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By Harry R. Price, Bharat Doshi, Awni Qaqish, Abdul-Ghani Mekkaoui, Thaddeus Znoy, Ramesh Shukla

In 1992, a detailed inspection of the Southfield Sewer revealed a reach of approximately 0.8 kilometers in length, located directly below the freeway lanes, which was severely distressed. Failure of this section of the sewer would result in the closing of the busiest roadway in the state as well as the potential backup of sewage into homes and spilling into nearby surface waters. As such, repair of the distressed section required development of a procedure that would not jeopardize the conveyance of flow through the existing sewer nor impede travel on the overlying freeway. Based on these constraints, the DWSD and NTH team developed a repair concept that entailed the mining of a new, 3.05-meter (10-foot) diameter bypass away from the traffic lanes. The new bypass section was connected to the existing sewer, up stream and down stream of the distressed area, using a “top down” construction approach, that required only minimal freeway closures during weekend periods. This paper, prepared jointly by the Owner, Consultant and Contractor will describe existing conditions, design considerations and construction methods.

Jan 1, 2001

The ore, as sent to the sulphide mill, is a mixture, in varying proportions, of oxidized ore from above the 450-ft. level and sulphide ore from above and below (to date mainly from above) that level. The oxidized ore consists essentially of quartz, with varying amounts of kaolin and clayey material which passes into the slime and, in excess, creates a serious problem in settling. Pyrite may be present in small amounts. The gold is free and extremely fine.The ore, classed as sulphide, consists of pyritic material in a quartz gangue. The sulphides have been exposed to weathering, leaching by descending solutions and attack by ascending gases and actual burning. The alteration products occur in widely varying proportions and this variation adds to the difficulties in settling and control of grinding and flotation.Copper Minerals.-Chalcopyrite is the principal copperbearing mineral with smaller and varying amounts of covellite, which is sometimes associated with chalcocite, both these minerals being apparently of secondary origin.Examination of tailing by Dr. Stillwell has revealed all stages between clean chalcopyrite, chalcopyrite tinged with covellite, covellite with residual cores of chalcopyrite and clean covellite.The chalcopyrite is free floating, very few particles of clean chalcopyrite being observed in the tailing from granular flotation. The chief tailing loss is probably as chalcopyrite occurring as small inclusions in pyrite...

Jan 1, 1939

By H. C. Li

Mechanical models are established in accordance with the degree of mining on both sides of the coal pillar, and formulae were derived which calculated the superposition stress distribution and the width of the plastic region. The stability of the coal pillar was analysed and a reasonable size of coal pillar determined, in accordance with the elastic region rate. Further practical examples for the stability of the coal pillar are calculated and simulated.

Jan 1, 1992

By V. N. Rampton, C. F. Gleeson

"Exploration results over three overburden drilling anomalies defined by the Ontario Geological Survey in 1981 in the Kirkland Lake area, Ontario are presented. The anomalies come from lowland areas where overburden is thickest. By mapping the bedrock and surficial geology, by prospecting, humus sampling and shallow till sampling over the surrounding upland surfaces, one can initially evaluate such overburden drill anomalies without costly reverse circulation drilling. The drilling should follow, if necessary, only after surficial base data has been obtained. Preliminary work on these three properties has defined the presence of at least two styles of gold mineralization. One occurs in silicified zones in intermediate volcanics closely associated with northwesterly trending faults and shear zones. The second occurs in quartz-carbonate alternation zones in volcanics intruded by quartz-feldspar porphyry dykes. IntroductionThe three examples presented in this paper present first-hand information on an approach to the follow up of several geochemical anomalies that were found by the Ontario Geological Survey when they carried out reverse circulation overburden drilling as part of the Kirkland Lake Initiative Program (KLIP) in 1980 (Routledge et al., 1981). The initial approach is relatively simple, systematic, and cost and technically effective. It readies the properties for further exploration, or conversely, it could downgrade the properties as viable gold targets."

Jan 1, 1987

Thermal method of diagnostic as a nondestructive monitoring is based on data logging of infrared radiation from heated surface or from the associated thermal field. Monitoring of gearcases and motors hidden faults, such as, bearing degradation (deep-seated wears and tears, fretting wear, spalling and jamming solids of revolution) is closely related to high variations in temperature. The use of portable thermal imaging devices provides considerable advantages due to: easy remote access to the unit under test even when it is operating; minimum time required to obtain information and an opportunity for a real-time diagnosis of the tested subject's condition.

Dec 6, 2010

By Jarek Jakubec

The new euphoria in diamond exploration brings with it a need to understand the challenges that new projects can face in different stages of the development and risks that the commercial outcomes from the new projects fall short of expectations. In many cases, the problems are related to a poor understanding of the technical risks and a failure to adequately address them during the course of investigation. Failure to evaluate all disciplines to the same level of certainty could lead to a situation where the important issues are only identified late in the project development, resulting in costly delays and financial difficulties. The diamond projects located in Canadian Arctic, with its challenging environmental, geographical, social, political and geological contexts are especially sensitive to the high variability of the outcome. This presentation highlights some of the technical aspects that could be the leading sources of risk in diamond projects and could ultimately result in inappropriate mine designs, reducing the economic outcome.

May 1, 2006

By R. R. Lowery

An analysis of three 1-1/4-diam manufactured wire ropes of 6x19 classification was done to identify and describe reference conditions of new rope. Reference condition is of value when examining tested or retired ropes. Measurements of strand and rope pitch and of wire and rope diameter confirmed adherence of all ropes to those construction specifications. Mechanical properties of strength and ductility were determined by accepted methods for the ropes and wires from the ropes. Individual wires from one rope failed to meet minimum wire ductility values. Wire chemical composition varied in average carbon levels, from 0.70 to 0.78 wt pct, and in manganese content, from 0.45 to 0.80 wt pct. One manufacturer's product contained 1 to 3 wt pct Ni and Cr. Heavily wrought pearlitic steel microstructures were porous and contained inclusions. Cold work variations were evidenced by wrought grain width. Recorded anomalies reflected the condition of the manu-factured products. The report provides data that compare the three wire ropes studied, but cannot verify the effects that these conditions or anomalies have on rope service life.

Jan 1, 1983

Entry of personnel under a vertical raise bored hole is not standard practice in Australia. Where access is required below a rise, mining operations must be confident that they understand the capacity of the ground control specified and installed. Physical modelling was conducted on Callie mine to evaluate the performance of 5 mm steel wire weldmesh secured to the base of a vertical raise bored hole of 1.4 m diameter. Joint orientation data was used with Unwedge to calculate a series of potential wedges likely to form within the rise. The mass of the most likely wedges were then replicated by collecting rocks in 5 kg increments (¦10 per cent), which were allowed to freefall onto installed mesh at the base of a 40 m vertical rise. The results indicate that two sheets of mesh can retain a freefalling rock of at least 20 kg mass although rupture of strands can result. This paper outlines the test conditions, expected results based on theoretical calculations and actual outcomes of the testing.

Nov 25, 2010

By Gábor Csicsovszki

We have developed a novel method - at the laboratory scale - comprising an ion-exchange separation and a membrane-electrolysis step for the purpose of zero-waste regeneration of spent HCl pickling liquors originating from hot-dip galvanizing of common steels. It is aimed at the parallel regeneration of HCl and iron. Experiments revealed that iron can be electrodeposited at high current efficiencies by maintaining the following conditions: 0.04-0.08 M HCl, 500-1000 A/m2, 20°C and stationary electrolyte in a conventional cell. Zinc in the solution did not disturb the deposition of iron, however it contaminated the product and it poisons the anion-exchange membrane required to tackle acidity during electrolysis. For a preliminary separation, anion-exchange tests were carried out to produce pure iron solutions. Beyond the equilibrium studies, column experiments were carried out showing that low flow rates of the loading solution and the ~1.5 M HCl eluent are essential for separation.

Jan 1, 2006

By Wylie A. W, Mathew P. J, Eisler P. L

Field studies of the radiations backscattered by iron ores from a 60Co source of primary gamma radiation located in a borehole logging probe have confirmed thatthe P" factor, a ratio of high energy gamma ray intensities to low energy intensities in selected energy windows of the backscattered gamma-ray spectrum, is a valuable measure of grade for sedimentary iron ores of the Pilbararegion of Western Australia.Laboratory studies of model boreholes have shown that variations in borehole diameter and variations in bulk density of the formations have a significant influence on the measurement of P" ratios. If these influences 'are taken into account the mean ore grade in a new blast hole, for instance, can be predicted with a probe of suitable configuration to within 0·8 per cent Fe at the 95 per cent confidence level, while the grade of a single 120-cm split can be determined to within 2·6 per cent Fe. These results were obtained by pooling data from five blast holes covering the range of iron concentrations 20-68 per cent Fe and apply to the mean hole grades 54-68 per cent Fe.Results for two development holes were generally comparable to those obtained from individual blast holes95 per cent confidence limits of ±0·9 per cent Fe for mean ore grade and ± 4·1 per cent Fe for single splits. A greater number of data points is needed before these confidence limits can be further improved.The technique utilized to obtain these results was derived from a "multiband" approach to collection of backscattered spectral intensity data, an approach which permitted selection at the data processing stage of the most statistically significant P" ratios for the type of mineralization encountered in the field. The multiband technique also permitted selection of the most significant of another set of windows in the backscattered gammarayspectrum to measure a newly developed "S-factor", a ratio sensitive to borehole diameter. Another window provided information on bulk density. All these measurements were made with a single pass of the same loggingprobe.

Jan 1, 1977

By Edward P. Barrett

The production of sponge iron is one of the earliest arts in the metal¬lurgy of iron and steel. The idea of producing iron direct from ore at temperatures lower than the melting point of, the iron has persisted throughout the centuries. The purpose of this paper is to present a general picture of the methods, proposed or tried within the past 100 years, for producing sponge iron by treating hot ore with heated reducing gases. The abundant literature has been abstracted, and quoted freely. Publications concerning more detailed information on the various methods are referred to in the footnotes and in the bibliography.

Jan 1, 1949

By Joseph T. Singewald

The term "titaniferous magnetite" is used to designate those magnetic ores of iron that carry more than 2 or 3 per cent of titanium. Large and easily workable deposits of these ores occur in different parts of the world, and have attracted attention for many years. Under present furnace practice, however, the smelting of these ores is both difficult and expensive, and for that reason they are not accepted by furnaces, so that the deposits are practically worthless. The problem of finding a feasible method of utilizing these ores has naturally been attractive, and numerous attempts have been made to solve it. Experiments to that end embrace two lines of investigation. The one that has been the more frequently tried is the elimination of the titanium from the ores, so as to make possible their smelting in the usual way. The other is the devising of a method of smelting by which titaniferous ores may be reduced as economically as are non-titaniferous ores. The former method involves a physical process, the latter a chemical process.

Jan 1, 1913

By C Li, D O’Dea, R Moreno-Atanasio, T Honeyands

The behaviour of iron ore granules in the feeding process of sintering is significantly influenced by the material properties of the granulated mix. Therefore, the measurement of key material properties of the iron ore granulated mix is indispensable prior to the simulation of the sintering process based on the discrete element method (DEM). In this paper, three key property parameters of the iron ore granulated mix, apparent density, elastic modulus and rolling friction coefficient, were measured in laboratory-scale experiments. For different sintering processes, the moisture content of the granulated mix normally varies according to the specific requirements for granule size distribution and operating conditions. Therefore, understanding the effect of moisture content on the property parameters of iron ore granules is very helpful in accurately determining the property parameters for DEM simulation work. In this paper, six groups of iron ore granule samples with six levels of moisture contents were prepared through granulation and the trends in apparent density, elastic modulus and rolling friction coefficient with the increase of moisture content were plotted and analysed based on the measurement results. The results show that as moisture increases from 6.9 per cent to 9.1 per cent, the apparent density decreases from about 3000 to 2800 kg/m3. With moisture increasing within the same range, the elastic modulus first decreases from over 200 MPa to below 100 MPa and then reaches a relative constant value of about 40 MPa at higher moisture contents. Rolling friction coefficients are measured using two methods with both indicating a similar trend, with the rolling friction coefficient first decreasing and then rising as moisture increases from 6.9 per cent to 9.1 per cent. The relationship between µr and µ’r is assumed to be similar to that between static and dynamic friction coefficients.CITATION:Li, C, Moreno-Atanasio, R, O’Dea, D and Honeyands, T, 2017. Variation in property parameters of iron ore granulated mix with moisture content, in Proceedings Iron Ore 2017, pp 79–84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By R. Ward Stahl

Fire is still a scourge of the mining industry, although many precautionary measures have been and are being taken to reduce the incidence of fires and to combat them. Generally, the success of fire extinguishment is directly proportional to the speed of attack, and the speed of attack in turn is dependent upon the availability of materials and trained personnel. Preparations for firefighting are frequently neglected because they are considered emergency needs and do not contribute directly to coal production. Fire incites panic--a fact often overlooked--but such chaos can be minimized by training people in the use of equipment and procedures. Heat, smoke, and fumes hamper the approach to a fire; however, a relatively new technique of attacking fires with high-expansion foam may well contribute greatly to firefighting. The foam is transported to a fire and used at a considerable distance, thus permitting the firefighters to work more safely.

Jan 1, 1962

By R. V. Ramani

One area of study in the Coal Mine Injury Analysis project was to illustrate and enhance the ability of mine safety management personnel to apply analytical techniques to injury experience data and to justify requests for funds for safety enhancement actions on a cost/benefit and other quantitative basis. Four volumes of this final project report detail (1) the objective and scope of the mine safety management research, (2) the results of literature review, and case studies, and (3) models developed for mine safety management. The four volumes are titled as Volume III: Mine Safety Management, Volume IV: Analytical Techniques for Mine Safety Management; Volume V: Mine Safety Management Case Studies and Volume IX: Training Cost Model. In this volume, the following material is presented: (i) review of related literature, (ii) mathematical models to perform quantitative analyses of accident/ injury experience data using the tools and techniques of risk analysis, time series analysis, and the Markov process, and (iii) descriptions of the HDBSEL and ACIM programs which are used to perform accident/injury experience analyses and cost analyses, respectively.

Jan 1, 1993

By Tim O’Neil

“America’s mining industry brings good jobs to communities across America and provides the energy, minerals and equipment that are vital to our economic security and our way of life.” That was the surprise videotaped greeting from President George Bush at the official opening ceremony of MINExpo 2004in the Las Vegas, NV Convention Center. Jack Gerard reinforced the upbeat mood at MIN-Expo. He praised Nevada Gov. Kenny Guinn for his support of the mining industry, the state’s largest manufacturing sector. Gerard is the president and chief executive officer of the National Mining Association, the sponsor of MINExpo 2004.

Jan 1, 2004

By John C. Stankus

To improve mine roof bolt performance, Jennmar Corporation commenced the design and development of a new roof control sys- tem. This new system designated "Insta'l Compression", not only improves safety, but is more cost efficient due to reduced amounts of resin needed per bolt installation. In this paper the research and development of this new system will be outlined. Much of the information presented will be actual test data from various underground operations in Alabama, Kentucky, and Pennsylvania. The development of this system will also cover the design of a new expansion shell, resin compression ring, anti- friction washer, and upgrading of material specifications.

Jan 1, 1990

By D. Millgard

Dennis Millgard introduced the Session by hoping that participants to the Conference would also share their piling problems. He then invited the first speaker to present his paper. Paper 5.1. Pat Kelleher commenced by saying that he belonged to a one hundred year old firm that had experience in the New York Harbour area. They were often asked to assess the integrity of many waterside structures such as piers, walls, and docks which were deteriorating whilst still in use. The earliest structures, built in the 1800's, were on timber piles. These have now changed to Steel H and tube piles and concrete piles. Usually they were called in when the structure was showing signs of distress, or had reached the end of its life but could not be closed. In particular, they had found that marine borers had returned to New York Harbour because of the improved quality of the water. There is now a far greater incidence of attack on the timber piles than when the water was polluted. Repair is usually carried out by encapsulating the pile within the tidal range of about -2ft to +8ft (-0.6 to +2.4m). Reinforced concrete forms, reinforced fibre jackets, or nylon bags are used. Reinforced fibre jackets are used with a protective coat on the pile, while nylon bags prove the cheapest method.

Jan 1, 1991

By Jerry C. Tien

Changes and the pace of change in China’s coal industry have been extraordinary during the past several years. At least 35 of the 94 former coal bureaus have been restructured into different mining companies and groups. Some of the more productive and efficient ones were further strengthened through consolidation and expansions. And several have even formed, or are in the process of forming, strategic alliances with utility companies, railroads, ports and chemical companies to secure additional reserves and coal sales. In addition, the improvement in coal pricing during the past two years has enabled China’s coal industry to move ahead with some needed changes. Coal mining accidents, though, remain a major concern for the Chinese government. Accidents remain high even though the government has made efforts to shutdown more than 55,000 unlicensed, unsafe small coal operations throughout the country.

Jan 1, 2003

By Fritz J. Klingler

From site demolition, to design, to construction, Detroit's new Tiger Stadium project is required to be completed within a short 2 ½ years from award of the design-build contract. Such extreme schedule requirements together with somewhat difficult ground conditions at the site, resulted in several challenges in the design and construction of the deep foundation system for the stadium. During the geotechnical investigation, an intermittent water bearing sand layer was encountered overlying the hardpan at the site. As a result, some concern developed regarding the potential for collapse of caisson bells within this layer, as well as the potential for flooding of the caissons during drilling. Although sand and/or ground water was encountered within about half of the caissons, standard drilling and belling methods were used, and adverse conditions were controlled in almost all cases through expeditious drilling, inspection and concreting of the caissons. This paper will present a summary of the ground conditions, design and specification requirements, and construction methods used to successfully install the caissons for this project.

Jan 1, 1999