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By Taylor G. H

The Triassic Ipswich (SE. Queensland) coals are of bituminous rank. The more exact rank of individual samples was determined by measuring the reflectance of the vitrinite. While in general the rank of the coals increases with stratigraphic depth, minor reversals, probably related to igneous intrusions, occur.The Ipswich coals form a coherent group so far as petrographic type is concerned. All are comparatively rich in vitrite and clarite, cutinite being the common maceral of the exinite group. The mineral contents of all the coals are comparatively high, clay and quartz being most abundant. The coals appear to be of essentially autochthonous origin, and to have been formed under conditions of fairly rapid subsidence.While the use of the coals is at present restricted to combustion, most have pronounced coking properties, as would be predicted from their petrographic composition and reflectance. However, the high mineral content of the coals would be a limiting factor in their use for coke-making.INTRODUCTIONDuring the last ten years, the Division of Coal Research, Commonwealth Scientific and Industrial Research Organization has carried out an extensive investigation of Australian coals, providing a wide range of analyses of most of the important of them. Special attention has been given in recent years to Queensland coals.Most seams were sampled as a number of subsections, enabling the internal variations, as well as the overall properties, to be assessed. The lenticularity of many of the mineralrich layers may tend to limit the significance of the samples, particularly in respect of ash yield, but although the vertical distribution of mineral matter may vary considerably from one sampling position to another, the lateral variation of the total mineral matter in the whole seam may not be great.Apart from extensive chemical analyses and utilization...

Jan 1, 1963

By Parker A. J, Grimsey E. J

Studies have been carried out on the dead roasting of a copper-iron and a copper-nickel-iron sulfide concentrate, followed by segregation roasting with coal and leaching with either curpric sulfate in aqueous acetonitrile or cupric chloride in brine solution to preferentially solubilize copper. The effect of dead roasting and segregation roasting conditions on the overall leaching of copper and the separation of copper from iron and iron and nickel is reported. An excellent separation of copper from iron and a good separation of copper from iron and nickel can be obtained provided sulfur is removed to 0.5 per cent or less during the dead roast and provided the coal addition and temperature of the segregation roast are near the minima required for the segregation of copper.

Jan 1, 1983

By Lee W. Abramson, William H. Hansmire

The H-3 Project is planning, design, and construction of a 10-mile (16 km)-long final segment of new highway that traverses the Koolau mountain range in Oahu. Interstate H-3 traverses North Halawa Valley on one side of the Koolau Mountains and Haiku Valley on the other side. The project includes a tunnel through the mountain range. The one-mile (1.6 km)-long twin-bore Trans-Koolau Tunnel will have two lanes in each direction. The total roadway width including shoulders in each bore will be 38 ft (11.6 m). The geologic and geohydrologic conditions along the alignment present a variety of tunneling problems. Geologic conditions consist of volcanic materials deposited generally in fairly thin basaltic layers. These volcanic materials generally weather down to "MH" soils which are compressible but relatively strong. Perched ground water that is recharged by heavy rainfall is present in the mountains. The paper presents results of initial geologic surveys and exploratory boring, and plans for exploratory tunneling and testing programs. A site specific classification method developed to characterize the weathered profile is presented.

Jan 1, 1989

By R. D. Lindsay

Pamour Porcupine Mines, Limited has been actively engaged in the ''Custom Tolling'' of Gold-Bearing materials throughout the past decade. Experience acquired in this area was utilized to design and commission a custom gold milling facility at its operations in Timmins, capable of:(a) Accepting a bulk ore test sample at the rate of 150 t/d for crushing, sampling, and metals analysis;(b) Processing gold-bearing ores at a rated capacity of 150 t/d, to produce a goldbearing sulphide concentrate;(c) Processing free milling gold ores at a rated capacity of 80 t/d for total cyanidation;(d) Cyaniding custom gold flotation concentrates at a rated capacity of 80 t/d; and(e) Processing of complex gold/copper or carbonaceous ores, requiring an impurity flotation concentrate separation stage prior to cyanidation, at a rated capacity of 100 t/d.Items considered in the process design and development included:- various gold ore types available for processing;- flowsheet flexibility required;- sampling strategy as related to head grade determination and metals accounting; and- contract considerations.This paper highlights how these various considerations were used to design Pamour's ''Custom Gold Milling Facility''.

Jan 1, 1987

By Lorenzo Pellegrini

The respect of EPB reference pressure during TBM advance and hyperbaric activities, the complete and effective filling of the annular gap between tunnel lining extrados and the excavation section and a well organized monitoring system, to control surface settlements and ground distortion, are items of utmost importance in EPB tunnelling process. The paper describes how these concepts have been applied while excavating in the difficult underground conditions found at Sao Paulo (Brazil) during the execution of the Sao Paulo Metro Line 4-Lot 1. In this project, the annular gap has been filled by two components type, cement grouting. The back feed of the extensive monitoring campaign carried out to check the surface settlements during the excavation and hyperbaric maintenance operations will also be described in the paper.

By R F. G Phelps, C J. S Sangster, G S. C

Narrow vein metalliferous mining in the UK has a long history, but there are only two small gold operations at present (Clogau and Gwynfynydd). Four further gold properties are at various stages of evaluation (Calliachar, Cononish, Curraghinalt and Maestryfer). The South Crofty tin mine closed earlier in the year. Narrow veins are exploited underground and are challenging to evaluate because of their geologically variable nature. They are generally less than 3 m wide, discordant, of variable dip (

Jan 1, 1998

By A. J. MOORE

When the writer first saw the square-set timbering, he was at once impressed with the fact that the frames made by the sets, along the lode and across it, were composed of panels with rectangular openings, and it was puzzling to understand howsuch a collapsible construction could resist pressure that came unevenly on it. Later he learnt that the sets did not satisfactorily resist such pressure, but mullock filling had, to a great extent, to undertake this duty for them. So it appeared that the setswere practically an expensive scaffolding, enabling the miners to work in the face and carry the stope forward, till the filling was put in behind them to take the pressure of the roof and sides of the excavation. Of course some of the pressure is takenby the sets, but this is because "the set timbers prevent the filling being done perfectly; if it were practicable to remove the sets before filling, the filling by itself would more effectively support the back and wall, than do the combined sets andmullock. On the whole, therefore, the sets can hardly be said to be of much benefit where pressure has to be resisted. Despite this, the system has been of immense service in mining wide lodes, but for all that, it can only be pronounced a makeshift.This is no reflection on Deidesheimer, the famous originator of the square set, for, as will be shown later on, this way of...

Jan 1, 1912

When perusing articles which treat of mining geology, and when talking with miners on the field, one is at times unable to follow the exact thoughts intended to be expressed, owing to the introduction of occasional technical words, the meanings of which are not thoroughly understood either by the speaker or by the hearer, or possibly by both and laymen at times accuse their technical brethren of attempting to confuse them by employing unusual words in their conversations and writings. Technical words are necessary adjuncts to all arts and sciences. They creep into our language, frequently unnoticed by those who employ them, as being more concise and convenient than longer sentences to explain frequently recurring expressions. In many cases these words give the finest shades of meaning, such as aglomerate and congzomerate, but in others they are extremely ambiguous, for instance black sand, which in some places means ilmenite, in others, chromite, tourmaline, cassiterite, in fact, any black mineral occurring in the form of sand. Then, again, much confusion is cansed by the same rock or mineral having different names, e.g, jlu01'spa'i', which is known as cand, cann, cauk, kawk, blue-John, Derbyshire spar, &c. The multiplicity of local names is of course chiefly found among the more common minerals, which are widely distributed some people have a propensity for using words the meanings of which they understand as little as' they do how to pronounce them. We have heard such persons speak 'of vughs as "bugs," and oxides as "ox hides," and to show that there was no mistake in their intentions, we have seen these and other words written in the same way as they were pronounced. Then, again, some persons, relying more on examples than definitions, get a very vague idea as to what the true meaning of a term may be the word dimite is an example in point, which we have frequently heard applied to any dyke rock that the miner was unable to recognise as granite in fact, he uses the word in a general sense, just as the field geologist provisionally employs the word " greenstone " for certain rocks, until he has an opportunity of thoroughly investigating their character.

By H. T. Kennedy, J. E. Little

An empirical equation for the prediction of the viscosity of several pure paraffin hydrocarbons and nitrogen is presented. It involves temperature, pressure and six constants of the material, and it applies reliably to both liquids and gases. The equation is similar in form to van der Waal's equation of state. For the paraffin hydrocarbons methane through r-hexane and nitrogen, an average absolute deviation of 1.9 percent was obtained on 1,006 data points described in the literature by 14 authors. When this equation is extended to complex, liquid hydrocarbon mixtures, a correlation was obtained with an average absolute deviation of 9.9 percent. INTRODUCTION Equations describing the flow of gas and liquid through porous media contain the viscosity coefficient of the fluid. If other pertinent variables remain constant, the volume rate of flow is inversely proportional to this coefficient. In dealing with condensate fluids and volatile oils, however, the compositional effects resulting from changing pressure materially affect the viscosity. The effect of compositional changes also may be significant in certain secondary recovery or pressure maintenance processes, notably miscible displacement or gas injection. Early attempts to describe the performance of reservoirs utilized a volumetric material balance method wherein gas and liquid in the reservoir were identified as produced gas and liquid at the surface. This method of analysis proved adequate for reservoirs at moderate temperature and pressure that contained gas with moderately low amounts of condensable materials. The volumetric material balance procedures for "black oil" reservoirs leave much to be desired when applied to condensate and volatile oil reservoirs because phase behavior and compositional changes are relatively more important in these cases. The alternative is a compositional material balance, which in turn, requires a correlation of properties of the reservoir fluid with composition. This paper supplies this correlation in regard to viscosity, for reservoir crude oils. REVIEW OF LITERATURE The literature contains many empirical equations describing the effects of composition, temperature and pressure on the viscosities of pure liquids and binary liquid mixtures. However, the applicability of a majority of these equations is limited to very low pressures and to a small number of systems. Most of them, when applied to complex hydrocarbon systems, are of little value. The lack of utility of the majority of equations results from the fact that they were developed to show the separate effect of temperature, pressure or composition on viscosity, but not to predict the viscosity as a function of all three variables. And with the few exceptions noted below, they were developed to apply to much simpler systems than hydrocarbon mixtures. Eakin1 developed an equation for the viscosity of pure light hydrocarbons applicable in the gas, liquid and dense fluid regions, and in its most general form is written as µ - µo =A(ebP - e-cpk) The pure component viscosity at atmospheric pressure and temperature T, µo, was calculated using the Sutherland equation: µo = BT3/2/T + S The constants in Eakin's equation permitted the term e-CPk to become quite small at high densities (above 0.215 gm/cc), and the general equation would simplify to

Jan 1, 1969

By Jack Eloranta

The winning of metals often requires fine grinding of very hard ore. The US Bureau of mines measured compressive strengths exceeding 100,000 PSI (700 MPa) in Minnesota taconites. Grinding down to 300 mesh (50 µ) is required for some fine-grained taconites. While other metal ores may not be as strong, significant grinding costs are the rule rather than the exception. One author recently reported that a 7% drop in grinding costs would fully offset a doubling of the drill and blast budget. Another author found that drill and blast costs were 13% of the costs of producing iron ore concentrate while fine crushing and grinding were over 60% of the cost of producing concentrate.

Jan 1, 2013

By S. O. Bada

Coal samples taken from the No. 2 Seam and No. 4 Seam in a South African colliery were tested in a rotary triboelectrostatic separator. The two-stage triboelectrostatic separation results using the -177 µm size fraction reduced No. 2 Seam coal containing about 30.4 per cent ash to a clean product of 8.9 per cent and 13.1 per cent ash with combustible recoveries of 9.6 per cent and 30.7 per cent respectively. The same separation approach on No. 4 seam feed coal, which contained 36 per cent ash, produced a clean coal product with 10.8 per cent ash at a combustible recovery of 6.0 per cent. Petrographic tests show a significant improvement in the vitrinite content and a reduction in visible minerals encountered when using the triboelectrostatic separator, with about 53 per cent vitrinite reporting to the clean fraction for No. 2 Seam compared to the feed content of 21 per cent, and a 54 per cent vitrinite in the clean No. 4 Seam from a feed content of 21 per cent. Significant sulphur reductions were also observed after separation in both coal samples, with a better separation in the second-stage coal products.

Jan 1, 2012

By Louis D. Huntoon

AFTER the completion, in 1905, of the Hammond Mining and Metallurgical Laboratory of the Sheffield Scientific School, Yale University, it became necessary to secure and assay a large assortment of ore-samples, and to arrange the results in such a manner as to admit of use with the least amount of work on the part of the instructor. At first, pulp-samples, together with their respective assays, were secured from the mines, smelters, and public assayers, but this practice did not prove satisfactory. It was not only difficult to secure a sufficiently large supply of material, but it was also impossible to secure the proper assortment required for instructing students. It involved considerable work for the donors to select the samples and furnish a record of the assays, and also for the instructors to examine each pulp and determine its character. Some of the samples did not contain a sufficient quantity of pulp for the student to check his work in case his first assay did not correspond to the record. In order to increase the number of samples and to vary the character of the material, pulp-samples were later mixed with barren rock and with sulphides, but this method also was unsatisfactory and has been discontinued. At present., small lots of ore are secured by gift or purchase from engineers, public assayers, and the managers of mines, mills, and smelters. These lots weigh from 10 to 100 lb. each, and are rarely finer than 0.25 in. in size. The larger samples permit of a careful study by the instructor in order to determine the best method of assaying to be followed. In universities in which assaying is taught the record of the samples should fulfill the following requirements

Nov 1, 1909

A process was developed, on a laboratory scale, for the removal of iron oxides from Weipa pisolitic bauxite. The technique involves the chemical reduction ofthe iron oxides by carbon, followed by selective removal of the iron species by acid leaching or chlorination.To remove more than 90 per cent of the iron it is necessary to reduce the iron oxides substantially to iron metal by heating the bauxite, pre-calcined at 650-800°C, with reactive carbon at 1040-1100°C. Reduction proceeds via the intermediate formation of hercynite (FeO.Al2O3) and difficulties have been encountered in reducing hercynite formed under less favourable reduction conditions.Following reduction, efficient selective removal of iron species is readily effected by acid leaching using dilute hydrochloric acid at 100°C, or chlorination at 500-750°C using Cl2, Cl2/N2, or Cl2/N2/CO mixtures.After removal of unreacted carbon, the final products contain 0·5-1.0 per cent Fe203 and 87-92 per cent Al203.

Jan 1, 1971

By Brendan Henry

The Canada Line is a 19km long automated light rapid transit system with 16 stations in Vancouver, BC, Canada. The Concession was awarded to InTransitBC to design, build, partially finance, operate, and maintain the system for 35 years. The project must be complete by November 2009 to be ready for the 2010 Winter Olympics to be held in Vancouver and Whistler, BC. The bored tunnel section consists of 2.45 km of twin bored tunnel and 3 stations. The station work is limited to the excavations and temporary support necessary to facilitate the bored tunnel works. A joint venture between SNC-Lavalin Constructors Pacific and SELI (SSJV) has recently completed the design and construction of this section. Work for the bored tunnel commenced in November 2005 with shoring and excavation works for the tunnelling operations pit that will become Olympic Village Station and will be completed in the spring of 2008. The tunnels were driven with a 6m diameter Earth Pressure Balance Tunnel Boring Machine (EPBM) and lined with 250mm thick, 5.3m diameter precast concrete segments. Seven hundred and fifty meters of each tunnel were driven through glacial and interglacial deposits of sand, silt, and clay with granitic boulders. The paper discusses the challenges faced in negotiating these soils which contained unforeseen geological conditions. These conditions were overcome by developing a systematic approach to Risk Management that included thorough risk assessments, regular risk management meetings with the participation of two of the world?s leading EPBM experts, Professor Eisenstein and Professor Kovári, and by the ability of the construction team to effectively analyze and mitigate problems.

Jan 1, 2008

By C. W. Davis

This paper is the second of a series of progress reports on a study, of the hydrometallurgy of manganese which is being conducted in an endeavor to make possible utilization of the large deposits of low-grade domestic manganese ores that occur in several States. There are at least four processes in which a knowledge of the action of SO2 gas on manganese oxides at elevated temperatures may prove of value. One ,of these involves dissolution of manganese from ores. The Bureau of Mines has investigated the hydrometallurgy of manganese by a process in which SO2 gas, a waste product at many smelters, is passed into water to form a solvent for manganese. Although Several manganese minerals acre readily dissolved, rhodochrosite (MnCO3) was attacked but superficially.§. Recent experiments have shown that a roast at 650 to 900°C converts the manganese of rhodochrosite to a form that is quickly dissolved by a weak SO2 solution. Introduction of smelter gases containing as much as 5 per cent SO2 during such a roast would not add much to the cost of the operation and might result in the formation of considerable water-soluble manganese sulphate.

Jan 1, 1930

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

By C. W. Davis

This paper is the second of a series of progress reports on a study of the hydrometallurgy of manganese which is being, conducted in an endeavor to make possible utilization-of the large deposits of low-grade domestic manganese ores that occur in several States. There are at least four processes in which a knowledge of the action of S02 gas on manganese oxides at elevated temperatures may prove of value.

Jan 1, 1930

By Hookings H. J

UNDER a contract relating to the sale of a Broken Hill concentrate, the differentiation between granular and slime concentrate is determined by the proportion of the material which will pass a 200-mesh (I.M.M. standard) screen, and this has led to considerable attention being devoted to the question of laboratory sizing tests with screens of this order.It was found that many of the screens turned out by the makers during the war, and also since its termination, did not conform with the I.M.M. specifications as closely as some supplied in pre-war days. A perfect screen is hardly to be expected, but when the above contract was framed the parties anticipated that, by special care being taken during manufacture, a screen at least as good as the best pre-war screens would be available. This, however, has not proved to be the case, and the large irregularities in screens recently supplied render them useless for sizing determinations under the contract. The makers were approached through the Institution of Mining and Metallurgy, London, with the view of obtaining a few screens conforming as closely as possible to the 200-mesh I.M.M. standard, and in response to a request twelve pieces of screen were...

Jan 1, 1922

The 2003 SME Annual Meeting and Exhibit will take place Feb. 24-26 in Cincinnati, OH. The meeting will feature a host of special symposia and programming geared toward the industrial minerals and aggregate industry sectors. This programming focus is particularly relevant for this annual meeting, as it will be hosted in the center of America’s transportation hub and industrial mineral center. Cincinnati, located on the Ohio River, is key to the movement of America’s supplies and construction material needs.

Jan 1, 2003

By W. G. Huang

To recover the coal resources of high-sulphur anthracite in Jincheng Mining Area, underground coal gasification (UCG) of No. 15 seam in Fenghuangshan Coal Mine was proposed. The feasibility of the project was confirmed by investigations of occurrence conditions, coal properties, and roof conditions, as well as experimental studies and theoretical analysis. It was found that UCG technology is appropriate to be adopted in the mining of the No. 15 seam, due to the stable rock conditions, simple geological structure and hydrogeology, the high carbon content of the coal, non-cohesiveness, medium-thermal stability, high ash fusion temperature, and weak reactivity with CO2. Further factors are the characteristics of the immediate roof, which consists of 9.11 m of limestone and mudstone with a compact structure and low permeability, and 4.27 m of dominantly mudstone with low permeability.

Jan 1, 2012