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By A. P. Squelch

The question of what stress condition exists in the hangingwall of tabular stopes remains topical and largely unanswered. Limited field data exist to quantify the situation and provide calibration for investigative computer modelling exercises. Work conducted in1989 and 1990 under a Chamber of Mines Research Organization (now the CSIR: Division of Mining Technology) programme of research into the behaviour and benefits of backfill may assist with this situation. The original work was motivated by the premise that the improved hangingwall stability in backfilled panels (identified by rockfall accident analyses) is due to a change in the hangingwall stress regime. Current, largely theoretical, studies into mechanisms of stope hangingwall behaviour and support interaction could benefit from considering these data. Keywords: Backfill, horizontal stress, stope hangingwall, hangingwall stability, support interaction.

Jan 1, 2002

By C. Dinis da Cama

In order to reduce the complexity of mechanisms influencing rock- fragmentation by blasting a simulation approach is proposed, using the capabilities of micro-computer interactive graphics. Situations involving cratering and bench blasting are simulated, and both jointed and intact rocks can be subjected to explosive action, taking into consideration its breakage mechanisms. Size analysis curves relating rock distribution before and after the blasts are determined and compared with field data.

Jan 1, 1984

By Doris M. Hyde

The 350,000-barrel-per-day Bahamas Oil Refining Co remained closed throughout 1986. Financially troubled Charter Oil Co., joint owner of the refinery with Chevron Oil Bahamas Ltd., agreed in principle to have Chevron assume full ownership in return for canceling debts owed Chevron. Finalization of the agreement was pending at yearend. Burmah Oil Ltd. took more than a $30 million loss on the sale of its interest in South Riding Point Grand Bahama Transshipment Terminal to South Riding Point Terminal Holding Ltd.

Jan 1, 1988

By D. Mark Richards

Highland Valley Copper (HVC) is a large open pit copper mine in the southern interior of British Columbia. Machine guidance technology using GPS has been utilized at the mine since 1996 for blast hole drill navigation and since 2000 for shovel and dozer navigation. Since 1997, rock recognition has been part of the drilling process. This allowed the mine to develop a Mine to Mill strategy using the rock hardness information from drill monitoring systems to both refine drilling and blasting parameters as well as downstream crushing and grinding strategies. Although this preliminary effort has been very successful at HVC, the current intent is to gain further benefits through better use of existing information while also deriving an enhanced data set from monitoring production drills. In the latter case, the objective is to acquire and process drill variables in such a manner as to permit more detailed definition of rock mass characteristics. The subsequent focus will be to use the derived geotechnical and geological information as part of a practical process to more prescriptively blast the rock mass. Through the definition of domains based on drill monitored derived rock mass properties, the intent will be to enhance blast outcomes that lead to optimized downstream (from blasting through to concentration) processes in a more proactive and timely manner. This paper examines a proposed approach to be able to derive more accurate and consistent rock mass properties from production drilling. In addition, the discussion will identify potential benefits to be gained from process improvements that result in enhanced productivities, and crushing and grinding optimisation due to blasting strategies that are more closely matched to identify rock mass characteristics.

May 1, 2007

By J. West

For many years line-of-sight (LOS) issues for underground mobile equipment is a growing focus of research. This research is a result of the numerous fatalities and injuries which occur in the mining industry and which are related to poor operator LOS. Three assessment methods are currently used to assess operator LOS of underground mobile equipment. The light filament (LF) method is a hands-on assessment method that is performed in the field. This method is not evaluated in this paper. The laser scan (LS) method of assessing equipment is a quick and reliable method that comes from the need to evaluate vehicles already located in the field. The computer simulation (CS) method can assess LOS issues using a computer aided drawing (CAD) model, which is useful for assessing current or prototype models. The purpose of the current research is to compare and validate different operator LOS assessment methods. Comparison of the results of the LS and CS visibility plots yielded similar quantifiable results. A visual comparison of the results further illustrate that the LS and CS methods are acceptable assessment tools for mobile equipment operator LOS evaluation. The visibility assessment methods are now being prepared as guidelines for the mining industry to assess current and potential designs.

Jan 1, 2007

The Reefton Goldfield on the West Coast of the South Island of New Zealand was a significant gold producing area between 1860 and 1951. During this period it produced approximately 2.1 million ounces (67 tonnes) of gold. The largest single producer on the goldfield and the deepest mine in New Zealand, was the Blackwater Mine at Waiuta which produced 21 tonnes of gold. The Prolubition Shaft reached a depth of 878 metres (317 metres below sea level). The mine closed suddenly in 1951 with about 66 000 tonnes of are remaining in the stapes. Since closure there has been no attempt to determine the ore potential of the mine at depth. This paper summarises the geology, history and resource potential of the mine and sets out two options for evaluating the remaining resource. The options are either deep drilling from surface or recovery of the Prohibition Shaft and underground development and drilling. A schedule for each option is presented and discussed.

Jan 1, 1992

By K. P. Kavun, M. N. Denisov

Discussed in the paper is the redesigned reserve/resource classification for solid minerals being put forth by the authors to replace the acting Russian classification of 19961. The new version is based on the traditional foundations of former Russian classifications and the principles of the ‘McKelvey box’, both categorizing mineral resources according to the degree of geological assurance and economic viability. Based on these approaches the classification deliberately deals with both reserve and resource categories very similar to those established by the Geneva Accords in terms of definitions implied. The authors proceed from the UN-ECE proposed concept of ‘reserves’ being a part of ‘total resources’ explored in great detail by geological and feasibility studies and economically mineable at the time of reporting. The draft classification distinguishes ‘proved’, ‘probable’ and ‘possible’ categories of reserves depending on the stage of feasibility assessment carried out, i.e. the degree of detail and accuracy with which modifying factors affecting mineability of an orebody are taken into account. The reserves are regarded as a product of feasibility assessment of ‘measured’, ‘indicated’ and ‘inferred’ resources. The portions of them not having been classified as ‘reserves’ are regarded as composed of two classes: ‘subeconomic’ and ‘potentially economic’ resources (or ‘resource base’). All the cells of the classification matrix are provided with traditional for Russia alphanumeric designations and appropriate UNFC codes. The classification scheme recommended is viewed as a step forward in improvement of the State inventory and reporting mineral resources in market conditions, conducive to cross-border professional collaboration in the field of providing reliable information on the mineral rawmaterials base of the world’s economy. Besides, it recommends an easy way to get rid of amethodological error in the UNFC classification scheme where consecutive stages of geologicalexploration are identified with a single inherent degree of geological assurance. Keywords: mineral resources, mineral reserves, classification, geological assurance, feasibility studies, subeconomic resources, undiscovered resources, competent person.

Jan 1, 2003

The Detachment of Coarse, Composite Particles from Bubbles

Sep 13, 2010

By K. K. Kershner

The purpose of this investigation was to develop methods, on a laboratory scale, for recovering tin from Bolivian metallurgical slimes. Petrographic and chemical analyses were made of slime ore fractions from several well-known tin operations. High percentages of the total tin were volatilized as chlorides at temperatures below 600° C. Under optimum conditions reaction rates were relatively rapid, and the chloridizing reaction approached completion. Owing to the low temperatures involved and the high yields of tin, the process was considered to have possibilities for treating Bolivian slimes on a commercial basis. ACKNOWLEDGMENTS Appreciation is hereby extended to the Patino Mines and Enterprises, Inc., of Bolivia, for supplying slimed tin ores that were used in the experimental work. This company has since been nationalized.

Jan 1, 1959

By Alexander Sutulov

El presente texto señala la importancia del beneficio de minerales sulfurados y oxidados de cobre a través de dos apartados: Los aspectos generales y la mineralurgia del cobre. Los primeros comprenden la disminución del contenido fino de las menas, materias primas complejas, aumento de escala, control automático y planta del futuro. Mientras que el segundo, describe la flotación de sulfuros, el proceso de segregación, tratamiento de óxidos, métodos hidrometalúrgicos y la lixiviación bacteriológica.

Nov 20, 1969

Drilling at Ipswich during the last twelve years by the Queensland Department of Mines has proved large quantities of reserves which have assured the security of the field for many years to come. This is perhaps the greatest contribution to the development of the field since its discovery in 1827.The drilling campaign commenced in 1950 and by the end of 1961 comprised 242 holes totalling 180,220 ft.Intersections of formations and seams, accompanied by detailed surface mapping, led to more precise knowledge of the geology of the field than was previously possible, and clarified many problems of correlation. Productive formations are part of the Middle Triassic Ipswich Coal Measures, a 4,300 ft sequence of fresh-water sediments with some interbedded volcanics. They are overlain by the Upper Triassic Bundamba Group and the Lower Tertiary Booval Group.Reserves disclosed by drilling amount to 171,487,000 tons, comprising 109,407,000 tons "measured" and 62,080,000 tons "indicated". The security of these reserves encouraged many collieries to instal modern efficient mining machinery and washing plants.The climax of recent development of the resources of the field will be the commissioning in 1966 of a £33 million 360 MW power station in the Swanbank district which will consume 14 million tons of coal during its 30 year life and will have a peak demand of some 20,000 tons per week.Drilling is continuing and is expected to prove additional reserves which will justify further development of the field.INTRODUCTIONUntil 1949 there had been no concerted effort to test systematically the resources of the whole Ipswich field. Fifty two known holes totalling 30,500 ft had been drilled, eight of them by the Department of Mines, but because of poor core recovery and inadequate records most of them were of little use in a comprehensive assessment.Development of the field was being retarded by uncertainty regarding reserves and by the general state of the coal mining industry. Numbers of comparatively small independent companies and owner groups were operating coal...

Jan 1, 1963

By J. C. Detweiler

THE Jacksonville plant of Humphreys Gold Corp., operating under leases from National Lead Co. and Rutile Mining Co. of Florida, recovers rutile, ilmenite, zircon, and monazite from an ancient beach deposit containing about 2.5 pct of these minerals in combination. The location of the plant is unique, being situated about ten miles from the center of Jacksonville, Fla., surrounded by a thriving suburb. Two four-lane highways pass within 1 ½ miles of the plant. An expressway now under construction will pass over the tailing pile, within 500 ft of the mine office. The elevation at the plant site is approximately 50 ft above sea level. This is one of two mines producing titanium minerals and zircon in Florida. Another mine is also operated by Humphreys at Starke, about 50 miles southeast of Jacksonville. The Jacksonville deposit extends about six miles in a north-south direction, averaging approximately one half mile wide and twenty ft thick. Values begin at the surface over most of its length and ter-

Jan 1, 1952

As a part of its overall wealth in fuel resources, the United States possesses large reserves of coal of ignite rank. According to recent estimates of the Federal Geological Survey (3, 5),l/ the assured lignite reserves of this country amount in total to over 463 billion tons, equivalent to 24 percent of our total national coal reserve on a tonnage basis and 15 percent on a heating-value basis. Distribution and relative amounts of United States coal and lignite reserves are indicated in figure 1. By far the largest proportion of our lignite reserves, over 95 percent is found in North Central States, principally in North Dakota, South Dakota, and Montana, in the vast coal-bearing structural grouping designated as the Fort Union formation. Of the remaining United States reserves, all but a fraction of 1 percent are found in a series of relatively scattered deposits in Texas.

Jan 1, 1954

By Mark S. Stagg

Blast-induced ground vibrations from surface coal mine, quarry, and construction blasting were measured and analyzed for frequency content and duration characteristics. Eighteen commercially available ground vibration measurement systems were evaluated in the field and laboratory for linearity, accuracy, and crosstalk. Buried, surface, and sandbagged transducer placement methods were compared, along with peak and vector-sum measurements. The recommended minimum frequency ranges for ground vibration instrumentation are 2 to 150 Hz for coal mine and quarry blasting, and 5 to 200 Hz for construction and excavation blasting. When higher or lower frequency vibrations are possible, as in construction blasting or for a quarry shot close to a residence, care should be taken to insure proper choices of instrumentation and vibration criteria. Several instruments operating in these ranges are available, and all but one of the seismographs tested fell within ±3-dB accuracy limits (+41 pct, -29 pct). Waveform recordings of all three ground vibration components are recommended as the peak amplitude and frequency may vary among the three. Peak or vector-sum readings are adequate if only amplitude levels are desired. The soil density matched box should be anchored or buried, particularly for high-frequency, high-amplitude construction blasting.

Jan 1, 1980

By Ken Goering

"Bridgestone Americas opened the company’s first U.S.-based giant off-road radial (ORR) tire plant in November. The 139,000-m2 (1.5 -million-sq ft) plant, located on a 222-ha (550- acre) site in Aiken County, SC, will produce radial tire products, including 157-cm (63-in.) tires, used on mining and aggregate haul trucks.The plant, announced in 2011 as a $970-million investment, represents the largest investment that Bridgestone has made in the United States, and is also the single largest investment ever made in South Carolina. Although it had already been producing tires for a few months, the plant officially opened with a ceremony in November 2014, attended by South Carolina federal, state and local elected officials, as well as Bridgestone personnel from the United States and Japan. Prior to the Aiken County plant’s construction, all of Bridgestone’s giant ORR tires were manufactured at its Shimonoseki and Kitakyushu facilities in Japan.Kurt Danielson, president of Bridgestone’s U.S. & Canada Commercial Group, said the facility was built to primarily serve the North American mining and aggregate industries in a more efficient manner. "It’s a real change for us," he said of the U.S.-based plant at its opening ceremony. "This allows us to have a true global presence."The Aiken County plant is intended to allow Bridgestone to meet customer demand for ORR tires, Danielson said. "It really frees up our other plants in Japan to service the rest of the world, allowing us to serve our customers faster," Danielson said. "As soon as we build (a tire), we can have it to our customers."Tires manufactured at Bridgestone’s Japanese plants could spend up to a month in transit to the American continents; from initial mixing of the rubber and other compounds to being warehoused, tires manufactured at the Aiken County plant can be ready to ship in four to five days.Danielson said most of the tires built in Aiken County will be used by customers on the American continents. "We will export," he said, "but our desire is to use as much capacity as we can for the Americas."Ground was broken for the facility inSeptember 2011, when commodity prices were much different than today and global demand for tires had skyrocketed."

Jan 1, 2014

By James H. Cobbs

The utilization of large diameter drilled holes for mine shafts seems to have had its beginning in Europe about 1850 (28) where the mining industries of Germany and The Netherlands first used drilled shafts. Recent shafts in softer formations of diameters as large as 25 feet and as deep as 1, 700 feet have been drilled in both The Netherlands and Germany. The first shaft drillers utilized cable tool or churn drilling techniques which limit both hole diameters and drilling speeds. Though some churn drilling of shafts is still performed, rotary drilling has been the dominant technique for many years.

Jan 1, 1973

By Carl-John Grävare

This paper deals with some of the systems and equipment that are being developed and/or are in use in Scandinavia. The main subject is the development of loading tests on the piles using monitoring equipment. This paper also describes ground improvement using lime-cement columns, expander body piles and steel core piles.

Jan 1, 2000

By Jack L. Taylor

As expected from similar crystal structures and favorable atomic size factors, titanium, vanadium, and molybdenum are completely soluble in one another above the transformation temperature of titanium. The fl phase parameters of the continuous solid solution are shown graphically. Limiting compositions for retained fl phase have been determined. VANADIUM and molybdenum both have body-centered-cubic structures at all temperatures and, from the atomic diameter comparison factor, 3.9 pct, would be expected to form a complete series of solid solutions. The existence of complete solubility has been confirmed by work' at the Jet Propulsion Laboratory. Furthermore, vanadium and molybdenum have favorable atomic size factors to form complete binary solid solutions with the B phase, high temperature form of titanium, which also has body-centered-cubic structure. Pietro-kowsky and Duwez' and Hansen et al." have established the existence of the complete series of solutions in these binary systems. It would be logical, therefore, to expect that p-titanium, vanadium, and molybdenum would be completely soluble in one

Jan 1, 1957

By J. E. Bernick, J. Davies

This paper describes the design and construction of a 22.86 m (75 ft) long jacked tunnel, which was successfully installed, despite difficult mixed face conditions at Metro-North’s Westport Station, in Connecticut in the fall of 2003. The tunnel utilized what is believed to be, the first application of a steel grillage system within the United States. This grillage was installed before the jacking started and allowed the tunnel to be jacked under four live railway tracks, which included the Acela high speed line, without affecting train operations. The clearance between the top of the tunnel and the rails was only 0.9 m (3 ft).

Jan 1, 2005

By Frank Rausche

Without doubt, driven piles are the most economical deep foundation element for a nearshore environment, providing for high bearing capacities and stiffness, quick installation times, assured quality by simple monitoring and inexpensive dynamic load testing during restrike testing. However, when the pile top elevation is several meters below water surface, questions often arise as to the most reliable and economical pile installation method. Frequently encountered, yet relatively expensive, solutions include driving inside a dewatered cofferdam, driving long piles that are later cut off below water surface, or using an underwater hammer. Arguably, the most economical solution is driving the piles with a follower or chaser. However, many foundation engineers shy away from this solution because of the uncertainty associated with the transfer of energy through the interface between follower and pile, the associated potential driveability problems and maybe the limited fatigue life of the follower. This paper will demonstrate how the driveability of a hammer-follower-pile-soil system should be analyzed prior to installation and how to model the pile-follower interface both for steel and concrete piles. As an example, results will be presented which were obtained for both steel pipe piles and precast concrete piles, driven by a single-acting diesel hammer through a steel follower for a pre-construction test pile program in Venice, Italy. While analysis of the steel pile-follower system was straightforward, for the concrete piles, the presence of a soft cushion material whose material properties changed continuously posed some difficulty. Pile Driving Analyzer® measurements and CAPWAP® analysis yielded not only realistic stresses and transferred energy values in the pile, but also reasonable model parameters for further use in a pure wave equation analysis. As a side note for clarity, the dynamic measurements and analysis results herein presented are based on the GRLWEAP and CAPWAP software. GRLWEAP is commonly used all around the world for the preparation of pile driving jobs. The program either yields a bearing graph that relates bearing capacity and pile stresses to blow count or set per blow or it predicts blow counts and pile stresses as a function of pile penetration. These results allow the contractor to estimate driving time and select an economical hammer and driving system for a safe and efficient installation. CAPWAP on the other hand is the analysis of choice once a pile has been installed and records of pile top force and velocity have been acquired during installation or during a restrike test. CAPWAP is a signal matching program which calculates for one particular impact (for example at the end of driving) the static and dynamic soil parameters. Its final results include the calculated resistance distribution, the complete stress history in the pile and also a simulated load set curve. The CAPWAP calculated dynamic soil parameters can also be used in a Refined GRLWEAP analysis to generate a calibrated bearing graph."

Jan 1, 2006