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By Gerald C. Smith

Introduction Newmont Mining Corp.'s Carlin Gold Mining Co. mines gold ore and waste material from four open-pit mines in Northeastern Nevada. Combined production rate is 24.5 Mt/a (27 million stpy). The company is producing gold bullion from the 2.4 kt/d (2600 stpd) Carlin Mill No. 1. and the 2.3 kt/d (2600 stpd) Maggie Creek heap leaching plant. In August 1985, the 6.3 kt/d (7000 stpd) Carlin Mill No. 2 at Gold Quarry came on-line. The total combined throughput of 11.2 kt/d (12,000 stpd) will make Carlin Gold Mining one of the largest US gold producers. Feasibility studies are underway to increase the total gold out-put from Gold Quarry. This will be done by adding a continuous dump-leaching process that will recover gold from lower grade ore. History In 1961, Newmont exploration geologists located claims in the Lynn Creek mining district near Carlin, NV. An exploration drilling program revealed significant gold mineralization. A stepped-up drilling program revealed an ore body with an estimated 10 Mt (11 million st) of ore containing 109 t (3.5 million oz) of gold. Test results in 1963 allowed metallurgists to develop the flowsheet and design for a 1.8-kt/d (2000-stpd) countercurrent decantation (CCD) cyanide plant. Carlin Gold Mining Co. was formed to operate the property. Carlin purchased its first mining equipment in 1965. This consisted of two Bucyrus-Erie 2.7 m3 (3.5 cu yd) shovels and nine 27.2 t (30 st) Wabco Haulpak trucks, two Inger¬soll-Rand track-mounted drills, one Chicago Pneumatic T-650 rotary drill, one rubber tired Michigan 280 dozer, one Caterpillar D-8 36A track dozer, one Caterpillar 16 motor grader, and the necessary ancillary equipment. The fleet was capable of mining 3.2 Mt/a (3.5 mil¬lion stpy) working two eight-hour shifts, five days a week. In 1967, one P&H 1500 3.8 m3(5 cu yd) diesel electrical shovel and three 59 t (65 st) Dart trucks were added to the fleet, along with a Chicago Pneumatic rubber tire mounted rotary drill. This equipment addition increased the mining capabilities to 5.7 Mt/a (6.3 million stpy). Three separate pits, the Main, East, and West, within a 1.6-km (1-mile) radius of the Carlin mill were being mined. The crew consisted of 46 hourly men and three supervisors. This equals 497 t/ total hourly manshift (548 st) or 407 t/total manshift (515 st). Rising gold prices in the early 1970s allowed lower grade deposits to be mined at greater distances from the mill. The Boot-strap pit, 19.3 km (12 miles) north of Carlin, was started in 1973. Two Hough 45.4 t (50 st) front-end loaders, four Wabco Haulpak 45.4 t (50 st) trucks, and a second track type D-8H dozer were added. The higher grade ore was trucked to the Carlin mill using three

Jan 11, 1985

By T A. J Hopper, B J. Birt, K K. Trofimczyk

Nuclear magnetic resonance (NMR) has been utilised in the oil and gas industry for over 60 years. The technology was recently identified as having potential value in iron ore, where latent bound moisture may affect ore handling even after dewatering and extraction. The first step in introducing this technology to iron ore involved laboratory tests on drill core samples. These results established the parameters for a downhole borehole magnetic resonance (BMR) tool for iron-rich environments, which was subsequently developed. A major challenge involved shrinking what is a very large tool in the oil industry to a slimhole, lightweight, 1-man deployable mining tool.Of primary concern was the ability to measure the very fast transverse relaxation times (T2s) seen in the lab results on iron ore samples. Iron creates local field gradients that significantly decrease the T2 times. As a result, the BMR tool had to be able to measure T2s in the range of hundreds of microseconds, a level not required in clastic sedimentary formations. The choice of T2 cut-offs in iron ore is critical to successfully separating the free and bound fluids. The industry has typically focused on T2 cut-offs in clastics and carbonates, but not in systems with high iron content. Using core analysis results (poro-perm and NMR) we were able to verify the BMR response. The T2 cut-offs were determined from NMR core analysis and then applied to the logs so as to provide a continuous, calibrated permeability log.Field results that highlight the challenge involved in logging in iron-rich environments are presented, as well as some minimum requirements for a successful BMR log. Examples from boreholes in an active iron ore mine in the Pilbara iron ore province in Western Australia are presented, as well as explanations for how NMR data can be combined with bulk density logs to provide a continuous dry weight density log based on the original density-porosity equation from Alger et al (1963).CITATION:Hopper, T A J, Trofimczyk, K K and Birt, B J, 2017. Development of a slimhole downhole nuclear magnetic resonance tool for iron ore – some applications and limitations, in Proceedings Iron Ore 2017, pp 473–480 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By A. M. Keenan, R. H. Carpenter

Geologic faults have always been a plague to the mining industry, and have often reduced a mining venture from a profitable to a marginal operation, and even at times have forced companies to liquidation or bankruptcy. The use of geology as an economic tool in coal mining is not generally recognized, particularly in coal deposits which are horizontal or essentially flat-lying, in which faulting might not be prevalent. However in pitching coal seams, the existence of faults is considered an inherent challenge, as the inclination of the seam or seams per se, is a product of geologic disturbance. The problems of faults are a constant challenge to the management of the Thompson Creek Coal and Coke Corp. in their operations in Pitkin County, Colorado, where high grade medium volatile coking coal is mined. The background for this paper has been provided by the experiences of these operations, in overcoming the effects of faults in mining, and resolving the fault structures. The properties of the Thompson Creek Coal and Coke Corp. are located in central Colorado, 13 miles southwest of Carbondale, Colorado, a tow] on the main highway between Glenwood Springs and Aspen, Fig. 1. The elevation at the mine portals is approximately 8000 feet: there is a relief of some 2.000 feet to the adjacent ridges rising away from the [nine portals. 'The entire present production of these properties totaling 180.000 tons of clean coal per year is trucked to the railhead at Carbondale, Colorado, from whence it is shipped to the Geneva Steel Plant at Provo, Utah. The properties were initially opened in September 1952. A total of 125 men are currently employed with the production conting from the Number 1 and 3 Mines, and development workings of the Number 2 and 5 Mines respectively. While the No. 2 Vine was opened in 1953 prior to No, 3 Mine, the encountering of faults without sufficient development work accomplished to sustain production, necessitated the diversion of manpower to the other [nines for economic considerations. GEOLOGY '1-he productive coal seams occur in the Mesaverde formation of Late Cretaceous age which outcrop along the eastern edge of the Piance Creek Basin from the Grand Hogback, a part of the southwestern flank of the White River Uplift north of Glenwood Springs, southward through the 'Thompson Creek area and the

Jan 1, 1961

By Raj P. Singh Gaur

Due to high concentration of NaOH in the digested slurry after scheelite digestion, it is diluted to about 4N before filtration to separate sodium tungstate solution from the sludge (residue). However, in practice there may be deviations in the normality of NaOH present in the slurry. There may also be variations in the temperature of the slurry and filtration time. Slight variations in these parameters could cause tungsten losses in the sludge via the back reaction: Ca(OH)2 + Na2WO4? CaWO4 + 2NaOH This paper pertains to the effect of normality, temperature and time on the tungsten losses in the sludge that is separated from ?diluted-scheelite-slurry-in-NaOH? via filtration. Results indicated that tungsten losses in the filtered residue (sludge) were quite significant when the slurry temperature was kept at 70°C or higher. The effect of high temperature was less significant at the slurry normality of 3.6 or higher. Combination of low slurry normality (<3.6) and high temperature (>60°C) resulted into large W-losses in the sludge.

Jan 1, 2006

By Clements R. J, Davey J. M

Development of the process from the pilot stage to the current operation of the Capel, WA plant is briefly described.The design criteria for a larger sized plant are discussed together with factors that relate suitable feedstocks and coal types to the capital cost, capacity and product grade of future plants at locations other than Capel. The application of the process to the direct reduction of iron ores is briefly discussed including its commercial application at Rockwood, Tennessee.

Jan 1, 1980

By Claude Bazin, François Robichaud

"The control of the operation of semi autogeneous grinding (SAG) mills is mainly achieved through adjustments of feed rate, water addition and speed of rotation. With the introduction of image based sensors it is possible to have on-line measurements of the size distribution of the ore feeding a SAG mill. This information could be used for the development of a control strategy to regulate a SAG mill feed size distribution to a set-point. The control of the size distribution is carried out by adjustment of the speed of the ore extractors underneath the ore stockpile. The potential and difficulty associated with the implementation of such control are assessed using a multivariable statistical analysis of data collected from the operation of the grinding circuit of the Agnico-Eagle Goldex mine in Val d’Or, QC. A control strategy for the ore feed size distribution is assessed using a simulator of the ore stockpile operation.INTRODUCTIONThe popularity of autogeneous (FAG) and semi autogeneous (SAG) grinding mills has been increasing over the last 20 years (Napier Munn et al., 1996). These mills use the ore or a combination of ore and steel balls as the grinding media. Since the ore is used as a media for the size reduction the mill ore feed size distribution impacts the performance of the mill. Several papers were recently published on this subject (Dance et al.,2011; Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011) showing the advantages of preparing the feed size distribution to maximize the circuit throughput or mill efficiency (Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011). With the availability of particle size sensor based on image analysis of the ore on a conveyor (Partanen et al., 2001; Bobo et al. 2004; Edwards et al., 2002; Wei & Craig, 2009) it is possible to control the size distribution of the ore feeding autogeneous or semi autogeneous mills (Partanen et al., 2001).This paper describes a method to control a size distribution index to a set point via the manipulation of the speed of the extractors that withdraw the ore from the stockpile feeding the grinding circuit. The paper consists of 4 sections. The first section describes the considered grinding circuit. A statistical analysis of the collected data on the grinding circuit is presented in the second section. This analysis demonstrates the necessity of using real-time adaptation mechanisms to develop a control strategy for the size distribution of a grinding circuit. The third section describes the method used to simulate the ore stockpile operation and the last section describes the preliminary development and assessment of a control strategy of size distribution of the ore feeding a SAG mill."

Jan 1, 2013

The stratigraphy of the Western Coalfield is briefly reviewed and the important units of the Lithgow Coal Measures, particularly the coal seams, are defined. The possibility of coal measures of Tomago age ocurring near the edges of the Sydney Basin is discussed onpresent evidence.Using data obtained from unpublished drilling records, detailed structural, isopachous and lithofaeies maps have been drawn. These show that the structure of the coal basin has been influenced by the underlying basement in many ways.The prominent jointing in the overlying Triassic sandstones is discussed in relation to jointing in the coal measure sediments.It is concluded that in addition to the general knowledge obtained with respect to the coal basin, useful information regarding coal quality and quantity can be gained by the study of broader sedimentary and structural features.INTRODUCTIONThe term &quot;Western Coalfield&quot; covers approximately the area from Katoomba to Rylstone, together with the smaller, separate Ulan area (Fig. 1). The area studied is part of the great sedimentary Sydney basin named by Osborne (1948). The first discovery of coal in Sitlt in the area was made in 1824 by Andrew Brown, although George Bass noted the presence of coal float in the Grose River in 1797. Production is recorded from the Western Coalfield in 1838 but mining was intermittent until 1868 when mines in the Lithgowvalley (producing coal from the Lithgow Seam) came into production. In 1882 the Katoomba Seam was first worked at Katoomba.The work of J. E. Carne (1903, 1908) defined the limits of the Coal Measure sediments and also contributed a great amount of valuable detailed information about the region.

Jan 1, 1960

By L. Kulik, J. den Drijver

Rhenish lignite will continue to play an indispensible role in the energy mix of the German Federal Republic for a long time to come. The use of lignite for electricity generation, upgrading and, if necessary, as a raw material is geared to the long term. The holistic management of opencast mines underpinned by approval law in the long term and a stronger focus on man, the environment and nature contribute to the acceptance of the mines by the local population. The same is true of state-of-the-art lignite uses: as regards their operational flexibility, lignite-fired power plants are ideal partners for the expansion of renewables. It is along these lines that RWE is continuing its power plant renewal programme as planned. With a view to that which will be conceivable the day after tomorrow, RWE is researching future technologies today in order to meet objectives such as security of supply, profitability and environmental compatibility to the same extent in the long term. Another important contribution to acceptance is public transparency and communications as means to support approval procedures and the implementation of measures in all areas related to lignite mining and utilization.

Jan 1, 2011

By Elli Nurminen

In this work the thermodynamics of the metallic sulphate decomposition reactions were studied through thermodynamical calculations and thermogravimetric methods. The decomposition temperatures and mechanisms were determined for cupric sulphate, ferric sulphate and also for industrial flue dust from a copper flash smelting process. The aim was to determine the thermodynamic conditions for sulphate decomposition and to estimate whether the reactions are kinetically likely to take place in the flash smelting process heat recovery equipment. The information is essential in CFD-modelling of the reactions taking place in the boiler and for optimising the process.

Jan 1, 2006

By AIME AIME

AT Williams College, in the quaint old New England town where people still go to the post office for their mail, an interesting institution has come into being as one of the aftermaths of the peace conference at Paris in 1919. The war taught the world many things about economics although much remains to be learned and more to be appreciated. B. M. Baruch, H. A. Garfield, president of Williams, and others who took part in the conference at Paris or in preparation for it, feeling that benefits would accrue from informal friendly discussion of the problems that lead to political differences between peoples, called together a summer conference in 1920. This has now become an annual affair and is coming to be looked upon as an important center for developing and stimulating public opinion. Membership in the Institute is by invitation and the lists change to correspond with the particular subjects taken up. Each year a number of distinguished foreign public men are invited to be the guests of the Institute and to meet men and women from various parts of the United States interested in their special subjects. Round tables, general conferences, and public lectures are the means employed to bring out discussion. The first are organized by groups, each including usually 25 to 40 people interested in a special subject and meeting three times a week for informal discussion. Teachers, writers, economists, engineers, business men, indeed men of all vocations and many shades of opinion, are brought together. Once a week each round table presents in general conference with the members of all other groups the more general conclusions reached in its own decisions. Afternoon and evening lectures are given by the foreign guests and these are open to the public. The lectures and the general conferences are reported widely in the press but the proceedings as a whole are not printed, no resolutions are passed, and no action is taken or contemplated. The whole plan is to furnish a forum for free discussion in hopes that the difficulties of various groups and peoples may be taken up sympathetically and good understanding promoted. There is no creed, doctrine or dogma to which the Institute is committed and widely different views are currently presented. The constant effort is to bring out points of view and the reasons for them rather than to build up convincing arguments favourable to a specific action

Jan 1, 1926

By John H. Fowler

"Most of the aggregate used in Nova Scotia is produced from numerous glaciofluvial and ice-contact deposits scattered throughout the province. Production from bedrock sources is increasing, with most of the coarse aggregate used in the Halifax-Dartmouth area coming from quarries operating within the metro area.A recently completed provincial sand and gravel inventory mapping program has identified some ""resource-poor"" areas where comprehensive aggregate evaluation programs are underway. Although some areas of the province are experiencing aggregate supply problems, large volumes are exported to markets as far away as Bermuda.IntroductionThe Nova Scotia Department of Mines and Energy has been involved with aggregate resource studies for several years, although sand, gravel and crushed stone are not designated as minerals under the Mineral Resources Act of Nova Scotia. Our role has been to provide the aggregate industry with resource data as well as provide similar information to governmental agencies involved with municipal planning, water resource studies and environmental protection regulations. Several private consulting firms use the information in many of their site development studies.We became involved with aggregates in a rather roundabout way. Several years ago, an outcry from inhabitants of a small coastal community over the removal of sand and gravel from a local beach moved the provincial Department of Lands and Forests to take action to protect provincial beaches. We were asked by the Department to provide information and to suggest alternative sources here operators extracting sand and gravel from beaches could relocate. This request initiated an aggregate inventory survey in southeastern Cape Breton, which was later extended to cover the entire province. The initial provincial sand z and gravel inventory survey provided a series of 1:50,000 maps showing the distribution of sand and gravel deposits in the province."

Jan 1, 1982

By R. J. Matetic, David S. Yantek, David K. Ingram

The National Institute for Occupational Safety and Health (NIOSH) has investigated engineering noise controls to reduce sound levels in cabs on air-rotary drill rigs. A recent investigation revealed that some drillers are exposed to A-weighted sound levels exceeding 85 dB even though a cab is used. NIOSH studied the in-cab sound levels of one such rig. First, preliminary tests were conducted in a controlled environment using accelerometers and microphones with spectral analysis to identify the dominant noise sources for in-cab sound levels. The results indicate that vibration transmitted from multiple hydraulic pumps to the control panel produces a dominant spike in the sound level spectrum in the 400 Hz 1/3-octave band. Next, field tests were performed in a production environment to evaluate noise controls to reduce in-cab sound levels. It was found that utilizing hydraulic noise suppressors reduces the structure-borne noise transmitted to the control panel. Further, using hydraulic noise suppressors and enhancing soundproofing reduced the in-cab A-weighted sound levels by as much as 4 dB.

By Larry Schneider

Are you one of the thousands of hunters, fisherman, or hikers who purchased handheld GPS systems over the past several years and then been disappointed in their accuracy and performance. Or maybe you are one of the hundreds of blasters who have attempted to use GPS as a method for locating the exact position of their blast and measure distances from the blast to nearby structures. If so, you may have found that the accuracy of the handheld GPS systems left much to be desired. It may be time to get the units back out of storage and give them another try. As of midnight, May 1, 2000, the federal government has turned off the “error” built into the system known as “selective availability.” Here is a brief explanation of what that means in a question and answer format.

Jan 1, 2001

By Edmond Chin

The area encompassed by the political entities included in this study com-prises 11 million square miles or about 15 percent of the total Earth&apos;s land area. The bulk of the region is contained on the Asian continental land mass. Australia, the world&apos;s largest is-land or the world&apos;s smallest continent, alone is almost as large as the continental United States. The islands of New Zealand, New Guinea, Borneo, Sumatra, and Honshu are among the largest in the world. Collectively, they constitute a land area of 1.1 million square miles or an area about one-fourth the size of the United States. The region is noted for its great rivers. The Chang, Huang, Amur, and Mekong are respectively the fifth, sixth, eighth, and eleventh longest rivers in the world. The Ganges-Brahmaputra has created the world&apos;s largest delta, which covers 30,000 square miles. Abutting East Asia are the Sea of Japan, Dong Hai, Nan Hai, Bay of Ben-gal, and Arabian Sea. In the Southern Hemisphere, there is the Indian Ocean and the South Pacific Ocean. The Continental Shelf adjacent to the region constitutes a large proportion of the world&apos;s readily accessible shelf area. On the other hand, the Philippine and Java trenches and, further out, the Mariana Trench reach to formidable, abyssal depths, downward to 6,000 fathoms. Contrasting to this is Mount Everest, which reaches a lofty height of 29,028 feet. And then there is Xizang, whose high plateaus have been called the roof of the world.

Jan 1, 1992

By Jake Hutchison, Wade Hutchison

The opposition to the project has risen as a result of some political pressures and from public perceptions about the project’s necessity and its impact on the neighborhood. As a result of this controversy, the Underground Conservation Hall was quickly termed “Bredesen’s Bunker” by the Media. Close exposures for blasting, required by the Conservation Hall construction project, have been regulated by specifications that regulate seismic monitoring, pre-blast and post-blast inspections. Planned blasting for the project included blasting to a depth of 30 feet (9.14 meters) within 35 feet (10.67 meters) of the front of the newly renovated Tennessee Executive Residence. Excavation for the project found more competent rock at higher elevations than identified in test drilling which required blasting within 2 feet (0.61 meters) of the side of the Residence.

Jan 1, 2009

By G. Caron, M. Boisclair

In 2005, CANMET-MMSL used its pool of expertise in ground control, open pit and underground mine engineering, mineral processing, information technology and applied mineralogy to launch a mine-to-mill research project. The objective of the project was to optimize the distribution of rock breakage energy among blasting, crushing and grinding activities, thereby maximizing the efficiency of energy utilization within comminution processes. Tests were designed to demonstrate that this approach could reduce the energy consumption, thus contributing to the reduction of Green House Gas (GHG) production in the Canadian mining industry. The project was accomplished in collaboration with DynoConsult and Dyno Nobel Canada Inc., a world leader in commercial explosives. Data analysis from 12 blasts (six with electronic and six with pyrotechnic detonators) in three different geological formations of a quarry (soft, medium and hard rock) shows that electronic blasting technology increases rock fragmentation by 15% (in hard rock) to 20% (in soft rock). A more uniform rock fragment size distribution is also obtained. The impact of the improved quality blast product on downstream processes of the quarry is a productivity increase of 5% in rock excavation and transportation, an energy reduction of 10% at the primary crusher and an increase of 15% of the primary crusher throughput. A soft-sensor prototype, based on primary crusher data (i.e. energy consumption, throughput, feed and product size distribution) and a simplified computerized process model, was developed for on-line measurement of the rock operating work index. Additionally, 385 rock samples and specimens were collected and prepared to determine the tensile and compressive strength of the rock material, to evaluate the aggregate crushing work index, and to examine the development of micro- and macro-fractures by means of binocular and SEM microscopy. Blast-induced rock damage was evaluated at the end of the laboratory testing program. Even though a reduction of rock hardness of around 30% was observed after blasting, the impact of the blasting method (i.e. use of electronic or pyrotechnic detonators) on the induced rock damage could not be observed. It is either absent or not perceptible with the accuracy of the measuring techniques and the number of samples analyzed.

Jan 1, 2007

By A Paz, H Lehto, M +stholm, I Roitto

Nowadays, the demand for a finer grind in minerals processing has set new challenges within the industry, particularly for grinding technology. Apart from a finer grind, energy efficiency is also a key driver in optimising comminution technology.Stirred milling technology, already proven in many other industries, delivers a modern, sophisticated, flexible and energy efficient grinding solution for fine and ultra fine grinding in minerals processing. Fine grinding technology is utilised particularly in concentrate regrinding to complete the liberation of valuable minerals after the first stage of concentration. Maintaining the correct particle and particle size distribution of the regrind product is crucial for downstream process performance. Stirred milling technology offers the unique possibility for online control and optimisation of the regrind product particle size. This paper describes the basis of this online control possibility and discusses the implementation of stirred milling technology in minerals processing, particularly in regrinding applications. The paper will also outline management and control of fluctuations in feed rate tonnages as well as particle size fluctuations in concentrate regrinding.CITATION:Roitto, I, Lehto, H, Paz, A and +stholm, M, 2013. Stirred milling technology - A new concept in fine grinding, in Proceedings MetPlant 2013 , pp 190-201 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By S. K. Kawatra, A. K. Bakshi, T. C. Eisele

An on-line rheometer, suitable for use with slurries, has been developed at Michigan Technological University. This rheometer can be used with both Newtonian and non-Newtonian slurries, and produces complete shear-rate/shear stress curves which characterize the time-independent rheology of the slurry. The sensor utilizes the Hagen-Poiseuille equation and Boyle&apos;s Law to calculate the shear rate, slurry flowrate, and shear stress from a series of pressure measurements. The design of the unit allows the measurement sample to be continuously collected from operating process streams in the often-hostile on-line environment. The shear rate/shear stress curves can be used to conveniently calculate the apparent viscosity at any given shear rate, and also to measure any yield stress or other deviations from Newtonian behavior.

Jan 1, 1999

By N. Kumar Kittusamy

ALTHOUGH MANYSTUDIES HAVE SHOWN an association between operating heavy construction equipment and symptoms of musculoskeletal disorders (MSDs), little research has been performed that systematically characterizes the exposure of operating engineers to ergonomic hazards. This study evaluated: 1) vibration at the seat/operator interface;2) transmissibility of vibration in the Z-axis; 3) psychophysical ratings of vibration level and vibration discomfort; and 4) postural requirements of the job. Results indicate that the digging operation had higher levels of total weighted acceleration than high- or low-idling conditions. Transmissibility data showed that the seat amplified vibration, particularly in the lower frequencies. Seats demonstrated that they may not be sufficient in protecting operators from long-term effects of vibration exposure. High positive correlation was found among subjective ratings (vibration discomfort and vibration level), but moderate positive correlation was found between subjective ratings and quantitative vibration levels. Postural evaluations revealed that the operators were required to assume awkward postures of the neck, shoulder and trunk while performing their jobs. Work-related injuries and illnesses pose a continuing threat to the health and well-being of American workers. The construction industry has been historically recognized as having higher rates of fatality, injury and illness than other industries (McVittie285+; BLS). In 1994, an estimated 218,800 lost-work-day injuries were reported in the construction industry (BLS). Construction also had the second-highest incidence rate for sprains and strains. Although the industry has made progress since then, injuries and illnesses, including MSDs, continue to because for concern.

THE choice of a pumping plant for the drainage of a mine is a matter of such importance that it is obvious that in a short paper it is impossible to go fully into the reasons governing the adoption of any particular type. The author, therefore, proposes to briefly discuss the methods.in vogue, and, as far as possible, to point out the advantages and disadvantages of the numerous systems. The probiem is of extreme importance to the mining engineer, and it appears that in the past sufficient thought has not been given to this branch, as shown by the numerous failures which are encountered.When water is met with in large quantities, the development of the mine depends upon the pumping plant to such a great extent that the most careful consideration should be given before deciding on any particular scheme for drainage. The pumpingplant in a mine should be looked. upon in the light of an insurance policy, and should be treated as such, care being taken that the premium is as low as possibl~, and to ensure this it is necessary that the most efficient plant be secured. Local conditions play such an important part ill the design of a plant that no hard and fast rules can be laid down. When the amount of water to be handled is small, and there is no possibility of any increase...

Jan 1, 1912