Search Documents

By George M. Fowler

DURING 1937 the subject of mining geology was probably given more attention and more mining geologists were usefully employed than at any previous time. Of the many contributing factors the most important were: (1) a higher degree of prosperity in many countries, (2) a. better understanding of geologic phenomena, and (3) the apparently diminishing reserves of several important minerals. Mining companies have come to look upon geology with a growing appreciation of its aid in the more effective exploration and exploitation of mineral deposits. Most of the larger and more active companies have one or more geologists permanently attached to their staffs and some have well organized and efficiently managed geological departments. Even the smaller companies, who feel they cannot afford to employ a geologist on a permanent basis, are seeking the advice of competent men in this field with increasing frequency. One of the most significant trends has been the growing tendency to base exploratory work on more thorough geologic studies instead of empirical "hunches,"on which so much off the work in the past has relied. Likewise, mining companies are apparently more willing to expend larger sums on the basis of geologic possibilities in a district.

Jan 1, 1938

By Sherwin F. Kelly

"THE TITLE I have chosen is certainly not one of those self-explanatory ones. I shall endeavour to make its significance clear during my remarks but, in the hope of minimizing that inevitable exodus which follows a good lunch such as this, I am going to withhold the final key to its meaning until the very last sentence of this talk.Some explanation is due at the beginning, however, so for those of you unfamiliar with Spanish I will explain that casa means house, or home. The casa about which I am going to talk necessitates a wide .and generous interpretation of the word, because I am using it to indicate principally that portion of the North American continent which is the home, in the western hemisphere, of British and American ideals of justice and freedom, the dignity of the individual and his right to exercise private initiative .and engage in private enterprise. In a wider sense, I am including the entire western hemisphere, which may yet stand as the last bulwark of political and industrial democracy.As for the treasures of which I am about to speak, may I remind you that there are no• material treasures but those derived from the earth, and they are derived by one of two processes, -mining and farming. These two fundamental industries are the basis, and the sole material basis, of our welfare, our wealth, our very existence. From farming, whether it be farming of the land. or farming of the sea, we obtain the food to keep us alive, healthy and able to work."

Jan 1, 1955

By Robert Glass Cleland

DURING the closing month of 1929, Walter Douglas found his health impaired by the strain of many difficult years of alternating prosperity and depression, and in April 1930 resigned the presidency of Phelps Dodge. Douglas was succeeded by Louis S. Cates. The choice broke a tradition that had been held inviolate for almost a hundred years. For the first time in its long history, the direction of the company's policies and operations was entrusted to a stranger without previous Phelps Dodge background, training, experience, or tradition. But the choice was wisely made. For a time at least, the path of Phelps Dodge was to run through rough and dubious ground, and no man in the United States was better qualified to blaze that trail than Louis Cates. After graduating from the Massachusetts Institute of Technology, Cates had served a rough and financially un- profitable apprenticeship at one of the century-old mining camps of Chihuahua, Mexico. Following his return to the United States and a brief interlude as assistant to the president of the National Steel and Wire Company, he had resumed his mining career, first as timekeeper, then as

Jan 1, 1952

By Y Xie, L O’Connor, S C. Dominy

Sheeted vein gold deposits are characterised by multiple subparallel veins and often free milling gold. Variability in gold grade and recovery parameters are enhanced by poorly designed sampling and test work protocols. Poor quality samples generally equate to an enhanced nugget effect. A sample can be described as being representative when it results in acceptable levels of bias and precision. Total sampling variability can be quantified by the relative sampling variance, which measures the total empirical sampling variance influenced by the heterogeneity of the lot being sampled under the current sampling / test work protocol. Effort should be made to minimise the relative sampling variance through Theory of Sampling (TOS) and quality assurance / quality control (QA/QC) application. This contribution reports on a case study that exemplifies how high-quality grade and recovery data can be gained from a well-designed and planned drilling, sampling and test work program, followed by bulk sampling. Results across historical resource drilling, geometallurgical drilling, laboratory assay / test work, geometallurgical modelling and a bulk sampling/pilot processing study are reconciled. A whole core, entire-sample test work protocol was used to acquire fit-for-purpose gold grade and recovery data for inclusion into a Pre Feasibility Study reported in accordance with the JORC Code.CITATION:Dominy, S C, O’Connor, L, Xie, Y and Glass, H J, 2017. Geometallurgical sampling protocol validation by bulk sampling in a sheeted vein gold deposit, in Proceedings Eighth World Conference on Sampling and Blending , pp 185–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Gary E. Slagel

The year was 1974. The event - the United States Congress was embroiled over what issues should be included in the proposed national surface mining law. The question - what should be done with underground mines? The leading bills ultimately addressed the environmental impacts associated with underground mines including provisions to protect the surface from subsidence impacts. Amid the fears that this subsidence language might discourage underground mining, sponsors of the bill were asked to explain the meaning of the provision that read "to prevent subsidence to the extent technologically and economically feasible." Was this an attempt to limit mining that caused planned and controlled subsidence? Former Deputy Director of the Office of Surface Mining, Dean Hunt, reviewed some of these historical events in a 1985 presentation before the Eastern Mineral Law Foundation. He reported that in 1974 Congressman Morris Udall took the floor to respond to these concerns expressed by other members of Congress and the industry. Mr. Hunt cited Congressman Udall's July 10, 1974 Congressional Record statement: "The House bill contemplates rules 'to prevent subsidence to the extent technologically and economically feasible.' The word prevent led to fears expressed by the Secretary of the Interior Morton, that the effect would be to outlaw longwall mining, with its obvious subsidence ... in fact the bill's sponsors consider longwall mining ecologically preferable and it and other methods of controlled subsidence are explicitly endorsed." Further, the report that accompanied the front-running bill, HR11500, provided the following clarification on the issue of subsidence prevention: "It is the intent of this section to provide the Secretary with the authority to require the design and conduct of underground mining methods to control subsidence to the extent technologically and economically feasible in order to protect the value and use of surface lands. Some of the measures available for subsidence control include: (1) leaving sufficient original mineral for support; (2) refraining from mining under certain areas---or (3) causing subsidence to occur at a predictable time and in a relatively uniform and predictable manner. This specifically allows for the uses of longwall and other mining techniques which completely remove the coal." It is clear from the preceding statements that Congress considered the removal of all the coal and causing subsidence in a predictable and uniform manner to be equal to or better than leaving support coal and causing no subsidence. While the actual provision in the bills talked of preventing subsidence, a subsequent exception made it clear that the real intent was to control it. This is evidenced in the specific planned subsidence language that appeared in the bills and ultimately in Section 516 (b) (1) of PL95-87, the Surface Mining Control and Reclamation Act. It reads: "...adopt measures...to prevent subsidence ... except in those instances where the mining technology used requires planned subsidence in a predictable and controlled manner..." In spite of this historic record that supports controlled subsidence, something has been lost in the implementation. The primary focus by many regulators over the past few years has been on the "prevent" aspect irrespective of mining method being used. This has appeared to change the original intent of Congress from one of controlling subsidence to one of minimizing damage. The objective of this report is to review some of the current regulatory issues that impede full extraction mining and offer some suggestions on possible ways to deal with these issues.

Jan 1, 1986

By D. D. Runnells

This study focused on the chemical reactions between uranium tailings fluids and cores of subjacent bedrock from the site of the Cotter Corporation uranium mill at Canon City, Colorado. Actual and synthetic tailings fluids were forced through cores of bedrock. The pH of the effluent solutions was the dominant control on the behavior of dissolved species in solution. The pH depended on the presence or absence of calcite cement in the rocks. Calcite neutralized acidic raffinates and caused the precipitation of iron, manganese, aluminum, and possibly uranium. Chloride, sulfate, and sodium were not retarded upon passage through the cores, and sulfate and chloride should be useful as tracers of escaping tailings fluids. Zinc, copper, cobalt, nickel, uranium, and vanadium exhibited high mobility under acidic conditions and were strongly retarded at elevated pH. Calcium was released due to dissolution of calcite and ion-exchange. Magnesium was not retarded in concentrated solutions, but showed moderate retardation in dilute fluids. Potassium and ammonium both showed early retardation followed by breakthrough and mobility. The behavior of molybdenum was strongly dependent on pH, with retardation at low pH and mobility at elevated pH. Selenium was highly mobile under all conditions. Selenium should be a better tracer than molybdenum for many situations. Precipitation of carnotite appears to control the solubility of uranium and, possibly, vanadium. With the exception of the precipitation of aluminum and silica, all reactions were rapid.

Jan 1, 1983

By Kenneth F. Whinery, John M. Campbell

Basically, the Buckley-Leverett theory involves two systems which are similar in nature but are differentiated by time. These systems may be described by the fractional flow and frontal advance equations which essentially characterize the mechanics of oil movement while being expelled from the reservoir. The fractional flow equation originally developed by Leverettl may be expressed in the more usable form The development of this equation is based on Darcy's law describing fluid flow through porous media and applies to the flow at only one point (it is a point function). For simplification, the fractional flow equation is written in the above form because the capillary forces always increase the fractional flow of the displacing phase regardless of the direction of flow or the displacing phase. If, for simplicity, the effects due to gravity and capillary pressure differences are neglected, the fraction of the displacing fluid, f, at any point in the flowing stream is related to the properties of the system by 1 Thus, it is seen that in the absence of capillary and gravitational effects, fd for a given sand and fluids varies only with saturation and pressure. The magnitude of the viscosity ratio, —a has an effective range (range of about 30) in the system where gas is displacing oil and a much smaller range for water displacing oil. In order to make the fractional flow equation more versatile, it is necessary to connect the fractional flow at a given point and saturation with time. This problem was approached by Buckley and Leverett" who developed the frontal advance equation, Eq. 3 states that the rate of advance of a plane that has a fixed saturation, Sd, is proportional to the change in composition of the flow stream caused by a small change in the saturation of the displacing fluid. It is, essentially, a transformation of a material balance equation representing the net rate of accumulation of the displacing phase within a homogeneous sand block. This accumulation is proportional to the difference between the rate at which the displacing fluid enters the sand and that at which it leaves. Eq. 3 describes the velocity with which a plane of constant displacing phase saturation advances through a porous system. Buckley and Leverett," Babson,' Kern," Welge, and others have adequately discussed the basic mechanism and application of the fractional flow and frontal advance equations. APPLICATIONS OF THE FRONTAL ADVANCE THEORY TO PETROLEUM RECOVERY Two general applications of the Buckley-Leverett frontal advance theory involve the system in which the oil is being displaced by an expanding gas cap overlying the oil zone and that in which the oil is being displaced by water. Displacement by Gas in the Presence of an Immobile Water Saturation A system in which gas is the displacing phase may be thought of as having two forces effecting the displacement process. These forces are the gravitational force and that force exerted by the displacing gas. The gravitational effects control the displacing efficiency of the gas. The gravitational effect will be less at higher rates of flow, thereby reducing the effectiveness of the displacement of the oil by the gas. The more efficient displacements occur at flow rates which are less than the gravity free fall rate. Capillary forces can be neglected without materially changing the magnitude of the gas saturation. The Mile Six pool is used herein to illustrate the calculating procedures in evaluating gas drive-gravity drainage field perfomlance. These calculations represent the determination of the gas-oil contact when the distribution of the hydrocarbon pore volume is considered. Two methods

By McKinnon R. L

Laboratory and field work on the use of wetting agents for suppression of colliery dust is described. Although the results were inconclusive they were not discouraging and further investigation is required. The use of certain wetting agents may constitute a healthhazard.INTRODUCTIONCoal dust presents explosion and health hazards to the coal mining industry. The problem of dust suppression is particularly acute where water alone is unsatisfactory for this purpose. The addition of a surface active agent (wetting agent) to the water should enable the dust particles to be more easily wetted and thus more easily prevented from entering and spreading through the mine atmosphere.Investigations into this effect carried out at The University of Sydney mainly under research grants from The Joint Coal Board (Dawson and Hargraves, 1955; Charlton and Curnow, 1957) are summarized, and information on the possible harmful effects of certain wetting agents is given.Twelve local manufacturers and five importers supplied 52 wetting agents in liquid, solid, powder, and paste form.The active material content varied from approximately 10 per cent to 100 per cent and the cost per pound from 8d. to 14/3.LABORATORY TESTINGPossible test methodsThree methods of laboratory testing were considered.1. The standard method for comparing wetting agents is the Draves test, used in the textile industry on cotton...

Jan 1, 1961

By George K. Schenck

INTRODUCTION Recent advances in high-pressure water jet technology can be effectively employed in mining and tunneling. The new equipment is based on available industrial hardware such as pumps, nozzles, and rotary swivels and seals, and is compatible with present mining and tunneling techniques. Principal advantages of water-jet assisted cutting relative to standard cutting are higher production rates, lower dust levels, and reduced fines. When used on rock and coal miners, water jets mean that relatively smaller and cheaper machines can be purchased. If properly applied, the combined effect is lower cost and significantly improved health and safety. While commercial use of high-pressure water blast cutting and extraction of rock (and concrete) already has a firm foothold in Europe, application of this new technique is just beginning in America. This paper begins with current American applications of high-pressure water jets for drills, for slotting and channeling machines, and then discusses the emerging technology for initiating rock failure in conjunction with drag bits on coal plows, continuous miners and boom-type miners (roadheaders). The focus of this paper is use of high-pressure water jets for cutting rock. High-pressure water jet cutting utilizes water above 70 MPa and currently reaches to 300 MPa and above. Some informatfon is included on low pressure "wethead" coal shearers and boom miners with water pressure to about 15 MPa.

Jan 1, 1983

By W. K. Connor, O&apos

The U.S. Bureau of Mines investigated the Sheep Creek prospect in the north-central Alaska Range to evaluate the Pb, Zn, Ag, and Sn resources. The studies included field investigations, mineralogical characterization, and concentration tests. Mineralization at Sheep Creek consists of disseminated, banded, and massive pyrite, sphalerite, and galena. Tin occurs as grains of cassiterite (Sn02) in the quartz-mica matrix and within pyrite and sphalerite grains, and Ag occurs in solid solution within the galena. Three bulk surface samples and two sets of core samples were collected at the Sheep Creek prospect for this study. Gravity concentration yielded products with up to 30 pct Sn, and the best result was a product that recovered 52 pct of the Sn at a grade of 22 pct Sn. Bulk sulfide flotation yielded products that recovered up to 89 pct of the Zn, 73 pct of the Pb, and 75 pct of the Ag, but grades were relatively low; selective flotation would significantly increase the grades.

Jan 1, 1989

By J. Leinart

As is readily apparent, the reliability of the early-stage costs estimated for any mining project are critical to the viability of that project. An estimate too high might leave a potentially profitable deposit undeveloped or worse yet, available to a competitor. One too low might waste investment dollars in a project not yet economically ripe. There are two aspects critical to any estimate: 1. The cost data used to represent the values of the wages, salaries, supplies, and equipment. 2. The design used to determine the engineering parameters upon which the above estimated values are based. Given that all of the information contained in Mining Cost Service is provided by suppliers, equipment manufacturers and mine operators, one wonders why there is any question as to the reliability of cost estimates developed using this information. Given that it is all actual (as opposed to statistically derived) data, where do the problems with estimate reliability lie and what is the impact of the data on that reliability? The following presents a series of analyses designed to assess the reliability of the cost estimating process. Both the actual cost data and the engineering parameters upon which they are based are examined in an attempt to quantify and understand the importance of each. While several sources of cost information are available (Means, Richardson, Primedia?s Equipment Watch, and individual suppliers and manufacturers), the following rely solely on data contained in InfoMine USA, Inc?s, Mining Cost Service and in its Sherpa Mine Cost Estimating Software.

Feb 27, 2013

By W. M. Deaton

The formation of gas hydrates in natural-gas pipe lines depends on temperature and pressure conditions in the lines as well as on the presence of condensed water. The operating pressure in a pipe line may be determined easily and usually is available from the records of operation, but the temperature seldom is known. In cooperation with the American Gas Association, the Bureau of Mines, in its investigation of gas hydrates, conducted a pipe-line-temperature survey and studied underground temperatures at depths at which pipe lines ordinarily are buried and the relationship of these temperatures to prevailing atmospheric conditions. A similar but mere limited study of this type was conducted by engineers of the Bureau of Mines a number of yours ago.4/ A summary of the earlier findings was included in a general report by the Bureau on the flew of natural gas through high-pressure transmission lines.5/ In the present study, data on temperature variations were obtained at several places widely separated geographically. This information should assist pipe-line engineers in designing and operating natural-gas pipe lines.

Jan 1, 1941

By Terry S. Cory

This report describes the results of a measurement program to determine the broad spectral characteristics of both differential and common mode noise on phone lines in three coal mines; and, signal attenuation spectral characteristics on the same broad basis over phone line strings with taps/branches. The frequency range used was baseband -1000 Hz for resolution bandwidth ranging from 100 Hz near baseband to 30 KHz near I MHz. The signal attenuation measurements were performed on all three "legs" of taps where possible and applicable. Results were obtained comparing shielded and unshielded phone lines In one mine. The results include an improved electromagnetic noise chart for coal mines showing variations with types of mines, topology, and location of noise sources; also, fundamental high-frequency limit on untreated phone lines in coal mines is identified

Jan 1, 1981

By J. S. Harington

Our purpose is to record and to explain the widely changing numbers of the huge total of black workers on the gold mines of South Africa over the century from 1896 to 1996. These men were recruited from up to twenty territories, and their contributions are examined. The major areas providing labour over this long period have been Lesotho, the former Transkei within South Africa and Mozambique. From 1989 to 1996, for instance, these three areas accounted for over sixty per cent of the total labour force (tlf). Our principal Figure 1 shows the tlf fluctuating through time to reach a peak of 480 000 in 1988. Irregular falls are also documented with the most serious in 1995 to 180 000. Based on this graph we consider the political, economic, sociological and historical reasons behind these changing employment opportunities. These have included external world-scale events such as war or depression, as well as internal changes of national economy and policy. We show the importance for numbers employed of the discovery of gold in the Orange Free State in 1946, the influence generally of the ?Winds of Change? and the firm maintenance by the State of law and order. Varying gold production costs and profitability against high tax rates, allied with increasing wages and a lack of development capital, have led in the last decade to employment falling by fifty per cent, despite an actually higher value of gold output. Finally, this analysis considers the role of the migrant labour system as it affects, and is affected by, conditions in the gold mining industry, with special reference to its less than humane consequences in the numerically dominant territories of Lesotho and Transkei.

Jan 1, 2004

By Gerald G. Griswold, Allan G. Provost

INTRODUCTION The Norad Expansion Project was located 10 miles southwest of Colorado Springs, Colorado, within Cheyenne Mountain. The expansion areas to be excavated would be adjacent to the existing underground Norad complex, which would remain in operation during the work on the expansion. The original complex had been constructed approximately eight years earlier and had been in full operation for approximately five years. Phase I, Excavation was awarded the Tiro Construction Corporation, a subsidiary of Harrison Western Corporation, Denver, Colorado, in the fall of 1970. Notice to Proceed was given to Tiro on 28 December 1970. The project owner was the U. S. Air Force, design was performed by the U. S. Corps of Engineers, Omaha District, who would also serve as the construction agency. [ ]

Jan 1, 1979

By Bassam Kattaa

"Abstract - A heavy mineral survey of beach and dune sands including geochemical analysis for trace elements was undertaken to evaluate the economic potential of the sands and to understand the nature and distribution of the heavy minerals relative to potential source rocks. Results indicate that heavy minerals are generally derived from outcropping volcanic rocks that comprise a proportion of the hinterland in the south part of our survey area. The most abundant minerals are magnetite and pyroxene. The morphologies of the heavy mineral grains are angular to subangular, suggesting that they were transported short distances from the source rocks. Factors controlling heavy mineral distributions include wave and wind action, proximity to provenance, the fluvial drainage network, and longshore currrents.The most economically important mineral is ilmenite. Zircon and rutile concentrations are relatively minor and thus have lower economic potential."

Jan 1, 2002

By Nathan C. Rockwood

THE title of this paper, I understand, was suggested by professional mining engineers as an opportunity for someone to pose problems rather than to offer solutions for them, but the paper will merely attempt to pose some of the production problems of the mineral aggregates industry in such manner as to create professional interest in their solution by the mining engineer, geologist, geochemist and the metallurgical engineer versed in mineral-dressing technique. DEFINITION OF MINERAL AGGREGATES "Mineral aggregates" may be defined as fragments of any rock or mineral used to supply bulk or volume or substance for a given purpose. For example, mineral aggregates are used in portland-cement concrete to provide bulk with the expenditure of the least feasible amount of cement binder. Mineral aggregates are used without portland cement or bituminous binder in highway and railway roadbeds to provide substance, to carry loads. Mineral aggregates are used in filters for water and sewage, to provide substance for the liquid to trickle through. These are only a few typical uses of mineral aggregates. For all these uses, strength, toughness, resistance to abrasion, and durability are usually prime requisites; so, while theoretically mineral aggregates may be of any mineral composition, what really is desired is a mineral composition as nearly inert under the conditions of use as anything of earthly origin can be. EXPLORATION AND POSSIBILITIES OF DEVELOPMENT The distribution of deposits of mineral aggregate is universal, since almost any part of the earth's crust can be used; even the top soil is sometimes used in stabilized surfacing for highways or airport runways. Nevertheless there is ample opportunity for exercise of the talents of the mining engineer and the geologist in finding the particular deposit that will be most economical to develop, keeping in mind such considerations as: (1) quality and mineralogical characteristics of the material; (2) size and permanency of the market; (3) final cost of opening and development of the deposit; (4) selection of location of plant; (5) methods and costs of distribution of the product in comparison with both present and possible future competition; (6) selection of the proper type of operating equipment; (7) estimation of probable waste products and their disposal. These are typical but there are other considerations also. Because profit margins are far smaller than in any comparable mining operation, it is all the more logical to assume that a higher degree of expert knowledge is desirable to make a success of a mineral-aggregates business. The industry has much engineering talent in its operating branch, but it lacks, to a considerable

Jan 1, 1943

U.S. Minerals Coordinating Council Advised. -The Critical Materials Act of 1981, H. R. 4281, introduced on July 27, would create a Council on Critical Materials in the White House Executive Office to oversee Federal materials programs involving $1 billion committed to research by 14 agencies, and to serve as the President's focal point to evaluate materials policy. It was introduced by Congressman Fuqua (D-Fla.) whose Committee on Science and Technology has over-sight over the implementation of P. L. 96-479, the National Materials and Minerals Policy, Research and Development Act of 1980. Bulgaria's Mineral Bank. -Recently Bulgaria established a mineral bank to facilitate receipt of foreign credits for exploiting Bulgaria's mineral raw materials. The bank has wide powers to enter into business arrangements with foreign creditors. Bulgaria's main interest in trading with the West is to import the technology for developing energy and mineral resources.

Jan 1, 1981

The Mineral Density Separator (MDS) was developed by Mintek to predict mineral separation in a plant, evaluate efficiencies and develop scale-up parameters. This study investigated the influence of particle size on the results of the MDS, the misplacement of material in the MDS and the possibility of replacing heavy liquid float and sink analyses of coal with MDS analyses. Six tests were done with coal of different size ranges. Each MDS layer was subjected to a float-sink analysis whereafter each float fraction was screened to determine the particle size distribution. The results indicated that MDS results represent float-sink analyses when compared to an ash curve. There is some misplacement in the different MDS layers, but this does not seem to influence the results negatively. Keywords Mineral density separator, sink-float analyses, heavy liquid analyses, washability curve

Jan 1, 2006

By S. W. Marcuson, P. J. Mackey

The Canadian non-ferrous mining and metallurgical industry has made great strides in environmental protection during the past half century. The path taken by the copper-nickel smelting industry in reaching today’s level is traced in this paper. Following the practice at early copper smelters in Wales and in the US, Canadian smelters originally used tall stacks to disperse furnace of-gases. This was the normal mode of operation and was accepted by society and by Government. Gradually, Government regulations required fixation of sulphur dioxide emissions and Canadian companies responded with significant technical developments to achieve this result. The initial development in Canada of the first new technologies such as the Cominco Flash Suspension Roaster and the Freeman Flash Smelting Process - both representing early versions of the modern established flash smelting technologies - and then later technologies such as the Inco Flash Smelting Process and the Noranda Process, both of which continue to this day, are discussed in this paper in terms of their contributions to the development of environmentally friendly plants. The evolution of these and other technologies is also discussed. Some comments regarding how the industry will face the future are also included.

Jan 1, 2015