Search Documents

By A. A. Tytko, T. S. Golosinski

"The paper discusses the accuracy of magnetic inspections of corroded hoist ropes. It quantifies the error of measured LMA (loss of metallic area) caused by presence in the rope of ferromagnetic products of corrosion. The paper concludes that in mining practice this error is not significant. Hoist Rope Corrosion and its AssessmentCorrosion is one of the most common forms of wire rope wear. For ropes working in wet mine shafts, ropes used by the fishing industry and, in general, ropes working in humid and chemically active environments, corrosion wear is usually the prime reason for rope discard. In most mining applications, rope corrosion is accompanied by fatigue cracking of wires, abrasion of external wires, internal nicking and other forms of wear.Quantification of corrosion damage in ropes using standard inspection procedures and examination methods is very difficult. Qualitative comparisons are sometimes used to describe the degree of rope corrosion to compensate for the lack of quantitative measures (SABS 0293, 1996). If available, the results of magnetic examinations of ropes may be of help in assessing their corrosion weakening.Magnetic rope examination requires that the rope first be magnetized. After that, the rope magnetic flux and the leakage flux along the rope are measured. The first is assumed to be directly proportional to rope metallic area (LMA) and its changes are indicative of the rope’s loss of breaking strength (LBS). Existence of the second indicates existence of local faults (LF) in the inspected rope. As the corrosion of rope results in development of corrosion cracks and in loss of rope metallic area, both the LF and the LMA should be used to quantify the level of rope corrosion. More specifically, the changes to the amplitude of the LF signal are considered to provide qualitative information on rope corrosion (Hansel et al., 1990), while those of the LMA signal are believed to provide quantitative information (Geller and Rousseau, 1990; Golosinski, 1996)."

Jan 1, 1999

Single station group velocities of fundamental made Rayleigh waves over the period range 15-100 s are carguted for five provincial profiles of the West Pacific. Based on recordings of earthquakes around the West Pacific by the W~ (World Wide Standard Seismic Network) stations AFI (Afianalu), HNR (Honiara), WEL (Wellington), PAR (Raratonga) and RAB (Rabaul). The inversion of the derived dispersion curves for average shear velocity-depth structure of the crust, LID and LVL shows that (i) the over-all structure beneath the profile 'westernSamoa-Micronesia-Mariana' is in between that of regions 3 and 4 of Pacific Ocean (Yu and Mitchell, 1979), except that the velocity is slightly lower, (ii) the uppermost mantle beneath the 'Vitiaz Trench' profile between AFI and HNR is similar to that of region 2 of the Pacific - in other words, thin LID and thick LVL; (iii) the structure beneath the ' Ibnga-Keradec Ridge' profile has a thick crust with thick sediments, and LID-LVL velocity and thickness are similar to region 3 of the Pacific; (iv) beneath the profiles ' Tonga/ Kermadec Trench events-RAR station' the structure is intermediate between regions 3 and 4 of the Pacific Crean; (v) from decomposition of the 'Solomon-meriana' profile, the structure beneath the Cntong Java Plateau has a thick crust with thick sediments and the uppermost mantle is similar to that of region 3 of the Pacific clean.

Jan 1, 1990

By Baozhong Ma, Yonggang Wei, Shiwei Zhou, Bo Li, Chengyan Wang, Hua Wang

The effects of additives with Na2S, Na2SO4 and CaSO4 on phase transformation of nickel laterite ore in low-temperature reduction roasting process using carbon monoxide were investigated. The results showed that diffraction peaks of forsterite increased with increasing reduction temperature for 30min with the addition of 10wt% Na2SO4 and 50vol% CO, and diffraction peaks of forsterite increased with increasing the content of Na2SO4 at 900°C for 30min. Comparing the above three additives, phase transformation of nickel laterite ore were strongly influenced with the addition of 10 wt% Na2SO4 and 10 wt% Na2S. Calcium sulphide from the thermal decomposition of CaSO4 was carried out in the reaction product. SEM-EDS analysis result deduced that increasing the dosage of Na2SO4 from 10wt% to 15wt% could promote the polymerization of ferronickel and improve the grade of nickel in ferronickel.

Jan 1, 2015

By D. H. Wilson

"This paper examines the increasing need for mechanical-electrical people within the industry and some of the reasons why such a shortfall exists. It is suggested that, in part, it is image related. The present industry-education relationship in addressing the situation is examined and some thoughts are expressed on how these may be built on, in order to help solve the problem of attracting people to this critical area.IntroductionAs a long-time proponent of plant engineering and maintenance as a management function, I would like to review the progress made by the industry/ educational approaches in satisfying the needs in that area. In doing so, I would like to make the following points:1) that there has been an accelerating shortfall of mechanical-electrical people relative to the needs of the industry;2) that the condition will probably get worse before it gets better; ,3) that the past industry I educational approaches to alleviate the problem have met with limited success; and finally4) I would like to review some of the things being done and consider how these efforts might be extended."

Jan 1, 1981

By Mike Johnson, Greg Andrews, Niels Verbaan, David Dreisinger

"The Search Minerals Foxtrot project in Labrador represents a significant Canadian resource of rare earth elements rich in the sought after heavy rare earth elements (19.8% HREE/TREE). A preliminary economic assessment of the project indicated that the project is technically feasible and economically attractive. A variety of metallurgical test programs have been undertaken which have led to significant streamlining and simplification of the process flowsheet. The improved flowsheet should allow Search to reach production earlier and will use conventional processing equipment. The results of these test programs are presented and discussed in this paper INTRODUCTIONSearch Minerals Inc. (Search) is exploring and developing a number of deposits for rare earth element (REE) recovery in Labrador, Canada. The Port Hope Simpson District is in the southeast of Labrador and is highly prospective for heavy and light rare earth elements. The Foxtrot deposit sits within the Port Hope Simpson REE District (Figure 1), which is 70 km long by up to 10 km wide. The infrastructure available at Foxtrot is excellent; a deep-water port, air strip, and road and power infrastructure are pre-existing at St. Lewis. The three communities of Port Hope Simpson, St. Lewis and Mary’s Harbour are in close proximity to the site."

Jan 1, 2016

By Andrew M. Leszcykowski

A 1981 U.S. Bureau of Mines investigation indicates the Panamint Dunes Wilderness Study Area (WSA) has one active (intermittent) mine,--borrow pit MS 242 owned by the California Department of Transportation (Cal Trans). This mine produces cinders for road base and traction grit. It contains about 900,000 tons of inferred reserves. Examination and sample analyses indicate the Panamint Dunes deposit, covering about 480 acres of the WSA, may have silica resources and the Green Quartz Claim may have copper resources. Carbonate rocks occur in the WSA, but stone resources have not been identified. Adjacent to the WSA, the Big Four Mine contains 35,000 tons of inferred subeconomic zinc-lead-silver resources, and may have additional resources. Sample analyses indicate the Apple 1 Claim, also adjacent to the WSA, may have silver-lead-zinc resources.

Jan 1, 1985

By J. R. Bredell, J. Branehog, C. Coetzee, J. J. van Tonder

A nutating grinding mill, exemplified by the commercial HICOM mill, achieves efficient particle size reduction through the accelerated motion of the material charge within the nutating chamber. This design, characterised by high particle velocities and rapid charge circulation, offers a compact solution compared to tumbling mills. There have been concerns regarding the mechanical reliability of kinetic joints for certain specialised mining applications. Recognising the need to model internal forces in such systems, this study focuses on the uncoupled simulation using multibody dynamics and the discrete element method. The investigation employed a small-scale experimental test mill, referred to as the NuMILL, featuring a cylindrical chamber (140 mm internal diameter, 245 mm height, 6° nutation angle). Instrumented with an array of sensors, the NuMILL provided internal load data for validating the simulations. Experiments were conducted with an empty chamber or filled with charge material. Charge materials included coarse sand or steel pellets with a charge-to-chamber mass ratio of 0.25. The mill speed ranged between 100 to 700 RPM. Multibody dynamics modelled resultant inertial and frictional loads within 5%, while the discrete element method simulated the internal material contact loads with accuracies ranging from 1% to 19%. The combined simulation approach predicted the resultant forces in the critical kinetic joint within a 20% margin. Representing the charge using rigid lumped mass elements was also studied. The presented simulation techniques, validated against experimental data, offer a robust foundation for analysing larger systems, including the industrial-scale HICOM.

Mar 5, 2025

By Donald S. Macdonald

"I AM thankful for this opportunity to address the Toronto Branch of The Canadian Institute of Mining and Metallurgy. The Members of your Institute can have a great influence on the direction in which the mineral policies of Canada will evolve, and to assure that optimum benefits from our country's vast mineral resources will accrue to the nation as a whole and to all its citizens. Today, I want to: (1) offer an outlook on the mineral industry for 1973; (2) talk briefly about the role of minerals in the total economy; and (3) outline some of our thinking with respect to a national minerals policy for Canada."

Jan 1, 1973

It is proposed to consider a new access, mining and hoisting system for underground deposits, as an alternative to the commonly used decline or vertical shaft access. The proposed system offers fundamental improvements in gathering of exploration data, reduction of capital expenditure and significant savings in mine operating costs. The cost reductions are achieved through:superior orebody definition by Supersucker winzing on ore prior to the commencement of capital development; considerable reduction of capital development in waste; full capitalisation on all benefits of a raisebored excavation; introduction of rubber tyred skip and rubber tyred Mine Rapid Response Vehicle; introduction of simplified ore handling system and reduction of underground mobile diesel fleet; and introduction of minimum maintenance shaft concept. The system is applicable to deposits ranging from shallow, low dip angle, narrow vein, high-grade to bigger, massive type vertical mineralisations accessed from the surface, preferably from the bottom of an open pit; it is also suitable as a down dip extension of an existing underground mine. The system is highly conducive to mine automation and emerging trend aimed to increase the ratio of mined metal/mineral to mined waste. It offers substantial reduction in diesel exhaust gas emissions to the mine atmosphere.

Jan 1, 2000

By Jian Wang, Xiaoming Sun, Ming Jiang, Fuxin Shen, Chengyu Miao, Wenchao Zhao, Yong Zhang

The increased thickness of the coal seam leads to higher goaf roof collapse height. In contrast, the dynamic pressure from the mining of ultra-thick coal seams generates higher abutment pressures around the mined area and may affect the stability of roadways servicing these panels. To mitigate the deformation and damage issues in the roadways during the extraction of ultra-thick coal seams under a high depth of cover, researchers have proposed combining high prestress constant resistance support and roof-cutting technology (HPCR-RC). The deformation and failure mechanisms of the roadways during the extraction of ultra-thick coal seams under a high depth of cover, along with the mechanisms and field control effects of the combined support system, have been analyzed through theoretical analysis, numerical simulation, and field experiments. The research findings reveal that the high in situ stress, initial excavation disturbance, rotation, and subsidence of the fractured roof of the extra-thick coal seam led to significant deformation and damage in the roadways. High prestress constant resistance support compensates for the initial stress loss, reduces initial stress concentration, and absorbs deformation energy. Moreover, the roof-cutting technology severs the connection between the goaf roof and the roadway roof, disrupts the path of stress transfer, raises the level of roof backfilling in the goaf, and provides support to the roof, effectively alleviating the pressure on the coal pillar ahead and adjacent to the working face. Field experiments have confirmed the effectiveness of HPCR-RC, as indicated by a substantial decrease in surrounding rock deformation and support pressure within the roadways.

Sep 25, 2023

By Alfonso Rizo-Patrón, A. M. Gaudin

PREVIOUS studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector. The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest. In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector. The results obtained indicate that a I : I ratio of collector ion to activator ion gives optimum results, and that a 2:I ratio almost fails to achieve activation and flotation. Yet, a 2:I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion. To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful. The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids; they confirm that an adsorbed coating is inescapable. APPARATUS AND SUPPLIES The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz. The flotation machine was built according to the design of D. W. McGlashan.* It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel stator, as in the Fagergren laboratory machine. The air intake is controlled by a valve, and the cell consists of a beaker. The quartz was obtained from vein quartz stored in large chunks. It was first crushed to 20 mesh, then sized on a 28-mesh screen. The 20 to 28-mesh size alone was retained for use. This size was freed of coarse iron by passage through a Ball Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used. The barium was used as barium chloride, Baker's analyzed C. P. The oleate was used as sodium oleate. It was prepared from sodium hydroxide, Baker's analyzed C. P., and oleic acid purified by R. R. de Arellano3 in the laboratories at the Massachusetts Institute of Technology. The purification procedure was elaborated from the recent researches of Brown and Shinowara.2 It consisted in: (I) saponification of olive oil with potassium

Jan 1, 1942

By K. J. Bathe

The current version of the computer program ADINA/BM (Automatic Dynamic Incremental Nonlinear Analysis for the Bureau of Mines) for linear and nonlinear, static and dynamic finite element analysis of mine structures is described. The complete report is divided into four parts. In Part A the program solution capabilities, the finite element library, the logical construction of the program and storage allocations are discussed. In Part B the theory and numerical techniques used in the program are summarized. In Part C brief problem descriptions and solution results for some sample solutions that have been transmitted as data cases with the program are presented. In the last section of the report, Part D, the users? manual of the program is presented. Program ADINA/BM is a general effective tool for coal mine structural analysis. The program is an extension of the computer program NON SAP (which was developed under an earlier contract with the U.S. Bureau of Mines). The important additional capabilities of ADINA/BM are: (1) the occurrence of all elements is time dependent, (2) all elements can be used in geometric and material nonlinear analysis, (3) the truss element can be used in elastic-plastic analysis, (4) the three-dimensional element can be employed in orthotropic, elastic-plastic and cracking and crushing analysis, (5) the program executes an out-of-core solution and thus allows the analysis of very large and complex coal mine models, (6) the truss elements can be employed as 2-4 variable-number-nodes elements, (7) a rock material model has been implemented, (8) displacement constraint equations can be imposed in the solution, (9) more flexibility in specifying the incremental solution strategy and an acceleration procedure in the equilibrium iteration are available

Jan 1, 1978

By Clyde N. Baker

The paper describes procedures used to predict the settlement performance of drilled shafts constructed under slurry through water bearing deposits to a dense bearing strata, considering both side resistance and end bearing. A full scale instrumented drilled shaft load test on a Jersey City, New Jersey highrise project is used as a case history to compare with prediction.

Jan 1, 1991

By V. B. Tare, H. Schmalzried

The use of solid electrolytes for determining kinetic paraneters at elevated tevnperatures is pointed out. The reaction rate constant k1 of the phase-boundary reaction during oxidution of iron to wiistite by CO2-CO gas mixtures has been deternined between 850 nnd 975C, using ZrOz(+CaO) as an electrolyte. Values are between 1.4 x 10-a and 5.2 x 10 ole per sq ctn atm. The tzain difficulty is due to mixed potentials arising from side reactions at the electrolyte inteyface. In a number of papers the calcium-doped zirconia electrolyte has been used for the determination of thermodynamic data from measured differences in oxygen activities (or potentials) between two electrodes. The purpose of this note is to suggest the use of this solid electrolyte for kinetic measurements as well. The principle can be seen from Fig. 1. A thin and compact phase II (electron conductor) is fixed on a plate of gas-tight, polished ZrO2(+CaO) (I), which separates two compartments with different oxygen potential. p, is a constant reference pressure of oxygen (1 atm). The electromotive force of this galvanic cell is given by E = RT5 In pep, and pe is the oxygen partial pressure at the interface electrolytephase 11. If phase I1 is in equilibrium with the surrounding gas phase, p, = DR. If pg changes sud- denly to a value pi, p, and therefore the electromotive force, E, change as a function of time according to the phase-boundary reaction rate at the gas phase I1 interface and the transport processes inside phase 11. It is assumed that local equilibrium is established at the boundary electrolytephase 11, that the gas phase shows no concentration gradients, and that the con-

Jan 1, 1967

By J. H. Frye, J. W. Caum, R. M. Treco

IT has been suggested that: "Insofar as the hardening due to a solute depends upon the increase of lattice parameter produced by it, it is reasonable to suppose that this hardening might be related to the resistance which the pure solvent would offer to increase in its parameter."' It was further suggested that this hypothesis might be examined by comparing the hardnesses of analogous silver and copper alloys, since the stress necessary to produce a given lattice expansion is quite different in the two metals. Suitable data2,3,4 are now available on these alloys, and we shall proceed to an examination of the hypothesis quoted above. Hardness, Lattice Parameter and Ionic Overlap Increase in ultimate Meyer hardness has been plotted against increase in lattice parameter in Figs. I and 2. It is believed that most of the values are accurate within the limits indicated by the rectangles. These data are also presented in Table I. Ultimate Meyer hardness, P u, is defined by the equation: where L = load, D = diametei of an impression having the same diameter as the testing ball, which in this case is 4 mm. Increase in lattice parameter is defined as the difference between the lattice parameter of the solid solution and that of the pure solvent. The curves in Figs. I and 2 are based on equal solute concentration and an equal degree of plastic deformation pro duced by the testing ball. Hardnesses are corrected to a constant grain size for copper and silver alloys, respectively, and these two grain sizes are approximately equal. Furthermore, all solutes are from the same period of the B subgroup of the periodic table as their solvent. The question arises as to whether Or not lattice parameter is the only factor controlling the hardness of these alloys. There

Jan 1, 1943

By J. H. Frye, R. M. Treco, J. W. Caum

IT has been suggested that: "Insofar as the hardening due to a solute depends upon the increase of lattice parameter produced by it, it is reasonable to suppose that this hardening might be related to the resistance which the pure solvent would offer to increase in its parameter."' It was further suggested that this hypothesis might be examined by comparing the hardnesses of analogous silver and copper alloys, since the stress necessary to produce a given lattice expansion is quite different in the two metals. Suitable data2,3,4 are now available on these alloys, and we shall proceed to an examination of the hypothesis quoted above. Hardness, Lattice Parameter and Ionic Overlap Increase in ultimate Meyer hardness has been plotted against increase in lattice parameter in Figs. I and 2. It is believed that most of the values are accurate within the limits indicated by the rectangles. These data are also presented in Table I. Ultimate Meyer hardness, P u, is defined by the equation: where L = load, D = diametei of an impression having the same diameter as the testing ball, which in this case is 4 mm. Increase in lattice parameter is defined as the difference between the lattice parameter of the solid solution and that of the pure solvent. The curves in Figs. I and 2 are based on equal solute concentration and an equal degree of plastic deformation pro duced by the testing ball. Hardnesses are corrected to a constant grain size for copper and silver alloys, respectively, and these two grain sizes are approximately equal. Furthermore, all solutes are from the same period of the B subgroup of the periodic table as their solvent. The question arises as to whether Or not lattice parameter is the only factor controlling the hardness of these alloys. There

Jan 1, 1943

By A F. D C Varajpo, R C. Weba, C Volkmer-Ribeiro, C A. C Varajpo, N S. Gomes

This study relates to the spongillite deposits from the region of Jopo Pinheiro, in the north-west of the State of Minas Gerais, south-eastern Brazil. The deposits occur in shallow ponds (with a maximum depth of 3.5 m) on a karstic planation surface developed on rocks of the Spo Francisco Neoproterozoic Supergroup. Cenozoic detritic covers are associated with this surface. The field study of spongillite deposits from the Preguita and Avipo deposits revealed sedimentological and pedological similarities between the different deposits. They have a lenticular shape and contain different layers of sedimentary spicules intercalated with layers of quartz sand and clay minerals. Representative samples from the different layers investigated by X-ray diffraction, differential and gravimetric thermal analysis and infrared spectroscopy showed a range from three to 80 per cent of amorphous silica (opal) corresponding mostly to the sponge spicules in the sediments. Optical microscopic investigation determined that the spicules predominantly belong to the sponge Metania spinata. This species is represented by smooth megascleres (alpha type), prickly megascleres (beta type) measuring 240 to 450 mm in length, as well as the spiny microscleres; whereby the smooth megascleres are larger and thinner. The morphological variation of the spicules as well as the presence of more fragmented spicules towards the base of the deposits, portray a variation in texture and in the state of their preservation along the profile, suggesting environmental variations at the time of their formation and deposition.

Jan 1, 2008

Raphael PUmpelly, who became a member of the Institute in 1871, the year of its organization, and retained his membership for a long period, died at his home in Newport, R. I., Aug. 10, 1923. He is survived by a son, Raphael, Jr., and by two daughters, one of whom is the wife of Prof. Henry L. Smyth, of Harvard. Doctor Pumpelly was born in Oswego, N. Y., in 1835. He studied sciences and mining engineering in Paris and at Freiberg, later taking his Doctor's degree at Princeton. He was Professor of Mining at Harvard from 1866 to 1873. Doctor Pumpelly made geological explorations in many lands. In 1861-63, he conducted a scientific exploration for the Japanese government, and for two years thereafter carried on researches in central, western, and northern China and Mongolia. In 1864-65, he undertook a voyage of exploration across the Gobi desert, returning to Europe through Siberia. He was State Geologist of Michigan from 1869 to 1871; Director of the Missouri Geological Survey from 1871 to 1873; and Chief of Division, U. S. Geological Survey, directing the mineral industries division of the tenth census. He organized and directed the Northern Transcontinental Survey, 1881-84; directed the explorations inaugurating the iron ore industry of most of the ranges of Michigan and Western Ontario, 1897-1901; initiated and directed a physical-geographical and archeo-logical exploration of Central Asia under the auspices of the Carnegie Institution of Washington, 19034.2.

Jan 1, 1924

By S. R. Borrowman

This investigation by the Bureau of Mines was undertaken to develop information on the extractive metallurgy of thorite ores because potential ore bodies of this mineral have been found recently in Colorado, Idaho, and Montana. Basic information on thorite ore treatment that would be useful in appraising the potential of these and other domestic thorium resources was developed. The work was done mainly on thorite ore containing 3.87 percent ThO2 from the Powderhorn district, Colo., and on a composite sample containing 0.52 percent ThO2 from the Wet Mountains district, Colo. Limited tests of d corroborative nature subsequently were made on a sample containing 2.30 percent ThO2 from the Lemhi Pass area on the Idaho-Montana border.

Jan 1, 1962

By Christopher J. Bise

Volume II of this collection of research reports, entitled "Model Training Program," provides the framework and details for developing a tailored training program for a specific mine based upon documented human-performance deficiencies. To do this, several steps must be followed prior to program implementation: 1) background information must be gathered (database analysis), 2) direct observation of indicated problem areas should be conducted (safety sampling), and 3) separation of those deficiencies to be addressed through training from those which would be better addressed by workplace or equipment redesign (trainability assessment). Once training is determined to be the appropriate strategy for addressing the noted deficiencies, several approaches can be taken, depending upon whether the problem is related to repetitive work procedures in a predictable, a variable, or a dynamic workplace with a substantial amount of interaction between workers, equipment, and the environment. Although this volume and the subsequent seven volumes provide examples of how the training information was field tested using various strategies (for example, loss control, task training, etc.) and techniques (for example, microcomputer-based exercises, lectures, etc.), the ultimate selection of the delivery method is based on cost/benefit analysis. Therefore, the Model Training Program has incorporated a Training Cost Model as a desirable component.

Jan 1, 1993