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By L. Xiao, P. Somasundaran

Using potassium oleate as a collector and alizarin red S as a modifying agent, selective depression of dolomite from francolite was achieved in an alkaline medium (pH > 9.0). Adsorption of alizarin reds alone on dolomite was found to be higher than that on francolite. Complimentary adsorption experiments of alizarin red S and oleate showed that oleate adsorprion was increased in the presence of alizaring red S. The results are explained in terms of comparative adsorption for the active sites on francolite and dolomite by oleate and alizarin red S and their interactions with dissolved mineral species in solution.

Jan 1, 1990

By J. D. Miller

Certain bituminous coals of recent geological age are known to contain a significant quantity of natural (fossil or subfossil) resin. Such resinous coals are found in the western U.S., particularly the Wasatch Plateau coal field in Utah. Some of the seams in this field contain approximately 5% resin which has been recovered by gravity and/or flotation processes since 1929. Resin concentrates thus produced are of low quality and are usually refined by solvent extraction and precipitation. The purified resins are of commercial importance, being used in the adhesive, varnish, enamel and ink industries, etc: Recently, an improved flotation technique has been developed which involves ozone conditioning to selectively float resin from such coals. In this flotation process, a concentrate product which contains 95% resin at a recovery of 80% can be obtained in a single stage from coal containing approximately 10% resin, whereas conventional flotation at a similar level of recovery produces a concentrate having a resin content of 30-40%. Economic analysis shows that the ozone flotation process has good potential for use by industry.

Jan 1, 1988

By Michael E. Allen

The building of sanitary and storm drainage sewers in urban or environmentally sensitive areas often requires the use of tunnel construction procedures. While hydraulic considerations may require only small diameters, traditional tunneling techniques make small sizes the least economical. Current state-of-the-art techniques using highly mechanized systems of pipe jacking can provide cost effective solutions to the problems of construction of small size tunnels. The characteristics of mechanized pipe jacking allow rapid advances under difficult ground conditions. The basic pipe jacking cycle is used with a variety of excavation systems to permit the contractor to satisfy engineering as well as economic parameters. These characteristics and several of the systems available are outlined.

Jan 1, 1981

By Alva L. Kuestemeyer, Randall J. Scott

INTRODUCTION Pincock, Allen & Bolt, Inc. (PAH) has developed a series of cost models for Western U.S. Gold Mines. The models indicate the economic potential of developing gold properties at various production rates and ore grades. Various combinations of mining and processing methods are also analyzed. The conclusions shown in this paper are taken from PAH's 600 page study titled, "Capital and Operating Cost Models for Western U.S. Gold Mines." PAH decided to develop the cost manual as a result of our perception of the industry's need for such a document. It was our impression that exploration development decisions were being made on the basis of limited economic information. PAH has compiled a substantial database on unit cost information. That database and the engineering capabilities of the firm allowed us to develop a reasonably detailed analysis of capital and operating costs and overall development economics. The study has developed a series of algorithms for underground and open pit mining, processing, G&A, and infrastructure costs. The capital and operating cost data served as a basis for performing after tax discounted cash flow analysis for the various development alternatives. For the base case scenarios, a 15% DCFROR was assumed and the required ore grade was back calculated using the computer. The ore grade versus production rate graphs summarize the economics of developing gold projects in the Western U.S.

Jan 1, 1987

By E. M. Frizzell

This paper addresses the use of the microcomputer programs BACKONE and BACKWEDG for an estimation of rock mass strength characteristics by back analysis of plane and wedge failures. The artificial support requirements are also determined by the programs PLANE2, BOLTPAT, and BOLTWEDG in terms of rock anchor installation angles, tensions, and installation patterns. These programs have been combined into a package called BACKPACK, which can be applied in open pit mines where some failures have already occurred.

Jan 1, 1988

By S. K. Mukherjee, M. M. Singh, N. I. Jayaramn

In underground mining operations, ventilation and water sprays are the common methods of controlling dust. In recent years, there has been a proliferation of technical literature dealing with water sprays for dust control. However, guidelines for the design of an effective water spray system have not been presented to the mining industry. This paper recommends guidelines for water spray systems to control dust in underground mining operations. These guidelines suggest type, number, location, and orientation of nozzles; desirable operating water pressure; and associated filtration system.

Jan 1, 1987

By Annan Cook

J.R. Atkinson, office engineer to Kennecott Copper Corp., summarized data on the Mineral Park area [Wallapai (Chloride) Mining District, Mohave County, Arizona, Fig. 1] and submitted it to the New York office in 1950. He recommended an examination. Weston Bourret, a Kennecott geologist, accompanied by B.S. Butler, the well known former US Geological Survey geologist, examined the larger of two hydrothermally altered areas in Mineral Park that same year. Bourret recommended that the property be optioned and mapped. Georges Ordonez, Kennecott's chief geologist, after a field examination, agreed with Bourret's conclusions At the end of the summer of 1951, Annan Cook (another Kennecott geologist) accompanied Ordonez to the property prior to starting a mapping program. At Ithaca Peak, the structure, alteration, and reddish-brown coloring in leached cavities-hematite, jarosite, and goethite with minor copper staining - made an interesting target. The Peak, which has since been mined, was a Laramide quartz monzonite porphyry grading into quartz porphyry, penetrating Precambrian rocks. Turquoise had been mined from several workings on the Peak. Surrounding the central area of alteration, but mainly to the northwest, there were many long-abandoned underground workings mined for zinc, lead, gold, silver, and copper. To the west of Ithaca Peak within the main area of alteration, surface evidence of a chum drill hole suggested interest in the disseminated mineralization probably prior to World War II. A topographic and geologic survey of the altered Ithaca Peak area was initiated by Cook in September 1951. He was assisted by Richard Vosburgh, field engineer, and by four geologists: Charles Goddard, III, Donlon LoBionda, Keith Martin, and A.T. Stone. When Cook returned to New York, Vosburgh was left in charge. Mapping continued and diamond drilling took place during the winter of 1951-1952. Drill sites were selected entirely on the basis of surface geology. Five drill holes, including a flat hole, located around the flanks of Ithaca Peak, averaged about 183 m (600 ft) in length. A sixth hole caved at less than 60 m (200 ft). The best values obtained were in the first hole (-45°): 90 m (300 ft) averaged 0.62% copper and 103 m (337 ft) averaged 0.041% molybdenum. In another hole, 43 m (142 ft) averaged 1.09% copper and 0:023% molybdenum. The values of copper and molybdenum in these two holes were generally higher than in the remaining holes, although molybdenum values were always around 0.024% or better. The New York office decided, however, to abandon the project even though the remaining field crew of three had recommended more drilling.

Jan 1, 1991

By J. D. Scott

This paper consists of a review of the development and application of spherical charge blasting at Inco Metals Company. Topics will include the Livingston Strain Equation, the field data required for its use in full scale operation, the type of ground in which mining has been carried out, explosives in use and their characteristics and finally, an overview of actual production applications. These applications include Primary Stope Mining, Secondary Mining Against Fill, Mining a Faulted Ore Zone and Drop Raise Blasting. INTRODUCTION Crater blasting in itself has been in use for over twenty years, but only recently has the technique been combined with a spherical size charge to form the Vertical Retreat Mining Method. This article endeavours to put the Livingston Strain Equation in a practical light, to describe several actual hard rock applications, and the results achieved in each case. THE LIVINGSTON STRAIN ENERGY EQUATION C.W. Livingston put forward the following equation as a standard means of determining the optimum burden required for full crater production blasting. The constant "E" is included in an attempt to recognize secondary breakage caused by strain waves.

Jan 1, 1981

By J. A. Herbst, Y. C. Lo

An attempt has been made to parameterize the population balance model for a ball mill based on measurements of the elementary breakage process obtained using an ultrafast load cell device. Detailed insight obtained concerning the fragmentation of particle assemblies with the ultrafast load cell leads to a better understanding of ball mill grinding. The ball mill breakage function and specific selection function are derived from an average single event representing the multiple breakage events which occur in ball mill grinding. Since both the breakage function and the specific selection function depend on the loading mode in the mill, predictions of breakage mechanisms in ball mills are possible by using data obtained in various elementary loading modes. The application of this model to the description of batch ball milling behavior has resulted in reasonably accurate predictions of product size distributions for various energy inputs.

Jan 1, 1992

By James Y. Oldshue, Paul M. Kubera

Ore processing requirements in the gold industry are similar to those in other sectors of the minerals industry. In all cases, the processes revolve around the handling of large volumes of ore slurry, incorporating either physical processing or chemical processing steps which are related to distinct mixing application classes as defined in Table 1. From this standpoint, the complexity of the applications range from the simple (blending, solid suspension, etc.) to the complex (e.g., multi-phase reactor systems). The large volume of material to be processed dictates the large equipment size which is characteristic of this industry, and the often remote locations place a premium on both mechanical and process reliability.

Jan 1, 1992

By G. W. Luxbacher

Acid rain legislation included in the Clean Air Act Amendments of 1990 caused a great deal of uncertainty regarding the price, source and production quantities of coal supplied to the eastern coal market. Powder River Basin and other western coals continue a rapidly accelerating migration eastward. South American coals move into the northern markets. States are proposing legislation to assist utilities in complying with the new regulations in hopes of maintaining their own coal industries. Some utilities question the long-term availability of eastern compliance coal. Major coal producers must make decisions now to assure their continuing presence in the market place. Several companies have adopted a strategy to acquire eastern compliance reserves, while others have invested in technology to compete as a low-cost producer. Legislation "Acid rain." This is a topic that was debated within the scientific, environmental and industrial communities for years. Those discussions resulted in a large outlay for the federal National Acid Precipitation Assessment Project (NAPAP), which was then ignored. Acid rain then became the subject of a "60 Minutes" broadcast that debunked the acid rain theory, supporting the NAPAP study conclusions. In the final outcome, however, acid rain was the driver for the Clean Air Act Amendments of 1990.

Jan 1, 1992

By Michel Grenier, David A. Young, Brent Rubeli, Mahe Gangal

This work forms part of a study being conducted into the feasibility of constructing a prototype Load Haul Dump (LHD) vehicle for operation in underground Canadian mines. A series of in-laboratory assessments were performed to determine the relative contributions of a Deutz F4L912W (54 HP- conventional vehicle engine) and a Deutz F2L 2011 (31 HP hybrid vehicle engine) to diesel emissions concentration during mine transient duty cycles and steady-state operating modes respectively. Results indicate significant reductions in the quantity of gaseous and particulate emissions with the application of the hybrid system and a high-efficiency ceramic element filter. This paper describes the engine test protocols and the results of this laboratory study.

Jan 1, 2006

By A. C. Beaulieu

CITY OF EDMONTON Rate of Growth The City of Edmonton has been classed by some economists as being the most progressive City in Canada since the early 50's. The high rise buildings that are changing Edmonton's skyline, the rapidly expanding sewer and water network, and the proposed rapid transit system all indicate the requirements of an ever expanding City. Edmonton, the core of Canada's Energy Empire is the country's seventh largest metropolitan area. Bisected by the 22 mile long park of its magnificent river valley, it sits in the midst of the 50,000 sq miles of riches that have created it. Underneath the City, however, extending down for thousands of feet and encircling it for a radius of scores of miles, lies a fabulous store of petroleum wealth. By the early 1940's, based upon the needs of the farming areas, accompanied by some small exploitation of coal and timber, Edmonton grew to 100,000 people. Then in a short space of 20 years Edmonton shot up to be a city of 450,000. Figure 1 (Slide No. 1) indicates the population growth in the City of Edmonton and the Census Metropolitan Area from 1906 to 1971.

Jan 1, 1997

By R. D. Miller, L. Schulte, J. Davenport, D. W. Steeples

Shallow seismic reflection methods were successfully used to delineate the subsurface extent of roof failure associated with the dissolution mining of a 120-m (400 ft) deep and 60-m (200ft) thick salt bed in central Kansas. Surface subsidence at North American Salt's Hutchinson, KS, salt-dissolution well field represents a potential risk to surface structures and transportation facilities. Three intersecting common depth point (CDP) seismic reflection profiles, targeting the subsurface around an actively subsiding sinkhole, possess sufficient resolution to delineate the horizontal and vertical extent of subsurface rock failure associated with the subsidence. The three seismic profiles showed a disturbed subsurface area 90 to 105 m-diam (300 to 350 ft-diam) at a depth of between 60 to 75 m (200 ft and 250 ft). Confirmation drilling verified the interpretation of the seismic data. The seismic reflection method has the potential to resolve disturbed subsurface areas greater than 23 m-diam (75 ft-diam) at this site.

Jan 1, 1994

By Mary Ann Harrington Baker, John Trudnowski, Marietta Canty, Marek Zaluski

Three Sulfate-Reducing Bacteria (SRB) passive field-bioreactors were constructed at an abandoned mine site near Butte, Montana, to mitigate AMD emanating from a waste rock pile. Each SRB field-bioreactor contains chambers of an organic source, limestone, and cobbles. The field-bioreactors are configured differently to test the effect of different environmental conditions on the SRB. Preliminary observations indicate that, during start up and the first eight months of operation, the quantity of organic carbon supply significantly impacts the SRB activity. To date, the dissolved metals have been reduced significantly and the pH has increased.

Jan 1, 2000

By H. Sis, S. Chander

The beneficial effect of a series nonylphenol polyethylene glycol ether surfactants were tested in the flotation of phosphate ores in which the mixture of sodium oleate and dodecane was used as collector. The performance of nonionic surfactants was first tested in the microflotation of pure apatite mineral. Microflotation experiments showed that the recovery of apatite depends on the number of ethoxylation of the nonylphenol surfactants and decreased with higher ethoxylation. The nonionic surfactant with the smallest ethoxylation group used in this research (NP-4) was then tested in batch flotation of phosphate ores. The flotation of three different size phosphate ores was carried out in the absence and presence of NP-4 surfactant. The beneficial effect of nonionic surfactant was obtained for fine size (-35+150 mesh) and very fine size (-150+400 mesh) phosphate ores at different collector dosages studied. But, in the flotation of coarse size (-16+ 35 mesh) phosphate ore the beneficial effect of nonionic surfactant was obtained only at high collector dosages.

Jan 1, 2002

By G. Belardi, G. Marruzzo, P. Plescia

This paper presents the results of grinding tests performed on magnetite from Kiruna (Sweden) and on chromite from Skoumtza (Macedonia. Greece). Stresses were measured by XRD, which determined the variations in the characteristic structural spacings of the minerals both before and after, grinding in a HSM/250 Herzog laboratory ring mill. Anal Isis of the magnetite and c hromite crystallinstallin was performed hi measuring the broadening of the strongest diffraction peak (311). .Also, structural analysis on chromite was carried out using the Mikheev model. Ultrafine-grinding tests on the magnetite and chomite demonstrated that this type of treatment can induce profound variations m the surface-stress state. These included plastic variations of the cell followed by "chemical" stress with oxidation front the stricture to form hydroxide or carbonate, films. This can have a great influence on the mineral reactivity to flotation reagents

Jan 1, 1996

By W. V. Harper

The travel path of a freed radioactive particle in an aquifer must be estimated from a limited number of available samples. This paper discusses geostatistical methods that minimize the 'uncertainty' associated with the predicted hydrologic surfaces and the predicted travel path. However, any estimation method will produce a single smooth predicted path. This 'sensitivity' will he evaluated using a geostatistical simulation method. The techniques will be illustrated using published data from the Wolfcamp and Pennsylvanian aquifers in the northern Texas Panhandle.

Jan 1, 1990

By Y. Nakahiro, T. Wakamatsu, M. S. Elsalmawy

The flotation of quartz, feldspar and alumina was studied as a function of pH when using N-alkyldiamines as collectors. The lengths of alkyl chains of diamines were 8, 9, 10, and 12 carbon atoms. It was found that shorter hydrocarbon chain length of alkyldiamines has stronger tendency to float quartz while the feldspar responded poorly to flotation with these collectors at high pH values. The effect of addition of nonionic surfactant of Brij type, when using dodecadiamine as collector, was investigated. Flotation studies in the absence and in the presence of sodium dodecylsulfonate were carried out. These studies have indicated that sodium dodecylsulfonate, in the concentration studied, functions as strong depressant for feldspar.

Jan 1, 1995

By I. de Jong, G. Van Weert

Silver cyanide adsorbs extremely well on activated carbons. This suggests that the addition of soluble silver salts to trace cyanide containing waste streams should allow efficient cyanide removal with active carbon. Silver losses, however, would make this method expensive and also objectionable, since silver has biocidal effects. When silver impregnated carbon is used, these problems are overcome. Test work has shown that such silver remains on or in the active carbon, that cyanide concentrations can be reduced to the level of detection (< 5 ppb) and that the silver impregnated carbon can be reactivated with equipment similar to that now in use at gold milling operations. Initial results on the type of carbon, the impregnation procedure and the level of silver, and the effect of repeated regeneration are discussed.

Jan 1, 1992