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By D. A. Mackie, J. E. Rider

"Good belt conveyor design is the most often neglected detail in the engineering of a plant. This results in downtime from spills or jams and premature failure of equipment components. Careful layout and component selection will result in better operation, a cleaner plant and therefore lower maintenance costs.IntroductionDespite the availability of many excellent sources of data on conveyor design, such as the Conveyor Equipment Manufacturers' Association (CEMA) Manual, ""Belt Convyors for Bulk Materials"" , there continues to be repetitive errors made in design. Why? Certainly, there is no substitute for experience, but largely, classical errors in belt conveyor design is rather elementary and so the temptation to have the work done by relatively inexperienced designers is great. What that does is develop "" experienced"" designers who become incompetent through no fault of their own. It is hoped that this paper will supplement available design data, help those who are "" put into"" a design situation to better cope with their predicament, and ease the lives of plant maintenance personnel."

Jan 1, 1990

By Sasa Djokic

In developed countries, the difference between demanded and produced quantities of non-ferrous and rare metals are compensated by secondary raw materials recycling and reprocessing of by-products from both ferrous and non-ferrous extractive metallurgy. Utilization of non-ferrous and rare metals from the metallic secondary raw materials is very significant, both for recovery of the metal value and contribution to the environment protection. Similar to all non-developed countries, the extractive metallurgy in Serbia was based on available natural resources and not so strict environment protection regulations, which was either insufficient or completely absent. Today, Serbia is at the beginning of development of efficient and economical technical and technological solutions in order to ?ecologize? technogenic systems by waste materials, secondary raw materials and degraded soils regeneration (by recycling and revitalization). Several metallurgical technogenic systems in Serbia, together with secondary raw materials classification according to their potentiality for metal extraction by using the existing technologies and expected economical and ecological effects of recycling, are discussed in this paper.

Jan 1, 2005

CHAIRMAN EMRICK: We have a very interesting program this morning, of a mechanical nature, and I am sure you will all be very much interested in it. At the conclusion of each paper there will be time given for discussion, and we will be glad to have all of you enter into the discussion. Before we start the program, I want to ask the men who have been appointed chairmen of committees to come and get these folios, which contain papers concerning their particular committees. The Nominations Committee, of which David Brown is chairman, has a folio here. It has been customary every year to have a photograph of those in attendance taken, and I presume it is the will of those in attendance this morning to have their pictures taken. We plan to do that about a quarter of twelve, approximately, this morning in the room instead of going outside as we have heretofore. Frank Miller has an interesting an¬nouncement to make. Frank, if you will just take about five minutes to tell your story.

Jan 1, 1934

By Marc C. Bétoumay

Workplace safety, health, climatic conditions and rising oil prices are aspects that are important to the mining industry. The need for cleaner energy for underground mine vehicles is requiring serious consideration. A number of alternate energy systems offer clean solutions to diesel emissions while maintaining the current liberty of vehicle movement. This watershed article provides a broad comparison of cleaner diesel and alternative energies for underground production vehicles. Most alternate energies and clean diesel have already been tested in underground production vehicles. There are no technology gaps that would prevent the development of commercial alternative energy power plants, but in the case of alternate energies, second and third generation versions will be required to fully test for safety and operation viability. Full regulatory development is also required and could be done in parallel to power plant testing. Vehicle operation and maintenance manpower would be the same for alternate energy application as for clean diesel. Capital cost for alternate energy power plants will remain higher until the medium term. Owing to significant ventilation savings possible with alternate technologies, operating costs would be reduced.

May 1, 2011

By J. Boulton

"Nuclear energy is an established and proven energy source. Today, CANDU-PHW nuclear-electric generating stations produce over one third of Ontario's total electrical supply: safely and economically. In many parts of Canada, where economic hydro resources do not exist or are fully developed, coal and nuclear energy are the only alternatives for future large-scale electrical generating capacity.Recent analyses have suggested that, in the f ace of increasing energy demands and decreasing reserves of hydrocarbon fuels, Canada must depend on electricity to provide an expanded fraction of its energy budget. Nuclear energy is likely to play an increasing role in the generation of electricity; there are also potential applications as a supplier of process heat in industry and in the in-situ recovery of bitumen fro m tar sands.The future supply of nuclear fuel, reactor safety and radioactive waste management are briefly discussed. In each case, the benefits to be gained from a controlled expansion in the use of nuclear energy outweigh any uncertainties which may exist."

Jan 1, 1981

By Bradford P. Simser

Increasingly sophisticated rock mechanic tools are becoming more and more available for today?s ground control specialist. However many problems are still beyond our ability to explicitly calculate or measure. There is often a gap between the ?art? and the ?science? of rock mechanics. This paper focuses more on the ?art?, giving relatively simple examples of underground observations and micro-seismic records to help explain ground control issues. Ground support techniques such as in cycle shotcrete with high pressure water scaling, mesh and bolting, pumpable resin bolts/cablebolting, and yielding bolts with load spreading straps are discussed. The use of primary/secondary type blasthole sequences in moderate to high stress situations is also discussed with several examples of the micro-seismic response to the stoping. Relatively erratic geology with high material strength contrasts is currently being mined with blasthole methods at Nickel Rim South. Although the mine is still in its? ?early? days, over 1 million tonnes has been extracted and some empirical experience is highlighted with potential longer term issues also being discussed.

Oct 1, 2010

By M. M. Tilman

The Bureau of Mines conducted research to evaluate superplastic behavior in commercial magnesium-base alloys AZ6IA, ZK60A, ZW3, AZ3IB, ZWI, and an experimental Mg-12 pct Al alloy. Strain-rate sensitivity indices (m-values), maximum elongations, and effects of superplastic elongation on tensile properties were determined on fine-grained sheet. Inert-gas-pressure hemisphere-forming tests were conducted on selected sheet stock of the five alloys. Formability trials on AZ31B alloy sheet were conducted on industrial equipment for comparison with commercial superplastic forming of Zn-AI alloy. Closed-die-forming tests were performed on extruded ZK60A rod. All alloys exhibited well over 100-pct elongation, indicating superplasticity, at temperatures and strain rates near the maximum m-values. Tensile properties were generally reduced following 100-pct superplastic elongation, but not to an extent that would preclude use of the commercial alloys in the superplastically deformed condition. The potential for industrial superplastic forming of AZ31B sheet was indicated by hemisphere forming in the laboratory and substantiated in industrial forming trials.

Jan 1, 1982

By J. C. White

A research study was conducted to devise a method for producing phosphoric acid directly from unbeneficiated Florida phosphate matrix. This research was performed as part of the Bureau of Mines, U.S. Department of the Interior, goals of improving minerals and metals recovery from domestic resources and of minimizing the environmental impact associated with mineral recovery operations. This report describes research in which unbeneficiated, dry, south-central Florida phosphate matrix was digested with sulfuric acid in a continuous-circuit, five-tank reactor to yield phosphoric acid and gypsum residue. Feed capacity of the reactor was 100 pounds (45 kg) of dry matrix per 24-hour day. When digestion was carried out at 185° F (85° C), acid filtration rates of up to 420 pounds of P20S per square foot per day were attained. Combined iron and aluminum impurities in the product filter acid were about 60 percent greater than values reported in commercially produced acid derived from concentrate. phosphate recovery was 87 to 90 percent of the phosphate contained in the as-mined matrix.

Jan 1, 1978

Burra was the largest metalliferous mine in Aus- tralia between 1845 and 1860 and employed as many as 1000 men and boys. The workforce was predominantly Cornish, Burra being the first con- centration of Cornish folk in Australia. The sur- face and underground mining operations were typically Cornish and virtually all positions of responsibility were held by Cornishmen. Beam pumping and winding engines were imported from Cornwall and housed in traditional Cornish engi- nehouses. Burra had the first significant number of beam engines in Australia: six were installed between 1849 and 1861. These engines, ranging in size from 20 inches to 80 inches in diameter, were used for pumping, hauling, and driving Cornish roll crush- ers and dressing machinery. Derelict enginehouses of the great beam engines are a striking reminder of former mining activity in Cornwall and South Australia. In South Aus- tralia about 35 enginehouses were erected between 1848 and 1887, of which eight still remain, three of them at Burra (Figure 1). These remain as a tangible link with the Industrial Revolution.

Jan 1, 1987

A well known rock mass classification system has been altered slightly to address the issues found under remnant mining conditions. By detail study of the expected fracture patterns and local geology, the rock mass is classified to indicate the condition of the hanging wall prior to mining. The risk level of each mining step is evaluated by calculating input parameters for computer simulations from the actual rock mass condition. Seismic activity is catered for by the understanding that large event rates and large magnitude events reduce the quality of the local rock mass and that the rock mass stiffness should be adapted accordingly. A case study is presented to test parts of the protocol. Un système connu de classification des masses rocheuses a été légèrement modifié pour faire face aux questions posées par les conditions d’extraction de débris. Une étude détaillée des diagrammes de fragmentation et de la géologie locale permet de classer la masse rocheuse pour indiquer la condition du toit avant l’extraction. Le niveau de risque de chaque étape minière est évalué en calculant les paramètres d’entrée pour simulation par ordinateur à partir de la condition réelle de la masse rocheuse. L’activité sismique est prise en compte avec la réalisation que les taux de larges évènements et les évènements de large magnitude réduisent la qualité de la masse rocheuse locale et que la raideur de la masse rocheuse doit donc être adaptée. Une étude de cas est présentée pour tester des sections du protocole. Ein sehr bekanntes Gesteinsmassenklassifikationssystem wurde abgeändert um die Probleme zu behandeln die unter Restabbaukonditionen angetroffen werden. Durch detaillierstes Studium der der zu erwartenden Bruchmuster und der lokalen geologischen Verhältnisse wird die Gesteinsmasse in Hinblick auf die Konditionen der Flözoberseite klassifiziert. Das Risikoniveau für jeden Abbauschritt wird durch die Eingabeparameter aktuellen Gesteinsmassenkondition für die Computersimulation evaluiert. Für die Seismische Aktivitäten wird Sorge getragen durch das Verständnis, daß große Ereignisraten und Ereignisse hoher Größenklassen die Qualität der lokalen Gesteinsmasse reduzieren und daß die Gesteinsmassensteifheit entsprechend adaptiert werden sollte. Eine Fallstudie um Teile des Protokolls zu testen wird präsentiert.

Jan 1, 2003

By K. Fleck

Energy West Mining Co. (EWMC) has implemented a geologic program for improving stability and support requirements along deep two-entry longwall gateroads at its Deer Creek Mine operations located near Huntington, UT. Together with geotechnical monitoring and concurrent review of mine seismicity in cooperation with MTI staff, it has become possible to improve longwall layout designs for two seam extraction of the Hiawatha and Blind Canyon seams. The geologic program consists of surface and in-mine exploration drilling, surface and in-mine geologic mapping, rock mechanics testing and detailed measurements of changes in depositional and structural conditions during development of every longwall gateroad. The geotechnical program consists of underground measurements at seven locations in two neighboring mining districts located in the Hiawatha and Blind Canyon coal seams under moderate to deep cover. Within the last five years, additional measurements, including data on seismicity and face conditions, have been incorporated into the data collection program for verifying the in situ coal strength and load transfer mechanisms for improving two-seam designs and support systems.

Jan 1, 2012

By Larry G. Stolarczyk

This report deals with information regarding a new Medium Frequency (MF) Wireless Communication System for underground mines. This new telecommunication system works on low loss electromagnetic wave propagation modes which allow it to provide quality radio communications almost anywhere in a mine. Tests show the MF system can provide improved safety and managerial control, increased productivity, better organizational team-work and reduced maintenance cost; furthermore, MF's unique design allows for easy installation at a minimum cost. This paper covers the following: 1) MF design plan, 2) Overview of mine radio communications systems, 3) Preparations needed for designing an MF system, 4) MF equipment, 5) MF installation, 6) MF design considerations, 7) MF design specifica¬tions, and 8) Recommendations dealing with MF system. Experiments in four mines are illustrated to demonstrate the success and via¬bility of the MF system. The mines range from small (500 tons/day) to large (67,000 tons/day) capacity and represent several different mining methods. The MF Wireless Communication System represents an advancement in mining communication and the groundwork for other advanced mine systems.

Jan 9, 1984

By J. W. Furlan

Due to the time consuming nature of froth testing in a laboratory environment, it is required, due to practical limitations, to develop a method of applying a single set of performance test data (Visintainer & Whitlock, 2012) obtained for a single froth pump at a given speed, to a range of froth pump speeds and sizes, % air contents, and liquid viscosities. Head, efficiency, and flow all vary as functions of both liquid viscosity and air content. As such, it is necessary to develop a technique which can be used to interpolate from existing test data in order to predict froth pump performance for pumps of various sizes running at variable speeds. Details of the technique developed in order to achieve this goal as well as the insights gained from analysis of the resulting regressions are discussed. Additionally, comparisons are made between the performance predictions of this test-derived method and those of the Hydraulic Institute Standard for the effects of liquid viscosity on centrifugal pump performance (ANSI/HI 9.6.7-2010).

Feb 27, 2013

By Andre L. De Vegt, Cees J. N. Buisman

"For the past eight years Paques has been engaged in the development and installation of treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. Metal and sulfate can be removed from mine waters using two biological steps:1. Sulfate reducing bacteria convert sulfate to hydrogen sulfide (H2S). The H2S reacts with the dissolved metals to form insoluble metal sulfide precipitates.2. Sulfide oxidizing bacteria convert excess H2S to elemental sulfur.Paques has designed and installed a groundwater treatment system for the Budelco zinc refinery in the Netherlands to remove metals and sulfate as described above. The system has been operating since May 1992 treating a flow of 5000 m3/d. A test program, utilizing a large scale pilot plant, will commence in November 1995 at a copper mine in the U.S.A. to remediate groundwater contaminated with sulfate and heavy metals. Biological reactor performance and selective metal recovery will be studied. Sulfur dioxide (S02) can be removed from fluegas using a combination of scrubber technology and the two biological steps. The end product is elemental sulfur. A commercial size biological desulfurization plant has been in operation since July 1994 treating 50,000 Nm3/h of fluegas. Sulfide can be removed from mining waters or anaerobic wetlands using a THIOPAQ® Sulfide Oxidizing reactor.lntroductionSulfur can be present in various water and gaseous streams in a mining operation. In many cases the sulfur compounds have to be removed because of toxicity, corrosive properties and contribution to acid rain. Mine waters can contain dissolved heavy metals. An efficient way to remove dissolved metals removal is the precipitation as metal sulfides. Paques has developed and installed treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. These treatment systems biologically convert sulfate to hydrogen sulfide (H2S) which can be used in heavy metal precipitation. Excess H2S is biologically converted to elemental sulfur. This paper provides an overview of these newly developed biotechnological treatment systems."

Jan 1, 1997

By D. J. McLaws

"Recent innovations in metal smelting technology utilize continuous oxygen-enriched smelting and converting processes which are capable of producing off-gases containing up to 60% SO2 or more. Other SO2 recovery processes, involving solvent absorption and steam or vacuum regeneration, can produce off-gases with SO2 concentrations nearing 100%.Processing of these high-concentration SO2 off-gases in conventional sulfuric acid plants can cause excessively high catalyst bed temperatures and poor SO2 conversion. In order to avoid these problems, a conventional acid plant design must dilute these high SO2 process gasses with dilution air in order to provide the required oxygen to effectively convert the SO2 and provide a heat sink (via the inert N2) such that the exothermic reaction, SO2 + ½ O2 ???SO3, does not exceed the temperature limit of the catalyst or the converter vessel.MECS, Inc. (MECS) has proven that a high SO2 feed gas design can be a viable option which can increase energy recovery, reduce energy consumption and potentially reduce capital costs."

Jan 1, 2014

By Raymond L. Lowrie

Deregulation, as authorized by the Energy Policy Act of 1992 (PL102-486) allows free-market competition in the electric-utility industry. As the act unfolds, though, uncertainties abound about the type, degree and direction of impacts throughout the affected economy — from fuel suppliers to electricity generators and from power distributors to energy consumers. Instead of having a familiar base of captive customers and electricity prices fixed by negotiation with state public utility commissions, utility companies are preparing for open, free-market competition. They are looking at all areas, including fuel supply, to cut costs to remain competitive. Humorous anecdotes are told about utility companies shunning insiders for senior executive positions. Instead, they are opting for people from the telephone or other industries with deregulation experience. And there are light-hearted stories about a trend away from traditional electric-company names, such as the name of a city or state followed by Edison or Power and Light, to space-age names, such as Ameren, Entergy, Illinova or Unicom. No one wants to be left behind or be perceived to be left behind.

Jan 1, 1996

By A. R. Naderian

Laboratory strength and deformation testing of freshly blasted sandstone and claystone overburden from Jeebropilly colliery in Queensland and in-situ plate-bearing tests on four backfills of different ages showed that the bearing capacity of backfill is a function mainly of compaction, not of age. The modulus or stiffness of the backfill is significantly increased by previous loading, in some cases up to threefold. Backfill material experiences some compaction through the passage of mining vehicles, likely to provide a bearing capacity that will support normal construction activities; the limited testing performed suggested that completed backfills are capable of supporting loads of up to 200 kN/m2 while sustaining displacements acceptable for a wide range of residential and industrial uses, but may be susceptible to collapse settlements due to saturation in the long term

Jun 19, 1905

The objective in control blasting is to reduce overbreak to control the final pit wall slope, shaft, drift, ditch, bench, etc. to the final planned excavation limit.

Jan 1, 1991

By Stanley Lefond

The health of the industrial minerals industry appears to be improving year by year. In fact, preliminary information suggests that only three commodities (asbestos, bromine, and sulfur-other) failed to show a production gain in 1984 over 1983. In 1983, 10 commodities failed to post gains and six remained constant. The total value of industrial mineral production in 1984 was $16.7 billion, up $1.4 billion from 1983. Cement, clays, gypsum, and crushed stone production increased. Since these are used in housing and construction, this suggests these industries are moving out of their recent doldrums. Barite and clay production also improved in 1984. Local US barite production, however, still has a long way to go to attain the 1981 high of 2.6 Mt (2.9 million st). Barite imports remain high. But they are not as high as the 1982 importation of 2 Mt (2.3 million st). Bentonite production in 1984 increased 20% in volume and 25% in value over the previous year. This suggests improvement in the drilling industry and an increase in demand for iron ore pelletizing grades. All in all, the industrial mineral industry is alive and well. And it shows signs of great improvement in the next few years. Many thanks to those industrial mineral technical committee members for their assistance in assembling this industrial minerals review: M. F. Dibble, H. W. Allen, G. H. Gallup, S. G. Ampian, D. W. L. Spry, H. G. Fleshman, and L. J. Czel.

Jan 5, 1985

The objective in control blasting is to reduce overbreak to control the final pit wall slope, shaft, drift, ditch, bench, etc. to the final planned excavation limit.

Jan 1, 1990