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By A. Y. Senchenko, Y. V. Kulikov

"In recent decades HPGR technology has proven itself in comminution circuits of mining plants. High technical and economic performance, lower specific energy consumption and reliability of HPGR equipment makes it an efficient alternative to conventional circuits using stage crushing and rod/ball milling, as well as to AG/SAG circuits. However, despite all the advantages of this technology the correct selection of key and auxiliary equipment is very important since errors at testing and design stages may lead to discrediting of the whole concept of HPGR application. There is a great variety of possible circuit configurations using HPGR, e.g. with circulation of edge product, with crushing of the whole discharge and circulation of screen oversize, successive two-stage crushing, etc. Each type of minerals will require its own optimal crushing circuit. In this context the testing methodology for selection of an optimal configuration becomes of prime importance. It is common knowledge that the best simulation of material crushing and softening within a HPGR can be obtained only in the course of a large-scale pilot test. The main approaches applied to this kind of testworks are described in this article. Special aspects of HPGR technology design and industrial operation are revealed as well. Some operational issues of HPGR equipment and of circuit as a whole were detected. They are related to regions specifics, plants location, and other factors. Process solutions proposed to deal with these issues are also indicated in the article. INTRODUCTIONDesign and construction of the processing plants involving High Pressure Grinding Rolls (HPGR) technology becomes more and more common in mining as this technology has specific technical and economic advantages against the circuits with autogenous/semiautogenous mills (AG/SAG) and other circuits. The main advantage of the technology is low energy consumption and low operation costs respectively. The presence of microcracks and increased content of fine size fractions in the crushed product contribute to reduction of energy required for further ball grinding. Besides, HPGR technology applies a special wear resistant liner that enables significant reduction of operation costs of grinding media and liner comparing with AG/SAG circuits."

Jan 1, 2016

By Andrew McNamara, Stuart Norman, Matthew Dearing, Michael Pelken, Asha Panchal

The deep foundations industry has largely remained unchanged since in the advent of CFA piling in the 1960s. Piles have consequently been designed and constructed following the traditional codes and standards without much regard for optimising in-life efficiency or end-of-life reuse. After existing developments have been demolished there is little motivation to reuse existing piled foundations as their load bearing capacity and structural integrity cannot be verified. Therefore piling contractors are increasingly spending more resources on coring through existing piles, only to be replaced with larger diameter or deeper piles. The hollow element of the HIPER® Pile provides access to the entire length of the pile to permit inspections and a shaft in which the pile can be extended if needed. This paper presents and compares the embodied carbon savings, both during construction and through foundation reuse, from a HIPER® Pile scheme compared with the traditional solid pile scheme. A discussion on the benefits of this technology and its implications on warranties and approvals is also presented to motivate the foundations industry to embrace whole lifecycle assessments and support the journey to net-zero carbon.

May 1, 2022

By James E. McNulty

The planning and development of new coal mines is requiring the increased use of geologic, geologic engineering and hydrogeologic investigations. This is caused in part by the fact that new mines must deal with less favorable conditions than existing mines as well as higher costs of development and in part by the dictates of regulatory authority. High costs of new mines require greater reliability of geologic assessment using best available geotechnical and geophysical methods and technology. Although the increased cost of additional subsurface data is significant, the more important factor may be the impact on project lead time.

Jan 1, 1981

By James Paone

The Bureau of Mines made drillability studies with impregnated diamond bits in the laboratory on 7 rock types and in the field on 21 different rock types. Results indicate that drill parameters of rotational speed, thrust, and torque must produce sufficient applied forces to induce stress levels that cause continuous failure in rock to achieve efficient penetration rates. Higher rotational speeds appear to be more effective in drilling relatively harder rocks, although the increased speed causes more bit wear; increases in thrust result in higher drilling rates but not linearly; and up to a critical value a linear relation exists between torque and penetration rate for a specific rock type. Penetration rates with impregnated bits show a trend similar to that obtained with surface-set bits for rock under 25,000 psi compressive strength.

Jan 1, 1966

By M Ali, E Satriawan, M Napitupulu, A Munandar

The Deep Mill Level Zone (DMLZ) panel cave mine is one of three active caving mines at PT Freeport Indonesia’s Grasberg Underground Mining Complex. The DMLZ mine is located at a depth of approximately 1,500-1800 m below the surface, making it one of the world’s deepest panel cave mining operations. This depth results in both high in-situ and induced stress that acts on the hard and massive rock mass, triggering rockburst conditions. As a result of the bursting conditions, ground support and maintaining the support capacity are an essential part of operating the DMLZ mine in an efficient and safe manner.

Apr 26, 2022

By Stanley J. LeFond

Brazil is one of the most outstanding examples of economic development of our time. Its amazing growth record is substantiated by a GNP which has increased at an average rate of 92% for the period 1968-1970 and estimates for 1971 range from 11.7-12.5%. Hence, this growth, coupled with a more relaxed attitude of the Brazilian government towards foreign participation in business opportunities and the remittance of profits out of the country, has caused many exploration companies to reevaluate the potential of Brazil. Despite recent press notices and publicity, Brazil is still not a mining country in the tradition of Canada or Australia. It is still basically an agriculture and manufacturing country.

Jan 11, 1973

By AIME AIME

WEST TEXAS, New Mexico and Northern Mexico form one of the most interesting regions in America for geologists and mining men and are full of points of historical and human interest for others. Including as the region does, a representative portion of the high plateau of Mexico, the front range of the Rocky Mountains and the great down-dropping plains of Texas, there is variety as well as interest in the geological and mining problems there to be studied. Gold and silver mining were the pioneer industries and are yet of high rank in importance. Among the papers to be presented at the El Paso meeting of the Institute this month will be two dealing with silver mining and ore treatment at the Shafter mine in Texas, that most un- usual property which has for so many years been the largest mining enterprise in its region. West Texas is now better known for its petroleum and gas, and in another paper will be described the problems involved in uding natural gas for smelting at the well-known El Paso smelter of the American Smelting and Refining Co. In still other papers, presented at the session sponsored by the West Texas Geological Society and cooperating organizations, the general geology of the region, the potash and the sulfur deposits will be de- scribed. At El Paso the refineries of the great com- panics will be available for visits.

Jan 1, 1930

By H. Jiang, Y. Luo

The study develops an automated, high-efficiency drilling control system to reduce respirable dust and increase energy efficiency in underground coal mines. It uses specific energy to evaluate efficiency and proposes a comprehensive drilling control algorithm based on laboratory tests. The algorithm optimizes drilling parameters to maintain high efficiency, reduce dust generation, and improve safety.

Feb 12, 2022

By M. R. Hudec, M. A. Nikolinakou, P. B. Flemings

"We model the shale response to the large deformations associated with salt bodies, and we identify the implications of the stress changes for hydrocarbon exploration. We employ both the static and evolutionary approach, and show that while the static one can model actual geologic geometries, only the evolutionary approach can provide a detailed description of the stress history of shales, which is essential for predicting stress, porosity, and pore pressure and, more generally, for understanding Earth processes related to salt-hydrocarbon systems.INTRODUCTIONDuring the last two decades, understanding the stress, material behavior, and pore pressure in shales around salt bodies has become increasingly important. The energy industry routinely drills near salt (Beltrão, Sombra, Lage, Fagundes Netto, & Henriques, 2009; Meyer, Zarra, Rains, Meltz, & Hall, 2005; Seymour, Rae, Peden, & Ormston, 1993), because a significant number of hydrocarbon reservoirs around the world are found in layers dipping away from salt diapirs.Salt is a viscous material that cannot sustain deviatoric stresses. Under differential loading it flows, changes shape, and eventually relaxes to an isostatic stress state (Urai & Spiers, 2007). Therefore, emplacement of a salt body and its viscous relaxation process may cause significant deformation of the surrounding sediments, perturb their state of stress and create local overpressures (Dusseault, Maury, Sanfilippo, & Santarelli, 2004; Seymour et al., 1993). As a result, drilling near salt is particularly challenging, and problems leading to additional expense or even abandonment are common (Bradley, 1978; Dusseault et al., 2004; Meyer et al., 2005; Seymour et al., 1993; Willson et al., 2003).Historically, salt and the evolution of its cross section to the present day geometry have been studied using kinematic restorations (Rowan & Ratliff, 2012). This approach aims to explain the present geologic section through a sequence of plausible past sections; however, it does not model the constitutive response of the wall rocks, hence it cannot provide any prediction on their state of stress. Similarly, largestrain numerical studies (Albertz & Beaumont, 2010; Chemia, Schmeling, & Koyi, 2009; Goteti, Ings, & Beaumont, 2012; Gradmann, Beaumont, & Albertz, 2009) have focused on the rheological evolution of salt systems without modeling the geomechanical response of the sediments."

Jan 1, 2015

By Pinakin C. Chaubal

Today?s steel industry is in a vibrant and resurgent mode. This transformation has been in the making for some time now. Over the last few decades, the industry was steadily transforming itself into becoming a high tech industry. New technology was adopted, efficiencies were enhanced, lean manufacturing concepts were brought in and a strong customer focus was developed. Today?s mills employ sophisticated instrumentation, computerized monitoring, on-line smart systems etc. driving processes that are producing at rates of many tons/minute. All this is not possible without judiciously using the latest available technologies in various fields and developing a more sophisticated work force. Prof. Sohn has been a pioneer in driving the concept of process engineering in process metallurgy. In this paper the focus is on some aspects of process engineering ? primarily process modeling - as applied to iron and steelmaking processes. Examples are shown to demonstrate how problems have been addressed. Some thoughts on future directions are presented.

Jan 1, 2006

By Pinakin C. Chaubal

Today?s steel industry is in a vibrant and resurgent mode. This transformation has been in the making for some time now. Over the last few decades, the industry was steadily transforming itself into becoming a high tech industry. New technology was adopted, efficiencies were enhanced, lean manufacturing concepts were brought in and a strong customer focus was developed. Today?s mills employ sophisticated instrumentation, computerized monitoring, on-line smart systems etc. driving processes that are producing at rates of many tons/minute. All this is not possible without judiciously using the latest available technologies in various fields and developing a more sophisticated work force. Prof. Sohn has been a pioneer in driving the concept of process engineering in process metallurgy. In this paper the focus is on some aspects of process engineering ? primarily process modeling - as applied to iron and steelmaking processes. Examples are shown to demonstrate how problems have been addressed. Some thoughts on future directions are presented.

Jan 1, 2006

By C Staak, H Mischo, A Fichtner, F Reuter

In mining and remote areas of resource industry, there has been a development towards lacking emergency medical first aid response, that creates a potential disadvantage for patients after work accidents and other medical emergencies compared to standard population. This raises the question how a professional emergency medical coverage can be provided underground, taking into account lacking medical professionals in small resource companies combined with long rescue times. Aiming on the closure of this gap, a team of the mine rescue brigade from the Research and Training Mine Reiche Zeche (Forschungs-und Lehrbergwerk (FLB) Reiche Zeche) of the TUBAF Technische Universität Bergakademie Freiberg in Freiberg/Germany and its cooperating emergency departments of the Freiberg District Hospital and the Zeisigwaldkliniken Bethanien Chemnitz developed a totally new rescue concept using elements from tactical medicine and advanced emergency medicine combined with a specifically designed compact equipment and a highly standardised teaching curriculum. A fully new standardised and condensed tactical medical approach was developed including specifically adjusted equipment, and was taught in a didactically optimised way within 16 lessons in two days. Objective Structured Practical Examinations (OSPE) using manikins and simulated patients were conducted and compared to the identical exam of the reference group, which consisted of advanced paramedics. The standardised tactical medical scheme includes vital functions and body checks, advanced life support, nasal and intraosseous drug application, supraglottic airway management, artificial ventilation, thoracocentesis, bleeding control including tourniquet, fracture repositioning and splinting, transport bedding and thermal preservation. The developed Tactical Medical Mining Rescue (TMR) concept was subsequently included in the German guidelines for mine rescue services in 2022 and is already implemented in many companies in Germany and several international projects.

Sep 1, 2024

By C. K. Blankenship

The competitive forces now driving the electric utility industry and the constraints of regulation at all levels are changing the way we will all do business now and into the next century. Utilities are using every technological tool at their disposal to find optimum solutions to challenges in every aspect of operations. In fuel planning and procurement, these tools include models that predict which dispatch line-up will comply with environmental regulations at minimum cost. This paper presents how those tools are being used for Duquesne Light Company.

Jan 1, 1995

The Institute has set important objectives for 1988 to make the Institute still more purposeful. Precious metals The Second International Symposium on Mining, Extraction, and Processing of Precious Metals will be held in Las Vegas, Nevada, USA, during the 118th TMSAIME Annual Meeting in March 1989. The First International Symposium on Precious Metals.

Jan 1, 1987

By Henry M. Harris

Low-carbon shales from 65 deposits and 11 sources of coal-mine waste in western Oregon and Washington were tested in a rotary kiln for their suitability as raw material for expanded aggregate. Shales from 41 sources bloated enough to produce crushed, expanded aggregates, weighing less than 65 pounds per cubic foot in the preliminary tests. The samples were judged on the basis of processing qualities, physical properties, and size and uniformity of the source. Nine low-carbon shale deposits and three coal-mine waste sources were selected for more extensive bloating tests and for examination of the expanded aggregates in concrete shapes. Composite samples from these 12 sources and from 2 commercial operations, when processed for testing in concrete shapes, had bulk densities ranging from 37.S to 72.9 pounds per cubic foot. Damp-cured concrete shapes made with these aggregates had bulk densities ranging from S6 to 119 pounds per cubic foot, and all but three of the lightweight concretes had crushing strengths ranging from 3,270 to 6,810 p.s.i. Properties of the lightweight concretes were compared with those of concrete shapes made with commercial aggregates, and with sand and gravel.

Jan 1, 1962

By M. Onifade, O. S. Otuogbai, A. F. Mulaba-Bafubiandi, O. D. Eniowo, H. Grobler

Artisanal and small-scale miners in Nigeria struggle to attract formal financing to upgrade their operations to a more sustainable form of small-scale mining operation. Literature shows that for an investment to attract formal sources of financing; the business must be considered creditworthy by potential lenders. This means that the credit risks associated with the investment must be bearable for the potential lender. This study looks at how artisanal and small-scale miners can attract formal funding, which will help them take the leap from artisanal state to a form of sustainable small-scale mining operation. This study evaluates the creditworthiness of artisanal and small-scale mining operators using key credit risk parameters identified in the literature and through primary investigation. A quantitative study is conducted on a sample of 100 artisanal and small-scale miner establishments in Nigeria to evaluate the effect of these identified credit risk parameters on creditworthiness. It is shown in this study that being a member of a mining cooperative society, which is a form of social collateral, best improves the chances of access to formal financing for miners within the sample group. This underpins the role of social collateral, in both the formal and informal economy, and its influence in improving the creditworthiness of a typical artisanal and small-scale miner.

Jul 23, 2025

By H. Schunnesson, H. Fredriksson, D. Johansson, E. Söderström, S. Manzoor, A. Gustafson, M. Danielsson

Fragmentation analysis is an essential part of the optimization process in any mining operation. The costs of loading, hauling, and crushing the rock are strongly influenced by the size distribution of the blasted rock. Several direct and indirect methods are used to analyse or predict fragmentation, but none is entirely applicable to fragmentation assessment in sublevel caving mines, mainly because of the limitations imposed by the underground environment and the lack of all the required data to adequately describe the rock mass. Over the past few years, measurement while drilling (MWD) data has emerged as a potential tool to provide more information about the in-situ rock mass. This research investigated if MWD can be used to predict rock fragmentation in sublevel caving. The MWD data obtained from a sublevel caving mine in northern Sweden were used to find the relationship between rock fragmentation and the nature of the rock mass. The loading operation of the mine was filmed for more than 12 months to capture images of loaded load-haul-dump (LHD) buckets. The blasted material in those buckets was classified into four categories based on the median particle size (X50). The results showed a stronger correlation for fine and medium fragmented material with rock type (MWD data) than coarser material. The paper presents a model for prediction of fragmentation, which concludes that it is possible to use MWD data for fragmentation prediction.

Mar 2, 2022

By R. W. Raymond

THIS meeting was held in the new home of the Institute, the United Engineering Society Building, 29 West 39th Street, New York City, directly following the Dedication ceremonies. The first session was held in the large Auditorium, Thursday, April 18. The meeting was called to order by Mr. John Hays Hammond, President of the Council, who said Before taking up the reading and discussion of papers, I will call upon Dr. Rossiter W. Raymond, the oldest living past-President of the Institute, who has been in harness almost continuously for thirty-six years, and who has contributed more than any one else to bring this society to its present great success and to establish the reputation of the American mining engineer the world over, for a few words supplementary to those which were uttered to engineers generally, during the sessions of yesterday and the day before. ADDRESS BY R. W. RAYMOND. The generally accepted Darwinian doctrine of the survival of the fittest is sometimes illustrated by persons who are supposed to be the fittest because they have simply survived. I fear that I come under that category. Almost all of my contemporaries in the early history of this Institute have passed away. Only one or two of the original founders remain, and I may fairly say that scarcely any remain who were active at that : time in shaping the organization and the future career of the Institute. In May, 1871, I was thirty-one years old. Next week I shall be sixty-seven years old. All the intervening years have been devoted to the service of this Institute almost continuously, either as President or Vice-President or Secretary. You may easily imagine, therefore, with what pleasure I greet you on this occasion. I am not here to extend to you the welcome of the City - of

May 1, 1907

By T. G. Joseph, G. W. Hansen

"This paper considers the duty cycle of an electric cable shovel and correlations with measured passive seismic responses of the underfoot oil sands material in-pit. It has been observed that the cyclic activity during operation of any shovel in the oil sands environment causes the material to deteriorate and provide a less than ideal footing for this large item of equipment, whose dead weight approaches 1500 tons with a footprint of merely 75 sq. yd. Consequences are manifested in the form of carbody and side frame cracks, and associated downtime, maintenance activity, cost, and subsequent loss of availability.The objective of these considerations, as part of the Oil sands-Equipment Interaction Program (OsEIP), currently a joint venture between Syncrude Canada Ltd., James Progithin International (JPi) Ltd., Caterpillar Inc., P&H MinePro and the University of Alberta, is to identify and provide feedback to the manufacturer and end user of adverse shovel-ground conditions. This would enable the manufacturer to incorporate greater knowledge into the design process and the end user to direct operations in an enhanced proactive maintenance stance."

Jan 1, 2002

Engineering Experiment Station, Kansas State College, Manhattan, Kansas. For publications or a list of publications, address the above Of the 29 Bulletins issued by the Engineering Experiment Station, a few on cement and road-building materials may well be listed here: Bulletin 12, Road materials of Kansas; 15, Tests of Kansas road materials, 17, Some strength characteristics of portland cement; 25, Volume change of concrete, 26, A study of fourteen brands of standard portland cement and four early-strength concretes, 28, The durability of concrete, 29, The effect of aggregate and other variables on the elastic properties of concrete

Jan 1, 1933