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By Alton Gabriel

During the fall of 1940, J. R. Thoenen of the Mining Division, Bureau of Mines, accompanied by the senior author, surveyed the more important domestic alunite deposits. Although the study was designed primarily as an economic survey, samples from a number of the deposits were collected to investigate the beneficiation of the lower-grade material.

Jan 1, 1942

By Alton Gabriel

During the fall of 1940, J. R. Thoenen of the Mining Division, Bureau of Mines, accompanied by the senior author, surveyed the more important domestic alunite deposits. Although the study was designed primarily as an economic survey, samples from a number of the deposits were collected to investigate the beneficiation of the lower-grade material.

Jan 1, 1942

By Tom Barry, Kameron Ray, Dr. Gavin Yuill

Imerys Talc, Yellowstone Mine in Montana faces significant geotechnical challenges such as poor wall quality and local instabilities. These instabilities are driven primarily by the characteristics of the rock mass, but are aggravated by drilling and blasting operations.

Jan 1, 2016

By Thomas S. Jones

This report discusses processing and use of the principal forms of manganese. The focus is on trends in the United States in the 20th century and specifics of domestic manganese material flows as of about 1990. To protect proprietary data, quantitative assessments are limited to the iron and steel industry, which accounts for about 90% of consumption. Nonmetallurgical uses are considered qualitatively. Approximate disposition of a U.S. cumulative consumption during 1901-90 of an estimated 69 million st of manganese is estimated to be iron and steel slag, 69%; nonmetallurgical uses of a dissipative na¬ture, 10%; iron and steel scrap, 9%; National Defense Stockpile, 3%; unidentified and/or including items in service, 10%. In slag from iron blast furnaces and steelmaking, manganese is present as a minor, relatively im¬mobile component, which so far has been uneconomical to recover. Construction and road building are main applications for these slags. Steel slag contains the greater amount of manganese. Studies by others of global manganese fluxes and the effect of human activities on them also are discussed. One source concludes that the main effect of human activities, via deforestation and agricultural activities, has been to increase the rate of transport of manganese to the oceans.

Jan 1, 1994

This summary of State laws or explosives was compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful In determining whether relevant statutes exist, and In locating them quickly,-with a minimum of effort. It will be of value also in comparing statutes in one State with similar statutes in other States to determine what construction has been placed upon them by the courts of those jurisdictions or to contrast the varying provisions of many States upon a similar subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although this sometimes has resulted in disruption of the continuity of individual acts, the increased general clarity and availability of comparable sections have more than justified the procedure followed.

Jan 1, 1943

By Conné Spangenberg

Contents ?Introduction ?Metal accounting environment ?Problem statement ?Investigations & Achievements ?Metal Accounting ?Principles ?Standards ?Audits ?Questions

Jan 1, 2005

By Yves St-Amour, Vince Luongo

This paper will discuss one of the largest construction projects the City of Portland has undertaken. This phase of the Willamette River Combined Sewer Overflow (CSO)project consists of approximately 18,500 ft of tunnel in soft ground, requiring the construction of six deep shafts and jet grout ground improvement. The purpose of the project is to reduce volume of combined sewerage overflows from the drainage areas on the west side of the Willamette River. Bencor-Petrifond-Pacchiosi Joint Venture was awarded a contract to design and construct six deep circular shafts, jet grout ground improvement for three bridges and jet grout ground improvement break-in/outs for some shafts. Of the six shafts the Pumping Station Shaft was the deepest and largest, requiring a permanent ground support system with a deep jet grout ground water cut-off to 335-ft deep. The joint venture used state of the art methods and equipment to achieve its objectives and build the structures through some very difficult alluvial soils to great depths next to the Willamette River. The paper will provide a general discussion of the shaft construction and jet grout ground improvement installed for this phase of the project. It will also discuss some of the technical challenges encountered while effectively managing risk and costs, resulting in a successful project completed in a timely manner.

Jan 1, 2005

Case 1: A driller raised a drill rig mast into a 7200-volt overhead power line. Both he and his helper were killed. Case 2: A driller-helper was pulling a winch cable toward a stack of drill steel when the cable contacted a 12,000-volt power line. The helper was killed, and the driller at the rig controls was severely injured. [ ]

Jan 1, 2006

By E. Adam, B. Milkereit, M. Salisbury, L. E. Reed, G. Perron

Integrating seismic reflection, borehole geophysical, and physical rock property studies is an effective means of mapping lithological contacts and structures in the crystalline crust. At Les Mines Selbaie in the northern volcanic zone of the Late Archean Abitibi Subprovince, a high-frequency seismic reflection profile has provided the first images of deep crustal structures of this important polymetallic mine site. Physical rock property and borehole geophysical studies confirm that prominent seismic reflections can be caused by lithological contacts, faults and sulphide mineralization. At Les Mines Selbaie, the first two of these are shown by this study. Clearly identifiable reflection images from sulphide mineralization have not been demonstrated in analysis of the profile. The seismic images provide useful information about gross structure in the vicinity of Les Mines Selbaie. They can also place important constraints on the sequence of tectonic events and, therefore, can aid future deep exploration programs.

Jan 1, 1997

This publication is designed to be helpful in promoting health and safety in tunneling and related operations. The format has been selected and arranged to provide a condensed guide for safety personnel, inspection and investigative agencies, design and project engineers, and others responsible for the health and safety of workmen. All the precautionary measures recommended are based on actual conditions observed, from investigations of fatal or serious accidents, and from research conducted to find ways and means of alleviating hazards and unhealthful conditions. Many of the recommended rules are included in State laws and in the general safety requirements of the construction industry. Explanatory, descriptive, and qualifying information has been largely omitted in this publication to keep basic data in more useful and compact form. Included in the appendixes are special precautions for gassy (methane atmospheres) tunnels and tunnels where petroleum products are encountered.

Jan 1, 1968

By J. Mason

In order that the use of continuous mining machines be most economic, the equipment must be operated at rated capacity as much of the time as possible and downtime for repairs kept at a minimum. A large factor influencing any proposals for maintenance programs is the complexity of the machines—often the intricacies of the precision-built equipment requires engineering knowledge byond the scope of mine maintenance personnel. A training program is part of the answer; there are others. In addition to investigating a joint company-manufacturer equipment-design improvement program, Mountaineer Coal Co. has launched a detailed preventive maintenance program to combat extensive downtime often encountered when continuous miners are used. Everyone in the coal industry knows the importance of operating continuous miners at their rated capacity as much of the time as possible. The potential capacity of the miner is such that l-min. delay means from 3 to 8 tons of coal lost. Today's miner is a well designed, precision-built machine, complicated with hydraulic and electrical equipment and complex mechanical assemblies with all possible combinations of gears, levers, and rods. As the machine becomes more complex, the problem of maintenance becomes more acute. The transition from conventional to continuous mining has taken place so rapidly that the mine mechanic has been unable to keep pace. When there is a machine failure, the maintenance man usually employs either the trial-and-error or the play -it-by-ear method of repair, but this represents an expensive proposition. Mine mechanics, maintenance superintendents, and mine managers complain about the complexity of the machines and how difficult it is to keep them running. There is no shortage of skill in the design offices. Machines are designed by good engineers, but for engineers. What's the answer? Better trained maintenance men—better maintenance instruction—better field service. These are all good corrective measures, but the real cure is to provide for the men at the do it level. Designers have got to cooperate with men to simplify maintenance on the increasingly complex machine. The designer must be aware of how his machine can be maintained. Sometimes a simple design change in a bearing, oil seal, or a bushing will correct recurrent breakdowns. Parts such as filters, hydraulic cylinders, hoses, and pivot pins can be better arranged on the machine to make them accessible so that the mine mechanic can easily keep the machine producing. Therefore, to get our maintenance off on the right foot, the program must begin back in the design office, before the machine is delivered to the mine property. Realizing the importance of this aspect, our company set out on a joint company-manufacturer equipment-design improvement program. This is a formal program in which quarterly reports are written covering machine defects, design weakness, and general problems relating to machine maintenance and performance. The manufacturer in turn comments on each and every item appearing in these reports, indicating the action he proposes to take. In addition to the written reply, meetings are scheduled with manufacturer representatives to discuss further the outlined problems. The benefits realized from this organized program are both substantial and far reaching. Good maintenance begins with a good design. The subject of preventive maintenance is not a new one. Volumes have already been written on the subject. It consists primarily of doing the maintenance work when you want to rather than when the machine demands it. However, a preventive maintenance program can be overdone. Theoretically, if carried to ridiculous extreme, all working time could be spent inspecting and repairing the machines and no time would be left for production output. Our goal in maintenance is to maximize running time for all machines, and to prevent or at least minimize production downtime. INSPECTION AND REPORTING The center of any preventive maintenance schedule is regular and systematic inspection, but it must be

Jan 1, 1961

Kudremukh Iron Ore Company Ltd, a wholly owned Government of India Enterprise, was established in the year 1976 to develop mine and plant facilities to produce 7.5 Mtpa of high-grade iron ore concentrate at Kudremukh. The mine and plant facilities were commissioned in 1980. In view of high demand for iron oxide pellets in iron and steel industry worldwide and as a diversification activity, a pelletisation plant of 3.0 Mtpa capacity was commissioned in the year 1987 at Mangalore for production of high-quality blast furnace and direct reduction grade pellets for export. The pellet plant capacity has been increased to 3.5 Mtpa by technological improvement which included installation of roll press for quality and productivity improvement. In addition, the pellet capacity is being increased to 4 Mtpa by the addition of Shaft Pelletising Furnace plant.

Jan 1, 1999

Laboratory scale equipment was developed to recover zinc as oxide fume from granulated lead blast furnace slag. The cyclone furnace process is characterised by high treatment rates combined with continuous and independent operation.Results were sufficiently encouraging to warrant pilot plant scale trials being undertaken.INTRODUCTIONSince granulation of lead blast furnace slag started at Port Pirie in 1921 the stockpile of this material has increased to nearly 5 million tons which averages 17·5 per cent zinc by weight. Although a number of processes for recovering the zinc have been examined, economic considerations indicate that a slag fuming process is likely to be most suitable.In the conventional slag fuming process zinc is extracted by injecting pulverized coal and air into a molten slag bath. By maintaining a suitable air to coal ratio the oxidised zinc contained in the slag is reduced to metal. Volatilization of the zinc is followed by reoxidation in the gaseous phase with the addition of further air above the bath. The zinc oxide fume so produced is collected by normal gas cleaning methods.By examination of the thermodynamics of this process Bell, Turner, and Peters (1955) determined the zinc oxide activity of the slag over the duration of the fuming cycle.A combination of high temperature and high carbon monoxide/carbon dioxide ratio was found necessary for rapid zinc elimination.Since melting of the slag is an essential step in the slag fuming process, only two treatment methods appeared possible at Port Pirie until recently...

Jan 1, 1964

By Julian Malnic

Transplanting the steps used in exploring and developing mineral deposits on land into the marine environment will help developers. While familiar to oil and gas explorers and many other sea-based industries, the marine environment is so alien to the 90s terrestrial miner that the phrase ?terrestrial mines in the sea? is useful for reinforcing the fundamental parallels in mining sulphides at sea and on land. As on land, the processes of ?pre-feasibility study? and ?feasibility study? will determine the economics of mining a deposit. For many, the step into the sea can detract from the need to follow these familiar and recognised steps used when any new deposit is found on land. The technology to mine sulphides in the 1500 to 2000 m depth range exists. Currently, it is not found in a single, integrated and commercially available system but every element available to build such as system is. Transplanting the thinking of the leaders of the terrestrial mining industry into the sea will perhaps be the greatest challenge and reinforcing the basic steps of discovery - pre-feasibility through to feasibility is the best way to achieve this. After all on land one doesn?t ask ?Can we profitably mine it?? before one can authoritatively answer ?What have we found??. Research by Nautilus Minerals Corporation suggests that the mining of seafloor massive sulphides (SMS) will not only be profitable but potentially lower in both capital and operating costs than prevail in most terrestrial deposits. Nautilus is also acutely aware that with the first SMS deposits under title, it will be setting the standards for seafloor mining into the new millenium. Indeed, we have trained on us not only the eyes of the mining industry waiting to see if SMS deposits really do offer radically better returns, but other stakeholders of the sea and the capital markets. Mistakes by any SMS developer could land all developers in ?hot water?. The rush to exploit our deposits for economic gain will be tempered by ensuring there is adequate public debate and consultation for our environmental code. Failure in any facet of a marine mining development could set back the move to the ocean floor.

Jan 1, 1998

By M. W. Franklin, D. W. Hendriks

"Changing ore types, feed grades and c1rculat1ng loads are some of the many factors that can make flotation feed-back control difficult. To control a flotation circuit using conventional fixed-parameter control algorithms, one must either tune the controllers very often or tune the controllers to the middle of the normal operating range. The former approach is very time consuming, while the latter approach can lead to long periods of either very sluggish responses or highly reactive responses which can lead to instability. The problem becomes compounded if feed-forward variables are introduced, creating even more variables to tune. An alternative to a fixed-parameter control algorithm is an adaptive control algorithm. An adaptive control algorithm continuously retunes itself based on previous reactions to its changes. Feed-forward control also becomes much more viable because the algorithm will tune the feed-forward parameters and the feed-back parameters simultaneously. Using the combination of feed-forward and feed-back tuning is an effective way to decouple the loops needed in flotation circuits where one circuit feeds into another. The advantages of adaptive controllers over conventional controllers will be introduced through the use of a simulator. Also discussed will the be the implementation of adaptive controllers at Brunswick Mining and some of the modifications that are available to help solve more difficult control problems.Brunswick Mining is located just outside of Bathurst, New Brunswick. The concentrator processes approximately 10250 tonnes per day of ore that assays at approximately 8.9 %zn, 3.6 %Pb, 0.3 r.cu and I 00 gram/tonne of Ag. The four products produced are zinc concentrate assaying 51 %Zn, lead concentrate assaying 34 %Pb, copper concentrate assaying 21 %Cu, and a bulk concentrate assaying 32 %Zn and 18 %Pb."

Jan 1, 1986

By Robert L. Lagace

A prototype adaptive volume control for the loudspeaker output of mine trolley carrier phones was designed, built, and tested in the laboratory and in a mine. This volume control senses, and adapts to, the ambient acoustic noise environment in such a way as to produce a loud sound output under noisy conditions, and a quieter output under quiet conditions, thereby producing an understandable and unstartling volume level under all noise conditions. The design approach, prototype hardware, and test results are described, and the device is shown to be feasible for in-mine operations. The circuit design principles are easily applicable to currently available mina trolley carrier phones. Recommendations for practical improvements are included. An in-mine experiment to assess the practical feasibility and utility of the dedicated wire technique for overcoming poor trolley carrier phone system performance was designed, performed, and evaluated. The technique involves the use of a single, low-loss, properly terminated auxiliary wire, placed in the rail haulageway, which allows signals to naturally couple to and from the trolley wire/rail transmission line, and thereby significantly decrease the overall signal attenuation rate on the trolley wire/rail line. The in-mine dedicated wire experiment, results, and conclusions are described, and the technique is shown to be a valid and practical one for significantly Improving carrier phone system performance in mines. Guidelines for the installation and use of the dedicated wire are provided. Recommendations are made for obtaining further practical information on its performance and utility. A second in-mine experiment to assess the feasibility and utility of the low-impedance (low-Z) line technique for overcoming poor carrier phone signal transmission in mines was designed, performed and evaluated. The low-Z line technique involves the periodic connection of shunt capacitors between the trolley wire and the rail to artificially lower the line characteristic impedance. This causes the low impedance shunt loads encountered across the trolley wire/rail line to be less mismatched to the line, thereby reducing the overall attenuation of carrier phone signals. The results of in-mine experiments performed along unenergized and fully operational sections of trolley wire/rail line are described. The experiments were designed to measure line parameter such as inductance and capacitance per unit length, characteristic impedance, and propagation phase velocity, in addition to signal strength versus distance behavior under normal and low-Z line conditions. The low-Z line technique is shown to be valid, but not as practical as the dedicated wire technique which is recommended as the most favorable for most coal mine applications.

Jan 1, 1979

Recent literature is reviewed with emphasis on the design and scale up of mixers. Most important aspects of mixing have resulted from the study of Newtonian fluids and only a minor attempt has been made to extend the work to non-Newtonian materials.The rheology of non-Newtonian materials is outlined and the typical behaviour of mineral slurries is indicated.The importance of flow velocity, flow pattern, and fluid turbulence is discussed with relation to suspension of solids and rate of reaction.Data on experimental leaching of ore from Mary Kathleen, Queensland, show the effect of different mixing impellers.In conclusion, factors involved in the selection of a mixer are presented with emphasis on economic appraisal after pilot experimentation.INTRODUCTIONThe subject of mixing has attracted considerable attention during recent years, but relatively little work has been undertaken for the study of non-Newtonian materials. Most work has been restricted to Newtonian fluids because there are less inconsistencies in such study.Mixing, by definition, implies blending or combining, and ranges from gentle mixing which blends the contents of a large tank in 24 hours to violent mixing which completely homogenises the contents of a tank within seconds. Metzner and Otto (1957) have pointed out the present lack of knowledge on the degree (or quality) of mixing. Apart from this fact the design of mixers for Newtonian materials would seem to be reasonably certain.Both capital and operating costs rise rapidly with increasing mixer size. Therefore the design, or selection, of a mixer is a matter for economic consideration in the overall aspect of plant design and operation.

Jan 1, 1961

By J. Kretschmann

Mining heritage can be of outstanding value for many regions around the world, because mining has been done for thousands of years for the benefit of mankind and its development. This paper presents an ongoing project creating a general guideline for the handling of mining heritage on the basis of experiences made in Germany. Interactions of stakeholders in the ?heritage network? as well as strategies for the technical proceeding will be described. An action plan for the sustainable handling of mining heritage has already been developed in part, which includes necessary measures. Best-practice recommendations will be derived. Keywords: m ining heritage / preservation / guidelines / action plan / Sustainability

Feb 27, 2013

By Y. Sasseville

"Niobec has been using vibrating screens and screw classifiers as a double stage classification in its grinding circuit since the very beginning of its operation in St-Honoré. Most of the other mineral processing plants around the world uses cyclones as the classification device in their grinding circuit. The difference between these two methods are well known in terms of capital cost and grinding efficiency but the differences in terms of the impact on the downstream processing stages are a lot harder to predict and are case specific. In the interest of lowering the capital cost of a future expansion project, Niobec decided to test the cyclones in its actual grinding circuit and evaluate their impact on the recovery of the downstream processing stages as well as the operating cost of the mill. We switched between cyclones and screens for 8 month in 2013 and early 2014 and we are now operating only with cyclones since march 2014.INTRODUCTIONThe Niobec mine and concentrator were built in the mid 70’s and at that time, the mill was processing 1 500 tons per day. Over the years, many expansion projects have brought the plant to 7 000 tons per day. Throughout the initial concentrator design and commissioning, screens have been chosen over cyclones because of their higher classification efficiency which is known to reduce variability and limit the fine generation especially due to a high undersize classification efficiency. Just like many other plants, fine particle generation is a major problem at Niobec because of its negative effect on downstream processing stages. In the interest of lowering the capital cost of a future expansion project, Niobec’s engineering team decided, 35 years later, to test the cyclones in its actual grinding circuit and evaluate their actual impact on the final recovery and the operating cost of the mill.The grinding circuit is separated in two lines which will be called Circuit #1 and Circuit #2 along this paper. Circuit #1 is, as you can see in Figure 1, composed of a rod mill and two parallel ball mills in closed circuit with screens and screw classifiers. The screens oversize are sent to the screw classifiers while the undersize are sent to the next processing stage. The screw classifiers overflow are both sent back to the pump box while their oversize streams return in their corresponding ball mills for further grinding. Circuit #2 is, as you can see in Figure 1, quite the same as Circuit #1 except it has only one set of screw classifier and ball mill. Figure 1 also shows the modification in arrangement each circuits went through to integrate the new cyclones. One of the ball mills in Circuit #1 now appears dotted because it can still be used but is not now"

Jan 1, 2015

By Clarke DS

The igneous intrusions in SE Papua New Guinea are part of a sub-volcanic to plutonic, high-K calc-alkaline to shoshonitic suite. High-K andesitic to dacitic intrusives on Misima and Woodlark Islands, and shoshonitic intrusives in Milne Bay and the eastern Owen Stanley Ranges are related to late Cenozoic andesitic volcanism. Both suites are associated with epithermal Au-Ag deposits and weak porphyry Cu-Au mineralisation. All significant alluvial and lode gold occurrences in the region are spatially related to intrusions. Intrusions in the D'Entrecasteaux Islands and near Mt Suckling are core plutons related to basement doming, and appear to have no association with either volcanism or hydrothermal mineralisation. The core plutons are not petrochemi:ally distinct from the volcano-re:-ed Intrusions.

Jan 1, 1991