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By J. Girard-Dwyer, T. Camm

Direct costs such as medical, legal, administrative, and worker’s compensation costs, property damage, lost earnings, and lost benefits are typically used to compute the economic impacts of occupational injuries. However, there are also a number of less obvious, indirect costs that substantially contribute to the overall loss costs. In fact, for every $1 of direct costs an estimated $3 to $5 of indirect costs are also incurred. This paper presents a systems approach that incorporates engineering, economics, psychology, and sociology in order to evaluate the total value of investments in safety. By studying the interrelated system comprised of the injured worker, their family and coworkers, as well as the organizational structure that was the setting for the incident, a methodology can be developed that will more accurately capture the true costs of mine injuries.

Jan 1, 2004

By S. J. Porter, M. T. McRae

The Melbourne City Link project includes two three-lane highway tunnels, 1.6 and 3.4km long, respectively, which are both approximately 16 meters wide and 9 meters high. The tunnels will be excavated through interbedded, moderately to highly jointed siltstones and sandstones of the Silurian Age Melbourne Mudstone formation over the major parts of their lengths. The strength of the intact rock varies from less than 5 MPa to greater than 70 MPa. Based on the available information regarding the performance of large span tunnels in weak rock, it was considered that the commonly applied empirical design guidelines for tunnel support, based on rock mass classification systems, should be augmented by more explicit design methods. The support design was, therefore, validated by analytical procedures, including numerical analyses, which are described in this paper.

Jan 1, 1997

By Z. H. Xie, D. S. He, W. M. Xie

China has rich phosphate rock resources, but with their continuous depletion, the rich ore resources have become increasingly scarce, which makes the exploration of collophane more important. Medium- and low-grade phosphate rock cannot be utilized until their impurities have been removed through mineral processing. However, due to the similar physical and chemical properties of dolomite and phosphorus minerals, the separation of dolomite from phosphate

By Adrian Molinari

A radioisotope probe (Minexan 202) capable of simultaneously analyzing a mineral slurry for five elements and pulp density has been developed by Outokumpu Oy, Finland. The probe is designed to operate immersed directly in a process stream, or it can be equipped with a flow cell through which passes a continuous sample of the main stream. A minicomputer (PDPII) is used to control the probes and calculate the assay data. This paper describes the probe as applied to slurry analysis and compares it to the conventional x-ray on-stream analyzer (Courier 300).

Jan 1, 1977

As 1979 drew to a close, it was obvious that China would have another good year with output of most industrial products at 3-9% above levels attained in 1978. Most increases were registered on the basis of maximum utilization of existing capacities and nationalization of procedures and methods. There were also distinct improvements in the quality and variety of products. Coal output probably surpassed the 650-Mt level in 1979. Steel output was expected to reach the 35-Mt level, an increase of nearly 10% over 1978. Based on the vast amount of housing and road and project construction, cement production more than likely surpassed 70 Mt. The nonferrous base metal industries improved somewhat in 1978, but actual output levels in recent years may have been a little higher than previously estimated by the outside world. Stagnate world demand slowed growth in the "export metals" sector. Minerals like magnesite and talc were produced at tonnages much larger than previously thought, with gold also falling into this category. Sulfur and pyrite production are still short, although a big pyrite mine was being brought into production. Barite out-put was reportedly up and fluorspar output held its own. Westerners generally concede that difficulties in transportation and power supply are holding back mineral production. Throughout 1979, basic construction continued on the majority of projects started by the Chinese and those few foreign projects contracted before the adjustment of industrial priorities. Foreign Ventures Perspective The foreign connection looms large in China's plan for modernization. In effect, it is an extension of what China wants to do in terms of "walking on two legs"-that is, develop what can be done locally to the fullest extent, then rely on international technology to move into the bigger and more complicated projects. Foreign projects are designed to complement domestic projects rather than replace them. Many foreign projects were started or continued by the Chinese in 1979. Building the necessary infrastructure for the projects is usually a Chinese endeavor and requires Chinese technicians and money. In areas with a strong economic base, this activity proceeds without foreign aid. In other areas, added funds are requested. Foreign funds can come in many forms-equipment technology, low interest loans, equity capital, advance-of-funds on the basis of future delivery in kind, and joint venture money. The Chinese are exploring all these avenues, with the strategy of minimizing foreign exchange needs for individual projects. They feel very uncomfortable with high interest rates, even though interest can be treated as operating ex¬pense rather than capital expense. Then there's the question of rights. Will Chinese sovereignty be affected? Can foreigners own land, in addition

Jan 3, 1980

By Fred W. Brackebush

In underground stopes that require more than minimal support, backfill is almost universally used. The term cut and fill stopingis used in a broad sense in this section, which describes underground mining methods requiring support. Support in stopes can be classified as local or short-term and general or long-term. Local support for the back of a stope, for example, can be accomplished with rock bolts or timber stulls. General support for the walls of the stope is provided by backfill. Local support provides a safe working place for the stope miners. General support, provided by backfill, preserves the access way to the stope and prevents large scale dilution of ore. Supported methods are a set of cut and fill stoping methods using backfill for general support and various local support methods. his section is subdivided into three chapters: 19.1 Cut and Fill Mining 19.2 Excavation Techniques 19.3 Backfilling Methods

Jan 1, 2008

By J. J. Zaluski

The Surface Mining control and Reclamation Act (public Law 95-87) (here-inafter the "Act" or "SMCRA") passed by congress in August of 1977 represents a comprehensive federal scheme for controlling surface coal mining and the surface effects of underground mining through permitting requirements, performance guidelines, and reclamation planning. While the provisions of the Act have been the subject of numerous legal challenges and court battles over the years, it is difficult to identify a more controversial program within the Act than the provisions for designating lands as unsuitable for surface coal mining operations. The lands unsuitable designation process provides for the acceptance and review of petitions submitted by citizens or organizations seeking to have specified land areas designated unsuitable for all or certain types of surface coal mining activities. In filing these petitions, the interested parties or petitioners are required to make allegations about potential adverse impacts on people or the environment and submit evidence supporting their allegations.

Jan 1, 1992

By Jay P. Chapman

The basic control requirement for multi-pump, long distance slurry pipelines are discussed and a particular example of an operating slurry pipeline using programmable controllers is presented.

Jan 1, 1983

By Frederic Chavan, Hans Jakob Windier, Shane Yanagisawa, Willy Ritz

The Zurichberg twin track tunnel is the main segment of the Swiss Federal Railway's new expressline. A heavy concrete lining with a circular cross-section was chosen to cope with the swelling tendency of the surrounding rock. The 4,356 m (14,300 ft) long, 11.52 m (38 ft) diameter tunnel was driven using a shielded Robbins TBM. A 1.20 m (4 ft) wide, 25 cm (10 in) thick precast lining was placed from within the shield tail as the excavation progressed. Tunnel excavation and initial lining operation were completed in 18 months, averaging 11.86 m/day (40 ft/day) in two nine hour shifts. After breaking through, the final 28 cm (11 in) thick concrete arch lining was cast in place.

Jan 1, 1989

By I. R. M. Chaston

Abstract. This paper puts forward the concept of 'radial' plant layout where all crushing, milling and treatment operations are preferably concentrated in one central area and these separate stages are connected by radiating conveyors to and from outside storage areas. This system is contrasted to the more customary system of 'linear' plant layout where the crushing, milling and often the treatment operations follow one after the other in separate buildings. The radial system simplifies and improves contral and supervision to a very considerable extent and can lead to a form of continuous plant operation with the separate sectors shutting down in succession for necessary maintenance while maintaining the overall plant operation. The paper is illustrated with example: from past and recent diamond treatment plant practice in South Africa which demonstrate the reduction in plant labour achieved by this system. Previous objection to this type of layout on the grounds that it inhibited plant expansion are shown to be unwarranted. Radial Layout for Increased Treatment Plant Productivity A great deal of time and trouble is spent by highly qualified and experience( metallurgists in developing the right treatment process for a given ore. This process is then often expressed in a treatment flowsheet of the type shown in Fig. 1 which shows a typical diamond plant. This flowsheet, when completed, is commonly handed over to the mechanical engineers who then design the layout of the equipment indicated on the flowsheet and produce the working drawings upon which the detailed construction of the treatment plant will be based. It is an unfortunate fact that the tedious and time-consuming juggling of equipment and inter-plant transportation is often left to hard-working draughtsmen who, however capable' in their field, lack practical experience in the day-to-day operation and maintenance of the treatment plants they design. As a result many plants have been produced which, while they satisfy the requirements of the flowsheet with minimum capital requirements, cost far more than should be necessary to op¬erate and maintain. It is often possible to change individual items of equipment which do not achieve the performance required of them, but it is usually extremely expensive to change the basic layout of the plant if this should be found to be unsatisfactory. It should therefore be recognised that great care and attention should be spent on consideration of the basic layout of any treatment plant and that the views of both designers and operators should be fully regarded before settling upon the inevitable compromise dictated by the varying requirements of process-engineering and economics. It is unfortunate that this important subject receives such scant regard in the standard ore dressing text books and hand-books, being usually dismissed in a few paragraphs.

Jan 1, 1977

By Dennis N. Poffenroth

One concern of the Mine Safety and Health Administration is the structural integrity of steel wire ropes used on mine personnel hoists and elevators. Failure of such ropes has resulted in loss of life and property. Although thorough and regular visual examinations are performed, hoist ropes may still fail from undetected internal wear, corrosion, and broken wires. To complement visual examinations, nondestructive rope inspection techniques have been developed to determine deterioration and removal criteria. The techniques use electromagnetic and permanent-magnet test instruments designed by a Canadian firm. This paper describes the operating principles, field and laboratory testing of these nondestructive testing instruments, and discusses the feasibility of using this type of testing as a supplement to visual examination and destructive tests.

Jan 1, 1983

By Ross K. Digby

The Victorian Tunnelling Centre (VTC) has evolved its purpose from purely training workers, to a tunnelling industry education city. The VTC has now focused its activities on the areas of technology; education and training; applied research; and career education. were identied as the hus around which activities would e conducted to create a tunnelling industry education city. The VTC provides ustralias tunnelling industry with an education facility that not only provides laour training, ut enales the industry to come together to meet, participate in product launches, undertake research, work with new technologies and promote tunnelling careers.

Jun 23, 2024

By M. Dayne Aldridge

A discussion of the definition of automation in mine ventilation applications is presented. The results of theoretical studies, experiments and practical experience from work in the United Kingdom, Belgium, Poland, the Soviet Union and the United States are summarized. Conclusions are drawn from these efforts and the prospects for the future development of automatic mine ventilation systems are explored.

Jan 1, 1978

By Peter Kreisman

This paper and four other papers on the MEQB Regional Copper-Nickel Study, presented today at the 1980 SME-AIME Fall Meeting are based on four years of extensive inter-disciplinary research and impact analysis supported largely by the Legislative Commission on Minnesota Resources. This study produced over 180 technical reports, the results of which are summarized in an Executive Summary available from the Minnesota State Planning Agency, St. Paul, Minnesota. Those wishing to examine the many scientific, engineering, environmental, social or economic issues addressed by the study are encouraged to obtain a copy of the executive summary. The executive summary includes a bibliography of all technical reports produced by the Regional Copper-Nickel Study and describes the five-volume, 26 chapter Regional Copper-Nickel Study Report.

Jan 1, 1980

By E. C. Winegartner

In producing and selling coal, the coal company is faced with many different parameters by which the quality of its product is evaluated. One type, which we choose to call the economic parameters, includes moisture, ash, sulfur, and Btu's. These are reasonably well understood by both the coal supplier and the customer, and the dollar values can be placed on them. This is the group of parameters of primary interest to most purchasing agents buying coal. A second group of parameters governs how the coal will behave in the boiler itself and is of primary concern to the engineers designing the boiler and to the men who must operate and maintain it. Since we have not yet learned to put dollar values on these parameters, they generally show up in coal contracts simply as cutoff points, the purchaser simply saying that he will not accept coal outside of certain limits.

Jan 1, 1975

By Qingqing Huang, Mohammad Rezaee

The Mineral & Metallurgical Processing Division (MPD) of the Society for Mining, Metallurgy & Exploration held the 12th MPD Student Poster Contest on March 2, 2022, during the MINEXCHANGE 2022 SME Annual Conference & Expo. The event showcased the work of 32 graduate and undergraduate students from U.S. and international institutions. The contest began in January when the students submitted one‐page abstracts for judging. In February, they prepared and presented posters that explained their research, and each student had five minutes to explain their research to a panel of judges during the conference. Recognizing the students’ efforts in working hard on their research topics and setting aside time to complete the necessary steps to enter the poster contest, the MPD provides monetary rewards to all participants. For graduate students, first place receives $1,000, second place $500, and third through seventh places $200 each, and for undergraduate students, first place receives $1,000 and second place $500. The main authors of nonplacing entries receive $125 each. Participation in the contest includes a free ticket to the MPD Luncheon, where the winners are announced.

Nov 22, 2022

By C. D. Buttgereit

A variety of mathematical techniques are available in the pertinent literature concerning the interpretation and reduction of aeromagnetic data. The quantitative methods applicable to this data en¬compass a wide spectrum including filtering, continuation, derivatives, reduction to the poles, spectral analysis, and "undraping" of flight line data. With the aid of the digital computer, the techniques listed, and others, can be computationally performed on a gridded data set. In addition, current sophisticated computer hardware permits the systems analyst greater latitude in the storage and retrieval of data and in the display of resultant naps on a digital x-y plotter than previously available. Although many interpretive techniques concerning magnetic data have been published and computer machinery has been on the market, little has been written incorporating both disciplines into a unified digital processing system. In the present paper, a general purpose system in given which in designed for routine use in the interpretation of aeromagnetic (and other potential field, etc.) maps.

Jan 1, 1970

By R. Hawker, P. Singh, K. V. Jessu, P. C. Pinazzi, A. J. S. (Sam) Spearing

Rock bolts are highly important underground to prevent falls of ground and thus, ensure safety. In situ, the ground reinforcement is subjected to a combination of loads, such as shear, tensile, and/or bending loads. Studies have been conducted to evaluate the effect of either shear, tensile, or bending loads on the ground support. However, only a few studies have been done to evaluate the effect of combined load on the rock bolt performance. In situ, the order of loads acting on the bar cannot be predicted, and more than one load can act on the bar at the same time. Thus, a hybrid failure criterion was developed that covered all combined loading conditions. Fifty-eight un-grouted laboratory rock bolt tests were conducted in total under two load conditions: applying shear displacement to the rock bolt and then tensile load to failure, and applying tensile displacement to the rock bolt and then shear load to failure. From the test results, the failure criterion was developed based on regression analysis. A nonlinear relationship was determined for the loading condition variations. The failure criterion presented in this paper can be used as a guide in the rock bolt capacity design under all loading conditions.

Sep 8, 2020

By M. Misra

Improved liberation and flotation of kerogen from eastern oil shale were accomplished with high-temperature grinding and a1 so with the addition of fuel oil during the grinding stage. Liberation measurements indicated that possible coalescence and aggregation phenomenon of kerogen particles during grinding may reflect this behavior. Additionally, ultrasonic treatment of the rougher concentrate prior to cleaning improved the quality of separation.

Jan 1, 1984

By A. M. El Shafey, Ahmed W. Hussein, Ibrahim M. Gaafar, Mona M. Fawzy, Mohamed Diab, Mohamed S. Abu El Ghar

The Quaternary stream sediments of the Diit area, southern Red Sea coast, Egypt, were mineralogically studied for their content of economic heavy minerals. The study area covered approximately 450 km2 and included three main parts: Wadi and Delta Diit, as well as Diit lens. The mineralogical investigation revealed that these sediments contain considerable amounts of placer ilmenite, magnetite, zircon, sphene, apatite, garnet, and rutile. Also present, in minor or trace amounts, are uranothorite, monazite, xenotime, fergusonite, khatyrkite, and gold. The magnetic fractionation tests, supplemented with the XRD and SEM mineral analyses, indicated the presence of Fe-oxide minerals as wuestite, hematite, and maghemite accompanied with magnetite as products for hand magnet separation. Ilmenite separation was carried out using a high intensity magnetic separator at a current of 1 A, while the paramagnetic minerals (e.g., garnet, pyroxene, amphibole, epidote, monazite, xenotime, and fergusonite) were separated as magnetic fraction at a current of 3 A. The non-magnetic minerals (e.g., zircon, apatite and rutile, uranophane, uranothorite, gold, and khatyrkite) were obtained at 3 A current. On a mineralogical and geochemical basis, the present work suggests that Diit stream sediments should be considered as a potential source for Ti, Fe, Zr, Zn, and Cu after the physical upgrading processes for concentrating the minerals carrying the aforementioned economic elements.

Jan 21, 2022