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By F. K. McKean

Introduction The present paper may be considered as a sequel to a paper, A Process for Cleaning Molybdenite .Concentrate, which was presented by the author at the annual meeting of the Institute last year. In that paper, a description was given of the laboratory work leading up to the adoption of a new process for treating complex molybdenite ores of the Molybdenite Corporation of Canada. A bare outline of mill performance with the new flow-sheet was included. With this writing, the purpose is to describe the highly interesting work of translating laboratory experience into mill practice, to show what changes were required in design to put the scheme on an operational basis, and to point out the gratifying improvements in mill products which resulted from the new procedure. The process has been placed in operation at the La Corne mine of the Molybdenite Corporation of Canada. This mine was operated during the war by Wartime Metals Corporation, and, earlier, by the Molybdenite Reduction Company, which installed a small plant. The property is situated on the highway from Amos to Val d'Or, Quebec. The claims held by the Company are at the boundary between La Corne and Vassan townships.

Jan 1, 1947

Most types of nuclear power reactors use uranium dioxide fuel. Power reactors using natural uranium dioxide fuel are of special interest to countries such as Australia that have their own uranium supplies. A wide range of uranium dioxide powders can be fabricated and the ideal one flows readily, presses without the need for binders or lubricants, sinters to the required density and gives low reject rates at all fabrication stages. Sinterable uranium dioxide is usually produced via the ammonium diuranate route.The Australian Atomic Energy Commission is aiming to demonstrate production of nuclear grade uranium dioxide from Australian concentrates, improving technology where possible. Details are given of the dissolution, solvent extraction, precipitation, filtration, drying, and· calcination-reduction steps. Solvent extraction from sulphate media is also under study with a view to developing a process to produce a nuclear grade product at the mine treatment plant site.

Jan 1, 1970

By M P. Simpson, J L. Mauk

The Golden Cross, low-sulfidation, epithermal deposit shows a number of features that are directly or indirectly related to boiling hydrothermal fluids. Occurrences of lattice calcite and their quartz pseudomorph equivalents in veins, and occurrences of adularia in veins and in the surrounding altered rocks in the vicinity of ore, are both direct evidence of deposition in the presence of boiling hydrothermal fluids. Loss of carbon dioxide causes calcite deposition (platy variety) near the level of first boiling, while adularia deposits due to the attendant pH increase along the cooling flow path. Indirect evidence of boiling include crustiform-colloform quartz banding, late massive calcite veins, clay-carbonate alteration in the shallow and peripheral parts of the ore zone, and the restricted vertical interval of precious metal mineralisation. The colloform quartz banding strongly resembles the banding in amorphous silica deposits found in geothermal surface pipes. This implies that fluids ascending the Empire Vein structure were saturated in amorphous silica. If so, then they must have undergone phase separation, which initiated at considerable depth (e.g. =1000 m) and very hot temperatures (e.g. =300¦C). On the basis of stable isotope data, late massive calcite veins appear to have deposited from CO2-rich steam-heated waters. Calcite deposited along heating paths as these waters descended into the upflow zone during late stage collapse of the hydrothermal plume. In active systems, such steam heated waters form by deep boiling. The high CO2 contents of these waters promote hydrolytic alteration and the formation of clay-carbonate alteration. Reaction path modelling using CHILLER and a deep, Broadlands-Ohaaki water as an analogue, shows that minerals deposit along boiling flow paths over discrete spatial intervals. Calcite and adularia deposit near the site of first boiling, followed by gold and then by amorphous silica. For deep boiling starting at 300¦C, these minerals deposit over a path length that exceeds 1000 m. The distribution of banded quartz and gold at Golden Cross are consistent with such a boiling model. However, the elevation of first boiling must have fluctuated over 500 m to account for the coincidence of lattice quartz (pseudomorphs of platy calcite) and adularia, crustiform-colloform silica and gold over distances of a few centimeters in veins. We deduce that a downward propagating boiling front and expansion of two-phase flashing in a flowing water column occurred during episodes of high vertical permeability and fluid flux in the Empire vein structure.

Jan 1, 2000

By George H. Tousley

As a member of the vast fraternity of those that supply and service the mining industry, I can assure you that we are amused, amazed, and horrified at the poor drilling and blasting practices of a great number of operations. Yes, ?horrified?. After all, that is our product you are using and abusing. We all know that drilling and blasting is expensive. In some operations D & B costs may exceed excavating or hauling costs, or both. At any rate, it is the only portion of the whole operation that could be said to directly affect other costs. There is no argument that it affects excavating costs. If the overburden and/or product is drilled and hauled, it affects haulage costs. It can easily affect milling costs, if more or less fines is important. And poor fragmentation affects crushing costs. If scalping is done ahead of the primary crusher it can affect production. As has been pointed out, the D & B operation itself is costly, and therefore should lend itself to close scrutiny. Anyone that could immediately decrease haulage costs by 10% would be a hero with any mining company.

Jan 1, 1976

By Charles Catlett

(Chattanooga Meeting, October, 1M.) THE terms " developed " and " undeveloped " are necessarily relative and cover a wide range; but the latter is here applied to cases in which the information at hand falls short of a clear demonstration of values, and conclusions must be reached from a study of the geological conditions of the particular deposit, interpreted in the light of similar and closely related deposits. Such an inquiry might be characterized as an effort to reach reliable conclusions from insufficient data. But the engineer engaged in commercial work finds himself often face to face with apparently such problems; and while he may realize with regret that a small amount of intelligent development would add enormously to the value of his conclusions, he is compelled to recognize the demand of a business situation for a prompt decision as the basis of immediate action. In a case within my knowledge, the question involved was the purchase of 50,000 acres of coal-land, and 10 days was the limit within which this question must be decided. Of course, it was impossible to make a satisfactory examination within that time; but the 'instructions were "to make the most complete examination and the most positive recommendation possible." Such instructions are often given; for, no matter how much time an investor may have, he is likely to put of his decision until the last moment, and then discover that he needs more light and advice. It does not follow that engineers, after full explanation and mutual understanding of the situation, should decline to undertake examinations thus limited. In the case just mentioned, while only the broadest view was possible, half the time available was sufficient to show that the property was a good purchase. The timber alone was subsequently resold for more than the entire purchase-price of the

Mar 1, 1909

By Steven Rupprecht

"The South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (the SAMREC Code or the Code) sets out minimum standards, recommendations and guidelines for public reporting of exploration results, mineral resources and mineral reserves in South Africa. The Code is being rewritten and updated, with work on-going since 2013. The revision is being undertaken to ensure the Code remains relevant, incorporates developments within the international mining industry and keeps abreast of technology. Some of the changes and their reasons are discussed. INTRODUCTION The South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (the SAMREC Code or the Code) sets out minimum standards, recommendations and guidelines for public reporting of Exploration Results, Mineral Resources and Mineral Rreserves in South Africa. The Code is being rewritten and updated, with work on-going since 2013. The proposed 2016 update is not significantly different from previous versions of the Code. The revision is being undertaken to ensure the Code remains relevant, incorporates developments within the international mining industry and keeps abreast of technology. The Code sets out minimum standards, recommendations and guidelines for public reporting. However, reporting may be unclear, ambiguous, selective, obscure, distorted or unintelligible. Part of the purpose of the update is to provide better guidelines to Competent Persons (CPs) to ensure that the material information is being reported and that reporting is transparent in accordance with the guidelines of the Code. The information provided should, as required by the Code, be adequate to inform the “reader/investor or potential investor to make a reasonable and balanced assessment of the significance of the information”. The Committee for Mineral Reserves International Reporting Standards (CRIRSCO) highlights the importance of the reporting Codes, as provided from a quote from their website (www.crirsco.com): The mining industry is a vital contributor to national and global economies. It is a truly international business that depends on the trust and confidence of investors and other stakeholders for its financial and operational well-being. Unlike many other industries, it is based on depleting mineral assets, the knowledge of which is important prior to the commencement of extraction. It is therefore essential that the industry communicates the risks associated with investment effectively and transparently in order to earn the level of trust necessary to underpin its activities."

Jan 1, 2015

Three main divisions of the Proterozoic are recognized in the North-West Division of Western Australia. These are referred to, in order of decreasing age, as the Mt. Bruce Supergroup, the Bresnahan Group, and theBangemall Group. The stratigraphy and distribution of each is described, their relative ages discussed, and a brief geological history of the whole area is presented.

Jan 1, 1966

By Haigh J. E

An accurate measure of the earth's magnetic field can be made in a few seconds with the portable proton precession magnetometer. Such an instrument increases the applicability of the long successful method of magnetic prospecting for minerals. As an example of the usefulness of the proton magnetometer, a survey over volcanic rocks near Apsley (Tas.) was made.INTRODUCTIONA completely portable magnetometer whose operation is based on the free precession of polarized protons in the earth's magnetic field, is now available on the market at a price competitive with magnetometers based on the classical physical principles. The ease, accuracy, rapidity, and reliability with which measurements of the earth's total magnetic field can be made with the proton precession magnetometer, led to the try-out of the instrument in an actual field problem so as to evaluate fully the capabilities of the instrument. Such evaluation is important, because the history of magnetic prospecting has shown that whenever significantly improved instrumentation has been introduced, prospecting costs have been substantially cut and many areas in which the prospecting costs were formerly considered excessive in relation to probable returns, have become economic mineral prospects. The proton precession magnetometer offers the possibility of opening up new areas for successful magnetic prospecting.AN OUTLINE OF THE HISTORY OF MAGNETIC PROSPECTINGWhile an outline of the history of magnetic prospecting is not directly connected with the evaluation of a proton pre...

Jan 1, 1963

By R Salmon, C Jones

This paper examines the recent trend towards sustainability reporting and the application of the Global Reporting Initiative (GRI) æSustainability Reporting GuidelinesÆ. It also reviews reporting in the context of the Australian Minerals Industry Code for Environmental Management, as well as the status of public sustainability reporting globally in the minerals industry. The public reporting of environmental, health and safety, social/community and economic performance has evolved over the past two decades. Initially, separate and to some degree disparate documents were produced to report performance in each distinct area. In the early to mid 1980Æs some organisations had begun to report their environmental performance through some minor commentary in their annual financial reports or through ætokenisticÆ leaflets, often used as public relations exercises. Due to more media coverage and an elevated level of public scrutiny, organisations are no longer merely reporting their good performance, but also their bad and indifferent performance. In recent years these once separate environment, health and safety and community public reports have further evolved to become more integrated, reflecting organisations embarking on the reporting of their progress towards sustainable development. The primary factor in driving the evolution of sustainability reporting has been the increasing influence of stakeholders. Two groups of external stakeholders that have had a significant influence over public sustainability reporting in recent years have been non government organisations (NGOs) and socially responsible investment funds. Significant expenditure is involved in the preparation and publication of a sustainability report however many organisations do not appear to have examined in detail what they are really trying to achieve from their public reporting process. It is important to establish objectives for the public reporting process to achieve maximum benefits. Without a framework of public reporting objectives, the benefits of the reporting process to the organisation will not be recognised and the considerable expenditure involved will be increasingly difficult to justify. We believe that by focussing on the process rather than the document, significant benefits to the organisation can be gained. Indeed, with a proper framework of objectives and targets, the reporting process can be used as a vehicle to drive organisational change, implement management systems and improve performance. An idealised framework for a public sustainability reporting process sees the organisationÆs sustainability policies drive the entire process and determine the sustainability objectives. Specific targets are then set to realise those objectives. The targets will govern performance indicators that should be used to measure the success of target achievement and which will also define what data need to be collected. Evaluation is a key component of the reporting process to measure the success of target achievement and progress in realising objectives, as well as review the need for new targets to be set. The actual production of a public document is only one, albeit important, component of the overall reporting process. The challenges that lie ahead for sustainability reporting primarily relate to the integration of environmental, social and economic performance reporting as organisations integrate their approach to these areas. This will only happen as the culture of an organisation changes to not only accept the principles of sustainable development but to implement those principles in daily operations. The reporting process has the potential to drive that cultural change by communicating the organisationÆs sustainability objectives and setting challenging targets for their realisation. Public sustainability reporting will only achieve its maximum value when it forms an integral part of an organisationÆs sustainability management system and culture.

Jan 1, 2002

By D. S. Hines

The purchase of mechanical equipment for mines is not unlike the purchase of other materials or supplies in general principle, but on account of the major part such equipment plays in the operations, and of the fact that life and valuable property are at stake, the matter demands the most careful attention on the part of the purchaser. The problems and difficulties encountered are dealt with below in their sequence in the purchasing procedure. Requisiting Although it is quite a common practice to submit a tentative specification of requirements to recognized manufacturers of equipment- soliciting alternative propositions or recommendations for study in the selection of certain equipment-as a rule the first step in purchasing procedure is the requisition. Primarily, it is the form that carries to the purchasing department the record of equipment wanted. A full and complete description or specification, and accuracy of record, are the important points to be insisted on in a requisition. Too much attention cannot be given to this detail, as this is one of 'the most important phases of purchasing work. Incomplete information, either in specification or detail, leads to delay in handling the requisition, and, if not detected in the purchasing department, may mean receipt of material which cannot be used for the purpose intended. In addition to description of material or equipment to be ordered, the requisition should also show where or what the equipment is for, whether for operating or new work. If for capital account, the number of the authority for expenditure should be given for record and distribution purposes.

Jan 1, 1930

The Purification of Low-Grade Quartz Ore by Flotation and its Mechanism

Sep 13, 2010

The commercial application of electrolysis to zinc sulphate solutions for the production of metallic zinc is a development ·of the past twenty years. Earlier attempts failed to give satisfactory results, chiefly because certain harmful elements were either not recognised as being present in the solution, or, if recognised, suitable methods of removal had not been developed. The electrodeposition of zinc from zinc sulphate solution is extremely sensitive to the influence of a great many factors, all of which appear to be closely inter-related.Some of these factors tend to minimise the necessity for a high degree of purity of the solution, while other factors aggravate the harmful nature of certain impurities.The relationship existing betweBn the various factors in zinc electrolysis makes a general discussion of the injurious effect of impurities very difficult since, under one set of conditions a given concentration of an impurity may be of minor: importance, where its under another set of conditions the same concentration of that impurity may prove dangerous to successful electrolysis.

Jan 1, 1934

By C. Dixon

This paper is based on the assumption of some knowledge of the National Water Act. It will consider the question of how that Act fits in with: a) existing laws which overlap on the subject matter b) new laws either in draft or in the process of being compiled c) policies which will eventually find their provisions included in new legislation (e.g. minerals policy) d) international practices. The focus will be specifically on the interaction of legislation relating to water use and water pollution in the mining sector as well as the role of the Department of Water Affairs in mining matters. Hence the title of the presentation.

Jan 1, 1999

The Fraser Range is composed dominantly of basic pyroxene granulites derived from basalts, many of which appear to have been vesicular and pillowed. Acidic and basic garnet-bearing granulites are important in the west, and acidic granulites and narrow anorthosite layers are dominant in some regions east of the Fraser Range. An extensive flat-lying olivine gabbro sheet cuts the granulites, and in places has been converted to spineI-bearingmeta-gabbros and pyroxene granulites. The granulites of the Fraser Range (Proterozoic) are separated from the gneisses and schists of the goldfields regions (Archaean) by the Fraser Fault, over which there is a large gravity anomaly (gradient 20 milligals per mile). Some of the problems associated with the concentration of Cu, and Ni liberated from mineral lattices during metamorphism, and other principles of metal concentration in granulite terranes, are discussed. The recognition of vesicular and pillowed zones, even though highly metamorphosed, is of fundamental importance.

Jan 1, 1969

By Eero Pokki

The Päijänne Tunnel is being constructed to conduct raw water from Lake Päijänne to the Helsinki Metropolitan Area. The length of the tunnel will be 120 km and the cross-sectional area is 15.5 sq m. Excavation started in 1973 and will be completed in 1982. 94 km of the tunnel have been constructed from Lake Päijänne towards Helsinki. The construction has advanced according to plan, and due to Finland's hard bedrock there have not been any great surprises. When completed, the tunnel will meet the water requirements of the Helsinki Metropolitan Area for a long time in the future because, with a free fall of 36 m, 9.6 cu m/s of water can be conducted through the tunnel from Lake Päijänne to the Helsinki Area. With pumping it will be possible to obtain a flow of 15 cu m/s, although at first the discharge will only be 5 cu m/s. The tunnel was partly taken into service as early as March 1979 when it was possible to conduct water to the municipalities north of the Helsinki Area. It is already possible now to conduct water to Helsinki, too, but from the Korpimäki pumping station onwards it must be done through the River Vantaa, which is polluted. When the tunnel is completed in 1982, good quality water can be conducted from Lake Päijänne to the Helsinki Metropolitan Area through a continuous rock tunnel. The cost estimate in 1973 was $ 88 million while it is now $ 90 million notwithstanding high inflation. AREAS NEEDED FOR CONSTRUCTION The areas needed for construction were bought through voluntary deals. Areas of 4 - 5 hectares were bought along the tunnel line at about 5 km intervals. The excavation of access tunnels was started from these places, and the crushed rock from the main tunnel was also transported there. However, it was not necessary to buy the area

Jan 1, 1979

By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

By W. R. Leeder

"The Quintette coal property lies in the Rocky Mountain foothills of northeastern British Columbia (see Figure 1). Quintette and the adjacent Bullmoose property of Teck Corporation are soon to become the first commercial coal mines in the Peace River Coal Field, which is estir1ated to contain 10 billion tonnes of metallurgical coal reserves.Denison Mines Limited acquired the original Quintette coal licenses in 1969 and 1970. Exploration began soon after and the first feasibility study was conducted in 1975. Denison devoted the following six years to extensive planning and feasibility studies of the project. During this period, the provincial and federal governments also undertook studies to assess infrastructure requirements and economic viability of development in this part of the province. Many of the proposed mine sites such as Bullmoose and Quintette were at least 100 to 150 kilometres from the towns of Chetwynd and Dawson Creek, the nearest centres serviced by good highways and a railroad, and a complete network of services would have to be provided if such mines were to be developed. The overall project became known as the North East Coal Development.Concurrently with the feasibility studies, numerous technical and sales missions to Japan were made by representatives of Canadian industry and government, culminating in January 1981 with agreements for Quintette Coal Limited and Teck Corporation to supply a total of 115 million tonnes 8 million tonnes per year for 15 years of primarily metallurgical coal to the Japanese Steel Industry."

Jan 1, 1983

By Lam. E. K., J. W. Jarvi, B. P. Bharadwaj

"The Rabbit Lake Operation is located in Northern Saskatchewan on the western shore of Wollaston Lake approximately 800 km north of Saskatoon, Saskatchewan.The Operation is owned by a joint venture of Cameco Corporation and Uranerz Exploration and Mining Limited. Cameco is the operator.The Mill started production in June 1975 under the ownership of Gulf Minerals Canada Limited and over the past twenty years has increased the rated production capacity to over twice the original design.The Mill was originally designed to process 485,000 tonnes per year of ore with an annual production of 2.0 million kg of U308 (yellowcake). During the past ten years changes in ore sources and process modifications have led to increased milling capacity and production targets. The Mill has treated a total of 8.6 million tonnes of ore and produced over 40 million kg of U308 in the twenty year period, despite the shutdown and cutbacks in operating time since 1989.The 1995 tonnage throughput was 206,000 tonnes per year. Annual production though has risen to 3.6 million kg of yellowcake despite the departure from full-time to half-time operation in 1991 (7 up-7 down). The forecast for the coming years will see tonnage rising from 300,000 to 570,000 tonnes, production of 4.5 to 5.4 million kg of yellowcake and an anticipated return in the year 1998 to full time operation.This paper will give a brief history of the Mill and focus on the present flowsheet and recent improvements to the process."

Jan 1, 1996

By F Hancock

A rainfall simulator was developed to assist with hydrogeomorphic research into the stability of engineered landforms associated with rehabilitated uranium mines in the Top End of Australia. It can be used in rough terrain with slope gradients up to 30o. The rainfall simulator is modular, utilises upward jetting nozzles, has a multiple head arrangement and is capable of delivering rainfall intensities between 60 and 300 mmh-1 over areas up to 1000 m2 and could be easily modified for larger areas. Rainfall uniformity is commonly in excess of 80 per cent and the kinetic energy approaches that of natural rainfall (The modular design utilises an equilateral triangular array of rainfall stands, constructed from galvanised steel water pipes and flexible plastic hoses. Total construction costs are low. The water supply reservoir is mobile and easily constructed. An example of its use at Ranger Uranium Mine, investigating the effect of cover on rainsplash and rainwash dominated processes shows that vegetation cover is likely to reduce the erosion rate by these processes by at least four times below that experienced on bare areas.

Jan 1, 1997

By Belcher C. B

A procedure was required for the rapid determination of silicon in low-alloy irons and a suitable method used the formation and reduction of silicomolybdic acid at 50°C. The procedure gives results for elemental silicon and this enables the correct computation of oxidation requirements in basic oxygen steelmaking. The method could be useful in iron foundries which have not installed direct reading spectrometers.INTRODUCTIONOxygen steelmaking experiments required rapid determinations of 0,5-1,6 per cent silicon in iron (3-4 per cent C) within 10 min of sampling; a reproducibility better than ±0.03 per cent Si was desired. Only elemental silicon (Si°) is of interest as a fuel in basic oxygen steelmaking technology, and the proposed procedure determines exclusively this form of silicon. The method is described as it may prove useful to other workers although the interference study would be incomplete for some applications.The analysis of silicon in iron is frequently obtained using direct reading spectrometers, but for the proposed experiments the spectrometers could not be used because of the prohibitive distance from the furnace. It should be noted that spectrometers determine both the elemental silicon and that present as silicon dioxide in occluded slag and inclusions.The silicon content of iron and steel is determined in this laboratory by spectrophotometric measurement of a "molybdenum blue" colour. The reactions involved have been extensively investigated; Strickland (1952) showed that a...

Jan 1, 1965