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By A. Mahmoudkhani

Primary cementing is the process of placing cement in the annulus between the casing and the formations exposed to the wellbore. Portland cement was first used in 1903 in the Lopoc Field in California for well cementing. Since then, the major objective of primary cementing has always been to provide zonal isolation in oil, gas and water wells, i.e. to exclude fluid(s) in one zone from another zone in the well. To achieve this objective a hydraulic seal must be created between the casing and cement and between the cement and the formations, while at the same time preventing fluid channels in the cement sheath. This requirement makes primary cementing the most important operation performed on a well. Without complete isolation in the wellbore, the well may never reach its full producing potential. The industry knowledge on cements relies heavily on empirical data, but the chemistry, physics and structure of cement are not fully understood yet. The strength of concrete can be increased essentially by reducing its porosity through optimizing the size distribution of its components and filling the residual porosity of the hydrated cement phase with inorganic fillers. This approach has successfully utilized in different ways and several technologies for placing high performance oil and gas well cements have been developed over the last few decades. There are reasons to believe that the next source of improvement will lie in the fine-tuning of the hydrates themselves and of the different parameters that drive short (ionic?covalent bonding) and long (ionic correlation) interactions.

Jan 1, 2012

By S. A. Aye

Vibration levels on a variety of equipment in a South African opencast mine were measured in this study. The well-established ISO 2631-1 (1997) standard methodology was used for the computation of weighted root mean square (WRMS) and vibration dose value (VDV). This method was used to evaluate the whole-body vibration (WBV) on a wide range of equipment in the opencast mine using the two main parameters, namely the daily exposure A(8) which is based on the WRMS concept and the VDV which measures shocks. The results obtained show that while the majority of the equipment rendered exposure levels that are below the exposure limit value (ELV), exposure levels on about half of the equipment do exceed the exposure action levels. The study also highlights the importance of shock in the observed responses.

Jan 1, 2011

The STATE MINERAL SUMMARIES publication provides estimated data and summaries of mineral activities at the State level for 1989. Most of the estimates are based on nine months data. These summaries have been prepared in cooperation with State geological surveys or related agencies. Individual State summaries are published separately as State Mineral Industry Surveys and copies can be obtained from the appropriate State Activities field office.

Jan 1, 1990

By William D. Hissem

While much technology has been developed and brought to bear in the area of blasting applications, the foundation work required for success in the muck pile begins with the drilling program.

Jan 1, 1997

Whilst the wider community is both a large consumer of mineral products and relies on mineral exports for much of the wealth which sustains it, the community generally has a poor perception of the minerals industry.   The role of professionals and The AusIMM in the "New Economy" minerals industry is reviewed. The new structure of The Institute is vital as we move forward in times of globalisation, rationalism, increasing litigation, criminalisation of risk and increased focus on corporate governance. This address looks forward to ways The AusIMM and professionals of the future are positioning themselves for these and other challenges.

Jan 1, 2001

THE 125th meeting of the Institute was held in New York, Feb. 20-23, 1922, inclusive, and was the most successful annual meeting of the Institute ever held; there was a larger registration, there were more sessions of importance, and a greater number of sessions, than in any previous year. The total registration was 1331, comprising 351 New York members, 393 visiting members and 587 guests. At the annual business meeting of the Institute, held on Tuesday, Feb. 21, with President Ludlow presiding, there was a much larger attendance than usual. The report of the tellers was read and the following officers were declared elected: Arthur S. Dwight, Director and President-District 0 J. V. W. Reynders, Director and Vice-president-District 0 A. R. Ledoux, Director and Vice-president-District 0 Charles F. Rand. Director-District 0 George D. Barron, Director-District 0 William H. Bassett, Director-District 1 Thomas B. Stearns, Director-District 8 William Kelly, Director-District 5

Jan 3, 1922

By António A. Henriques, António Gomes Correia, Ana Teixeira

"Abstract Pile foundations are often used for important structures, and thus, reliability evaluation is an important aspect of the design. Reliability methods have become increasingly important as decision support tools in different areas. The main benefit of reliability analysis is that it provides quantitative information about the parameters (uncertainties) that most significantly influence the behaviour under study. In particular, the design of pile foundations still involves many limitations and uncertainties, particularly when there is not enough investment in soil characterisation and/or pile load tests. In addition to the uncertainties associated with soil characterisation, physical, statistical, spatial and human uncertainties exist. In this subject, the primary purpose of this paper is to demonstrate the application of reliability methods to geotechnical pile design (axial load). It also presents a simple and practical approach to performing it using Monte Carlo Simulations, intending to provide knowledge for code harmonisation and encouraging the development of such methodologies in geotechnical practice. Sensitivity analyses are shown to understand the influence of each uncertainty type coming from different sources. An application example indicates, corroborating other studies, that the model error is the most influent uncertainty. As such, when using the different models (SPT-, CPT- and PMT-based) for bearing capacity, the results emphasise the need for a well-defined and wellcharacterised resistance model, also these results allow the engineer to understand how important the load tests can be to achieve reliable results and economic designs.1 IntroductionUnlike the approach to reliability evaluation used in structural engineering, the traditional procedure used in geotechnical designs addresses uncertainties through high global or partial safety factors (SF), mostly based on past experience. However, this approach to addressing uncertainties does not provide a rational basis for understanding their influence on design.Furthermore, the new regulation codes and social concerns, such as the sustainability or the economy, are imposing geotechnical engineers to increase their ability to deal with uncertainty in a direct and more rational way. Designs should be economic, sustainable and reliable at the same time. Concerning the reliability part of design, different approaches can be done, but the most important thing to keep in mind is the simplicity and efficiency of the tools and applied methods."

Jan 1, 2014

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 S. S. Peng, C. T. Holland

Mountain Top Removal (MTR) mining started in West Virginia nearly thirty years ago. This surface mining method can extract multiple coal seams as thin as a few inches thick with total recovery and minimum rock dilution in very steep mountainous terrain. It is highly efficient even if coal seams are in close proximity and small in aerial extent. Consequently, MTR has been widely used in the Central Appalachian Coalfield (mainly Kentucky, Tennessee, Virginia and West Virginia) for the past thirty years with great success. In that respect, there has been no demand for research and little scientific research has been performed to investigate its impacts on the surroundings in the history of MTR mining. However, in the past two years the debate over the MTR mining has grown quickly and in times become very intensely. This paper describes chronologically the issues raised by various parties, legal actions, its impacts on mining permit application and research projects developed to address the issues.

Jan 1, 2000

By H. A. Bilgin, G. G. U. Aldas

"Ground vibration is the natural result of the blasting process. Many empirical formulae and methodologies including analysis of travel path effects have been developed. The scaled distance, which is the most popular approach for the calculation of the attenuation of particle velocity in the ground, has led to significant advances in the prediction of particle velocity when both explosive charge and distance vary. However, this approach does not consider the effect of ground anisotropy and existence of structural geological features on ground vibration. Therefore, in this study, the effects of these rock mass properties on types, amplitudes, and frequencies of ground vibration waves at four surface mines are examined. The results, which were implemented at Kangal coal mine, Bastas quarry and Kíbrís quarry, provided guidance for the extensive study at Orhaneli surface coal mine.As a result of the study, the authors came to the conclusion that vibration amplitudes change depending on the ground on which sensors were deployed and the conditions depending on whether measurements were done near major structural geological features. It was determined that the vibration amplitudes, measured at equal distances from the source but in different directions, change because of the propagation velocity anisotropy. Besides the change of wave type due to the kind of ground at the measurement location, it was determined that vibration anomolies were due to structural features."

Jan 1, 2004

By Louis J. Cabri

"Mineralogical evaluation of ores containing platinum-group elements (PGE) is fraught with difficulties because of the low grades (often 1-3 g/t PGE), dispersal of PGE (usually as finegrained platinum-group minerals [PGM]), as well as occurring in solid solution in some base metal sulphides (BMS) such as pentlandite and pyrrhotite. Mineral processors not only need to know how the PGE are distributed, that is, their mineralogical distribution, but the grain sizes of the PGM, and especially the associated minerals.After obtaining a representative ground sample, common approaches include studying a large number of polished or polished thin sections, concentration of the PGM and sulphides by different gravity methods (e.g., heavy liquids, elutriation, micro-panning) and study of the produced concentrates. Unfortunately, these methods often do not produce concentrations that are sufficiently representative of a particular ore. The newly developed patented technology of hydroseparation (Rudashevsky et al., 2002) is especially effective at making concentrations of PGM over a wide range of concentrations (down to <300 ppb Pt+Pd+Au) and size fractions, including <45µm (down to a few micrometres in size), a size range not possible by other techniques. This water-based environmentally friendly laboratory technique provides a large amount of data from samples, which can range from 5 to 1000g, giving confidence to extrapolation of results to bench-scale and larger test work, especially when combined with quantitative image analysis to determine modal percent of major minerals and mineral liberation data, needed to predict the minimum (K80) and optimum (K40) grinds. INTRODUCTIONThe invention of the electron microprobe in the early 1960’s and scanning electron microscopes (SEM) with energy dispersive spectrometers (EDS) in the 1970’s presented mineralogists with powerful tools permitting them to obtain chemical and surface area data on minute amounts of minerals in situ, in a non-destructive manner. An area of process mineralogy that has very much benefited from this new technology was the characterization and understanding of PGM species, resulting in rapid growth of newly characterized species (Figure 1). Recognition of the first PGM may be ascribed to the Spanish explorer Ulloa in 1748, who described native platinum from South America. The second PGM (laurite, RuS2) was only recognised in 1866 by Wöhler in placer samples from Borneo (now Kalimantan) and the third (sperrylite, PtAs2) by Wells in 1889 from the Sudbury Ni-Cu sulphide deposits. The discovery of the important Pt-Pd deposits in the Bushveld Igneous Complex led to the characterization of the important Pt-Pd sulphides (cooperite, PtS2 in 1928 and braggite, (Pt,Pd)S2 in 1932). By the early 1960’s, only about 20 PGM were recognised, and many later proved to be poorly or incompletely characterized. Thus, the introduction of electron probe microanalysis (EPMA) led to a 50% increase of known PGM, as shown in a 1972 review on PGM (Cabri, 1972). At the time of the next review in 1981 (Cabri, 1981) the number of known PGM had grown to 75 and as of 2002, it had increased to 109 (Cabri, 2002). However, it is the author’s experience that less than about 25 PGM may be considered to be “common”, i.e., found in many different deposit types, as shown in Table 1, but usually only some of these occur in any one particular deposit."

Jan 1, 2004

By Eric R. Borys, Amaneh E. Kenarsari, Brett Gitskin

This case study discusses impacts of excessive Earth Retention System (ERS) lateral movement at a project in city of Chicago. The ERS (cantilevered sheeting) moved inward towards the excavation and caused lateral displacement and cracks in six drilled shafts located about 1 to 2 lateral feet (0.3 to 0.6 m) from the face of the sheet pile wall. Up to 9 inches (23 cm) of horizontal movement was observed on top of the supporting sheet-pile. Similarly, survey measurements showed the top of the drilled shafts moved laterally up to 8 inches (20.3 cm). To evaluate the cause of failure and determine a remediation solution, the soil, shaft and site conditions were investigated. Pile Integrity Tests (PIT) were conducted at the affected drilled shafts. The shafts with identified anomalies were cored and video-recorded. The cause of the failure was determined to be related to variable soil conditions across the site, deeper excavation (i.e., increased effective ERS wall height), and other differences between design and as-built conditions. Internal bracing, in the form of walers and rakers, was installed to limit further movement of the sheet pile as a short-term solution, with additional grade beams framed into the basement slab-on-grade as a long- term solution. Five of the six cracked shafts were spliced with reinforcing bars and high strength grout and one shaft was replaced. INTRODUCTION The subsoil in the Chicago Area mostly consists of glacial till clays underlain by water-bearing granular soil over bedrock. The glacial clays have very soft to medium consistencies for a typical thickness of 30 to 50 feet (9.1 to 15.2 m) below which hard clays (Hardpan, i.e., heavily over-consolidated clay soils) are encountered. The soft clays are often referred to as the “Chicago Blue Clay”. Beach Sands are also found above upper soft clays in several areas, especially within a three-mile strip near Lake Michigan (Peck and Reed 1954). Due to the existence of soft clay in Chicago area, supporting the mid to high rise buildings on drilled shafts extended to Hardpan is a common practice in modern building design. In the early 19th century it used to take about 3 weeks to excavate 1 shaft hole and about 1½ days to fill the shaft with concrete in Chicago (Manierre 1916). The early 19th century methodology of excavating a shaft consisted of hand digging the shaft, installing wood lagging as temporary shoring with spoils removed with a rope and pulley system from the surface. Today, the excavation of a typical drilled shaft in Chicago uses heavy drilling equipment and requires much less time for excavation and concrete placement. It is not uncommon for contractors to excavate shafts and place concrete at a rate of about 2 to 5 drilled shafts per day (with one drill rig).

Jan 1, 2018

By G. Bierie

The conveying of bulk materials is prone to problems. These problems can reduce the capacity and efficiency of the plant, and even threaten the health and safety of the workforce. This presentation will look at new conveyor technologies systems, and how, used separately or in combination, they can improve material handling.

Jan 1, 2007

By G. L. Oldright

In an earlier series of 15 Reports of Investigations on Smelting in the Lead Blast Furnace, experimental data were given on the operations of a custom smelter, a smelter treating rich lead products, and a smelter treating highly zinciferous charges. Five "reports" were written on each of the three types of operation, which were later compared in a summary written for the Institute. Developments in each of these types of operation in lead smelting since the last of the above reports was written have continued and have followed modifications necessitated by changes in the nature of the products received for smelting. The sintering-blast furnace-smelting plants have improved their sintering operation .and have made "2-pass" sintering a more standard operation; the richer lead feeds are diluted when marginal precious metal ores are not available to prevent fusion of the sinter cakes and to permit air to contact the sulfides. Means have been devised to make it easier to remove metallic lead from the wind boxes, but no attempts have been observed to use the D & L somewhat as an ore hearth to make more metallic lead. Except in those cases where zinc-rich lead blast-furnace slags were to be retreated in a "slag-fuming furnace," the sintering and the blast-furnace operations were so carried out that a relatively "clean," lead-poor, final slag was discarded.

Jan 1, 1949

By A. W. Asman

The problem of balanced design in a belt conveyor has been under constant study. Increased use of this method of transport in recent years has stimulated investigations. Conveyor belt, power transmission and other machinery should be adequate to perform the required service. All components of the belt conveyor should work as an efficient unit moving its load continuously between terminals. As part of a long term research project on belt conveyors, Hewitt-Robins established in 1954 a 2-year grant at Pennsylvania State University. Under terms of the grant, certain fundamental phenomena were to be studied. This work evolved a new concept in belt conveyor power determination based on the principle of belt tension. The Penn State contract furnished the foundation for later more detailed studies. From these most recent investigations, more specific factors were defined. In the final analysis, all of the data collected has been worthwhile in belt conveyor design. Units now operate over long distances at speeds of over 800 fpm. Long high lifts are commonplace. Where vertical or inclined shafts were the rule, belt conveyors receive first consideration. Although belt conveyors have moved forward rapidly, the future will see a tremendous gain in their use. The ideal test belt conveyor would be several thousand feet in length and have a maximum tension of at least 70,000 lb., Also, this conveyor should be horizontai and have a variable feed rate of more than one material. Data from such a field belt conveyor combined with laboratory information would permit accurate analysis. Since this type of conveyor was not available, many field locations were visited: An alternate would have been to erect a closed circuit system in the laboratory. Either method had limitations and the first was selected as having the best possibilities. Manufacturers of conveyor belting and machinery basically have been using the same horsepower formula. As more information became available from field installations, factors in the basic formula were modified. Practically all conveyors are designed today by adding together the horsepowers required to move the empty belt, move the load horizontally, and elevate the load. In selecting size of drive motor, the first two elements are relatively unimportant if the last is large. However, it is the combination of

Jan 1, 1961

By Lee T. J

The area, A, under a gamma-ray log that passes through a horizontal bed given by: A = gl/k. Here is the equivalent concentration of U3O8 in the body, l the thickness of the body, and k the calibration factor or sensitivityof the logger. The area is independent of the logging speed or logger time constant.This relationship, together with the first moment about the maximum of the log and its value there suflicient to determine the thickness, position of the centre of the bed from the log maximum and the concentration of U3O8.Numerical results obtained from artificial and field data show that the computed results arc as good as those obtained by methods such as the inverse filter technique and the iterative method. The present method yields results that arc easier to feed into an ore reserve data base.

Jan 1, 1981

By B. Anameric, S. K. Kawatra, K. B. Rundman

The iron nugget process is an economical, environmentally friendly, cokeless, single-step pig iron making process. Residence time dependent process requirements for production of pig iron nuggets at a fixed furnace temperature (1425 C) were investigated. Three chemically and physically different products were produced after complete reduction to iron, depending on the residence time in the furnace. These products were direct reduced iron (DRI), transition direct reduced iron (TDRI), and pig iron nuggets (PIN). The increase in the carbon content of the system as a function of residence time was detected by optical microscopy and Microhardness measurements. Sufficient carbon dissolution for the production of pig iron nuggets was obtained after 40 minutes residence time. The pig iron nuggets produced had chemical and physical properties similar to blast furnace pig iron. They were liquid state products and slag was completely separated from the metal.

Jan 1, 2005

By H. Gurgenli

Mining companies require accurate short-term mining forecasts to meet budget targets and customer needs. Challenging mining conditions along with employee turnover and lack of standard geologic modeling and mine planning processes can result in time-consuming and inconsistent mine plans. Documentation and automation of the processes involved in mine planning, as well as proper software utilization, are critical in overcoming these challenges. This paper discusses the steps involved in achieving an optimized mine planning system to accomplish productive and cost effective operations. In addition, a case study is included to describe the process of implementing a semi-automated system whereby the geologic model and mine scheduling database are updated monthly to incorporate changes in geology in a relatively complex open-pit coal mine. This case study proves that the ability to update geologic models based on the latest information gathered from production drilling and mining activities can greatly enhance the ability to accurately predict short-term mining production.

Jan 1, 2011

By Ralph E. Burnham, Jeff Taylor, Jonson Montgomery, J. Kelly Ratliff, Rennie Montgomery, Martin Brashear

Top priorities for all blasting companies and individual blasters are risk management, safety of company personnel and the general public, regulatory compliance, and liability protection. On a daily basis, hundreds of shots are detonated by well-trained, skilled, and experienced blasters without incident. Unfortunately, accidents inevitably occur, which is why blasting is considered an “ultra hazardous” or “inherently dangerous” activity from a legal perspective. Despite countless regulations, recent advances in technology, improved training, ongoing research, and improved communication in the industry, mistakes and the resulting incidents continue to occur during blasting operations. These result in dangerous or deadly flyrock, site security lapses, increased complaints, blast damage claims, and lawsuits, which lead to increased insurance costs and other financial tolls for blasting companies. In life, lessons learned the hard way are rarely forgotten. The same is true in blasting operations. Blasting missteps and the resulting events are often the best catalysts for improving risk management and thereby reducing accidents, liability, and financial tolls. This paper provides a summary of two incidents, one safety and the other liability related, and the errors that resulted in a fatality in one case and a multi property lawsuit in the other. The two incidents provide examples that serve as a case study for lessons learned the hard way in blasting operations and offer guidance for the considerations that blasters and blasting companies should incorporate into daily operating procedures.

Jan 1, 2018

By Andrew L. Peterson

CATOH Inc. of Weedsport, New York recently completed a very challenging Bored-In Pile project which features unique construction techniques in the installation and load testing of 45 and 100 ton capacity piles. The bored-in piles were installed on a twenty-nine million dollar New York State Department of Transportation project which began in the fall of 1995 and ended in March of 1997. The project included the construction of 5 new bridges to alleviate a very congested traffic network which had come to be known as the "Octopus" in the small city of Ithaca, New York. CATOH Inc. was awarded the piling contract by general contractor Santaro Industries in the fall of 1995. Piling installation work was completed in March of 1997. BACKGROUND The project is located at the southern tip of Cayuga Lake which lies in the heart of Upstate New York&apos;s Finger Lakes Region. This region is popular not only for wine making and vacationing, but also for its impressive geological history. The glacial activities that helped to form the deep valleys of this scenic area are also responsible for creating challenging underground conditions for deep foundations work. CATOH developed two pile designs to accommodate differing site conditions on the project. Internally reinforced piles were developed for use in the center of the valley and externally reinforced piles were developed for locations close to the valley wall.

Jan 1, 1997