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By David L. Kuck

Siderophyle platinum-group metals and sane gold are a thousand times more abundant in metal and chondritic meteorites than in terrestrial or lunar rocks. Type I and II carbonaceous chondrites contain granules of the high boiling point metals W, Re, Mo, Ir and Os. Metal meteorites and the metal fractions of other chondrites contain siderophyle Pt, Pd, Ru, Rh, Os, Ir and Au. Spectra of sunlight reflected from asteroids, when compared with those of meteorites and specific minerals, provide a rough classification and guide to sources of precious platin-group metals.

Jan 1, 1982

By R. L. Grayson, S. B. Bealko, L. L. Chasko, D. W. Alexander

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies, including a fire or explosion, a massive roof collapse, mine inundations or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training.

Jan 1, 2010

By J Hutchings

An essential component to the management of any process is the measurement of key parameters, used to monitor, control, and provide the feedback necessary for improvement. This paper discusses how data collection and analysis can provide a better understanding of the blasting process, as well as additional control and improved outcomes.The drill and blast process involves the generation and use of information at a number of levels. Comparison of historical parameters and results provides a starting point for the development of ongoing blast designs and a baseline against which future results can be compared. The collection of data during implementation provides a quality assurance/quality control (QA/QC) function where potential defects (such as under-drilled or over-charged holes) can be rectified prior to firing. Actual quantities and production rates allow the development of realistic plans and schedules, rather than using inaccurate estimates and targets that lead to unscheduled changes to equipment paths. Over?the past several years there have been a number of technological advances in data collection technology. Drill monitoring instrumentation on blasthole drills provides location information and feedback on rock properties as drilling occurs. Hand held ‘data logger’ technology has also overcome the challenges of working on the bench, such that blasthole measurements can be collected and forwarded directly to the explosive truck. Mine sites are becoming wireless network-enabled allowing the seamless data transfer from the field back to the office, in near real time, as that information is collected. Great strides have also been made in the development of drill and blast software systems which are more user friendly, and yet provide far greater capability to manage the quantity of data generated. The blasting process is critical to the overall mining process and the delivery of a successful blast outcome requires that the blasting process be ‘in control’. The measurement of key parameters can provide the data with which to measure and maintain control of blasting, and allows the validation of performance improvement measures and identification of improvement opportunities.

Nov 8, 2011

By Fengyu Ren, Ruslan Puscasu, Kunpeng Yu, Gideon Chitombo, Liangliang Kang

Weak rock mass and poor flow of material can cause excessive ore loss and dilution in sublevel caving. This paper proposes a method to establish design parameters for an inclined deposit within a weak rock mass and evaluates its effectiveness through a case study. In order to solve the problem of low production capacity and poor safety conditions of sublevel caving mining at the Yingfangzi silver mine in China and to ensure a smooth production from the refractory ore body, it is necessary to select appropriate stope structure parameters. Based on random medium theory of gravity flow and the improved equation of ore discharge in random medium, an end wall drawing experiment is carried out to determine the optimum design and flow parameters. It was observed from the experiment that, due to the influence of the randomness of particle movement, there is a mismatch in the flow parameter measurement. The flow characteristics and distribution of the marker particles are different from that of the tested particles resulting in large drawbody shape distortion. The study finds that the flow parameters obtained by the new method are more practical and account for drawpoint width and recommends that the new method for determining the sublevel stope height is used when the drawbody is a non-standard ellipsoid. The outcomes have shown a significant reduction in the dilution and improvement in the recovery rates, and the safety and efficiency of mining have been greatly improved.

By C. R. Kuzell

GEOGRAPHICAILY the industry of reducing and refining of copper continued to migrate from the .United States during 1931. While this country is losing the predominant position of its copper industry, our engineers still enjoy their pre-eminent position as leaders in the design and operation of the new plants being brought into production in the four quarters of the globe. Progress in the art, as indicated by the construction of the recently completed works, has not been revolutionary. Standard methods have been followed, augmented by novel features in flow-sheets demanded by the results of progress in the art of ore-dressing, and by reason of problems incidental to the peculiarities of the new ores being treated. Design and construction progress has likewise been orderly and without radical departure from less recent practice; new features in primary and secondary equipment being logical developments to provide for special conditions to keep abreast of improve¬ments in accessory apparatus. The new plants are being rapidly brought in without hazardous novelties and for the purpose of yielding the principal ingredient, copper, in as large a volume as it will he possible to market; the old United States procedure. In the meantime the domestic plants are shut down or operating at a very low capacity, threatened with untimely demise unless the metallurgist can extract and develop other valuable products from the ores. International agreements .and tariff protection may be a temporary reviving stimulant, but for many mines the days of profit will be numbered unless the ores can be made to yield as values the ingredients now being discarded. Invisible progress in this direction has been made during the past year, and it is to he hoped that time will prove that the outstanding progress of 1931 was in the development of processes for the ultimate recovery of by-products from copper ores, perhaps even relegating the value of the copper yield to secondary importance.

Jan 1, 1932

By R. D. Irvine

Enhanced concern for protection of the environment and attendant actions by environmental regulatory authorities in support of this concern are influencing to varying degrees the demand and supply of a range of industrial minerals in a number of jurisdictions. These influences take a variety of forms. In this paper, the author seeks to delineate certain broad trends which are occurring relative to industrial minerals and the environment and then, through a series of examples, outline opportunities, developments, and impacts respecting a number of industrial minerals produced and consumed in Canada and the United States.

Jan 1, 1995

By D Mather

Fibre reinforced shotcrete has long been accepted as temporary ground support in both mining and civil tunnel linings. Greater knowledge and understanding of shotcrete as an engineering material and advances in its quality have enabled designers to eliminate the requirement of a second pass lining. The initial shotcrete can be used as the permanent tunnel lining or be incorporated into the final lining design, rather than ignored and considered as sacrificial.For the initial shotcrete lining to become a suitable permanent tunnel lining it must be able to establish and maintain stability over time when subjected to all possible loads. To ensure this, best engineering practices are required during the design phase of the project to analyse; ground conditions including rock mass properties, ground and ground water quality, rock mass loadings, excavation sequencing, and construction methodologies.The increased durability of steel fibre reinforced shotcrete over traditional tunnel support, in the right ground conditions, makes it possible to achieve a serviceability design life of greater than 100 years (as required in most infrastructure projects). By specifying a good quality shotcrete mix and ensuring adequate quality control for batching, fibre dosing, preproduction testing, excavation sequencing, and application control, it is possible to eliminate the requirement of a secondary lining. The properties of a suitable permanent lining must be well established using suffi cient preproduction testing in combination with post application monitoring.A major benefit of steel fibre reinforced shotcrete in ground support applications is the removal of any requirement for workers to work under unsupported ground. Its use can also significantly reduce, if not eliminate, the manual handling associated with placing traditional reinforcement such as lattice girders and mesh. Both of these benefi ts are significant with the ever increasing focus on health and safety.This paper highlights factors that must be considered in the design and specifications to enable an initial shotcrete tunnel lining to become the permanent shotcrete tunnel lining.

Mar 8, 2011

By R. S. Douglas

Introduction The operations of The Granby Consolidated Mining, Smelting and Power Company, L1mited, have always been concerned with the mining of low-grade copper ores. In the fifty years of this Company's existence, nearly 60,000,000 tons of such material has been successfully mined and treated. During these years, many changes in mining practice took place. However, at Copper Mountain, due to the large tonnages of very low grade material, it was realized that something more than changing mining methods would have to take place if these low-grade orebodies were to be mined at a profit and the Company and. its employees enjoy many years of successful operation and employment. Production costs were mounting commensurately with rising taxes and the increasing cost of supplies, labour, freight, and smelting, while the value of the product on the market was not increasing in price to compensate for the higher costs of production. A survey of the mineable ore in 1944 indicated that, of the 12,000,000 tons in the reserves, only 3,500,000 tons was now profitable ore. This reduction in the commercial ore reserves was a serious matter, as it meant that the mine had only two years of life at the profitable shipp1ng rate of 4,800 tons per day. Further, the location in the mine of the orebodies making up the 3,500,000 tons was not suitable for such high production.

Jan 1, 1950

By Paul Shimizu

BHP Robinson contracted Minnovex Technologies to implement a Comdale Expert System at their greenfields operation in Ely, Nevada. The expert system has resulted in a significant increase in tonnage. Other benefits have also been realised, including a reduction in operation upsets (having a positive effect on downstream processes, i.e. flotation) and reduced production variances between crews. The expert system is written in a unique manner using trend based logic with minimal hard limits. The result is a robust system that requires minimal operator supervision while producing very high results. The development, success and acceptance of the system can be attributed to the strong team that was assembled for this project. The team not only consisted of BHP Metallurgists and Minnovex but most importantly included operations.

Jan 1, 1998

By I. E. Odom

The physiocemical properties and industrial uses of the clay mineral montmorillonite are reviewed. Montmorillonite is the most abundant species of the smectite clay mineral group and is the predominant mineral composing bentonite deposits. The crystal structure, chemical composition, exchangeable ion type, and small crystal size are responsible for several unique properties, including a large chemically active surface area, a high cation exchange capacity and interlamellar surfaces having unsual hydration characteristics. The type of exchangeable ion Na, Ca and/or Mg has a major influence on industrial and chemical uses of montmorillonite because of their hydration characteristcs. Natural occurrences of Na montmorillonite in commercial quantities are geographically limited, but Ca-Mg montmorillonite deposits are known world wide. Foundry, well drilling, pelletizing and civil engineering constitute the major uses of montmorillonite, but the total array of uses of montmorillonite exceeds that of any other mineral.

Jan 1, 1986

By Mike de Wit

Of the approximately 6,500 kimberlites known to date, less than 3% are diamondiferous and less than half of those are economically viable. Admittedly, this is a global figure and varies from area to area much depending on geological, logistical, and political circumstances. The number of diamond-bearing kimberlites is an important geobarometer, and an age-frequency profile has been compiled in order to identify diamond metallogenic epochs and provinces. Four primary diamond clusters have been recognized: Siberia (332-370Ma), Kaapvaal South(114-144Ma), Kaapvaal Southwest(84-95Ma), and Slave (52-55Ma). In addition, three secondary clusters are the Kaapvaal Central (S06-S38Ma), the Man Craton (139-lS3Ma) and the Kasai Craton (120-130Ma). The Kaapvaal is the only area where kimberlites with diamonds were discovered between 1870 and 1925, except for the Prairie Creek discovery in North America in 1906 and Colossus in Zimbabwe in 1907. Between 1906 and 1940 no major diamondiferous kimberlites were discovered, but many of Africa's alluvial deposits were found and exploited in that period. Advances in scientific prospecting in the 1940's rapidly accelerated the discovery rate that peaked in the 1990's; 39 diamondiferous occurrences were found in the 1980's, of which 8 became mines and 5 are in feasibility, and nearly 450ha of kimberlite was added to the global resource base. Despite the accelerated exploration expenditure, the last decade (e.g. 2000-2009) has been the leanest since the 1940's. The most important reason for this decline in exploration success is that any undiscovered deposits are largely buried by younger cover. Understanding complex and geophysical noisy basement geology, as well as decomposition of path-finder minerals are major challenges to further exploration success. Major investments in basic geological expertise and field research will have to be made in order to secure future diamond resources. Integrated geophysical studies, geochemistry diamond forensics, and improved imaging of Earth's upper mantle are perhaps foremost in this requirement, but the costs of these activities are such that government support will be required if countries are to sustain their diamond mining industry.

Jan 1, 2010

By The Staff

This is in direct contradiction to the generally accepted philosophy of tube-mill grinding, which is based upon an enormous amount of experiment carried on in different parts of the world. Personally, I have no faith in the reliability of these conclusions of the authors. (Incidentally, the two circuits compared consist of six mills each of which the change in the hook-up is only in the last three mills-in one case, these three mills are in closed circuit and in the other, open or series circuit. Hence the last three mills are alone responsible for the alleged improvement, which means that the improvement in these three mills amounts to at least 18.8 per cent). The value of these figures depends upon the reliability of the work, of the measurements and the calculations of the authors. As very little information is contained in this Addendum concerning the methods of the work and the details of the measurements, it is necessary, in order to form an estimate of this reliability, to study carefully the previous paper published in the July, 1940, BULLETIN(3). Referring to the original paper, the present paper has this to say (bottom of page 379): "Here it may be remarked that we have made more money for Lake Shore digging into and forming the report than in obtaining the figures and data, and so far have never gone back to work on it without a resulting Lake Shore profit". Let me state that I, so far, have never gone back to work on it without finding more discrepancies and inconsistencies and illogical reasoning. In my first contribution to the discussion of the first paper, which discussion was published on page 355 and following, in the July, 1941, BULLETIN, I pointed out discrepancies and inconsistencies and illogical reasoning.

Jan 1, 1942

By CHARLES R. KETES

I. INTRODUCTORY. INDUSTRIALLY, the most important service that geological science can now render to mining in the Upper Mississippi leadand zinc-fields is to devise some practical scheme whereby the productive ore-belts may be located with greater certainty than they have been in the past. Up to the present time there has been little service of this kind, and in spite of all that has been worked out concerning the geologic features of the region, and notwithstanding all that has been written about these ore-deposits, this particular phase of the subject has been, for some reason or other, the very one that has received the least consideration. The neglect by geologists in this respect has been all but complete. The following notes are suggestive of some practical solutions to the problems presented. As here suggested, the geologic relationships of the ore-bodies were surmised some years ago, though somewhat vaguely perhaps. No opportunity for securing critical data appeared until recent investigations of a private character were undertaken, which bad in view the extensive prospecting of undeveloped areas. Fresh from rather wide experiences of a decade in the principal mining-regions of four continents, and after a lenstrum's residence among the chief mining-camps of the West and of Mexico, under conditions which measured geologic hypotheses in meters and rigidly tested their values in, terms of dollars, the recent return to the Joplin field and a new survey of its ore-conditions were fraught with somewhat unexpected results. Aspects of the ore-deposition were presented of which previously there was no hint. Ten years' absence from the district had tended greatly to clarify former hazy impressions. It enabled many features, then only dimly outlined, to be considered more nearly in their true perspective and in their real relationships to their surroundings. It permitted a great mass of details collected a dozen years before in connection with the work of the Missouri Geological Survey to be viewed under new light and to

Feb 1, 1909

By W. M. Goodwin

"IntroductionIN THE preceding paper we have learned about Canada's resources of metallurgical coal. There is an adequate amount in Nova Scotia, a very large reserve on the eastern flank of the Rocky mountains, and a strictly limited supply on the Pacific coast. Added to these is an unknown quantity of coking coal in the Peace River district, at present rather isolated but possibly capable of industrial development in the future.The chief use of metallurgical coal is to make iron and steel. For this, an adequate supply of iron ore is required. So we should now scan the Canadian supply of iron ore, the possibility of its increasing use at home, and the probable markets abroad.Trade in iron ore tends to be international, as is the case with many other raw materials. The present tendency with iron and steel, in contrast, is to keep its manufacture within national boundaries, and there is no evidence that this will change much in the years to come. We should keep these two points clearly in mind when considering the disposal of iron ore from Canadian mines. We should remember, also, that the modern blast furnace and steel plant has such a large output that a correspondingly large population, reasonably compact, is needed to consume its products.Large Ore Supply in East, Small in WestCanada has now four major iron ore fields, well situated to serve adequately the eastern half of the country. Wabana .and Labrador are well placed to serve overseas markets and plants on the eastern seaboard and eastern interior of the United States and Canada."

Jan 1, 1952

By Robert D. Irvine

"Enhanced concern for protection of the environment and attendant actions by environ-mental regulatory authorities in support of this concern are influencing, to varying degrees, the demand and supply of a range of industrial minerals in a number of jurisdictions. These influences take a variety of forms.In this paper, the author seeks to delineate certain broad trends which are occurring relative to industrial minerals and the environment and then, through a series of examples, to outline opportunities, developments, and impacts respecting a number of industrial minerals produced and consumed in Canada and the United States."

Jan 1, 1996

By Robert W. Ageton

The Bureau of Mines investigated the in situ vertical component of the rock stress in the rib of the haulage drift on the 6100-level of the Star mine, Burke, Idaho, using the flatjack and borehole deformation methods. The estimate of the vertical component of stress about 2 feet into the rib at a station along the haulage drift on the 6100-level of the Star mine by the flatjack method is approximately 5,875 psi, whereas the borehole deformation procedure at this station yielded a value of 5,500 psi for the same depth into the rib. The test zone is approximately 5,625 feet below the surface.No attempt was made to extrapolate stress estimates beyond the depth of the flatjack installation.

Jan 1, 1967

By MINE SAFETY BOARD

Mining men and State officials in their efforts to make mining safer are confronted from time to time with various complicated questions . In recent years these questions have tended to increase with the use of mechanical appliances . Twenty- five years ago electricity had hardly been used in mines . To - day there is practically no other means of transmitting energy employed in American mines , except in metal mines where compressed air is used for drilling and small portable hoists . In coal mines there has been a great increase in mechanization and a tendency to concentrate the mining operation , which has resulted in attendant difficulties of ventilation and intensified the danger of coal - dust in bituminous and subbituminous mines . The answers to the questions which arise are not always obvious , as is shown by the fact that even able , experienced men differ in their opinions of the best way to overcome a particular mining hazard . The difficulty of solving the problems is also demonstrated by the varying provisions in mine safety rules , both in official regulations and in the rules of those mining companies who are endeavoring to do more than follow the letter of the law . Such differences of opinion on the best way of meeting a difficult situation are often found within the same mining organization , and so it has been in the Bureau of Mines .

Nov 1, 1929

By R. J. Hundhausen

This report describes the exploration and recent utilization studies the Bureau of Mines conducted on the Iron King, Chambers, and Dry Camp chromite deposits in the John Day district, Grant County, Oreg. The field investigations were undertaken during parts of 1939 and 1942 to determine the tonnage and grade of chromite in the district that could be utilized as a war reserve for the steel industry. As a result of the Bureau's field work, which included construction of 9 miles of access road, 6,204 feet of diamond drilling, 195 channel samples, and 1,020 linear feet of trenching, an ore reserve of 208,000 tons of 22-percent chromic oxide was indicated in the 3 deposits. Less than 1,000 tons of this ore has been mined since the field work was completed because the 2 largest deposits are submarginal in grade and there is as yet no incentive to develop and mine the ore. Since the war, however, the Bureau has been seeking means of utilizing the ore. Two methods of utilization that show promise are direct smelting of the ore in an electric furnace and use of the chromite for making refractory brick.

Jan 1, 1956

By Charles T. Holland

INTRODUCTION Insofar as I am aware, the term rock mechanics was not in the English dictionary in 1930 when I started my graduate program at West Virginia University. Hence, I never thought that I was undertaking studies in rock mechanics when I undertook to write a thesis on the physical properties of West Virginia coal. In this case, the subject was primarily concerned with the compressive strength of coal, the elasticity of the coal, the physical weathering properties of the coal and its friability. These days investigations of rocks pertaining to such properties are included in the term "rock mechanics". Other than this aspect, the principle interest in this part of my program was that I became interested in the strength of coal from the standpoint of structural purposes, and also became cognizant of its elastic properties as well as its energy storing properties. This research also tied in with a remark that Professor Lawall made in a Mining Methods class in 1928 when he remarked that a peculiar thing was happening in the southern part of West Virginia, namely, in the Pocahontas coal field. His remarks were to the effect that pillars were blowing up in the mines and when asked why he replied the cause was not known. The failure of three-inch coal specimens, especially those in stronger coal, in non-hydraulic actuated testing machines was reminiscent of his description of those pillar bursts or bumps.

Jan 1, 1971

By W. P. Diamond, J. R. Levine

The explosion hazard of methane-air mixtures has become an increasingly serious mine planning problem, and an advance assessment of methane gas potential can therefore be essential for a safe and economic mine development pro- gram. As part of its coal mine health and safety program, the Bureau of Mines has developed a simple, inexpensive test to measure the methane content of coal samples obtained from exploration cores. The gas content of coal per unit weight as determined by the direct method test can be used as a basis for a preliminary estimate of mine ventilation requirements, and to determine if degasification of the coalbed in advance of mining should be considered. Since the Bureau began measuring the gas content of coal samples in 1972, experience has led to equipment and procedural changes, the most significant of which has been the development of a ball mill for crushing the coal sample to release the residual gas at the end of the desorption test period. This revised procedure replaces the crushing box and graphical methods described in earlier Bureau publications. The results of 583 direct method tests are summarized in tabular form. These results include data on the gas content of 125 coalbeds in 15 States.

Jan 1, 1980