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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 A. Newman, A. Brickey

Although some of the prevalence of openpit production scheduling software can be explained by the predominance of openpit mining throughout the world, other factors have led to a lag in corresponding underground software. We explain mathematically why underground production scheduling is more difficult than its openpit counterpart and provide directions for research in the underground scheduling arena.

Jan 1, 2014

By H. EI-shall

In this paper, the results of a fundamental study involving zeta potential and turbidity determinations of solid suspensions are discussed. Illustrations of how these results are utilized to design field applications of solid grade polymers to clarify mine drainage water are presented. Other applications in different industries are also reported. The operational and economical advantages are examined.

Jan 1, 1994

By R. A. Matuszak

U.S. Government sponsored studies proclaim large reductions in surface mine productivity. Consulting studies place a large share of the blame on increased governmental regulatory activities and on inexperienced, improperly train people. Union rules, which allow indescriminate bidding for job openings, seem to be a major factor causing the lack of experience in spite of elaborate training programs.

Jan 1, 1982

By J. Edwards

A new, world class dump leach, solvent extraction, electrowinning plant for the recovery of copper comes on line in Chile. CODELCO-Div. Chuquicamata has added a new facility to their operations located in northern Chile. The plant demonstrates many unusual features including: underground collection of leachate, high copper tenors, extensive use of plastics and special corrosion resistant alloys.

Jan 1, 1989

By L. P. Hendriks

Consolidated Murchison, the only antimony producer in South Africa, is situated in the northeastern part of Transvaal. Phalaborwa, an important copper/phosphate mining town is situated about 60 km to the east of Consolidated Murchison, on the border of the Kruger National Park. The mine is jointly controlled by Johannesburg Consolidated Investment Co. Ltd. (JCI) and Anglovaal Limited.

Jan 1, 1998

By R. L. Guerguerian

Critical fasteners are described as they apply to the specification, manufacture, and assembly on large grinding mill bolted joints. The importance of adequate design methods, related joint diagrams and pivot analyses, and special emphasis on the quality of manufacturing and the tightening procedures in the field, are discussed; all in an effort to ensure high availability plant operation.

Jan 1, 2001

By Bob Snashall

"We could blow that damned fort out of existence if we could run a mine shaft under it!," claimed one Union soldier eyeing Bobby Lee's Petersburg defense line protecting Richmond and Jeff Davis. Puncture the line, take the hill behind, and the Confederate capital would celebrate Yankee jubilee, 1864. That was June. At 4:15 am, July 30, mine boss Henry Reese, sergeant, 48th Regiment, Pennsylvania Volunteers, gingerly entered the mine, dark and muddy. Something had gone wrong. The mine, set to go off at 3:30, hadn't exploded. It had to be checked. The main mine gallery, 1.5 m high x 1.4 m wide (5 x 4 ft) narrowing at the top to 0.6 m (2 ft), forced Reese into a tuck run. Some¬where up there in that 155 m (511 ft) stretch running 6 m (20 ft) under the rebel works, moisture may have doused the charge. Or maybe a fuse splice went awry. Or maybe there was live fire steaming like a locomo¬tive towards 3.6 t (4 st) of black powder. Perhaps now Reese wished this sprint was shorter. For the mine boasted a record break¬ing distance in military annals. Lieut. Col. Henry Pleasants Credit goes to Lieut. Col. Henry Pleas¬ants, commander of the 48th, who overheard the soldier's claim for what a mine could do. In peacetime, Pleasants had been a railroad engineer working on the Sand Patch Tunnel. He later switched to mining, working for the Philadelphia & Reading Coal & Iron Co. He even married the daughter of the editor of The Miners Journal. Grieving over his wife's early death, Pleasants plunged into the ven¬ture of war. This Union officer took the mine idea to the brass. Headquarters was less than enthu¬siastic. "The chief engineer of the Army and the rest of the regular Army wiseacres said it was not feasible," Pleasants wrote to his uncle. The pros scoffed, ticking off a list of horribles: No mine has ever gone that far, men will suffocate and be crushed, the rebs will countermine, the men will be trapped. Still, Pleasants eked out a signal to proceed. In the meantime, the miners of the 48th had commenced to dig anyway. It was like the 48th to proceed against the odds. The 48th Pennsylvania Volunteers The 48th had been recruited from Penn¬sylvania's Schuylkill County, anthracite coal mining country. The mines had been torn with strife over wages. Strikes and rioting were prevalent. Murder was not unknown. This "Buckshot" resistance centered in Pottsville, PA. It forced the governor to call in troops. Coal was in high demand to run the war machine. Pennsylvania operators worried that a military draft would stir up violence, closing the mines altogether and further shift¬ing business to emerging Illinois mines. Men lit out for the western gold fields in the tens of thousands. Secret societies bred in the mining camps invited draft agents to dance at the end of a rope. Jobs threatened by cheap, victorious South¬ern labor were one warning intended to get immigrant miners interested in the war. Operators gave miners time off to help de¬fend Philadelphia during Lee's thrust to Gettysburg. Even so, the draft spawned new violence and troop intercession. Soldiers were not welcome. The dust had barely settled when into this Pennsylvania "minefield" marched the 48th on a recruitment drive. The 48th had been in Lexington, KY on guard duty. When it came time for the regiment to pull out, the townspeople had prevailed upon authorities to extend the regiment's stay. Finally ordered to move out, the 48th was feted by a hanky-waving, tear-dropping send-off to the lyrical lament Auld Lang Syne. And Kentucky fancied itself to be rebel. Striding smartly into the Pennsylvania coalfields, the 48th attracted 400 recruits and marched off under regimental colors specially made by the proud citizens of none other than Pottsville, PA.

Jan 1, 1989

By E. J. Garrison

Discussion by E.J. Garrison A.C. Noble presents a clear and concise summary of the factors pertinent to a competent reserve evaluation of a mineral occurrence. However, I believe that he confuses the difference between a resource and a reserve. By definition, a reserve estimate includes all known economic, legal, mining, metallurgical and environmental factors impacting the recovery of the product(s) found in the deposit. A resource estimate, however, is an estimate of what is there - what is available for exploitation and should not include economic and other considerations. Only after defining the resource, its extent, location, physical and chemical properties, can an intelligent selection process begin of the extraction and processing technologies most appropriate to the circumstances encountered. The early and almost certainly inappropriate application of these often cookbook choices has probably lead many companies to walk away from good properties. (How many mines have been found in others rejects?) An example of the process is the early selection of metallurgical samples, after encouraging values are found in a few holes or surface samples, in an attempt to determine the economics of the prospect. Unfortunately, the sampler does not know how representative of the occurrence the sample is because he does not know what the deposit looks like. As a consequence, the property becomes saddled with a bad metallurgical sample that is often inappropriately used in evaluating the deposit which it does not represent. Reply by A.C. Noble E.J. Garrison asserts that I confuse the difference between a resource and an ore reserve. In fact, this paper was motivated by the observation that resources and reserves are almost universally confused throughout the industry. While Garrison is concerned that too-early consideration of engineering, metallurgical and economic factors will result in dropping properties too soon, some issues that must be considered include: •The purpose of exploration is to discover ore reserves, not to discover resources. •Ore reserves are always smaller than resources. • Decisions on exploration expenditures must be made based on the expectation of the quantity of ore reserves that will ultimately be defined. Noble's Fig. 2 can be used to give guidance as to when it is appropriate to begin reserve calculations. When exploration enters the "flat" portion of the curve, representative samples can be selected for metallurgical studies and appropriate mining methods chosen. It is at this stage that we know enough about the deposit to make intelligent choices of representative samples and recognize constraints on mining caused by the deposits shape, environment and physical properties. Once the appropriate technologies have been chosen, then their cost can be estimated with reasonable accuracy. Early entry of economic and process factors gives the false appearance of reserve status to the resource estimation. It would be more informative and less subject to abuse and misunderstanding if resource calculations were made at a number of cutoff grades. The cutoff grades should be chosen to cover the range of grades found in practice in existing operations of similar type. This would emphasize the open nature of resource estimates and encourage creative evaluation of mining and process technologies. It does not preclude the use of economic, environmental and recovery technology factors in deciding the advisability of continuing exploration expenditures, but would highlight their speculative nature. It is thus hoped that decisions on the future of the deposit would not be made on the presumed suitability of a given technology but on the actually known reality. I agree that resource estimates should be reported as a range of cutoff grades. Since reporting at a cutoff implies application of underlying economics (even by analogy to similar properties), however, it should be clearly stated that resources do not consider economic, mining or cost factors, and that ore reserves will be substantially less. The dilemma of the explorationist is that until the continuity and limits of ore-grade mineralization have been established, it is difficult to make quantitative estimates of either resources or ore reserves. Further industry discussion is needed regarding standards for disclosing early exploration information in such a way as to fairly represent the potential of an exploration property.

Jan 1, 1995

By Tan Zhenxiang

INTRODUCTION Koolyanobbing is an open cut iron ore mine, which is located in Yilgarn region of Western Australia. To prevent the operators from suffering silicosis diseases and protect the air from being polluted, a series of dust control measures have been taken. These measures include ventilation and dust control system for sample preparation shed, dust collecting system for drill rig, dust suppression system for ore processing plant, dust control for haul road. The details related to individual dust control measure are dealt as follows. SAMPLE PREPARATION SHED DUST CONTROL The sample preparation is one of the major dust sources at Koolyanobbing. The activity is being carried out at the sample preparation shed. It typically needs to go through the following stages, that is, crushing, splitting, drying and pulverising. The amount of dust generated from crushing and splitting is mainly determined by the moisture content contained in the pre- pared sample. A significant amount of dust is generated at the sample pulverising stage due to cleaning sample bowl with com- pressed air. To protect the sample preparing personnel's health and make the dust level in the air meet the requirement from the health and safety authority, a central ventilation and dust control system has been installed at the sample preparation shed. As shown in Fig. l, the system consists of suction heads, suction lines, dust collector and vacuum fan. The fan creates vacuum environment in the system, therefore the dust is drawn into the dust collector through the suction heads and suction lines. The dust collector is of fabric filter. When the dusty air comes to the filter, the dust in the air is collected and retained on the surface of the filter while the clean air passes through and enters the atmosphere. The retained dust is blowed out by the pressured air pulses and deposits into the dust bin underneath the filter. A time relay device is used to control the cleaning time and the cleaning interval. DRILL RIG DUST CONTROL A hydraulic percussion drill is used to drill blast holes. To carry out the drilling operation properly and efficiently, the cut- tings are being flushed out of the hole by the compressed air. In order to prevent from the fine particles in the cuttings escaping to the air, a dust collector is attached to the drill. The collector mainly consists of suction head, cyclone and bag filter. Refer to Fig. 2. The suction head is installed at the lower end of the feed beams and is movable. The moving range is up to 250 mm. It is not only used to restrict the cuttings, but also used to prevent water from entering the filters when drilling wet hole. A 406 mm diameter primary cyclone is used to separate the heaviest particles in the cuttings. It is also used as blast holes sampling equipment. One part of the dust particles are collected by a sample bag through a splitter attached to the end of the cy- clone. The rest of the particles fall down to the ground through the closing rubber. The bag filter is driven by a hydraulic motor (1). It is used to collect the lighter particles in the cuttings. The filtering area is 16 m2 and the dust separation efficiency is up to 99.9%. The working principle of the filter is demonstrated in Fig. 3. When the rock drill (9) flushing is turned on, the pressurised air from the compressor is directed to the rock drill and to the pres- sure switch (10). The pressured air will open the pressure switch to de-energise and close the solenoid valve (4) The pressure affecting the cut-off cylinder (5) keeps the exhaust port flap open. When the flushing valve (8) is closed, the pressure affecting the cut-off cylinder disappears and the internal intake opening flap is closed by a spring. The pressure also ceases to affect the pressure switch and the spring switches the contact to the point 2. The time relay (11) is now activated and gives a 0.5 second current impulse to the solenoid valve and keeps the current cut off for approx 8 seconds. When the solenoid valve is live, it opens and lets an impulse of pressured air to the filters (2). These impulses will clean the filters.

Jan 1, 1997

By Christy Z. Lueders

Introduction More and more women engineers are joining the traditionally male mining industry. Are they successful? Do they encounter special problems? How do men in mining respond? How can the mining industry effectively use its female resources? What contributes to the success of a woman in mining? What can male engineers do to ease the entry of female professionals into the workforce? An STM survey conducted last spring provided some answers to these questions. All BS graduates in mining, mineral engineering, and extractive metallurgy from 1960-1979 were surveyed. Nearly 60% of the female graduates, from 17 universities, completed questionnaires. The women were asked why they chose mining, how they relate to predominantly male co-workers, what job skills they have gained, and what areas of work they most enjoy. They were also asked how problems of a two-career family are solved. Data were gathered on salaries, titles, specialties, and products handled. Respondents, assured of confidentiality, are identified only by title. Many male mining executives were also questioned for their advice to women in mining. Profile of the Survey Participant The "typical" female mining engineer works with coal, is employed by an operating company, feels she works very hard to prove her abilities, does not want to be treated as an anomaly, and someday wants to be an independent consultant. Of the respondents, 44% listed coal as the most familiar product, 12% said copper, and the rest listed products from industrial chemicals to oil. Titles varied widely but women managers are rarely found. However, the majority of the survey population graduated after 1976 and thus lacks substantial experience. Of 102 female graduates, only 25 graduated before 1977. Since then, there has been a steady increase. The American Association of Engineering Societies reported that in 1980 more than 100 degrees were awarded to women in minerals engineering. Education Highly Valued Twenty-two percent of the women surveyed had graduate degrees, 38% planned further education, and 12% listed a PhD as their goal. The majority of graduate degrees are in technical fields. There were only two MBAs. Five women intended to pursue law degrees, and one woman, with a mining engineering degree and an MBA, is a part-time law student. Along with advanced education, the women agree that production experience is needed for career advancement. However, only 28% of the women have worked in production. Many women, especially younger grads, commented that these are the toughest jobs to get. This is a universal complaint, from males as well as females, though women seem to encounter more opposition. Several women mentioned they were small or slight of build and managers tended to shy away from hiring them for production jobs. Two-Career Marriages The most difficult problem for two-career couples is relocation. Whose career takes priority? Fifty percent of the women said transfers or offers would be examined on a case-by-case basis, weighing pros and cons for both parties. The husband's career took priority with 47% of the women; their own careers, with 3%. These statistics conflict with comments from two employee relations managers. Both said most female engineers they've encountered are married to men who follow their wives' careers. Seventy per cent of the married respondents said their husbands were also engineers. Four said their husbands were engineers at the same company. Some male and female engineers met on the job; others joined the company as a "package deal." Both partners being engineers can ease relocation problems, since an area or company offering one spouse a job can often provide a spot for the other. A company may benefit by getting two new hires for the relocation costs of one. Most companies contacted have policies that allow married couples to work at the same division, but discouraged them from working in the same department. With 40% of today's marriages ending in divorce, one risk is that one or both parties may quit. One personnel executive said there were several couples, each spouse in a different discipline, who were work¬ing out very well at his division. However, he recognized the potential for problems if, for instance, one gets promoted and the other doesn't, or salary increases are unequal. The personnel executive said he has actively recruited married couples, and would again, were each person competent.

Jan 10, 1981

By H. J. Handewith

This paper explores the state-of-the-art of mechanical rock drilling and boring methods in use in the year 2000. It covers the basic mechanisms of cutting tool design and outlines the current understanding of related rock fracture methods. It provides suggestions for future research needs and discusses the mining and construction markets that are driving these needs.

Jan 1, 2001

By C. J. Ferron

Gold occurrence in operating plant tailings ranges from gold in solution, fine free gold, gold associated with sulphides/arsenides/tellurides and gold occluded within iron oxides or arsenates and silica gangue. This paper briefly presents various alternatives to reprocess gold tailings, with examples. These include the use of centrifugal gravity separators, CIL, magnetic separation, flotation and pressure oxidation.

Jan 1, 1993

By R. L. Guerguerian

Critical fasteners are described as they apply to the specification, manufacture and assembly on large grinding mill bolted joints. The importance of adequate design methods, related joint diagrams and pivot analyses, with special emphasis on the quality of manufacturing and the tightening of procedures in the field, are discussed in an effort to ensure high availability plant operation.

Jan 1, 2003

By Marina K. Peshkova, Izabell V. Pomorova

Computer modelling system for definition optimal way of in- vestment under condition of diverse directions of activities mining enterprises has been created. The main purpose of paper is to introduce the new scientific approach of finding effective variants of investment for mining industry under free market condition in Russia, it can be also interesting for domestic and foreign investors.

Jan 1, 1996

By D. Royston

A novel low-cost technology is described that treats excavation waters in estuarine environments where water coloration due to humic material is present, along with acidity, turbidity, sediment and salinity. The process treats all the components in the water to produce a clear (color-free) water stream that meets requirements for direct discharge to local estuarine waterways.

Jan 1, 2003

By John A. Christophersen, Adolf J. Jonaitis

Coal flotation applications utilizing column flotation have been shown to improve grade and recovery when compared with traditional mechanical cell flotation. Deister Flotaire Column Flotation Machines have been installed in pilot and commercial coal cleaning applications. Comparative data covering prior and current flotation is presented. In addition, special characteristics covering the Deister air generation system are presented.

Jan 1, 1989

By K. R. Wood, P. M. Blythe, J. A. Finch, M. L. Lavallee

A new analytical approach for characterizing and improving the performance of ball milling is presented. Individual ball mill circuit design and operating variables can be related to overall circuit performance through two distinct parameters for classification and breakage. The ball mill circuit functional performance equation is presented. Applications in the industrial plant and in the research field are discussed.

Jan 1, 1991

By George D. Tikkanen

The world supply of zinc and lead is reviewed. The nature of zinc and lead deposits, production constraints, current production and reserves, new developments, possible future developments, and closures are considered. Lead sup- plies for the future are adequate. Zinc supplies are expected to tighten in the longer term due to growth in zinc consumption and orebody depletion.

Jan 1, 1986

By T. I. Probert, B. W. Burdett, L. B. Hales

Selecting a mineral processing control system from the multitude of offerings can be a formidable task. To assist the plant designer, the material in this chapter includes the advantages and disadvantages of different equipment types, configurations, and control strategies. Selection procedures are detailed, and the importance of each step in the design and selection process is explained.

Jan 1, 1986