in this group of 125 showed shadows suggestive of minimal tuberculosis, which shadows were not discernible in films taken after considerable periods of exposure to aluminium powder. The harmlessness of aluminium was, by this study, reasonably well established at the outset, a finding subsequently verified by Ontario research on humans.

Jan 1, 1944

By Mary A. Wells, Amir Hadadzadeh, Mark A. Whitney, Stephen F. Corbin

In an effort to produce less expensive titanium sheet via roll compaction, the room temperature compaction behavior of titanium sponge granules (99.9% pure, Alfa Aesar) was studied under uniaxial die compaction. The titanium sponge granules were irregularly shaped, with a high degree of porosity, having a maximum particle size of 3mm. Manual die compaction was conducted using a Carver hand press, in a hardened tool steel die with 12.61 mm inner diameter. Uniaxial die compaction in a hardened tool steel die with 9.50 mm inner diameter was also performed using a Gleeble® 3500 thermal-mechanical simulation testing system which allowed for controlled deformation rates. Compaction behavior of the titanium sponge was studied using well-established compaction equations (Heckel, Panelli-Filho and Ge), and it was observed that compaction rate influences the room temperature compaction behavior of this material. The Heckel analysis of the titanium sponge showed that the behavior of the material could be analyzed in two compaction pressure regimes. In the low pressure regime (<100 MPa) the granules exhibited high compressibility, while; in the high pressure regime (>100 MPa) lower compressibility of the titanium sponge was observed.

Jan 1, 2015

By Gordon W. Hines

This paper, dealing with network planning in an industrial complex, discusses the type and size of project that can be handled on a manual basis. After a review of the fundamentals of network planning, and specifically of the Critical Path Method, the author analyses several different types of projects, each with its own characteristics. Some can be handled in conjunction with a computer, but others can be dealt with equally well without one. Among the projects discussed are a blast furnace reline, the installation of a billet mill flying shear, and routine maintenance-type operations.

Jan 1, 1967

By M. E. Charles

The use of water flowing as a lower layer to reduce pressure gradients in petroleum pipelines was investigated using 17.5 deg. A.P.I. Lloydminster crude oil in a 1-inch laboratory pipe-line and a 21h-inch field pipeline. The method was found to be very effective in reducing the pressure gradient below that for the oil flowing alone. The factor by which the pres-sure gradient was reduced varied with the percentage of water added, and in general exceeded 10 for water contents ranging from 40 to 60 per cent. Within this range of water content the pressure gradient reduction factor was independent of the oil flow rate.

Jan 1, 1960

By J-g. Cui, X-b. Guo, J-j. Wang, J. Qiao, H. Tian

"Rare earth elements have unique properties because of the special electronic structure. In this paper the improvement of refractory material performance by the light rare earth oxides was introduced. The experiments showed that adding a bit of rare earth oxide could obviously improve the performance of the refractory material. INTRODUCTIONIn recent years, refractory materials are widely applied in the steel smelting process as a ladle lining material. In China, although the total production of fire-proof material exceeds normal demand, but the quality and variety of fire-proof material still have a big gap with world advanced level. A number of refractory products need to be imported from abroad. With the rapid development of domestic steel production, the ladle lining with refractory is gradually running after the world advanced level on production technology, production variety, and quality level. It replaces some imported products meeting the needs of the development of the iron making production. Therefore, there is an important significance to research on solving the problems of the ladle refractory reasonably and avoiding or reducing blind and not proper use of the imported refractory ( Jing, 2007).On the other hand, rare earth oxide has some special excellent properties. Firstly, they are very good refractory materials with their high melting point;Next, they have good resistance to water and alkali resistance function;Thirdly, it is easy for rare earth oxide to generated composite oxide reacting with other metal oxide,achieving the purpose to improving the material properties (Xu, 1978; Diao, 1979). China has a variety of rare earth resources,and rare earth resources is more advantageous in Baotou,taking up about 36 percent of world reserves,which is the world's top of rare earth mineral. In recent years the rare earth products output has risen sharply and many varieties and specifications have appeared. So it is necessary to study the new field of rare earth compound to open up new markets. Thus, it has a very vital significance to promote the further development of rare earth industry, adjust the rare earth products structure, ease the contradiction between supply and demand, and improve refractory products quality and grade in order to better serve the main body production.I In this paper, the experiments are mainly for 210 tons of Al2O3-MgO style series refractory materials belong to ladle lining bag from Baotou Iron & Steel Group Corporation Sheet Factory. The improvement to the effect of refractory material performance is explored by using light rare earth oxides as additives."

Jan 1, 2012

By F. E. Senftle

Introduction The usual laboratory methods of uranium analysis are either tedious, time-consuming chemical procedures or elaborate physical methods requiring sensitive equipment. There is thus an urgent need for a method of estimating the uranium content of ore samples by approximate analysis in the field. When a new property is being developed, it is desirable to know, with the least possible delay, the uranium content of channel samples in order to guide the diamond drilling and digging operations. Prospectors, too, require approximate analyses of their hand specimens to evaluate their discoveries. To satisfy the demand for these types of analyses, several field procedures have been tried. Two general plans can be followed. One is fast but will yield only a rough estimate. The other is slightly longer but, if done carefully, will give an assay probably within 10 per cent of the true value. For field operation it is necessary to strip the more accurate laboratory methods of analysis of all refinements because of the limited equipment and skilled techniques at hand. Most of the corrections normally applied, with the exception of that for equilibrium, will not alter the gross analysis to any appreciable extent. When uranium atoms in pitchblende disintegrate, they break down into other radioactive elements, and eventually the number of elements being formed is equal to the number breaking down. The ore is then said to be in equilibrium. Certain geological processes, however, such as leaching, may selectively remove some of these elements and hence reduce the radioactivity of the ore sample. The ore is then said to be out of equilibrium. The field analysis may then be in error by as much as 50 per cent since the apparatus is calibrated with standards that are in equilibrium. However, such a large error due to loss of equilibrium is the exception, and in most cases uncorrected field types of analyr.is are justified.

Jan 1, 1949

By R. A. Hemstock

"Simple classification systems are now being used which will describe adequately the surface vegetation, the topography and the peat for any muskeg condition. Good progress is being made in determining some of the mechanical properties of muskeg and it is apparent that the science of soil mechanics will apply largely to these studies. Correlation is also indicated between shear strength as determined by the shear vane tester and vehicle performance. Several tracked vehicles are now available which perform well in muskeg and advances in this field have come rapidly in the past few years. Testing is under way on the largest of all muskeg vehicles -the thirty-five ton Musk Ox. This vehicle will fill the last gap for the oil industry and will make possible the movement of large drilling rigs at any season of the year."

Jan 1, 1960

By W. C. Whittaker

"This paper gives a brief resume of the changes in the market picture for Western coal since 1948. It then analyzes present markets and recent developments in Western Canada, the western United States and Japan, and forecasts future markets in these areas to 1975.INTRODUCTIONCOAL HAS BEEN MUCH IN THE NEWS OF LATE, both in the United States and in Canada. In the United States, this is because of the booming condition of the industry and because of the purchase of control of a number of America's largest coal producers by the integrated oil and metal producing companies seeking additional fossil fuel reserves and diversification. In this regard, it is interesting to note that ownership of America's largest strip coal producer was recently acquired by one of the world's largest copper mining companies. In Canada, the conclusion of several large-scale, long-term contracts for the sale of coal to the Japan Steel Group and the projected use of Canadian coal in steel mills in the western United States has focused much attention on the coal industry."

Jan 1, 1968

By Frank Otten, Jochen Greinacher

"In July 2017, Deilmann-Haniel signed a contract with IOO Slavkaliy to sink two 750 metre (m) deep freeze shafts for the Nezhinsky Potash mine in Belarus. This is the second shaft project where this technology is employed after two over 1,000 m deep shafts for a potash project in Saskatchewan, Canada, have been sunk by the application of the Herrenknecht Shaft Boring Roadheader (SBR) technology. Developed to sink shafts for green field projects in soft to medium hard rock, in frozen or unfrozen geology, the machine technology utilizes a roadheader-type cutterhead on a telescopic boom to mechanically excavate the rock, and a pneumatic mucking system to convey the muck from the face into the buckets. This leads to a manless face during the sinking cycle and thus a significant improvement in terms of workplace safety. For the Nezhinsky project, the SBR design was significantly modified in close cooperation between Deilmann-Haniel and Herrenknecht, based on the available experience and the special requirements of the project. Such modifications have been for example the adaptation of the Pneumatic Mucking System to cope with wet material as well as dry as originally planned or the shaft lining moving from shotcrete application to jump for and tubbing installation for which a step-change hands-off tubbing erector for the placement of segments was designed. Further modifications to optimize the machine technology for the requirements during shaft sinking were applied on the two machines for the Slavkaliy project as well as several revisions to match the special project requirements. The SBR is suitable for soft and medium hard rock up to 100 MPa UCS. The main design limits are maximum weight of the machine with 400 tonnes and length or height of 50 m due to the depth of the pre-sink. The Pneumatic Mucking System was changed in all components, sheaves and rope arrangement were redesigned and the concept of the hoist system was also re-engineered. The SBR in Belarus is configured for a daily sinking rate of three metres and all systems behind the cutting boom are not the bottle neck of the whole system. The works on site started in November 2017 including freeze hole drilling, construction works, site setup, installation of hoists winches, permanent headgears and other components required for sinking. The SBRs arrived on site in June/July 2018 and were preassembled on surface and then lowered into the 50 m pre-sink. SBR #1 started full face sinking in mid-December 2018, and SBR #2 in late January 2019. By the end of February 2019, the machines were at 150 m and 100 m depth respectively, and achieved up to 3.6 m/day concrete lined shaft. The SBR and the sinking system, the experiences, problems, technical solutions and performances of this challenging project will be presented in this paper."

Jan 1, 2019

By G. R. Phare

Explosives formulation is dictated by desired field performance, which in turn is dependent on such physical properties as strength, velocity of detonation, sensitivity, and water resistance. The design of explosives to obtain these properties is discussed with some reference to detonation and rock mechanics theory.

Jan 1, 1958