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By J. G. A. Stevenson

"IntroductionDURING the past quarter of a century diamond drilling, in all its phases, has increased in Canada to a very impressive total of more than 10,000,000 feet annually. Since the art of diamond drilling became recognized, some seventy-five years ago, there has been considerable improvement in both equipment and technique. The steam-powered drill rig and the hand-set diamond bit are things of the past.The purpose of this paper is to review some drilling trends •and practices over the past few years. In the preparation of the paper, the author wishes to acknowledge kind assistance of Mr. J. D. Cumming, Dr. C. H. Hitchcock, Mr. Robert H. Quintal, and many others, including staff members of the Longyear organization.Figures provided by the Dominion Bureau of Statistics for the year 1954 show that Canadian production of metallic and non-metallic minerals and structural materials had a value of $1,454.2 million, excluding radioactive products for which figures are not available. Approximately 61 per cent of this valuation comprised production of nickel, copper, gold, coal, asbestos, zinc, lead, and iron. It is certain that diamond drilling played a major role in the discovery and development of the orebodies from which these minerals were obtained.After the surface examination of an ore deposit, diamond drilling will automatically follow, in order to determine structure, grade, and tonnage.Footage drilled by mining companies and contractors on mineral exploration and blast-hole work since 1945, as reported by the Do-minion Bureau of Statistics, is shown in Figure 1."

Jan 1, 1955

By George E. Aiken

Agglomeration developments in the iron ore industry of North America are closely related to shifting patterns in commercially acceptable ore grades and even the definition of iron ores. These relationships have occurred mainly during the last 20 years. Many of these changes are an outgrowth of events which involved the history of the Mesabi Range. Although magnetic taconites had been discovered in the Lake Superior area about 1870, they remained unvrorked in part for lack of concentration methods and a generally unfavorable economic climate. Some 20 years later the rich Mesabi hematites were found beginning the era of direct shipping ores which continued through World War II. These Lake Superior iron ores included reserves of an estimated three billion tons. Following World War II, decreasing ore grades and rising costs began to force the closing of many underground iron mines. The early 50's saw the beginning of the decline in direct shipping ores and a spurt in produc- tion of natural iron concentrates. However, the market for unprocessed concentrates began to decline in the early 60's as agglomerated products and foreign ore s began to dominate the U. S. market.

Jan 1, 1973

By Jeffrey J. Daniels

Advances in borehole geophysical research for mineral assaying, and remote detection of mineralization away from the borehole. Nuclear activation measurement research has provided accurate in situ assays of economic metals with neutron-gamma activation, using a high resolution intrinsic-germanium detector. Although nuclear activation analysis is the present "best-hope" for obtaining in situ assays for some elements, gamma-gamma and magnetic susceptibility measurements can provide accurate assays for lead-zinc and magnetite, respectively. Borehole optical spectroscopy and x-ray fluorescence are being investigated as possible in situ assaying techniques for some minerals. More laboratory and field calibration research is needed before nonlinear complex resistivity (NLCR) can be routinely used as a quantitative assaying tool. Field tests have shown that variations in the local geologic environment can affect the quantitative accuracy of assay values from downhole NLCR measurements. Deeply penetrating borehole geophysical methods are increasingly being used for mineral exploration as drilling costs and exploration have increased. Borehole electrical measurements have been shown to be useful for detecting conductive orebodies that are not interesected by a drillhole. Hole-to-surface resistivity, and surface-to-hole time-domain electromagnetics are demonstrated to be particularly effective for defining mineralized zones in a massive sulfide environment. Borehole gravity meters and three-component magnetometers have been developed and should prove useful for defining geologic anomalies away from the drillhole.

Jan 1, 1985

By Harrison R. Cooper

Approximately 40 concentrators throughout the world have successfully adopted computer control for flotation circuit operation since 1969. Successful use of flotation control, gaining up to 2% efficiencies, has largely derived from effective employment of on-stream slurry analyzers and integration of key measurement data through digital processors. Requirements for reliable measurement have also led to improved functional reliability in magnetic flow meters, pH, reagent feed, and other key elements. Methods used in computer control of flotation will be reviewed and variations in operating philosophies will be described with reference to the approaches taken to flotation automation.

Jan 1, 1979

By K. V. Konigsmann

"Concentrate dewatering operations have a significant influence on the economics of base metal beneficiation. The expenditures f or energy and labour per tonne of product are high. The relatively low efficiencies of standard techniques present inducements for process modifications. Development efforts at several Noranda concentrators led to process changes which improved productivity, namely, agitated pulp storage in large vessels, process automation and pressure filtration.IntroductionA program was initiated in 1968 with the aim of improving utilization of manpower and equipment in dewatering operations. The following considerations motivated us in this effort: Firstly, filters and dryers had traditionally been operated continuously and in step with grinding and flotation circuits. The demand for labour and equipment operating time was fixed and was not determined by the rate of concentrate production.Secondly, dewatering equipment had usually been designed to handle the concentrate tonnages which were produced when mill feed grades were high; therefore the equipment operated at less than capacity when treating ores of average metal content. The first goal was the separation of the flotation process from concentrate dewatering by development of a practical storage system for concentrate pulps . A second objective was the gradual introduction of dependable automatic controls. The steep increase in energy costs after 1973 added urgency to the search for dewatering processes which were highly energy efficient."

Jan 1, 1984

By Anthony T. Jones

Deep seabed mining requires technology to collect materials and transport them to the surface. An international patent search was conducted to define the state of the art in seabed mining technology. Over 350 patents were identified from 12 patent systems. The majority was from the United States, Japan, and the former USSR. Patent activity in this field peaked in 1983 when 34 patents were issued. Since 1984, on average 6 patents have been issued annually. The technology represents ten major classifications. With the exception of Deepsea Ventures, Kawasaki and International Nickel, it appears that much of the technology developed and tested in the 1970s by consortia active in seabed mining was never patented. Over the past two decades, identifiable trends in marine technology could influence seabed mining application such as more sophisticated communication systems, advances in hydraulic manipulators, improved computational technology in navigation, modeling of vessel ? ocean interactions, and improved materials. The most significant recent activity has been in European applications, which disclose remotely controlled subsea vehicles for mining diamonds.

Jan 1, 2001

By Alan Bauer

New developments in drilling, blasting and explosives in both open-pit and underground mining operations are discussed, as well as novel surface blasting techniques such as are used in tar sand mining.

Jan 1, 1978

By A. C. Lordi

Present industrial plant design is influenced by motivators beyond the usual powerful one, creativity, on which Consultants thrive. The respected, although annoying, ever-present Return on Invested Capital becomes even more significant with anticipated escalation. Government regulations are having an increasing influence as air and water protection, sound and electrical safety requirements must be met And more recently, the increasing cost and uncertain availability of energy sources are having a revolutionary affect on plant design. More than ever before, the Consulting Engineer is faced with requirements and restrictions which tax even the most original thinkers -- and the result is good. This paper includes a brief review of recent trends in Cement Plant Engineering Design.

Jan 1, 1975

By Arthur Grounds

Historical In the course of a paper which is necessarily limited in length, such as the present one, it is obviously impossible to describe in detail the history, development, and present position of coal preparation in Western Europe. Great Britain has been blessed with large deposits of excellent coal of nearly every type, ranging from the high-grade anthracites of South Wales, which are characterised by their very low ash and volatile con-tents, to the superb coking coals of South Wales and Durham -probably the finest in the world -with their low ash and sulphur contents, the latter constituent often well be-low l per cent. Gas coals abound in Lancashire and Yorkshire, while coals from the East Midlands, Northumberland, and Scotland are excellent for steam-raising and other industrial purposes. The excellent quality of these various coals has, in years gone by, ensured ready .sales abroad and it is not surprising, therefore; that methods of coal preparation were largely developed on the Continent in an endeavour to upgrade the inferior fuels found there, so that the prepared product could compete with British coals on the European market.

Jan 1, 1951

By S. K. Mishra

The history of the Australian coal industry is almost as old as the history of Australia after new settlement. The first cargo of coal was exported from Newcastle to India in 1799. Although coal has been mined in Australia for almost two centuries, there are indications that the first coal was processed in 1877 in the New-castle area, nearly a half-century after the first coal processing in Europe. Processing on any significant scale began only in 1944 at the Newcastle Steel Works. In Queensland, however, coal processing did not begin until the second quarter of this century. The well-known dramatic growth of mining and processing of Australian coal since the mid-sixties has primarily been due to the expansion of the export market in Japan and other Asian and European countries. Black coal occurs in most of the major sedimentary basins in Australia. The better known deposits of commercial importance are in Sydney, Bowen, Oakland and Gailiee Basins (Figure 1). Apart from Collie Basin in Western Australia, other coal deposits of the Arckinga Basin in South Australia, the Bonaparte Basin in Northern Territory and Tasmania Basin, Tasmania, are basically unexploited. Sydney Basin of New South Wales and Bowen Basin of Queensland remain the major producers of black coal in Australia.

Jan 1, 1985

By Lawrence Pelham

The demand or consumption of fluorspar has been somewhat taken for granted in recent years, except for the specific interest of those that produce, market, and/or consume the commodity. A tradition was established of thinking that as the steel and aluminum industry goes, so goes fluorspar. This is much less true today than in the past. The industry is becoming more dependent on chemical industries that feed primarily off hydrofluoric acid (HF) production. The Bureau of Mines recently published an assessment of world fluorspar reserves and resources that created a foundation of valuable data that can be used to monitor fluorspar availability. Celebrations were held this year commemorating the 100th anniversary of the isolation of fluorine. The United States and other countries continue to struggle with the controversy of ozone depletion and the effect of fluorocarbons on the atmosphere. The goals for the U.S. Government's strategic stockpile are being reevaluated. The market for fluorine chemicals is changing and diversifying, making it a challenge to assess and forecast fluorspar/fluorine demand. This paper reviews the recent past of fluorspar and helps set the stage for a more detailed assessment of this critical commodity.

Jan 1, 1986

By L. L. Newman

PUBLIC UTILITY GAS PRODUCTION IN 1802, William Murdock first used retort coal gas to light his house and the Boulton and Watt plant where he was employed. For the next three quarters of a century coal served as the principal raw material for the manufacture of city gas for general distribution. Coal continued to hold its predominant position for another half century after Prof. Thaddeus C. Lowe developed the first practical method of enriching water gas with cracked-oil vapors in an integrated operation. This position, however, was no longer maintained through the medium of direct carbonization of coal in retorts but as a result of using anthracite or coke as the generator fuel in carburretted water-gas machines. The early water-gas machines were extremely crude and the consumption of both oil and generator fuel was very high. However, the cost of installation was considerably lower than for any coal-gas system having the equivalent gas-making capacity, the labor involved was small, and the water-gas machine could be started up and shut down quickly. It thus proved very useful as standby equipment and in taking peak loads from the coal-gas plants. The flexibility of the water-gas machine, furthermore, made it possible to change the candlepower of the gas readily to suit the required conditions. Later, when calorific value replaced candlepower as the standard of gas quality, the water-gas machine was found to be equally flexible in keeping the city gas under complete and convenient control. No basic improvements were made in the Lowe carburetted water-gas process until 1898, when means were added to provide for regular reversals of the flow of steam through the fuel bed. By judicious proportioning of the quantities of up-run and down-run steam, it became possible for the operator to control the hardness and position of the clinker to a degree that previously had been unattainable. Also in 1898, the first by-product coke plant in America to supply city gas was built at Everett, Massachusetts. Later many other by-product plants, of greatly improved design and capacity, were built, but not primarily for city-gas production, chiefly because of the relatively high investment cost per unit of gas made. Cheaper plant construction has been the subject of serious study, and some progress is expected, but other factors, such as plant life,

Jan 1, 1953

By R. H. Nafziger

Owing to the growth of alloy steel production and its influence on tramp element levels when recycled, foundries have expressed concern regarding the quality of scrap used to prepare iron castings. Reliable and current information was unavailable on the amount of tramp elements contained in iron castings over time. Accordingly, the U.S. Bureau of Mines, in cooperation with the American Foundrymen's Society (AFS), analyzed cast iron samples from participating foundries throughout the United States on a quarterly basis to ascertain possible trends. Each sample was analyzed for 28 elements to determine if changes had occurred as a function of several input variables. This bulletin describes the research and presents analytical results and evaluations over a 5-3/4-year period from January 1981 to September 1986. Results show that iron casting compositions are changing with respect to a few tramp elements such as arsenic, cobalt, chromium, tin, and zinc over the period. Changes in charge compositions probably are responsible. Significant variations between zones also were observed with aluminum, arsenic, cobalt, chromium, copper, and manganese.

Jan 1, 1990

By D Yan, D Connelly

Beneficiation of magnetite is an integral part of the future of iron ore processing. Historically, the focus of Western Australian producers has been on exporting direct shipping ore (DSO) namely haematite. The future for new DSO resources is limited so companies are changing their emphasis into processing the very large, undeveloped magnetite ores in Western Australia (WA), using beneficiation to produce shippable magnetite concentrates. These magnetite resources require higher cost processing techniques such as fine grinding and beneficiation to produce saleable concentrates. This distinct difference, from the DSO ores, has led to the development of a number of new technologies. This paper reviews: the different techniques used for magnetite beneficiation and provides some case studies in the WA industry; the use of mineral liberation analysis (MLA) to describe the nature, grain size, occurrence and associations of the mineralisation;the consideration of coarse cobbing as a critical upgrading; the application of high pressure grinding rolls (HPGR) to save energy; how the field of magnetic separation has resulted in new machines with higher field strength (SLon Separators); ultra fine grinding requirements of magnetite concentrates; andthe application of reverse flotation to reduce silica in the concentrates.

Jan 1, 2009

By Ri McCrindle

"Analytical Chemistry is moving rapidly towards a concept where technicians have to do no more than press a button and print the result from an instrument that is a featureless ""black box"". In this environment we must ask how much traditional ''wet chemistry"" is still required for undergraduate students.Methods that can be fully automated will become increasingly important. An example of such a method is that of the slurry nebulisation and ICP-OES analysis of precious metal concentrate. Grinding the sample and adding Triton X100 as dispersant, complete analysis time is in the order of 90 min as apposed to the traditional Carius tube method which could take as long as 24 h. For most of the elements studied, the results using ""in-house"" reference material for calibration and as samples as well were within the 95% confidence level. Elements of low concentration in the sample (As, Bi and Se) were not within that level."

Jan 1, 2014

By K J. Kidd

There is general understanding of hoisting systems throughout the mining industry. However, the relative importance of the various parameters influencing hoist selection and utilization is not completely understood. In order to determine if these parameters can be identified and prioritized, data covering 613 hoist installations were compiled. The 613 installations represent hoisting systems in 30 countries on six continents. This study compares data to historical trends, correlates design parameters in an attempt to identify underlying selection criteria, and comments on the apparent trends in recent developments in hoist design.

Jan 1, 1998

By C. George Miller

"As the influence of governments has become more widely felt, the use of research techniques to analyze policy has increased. Mineral economics, as one of the foundations of mineral policy research, has grown accordingly. Policy research and analysis has been carried out within governments, university departments and the private sector. Each of these institutional environments has characteristics which influence the topics of study, the approach, the methodology and the output of the research. A brief survey of recent research activities provides illustrations of trends and developments occurring within this organizational framework.A radically different organization, the independent research institute, has begun to make an impact on policy research in recent years, and will have an increasing importance in the future. Combining certain features of the traditional research organizations, it nevertheless has important differences which are essential to its effective functioning. An overview of the formation, goals, organization and operation of one such institute is presented."

Jan 1, 1976

By Phillip Crowson

The annual surveys of corporate exploration expenditures carried out by Metals Economics Group (MEG) show that estimated total spending rose to a record $13.2 billion in 2008 ($14.4 billion including expenditure on uranium exploration). This compares with the previous peak of $5.2 billion in 1997. MEG does not adjust its figures for the effects of inflation but recognizes that the substantial increase in budgets of recent years has not been reflected in a proportionate rise in actual activity on the ground (MEG, 2009). In recent years, costs were boosted by rising prices of fuel and other inputs, and acute shortages of qualified staff and drilling rigs. The inflation rate for exploration substantially exceeded increases in general price levels as measured by national indices. Just how much exploration costs in-creased, however, is probably not widely appreciated. Figure 1 compares the MEG estimates of total annual dollar spending in Australia, Canada and the United States combined with their drilling activity, measured in meters drilled, as reported by national agencies. These three countries accounted for 39 percent of MEG?s estimate of total spending on minerals exploration in 2007 and 40 percent in 2008. Expenditure is shown both in money terms, as reported by MEG, and adjusted to real terms, with the U.S. implicit gross domestic product (GDP) price deflator. The comparison is of index numbers based on 2000 as 100. Comparisons for the individual countries are shown in Fig. 2 to 4. National figures for drilling activity and expenditures cover some minerals like iron ore, coal and industrial minerals (29 percent of Australian spending in 2007 to 2008 and 10 percent of Canadian in 2008) that are not included in the MEG estimates of spending. Such exploration has risen more than the total since 1997 so that the index of drilling activity in the figure may be overstated for recent years on a like for like basis with the MEG data. MEG only includes spending on uranium exploration in recent years whereas the national agencies include it throughout. Figures 5 and 6 com-pare national and MEG estimates for Australia and Canada. No comparable figures are available for the United States. The national estimates have been converted to U.S. dollars at the appropriate annual average exchange rates, and the Australian annual totals have been summed from the published quarterly data. Not only is spending cyclical, but so are unit costs. Australian and Canadian data show that total exploration spending per meter drilled rose by 2.5 to 3 times between 2001 and 2008. These rises may partly reflect increasingly complex drilling methods, and an increased share of assaying and testing in total exploration costs. In Canada, however, diamond drilling accounted for a lower footage of the total in 2005-2007 than in the preceding few years, and spending on exploration, as opposed to deposit appraisal, made up a higher proportion of the total. Figure 7 compares index numbers of exploration spending per meter drilled in U.S. dollars for Australia and Canada. These figures raise a number of questions. First, is the relationship between total expenditure and meters drilled in the three countries for which data are available typical of the global experience? Secondly, has there been a significant change in the make-up of exploration spending in recent years? The Canadian data do not suggest that there has been, but is Canada typical? Has drilling become less important relative to other exploration techniques, or is it just as important as ever in confirming the existence of viable ore deposits?

Jan 1, 2009

By W. A. STERLING

IN the opencut iron mines of the Mesabi Range in Minnesota, the trend in mining is in the development of mining equipment and mining methods which will move surface overburden and ore-bearing materials with less labor and at a cheaper cost. This is a must for most of the independent operators. Their reserves of direct-shipping ore are extremely small and their operations are being conducted in small, or intermediate pits, with a high stripping ratio in the outer fringes, or shore lines of older pits. and in ore bodies passing from direct shipping to the washing and the intermediate, or retreat ore state. The trend is toward deeper stripping, longer and steeper hauls, and the necessity of moving a total of from three to five or six tons of overburden and ore material for each ton of shipping-grade ore produced. This naturally calls for greater production, with larger shovels, or draglines. cheaper drilling and blasting costs through the drilling of larger-diameter blastholes, and cheaper haulage through the use of trucks of larger capacity and more extensive use of belt-conveyor systems. This trend is notable both in stripping and mining.

Jan 1, 1948

By Dennis Asmussen

The peatlands of the U.S. and Canadian parts of the Upper Great Lakes region have a long history of modest utilization in agriculture, forestry, horticulture, and as natural undisturbed areas. Only recently have they been assessed as potential sources of non-renewable or renewable energy. This new interest in peatlands, should current proposals be realized, might mean the commitment of millions of acres to energy production purposes. The magnitude alone of this potential utilization of peatland signals the possibility of substantial environmental disturbance, local resource shortages, resource use conflicts, and social and economic change. Peat- land resource managers in the region are just beginning to weigh the advantages and disadvantages of large-scale peatland utilization. The Minnesota Department of Natural Resources has made a considerable effort to study peat resource management issues and will shortly make recommendations to the state legislature regarding utilization alternatives. What follows is a general discussion of peatland utilization and management trends in the region with a focus on Minnesota and its peatland management efforts.

Jan 1, 1980