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By M. B. Wechsler

An analysis is developed for determining the maximum loading, as well as the potential uplift of the piles on bridge pier foundations. There are considered piers supported on two through seven rows of piles, and related to two simply supported collinear superstructures of any structural material. The study leads to different types of influence lines for various load combinations. For load combinations containing vertical loads only, the related influence lines are similar to those as for the bending moments of a virtual span covering the two actual spans, as well as the gap between the two superstructures; and, in this case, the heavier loads should be positioned in the vicinity of the pier. While, in the case when vertical loads are acting together with hori­zontal forces, the related influence lines will indicate where the heavier live loads should be positioned. And they will also indicate on which portions of the spans the live load should be avoided.

Jan 1, 1989

By Stephan Stecura

Crystallographic modifications and kinetics of solid-state phase trans-formations were determined for five rare-earth" sesquioxides--La2O3, Nd2O3, Sm2O3, Eu2O3, and Gd2O3. Oxides used for crystal modification studies were prepared by thermal decomposition of the following high-purity salts of the five rare-earth elements--carbonates, chlorides, fluorides, nitrates, oxalates, and sulfates. X-ray diffraction patterns of the cubic and hexagonal oxides were indexed by a graphical method and patterns of the monoclinic oxides by Ito's method. The kinetics of crystallographic transformation were determined by high-temperature X-ray diffractometry. The kinetic data were interpreted using a shrinking sphere model. All of the transformations followed first order kinetics. Activation energies were calculated by application of the Arrhenius equation. These solid-state phase inversions were concluded to occur by a reconstructive transformation mechanism.

Jan 1, 1965

By Michael J. Brown

It is often necessary to undertake some form of pile testing to verify design calculations. Historically this has been limited to static and dynamic tests. Newer rapid testing methods such as Statnamic are seeing more frequent use. This form of testing can be advantageous due to short set up time and test duration. Although the methodology suffers from a lack of formalised guidance and may prove difficult to analyse in certain soil conditions. This paper investigates the suitability of Statnamic testing and analysis for a range of soil and pile types as well as different installation methods through a number of case studies undertaken in the UK. Recommendations are made on test specification and analysis.

Jan 1, 2006

By T. H. Jeffers

Significant amounts of cobalt are present in readily accessible spent copper leach solutions. The Bureau of Mines investigated the feasibility of extracting cobalt from these solutions in a multiple-compartment ion-exchange (MCIX) column. The effects of aqueous flow rate, resin flow rate, column height, and compartment height on cobalt extraction were determined. Cobalt extractions of 92 pct or higher were achieved at solution flow rates of up to 5.5 gpm/ft of column cross-sectional area and an aqueous-to-resin flow ratio of 40:1. Overall cobalt extraction increased as the column height increased, but cobalt extraction per unit of length was more efficient in 8-and 12-ftco1umns than in an 18-ft column. Solvent extraction procedures were utilized to purify and concentrate the MCIX column eluates and produce a cobalt sulfate solution containing 70 to 80 giL Co. Metallic cathodes containing over 99 pct Co were e1ectrowon from this solution. Zinc, nickel, and copper byproducts were also recovered during processing of the ion-exchange eluates. Estimated total capital cost for a commercial-scale 10,000 gpm of a spent leach solution containing 26 million. With credits for zinc, nickel, and copper estimated net operating cost was $9.36/lb Co.

Jan 1, 1987

By B Lumsden, B Lacouture

"Red Dog is one of the largest zinc mines in the world both in terms of reserves and annual production. In 2013, Red Dog produced 551,300 mt of contained zinc and 96,700 mt of contained lead. The mine, which is located in Northwest Alaska, is a partnership between Teck Alaska Incorporated, the operator of the mine and NANA Regional Corporation Inc, the local land owner. The Aqqaluk deposit, which is the current source of ore, has an average grade of 15.8% Zn, 4.1% Pb and 73 g/t Ag with the main minerals being sphalerite, galena, pyrite, barite and quartz. Surveys of the zinc flotation circuit at Red Dog identified that a substantial amount of fully liberated, sub 20 micron sphalerite particles were being lost to final tailings. As a means of improving fine sphalerite recovery, a four month plant trial of magnetic conditioning was conducted in the zinc retreat circuit. Magnetic conditioning technology has already been commissioned in several concentrators around the world to agglomerate fine paramagnetic minerals, increasing their probability of bubble collision and recovery in a flotation cell. The results of the four month plant trial at Red Dog showed that at a high level of confidence, a 1% increase in zinc recovery or zinc recovery and zinc concentrate grade combined was achieved with magnetic conditioning. The resulting economic benefit, which is also at a high level of confidence, is significant to Red Dog and therefore, magnetic conditioning has been permanently incorporated into the Red Dog zinc flotation circuit.IntroductionRed Dog is the largest zinc mine in North America and represents approximately 29% of North American zinc concentrate production. The mine is located in northwest Alaska, approximately 100 miles north of the Arctic Circle and 50 miles inland from the Chukchi Sea. The remote location makes the mine accessible only by air or seasonally by ocean-going barges. Red Dog is a partnership between NANA Regional Corporation Inc, the land owner and Teck Alaska Incorporated, the operator of the mine."

Jan 1, 2016

By E. R. Bauer

Prolonged exposure to noise can cause permanent damage to the auditory nerve and/or its sensory components, known as noise induced hearing loss (NIHL). It is the most common occupational disease in the United States today. The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) is addressing NIHL in the mining industry through several research efforts. This paper presents a general review of NIHL, the status of NIHL in mining, the results of the longwall noise surveys, and a review of the longwall engineering controls research efforts.

Jan 1, 2008

By R L. Chaney, M Mahoney

Mine and ore beneficiation wastes and smelter contaminated soils often cause phytotoxicity and threaten adverse environmental effects if not remediated. Science has clarified both the risks from soil metals and methods to alleviate those risks that can be applied at low cost. Phytoremediation is a family of plant and agronomy based technologies to deal with environmental aspects of sites requiring remediation. If valid risk assessment indicates that metals comprise risk, phytostabilisation may be used to alleviate that risk for most contaminated sites. In particular, Zn-Pb, Cu and Ni mine and smelter sites are readily remediated by making the soil calcareous and fertile, with added organic and metal sorbent amendments that include soil microbes to ‘revitalise’ the soil. In each case, the soil fertility and causes of phytotoxicity should be clarified by agricultural soil extractions, and the combination of amendments required to improve fertility and reverse phytotoxicity identified and found locally. In contrast with phytostabilisation, phytoextraction/phytomining uses rare metal hyperaccumulator plants and agronomic management to maximise annual phytoextraction of soil elements into plant shoots for harvest, ashing and use as a metal ore. Plants that accumulate more than two per cent Ni in shoots, and yield 10–20 t ha-1 dry biomass yield 200–400 kg Ni ha-1, which has value greater than all common agricultural crops. Considering the value of elements, existence of hyperaccumulator plants and demonstrated agronomic management for Ni phytomining, it is clear that mine sites and Ni mineralised subore-grade serpentine soils can be phytomined economically as an agricultural mining technology. A team developed agronomic methods and improved cultivars of Alyssum, which can be profitably grown on temperate zone Ni mineralised or contaminated soils. Plant species for tropical ultramafic soil materials have been identified. Phytoextraction is also strongly needed to remove Cd from rice soils to prevent human disease from soil Cd.CITATION:Chaney, R?L?and?Mahoney, M, 2014. Phytostabilisation and phytomining – principles and successes, in Proceedings Life-of-Mine 2014 , pp 3–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Dunbar D. Scott

The development in the perfection of mine-surveying instruments has been by no means rapid, as it has depended somewhat on the details of construction borrowed from astronomical and geodetic theodolites, largely on the restrictions laid down by mining companies and the prejudices of mine managers themselves, but more than all on the methods used in conducting surveys and the importance attached thereto. Mine-surveying, in some form or other, has been practiced from the very earliest times; but it has never kept pace with the other branches of surveying, or even with the art of mining itself, and cannot be recognized as an exact science until shortly before the beginning of this century. The works of Hero of Alexandria, who lived in the second century B.C., are still extant, and contain descriptions of a rectangular sighting-instrument, which he invented and called a diopter. His improvement upon this simple construction, which possibly he devised for use in the Greek mines for rough leveling-purposes and for laying out any angle, must be considered, says Hübner," as the origin of the highly perfected theodolite of to-day. Whether this instrument came into general use during the first centuries of the Christian era, is not recorded; in fact, no writer undertakes to tell how mine-surveying was conducted until 1556, in which year Agricola expounds the principles of mining and metallurgy in his De Re Metallica, devoting the entire fifth chapter to the practice of mine-surveying (see Fig. 1). In mediæval times those who possessed any knowledge of engineering skill made strenuous effort to keep their art a secret, partly on account of the miners' proverbial conservatism and partly for their own personal aggrandizement, and were, in

Jan 1, 1899

By H. Antrekowitsch

The decreasing quality of the input materials in copper recycling leads to a higher content of impurities in the anode copper. An improvement of the pyrometallurgical refining process is therefore necessary to produce high quality anodes for the copper refining electrolysis. The behaviour of the most important accompanying elements (e.g. nickel, tin, lead, zinc etc.) at different reaction conditions has to be investigated in order to improve the metal/slag reactions as well as the vaporisation by selective oxidation in the anode furnace. Therefore the thermodynamic conditions like reaction order and the activity coefficients at the copper refining process have to be known for the optimisation of this technique. Additionally the interaction between different elements has been investigated as a function of the temperature, the content of the elements and the slag composition especially for nickel. These investigations were done at the Christian Doppler Laboratory for Secondary Metallurgy of Nonferrous Metals.

Jan 1, 2005

By M. Mpofu, G. Stenzel, F. Magweregwede, B. Maphalala, T. Kgarume

Surface coal operations in which mining activities are conducted above old underground workings experience hot holes after drilling. In a coal mine, hot holes are defined as shot holes, which after being drilled have an in-hole ambient temperature of 40°C or above or show a temperature increase of 3°C or more during monitoring. Hot holes and other cavities, such as cracks, pose health and safety risks to workers, such as exposure to hot air and high concentrations of noxious gases released from these holes. In addition, workers may be exposed to premature detonation of explosives caused by in-hole temperature increases and chemical reactions. To this end, Coaltech Research Association commissioned a project to develop a Best Practice Guideline for the management of hot holes. This paper is a compilation of the activities conducted in the development of the Best Practice Guideline between 2021 and 2022. The activities included a review of standard operating procedures and hot-hole temperature-measuring and -monitoring devices, and the assessment of current hot-hole procedures at selected mines. The results indicated that management of hot holes requires a focus on pre-emptive risk assessment of mining blocks, identification of hot holes using the correct temperature-measuring devices, and continuous monitoring of hot holes from the time of drilling until just before blasting. Hot-hole management accessories, such as polyvinyl chloride sleeves, were found to be effective in insulating the hot-hole emulsion from the rock mass temperature, thus preventing the potential for premature detonation.

Sep 9, 2024

By Snehamoy Chatterjee, Dharmasai Eshwar, Aref Majdara, Rennie Kaunda, HUGH MILLER

The U.S. mining industry has made progress in reducing accidents and injuries, but interpreting safety data remains difficult due to changes in workforce size and productivity. The Mine Safety and Health Administration (MSHA) uses tools like the pattern of violation (POV) and significant & substantial (S&S) calculator to monitor safety, though these have limitations. To address this, we developed an information entropybased risk (IER) index that combines various safety metrics, including citations, penalties and injuries. Using data from 2011 to 2020, the IER index was validated with statistical methods and clustering algorithms to ensure it accurately reflects risk levels. The analysis showed clear differences in risk across mining sites, proving the index’s usefulness. The IER index was then applied to a coal mine to demonstrate its effectiveness. This new tool can help mining companies better assess their safety risks and take action to improve workplace safety.

Nov 1, 2024

By T. Binnert Haites

INTRODUCTION NUMEROUS examples of troubled zones, interfering with the normal development of coal seams, have been cited in the literature. From a geological point of view they can be subdivided into structural and sedimentary troubles. Of the latter type, wash-outs are usually the most bothersome. Some years ago, A. A. Thiadens and the author arrived at the conclusion that they represent fossil river-beds. A method of predicting the course of these rivers was developed, which has been successfully applied in the Netherlands coal measures, and more recently by P. Stassen in some of the Belgian coalfields and by the author in the Sydney coalfield. The Sydney coalfield has long .drawn the attention of geologists, and three main periods of systematic geological research may be distinguished. The first period, 1872-1900, is covered by the studies of Ch. Robb and H. Fletcher (32, 10-13) (1). Their detailed sections of the cliffs have lost nothing in value, and are frequently consulted today.

Jan 1, 1951

By K. C. Armstrong, A. B. Cron, L. A. Melis

"The Johnny Mountain gold mine in northern British Columbia, owned by skyline Gold Corporation, has been in operation since August 1988. Mill operating difficulties at the start of the operation resulted in a depleted cash flow situation and quick improvements were required to generate a self-sustaining financial basis of operation. In October 1988, Melis Engineering Ltd. was contracted to identify metallurgical difficulties, implement necessary modifications, and undertake mill operations and personnel training in order to achieve production targets.This paper presents the operating difficulties which existed at start-up and describes the methodology used to overcome production problems. Metallurgical testing results are described along with the modifications made to the milling circuit to suit ore metallurgy. Plant changes led to the operation of a simple gravity/flotation circuit to recover gold as bullion and in a copper concentrate. Operation of the originally installed cyanidation circuit was discontinued. This contributed to substantial savings in operating costs and virtually eliminated environmental problems. PROPERRTY LOCATION ANR DESCRIPTIONThe Johnny Mountain mine site is located in northern British Columbia along the Iskuit River about 60 km east of Wrangell, Alaska and 275 km north of Terrace, B. C.. A location map is presented in Figure 1 and a site plan is shown in Figure 2. The complex is located on a mountain plateau about 3, 600 feet above sea level. The plateau is flanked to the north by Johnny Mountain and surrounded on the other sides by steep cliffs."

Jan 1, 1990

By Colin M. Sargent

THE electron diffraction pattern as seen in the electron microscope represents an approximately plane section of the reciprocal lattice. Identifying the zone axis of a diffraction pattern is often laborious for a crystal of low symmetry, especially if several crystal orientations are present. A program has been written in FORTRAN II (Version 2) for the IBM 1620 which will assist in plotting out reciprocal lattice sections. The calculation is performed by choosing a zone axis [uvw] and determining the d spacings and angle between the planes (Ow - v) and (wO - u). (This procedure is varied slightly for zone axes with Miller indices equal to zero.) Cartesian coordinates for the reciprocal lattice points are then calculated for these planes and for (ww— [u + v]). Any reciprocal lattice points within the parallelogram formed by the origin and these three points are then computed. The input and output are best described by use of an example (Monoclinic ZrO2) used in the author's work. Input consists of two cards: 1) The crystal parameters: a, b, c, a, 8, y, e.g., 5.1477, 5.2030, 5.3156, 90.000, 99.380, 90.000. 2) Three numbers, D, E, F, e.g., 5, 3, 3.0710-the first is the limit of the sum (u + v + w) considered; the second limits the absolute value of u, v, and w to (E- 1), e.g., 2, so that zones (221) would be the highest order considered in this example; the third, F, is the required constant, yL. Output is in the format shown in Table I. The reciprocal lattice sections may then be plotted on standard graph paper and compared with the unknown diffraction pattern. (Note that no attempt has been made to deal with systematically absent reflections.) A card deck for the program is available from Colin M. Sargent, ARZ, W-PAFB, Dayton, Ohio, 45433.

Jan 1, 1969

By Robert Hivick, Frank Sames

The control of environmental effects, especially blast vibration and airblast, has become a dominating planning criterion for most surface blasting operations. Compliance with existing regulations is generally achieved through constraints in the blast design, or monitoring programs. Commonly, blast vibration and airblast signals are rated and compared by their maximum amplitude and the associated principal frequency. However, this data reduction limits the interpretation of the influence of varying blast design parameters on the vibration and airblast.

Jan 1, 1999

By Paul Wellman

A computer program is presented that may be used to calculate the bare equipment cost of the major processing units for any hot potassium carbonate gas purification system. The program is designed such that, with only minor modifications, it could be used with a variety of computer systems.

Jan 1, 1968

By Chu E. Ho

Current methods of determining jet grout column diameters are highly empirical and site specific, and do not take into account the jet hydrodynamics and soil parameters explicitly. A theoretical model which describes the jet excavation mechanism is introduced in this paper, with the aim of providing an improved prediction tool that can be used in jetting design. The model is based on the assumption that the velocity distribution in the cutting jet is equivalent to that of a free jet with boundaries corresponding to the dimensions of the cavity excavated in the ground. The shape of the cavity formed depends on the erosional properties of the soil and jet expansion is limited by the resistance at the jet-soil interface. The model predicts that the limit of jet penetration is reached when the average dynamic pressure at the jet tip becomes equal to the ultimate soil bearing resistance. The reliability of the model, evaluated using results from four case histories of jet grouting field trials, is within ±15%.

Jan 1, 2006

The mineralogical composition of the ore was determined and the mineral phases with which nickel is associated were identified. The ore was prepared by grinding to -420 micrometres and classification into granulometric fractions. Prior to the main series of experiments the effect of agitation rate on nickel recovery was investigated. The influence of sulphuric acid concentration, temperature and particle size on the kinetics of nickel extraction was then studied, both quantitatively and qualitatively, over fixed value intervals. Application of the initial rate method enabled determination both of the order of reaction with respect to sulphuric acid concentration and the activation energy for the dissolution of nickel. The results indicate that a physical mechanism can be ruled out as the rate-determining step in the extraction of nickel from the ore and that a chemical mechanism is more likely

Dec 1, 1991

By V. H. Whihelm

Since 1935 California has enjoyed a remarkable cycle of discovery, which has placed the state in a very satisfactory position in regard to oil reserves. Most ol the geophysical plays have been drilled and it is possible that new discoveries must be made by the application of careful geologic and stratigraphic studies. During 1940 only one new field was discovered, which, although not of major importance, may lead to additional discoveries. During the year, 113 wildcats were drilled. New discoveries, extensions and a reappraisal of discoveries made in 1939 will not approximate over 50,000,000 bbl., as against an estimated withdrawal during the year of 224,000,000 barrels. Demand in terms of crude for 1940 was 632,000 bbl. per day as against 626,000 bbl. per day for 1939. Demand for gasoline was the same as in 1939, but the demand lor fuel oil increased 3.8 per cent. Compared with 1939, Japanese shipments decreased from 75,786 bbl, per day to 61,000 bbl. per day, but the balance of Pacific foreign shipments increased from 59,409 bbl. per day to 61,304. Total with-drawals from storage during the year will approximate 7,000,000 bbl., almost all of which is fuel oil. Drilling activity was slightly greater than in 1939 and accounted for 890 new producing wells as against 851 for 1939 (Table 3). Production averaged 611,900 bbl. per day as compared with 614.,842 bbl. per day for 1939. The productive acreage figure of the state was increased by 4000 through discoveries and extensions. New Discoveries Los Angeles Basin District Del Vdle Field.—Northwest of Newhall, where the first oil well in California was drilled, R. E. Havenstrite completed his Lincoln No. I well, flowing 390 bbl. of 50" gravity oil together with 7000 M CU. ft. of gas. Later the well was recompleted, after cutting off the gas, for 950 bbl. of 34" gravity oil. The type of structure from which this production is coming is a plunging anticline, complicated by faulting. The Lincoln No. I well uncovered approximately 180 ft. of net sand. This field contains a gas cap and its indicated productive area approximates 500 acres. An intensive wildcat drilling campaign is expected during this coming year in the district in the vicinity of the Del Valle field. Extensions and Deeper Sand Developments Los Ange1es Basin District Athens Field.—On the northwest plunge of the Athens structure, the Thorley Oil Co. completed its No. 12-1 well, flowing 250 bbl. of 3 2" gravity oil from a depth of 8097 ft. The area in which the well is located is complicated by faulting and it is impossible at this date to determine the importance of this deep-zone discovery.

Jan 1, 1941

By V. H. Whihelm

Since 1935 California has enjoyed a remarkable cycle of discovery, which has placed the state in a very satisfactory position in regard to oil reserves. Most ol the geophysical plays have been drilled and it is possible that new discoveries must be made by the application of careful geologic and stratigraphic studies. During 1940 only one new field was discovered, which, although not of major importance, may lead to additional discoveries. During the year, 113 wildcats were drilled. New discoveries, extensions and a reappraisal of discoveries made in 1939 will not approximate over 50,000,000 bbl., as against an estimated withdrawal during the year of 224,000,000 barrels. Demand in terms of crude for 1940 was 632,000 bbl. per day as against 626,000 bbl. per day for 1939. Demand for gasoline was the same as in 1939, but the demand lor fuel oil increased 3.8 per cent. Compared with 1939, Japanese shipments decreased from 75,786 bbl, per day to 61,000 bbl. per day, but the balance of Pacific foreign shipments increased from 59,409 bbl. per day to 61,304. Total with-drawals from storage during the year will approximate 7,000,000 bbl., almost all of which is fuel oil. Drilling activity was slightly greater than in 1939 and accounted for 890 new producing wells as against 851 for 1939 (Table 3). Production averaged 611,900 bbl. per day as compared with 614.,842 bbl. per day for 1939. The productive acreage figure of the state was increased by 4000 through discoveries and extensions. New Discoveries Los Angeles Basin District Del Vdle Field.—Northwest of Newhall, where the first oil well in California was drilled, R. E. Havenstrite completed his Lincoln No. I well, flowing 390 bbl. of 50" gravity oil together with 7000 M CU. ft. of gas. Later the well was recompleted, after cutting off the gas, for 950 bbl. of 34" gravity oil. The type of structure from which this production is coming is a plunging anticline, complicated by faulting. The Lincoln No. I well uncovered approximately 180 ft. of net sand. This field contains a gas cap and its indicated productive area approximates 500 acres. An intensive wildcat drilling campaign is expected during this coming year in the district in the vicinity of the Del Valle field. Extensions and Deeper Sand Developments Los Ange1es Basin District Athens Field.—On the northwest plunge of the Athens structure, the Thorley Oil Co. completed its No. 12-1 well, flowing 250 bbl. of 3 2" gravity oil from a depth of 8097 ft. The area in which the well is located is complicated by faulting and it is impossible at this date to determine the importance of this deep-zone discovery.

Jan 1, 1941