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By Sukumar Bandopadhyay

In recent years, research in the field of artificial intelligence (AI) has had many important successes. Among the most significant of these has been the development of powerful new computer software known as the "expert systems". Expert system programs designed to provide expert-level consultative advice in mineral exploration (Duda et al, 1981), scientific (Feigenbaum, Buchanan and Lederburg, 1971) and medical (Shortliffe, 1976) problem solving are generally acknowledged to be among the forerunners of this research. As the decision makers virtually in all fields face a more complex and involved world within which to operate, the need for some decision support is also becoming urgent. Thus applications of expert systems continue to spread out reaching problems that, because of their dimensions or particular aspects, set more demand on the decision methodologies. To meet these new requirements, many activities which were performed in the past by the domain expert or engineer must become automated. Furthermore, previous research (Dawes and Corrigan, 1974; Dawes, 1979) has shown that automating an expert's decision rules often provide better decision than the expert does. For large systems it would be very useful (or even necessary) to have formal tools, allowing one for example, to automatically discover inconsistencies, contradictions or redundancies, or to identify the possibilities of wrong lines of reasoning in the decision process.

Jan 1, 1990

By Luis Alva Saldaña

"Actualmente el método para descubrimiento de nuevos procesos y la elaboración de nuevas técnicas se ha modernizado. En ese sentido, el presente artículo señala la invención de estos procesos y técnicas a través del estudio de la Termodinámica. Esta ciencia trata de las relaciones entre las diversas formas de la energía, mostrando cuantitativamente los efectos que experimenta el complejo materia-energía cuando en él se realizaalgún cambio. Por ello, es fácil observar que muchos laboratorios tanto de Europa como de los Estados Unidos de Norteamérica, realizan estudios no sólo para completar las tablas de propiedades termodinámicas de las sustancias químicas, ya existentes, sino también para revisar los datos que antes se tenían de éstas."

Jul 1, 1955

By Sastry Putcha, Santosh Mummaneni, Swamy Avasarala, Vamshi Vemula

"This paper presents the results from a case study on the comparison of two strain acquisition instrumentation technologies, Geokon rebar strainmeters and Embedded Data Collectors (EDC) for the DC Water Main Pump Station project, in Washington D.C. These two instrumentation systems were installed by AVER in a single 18-inch (0.45 m) diameter augercast pile (with one-1.25 inch (3.175 cm) dywidag bar) at critical locations to determine the load transfer mechanism and establish a comparison between strain/load measured with these two systems along the pile. A quick static load test was performed on the test pile as per ASTM D1143 standard.Prior to the installation of the pile, a 24-inch (0.6 m) diameter outer casing was installed to the proposed cutoff elevation of -22.5 feet (-6.85 m) to discount the frictional resitance within the upper overburden zone. The pile was then drilled through the outer casing to the tip elevation of -65.02 feet (-19.8 m) with inner casing within the overburden zone. Strainmeters along with EDC were installed on dywidag bar at various locations and then wet set into the concrete following auger retrieval. The loads measured with EDC and Geokon sensors were within 15% percent of each other.PROJECT BACKGROUNDProject Background & Requirements:Like any other foundation piles, augercast piles are extensively used in the public and private sector structures in the United States for many years. It is a common practice to perform static compression (ASTM D1143), tension (ASTM D3689), and lateral load tests (ASTM D3966) depending on the project requirements. In recent years, embedded strain sensors, manufactured by Smart Structures, USA has gained prominence for its use to collect both static and dynamic measurements for driven piles. In addition, AVER has successfully used EDC for collecting long term static measurements for an abutment drilled shafts for I-95 Hotlanes project in Virginia, USA.Geokon sisterbar strain gages are widely used in the foundation industry to monitor the load transfer mechanism within pile foundations throughout the world. As the Geokon strainmeters are vibrating wire and are welded to a sister bar, there is often a debate within the engineering community with regards to what modulus to use when converting measured strains to loads. EDC sensors, unlike Geokon strain gages are embedded directly into the concrete and therefore do not have the same concern."

Jan 1, 1900

By Henry Zhang

This paper presents two case studies of large diameter driven tubular steel piles for the ongoing Woolgoolga to Ballina Pacific Highway upgrade (W2B). This project forms part of Australia’s largest regional infrastructure project and will upgrade about 155 kilometers of highway to four-lane, divided road. There are more than 170 bridges on W2B, and driven tubular steel piles are adopted on 43 bridges between Glenugie and Ballina. Driven piles terminating in soil or basalt is a big challenge faced by both designers and piling contractors due to 1) the uncertainty of expected pile unit shaft and base resistance in different soils; 2) whether plugging is formed; and 3) highly variable basalt strength and thickness near top of the rock. If these risks are not adequately managed during design or construction stages, it could lead to unexpected project delay, extra time and cost or pile toe damage in basalt. This paper describes two case studies, one for piles designed to terminate in soils and the other for piles designed to terminate in basalt. How these risks were assessed and managed during detailed design, procurement, hammer selection, pile installation and verification will be discussed in details with lessons learnt summerised in the conclusion.

Nov 1, 2022

By M. H. Tyeb, C. Banerjee, A. K. Majumder

The primary requirement from a hydrocyclone is the classification of the feed solid particles. Particle classification occurs inside a hydrocyclone by virtue of the relative radial distribution of the suspended particles, based on their size and specific gravity. The particle classification behaviour in a hydrocyclone is experimentally studied in this paper. The phenomenological features of the air core at different feed solid concentrations and the distribution of the solid concentrations in the hydrocyclone are also analysed by the theoretical study of flow features in a steady Rankine vortex. Semi-empirical models for predicting the hydrocyclone performance in terms of flow split ratio, and cut size have been developed using the background knowledge of convoluted hydrodynamics. In addition, to validate the classification performance of a smaller diameter hydrocyclone, the potential of the present model is extended for envisaging the same for larger diameter hydrocyclones. A comparison between the model predicted values and the measurement data shows a good match. Keywords: Hydrocyclone, classification, Rankine-vortex, air core, modelling

Jan 1, 2020

By Wen-long Zhan, Chun-en Zhu, Xiao-dong Du, Yong Zhao, Keng Wu

In view of the traditional evaluation index of sintering basic character- istics ignoring process information, several high temperature characteristic num- bers, which contain process information, were used to evaluate the sintering basic characteristics more comprehensively in this paper. The evaluation model of iron ore properties was established based on the high temperature characteristic numbers with employing fuzzy mathematics. Then, with the constraint of sinter properties and the raw materials, the ore blending model was built, whose target was to obtain the lowest cost and the best sinter properties. A multi-objective fuzzy linear pro- gramming was used to solve the model in order to get the best ore matching schemes. The ore blending model was then applied to the practical production, which was proved to be dependable.

Mar 1, 2018

By W. G. Pariseau

This paper is concerned with the problem of calculating ground movement that occurs as a consequence of mining. Solution to this problem is straight forward in principle but rather complex in practice. The complexities of the problem arise from the ever present constraints of technology and economics. However, the identity of these constraints is often obscured by a faulty understanding of the fundamentals of the problem and a lack of appreciation of current computational capabilities and costs. As a consequence much time and effort are sometimes wasted on gathering information that is of little direct value to ground control programs while important input data are neglected. This paper therefore reviews the essentials of the process of formulating the ground movement problem. Emphasis is upon application to longwall mining, although much of the discussion applies to other mining methods as well. In many instances, the hardrock term stope could be substituted for longwall panel because the fundamentals of the problem are independent of the excavation dimensions and numerical values of rock properties. The latter affect the outcome of a calculation, of course, but not the underlying formulation. Only the major features of the problem are discussed in this brief review. The objective of the discussion is the generation of a reliable basis for developing a technically sound ground control strategy. Any rational ground control strategy must be consistent with basic physical laws. For example, under static conditions, equations of equilibrium must be satisfied. Operational, that is, tactical, details may vary widely with local conditions, but the basic approach must be based on physical laws. The alternative empirical route is intrinsically unreliable and unnecessary as well. Empirical descriptions of ground motion caused by mining including recent statistical curve fits to specialized data sets (for example, surface subsidence data) as well as antiquated "theories" of ground pressure and so forth, however dignified with mathematical formulas, are hardly worthy of the label "theory". Extrapolation of statistical data is always accompanied by rapidly diverging confidence limits, while empirical equations simply lack predictive capability under circumstances even slightly different from those of the original development. For example, applications of surface subsidence curves generated empirically in the United Kingdom to coal mines in the United States generally result in considerably greater subsidence and wider subsidence troughs than actually observed. Locally, empirical criteria for specific ground control actions may be made practical through trial and error, but such tactics are no basis for the development of a general ground control strategy. In this regard, it is worthwhile to recall the traditional scientific distinctions between speculation, hypothesis and law, between the empirical and the proven.

Jan 1, 1982

By Jon G. Bredeson

A survey of electromagnetic noise reports was performed and a summary of the results are given. Industrial concerns were surveyed for techniques to minimize the effects of electromagnetic noise and are presented. The common types of communication links used in mines today are presented. A mathematical development was presented which determines the probability of bit errors versus distance for various types of communication links designed for in mine use. The probability of undetected errors for the protocols of the communication links is given together with burst error detection.

Jan 1, 1981

By W. Murray Small

Nickel plays an important role in determining the properties of many stainless steels and superalloys. Cobalt also contributes significantly to the performance of certain grades of superalloys. A major technical aspect, in which both of these metallic elements are involved, concerns the solubility of nitrogen in these classes of alloys. Beyond certain content limits, dissolved nitrogen may contribute to the deleterious mechanical behavior by these alloys. It is therefore essential to control the level of this element during alloy processing. In this paper, results from several experimental studies have been assembled and are analyzed to describe phenomena related to the individual effects of nickel and cobalt on the solution of nitrogen in several groups of alloys. Both solid and liquid alloy systems are considered. This information may be used as a guide to limit or control the presence of this interstitial element in alloys.

Jan 1, 1993

By Hiroyuki Sano, Chikabumi Yamauchi, Mitsuru Tanahashi, Toshiharu Fujisawa, Shin-ya Iwahori

"Pyrometallurgical process using Cu2O-based slag was proposed as a recycling process for copper scrap. However, it is difficult to remove nickel from copper by oxidative refining. Therefore, it is necessary to reduce the concentration of nickel in copper before the oxidative refining. In the present work, the copper enrichment stage in this recycling process, where copper scrap melt is separated into the Fe-C-Cu melt and the molten copper, was taken up and the compositions of both melts were measured. Based on the above results, the distribution ratios of nickel between the Fe-C-Cu melt and the molten copper were calculated. Furthermore, the optimum condition of copper enrichment stage was discussed from the viewpoint of nickel removal and copper recovery. The possibility of recovering 4N-purity copper by using this recycling process was confirmed.IntroductionRecycling is well known as a method for saving resources and reducing environmental damage. More than 99% of copper is used in metallic form - as metal or copper alloys[l]. High-grade copper scrap is directly re-melted and reused, while low-grade copper scrap is transported to copper smelters to be pyrorefined and electrorefined. Nevertheless, a great amount of copper is being stockpiled in the cities and should be recycled in the near future. At that time, the current recycling process will face new problems due to the increases in the recycling rate to the smelters. This includes insufficient combustion heat to melt copper scrap and ·almost no benefit in electrorefining because the scrap does not contain gold and silver. Thus, an alternative pyrometallurgical method for copper scrap refining will be required."

Jan 1, 2000

By P Voulgaris

The Osborne Mine commenced production from an open pit in December 1994 with the first ore being hauled from underground one year later. Currently all ore is hauled up a decline by trucks until the shaft system is commissioned in early-1998. The mine is hosted within a multiply deformed and complex sequence of metamorphic, igneous and metasomatic rocks of mid Proterozoic age that are concealed beneath 20-40 metres of Mesozoic sedimentary cover. Epigenetic and largely hypogene copper - gold mineralisation occurs in a close spatial relationship with quartz - magnetite ironstones and is an important example of a significant mineralisation style in the Mt Isa inlier. Life of mine concentrator production, to year end 1997, totals 3.2 Mt of ore at 3.40 per cent Cu and 1.13 g/t Au. Total metal produced was 97 000 tonnes of copper and 2900 Kg of gold (95 600 oz) from some 348 000 tonnes of dry concentrates averaging 28.01 per cent Cu and 6.99 g/t Au. At the start of 1998 OsborneÆs total measured and indicated resource was stated at 11.38 Mt at 3.24 per cent Cu and 1.21 g/t Au with an ore reserve of 11.42 Mt at 2.90 per cent Cu and 1.09 g/t Au. Exploration efforts in and around the mine have been increased since 1996 and have resulted in an early success, with a 28 per cent increase in ore reserves since mine start-up, and the establishment of a 1.5 Mt inferred resource open to depth. During 1997 the performance of the concentrator has exceeded expectations with throughput having been increased to 1.45 Mt per annum. The Mining Cycle at Osborne has proceeded from discovery through feasibility and is currently seen to be in the latter part of the development stage and/or the early part of an expansion stage. This paper will describe the role of geology and exploration within these stages and will highlight how a number of key interpretations and decisions based on geology have both favourably and unfavourably affected the project.

Jan 1, 1998

By Henry Callaway

El valor de la mena por explotarse es una cifra importante para la valuación de los depósitos de un distrito minero. Dicho valor comparado con los costos u otros criterios de explotabilidad permite determinar el interés de explotar y explorar una zona, de subsidiar una explotación marginal o de planificar una investigación sobre los puntos débiles del proceso de recuperación. En ese sentido, el presente texto señala los dos métodos adecuado para la explotación de la menas. El primero, considera las leyes porcentuales , los cuales están están indicados por los símbolos químicos de los elementos, mientras que el segundo considera los elementos que forman un concentrado, donde los subíndices aclararán el elemento en referencia.

Nov 1, 1969

By J. M. Dean

With the continued downward pressure on coal selling prices, mine management must make its operations as efficient as possible. The problem is the same one throughout the mineral industries, streamlining operations to maintain competitive mining costs (Born, 1991). There has been a great deal of research into better using production manpower. But the story is different for operations support personnel. Traditionally, planning man-power requirements are done annually, with modifications to the operating plan occurring generally quarterly. On the other hand, the demands on manpower are often dynamic, being responsive to changing productivity levels ,mine conditions (including water influx, bad roof, poor floor)and unanticipated project requirements (responses to machine breakdowns or a new section setup requirement because of a drop in coal quality in another area). Such changes may impact the manpower structure significantly. At times they may cause serious labor relations problems concurrently. Realignments and the generation of instability in the workforce because of active job switching (bidding) are a result. Most responses by coal operators are reactive rather than proactive, a situation that could be mollified by more accurate and detailed planning of predictable manpower requirements. A manpower planning tool is needed that takes into consideration such things as changing productivity levels and conditions as manhour requirements for different work areas are planned, rather than blindly allocated through traditional staffing modes.

Jan 1, 1995

By Robert Williams

A description is given of a double heat treatment of 60-40 brass. Photomicrographs are included to show the changes that take place in the microstructure on reheating the water-quenched specimens. A wide variation in the mechanical properties may be obtained by the described heat-treatment method. ON SEVERAL occasions, when 60-40 brass is first obtained in the beta condition by quenching at about 825° C. and is then reheated, the writers have noticed that recrystallization will take place in the form of twin crystals at the grain boundaries of the original beta crystals. It was, therefore, thought that interesting results would be obtained if this twinning process was studied further, especially as to the temperature at which it first occurs. The material used in the investigation was a bar of extruded muntz metal, 1/2 in. in diameter, and of the following composition: Copper, 60.21 per cent.; zinc, 39.73 per cent.; lead, trace; iron, trace; tin, nil. Specimens I in. in length were sawed from this bar and a hole was drilled into the side of each specimen until it reached the center, and the tip of a platinum-platinum rhodium thermocouple was inserted. A small Hoskins' resistance-type electric furnace was used for heating the specimens. The specimens were first heated at 840°C. for 2 hr. and then quenched in cold water, in order to get the material entirely in the beta state. In every case, in the reheating process, the furnace was brought to the desired temperature before the specimen was introduced. The time occupied in preheating was from 20 to 30 min. By sawing back 1/4 in. on each side of the hole, two parts were obtained from each specimen

Jan 3, 1924

By William Campbell

FiRst I must express my deep appreciation for the honor of being privileged to give the Howe Memorial Lecture this year and at the same time my feeling of inadequacy to do justice to the subject. The first Howe lecturer was most fittingly, Professor Sauveur, his contemporary and friend, and the subject was beta iron. Last year the second Howe lecture was delivered by Dr. Mathews, one of his most distinguished pupils, who spoke on austenite. This year, the Howe Professor of Metallurgy was chosen to deliver the third annual lecture, and the subject ought to be martensite. No one but Professor Sauveur could have brought to life what was considered by many to have been dead and buried, and he so persuasively and convincingly proved to us by his experiments the existence of something that the followers of that new cult "X-Ray and Crystal Structure " would have us believe is simply alpha iron. And Dr. Mathews from his wide practical experience was so easily able to convince us that austenite was not only the most wonderful of the iron-carbon series, but that it was the wonder alloy of the future. If I were to follow in the footsteps of my distinguished predecessors, I would talk to you about martensite. But when I had planned this lecture, I found that I was writing about Professor Howe and his work and his influence on the science of metals of today, and that martensite had become the secondary theme. And when finally I was obliged to choose a title, I remembered that it was in 1901 I came from Roberts-Austen with a letter of introduction to his very dear friend, Henry Marion Howe, at the Columbia School of Mines, to continue my work at the next bench to Dr. Mathews. Since then a quarter of a century has gone by, and during that time all branches of science seem to have been remade, so great has been our advancement in knowledge and discovery. And now that Metallography has finally established its place as an important branch of science, with its own textbooks and literature, I would like to review what seem to me to be the most important advances we have made in the last 25 years. To do this, I would start with Howe's "Iron, Steel and Other Alloys," and end with Jeffries and Archer's " Science of Metals." In the preface of the former, Professor Howe wrote: My warmest thanks are due to the friends who have aided me with their counsel and knowledge. In particular, let me thank most sincerely Prof. Margaret E. Maltby

Jan 1, 1926

By Brian Clifford

Thoresby Colliery is in the process of recovering an old roadway that was flooded following the closure of an adjacent mine. The aim is to re-use the roadway as a gate road for a longwall retreat panel and it is therefore important to establish the condition of the existing rockbolt support during the recovery operation. Two NDT methods, ultrasonics and RMT's newly developed RF (Radio Frequency) system were used in combination to interrogate the rockbolts to determine their condition. This paper describes the condition of the rockbolt supports, the NDT methods used and the problems that had to be overcome to successfully apply the two methods.

Jan 1, 2002

By Winston Gale

This paper is presents a summary of recent investigations into fracture and caving about longwall panels. The results of these investigations indicate that rock failure initiates well ahead of the longwall face. Rock fracture typically forms in response failure through the material and bedding planes. Tensile fractures also form in massive units. These fracture patterns typically create a fracture network which determines the caving characteristics encountered at the faceline. The action of longwall face supports under such conditions is to maintain confinement to the fractured ground and develop a consistent caving line, The confinement developed above the canopy under these conditions can be variable on a shear by shear basis and the operational face support procedures play an important role in stability about the face area.

Jan 1, 2004

By Luis Orna

El trabajo que se ha desarrollado en Minera Yanacocha, conjuntamente con las áreas de Mantenimiento Mina y Operaciones Mina, es realizar una solución integral en línea y tiempo real de la programación de las actividades de mantenimiento preventivo y correctivo de los equipos pesados en el taller de mantenimiento. La idea con esta solución fue que los planeadores, programen los trabajos desde su inicio a finalización, de modo que se visualiza el avance en diferentes dispositivos (monitores, dispositivos móviles, etc). Los técnicos del taller de mantenimiento, como valor agregado pueden monitorear sus actividades, cerrar las órdenes de trabajo si es necesario, todos estos trabajos son realizados con información mediante interfaz a ERP.

Sep 1, 2017

By J. D. Marchant

Solid-state electrotransport of impurities in cerium, lanthanum, and praseodymium, using a pulsed current, was investigated. The results were compared with those of using a steady current. Impurities that showed appreciable movement with the pulsed current, but not with the steady current, were as follows: Molybdenum and oxygen in cerium, aluminum, iron, and molybdenum in lanthanum. The use of a pulsed current enhances the practical application of solid-state electrotransport to remove a wider variety of impurities from the host metals.

Jan 1, 1971

By A. W. Fahrenwald

PRACTICALLY all fine grinding is done in a ball mill or some modification of a ball mill. Millions of tons of material are ground each year. The cost varies from, say, a minimum of 10 c. to a maximum of 35 c. per ton. It is thus obvious that even small improvements, which may result in increased grinding efficiency, would be welcomed by mill operators. A review of literature shows that various phases of the subject have been studied independently by many investigators. Also, it is now a subject of investigation at various laboratories in the United States and in foreign countries. Notwithstanding this extensive investigation, ball milling still remains a subject of some speculation. This paper presents the results of an experimental study of some of the factors entering into ball mill grinding.

Jan 1, 1931