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By F. J. Susko

The U.S. Bureau of Mines is using Fourier-transform infrared (FT-IR) analysis to investigate the bonding mechanism which occurs during the dewatering of clay slurries. High molecular weight polymers are used as flocculating agents in these processes. This investigation presents the results of an FT-IR study of calcium-exchanged montmorillonite treated with polyacrylamide (PAM) and polyethylene oxide (PEO). Both thin film and attenuated total reflectance (ATR) spectroscopic techniques were employed to study this clay-polymer system~ Results suggest PAM is adsorbed to the clay via the nitrogen atom of the polymer. A water bridge is involved in the bonding between the clay and PE~. Evidence also suggests that PEO may be adsorbed directly onto the surface of the clay.

Jan 1, 1990

By J. Pang, S. Chander, A. Briceno

The mechanism of sulfur oxidation in pyrite is a function of the rate and driving force for oxidation. New evidence is presented to show that, at moderate potentials, a sulfur-rich hydrophobic layer is formed. Under ordinary conditions, the sulfur layer is covered with a layer of iron oxides, hydroxides, sulfate or oxy-sulfide ions. Pyrite is hydrophilic under these conditions. In the presence of iron-chelating agents or iron sequestering ions, an iron layer might not form. Under these conditions, the sulfur layer is exposed, and the pyrite might become hydrophobic. Stronger oxidizing conditions decompose the sulfur layer, thereby making the surface hydrophilic.

Jan 1, 1994

By Immo H. Redeker

Tile Asheville Minerals Research Laboratory is a member of the Engineering Research Department of North Carolina State University. The Laboratory is engaged mainly in applied nonmetallic mineral processing research to assist the North Carolina mining industry. A few out of state projects are handled at times. The Laboratory helped to bring the flotation process to North Carolina feldspar, spodumene, mica and phosphate producers and maintains versatile batch and pilot plant facilities at Asheville. It is of interest that North Carolina has now one of the newest and largest flotation plants at Lee Creek where Texas Gulf Sulphur Company produces 10,000 tons of phosphate concentrate per day, and one of the smallest flotation plants at Pittsburgh Plate Glass Company's fiberglass plant in Shelby, North Carolina where $50,000 per year of platinum-rhodium metal is reclaimed from wasted fiberglass furnace refractories in a tiny flotation operation of pilot plant size. The conservation of mineral resources through improved processing methods has been the object of most of the Laboratory's projects. This work has been extremely interesting and rewarding in many instances. Or, the example of projects for Kings Mountain Mica Company it will be demonstrated how waste could be reduced step by step from 20 tons of waste per ton of product to LO tons of product per ton of waste by improved processing methods. Brick, high grade potash feldspar, and silica sand are now produced from formerly wasted materials. AL this time Laboratory work sponsored by three feldspar companies, the State of North Carolina, and the U. S. Bureau of Mines, is aimed at reducing the amounts of feldspar tailings in the Spruce Pine area. Mineral dressing techniques are applied to reclaim saleable mineral products such as feldspar, mica quartz, and to make more uniform material for possible ceramic and other applications. Processes to produce new products such as sand-lime brick, and lightweight foamed autoclaved calcium silicate building products will be tested.

Jan 1, 1969

By William G. Pariseau

The purpose of this paper is to present a design procedure for the quantitative estimation of support load requirements in underground mines. Emphasis is upon the basic features of support behavior common to a large variety of support systems-bolts, timber sets, stope fill, steel arches, concrete liners and so forth. A strong reliance is placed upon fundamental principles and modern computing techniques for their quantitative implementation. Example problems illustrate the approach. Where artificial support is required, the ground in the vicinity of the face usually stands unsupported long enough for the support to be installed. At the time of installation, the load transferred to the support from the adjacent rock is essentially zero, although in some cases there may be an initial set load, for example, from timber blocking. With the passage of time and advance of the face, ground motion loads the supports. If the support system is properly designed, then the additional loading poses no threat to the safety and productivity of operations. If not, then difficulties may arise including high maintenance costs, hazardous work conditions and reduced productivity. Of course, over-design can be equally wasteful. Quantitative estimation of support loads is therefore essential to overall efficiency in mining.

Jan 1, 1975

By Mustafa Akser

Dwindling economic deposits of rutile (TiO2) prompted research on recovering it from secondary sources. One such resource is in Southwestern Turkey feldspar mining rejects that contain 5%-6% TiO2 mostly rutile. Previous studies could only upgrade the TiO2 to 36% TiO2 grade, claiming that the leftover flotation reagents on the surfaces of rutile and host minerals detrimentally affected upgrading of the rutile. As a potential remedy to this concern, a laboratory sample (from an operating feldspar mine in Milas, Turkey) was first caustic scrubbed, then air calcined at 400°C to evaporate the oily reagents. Subsequent physical separation of rutile included wet screening, gravity, magnetic, and electrostatic separation technologies. Such processes indeed improved the grade of the rutile concentrate up to 83 % TiO2 Low recovery of the TiO2 (<20%), was attributed to lack of full liberation of rutile, even at 125x44 micron range; interference with impurity minerals such as sphene and zircon; and simply the process inefficiency in upgrading the fine grains through conventional separation technologies for heavy minerals.

Jan 1, 1999

By G. J. Gersbach

The Robe River Iron Ore Project began in 1962 when Cliffs International acquired mining leases in Western Australia&apos;s Pilbara Region. Initial reserves were proven and bulk ore samples sent to the U.S.A. for pilot plant testwork. Cliffs Western Australian Mining Company Pty. Limited (30%) manages the project in joint venture with Mitsui Iron Ore Development Pty. Limited (30%), Robe River Limited (35%) and Cape Lambert Iron Associates (5%).

Jan 1, 1983

By Kanaan Hanna, Mir Heydari, Dipack Sengupta, Gordon B. French

This article concludes a two-part series on the safety, technology, and economic impact of eliminating safety fuse from metal and nonmetal mines. Discussed are the consequences of fuse abolishment, the technical feasibility of changing to an alternative system, and an economic analysis of initiation systems. Last month, part one (ME, pages 31-35) described current use of initiation systems, incidence of accidents, and consumption values for safety fuse and other initiation systems. Consequences of Fuse Abolishment Cap and Fuse Manufacturers Two major safety fuse manufacturers, Ensign Bickford and Apache Powder Co., share the US fuse market. Marketing of Ensign Bickford safety fuse is done by Dupont. Dupont manufactures electric caps as a main product and recently introduced a new nonelectric initiation system (Detaline). Therefore, Dupont would be only slightly affected by the elimination of safety fuse from metal and nonmetal mining. Ensign Bickford, though a larger manufacturer of fuse, does not appear to emphasize the safety fuse market. In fact, safety fuse sales represent only about 10% of Ensign Bickford&apos;s total sales volume. Ensign Bickford is strongly pushing its Nonel product. It appears, therefore, that the elimination of safety fuse would have a limited effect on Ensign Bickford, and could ultimately be to the company&apos;s advantage. Apache Powder Co., however, would be seriously affected if safety fuse was eliminated. Safety fuse, although not its only product, constitutes a major source of revenue for the company. It currently does not manufacture a substitute product. Apache Powder Co.&apos;s manager agrees that prohibiting the use of safety fuse would result in a greater market share of initiators for Ensign Bickford. Hercules could also benefit from the prohibition of safety fuse. Metal and Nonmetal Mining Industry According to an explosive company contact, elimination of safety fuse by a mandatory regulation would force some of the small, marginal mines out of business. Another powder company representative believes that eliminating safety fuse will result in uneasy situations for small operators not familiar with other techniques. These operators try to minimize the costs and traditionally like safety fuse. He believes that insufficient proof exists to substantiate the overall safety increase if the fuse is eliminated. Fuse manufacturers and distributors disagree, then, about the impact of safety fuse elimination. However, they tend to agree on some important points: • Safety fuse can be a safe method if applied properly. • Electric blasting can be dangerous due to stray currents, and may have higher misfire rates than safety fuse. • It is very difficult to compare the rate of misfires and partial round failures for different systems. This is due simply to the nonavailability of such data. In many cases, the misfires are not even reported to the shift boss, as required by regulations. • Safety fuse has high acceptance in certain applications, such as a face where Nonel or detonating cord are used, or in open-pit blasting. • The safety fuse industry appears to be phasing out on its own. It is expected that the fate of the safety fuse market will be similar to that of black powder. An investigation by Nitro Noble of Sweden "clearly states that the diminishing use of safety fuse has considerably reduced the accidents in Swedish mines." Mine Data Acquisition and Analysis As a part of the study effort, visits were arranged to 24 metal and nonmetal mines. In most cases, underground visits were accomplished. At least one drilling and loading operation was witnessed. The mines were grouped into four mining areas: Wyoming, Montana, Idaho; western Colorado and eastern Utah; Missouri; and southern Arizona. Of all mines visted, the safety fuse system was used in 11 mines, electrical system in seven, Nonel in five, and the Hercudet system in one surface mine. At each mine, the manager, foreman, and blasting crew were interviewed for information and opinions. Besides informal discussions with mine officials, a questionnaire was also filled out for each mine. Due to the extensive length of the information gathered, these data are not presented here.

Jan 2, 1984

By G. W. Mannard

The large massive sulphide deposits present a formidable challenge to the economic geologist. They represent such huge concentrations of iron, sulphur, base metals and precious metals that it is difficult to conceive how they were derived from the crust or mantle of the Earth. The problem of the origin of massive sulphide deposits has generated a geological controversy which has lasted two hundred years and shows no sign of abating. The economic incentive to solve this problem is great, as the massive sulphide bodies are the moat important source of the world&apos;s zinc, lead, and silver, as well as yielding large amounts of copper and gold. Using the criteria of abundance, size, age distribution and gross value of contained metals, the predominant sub-group of the massive sulphide deposits is that which comprises the crudely conformable pyritic (or pyrrhotitic) deposits which occur in stratified volcanic and sedimentary rocks or their metamorphosed equivalents. Examples of this sub-group are: the Buchans, Bathurst, Noranda, Kidd Creek, Flin Plon and Sullivan deposits of Canada; the Mt. Isa and Broken Hill orebodies of Australia; the Cyprus, Rio Tinto, Meggen and Rammelsberg deposits of Europe; Ducktown and the United Verde in United States; and the Kuroko deposits of Japan.

Jan 1, 1973

By Pierre J. Goossens

Since Guild 1 and Snelgrove 2 attracted our attention to the relationships between certain endogenic ore deposits and plate boundaries, an abundant flow of papers appeared in the metallogenic literature concerned with this problem and its application to mineral exploration. Some of the papers only speculate with the formation of specific type of ore deposit 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Other papers are more concerned with genetic and structural relationships between plate tectonics and mineralization 13, 14, 15, 16, 17, 18, 19, 20 They are philosophical, in that they are generalized and refer to no specific area. Yet it is true that a large part of the world mineral potential is concentrated at the convergence of oceanic and continental plates, for example, around the Pacific. Therefore, the interaction of two plates by either subduction, obduction or slippage likely has an important role for the genesis and/or the (structural) control of these "orogenic" ore deposits. If subduction is the driving mechanism for the generation of igneous rocks 21, 22 and endogenic ore deposits 18, volcanic activity and the nature of volcanic products certainly are the major geologic processes and events to be tested. Fonteilles 23 and Alsac 24 have already emphasized the important relationship between mineralization and the talc-alkaline affinity of the volcanics. The Andean orogen is one of the best areas for testing such genetic relationships. Rich and varied endogenic and volcanogenic ore deposits occur there and plate interaction is still active.

Jan 1, 1975

By Richard J. Lewandowski

Corrosion and product contamination have been difficult problems for extractive metallurgy industries in the U.S. because of the highly active chemicals used. During the past twelve years, other industries, particularly the chemical and paper segments, began to combat this problem with some degree of success using newer materials of construction, including reinforced plastics. These materials are made by combining a corrosion resistant thermosetting resin with a glass fiber reinforcing material and are used to con¬struct hoods, stacks, blowers, tanks, towers, pipe, and equipment of the most complex configurations. For service in contact with aggressive chemicals, the equipment is most often fabricated with the bisphenol-A fumarate polyester resins because of their resistance to corrosive attack. Data from both laboratory work and case histories of field applications are presented-for many common chemicals found in extractive processes. Information is also presented concerning design standards and recommended construction procedures

Jan 1, 1970

By A. G. Fonseca

The effects of coal cleaning, coal combustion and flue gas particulate removal systems on the partitioning of 12 trace elements were investigated. This study was prepared to help document the fate of trace elements in modern coal preparation plants and coal-fired utility boilers. The coal cleaning data were obtained from several coal preparation plant operations. The CONSOL 1. 5 MM Btu/hr pilot combustion and electrostatic precipitator (particulate removal system) test facility was used to develop the combustion systems data. A comparison with the very limited amount of published data from utility boilers is presented.

Jan 1, 1993

By C. Anastasiadis

The wettability of sandstone was investigated using the technique of dielectric spectroscopy in the frequency interval 1kHz-1MHz. The natural wetness of the material was modified to get two different sets of samples, one with sea-water wetness and the other with crude oil wetness. Measurements showed that the electric responses of water-wet and crude oil-wet samples were markedly different beside the fact that the dielectric response of both groups of samples obeys a general fractional power law. The dispersivity, of the complex permittivity component that expresses the material loss with respect to the electric field was found to be the most suitable parameter to check the wettability of the samples.

Jan 1, 2005

By M. Michael, A. Felber

"Mining activities, especially underground mining operations, create great demands on utilized haulage means which cover a variety of different horizontal and vertical distances. In the course of the continuous optimization of the haulage process, the application of textile machine elements, in particular synthetic fiber ropes, offers new opportunities. Therefore the current level of knowledge needs to be improved based on extensive analyses. For the estimation of the scope of these analyses, different fields of application and occurring environmental influences which have an impact on synthetic fiber ropes during their use in underground mining have to be evaluated. The Chair Underground Mining Methods of the TU Bergakademie Freiberg works on a scientific project concerning the use of synthetic fiber ropes in underground mining operations. This paper focuses on the potential application of synthetic fiber ropes in haulage systems in underground mining and exposes critical influences as an outcome of the working environment. These first investigations are the basis for the development of an appropriate experimental series. SYNTHETIC FIBER ROPES FOR UNDERGROUND MINING OPERATIONS The main idea is to optimize underground haulage means to develop even more economic systems. The new and lightweight design of single machine elements seems to be the first step to accomplish this goal. An example is the lightweight design of shaft hoisting ropes. The commonly used steel wire ropes are very heavy and are endangered to snap due to their own weight when reaching a distinguishing length. Thus they may not or only conditionally be used for deep mining operations utilizing shaft haulage. Ropes made of high-tech synthetic fibers weigh only an eighth of steel wire ropes while displaying the same tensile strength. This relation is shown in Figure 1, based on the comparison of fiber strength and density. This could offer new opportunities for deep mining operations, which are anticipated by many mining companies. /1/"

Jan 1, 2015

By D. Greene

Close integration of mine planning and operation is a long-sought goal. Success is achieved in varying degrees depending upon mine complexity, size, and sophistication, but too often is more limited than desired. Despite tremendous strides in the development of computer-aided mine planning, digital plans usually must still be converted to error-prone paper maps and physical ground surveys for actual excavation and reclamation. However, advances in GPS, operator displays, and mobile computers now enable equipment operators to work directly from on-board digital plans. CAES offers reduced survey costs, faster field transition time and improved excavation accuracy coupled with faster, more informed decision making regarding key mining operations.

Jan 1, 1997

By J. D. Morgan

The US economy continued to grow steadily in 1988, reaching an annual rate of $5 trillion in the last quarter (US trillion = 1012). The value of domestically processed mineral-based materi¬als rose 20% to $300 billion (US billion 109). The value of metals produced from US ores rose 40% to more than $10 billion, industrial minerals rose 6%&apos; to $20 billion, and recycled scrap more than doubled to $10 billion. Increasing economic activity stimulated metal prices. Yearly lows and highs were 95 cents and $1.68 for copper, 52 cents, and $1.30 for aluminum, 34 cents and 42 cents for lead, and 43 cents and 75 cents for zinc. A number of mining and metal companies experienced significantly increased profitability. Consumer demand strongly affects mining because the US economy is relatively saturated with long-lived products. Consumer, mortgage, and Federal debt continued to rise. About 246 million US citizens already possess 170 million licensed motor vehicles and 100 million dwelling units. New car production remained at the 1987 level of 7.1 million units. Truck and bus production, however, rose 7% to 4.1 million units. New housing starts fell 7% to 1.5 million units. Imports supplied a significant proportion of total US consumption of several important mineral materials. By year-end, imports of crude and refined petroleum exceeded domestic crude oil production. Such imports cost $42 billion. Imports of nonfuel mineral-based materials were valued at $44 billion and exports at $35 billion. The US and Canada-the world&apos;s two largest trading partners-consummated a historic free trade agreement. In February, President Reagan transferred responsibility for stockpiling strategic and critical materials to the Secretary of Defense. And, in July, the GSA group that bought, stored, rotated, and sold stockpiled materials was transferred to the Defense Department&apos;s Defense Logistics Agency. Concern about apartheid in South Africa continued, resulting in increasing attention to chromium, manganese, platinum-group metals, cobalt, vanadium, and gold. The Defense Production Act, authorizing priorities and allocations, supply expansions, voluntary agreements, and the National Defense Executive Reserve, was amended to include provisions for averting harm to national security from foreign takeovers. The DPAct, in effect through September 1989, is now up for further extension. Under the Act, the US Bureau of Mines maintains the Emergency Minerals Administration. During the year, consultations were held with Canada to strengthen the North American Defense Industrial Base. Coal production, 60% from open pits, rose 5% to 870 Mt (960 million st). Nearly four-fifths was burned to generate 57% of US electricity. Exports included 56 Mt (62 million st) of metallur- gical coal and 29 Mt (32 million st) of steam coal, with a total value of $4 billion. Domestic petroleum produc¬tion fell 2% to 574 hm3 (3.6 billion bbl). Uranium mining, including recovery from phosphates, was unchanged at 5.9 kt (6500 st). Nonfuel minerals Major metals Raw steel production-a major con¬sumer of many minerals-rose 14% to 92 Mt (102 million st). Domestic iron ore production rose 25% to 59 Mt (65 million st), about 96% pelletized. Net imports rose 37% to 16 Mt (18 million st). Raw steelmaking capacity of 102 Mt (112 million st) was unchanged. Voluntary Restraint Agreements with 21 steel exporting nations limited im¬port penetration to about 20% of the domestic market. Domestic producers of bulk ferroal¬loys of chromium, manganese, and sili¬con operated at about 75% of capacity. The US mined no manganese or chro-

Jan 1, 1989

By David A. Holmes

After a century of variable government-supplied housing on their cold, windswept lands, and facing extremely limited natural resources and no timber, the Standing Rock Sioux Tribe has launched a study into alternative housing approaches for their people. Considering that they have little more than the soil and limited river aggregates under their feet, the Tribe has elected to consider adobe and earthen-wall construction. Earthen construction is no stranger to the Sioux lands. Smaller tribes, including the Mandan, Arikira, and Hidatsa, lived here among the Sioux in earthlodges for centuries. Such earthlodge structures were not unlike the Southwestern jacal style-a framework of upright branches and branches covered with mud-employed by the Anasazi about A.D. 700-900. Indeed, the Sioux people themselves evolved from earlier earthlodge dwellers. Indigenous peoples in New Mexico, Arizona, and neighboring Mexico have used earthen-wall housing for many centuries, reinforcing Sioux observations that this is today an earth-friendly, cost-effective, and practical approach. The Cheyenne River and Pine Ridge Sioux Reservations also recently have conducted studies on earthen- wall construction. This paper describes the search for and evaluation of potential raw-material resources for earthen-wall/adobe construction on the Standing Rock Reservation in North and South Dakota. Significant resources of clay/silt materials (8 million tons in the Striped Cloud clay bed) suitable as adobe binders and sand-and-gravel aggregate (2.5 million tons) that could support earthen/adobe construction have been identified throughout the Fort Yates Flat area on the Reservation. Also addressed is how adobe and rammed-earth construction could add to the diversity of reservation construction and address future Tribal housing and other building needs.

Jan 1, 1999

By S. K. Sharma

The Bureau of Mines&apos; Tuscaloosa Research Center is conducting research to develop a basic understanding of solid-liquid separation in order to improve the dewatering of fine particle slurries. In the present investigation capillary suction time (CST) of kaolin slurries was determined. The average specific resistance of the cake was also determined by fitting the CST data to the theoretical equations used in this paper. The experimental data were analyzed by a powerful computer-based method, chemometrics, that uses statistical techniques to remove error and to find the number of physically significant factors contributing to the data. Results showed that two significant factors explain the CST data.

Jan 1, 1991

By Richard E. Barrett

The relationship between coal characteristics and power plant performance has become a matter of increasing interest to utilities. This relationship can affect the value of coals, decisions as to coal washing, setting penalties for delivery of coal that fails to meet specifications, and justifying buying better coals (at higher costs) before public utility commissions. The study described in this paper was directed to identifying how coal characteristics impact on boilers and related coal and gas handling systems. TVA data for the period 1962-1980 was the basis for the study. Models were developed for boiler efficiency, boiler availability, and maintenance costs as a function of such coal characteristics as ash, sulfur, and moisture content and boiler age. Boiler load and maintenance efforts were considered as variables in some of the models, but were found not to be statistically significant. Although the results of this study are strictly applicable to only the TVA system, they can serve as guides or first approximations for other utilities.

Jan 1, 1983

By Tae-kyeong Yeu, Cheon-Hong Min, Hyung-woo Kim, Sup Hong, Minuk Lee, Chang-Ho Lee

This paper concerns the optimum arrangement of the buoyancy module, which is used for stable dynamic motion and structure stability of the marine flexible riser. The main method of this study is simulation-based design using Genetic Algorithm (G.A) for optimum design and Multi-body dynamic for simulation. The marine riser connects the vessel and the seabed-tracked vehicle. The motion of the riser affects the motion of the vessel and the vehicle. In this study, a marine riser of the deep-seabed integrated mining system (Figure 1) is used. This riser has a strong effect on efficient transfer of minerals. So, the buoyancy module must be equipped to supplement problems of the structure stability and the dynamic motion. Positions and quantities of the equipping buoyancy modules are determined by the at sea experiment (Figure 2). But this method is not easy because the actual sea experiment is expensive, time-consuming and dangerous (Figure 3). Thus, the position and quantity must be determined by simulation-based design. The dynamic analysis models of the riser and the buoyancy module were built in the commercial software DAFUL. In the marine environment, factors affecting behavior are current, drag force, etc.

Sep 1, 2014

By Bela Koman

Abstract - A shiploading terminal near Punta Arenas, the southernmost city of the world (lat. 53°-10&apos;S, long. 70°-54&apos; W) is described. Strong winds, choppy seas, frequent gales, rain, and snow make it difficult to load ships at an offshore berth in this area. Detailed site investigations, including a wind-recording program, supplied sufficient information for the analysis of operating conditions. The weather pattern of the entire region, including the predictability of gales, was utilized in the analysis. The results showed that a bulk loading terminal at this location is feasible, provided that the design takes into consideration the specific problems of the site. The final layout shows a terminal that can be approached from several different directions, depending on the direction of the wind. The mooring system is arranged to allow alter- native ways of attaching and casting off mooring lines and executing docking and departing maneuvers. The berth is supported on piles and contains the minimum of structures, relying on a slewing shiploader to reach the ship in any position, with only limited fore and aft shifting of the vessel for loading the extreme hatches. Results of wind recording, statistical analysis of wind and wave data, operating criteria, and the results of berth availability analysis are included in the paper.

Jan 1, 1987