Search Documents

By Türker Hüdaverdi, Özge Akyildiz

"Efficiency of blast operations depends on fragmentation, overbreak, muckpile profile anddisplacement, vibration, airblast, flyrock and damage to wall or slope stability. To provide all these conditions at the optimal level, determination of rock mass properties (in-situ block size, joint spacing and orientation) is the very first step during design stage of rock blasting. Image analysis software is used not only to determine the fragmentation level of muckpile but also to characterize the bench face. In this study, an image analysis software was used to determine apparent block size of bench face and to measure blast fragmentation of muckpile. The source of errors and the vital points to be taken into consideration were explained for bench face characterization andfragmentation measurement. Since it provides much better results than previous techniques and it is not intrusive to production process, image analysis technique is considered as one of the most efficient and preferred way for fragmentation analysis. Besides these advantages, there are some weak points of image analysis software. Lighting is one of the most important factors for photographs captured for in-situ block size analysis and fragmentation analysis. Lighting determines shadow formation. In an ideal image, particles are clearly delineated by soft shadows. If shadows are too strong (dark), analysis suffers. Appropriate scale should be replaced onto blast muckpile during site measurements. The location of the scale in image affects the results of analysis. Also, the densityand orientation of discontinuities should be considered during application of image analysis technique to characterize bench faces. In this study, image analysis software was applied in thesandstone, limestone quarries of Istanbul region and an open pit boron mine. All image analysis, evaluations and results were made based on the site measurements."

Jan 1, 2017

By M Gabbitus, B Young, T Lukins, M Slater

This paper details the implementation of a new type of grade control system at the Black Star open cut mine in Mount Isa, Queensland. It explores the site requirements for grade control, what as previously in place and what the site required moving forward. It also details some of the features of the system installed and why it was chosen over other grade control systems available. Black Star open cut mine has been in operation since late 2004, and was developed to extract the surface extents of the Ag-Pb-Zn mineralisation previously mined in the Isa Lead Mine. Black Star is currently mining seven distinct orebodies in and around active void hazard zones and hence, its grade control requirements are very detailed and complex. The implementation of a new system to manage the model update and block out processes was, therefore, of critical importance to the site and required a detailed understanding of the requirements of the entire mining team from drilling through to geology, survey and production. Having previously run the grade control process using site specific æblack boxÆ scripts and macros, Black Star needed to implement a more open, auditable and flexible system, which allowed the geologists to control the process and make strategic changes as the situation demanded. MineSightÆs Axis Grade Control, with its flexible, generic framework for managing the process, met these demands. Being an out of the box solution that requires minimal setup and training was also a key factor in the decision to use it.CITATION:Lukins, T, Slater, M, Gabbitus, M and Young, B, 2012. The introduction of axis at Black Star Open Cut, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 71-74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By T. D. Jones

MUCH the same story can be told for the lead industry for the year 1945 as for the three previous years. In response to inquiries as to new developments, invariably the answer has been, "No new developments-our men either too busy with the man-power problem or trying to get production out." Time and efforts of industry have been concentrated for the most part on war or readjustment problems. Now that V-E and V-1 day have passed, the lead industry can justly be proud of its record in World War II. As in previous wars, lead played an important role and one of its most spectacular uses was in the production of the atomic bomb. We read that the part lead played was rather obscure, but as a protective agent, lead played a most significant role. "Since the materials in the Pile Plant are intensely radioactive, all storage and handling must be done behind thick concrete walls or lead shields. The material is never seen and all operations are auto matically controlled by a foolproof remote control system especially designed for this purpose." (Chews. & Met., Sept. 1945.) When our armies invaded the European theater of war and made a landing on Normandy beach, gasoline and oil for the motive power were furnished through miles of armored lead pipe. This amaz-

Jan 1, 1946

By F. M. Zafar Kaifi

Magnesite producing companies rely on high grade purity MgO. The mineralogy of magnesite has a significant impact on the manufacturing of magnesite bricks. The manufacturing process of bricks companies utilizes 90% magnesite from 85%~90% MgO. The main objective of the magnesite bricks was to utilizes the indigenous raw material available in bulk quantity. With better under-standing of chemistry of the mineral species and strict control of bricks manufacturing/processing conditions can be better produce efficiently, a low cost high quality bricks with minimum detrimental environmental impact.

Jan 1, 2014

By Michael E. Henderson

Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. This particle degradation report is a summary of the particle distribution data obtained at the HTRF for the period 26 November 1982 to 1 October 1983. The testing covered herein is for coarse Pittsburgh Seam coal in the 6-in (150 mm) and 12-in (300 mm) pipelines, at velocities ranging from 5 to 18 ft/s (1.5 to 5.5 m/s), and at concentrations by weight ranging from 15 to 55 pet. Particle size distribution samples were taken systematically throughout the testing.

Jan 1, 1985

"Real-time, on-stream analysis of the metal content of process slurries is an essential prerequisite for process monitoring and advanced control of mineral processing circuits. On-stream X-Ray Fluorescence (XRF) sensors for base metal applications are available commercially and form the basis of many plant monitoring circuits. To date, these commercial technologies have been insufficiently sensitive to measure precious metals such as gold and platinum group elements, typically present at part-per-million (ppm) and sub ppm levels. CSIRO has developed a novel X-ray based technology, called UltraGold, which enables detection of gold in slurries on a real-time basis with a precision below 100 parts-per-billion. This technology is based on the use of advanced X-ray optics, extensive Monte Carlo computer modelling for analyser design, high accuracy X-ray spectrum fitting where the X-ray intensities are matrix corrected. In this paper, we will introduce this technology and discuss the results of a proof of principle study performed in the laboratory with plant slurries (tailings and concentrate) from an Australian beneficiation plant. Finally, we will discuss further planned improvements. As projected grades in (gold) mining around the world fall and several large-scale mines approach the limits of their economic reserves, this method can enable significantly reduced operating costs by rapid analysis to improve circuit efficiency and hence improve recovery significantly.INTRODUCTION This paper describes a study undertaken to explore the feasibility of applying CSIRO?s UltraGold XRF technology to the on-stream measurement of gold in process slurries. The provision of rapid, accurate information of gold grade in feed, tailings and concentrate streams would facilitate significantly improved process control and early detection of plant upsets, resulting in substantial cost-savings. CSIRO have patented X-ray fluorescence (XRF) techniques for the analysis of key elements in slurries present at part-per-million (ppm) and sub-ppm levels. Conventional, commercially available on-stream XRF instruments generally have detection limits in the tens of ppm range, precluding their use for analysis of elements like gold that are mined and processed at much lower concentrations."

Jan 1, 2017

By F. Seymour

A dynamic programming algorithm is presented that takes a series of nested phases, a fixed mining rate schedule, a fixed plant production capacity schedule, and finds the mining and cutoff grade sequence that maximizes the Net Present Value. This tool allows the Mining Engineer to quickly look at project sensitivity to various production capacities, commodity prices, and costs. A description of the algorithm is given along with examples of how it has been used at Newmont.

Jan 1, 1995

By James R. Miller

Recent experience over extensive areas of the Basin and Range Province has demonstrated the importance of the basin's (valley's) geology and geomorphology in locating large quantities of good-quality aggregate. First, a geologic map depicting basic geomorphic-geologic units in a valley is made in the office from aerial photography. Next, derivative maps are made from geologic maps and field-derived information such as parent rock type, source area and depositional environment, relationship to adjacent deposits, and Quaternary geologic history. Studying the derivative maps leads to selection of test sites for potential deposits of high-quality aggregates. Subsequent field studies provide more detailed information about geologic processes and samples for laboratory testing. Combining all information allows the characterization of aggregate potential of very large areas. Favorable areas can be further tested. This phased approach has proven to be cost effective. The methodology used in mapping and characterizing basinfill deposits is applicable over much of the western United States. Map units were developed by focusing on the predominate geomorphic process, grain size, cementation, and relative age. The resulting functional map units are of use to engineers and planners. This study led to many conclusions, including the fact that the best quality basinfill aggregates are found in selected alluvial fan deposits and Pleistocene lakeshore deposits. The best quality aggregates are derived from Paleozoic carbonate and quartzitic parent materials that can also provide high-quality crushed-rock aggregates.

Jan 1, 1987

By Robert T. Mann

This paper is one of a series being prepared for and published by the United States Bureau of Mines on the quarrying, crushing, and grinding of limestone for cement manufacture. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total coats. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. B. Thoenen, mining engineer of the Bureau of Mines, in the preparation of this paper.

Jan 1, 1933

By Zhang Chuanfu, Li Shixiong

"In the electrolysis electrodeposition or electroplating of aqueous solution of copper, lead, zinc, nickel, manganese etc, with the increase in cathodic over potential the reducing rate of metal and the cathodic current efficiency increases and the deposit becomes more compact and smooth. According to this principle, a method and equipment of the auto-control of electrolyte quality is invented. The industrial application shows that this method turns the experienced operation into auto-control. The quality and quantity of metal is improved greatly and the consumption of electric energy is reduced.In the electrolysis, electrodeposition or electroplating of aqueous solution of copper, lead, zinc, nickel, manganese etc, usually organic additives are added according to the state of cathodic deposit according to experience. This traditional and experienced operation, often lead to that the quality of additive is not optimum which affects the quality and quantity of metal and increases the consumption of electric energy. To counter the controlling problem of the quantity of additive, the authors have invented a corresponding equipment of the auto-control of electrolyte quality [1], it has found application in industrial practice."

Jan 1, 2000

By C. C. Harris

The two best known graphical methods for presenting and comparing comminution data are obtained by linearising the Gates-Gaudin-Schuhmann and the Rosin-Rammler size distribution equations. It is shown that the Gates-Gaudin-Schuhmann equation can cause excessive congestion in the 50 per cent oversize range and that, overall, the Rosin-Rammler is a better procedure. Examples are given

Dec 1, 1971

By R. J. Piniazkiewicz

Talc orebodies are mined in Asia, Australia, Europe, North America, and South America. Operators in North America must be efficient quality suppliers to thrive in a talc market in which many overseas suppliers have advantages such as lower hourly wages, shorter distances to ports, and less government regulation and intervention. Continuous improvement through teamwork and innovation is needed in the following areas to thrive amidst worldwide competition: 1) Maximization of the in-place value of ore. 2) Research and development to yield new processes and products. 3) Safe productivity. 4) Involvement in legislative processes. 5) Wellness programs to lower health care costs.

Jan 1, 1993

and would also contribute to the post-war employment. -As far as the future is concerned, I doubt whether any of the present geophysical methods will ever be developed to directly indicate ore. However, the geochemical methods and certain combinations between chemical and geological methods now used might be the answer to our prayers for direct and more definite methods of determining the quality of the ore or its relative metal content. Geochemical and spectrochemical analysis of minute content in ground waters, in soil or in plants and trees, living or dead, will be extremely important and I would venture to predict that in the very near future each mining or exploration company and each assay oflice will have its own spectroscope equipped for accurate chemical analysis, not only to guide the daily work in the mine, but also for identifying ores as well as for guiding exploration, geological mapping and the evaluation of geophysical indications. These methods, although they are still in their infancy, promise very much for the future. Radioactivity methods could also be helpful when sufficient facilities for radioactivity determination can be made available. They have already been used to a great extent in oil exploration and experiments have shomn great promise for ore exploration also. As for future surveys of large areas, the exploration for physical contrasts will be made from the air, using aeroplanes, helicopters, etc. Already electrical and magnetic methods have been designed whereby the instruments are carried in the aircraft and by automatic recording the location of anomalies is made in a simple enough manner. It should be possible in this way to cover, say, a square mile in an hour. Later Discussion Replies to Dr Lundberg. J. B. Macelwane.*—Someone has said that if a person knows his subject well enough he can explain it in words of one syllable. The point is well taken and I think the converse is also true. If a person cannot explain a subject clearly in simple words, it is either because he has not sufficient command of the language, or he is not master of his subject. Now it is obvious, it seems to me, that the remedy for both of these unfortunate conditions lies not in less education, but in more. If Dr. Lundberg has met geophysicists who confused and discouraged prospective clients by their inability to talk the language of the mine owner or of the mining engineer or geologist, the fault most probably lay in the geophysicist's lack of sufficient training; but it may also have been the want of ordinary common sense, which no amount of education can supply. It is hard to understand the position taken by Dr. Lundberg. Does he regret his own extensive training? noes he wish to say that he would have had greater success in geophysics if he had been only a mine hand with an instrument and a rule of thumb? As a matter of fact, I find it rather difficult to account for his presentation before this Committee on Geophysics of an emotionally distorted picture of the Report of the Committee on Geophysical Education, after the lapse of an entire year since the Report was read and discussed in its proper place, unless he honestly thinks he is handicapped by his knowledge and training and wishes to warn the whole profession against a similar fate. I regret that I am obliged to disagree so emphatically with Dr. Lundberg's thesis— but I believe it would be dangerous if left unchallenged, both because of the inaccurate statements it contains concerning the recommendations made in the Report and because of the ultimate discredit that would be bound to fall upon genuine geophysics if Dr. Lundberg's recommendations were extensively followed out. S. F. Kelly.*-—The argument that a science and its practitioners can be improved by debasing the standard of educational preparation is indeed a strange argument to come from the pen of a man with the education of Dr. Hans Lundberg. In criticising the Committee report, moreover, he has to a certain extent set up a straw man to belabor. The statement that the Committee report recommends that

Jan 1, 1946

and would also contribute to the post-war employment. -As far as the future is concerned, I doubt whether any of the present geophysical methods will ever be developed to directly indicate ore. However, the geochemical methods and certain combinations between chemical and geological methods now used might be the answer to our prayers for direct and more definite methods of determining the quality of the ore or its relative metal content. Geochemical and spectrochemical analysis of minute content in ground waters, in soil or in plants and trees, living or dead, will be extremely important and I would venture to predict that in the very near future each mining or exploration company and each assay oflice will have its own spectroscope equipped for accurate chemical analysis, not only to guide the daily work in the mine, but also for identifying ores as well as for guiding exploration, geological mapping and the evaluation of geophysical indications. These methods, although they are still in their infancy, promise very much for the future. Radioactivity methods could also be helpful when sufficient facilities for radioactivity determination can be made available. They have already been used to a great extent in oil exploration and experiments have shomn great promise for ore exploration also. As for future surveys of large areas, the exploration for physical contrasts will be made from the air, using aeroplanes, helicopters, etc. Already electrical and magnetic methods have been designed whereby the instruments are carried in the aircraft and by automatic recording the location of anomalies is made in a simple enough manner. It should be possible in this way to cover, say, a square mile in an hour. Later Discussion Replies to Dr Lundberg. J. B. Macelwane.*—Someone has said that if a person knows his subject well enough he can explain it in words of one syllable. The point is well taken and I think the converse is also true. If a person cannot explain a subject clearly in simple words, it is either because he has not sufficient command of the language, or he is not master of his subject. Now it is obvious, it seems to me, that the remedy for both of these unfortunate conditions lies not in less education, but in more. If Dr. Lundberg has met geophysicists who confused and discouraged prospective clients by their inability to talk the language of the mine owner or of the mining engineer or geologist, the fault most probably lay in the geophysicist's lack of sufficient training; but it may also have been the want of ordinary common sense, which no amount of education can supply. It is hard to understand the position taken by Dr. Lundberg. Does he regret his own extensive training? noes he wish to say that he would have had greater success in geophysics if he had been only a mine hand with an instrument and a rule of thumb? As a matter of fact, I find it rather difficult to account for his presentation before this Committee on Geophysics of an emotionally distorted picture of the Report of the Committee on Geophysical Education, after the lapse of an entire year since the Report was read and discussed in its proper place, unless he honestly thinks he is handicapped by his knowledge and training and wishes to warn the whole profession against a similar fate. I regret that I am obliged to disagree so emphatically with Dr. Lundberg's thesis— but I believe it would be dangerous if left unchallenged, both because of the inaccurate statements it contains concerning the recommendations made in the Report and because of the ultimate discredit that would be bound to fall upon genuine geophysics if Dr. Lundberg's recommendations were extensively followed out. S. F. Kelly.*-—The argument that a science and its practitioners can be improved by debasing the standard of educational preparation is indeed a strange argument to come from the pen of a man with the education of Dr. Hans Lundberg. In criticising the Committee report, moreover, he has to a certain extent set up a straw man to belabor. The statement that the Committee report recommends that

Jan 1, 1946

By J. A. Orr

The details connected with the mining and subsequent handling of Creighton ore were fully covered in a paper presented to the Institute in 1920. The following brief notes describe certain phases of the present practice and show wherein it differs from the practice at that time. These may be summarized under the following headings. (a) Recovery of pillars. (b) Drawing the ore. (c) Change from sub-level tramming to branch-raise system. (d) Chute construction. The present stoping practice is the same as formerly, i.e., fiat-backed shrinkage stopes of 60-foot width, between rib pillars of 15-foot width, extending from the footwall to the hanging-wall. Formerly, when these stopes were completed to the stopes above, they were drawn empty of broken ore, and the 15-foot rib pillars were caved into the stopes and drawn off through the same chutes as were used to draw the ore from the stopes.

Jan 1, 1926

By Cory Bolen, Nadav Bar-Yaakov, Eric Zimmerman, Gregory Raines

The Chimney Hollow Reservoir Project broke ground in August 2021, constructing the tallest Asphalt Core Dam in North America, intending to improve reliability of drinking water supply to Northern Colorado communities. Aiming to expedite and streamline the geological mapping process in the tunnel, Stantec’s teams have developed a mobile and web-based GIS application for digital mapping input and rock mass evaluation, allowing real time decision making for assigning tunnel support class and resulting in a faster more efficient process. The following article presents and demonstrates the GIS mobile and web application-based process, the mapping results and review additional uses of the database created.

Jun 13, 2023

By A. E. Wells, H. O. Hofman, R. P. Reynolds

A Discussion of the Paper of H. O. Hofman, R. P. Reynolds and A. E. Wells, read by title at the London Meeting, July, 1906 ; presented at the New York Meeting, April, 1907, and printed in Bi-Monthly Bulletin, No. 13, January, 1907, pp. 37 to 52. GEORGE A. PACKARD, Boston, Mass. (communication to the Secretary*) :-The very interesting results obtained by Prof. Hofman and his assistants came to my attention when I had temporarily assumed charge of the metallurgical department of the Missouri School of Mines, and had found it, pending the completion of a new building, lacking a furnace in which to roast ore preparatory to the customary lead blast-furnace run. An attempt at lime-roasting had been already determined upon, but the use of a charge which would make a slag of definite composition was a new idea. The results following were obtained by Messrs. Aubrey Fellows, J. C. Long, E. R. Wash, and Dr. T. C. Tseung, under my supervision. It is regretted that the data are not more complete; but the work was done simply incidentally to securing the desired ore for the blast-furnace, with no idea of obtaining any results of especial interest. It is submitted because of the metallic lead obtained, no notice of which has been seen elsewhere. The ore was an aggregate of several lots of concentrates, apparently from Missouri ores. The analysis follows, with that of the limestone and sandstone used, as far as made:. Ore, SiO2, 3.04; Fe, 0.77; CaO, 2.53; Pb, 68.74; Zn, 5.77; S, 13.9 per cent.; limestone, SiO2, 1.0 ; CaO, 54.35 per cent.; sandstone, SiO2, 99.8 per cent. The converter was made in the shops from a sheet of No. 14 iron riveted in the shape of a truncated cone, 20 in. in diameter at the top, 15 in. at the bottom and 22 in. high. A grate of No. 8 iron, 17 in. in diameter, with 130 s-in. holes placed at about 1.25-in. centers, was held in place by the shape of the

Jul 1, 1907

By C. D. M. Chisholm

IN discussing stope filling, or backfilling, at the Sullivan mine, at Kimberley, B.C., a brief description of the problem will first be presented. The Sullivan orebody is a replacement in quartzite, with the ore con-forming, for the most part, with the bedding. The dip of the vein, apart from local irregularities, averages about 15 degrees near the outcrop in the southwest section of the mine, and steepens to almost 40 degrees at the northeast end of the mine. The thickness varies from a few feet to over 200 feet at the widest sections. The mineable length along the strike has averaged about 4,000 feet between the 4,600 and 3,900 levels-the section under discussion in this paper. To date, 28,000,000 tons of ore have been mined by the room-and-pillar method. Prior to 1930, all ground opened up had been supported by ore pillars, left during mining operations. From that time, the recovery of the ore from these pillars has been given serious consideration. Backfilling, as being carried on today, is the result of this study and is being done for two reasons: (1) to allow extraction of the ore pillars, and (2) to minimize subsidence of the hanging-wall rock, except where forced caving is found desirable. PRELIMINARY DEVELOPMENTS LEADING TO BACKFILLING When the Sullivan orebody was first opened up, early in the century, there appeared to be low-grade sections of the vein sufficient in extent to serve as permanent support for the roof. However, as mining extended into sections of the vein that showed continuous ore over greater areas, wooden cribs, filled with waste and low-grade ore, were erected. In some stopes, these cribs were as large as 40 ft. by 100 ft. in plan and from 50 ft. to 60 ft. in height, but it was soon realized that this method of support was inadequate. As mining progressed, it was found necessary to leave ore pillars, which eventually became the sole system of support. At first, these pillars were left at irregular intervals, but later they were laid out at definite locations on the mine plans, and these locations were adhered to as closely as mining would permit.

Jan 1, 1941

By P. Jurovcik, D. Yantek, D. Ingram

The National Institute for Occupational Safety and Health (NIOSH) identified hearing loss as the most common job-related disease in the United States in its 1996 National Occupational Research Agenda. Previous studies by NIOSH have shown operators of surface drill rigs without cabs are commonly exposed to A-weighted sound levels exceeding 90 dB. During hammer-drilling, A-weighted sound levels exceeding 100 dB were recorded at the operator station. NIOSH collaborated with a local drilling company to design and install a partial cab between the operator and the drill steel in an effort to reduce the sound level at the operator station. Sound level measurements in the field show the partial cab reduces the A-weighted sound level by 5-9 dB at the operator’s left ear and 2-5 dB at the operator’s right ear while hammer-drilling. This paper will briefly discuss the preliminary design of a cab and the testing of materials for construction of the prototype. Explanation of the ideas behind the prototype design and fabrication will be covered. Finally, the field test method and results will be discussed in detail.

Jan 1, 2007

By K. E. Stanfield

The oil yields of sections of Green River oil shale in Colorado, Utah, and Wyoming are presented as part of a continuing project to determine oil-shale reserves in the United States. Oil-yield logs, based upon analyses obtained from 1945 through 1952, are presented to show the thickness and richness of 202 sections of Green River oil shale. The logs are based on analyses of approximately 20,500 samples, representing 179,000 feet of shale, which were made by the Bureau of Mines, and upon analyses, representing approximately 26,000 feet of shale, which were made by other agencies. The samples consisted of cores from a Bureau of Mines coring program in U. S. Naval Oil-Shale Reserve 1, Garfield County, Colo., and cores, drill cuttings, and channel samples provided by other agencies, chiefly oil companies. Most of the samples of oil shale from Utah and Wyoming were derived from oil-well drilling operations. As a result, the oil-shale sections were widely scattered and were not extensive or reliable enough to be representative of the significant deposits of Green River oil shale in these States. The oil-shale sections for Colorado, however, were more comprehensive, and a number of the sections were used in a previous report as a basis for estimating oil-shale reserves in Colorado. The present report does not give estimates of oil-shale reserves but is limited to presentation of oil-shale analyses that may be used for future reserve estimates. Other sections of Green River oil shale are being analyzed, and the results will be published in subsequent reports.

Jan 1, 1954