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By Don L. Deardorff

The Deserado Mine and transportation system is the fuel supply portion of the Bonanza Power Plant project. Deserado Mine con¬sists of an underground mine with a capacity of 1,224,700 tonnes (1,350,000 tons) of clean coal per year, a 649 tonne (715 tons) per hour closed water circuit jig type preparation plant, a 5.6-kilometer (3 ½ -mile) overland conveyor with covered slot storage, a unit train rail load-out and 59.5 kilometers (37 miles) of totally independ¬ent, captive electrified railroad. Planning and exploration started in March of 1978. Construction of all facilities was completed in April of 1984, approximately six years after initial planning was commenced. This paper will discuss exploration, environmental permitting, mine planning, engineering and construction of the Deserado Mine project.

Jan 1, 1984

By Juan L. Sepulveda

An MPSI KW-20 Tower mill has been tested at the Butte Molybdenum plant of Anaconda Minerals Company, as a substitute for the conventional 1.5x3.0 m (5x10 ft) tumbling ball mill currently used for regrind purposes. The Tower mill was operated in both open and closed continuous circuits. These results were complemented with a series of batch grinding tests to determine some of the operational features of this mill. The relative grinding efficiency of the Tower mill with respect to the tumbling ball mill was determined and the applicability of this new mill to a plant/heavy duty environment was assessed. Experimental results obtained on the regrind of moly concentrates indicate that approximately 40% energy savings can be realized by using the Tower mill instead of the ball mill.

Jan 1, 1984

By P. A. Mingione

AEROPHINE® 3418A is a unique sulfide mineral promoter produced by Cyanamid, based on phosphine (PH3) chemistry. It has proven effective as a collector for the sulfide minerals of copper and particularly lead (galena), as well as for secondary gold and silver values. AEROPHINE 3418A has widest application as a Cu and/or Pb collector for complex ores of Cu-Zn and Pb-Zn, which frequently have significant quantities of associated precious metal values. Advantages shown in the use of AEROPHINE 3418A are improved selectivities against Zn-and Fe-sulfides, increased precious metals recoveries, reduced total collector consumptions for Cu and/or Pb flotation, and increased flotation kinetics leading to higher recoveries of these values. Operating plant, pilot plant and laboratory test data from treat-ing different ores are presented, demonstrating the advantages in use and preferred application of AEROPHINE 3418A.

Jan 1, 1991

By K. J. Stanaway

Concentrations of minerals between 3.5 and 5 specific gravity such as ilmenite, rutile and zircon in large accumulations of sand constitute "heavy mineral" placers. Two fundamentally different modes of formation characterize "trap" and "bed" placer variants. Smaller and generally higher grade trap placers form during sediment erosion or reworking. Because of their smaller size, they rarely yield economic heavy mineral deposits. They become economic, either if they contain more valuable "heavies" such as gold, or, if they occur within or near much larger but lower grade bed placers. Bed placers form during sediment accumulation episodes in any environment and lithofacies where mineral supply and fluid dynamics are favorable. Three heavy mineral deposits are discussed to illustrate bed placer geology and how trap placers occur with and relate to them.

Jan 1, 1991

By J. E. Murphy, Y. Topkaya, R. E. Johnson, B. R. Palmer, D. K. Dysinger, R. B. Bhappu, A. E. Clark

The U.S. Bureau of Mines utilized a central composite experimental design to investigate leaching kinetics of pure chalcopyrite in the sulfuric acid-oxygen system. The six factors studied were oxygen pressures of 150, 300 and 450 PSI, leach temperatures of 35O, 65O, and 95O C, oxygen-to-chalcopyrite mass ratios of 0.5, 1.0 and 1.5, leach times of 8, 16 and 24 hours, initial acid strengths of 0.6, 1.2 and 1.8 g H,SO,/g chalcopyrite and pyrite to chalcopyrite mass ratios of 0, 1, and 2. Chemical analysis and oxygen consumption measurements indicatedthat leaching occurs through three consecutive reactions. Temperature was the primary determinant of leach rate and solution acidity was the primary determinant of oxygen consumption, sulfur oxidation, and activation energy.

Jan 1, 1993

By Russell. A. Smith

This paper describes some recent work on the identification and development of new chemical reagents aimed at improving the industrial processing of phosphate ores by froth flotation. In particular, three chemical product families which will be discussed appear to offer enhanced flexibility by: 1) utilizing a small amount of a silica control reagent which can significantly reduce the amount of anionic (carboxylic) collector required for a given P2O5 recovery level; 2) utilizing a new anionic collector family which offers high P2O5 recovery and selectivity versus standard carboxylic collectors; and 3) utilizing another new anionic collector family which has, in some tests, allowed for selective removal of dolomite from apatite. Examples and use characteristics of each of these new chemical ideas will be presented.

Jan 1, 1993

By John G. Reid

Geologists, employed by the Australian Company, Metals Exploration Limited, discovered nickel laterite enrichment at Greenvale in 1967. A joint venture was arranged with the Freeport Minerals Company who had gained early experience with nickel laterite ores when building and operating the Nicaro and Moa Bay Treatment Plants in Cuba. A 5 tonne/day Pilot Plant at the Freeport research facilities at Belle Chasse, Louisiana, verified the amenability of the ore to treatment by the reduction and ammonia-ammonium carbonate leaching process used at Nicaro. A 5 800 tonne/day Treatment Plant was constructed on the coast at Yabulu, North Queensland. This paper describes the ore body, the mining operation and the stages of treatment required to produce nickel oxide products and a mixed nickel/cobalt sulphide product at Yabulu.

Jan 1, 1979

By K. H. Bettles

The Goldstrike Mine is in Eureka County, Nevada, approximately 23 miles northwest of the town of Carlin. The mine is at the north end of the Tuscarora Spur of the Tuscarora mountains at elevations of 5,300 feet to 5,950 feet. It is part of the Bluestar/Goldstrike subdistrict of the Carlin Trend of sediment hosted, disseminated gold deposits. The Carlin trend comprises over 15 major gold deposits with production, reserves and geological resources of approximately 50 million ounces of gold (Fig. 1). In the Bluestar/Goldstrike subdistrict, there are four major deposits; Post, Betze, Bluestar, and Genesis, plus numerous smaller deposits (Fig. 2). Betze is located on property controlled by Barrick Goldstrike Mines; Bluestar and Genesis on Newmont Gold property; and Post on both Barrick and Newmont property.

Jan 1, 1989

By C. Copeland, S. Kawatra

Airborne particulates can be generated by combustion processes, comminution, or materials handling, and regulation of these particulates by EPA are becoming progressively more stringent. Regulations will soon include “nanoparticulates,” particles finer than 100 nanometers, which are believed to have significant health effects due to their high surface area and reactivity. Although it was argued that nanoparticulate concerns were only important for combustion, studies here have shown that material handling and comminution release significant quantities of nanoparticles into the air. Laboratory studies have shown that sodium metasilicate reduced airborne particles finer than 10 micrometers (PM10) by 86% and particles finer than 2.5 micrometers (PM2.5) by 80% for iron ore. Additional studies were conducted which revealed that nanoparticulate emissions were present in the types of operations conducted at pyrometallurgical facilities.

Jan 1, 2007

By John L. Watson, Suren Mishra

Many of the wastes produced by modern steel plants are pulps or sludges containing significant concentrations of iron and displaying some ferromagnetic characteristics. These waste materials are often suited to treatment by magnetic cycloning to produce a high solids content underflow and a clean water overflow. Alternatively in the classification mode, the magnetic cyclone can produce a high iron underflow product for recycling by discarding fine non-magnetic material to the overflow. Results for the treatment of a variety of steel plant wastes in 5.0cm, 2.5cm and 1.25cm diameter cyclones, operating with and without an applied magnetic field, are presented. It is demonstrated that the magnetic cyclone increases solids recovery to the underflow product, especially at finer particle sizes and for higher solids content feed pulps.

Jan 1, 1992

By Shelley M. Burg, Dennis K. Poulton, Robert B. Gordon

This project includes the excavation and concrete lining of approximately 18 900 m (62 000 ft) of 5.5 m (18 ft) finished diameter subway tunnel for the Los Angeles MTA. The project required that four soft ground headings be excavated from a single shaft located near the mid point of the tunnels. The tunnels were classified "gassy" during the excavation phase. Because of the contract schedule requirements and the limited urban work site available, many logistical problems had to be overcome during the project while excavation was accomplished at a record setting pace. Some unique project features include the muck handling system and an access shaft using a high strength tieback support system. In order to accomplish the work, an extensive effort to plan and construct the main work site was required.

Jan 1, 1995

By Ph. Vandebrouck

SUMMARY In August 1986, TRANSMANCHE LINK, a joint venture comprising the 10 companies who initially promoted the project, signed a contract with EUROTUNNEL for the design, construction and commissioning of the TRANSMANCHE fixed link for an amount of 4,5 billion dollars. On the French side, the work consists of digging three, 19km. long tunnels, of which almost 16 kms. are under the sea, up to the meeting point with the Tunnel works carried out by the British.. The tunnels are bored through chalk by 5 tunnelling machines, starting from one intermediate point at Sangatte near the coast: - Landward, they are drilled trough permeable strata of white and grey chalk. - Seaward, mainly through relatively impermeable chalk marl, but with the presence of water in faulted zones, or in grey chalk.

Jan 1, 1989

By W. M. Shaver, R. Letourneau, W. R. Dengler

Dynatec Mining Limited contracted to sink a 1500 metre (4960 ft.) concrete lined shaft for Falconbridge Nickel Mines in Sudbury, Ontario, Canada. The shaft is 6.3 metres (20.5 ft) in diameter inside the concrete lining and is equipped with steel furnishings. Dynatec used the owner supplied 4.6 metre (15 ft.) diameter double-drum hoist to sink the shaft with 12.5 tonne buckets for muck removal and 4 cubic metre concrete buckets for concrete placement. One of the unique features of the shaft sinking operation is the use of a four-boom electric hydraulic drill jumbo permanently mounted in the shaft sinking stage. This paper will describe the performance obtained with the electric hydraulic drilling equipment and the high capacity muck removal and concreting equipment.

Jan 1, 1991

By D. R. Nagaraj

Secondary Ion Mass Spectroscopy (SIMS) was used to study adsorption of sulfide collectors such as modified thionocarbamates and thioureas, xanthate, dithiophosphate, and dithiophosphinate, on galena, chalcocite, chalcopyrite, and quartz under flotation related conditions. In the case of the adsorption of modified thiourea on chalcopyrite, chalcocite and Cu-activated quartz, and of dithiophosphinate on galena, SIMS measurements have provided direct evidence for the presence of metal-collector (1:1) complexes on surfaces. In the other systems, only the collector molecular ion and its fragments were detected. The distribution of adsorbed species on the surfaces was obtained by using SIMS in the imaging mode. On chalcopyrite, only the copper-collector complex was found; there was no evidence for iron-collector complex. In the case of quartz, adsorption of selective collectors was observed only after activation by copper ions.

Jan 1, 1996

By D. Hodouin

The paper reviews approaches to estimate in a real time fashion consistent mass flowrates and assays, using data from the on-stream analyzers and flowmeters of a flotation circuit. Results obtained with one algorithm operating on-line with an industrial flotation circuit are presented.

Jan 1, 1996

By Walter E. Heinrichs

To many, petroleum exploration and successful geophysics , are partly synonomous, This is not because natural petroleum is usually concentrated as a liquid, nor certainly not because oil can be detected directly. The reason is Chat geophysics helps to at least better understand and sometimes, to even explain the essential geology involved. That groundwater is similarly a liquid with all but a few of its basic geologic relationships practically identical to petroleum, seems to have escaped many of those most interested and responsible for complete geo-hydrologic knowledge. The paramount need to use every means at our disposal for maintaining and expanding our crustal resources reserves are generally obvious, However, in view of the rapidly mounting requirements, continual re-emphasis is worthwhile.

Jan 1, 1963

By James R. Dunn

The mineral industry" has made and will continue to make important contributions to the growth of our economy. However, the industry is presently under continuous and increasingly severe attacks by organizations and individuals interested in the preservation of our environment. Yet neither the public interest value of preservation nor the public interest value of our mineral industry is known. In the absence of such values, judgments about best land use where minerals are involved are nearly always made on emotional grounds. An example of the sort of problem that has been created is in the New York Metropolitan Area. Because of institutionally-created shortages stemming largely from zoning decisions and building over deposits, the effective cost of fine aggregate delivered at dockside at Manhattan rose from $2. 65/cubic yard in July, 1969, to $4.10/cubic yard in May, 1970, this in spite of approximately ;l0,000 years of reserves on Long Island. The cost of fine aggregate for New York City alone has "Increased over $S million annually within one year, with the cost increase for the Tri-State Metropolitan Area (coastal Connecticut, New Jersey, and New York)" exceeding $10 million annually. The ab0ve situation has created a cost increase which is clearly the result of non-conservation of a mineral resource. That is, in readily measurable values, it Is costing the public about $10 million per year because good conservation practices were ignored-a public-interest loss. Admittedly, this is not the whole story because the public is simultaneously obtaining other values from the land surface that would otherwise have had to be dedicated, temporarily to be sure, to mineral recovery-a public-interest gain. However, the point is that we do not know where the balance lies-the net public interest value; it may lie one way for deposits zoned out of existence by a growing suburb, another for areas designed as permanent greenbelts, and still another for areas under new highways

Jan 1, 1971

By Nikhil Dhawan, Shrey Agrawal, SHAILA MIR

The current study investigates the effect of microwave processing on low-grade banded iron ore using charcoal, coking coal, and non-coking coal. Charcoal showed better microwave heating response at low temperatures, and the coals exhibit better heating response at higher temperatures. Low carbon dosage ~ 12% is sufficient to generate concentrate with 61.8% iron grade and ~6% for 94.8% iron recovery comprising of magnetite phase suitable for iron-making applications. The process separation efficiency of ~ 95% is achieved at 6% carbon dosage and decreases with an increase in carbon due to formation of the fayalite phase. The metallization degree showed a strong dependency on reductant dosage and achieved amaximumvalue of 22.7%at 18%charcoal. The comparison of ore with pure iron oxide and the synthetic mixture of iron oxide indicated that the underlying bonding due to banded structure enhances the Joule heating during microwave irradiation and thereby aids in attaining higher temperature and better separation.

Sep 21, 2020

By Nicholas Chlumecky

A practical method is described for determining or checking whether underground supports such as props, posts and mechanized longwall supports have bearing areas of proper size in relation to the type of ground or floor strata on which they are standing, It is felt that this information provides an approach to eliminate, as much as possible, a potential grave source of error during the selection of roof supports. This would also affect the choice of costly mechanized longwall equipment where it is possible that the size of the bearing area is not as carefully determined as, for instance, the design strength of structural components.

Jan 1, 1967

By R. W. M. Lai

The study of flotation kinetics was first reported by Garcia-Zuniga1 in 1935. Since then, literature on the subject has grown with the time. 2-19 Although there is an abundance of flotation kinet¬ics models available in the literature to describe flo¬tation systems, they are mostly of academic interest and are seldom applicable for use in the industrial environment. Several reasons contribute to the wide gap in the industrial -application of the academic models. These include: 1) the lack of generality in the model, e.g., the model is limited to certain size ranges; 14 2) the academic models involve complicated mathematics; 5,6,10,11 3) confusion about the order of the flo¬tation rate, e.g., several authors proposed a first order rate model, 1,15,16 whereas the others propagated a second order rate model: 2,17,18,194) the use of an unrealistic rigid value, such as the use of a maximum recovery of 100%, 5,8,19 which is unrealistic in industrial operations; and 5) the use of graphs that confuse the reader rather than interpret information. 2,3,10 This paper intends to introduce a simple and easy to understand empirical flotation kinetics model along with a way of presenting the model in an informative graphical form, which should stimulate the interest of other practical engineers to become concerned with practical application within the mineral industry.

Jan 1, 1982