Search Documents

By J. L. Fitch, B. G. Hurd

The presence of gypsum in samples subjected to standard core analysis introduces serious errors in the measurement of water saturation and porosity. The magnitude of these errors, depending upon the type of analysis procedure used, has been evaluated experimentally and theoretically. Water-saturated pore volumes determined by vacuum distillation or retort procedures may be too high by as much as 48 per cent of the volume of gypsum present. The maximum error in this value determined by Dean-Stark extraction with toluene is 36 per cent of the gypsum volume. If pore space is measured by a Boyle's law type porosimeter the maximum erorr due to gypsum is 38 per cent of the original gypsum volume present. The conscientious core analyst may eliminate the errors caused by gypsum by either of two methods. He may apply suitable corrections for the water of crystallization removed from gypsum, or take special precautions to prevent dehydration of gypsum during core cleaning and alzalysis procedures. These alternatives are discussed and methods for obtaining reliable core analysis data are proposed. Gypsum (CaSO4 . 2H2O) occurs as a common mineral in many of the world's sedimentary basins. In addition to its presence as primary bedded evaporitic deposits, it is often found as secondary replacement zones and pore-fillings in host rocks. That it may cause false indications in porosity, both on neutron logs and in standard core analysis, has been generally recognized. False porosity interpretations from neutron logs result because the chemically bound water in gypsum attenuates neutrons as effectively as free water. Errors in core analysis result when gypsum is dehydrated prior to or during the analysis. Vacuum retort procedures used by many laboratories to determine fluid saturation and porosity effect a complete removal of water of crystallization from gypsum. The crystal water, distilled and collected with free water from the sample, is counted as water-sat11rated pore space. Dehydration of gypsum results in a decrease in volume occupied by calcium sulfate and a corresponding increase in pore volume. Thus, if gypsum is dehydrated by sample cleaning and drying procedures, subsequent porosity measurements with gas expansion or compression instruments will be high. The qualitative effect of gypsum on porosity determinations by retort procedures was discussed in a recent article by Bynum and Koepl3. They concluded that since false porosity was interpreted as being water saturated, determinations of oil content were not affected. Others in the industry, however, have pointed out that porosity values are often used with values of water saturation determined independently, e.g., from electric resistivity logs in making reserve estimates. Values of water saturation calculated from the formation resistivity using the Archie equation, S4= are actually low if values of are high due to gypsum. In this case, false porosity values due to gypsum could cause serious errors in calculations of oil-in-place. This investigation was made to determine quantitatively the effect of gypsum on porosity values determined by different core analysis procedures. EXPERIMENTAL PROCEDURES Dehydration of Gypsum The extent and rate of removal of water of crystallization from gypsum under conditions encountered in core analysis procedures were studied. Taken for the experiments were three types of relatively pure, naturally occurring gypsum, viz. selenite, satin spar and massive gypsum. Although all samples probably contained trace chemical impurities, each type lost the theoretical amount of water upon complete dehydration. An automatic recording thermobalance, similar to one described by Mauer2, was used to obtain dehydration rate data for samples heated in dry air. Water

By D. L. Morgan, J. A. Butterfield

"Geological data, production trends and current projects underway suggest that enough molybdenum will be available from more diversified sources to meet the world's growing demands. The growth in molybdenum consumption has been primarily related to its beneficial effects as an alloying agent in steel. This rapid growth has been deliberately fostered by stable prices, adequate supply and application research. The molybdenum industry is now in a process of change which has been seen in several other metals, such as aluminum and nickel. As supply sources have become more diversified, the market has become more competitive. The recent drop in consumption has led to excess production capacity, accumulation of substantial producer inventories and increased market uncertainties. While consumption is expected to increase in the next two to three years, it will take some time to absorb the excess capacity and inventory. The increased proportion of by-product capacity indicates that prices may become more variable. Producer discipline will be required to prevent serious price erosion in times of surplus. Future prices may not continue to increase with inflation. For the longer term, several factors favour the increased consumption of molybdenum. Engineering requirements are becoming more severe and molybdenum alloys can help to meet these changing needs. In addition, consumers can rely on a large and increasing supply of molybdenum. A 7 per cent growth rate in consumption can probably be sustained through the next decade, but new applications and reasonably stable prices will be needed to make this possible."

Jan 1, 1972

New Mexico?s active coal mines have reclamation challenges that are being successfully resolved through the application of geomorphic grading methods. Soils and overburden material are often of poor quality, and annual precipitation is low. Revegetation on south and west aspect slopes often failed to persist. The New Mexico Mining and Minerals Division had therefore been encouraging topographic diversity on reclamation to improve water harvesting and reduce the percentage of south aspect slopes. Steeply dipping, multiple coal seams may be mined by open pit methods. Structurally-controlled trellis drainage patterns that exist premine have to be replaced with dendritic drainage patterns on reclamation where the overburden had been pulverized. Sodic spoil material is prone to differential settling and the creation of piping features in areas where runoff ponds, which may lead to downslope instability. In each of these scenarios, the approximation of natural drainage patterns on the reclamation has reduced erosion and sedimentation by creating shorter slopes with correct profiles, and by improving conditions for revegetation establishment.

Jan 1, 2010

By James Aston

A PROPER consideration of this subject is not confined to the technical channels of production and metallurgy. It concerns an industry, and should cover economic aspects which are of material importance in any program of development. The discussion may logically be treated under three subdivisions, as follows: (1) manufacture, (2) characteristics related to quality of material; (3) adaptability and exploitation of product. MANUFACTURE OF WROUGHT IRON The manufacture of wrought iron is the most ancient art of the ferrous metal industry. The eighty years or less of existence of processes identified with our modern "Age of Steel" is a relatively brief interval compared with the several thousand years associated with the production of wrought iron by man. From the primitive early methods of production, manufacture for many centuries followed the line of direct reduction. There were developments as experience was gained through the years; but man's needs for a strong, ductile, forgeable product were met by reducing the ore to metallic iron in a single-stage operation. Following the development several centuries ago of what has become our modern blast-furnace operation, manufacture of wrought iron was gradually transformed into a two-stage method of first producing cast iron and then refining this to the desired degree of forgeability; the forerunner in principle of today's scheme of manufacture of steel. The product retained the essential characteristics of highly refined base metal with iron-silicate slag incorporation, which were associated with the material resulting from direct reduction methods. Cort's invention of the puddling process in 1784 is a landmark in wrought-iron manufacture. It consisted essentially in adapting a coal-fired reverberatory furnace to the refining operation; thus lifting the industry out of the slough of

Jan 1, 1935

By Gordon R. Sima

This contract is concerned with feasibility studies, design and fabrication of a prototype hand-held test instrument and a machine-mounted test Instrument for measurement of electrical shock hazards of mining machines. This report presents the proposed and detailed design of the hand-held test instrument and the machine-mounted test instrument. Theory of operation of each instrument is discussed and includes the operating parameters.

Jan 1, 1976

By J. R. D. Gravel, D. A. Poland

"The induration of iron ore pellets has always utilized prefired pellets to protect the pallet cars from the environment of the induration furnace. This paper presents the process used to obtain superior upper sidewalls. These heat resistant castings are used on induration pallet cars, and their life improvements by as much as 400% is a significant step towards the reduction of the prefired (or hearth layer pellets.) The benefit to the industry in the removal of the hearth layer is improved overall productivity. IntroductionThe Iron Ore Company of Canada (IOC) operates with production facilities located in Labrador City, Newfoundland and Sept Iles, Quebec. It has recently been acquired by North Limited, an Australian based resource oriented company. Prior to its acquisition, IOC has examined several methods of operational cost reductions. One of these was an examination of indurrating pallets. Pallets are composed of numerous assemblies and sub-assemblies. The examination of the upper sidewalls began as an intent to increase the operational life of the component. The anticipated net effect was to be a reduction in the overall pallet maintenance cost. All of the components and assemblies have undergone a severe scrutiny. IOC has found that the success of the project has depended upon not only the technical competency of all parties involved, but also upon the ability to share risk, to be innovative, and to find a partner with whom the development can proceed without fear and yet with accountability. IOC has found in Cast Steel Products (CSP) such a partner in the field of pallet development. This paper will undertake to explore the progression into the arena of partnering between IOC and CSP. CSP and IOC met in the fall of 1994. The work of re-engineering the pallets began with an initial order for 36 pallets in March, 1995. The work on the upper sidewalls involved segregation of the effect of alloy development versus physical geometry development. The nature of partnering between the two companies allocated alloy development to IOC and physical geometry development to CSP, yet no advancements were made in either area without the close co-operation or the involvement of both partners."

Jan 1, 1999

By H. -F. Krausse

Roof failures in underground coal mines are related to the lithology and geologic structure of the roof. There are two distinct suites of roof rock above the Herrin (No. 6) Coal in Illinois, and each has distinctive patterns of structure and roof failure. In black shale-limestone roof areas, roof instability is correlated with thinning of limestone beds and presence of faults and clay dikes. In gray shale roof regions, the prime roof hazards are posed by rolls, shear bodies, and presence of coal or carbonaceous partings in the roof. Most structural features examined are believed to have formed during early stages of sediment diagenesis and compaction. Structural trends and lithologic patterns are strongly interdependent for this reason. In many cases geologic patterns are so complex and locally variable that prediction of roof stability far in advance of mining is difficult. The need for greater flexibility in roof control planning is apparent.

Jan 1, 1979

By S. Narra

Converting biomass into valuable fuel requires various preprocessing of the raw materials. Biomass densification is one of the conversion processes for its utilization. The aim of densification is to produce biomass pellets, which can withstand regular handling stresses and exhibit high densities with uniform size and shape. Physical properties, such as the particle size distribution after comminution is of highest importance for the binding mechanisms in the pelletisation process. Durability and strength of the pellets play an important role indicating the ability to withstand handling stresses. Particle size distributions of the cereal straws (Rye and Wheat) after specific comminution and liberation processes have been carried out with the help of three different image analysis (Microscope, Camsizer and Fibreshape). The durability of the pellets have been investigated as specified in the standards (ASAE standard S269.4) with a quadratic crate and the strength of the pellets with compression and tension testing machine (Zwick Roell type: ZMART.PRO). The particles size results showed differences in both length and width after different comminution processing. An exact comparison between the particle size analyses with the three different image analyses was not possible. The particle size distribution and the different comminution processes displayed influences on the durability and strength of the produced pellets. The particle size distribution displayed approximately 40 % of fines and 60 % of fibers. The particle size distribution displayed a direct relation to the durability of the pellets. Further durability and strength of the pellets displayed a good correlation.

Sep 1, 2012

By Warren A. Sheaffer

THE chief uses for copper are as a conductor of electricity and as the chief component in brasses and bronzes. For such uses, the copper must be of very high purity. H the impurities are zinc, iron, lead, arsenic, or antimony, they can be removed to a great extent by fire-refining. H, however, gold, silver, nickel, or cobalt are present, electrolytic refining is necessary. Electrolytic refining must be preceded by fire-refining and hence all impure copper must be fire-refined. The electrolytic refining of copper is most efficiently carried on when the impurities in the anodes are at a minimum. Some of the impurities tend to deposit with the copper at the cathode, while others remain in solution, decreasing the conductivity of the electrolyte and thus increasing the voltage necessary for refining. Since these dissolved impurities must be removed by continuous purifications, the amount of impurity in the anode copper should be reduced by furnace refining to some predetermined limit. Anode furnace operation aims to reduce these impurities to a minimum beyond which the cost of further furnace refining would exceed that of removing the remaining small amounts of impurities from the electrolyte. The anodes should have a fine-grain internal structure because any pieces of metal becoming detached from the anode during the electrolytic refining are inconvenient to remove from the cells and may cause short-circuits. Impurities tend to disrupt such a structure and thus form zones of weakness during corrosion. When the impurities are reduced to a satisfactory mini-mum, the anode, due to having a fine-grain structure, will corrode uniformly over the entire surface area exposed to the electrolyte. Oxides of the impurities may be volatile, in which case they pass off as flue gases, or they may form viscous slags having a lower specific gravity than molten copper, thus permitting their removal by skimming. Some impurities can be oxidized by introducing air into the bath. Due to the large solubility of oxygen in molten copper, oxygen is distributed uniformly throughout the bath and thus comes into intimate contact with all impurities. The oxides which are insoluble in molten. copper are removed either as flue gases or as slag.

Jan 1, 1942

By C Tickell

Achieving occupational health and environmental noise objectives is a major consideration in the planning or operational phase of resource development and industrial projects to meet the needs of the workforce and community and comply with legislative requirements. For material handling systems, ventilation plants, mobile equipment, process plants and fixed infrastructure, noise emissions need to be considered at the design phase. The preferred approach is to provide noise emission technical specifications, but in many cases this is not stipulated. An occupational noise requirement, such as ‘not to exceed 85 dBA at 1 m’, is often provided, but this will not achieve the required occupational or environmental noise objectives and may cause overly stringent requirements when they may not be needed. It should be noted that when developing the technical specification, measuring compliance needs to be taken into account as, in some cases, measuring may be very difficult or even not possible.This paper will discuss the requirements for providing an effective noise specification that ensures the environmental and occupational noise objectives are able to be achieved and that, once installed, compliance can be measured. It discusses planning such as when to set the objective, correlating the appropriate objectives for the environmental and occupational noise requirements, allowing for measurement tolerance, providing a suitable criteria and data format for the suppliers to respond to and methodology to measure compliance. Different phases of a project require different approaches to planning for noise management and these will be discussed in the paper. Examples from 35 years of industry experience will be included.CITATION:Tickell, C, 2016. Preparing effective specifications for occupational health and environmental noise objectives in mining project design and delivery, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 781–788 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Of the twelve known ore zones on the Sunro property, acquired by Cowichan Copper Co., only the "B" and "C" orebodies of the "River Zone" had been explored sufficiently to indicate the grade and tonnage. The "B" zone was selected for initial production. The portion of this orebody above the main adit level was developed for horizontal-ring, longhole mining. Ore from the stope would be scraped directly to the coarse ore bin. The lack of a suitable mill site on surface, as well as the 8,000-ft. tramming distance, led naturally to the installation ground. I N November, 1960, a lease was obtained by Co-wichan Copper Co. Ltd. (N.P.L.) from Sunro Mines Ltd., covering the main ore (River) zone of the Sunro property. A total of twelve zones had been located on the property. Nine of these lay within the leased area. With the exception of the "B" and "C" orebodies of the River Zone, there had been insufficient exploration for tonnage and grade calculations. Exploration by previous companies had

Jan 1, 1965

By Alan E. Renshaw

"This paper is a practical overview of ways to reduce cost in the design and operation of an Arctic mine. The economically important issues of the Arctic mine that will be addressed include: permafrost and the active zone in general terms; road building in and over permafrost; Arctic geotechnical mine design considerations; pit dewatering techniques in sub-zero temperatures; and blasting frozen materials with techniques to obtain optimal results. A final section on a few special topics conclude this paper.Although this paper primarily refers to near surface conditions more closely associated to an Arctic surface mine, many of the ideas and techniques contained in the paper also apply to the surface construction of an Arctic underground mine."

Jan 1, 1996

By E. P. Carman

1. DAVENPORT, S. J. Bibliography of Bureau of Mines Publications Dealing With Health and Safety in the Mineral and Allied Industries, 1910--46. Tech. Paper 705, 1948, 154 pp. 30 cents. 2. FJELDNER, A. C., FISHER, P. L., AND POLLOCK, M. B. Bibliography of Bureau of Mines Investigations of Coal and Its Products, 1940 to 1945. Tech. Paper 698, 1947, 53 pp. 15 cents. 3. GOOD, J. E., ABREU, ALVARO, AND FRASER, THOMAS. The Coal Industry of Brazil. Part 1. General Economy, Production, and Marketing. Tech. Paper 713, 1949, 38 pp. 20 cents.

Jan 1, 1954

By C. J. Hunter

Prior to the commissioning of the Sansu Sulphide Treatment Plant (STP), Ashanti Goldfields' treatment facilities were capable of producing some 700 000 ounces of gold per annum. Ore sources were underground refractory sulphides, surface oxides and old tailings dams. In order to increase the mines production to 1 million ounces per annum and to accommodate the change in ore sources as surface mining moved into fresh sulphides, a part of the strategy adopted was -the construction of a new sulphide treatment plant with a capacity to mill 2.2 million tonnes per annum and produce 400 000 ounces of gold. The STP has been designed, built and commissioned. and has been in operation since February 1994. The Plant boasts the world's largest Bio-oxidation facility which is capable of treating 790 tonnes of sulphide concentrate per day at a grade of 11.4% sulphur and is currently undergoing an expansion to increase its capacity to 1050 tonnes per day. The following sections describe the reasons for selecting the BioX® Process, the plant design, the commissioning experience and the plant performance to date.

Jan 1, 1996

By U. E. Brown

This papery describing the mining methods employed by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the United States. The Bunker Hill and Sullivan mines are situated in the western part of the Coeur d'Alene district at Kellogg, Shoshone County, Idaho. The mines were discovered during the summer of 1885 and except for two short periods of labor trouble, between 1890 and 1900, have been in continuous operation. About 575 men are employed at the mine. The production is about 1,400 tons of lead-silver ore per day. This is treated in the company's concentrator and smelter at Kellogg.

Jan 1, 1931

By Raymond B. Ladoo

Garnets are usually found well crystallized in the cubic system , the principal forms being rhombic dodecahedrons , tetragonal trisoctahedrons or combinations of the two , and hexoctahedrons . They also occur as rounded disseminated glassy grains and in compact massive , laminated or gramlar aggregates . They vary greatly in color , but the most common garnets , almandite and andradite , are most often found of a dark red or reddish brown color .

Apr 1, 1922

For some time the-mining industry has been criticised, completely unjustifiably, by certain people who style themselves conservationists but are actually preservationists. The criticism of the mining industry - and indeed all developmental industries has an emotional background and is not supported by facts. Some claims have been so disturbing that the Australian Mining Industry Council considered that the industry should do more in stating its position and attitude than has been done to date. It was therefore decided to request the Australasian Institute of Mining and Metallurgy (which is a technical organization) to join with it in presenting this seminar so that the subject could be examined on a scientific and factual basis, removed from the pressures of, emotion, and so that the media and the public could be presented with some basic factual data and, I trust, convinced of the soundness of the industry's attitude and policy. Many of the individuals in the mining and metallurgical industry are men who chose mining as a career because the location of mines gives an opportunity normally available only in the more remote areas. "These men do not want to see their countryside despoiled. '-The mining companies they manage and w rk for have accepted a responsibility to the environment which grows out of their close relationship with the earth.

Jan 1, 1971

By G. E. Viens, R. A. Campbell, G. N. Banks

A survey of the literature reveals wide differences in the procedures used in making iron ore pellets and in the properties of the pellets obtained. In this paper, the methods of production and the properties of pellets, as reported in the literature, are examined in an effort to determine what correlations exist between them. An attempt is also made to determine the levels of the properties of pellets which are considered acceptable and desirable in modern practice. M UCH has been written regarding the important changes which have been taking place recently in the iron ore industry. As the demand for ore has increased and the supply of direct-shipping ore has dwindled, tl1e problems associated with the utilization of lower grade ores ha\•e been intensely investigated and important advances in both beneficiation and agglomeration techniques have taken place. In particular, there has been a great deal of activity in connection with the pelletizing method of agglomeration. The superiority of pellets over raw ore has been demonstrated in blast furnace tests

Jan 1, 1962

By Zolfan F. Oszter

As exploration for new mineral deposits advances farther into the Canadian North, the more the design engineer is faced with the problems of cold weather conditions. This is especially true when designing belt conveyor systems for open-pit operations where the temperature in the winter may go to -40°F or below. Problems with the mechanical components and also with the belting will arise, which in turn may reduce the availability of the system. This paper outlines the problems encountered during cold weather operation and what precautionary measures must be taken into consideration in the design of equipment, as well as in the selection of materials, in order to ensure a system which will maintain production. THE conveying of ore and waste in the pit or to the processing plant poses problems during cold weather, when temperatures may drop to -4o?F or be-low. Troubles with the mechanical components, the belting or the supporting structure may arise, and this, in turn, will reduce the availability of the conveying system.

Jan 1, 1965

By W. D. Bonisteel

In 1976, Rio Algom Limited began the expansion of uranium production facilities at Elliot Lake. Quirke Mine was the only property in operation at the time, and plans were made to expand its milling capacity from 4,500 to 7,000 tons of ore per day. Following this expansion, other properties in the area will be reactivated to fulfill long-term contracts for uranium. As part of the expansion program, it was decided that in view of the escalating cost and impending shortage of energy, heat reclaim and conservation would be employed wherever practicable. In general terms, heat reclaim applications fall into three main classifications: ventilation, utility and process. Two of the ventilation applications and one process application will be described in some detail. Several other systems will be presented briefly as a matter of general interest. Some future possibilities will also be mentioned, together with their potential for economical heat recovery.

Jan 1, 1979