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By H. Hejny

"The mine of the future will exploit mineral raw materials at greater depths than today, requiring completely different approaches compared to today’s deep mines, in order to get mineral rights. Only these eco-efficient mines will contribute to improved access to domestic mineral resources, secure the sustainable supply of mineral raw materials for Europe and reduce the import dependency. IntelliMine will contribute to realise these concepts of invisible, zero-impact and safe mines. The mine of tomorrow will run an integrated concept in order to guarantee the desired level of sustainability. All operations necessary for the eco-efficient provision of the minerals including waste management will be carried out underground. This will drastically reduce the volumes being transported, minimising above ground installations and thus the environmental impact. IntelliMine will develop necessary innovative methods, technologies, machines and equipment for the safe, eco-innovative, intelligent and economic exploitation of mineral raw materials in the EU, especially at greater depths."

Jan 1, 2011

By M. A. Boucher

The purpose of my presentation is threefold: a) to make you aware of what is available in Canada in terms of refractory minerals. b) indicate the mineral deposits that have potential for development. c) show the advantages of Canada as a supplier of electrical energy necessary for the production of electrofused minerals. Canada is a producer of natural refractory minerals, electrofused minerals, and synthetic refractory minerals. Several deposits also have good potential for development. The natural refractory minerals produced in Canada are shown in Table 1. The major minerals by decreasing order of importance in terms of tonnage and values are: dolomite, graphite and magnesite.

Jan 1, 1992

By Tim O’Neil

Many mining companies try to fight their way up from small operator and exploration company to major producer. Not many companies make it. Cambior Inc., formed in 1986, is one company well on its way to making it as a major operating company. In 1993, Cambior surpassed 15.5 t (500,000 oz) of gold production and began operations at its world class Omai gold mine in Guyana. At the same time, the company has embarked on a program of geographic and minerals diversification. Cambior, a Canadian company, now has interests in eight mines, three development projects and more than 100 exploration properties in North and South America. The company’s goal is to derive 70% of its income from gold and 30% from base metals and other minerals. Cambior’s moderate diversification into base metals gives protection against negative gold price fluctuations. It also balances the typically short term gold mines and the longer term base metal mines.

Jan 1, 1994

By R. Hogg

Sedimentation in highly flocculated suspensions of fine particles such as clays occurs through individual settling units (flocs) which have very open structures and correspondingly low density -typically less than 5% solids by volume. It follows that such settling processes rapidly lead to the build-up of a bed of flocs which are essentially close-packed, with inter-floc porosity of perhaps 50%, but with an overall solids content of no more than about 2-3 percent by volume. An important consequence is that the thickening process is dominated by the consolidation of this bed rather than by simple settling of the individual flocs. Experimental measurements of sediment consolidation in flocculated clay suspensions indicate that for a given system, consolidation rates are essentially determined by solids concentration and can be evaluated using the classical Kynch treatment. However, these rates are strongly dependent on the physical as well as chemical conditions of the flocculation process. Furthermore the extent to which gravity consolidation proceeds depends on the total weight of sediment (i.e. on both height and solids concentration). The implications with respect to thickener operation and the requirements for laboratory testing for thickener design are discussed.

Jan 1, 1992

By M. Rieber

In July 1985, as the U.S. copper industry contracted and the Mexican industry expanded, a trans border pollution agreement was signed which included smelter air pollution control in the "Gray Triangle": Cananea, Nacozari and Douglas. Since then the Douglas smelter has been closed, a year earlier than initially required; though its new smelter is operating, S02 collection and acid disposal at Nacozari is yet to come; and the Cananea smelter has been un-touched. Nacozari and Cananea copper mining have expanded while a reduced U.S. copper industry has rationalized to a point of fragile profitability. As a paradigm of U.S. copper competitiveness, this paper attempts to explain the differential fortunes of copper in the two countries, to project the future of the smelter agreement as a function of acid disposal, and to consider the consequences of the politicized application of smelter pollution control in Arizona.

Jan 1, 1988

By Gennaro Gerald Marino

Vast improvement in methods of design and analysis of the long- term stability of overburden above room and pillar mines is needed. Improved methods are vital for planning and land development and for prediction above existing, presently stable, room and pillar mines. As shown on the flow chart in [Figure 1], the assessment of the long-term stability is an integral part of the site investigation process regarding mitigation of surface damage effects. In Illinois, flat farmlands with subjacent coal reserves cover vast areas. In some of these areas high extraction of the underlying coal layer(s) may not be possible since the resulting surf ace subsidence combined with a pre-existing shallow water table would make the land too wet. Thus recovery of this coal might only be accomplished by room and pillar mining where the ground surface does not subside and the hydraulics of the overburden are not significantly affected.

Jan 1, 1986

By E. J. Freech

In this part of the two-part paper we discuss briefly the adaptation of the comminution model to describe the observed behavior of an industrial grinding circuit. Although reported verification of comminution models for continuous systems is limited, some interesting work has been reported 1,2 recently. The data acquisition and modeling efforts are described first, followed by discussion of some of the simulation results. Observations pertinent to steady-state operation are presented followed by a description of the application of a dynamic model of the grinding circuit for synthesis and evaluation of grinding-circuit control. The pilot-scale work indicated the comminution model should be capable of describing an industrial size-reduction process. Recognizing the broad utility of a process model based on first- principles, the Industrial Nucleonics Corporation of Columbus, Ohio, embarked on a joint program with the Duval Corporation of Tucson, Arizona, to evaluate the industrial applicability of the models described in Part I. This program was conducted in a grinding circuit, which included a rod mill 12.5 feet in diameter and 16 feet long and a ball mill 12.5 feet in diameter and 14 feet long, at Duval Corporation's Esperanza property3. The rod mill was operated in open circuit and the ball mill in closed circuit with cyclone classifiers.

Jan 1, 1970

By Verya Nasri, Heather M. Ivory, Kevin Clarke, Eric Cole

Development of the New York City Water Supply System The New York City water supply system serves a population of almost nine million, including residents in neighboring counties. Peak day demands on the system are currently running at about 70 m3/sec (about 1,600 mgd), which is significantly lower than in the 1990s. This trend of reducing demands over the past 25 years, which has been experienced in other major urban centers in the US, is mainly the result of conservation measures and increased cost consciousness on the part of water users. In the long term, demands are expected to once again follow an increasing trend with population growth, so that by the end of the planning horizon of these studies, the year2045, the peak day demand is expected to increase to about 85 m3/sec (2,000 mgd).The system is served largely by surface water sources, regulated by a system of 19reservoirs and three controlled lakes, which are connected to the City by a series of aqueducts, the longest of which is about 87 km (54 miles). The total storage in the sys-tem amounts to about 560 billion gallons, providing a system firm yield of about1300 mgd. The Delaware system provides about 50% of the City’s water, the Catskill about 40%, with the remaining 10% provided by the Croton. The system as a whole, which is shown on Figure 1, has been built up over the past 150 years, and is truly a marvel of engineering. The Catskill and Delaware aqueducts both discharge into Kensico Reservoir, which is a daily balancing reservoir located in Westchester County about 24 km(15 miles) north of the New York City line. The two aqueducts extend south for a further 14 miles to combine again at Hillview Reservoir in the Bronx, which provides hourly balancing storage for New York City system. The Croton aqueduct runs nearby as shown on Figure 2, but does not connect into the two reservoirs. From Hillview Reservoir the water is supplied to the city via three main distribution tunnels, known as City Tunnels 1, 2, and 3. City Tunnel No.1 was developed in the 1920s as part of the Catskill system. City Tunnel No. 2 followed in the 1960s as part of the Delaware system. City Tunnel No. 3 (CT3) is partly under construction and partly in operation, and is being implemented to permit the other distribution tunnels to be taken out of operation for the first time for inspection and maintenance. Presently CT3 is supplied with water from Hillview Reservoir via a large underground valve chamber, the Van

Jan 1, 2007

By Vladimir Nikolić, Alex Doll

The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work index methodology for designing and measuring the efficiency of mineral grinding circuits. In spite of being called “Bond’s Law,” the work index equations are not a law of nature; but rather an empirically measured regression of a large data set collected by the Allis- Chalmers corporation in the period between 1930 and 1952. As a regression, it is valid within a specific “calibration space,” and great care is required when deviating the test procedures or observing results that are outside of that calibration space. This paper is a collected summary of other works by the Authors that describe feed sizes, product sizes, quality control checks, and other information about interpreting the test and using its results. Examples of adjustments that are sometimes required when using the test are: changing the test product (P80), and coping with a feed that is too fine to apply the “proper” feed preparation steps (such as is sometimes observed from HPGR or SAGDesign product testing). Related metrics, like the Morrell Mib value and Levin B value will be discussed, along with recommendations for their use on design projects. The intended audience is any user of laboratory work index test data.

Feb 1, 2024

By W. L. Staker

The Bureau of Mines investigated selective extraction of Au and Ag from a low-grade Au ore containing Hg. Gold and silver were extracted from the ore in cyanide slurries, and Hg extraction was suppressed with sodium or calcium sulfide. Maximum Au extraction and minimum Hg extraction were obtained using solutions containing 0.34 lb NaCN/ton of solution. Increasing the cyanide concentration increased Hg extraction without increasing Au extraction. Mercury extraction from the ore was suppressed with 0-5 to 2.9 Pb CaS/lb Kg in the ore. Gold-to-mercury ratios of 100:1 to 400:1 were obtained in the leach solution, and on the activated carbon in a CIP circuit.

Jan 1, 1983

By T. I. Martinovic

A major investigative' program was conducted on the development of an acceptable substitute organic binder for bentonite for the pelletizing of the Iron Ore Company of Canada's Carol concentrate. The first phase of the program covered an evaluation of several organic binders in laboratory tire balling in order to identify the most promising potential organic binders. Based on the green ball quality obtained, Peridur C-10, Alchem 8C26 and peat moss were selected for full scale pot-grate testwork. The selected binders were tested with various pelletizing mixes (acid, dolomite, limestone and fully fluxed). The pot-grate test results showed that an acceptable pellet quality can be produced with the use of Peridur C-10.

Jan 1, 1989

By Yasushi Arai

"Among Tokyo Metro’s approximately 200km of subway lines, the Tozai Line that connects Chiba Prefecture and mid-Tokyo experiences congestion of up to 199% at worst and relief of this has become urgent. Therefore, as it is imperative to increase the number of trains operating in the exceptionally congested area from mid-Tokyo going east, a large-scale renovation work is planned between Iidabashi Station and Kudanshita Station that will facilitate turn-back via 3 tracks. While ensuring the safe and stable operation responsible for about 1.35 million passengers daily, this highly difficult work of inner wall demolition and reinforcement of the side walls and floor slabs will only be implemented for 3 hours during late night. This paper discusses large-scale plans to improve turn-back facilities, and the methods of construction therein as an example of operational improvement of a subway network. 1) INTRODUCTION The Tokyo Metro Tozai Line (“Tozai Line”) opened over the entire 30.8 km distance from Nakano to Nishi-funabashi on March 29, 1969. It has the longest operating length of the nine Tokyo Metro lines, and was the first subway line to extend past the borders of the Tokyo Metropolis. Through train services with two other railway companies are available from the Tozai Line. Tozai Line trains join the Sobu Line of the East Japan Railway Company (“JR East”) and the Toyo Rapid Railway Line of Toyo Rapid Railway (“TR”) from Nishi-funabashi Station, and the JR Chuo Line from Nakano Station. The line is structurally distinctive in that 51% of it was built using the open-cut method, 43% of it is elevated and the remaining 6% was built when we used the shield method for the first time 1)2)3)."

Jan 1, 2016

By R. M. Enick

A novel liquid-liquid separation for the recovery of free or liberated gold from mixtures of fine particles was evaluated. The separation, conducted at ambient temperature and a pressure of about 1000 psi a, was based on the difference in wettability of precious metals and minerals. Contact angle results indicated that in the presence of water and liquid CO2, gold, platinum and silver had intermediate wettability. Minerals such as quartz and magnetite, however, were hydrophilic. Therefore fine gold particles. -325 mesh, that were mixed with water and liquid CO2 dispersed in the CO2 or agglomerated at the H2O-CO2 interface while the minerals tended to remain in the aqueous phase. Best results were obtained when these fine gold particles were liberated, were not agglomerated in slimes, were not adhering to minerals, and were not coated with minerals.

Jan 1, 1998

By Tom Gonzales

At San Manuel, AZ, Magma Metals Co. operates an Outokumpu flash furnace, four Peirce-Smith converters and two anode casting wheels that are supported by six anode vessels. Process gasses from the flash furnace and converters are treated in a two-train/ double-contact sulfuric acid plant. The plant captures 98% of the sulfur. A new flash furnace was commissioned in July 1988. It has since processed more than 2.7 Mt (3 million st) of sulfide concentrate without a major rebuild. The company has gained unique experience in the operation of the flash furnace at high oxygen enrichments with low off-gas dust loadings. New procedures have been developed to maintain secondary material generation at equilibrium and for maintaining metallurgical control of operating parameters. Process flow description At Magma's San Manuel plant, concentrates and other copper-bearing material are blended and conveyed from two separate areas of the plant to three 420 t (465 st) capacity wet charge bins located above the rotary dryer. Flash furnace silica flux is conveyed to a 227-t (250-st) capacity fine flux bin located adjacent to the wet charge bins. The concentrate and flux are blended in controlled amounts and fed into a 168-t/ h (185-stph) gas-fired rotary dryer. The wet charge enters the dryer at 8% moisture and is dried to 0.2% moisture. The dried charge is pneumatically conveyed to a 580-t/h (640-stph) dry charge bin located above the flash furnace. Flash furnace charge is drawn from the bin by two drag conveyors at a concentrate feed rate of 145 t/h (160 stph). The charge is mixed with enriched combustion air and injected into the furnace reaction shaft. In the reaction shaft, the charge is oxidized to form matte, slag and a rich SO, off-gas.

Jan 1, 1992

By William H. Wiese

Anecdotal reports of high rates of congenital malformations and spontaneous abortions at the Shiprock Indian Health Service Hospital in San Juan County, New Mexico prompted an interview survey, obtaining data from families of 26 former uranium miners and 30 controls. Results supported the possibility of increased fetal wastage and congenital malformations. However, definitive conclusions were obviated by methodologic limitations in terms of selection of cases and controls and interviewing technique, as well as very low numbers and lack of statistical significance. The Council of Environmental Quality (1980) published a report which singled out San Juan County, nationally, as having an extra-ordinary high rate of congenital anomalies reported from birth certificates in the years 1973-75. San Juan County is in the northwest corner of New Mexico and includes the northeastern edge of the Navajo Indian Reservation. It has been the site of uranium mining and milling and also of coal mining (Clement Associates, 1980). While much attention has been focused on lung cancer and chronic lung disease as health hazards to uranium miners, virtually no attention has been focused upon possible reproductive effects that may result from exposure to radiation. Could these reports indicate such an additional arena of health effect either on miners or on others living in the vicinity of the mines and mills? The biologic and epidemiologic literature does not lend much support for adverse genetic outcome. The UNSCEAR report (UNSCEAR, 1977) summarizes much of the existing data. For example, on the basis of many animal studies and what has been observed in atom bomb survivers in Japan, it has been estimated that mutation rates resulting from low LET radiation to paternal germ cells would be 60 X 10-6 recessive and 20 X 10-6 dominant mutations per gamete per rad. There would be a five-fold increase in the number of recognizable abortions. The doubling dose for genetic disorders in mice is estimated at 100 rads. The assumption has been that low levels of exposure, such as might be received occupationally from uranium mines and mills or environmentally will produce reproductive effects that would defy distinction from background rates. However, the possibility can not be dismissed. In man, spermatogonia are thought to be three-fold more sensitive than in the mouse. Also, the high LET radiation from alpha particles is as much as 20-fold more effective in inducing changes in meiotic and post meiotic stages of cells, compared with low LET radiation. There is some degree of localization of alpha emitters in testicular tissue after inhalation of radon and radon daughters (Blanchard, R.L. and Moore, J.B., 1971; Pohl, E., 1964). The slopes of doseeffect curves are affected by type radiation and rate of administration. Data on such curves are poorly defined and debated as to whether there may be increased or decreased effect per unit dose at low levels of high LET radiation. Increased rates of aberrations of chromosomes in peripheral lymphocytes cultured from uranium miners have been reported (Brandom, W.F., et al., 1978). At cumulative exposures of 100 working level months (WLM) or less, a range of exposure lower than the limit of current occupational standards, the aberrations were increased more than two-fold. Our interest has led us to pursue the question of reproductive effects along three separate paths of inquiry: studies of the secondary sex ratio, cytogenetic study of human sperm, and studies of rates of congenital anomalies. I will present the thrust of our findings, most of which remain preliminary, comment on their interpretation and limitations, and indicate directions needed for future research. The secondary sex ratio is the ratio of males to females at birth. In the U.S., the ratio averages around 1.05. Ratios in blacks are somewhat lower (1.025) than in whites (1.053). For American Indians, the data are less definite. Values from Oklahoma and California are similar to whites (1.05). Southwestern tribes have, as we shall see, varying levels. The theoretical effects on sex ratio resulting from irradiation of the zygote are based on the principles of sex-linked genetics, including differential effects of lethal dominant and recessive mutations on the sex chromosomes, complicated by possible non-disjunctional events. Observations have done little to clarify, confirm or refute the theories. The sex ratio of progeny of survivers of the atomic bomb showed little change (Schull, W.J., Otake, M., and Neel, J.V., 1981). Observations in children of uranium miners having been inconsistent. Most frequently cited is a study of miners in Czechoslovakia (Müller, C., Razicka, L., and Bakstein, J., 1967). Compared with children born to miners prior to the start of mining, the sex ratios of children born after the start of mining were decreased -statistically significant after correcting for birth order. The ratios in first-born children were, before the start of mining, 1.118, and, after the start of mining, .713. In the interview survey at Shiprock, the sex ratio in families of non-miners was 1.03, and in families of miners it was 0.73 (p < .05). Dr. Alan Goodman at the University of New Mexico has studied trends in the sex ratio in the general population in New Mexico and Arizona with particular reference to counties in the Four Corners area and the Navajo Indian Reservation, areas where uranium mining has been active_ His findings (unpublished) are as follows: (1) Beginning in the early 1950&apos;s, there has been a modest, but persistant and statistically significant decline in the secondary sex ratio for the state of New Mexico compared with the U.S., a decline that roughly parallels the emergence of uranium mining in the Grants mineral belt in northwestern New Mexico. (2) Data available for the 11 years since 1969 show that among the five counties with ratios significantly lower than the state

Jan 1, 1981

By Roshan B. Bhappu

Although the economic importance of recovering copper by leaching of mine work dumps from open-pit operations has been realized for some time, serious attempts to understand and to improve such operations through scientific research has been made only in recent years. This progress report covers the results of chemical, physical, and biological studies pertaining to the dump leaching process and discusses salient features and parameters that may be helpful in improving such operations.

Jan 1, 1968

By Mustafa Kumral, Yu Cheng Yang, Zhixuan Shao, Young Bin Moon

Since the discoveries of favorable deposits are becoming increasingly difficult, mining operations shift to lower grade and deeper deposits. The viability of these operations is sensitive to many factors, such as commodity prices and operating costs. Given that a mining corporation has no power to set prices, the focus is directed on minimizing the operating costs. Underground mining operations require a network infrastructure, including shaft, ramps, declines, levels, cross-cuts, raises, winzes, and adit. The design of this network is a costly process. As such, it has a significant potential to reduce development and haulage costs. Furthermore, network design is a continuous process along with development, production, and maintenance throughout mine life. Under the constraints of the turning radius, the gradient, and the obstacle avoidance for haulage network of underground mines, this paper first demonstrates network design and optimization approaches using Dubins path combined with the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm. A threshold-based model is developed, providing viable solutions to the network design when the number of declines is high. Furthermore, a three-dimensional Rapid-exploring Random Tree (RRT) algorithm combined with Dubins path is employed as a heuristic solver for obstacle avoidance purposes in the network. Various case studies are conducted to show the applicability of the proposed methods.

May 24, 2023

By K. C. Shaver

The Sloan Ranch kimberlite complex is located approximately 130 km north-northwest of Denver in the Precambrian core of the northern Colorado Front Range (Figure 1). A Devonian age for the complex is suggested by the fossil assemblages in limestone xenoliths (Chronic and others, 1969), and by paleomagnetism of the kimberlite (E. E. Larson, personal communication, 1986). The presence of diamond was first reported in rocks from the Sloan diatreme by McCallum and Mabarak (1976). Prior to this time, the distinctive- appearing host rock of the Sloan diamonds had been quarried for use as terrazzo stone; examples may be seen in the floors of the airports in Cheyenne and Laramie, Wyoming. The Minerals Division of The Superior Oil Company obtained a lease on the Sloan property in 1980. During the next four years Superior built and fine-tuned a highly efficient diamond recovery facility, explored and tested the Sloan deposit, and used Sloan as a site for testing numerous exploration techniques for future use in a continuing exploration program in the Colorado-Wyoming kimberlite province. The Sloan property was ultimately determined to be sub- economic, but the lessons learned there have been very helpful in subsequent exploration efforts.

Jan 1, 1987

By J. Kang

To obtain microbial cultures with the ability to efficiently leach copper ion from chalcopyrite, microbial samples from acid mine drainage sites were mixed and then subjected to mutation using sodium nitrite (NaNO2), diethyl sulfate (DES), ultraviolet light (UV) and their combinations. Mixed cultures with a much stronger ability to leach copper ion (identified as mixed cultures A, B, C, D and E) were obtained by screening on leaching media. Leaching tests showed that mixed culture E had the best leaching performance and increased the Cu2+ content by 120.5% in 20 days, compared to a control without mutation treatment. Mixed culture E grows well on Leathen leaching medium supplemented with Cu2+ (at a final concentration of 32 g/L), reaching 3.2 × 107 cells/L after 15 days, while the unmutated control culture cannot survive beyond 15 days, indicating that mixed culture E is more tolerant of high concentrations of Cu2+. In addition, continuous leaching by mixed culture E is very effective at a pulp density of 1%. These results suggest that it has the potential for industrial applications.

Jan 1, 2008

By Wayne C. Smith

Both water pollution and proposed solid waste disposal regulations have a definite effect on the copper leaching industry and some of the major factors affecting the industry are discussed in this paper. New developments of the NDPS are discussed with emphasis on the "toxic" or priority pollutants and EPA&apos;s philosophy on the control of these pollutants, The protection of groundwater is the prime aim of RCRA through solid/hazardous waste management. Some of the major elements of the RCA regulations that will affect the copper leaching industry are discussed.

Jan 1, 1980