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By F. F. Aplan

Prologue Antoine Marc Gaudin (Fig. 1) was truly a giant in the field of mineral processing, and his shadow is still cast long on our profession. "Tony," as his students affectionately called him (but never to his face), came to the United States in 1917 and enrolled at Columbia University where he studied under Professor Arthur F. Taggart. Later, as a lecturer, he wrote his classic comminution paper (Gaudin, 1926). This important work led to his appointment as an associate professor at The University of Utah, where he conducted highly original work on flotation fundamentals that is still widely quoted today (Gaudin et al., 1928-30). In 1929, he was appointed Research Professor of Ore Dressing at the Montana School of Mines in Butte. Shortly thereafter, he published his first book, Flotation (Gaudin, 1932). Because Gaudin could so quickly cut through the fog to get to the essence of a problem, this is still a valuable reference book. It is a valued part of my personal library, and I consult it frequently. Over the next decade, he conducted an outstanding graduate research program at Butte, but, more importantly, he honed his undergraduate lectures and produced the century's outstanding text in the field, Elements of Mineral Dressing (Gaudin, 1939). More than 50 years later, this terse book is still found to contain most of the elements of the discipline. Its sections on the

Jan 1, 1994

By K. N. Han, H. C. Cho, R. Kim

"As an extension of the work on the effect of OH- on various cations in hydrometallurgical systems, the effect of Cl-, Br-, I- and CN- on cations such as Ag+, Cd2+, Hg2+, Cu+, Cu2+, Co2+, Zn2+, Pb2+ and Sn2+ has been examined in detail. The Newton-Raphson technique has been used to determine the amounts of various metal species as a function of the concentration of anions. Some practical implications of various metal complexes in metal separation and removal from solutions have been examined and discussed.IntroductionUnderstanding the role of anions in hydrometallurgical processes often determines the success of an operation. The successful choice of concentration and type of anions not only leads to an effective extraction and removal of metals (Esmaeili et al., 2005; Brbooti et al., 2011; Wei et al., 2005; Jeppesen et al., 2009; Al-Tarazi et al., 2004), but also to assisting effective separation of various metals, whether it is a solvent extraction, ion exchange operation or even a simple precipitation (Farha et al., 2011; Sevenich and Fritz, 1983; Rashid, 1974).This paper continues the discussion of the role of anions in hydrometallurgical systems beyond the role of OH-, which was the topic of a previous paper (Kim et al., 2014). Table 1 lists various anions that are frequently used in conjunction with metal ions to be selectively separated or precipitated. As seen in the table, many anions are used frequently in hydrometallurgical practices. Some of the more frequently used anions include OH-, SO4 2- and CO3 2-. The halogen elements, Cl-, Br- and I- , as well as CN-, are also used in hydrometallurgical applications, especially in relation to noble metal recoveries (Meng and Han, 1994; Zhang et al., 1996; Sun et al., 1996; Starovoytov et al., 2007)."

Jan 1, 2015

By W. N. Brown

One of the seemingly eternal problems with which we are frequently faced is that of providing adequate and economical warehousing facilities to store large quantities of bulk product. Seasonal consumption, transportation, marketing, and other factors very often dictate extensive product warehousing requirements for an operation geared for steady, year-around production of a material requiring weather protection during storage. Fertilizers such as potash and urea are examples of such products; the consumption of these materials is extremely heavy in the early spring at which time the materials must be placed in the soil, whereas, for obvious operating efficiencies, production is more or less constant for a given operation throughout the year.

Jan 1, 1961

By Sam H. Patterson

The advances in knowledge of world bauxite resources in the last few decades include contributions to the geology of deposits, discovery of large resources, shifts in availability, and changes in. the industry in response to political and economic pressure. Improvements in the understanding of geology have resulted from the larger numbers of geologists working on bauxite and better exchanges of information. The large deposits discovered are mainly the laterite type in tropical regions. These discoveries have led to major increases in bauxite resource estimates as well as to shifts in bauxite availability and in the ranking of producing nations. Changes resulting from political, environmental, and economic pressures have resulted in increased costs of bauxite and in renewed interest in potential nonbauxite sources of aluminum. Aluminum is produced from nonbauxite raw materials only in the U.S.S.R.; however, research on extraction processes or investigations of nonbauxite alumina resources has taken place in several countries.

Jan 1, 1984

By Marion A. Goudie

The Devonian salt basin, which contains the Saskatchewan Potash deposits, extends from just east of the foothills in Alberta, north as far as the Peace River area, across Saskatchewan and into Manitoba as far east as Range 10 west of the First Meridian and south into Montana and North Dakota. The basin is closed everywhere except to the northwest. The known potash deposits are confined almost entirely to the Province of Saskatchewan, with the exception of a small area in western Manitoba bordering the Saskatchewan boundary. The following discussion will concern only the Saskatchewan part of the basin. The evaporite series in the basin is defined as the Prairie Evaporite Formation of the Elk Point Group, of Middle Devonian age. Recent work done by potassium-argon dating methods has indicated an Upper Middle Devonian (Givetian) age of from 265 to 347 million years for the potash. The Elk Point Group consists in ascending order of the Ashern, Winnipegosis and Prairie Evaporite Formations. The Ashern formation, sometimes called the Third Red Bed, consists of dolomitic shales or shaly dolomites. The Winnipegosis is a reef type dolomite, usually with good porosity, and in many cases oil-staining, although to date no production has been obtained. The Prairie Evaporite formation consists of anhydrite overlain by halite and finally, in Saskatchewan, by the potash beds. In almost all wells which have been cored for potash the lowest potash bed is underlain by one or two bands of anhydrtte, which are used as marker horizons. Cores from a few wells which cored to the bottom of the salt series have shown flecks of potash throughout the halite.

Jan 1, 1959

By M. G. Schulz

Mining of molybdenum at Questa, New Mexico has been accomplished by block cave methods since August, 1983. As caving progresses, a periodic geologic evaluation is made of the rock-types present in finger raises on the Grizzly Level of the mine. The production maturity of the cave can be monitored by relating this data to geologic cross-sections through the ore body. The draw point mapping program is a simple and effective tool that is used in making draw control decisions at Questa.

Jan 1, 1985

By M. J. Virnig, Marc Le Vier, Rong Yu Wan, Jan D. Miller

Although most gold production from primary resources is achieved by cyanidation, many research activities have focused on alternative processes using noncyanide lixiviants. Such research has been prompted by environmental concerns and problems associated with the processing of refractory gold ores. Numerous research projects have been conducted to search for a noncyanide hydrometallurgical process for gold extraction. In this paper, a technical review of gold recovery from noncyanide solutions is presented, and new results are reported. Gold recovery techniques that are considered include activated carbon adsorption, cementation, solvent extraction, ion exchange, and reduction-precipitation.

Jan 1, 1993

By Cynthia M. Walck, S. K. Grant, R. D. Hagni

The Post Gold deposit is located in the northern part of the Carlin trend. The mineralization at Post occurs in proximity to a Jurassic-Cretaceous composite stock. Most of the gold at Post is hosted by non-metamorphosed calcareous siltstone and highly altered diorite, adjacent to the low grade skarn. Endoskarn, exoskarn, hornfels and marble are developed outward from the intrusive. The skarn is composed dominantly of diopside, tightly intergrown with gannet, k -feldspar, and sphene. The highest grade gold values are adjacent to the skarn, which acted as a permeability barrier to fluid migration. Post is the first Carlin-type deposit at which a skarn has been recognized to play a significant role in the localization of gold.

Jan 1, 1990

By Jon “Ike” Isaacson, Frank Perrone, Eric Prantil

"Tunneling through an urban environment carries many inherent risks to the immediate local infrastructure and subsequently to the project stakeholders. On the CQ031 Contract of the East Side Access Project in Queens, New York, twin 22.5’ diameter Herrenknecht Slurry TBMs were mined within close proximity to many infrastructure assets, with cover of less than half a shield diameter at times. Multiple public bridges and critical railroad infrastructure including catenary poles and signal towers supporting the busiest rail interlocking in the United States required underpinning systems. The support program for these structures was refined over the course of the four tunnel drives. It is the intent of this paper to show how the interaction between the temporary structures, instrumentation monitoring plan, and risk assessment program melded to provide a system which the owner, contractor, and designer relied on as a tool to ensure the project success without impacting the public surroundings. PROJECT BACKGROUND The East Side Access (ESA) megaproject located in New York City, N.Y is a multi billion dollar program for the Metropolitan Transit Authority Capital Construction (MTACC) with the main goal of bringing the Long Island Railroad (LIRR) commuter rail to Grand Central Station located in the heart of Midtown Manhattan. When completed, the project will significantly reduce congestion both into and out of Penn Station, the current terminus of the LIRR. In order to accomplish this, multiple contracts of varying scope are required to operate simultaneously in both Queens, N.Y and Manhattan. In 2009, the CQ031 Queens Bored Tunnels Contract was awarded to the joint venture of Granite Construction Northeast, Traylor Bros. Inc., and Frontier Kemper (G.T.F). The main scope of this contract was to excavate four segmentally lined soft ground tunnels underneath the Sunnyside Rail Yard in Queens, New York. Additional scope of work included the construction of a tunnel approach structure, electrical substation, and multipurpose ventilation and egress facility."

Jan 1, 2016

By Phil Allen

A synthetic fiber manufactured by one chemical company has been treated by another chemical company to produce a cloth fabric capable of performing ion-exchange functions. Only a few delimiting parameters have been established. This paper will discuss briefly the highlights of a functioning ion-exchange cloth. Throughout the paper this fabric will be referred to as "Fabric Z".

Jan 1, 1970

By H. J. H. Pieterse

This paper highlights the mineralogy of the Barrick Goldstrike Mines Inc. area. The mine is located at the north end of the Tuscarora Spur and is part of the Bluestar/Goldstrike subdistrict of the Carlin Trend. The Betze, Post, and Meikle Mine are major deposits located in the area. The deportment of gold, its leachability, and various process options are also evaluated. Particular emphasis is given to the practical and economic considerations of ore control, and routing of ore to a process option.

Jan 1, 1993

In spite of our deep conviction that it would be wrong for the United States to enter World War II, when, after Pearl Harbor, we were actually in it, I felt that I must do all I could to help. The country had been so good to me that I could not decently stay on the sidelines. My first thought was that I might help with supply and administration in the Air Force, as in World War I. So on the evening of Pearl Harbor I wired the chief of our Air Force in Washington saying that I had been on Gen. William Mitchell's staff in World War I and was offering my services again. I received a noncommital answer, but after a couple of weeks was told to take my physical examination. I passed it, but nothing further happened. After helping to make plans for the wartime operations of Summit King and Desert Silver, Dorothy and I went to New York to spend Christmas with Molly and Peter, both of whom were in college in the East. I had to complete a report on the Argonaut mine in California first, though the war made my recommendations of dubious validity. Before Christmas I received wires from Temple Bridgeman, Phil Wilson, and other friends who had taken positions with government agencies responsible for securing mineral products needed for war use. They urged me to join them. It was evidently a case of not whether but how I could be most useful. After six uncertain days with the family in New York I took the night train to Washington on the 28th of December. I had a hectic day there. First I saw Arthur Bunker and Phil Wilson at what became the Aluminum and Magnesium Division of the War Production Board. Their office was in an old converted barracks. They asked me to examine magnesium deposits in Nevada at once, and then to look at other magnesium and aluminum properties. After leaving

Jan 1, 1976

By J. H. Rowland

Four different types of fire suppression systems were evaluated in large-scale fire experiments to study the effect of air velocity on the effectiveness to extinguish conveyor belt fires. The four different types of suppression systems were water sprinkler, deluge type water spray, and two different dry chemical fire suppression systems. The large-scale fire tests were conducted with 72-in-wide fire resistant rubber belt that met the Mine Safety and Health Administration flame resistant requirement specified in Title 30, Code of Federal Regulations, Part 18, section 18.65 (also known as the 2G Flame Test). Each fire suppression system was tested at air velocities of 500-550 feet per minute (fpm) and 1350-1500 fpm. Two tests were conducted at both air velocities for each fire suppression system. Both of the water-based fire suppression systems were able to suppress the fire to the point that a miner could extinguish it with a fire extinguisher. However, the amount of water needed to suppress the fire to the point where a miner could walk up to extinguish any smoldering belting was greater than the current MSHA regulations require. MSHA regulations only require 10 minutes of water supply to the suppression system. In the test set up neither of these systems would have suppressed the fire had the water been turned off to the system after 10 minutes. The dry chemical suppression systems produced mixed results. Dry chemical suppression system A did not suppress the conveyor belt fire at either air velocity. Dry chemical system B suppressed the fire at 500 fpm air velocity, but produced mixed results at the higher air velocity. Details are presented on the large-scale fire test set-up, arrangement of the fire suppression systems, and conclusions regarding the effect of air velocity on fire suppression system design and performance. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of NIOSH.

Jan 1, 2009

By D. F. Cater

The Macassa Mine is a mature mine with a 61 year history of continuous production. The majority of past production has been derived from a zone called the '04 Break (Main Break). Recent underground mine exploration has been successful in locating several neighbouring ninera1ized zones. This paper will characterize the spatial location, geometry and mineralogical properties of these secondary zones. Future plans for underground mine exploration to follow-up on these target zones will be outlined.

Jan 1, 1995

By Ken Pill, Jennifer Nyman, Liz Moran, Keaton Belli, Chelsea Bokman

The Moab Uranium Mill Tailings Remedial Action (UMTRA) Project Site (Site) is a former uranium-ore processing facility near Moab, Utah, where production ended in 1984. The United States Department of Energy Office of Environmental Management (DOE-EM) is responsible for remediating the site to meet 40 Code of Federal Regulations (CFR) 192 standards promulgated by the United States Environmental Protection Agency under the authority of the Nuclear Regulatory Commission (NRC). Tailings from the former mill were stored in an unlined impoundment (tailings pile), totaling 16 million tons of waste material. Surface cleanup has been ongoing since 2009 and consists of removal and transport of tailings via rail to an off-site disposal facility in Crescent Junction, Utah, with an estimated completion date around 2029. Gravity-driven migration of tailings fluids and recharge through the tailings pile and former on-site ore storage areas in the northeastern part of the site led to contamination of site soil and groundwater. The primary contaminant of concern is ammonia, which was present in fluids used in the milling process (DOE 2003). Uranium is a contaminant of potential concern. An interim groundwater remedy is currently in place that utilizes a system of extraction and injection wells to limit discharge of contaminated groundwater into the nearby Colorado River. Exceedance of surface water standards for ammonia are a principal concern due to potential endangered species fish habitat areas along the Colorado River adjacent to the Site. When necessary, surface water diversion is used to lower surface water ammonia concentrations when suitable habitats develop for endangered young-of-year fish. Once surface cleanup concludes and the tailings pile is removed, a formal groundwater remedy must be selected and documented in a Groundwater Compliance Action Plan (GCAP). Under Title 1 of the Uranium Mill Tailings Radiation Control Act, natural flushing (i.e., monitored natural attenuation), may be selected as the groundwater remedy if it can be demonstrated that the remedy will achieve groundwater standards within 100 years. The 40 CFR 192 groundwater standard for uranium is 44 micrograms per liter (μg/L), and the target groundwater concentration of ammonia based on adverse effects on local fish species is 3 milligrams per liter (mg/L). A collaboration with Geosyntec Consultants, Inc. (Geosyntec), the Moab UMTRA Project team, the DOE Office of Legacy Management, the DOE-EM, and the Network of National Laboratories for Environmental Management and Stewardship was held in 2022 with the goal to generate actionable recommendations to develop a GCAP for the Site. The primary recommendation was development of a groundwater fate and transport model to predict the remedial timeframe under various groundwater remedies. This paper presents the results of soil and groundwater sampling, geochemical modelling, and laboratory column and batch reactor testing that will be used to parameterize a numerical model for estimating the remedial timeframe under various scenarios, including natural flushing.

Feb 1, 2025

By Saman Khaleghparast, Naj Aziz, Jan Nemcik, Guanyu Yang

"More than 25 years of uninterrupted research on ground support technology for underground mines has been undertaken at the University of Wollongong. This research has resulted in significant findings on tendon characteristics and strength properties. The paper focuses on the development of the fourth generation of cylindrically shaped shear test apparatus for assessing tendon performance in shear. This shear apparatus is known as the MK-IV Double Shear Box or Naj Aziz Double Shear Box (NADSB), and is based on the experience gained from the development of previous versions of rectangular double shear boxes. The new NADSB is circular in shape and is fitted with a truss system, which permits friction free shear testing of tendons across joint planes. A series of double shear tests were carried out on a number of cable bolts commonly used in Australian mines, both plain and indented wires, under varied pretension loads. The results were compared with similar test results using rectangular shaped double shear apparatus, with and without friction across joint faces. The significance of wire surface roughness and increased initial pretension loads are discussed and conclusions made, suggesting that indented wires are inferior in shear compared with plain cable bolts. The general test procedure of the NADSB is described and different concrete reinforcement techniques are reported. The influence of external and internal confinement of the concrete medium blocks in a circular double shear box contributed to consistent test results with a minimum of lateral and axial cracks occurring in the host medium.INTRODUCTIONThe use of long tendon ground support elements (cable bolts) is now a common practice in modern underground coal mines, hard rock mines, tunnels and other underground structures. Due to their material properties cable bolts contribute significantly to the overall ground reinforcement provided by a support system. Cable properties in tension and shear are in many cases vital to maintaining a safe and productive underground environment. Accordingly, tension and shear properties must be assessed accurately using both valid and reliable methods.Load transfer property testing of tendons has been studied over several decades with much of the early research focused on the pull and shear testing of solid rock bolts and hollow bolts (like Swellex and split set tube bolts), as these elements were used extensively at this time. It was not until the 1970’s that the use of cables for ground reinforcement developed, and as such highlighted the need to extend load transfer property testing to include shear strength of cable bolts. Initially, the discarded hoisting ropes were used for ground support in metal mines, particularly in stopping wall support and then late in 1980’s cable tendons began to use in coal mines."

Jan 1, 2019

By L. H. E. Weyher

The Bethlehem Mines Corp. is a captive mining subsidiary of Bethlehem Steel Corp. Its coal production is tied to the demands for and production of steel, a situation that has to balance between the following two extreme strategies: (1) either the mines are designed and operated for some optimum production level and the demand fluctuations within the steel corporation are met by supplementary corporate coal sales and purchases, or (2) the mines absorb all the demand fluctuations, regardless of the effects on mine costs. A rational definition of the best strategy between these extremes is, of course, needed but is very difficult to formulate in view of the complexity of the many factors that would have to be included in the analysis. Consequently, rather than setting profit targets for each given mining division and/or individual mine, the practice evolved to set production targets for producing specified tonnages of coking coal for shipments to the ovens located at the corporation's iron and steelmaking plants. This in turn leaves the mines with the dilemma of having to explain demand-related cost-per-ton fluctuations while essentially depriving them of the ability to control profit through tonnage optimization. In the early 1970's, the coal prices rose significantly, while other factors led to sagging productivity in underground coal mining. Thus, the role of Bethlehem's coal operations in the corporate profit picture gained in relative importance. This, in turn, sparked a closer attention to the coal mining cost structure and factors controlling productivity. At the same time, the drastic increase in the capital needed to open a new mine also increased the amount of planning required to minimize risks. All of this called for more well-defined, quantitative operating data. Bethlehem therefore launched, in the early 1970's, a number of innovative steps that, as the future may show, represented pioneering contributions to the growing sophistication of North American underground coal mine planning and management control practices. This case study describes the changes that led to the current implementation of a novel production reporting system at Bethlehem's coal mines. These changes took place in two distinctly different phases. The current system that resulted from the Phase II developments utilizes, of course, experience gained earlier and is expected to be amplified to incorporate more advanced concepts and technology as future experience dictates.

Jan 1, 1979

By Jack Barrett

The oxidants which participate in the bacterially catalyzed oxidation of minerals are dissolved oxygen and some aqueous iron(III) complexes. Speciation studies indicate that these complexes consist of iron (III) -sulfate and iron (III) -arsenate ions. The complexes have different oxidizing powers as indicated by their calculated standard reduction potentials. The thermodynamics of the oxidations of pyrite and arsenopyrite are related to the mechanisms of the reactions. The mechanisms are discussed in terms of primary processes occurring on the mineral surfaces and the secondary reactions of the primary products. The importance of the conclusions to plant operation is discussed.

Jan 1, 1993

By V. Ramirez, M. Mankosa, G. Luttrell, E. Wasmund

"The performance of column flotation is strongly influenced by the effectiveness of the gas sparging system. Unfortunately, field studies suggest that gas injector systems used for column sparging are not always optimized. This unfavorable condition can create a number of issues within the concentrator including lower recoveries, poorer metallurgical upgrading, decreased capacities, increased circulating loads, higher reagent consumption and inefficient energy usage. To help overcome these problems, techniques have been developed that can be adopted by plant operators to improve sparger performance. These techniques include (i) design modifications to sparger components such as nozzles, distributors and internal parts and (ii) operational improvements such as proper balancing of gas/water flows, elimination of unnecessary pressure drops, and staged injection of frothing agents. This article reviews the important criteria that govern sparger operation and provides data showing how simple low-cost improvements can positively impact column performance. INTRODUCTION Column flotation cells have become the most popular machine design for industrial applications that require high purity concentrates. The superior metallurgical performance of column cells can be largely attributed to their unique geometry, which readily accommodates the use of froth washing systems. The wash water minimizes the nonselective entrainment of ultrafine gangue minerals that would otherwise be hydraulically carried in the water reporting to the froth concentrate. The larger height-to-diameter ratio of columns allows a deep froth to be maintained, which is essential to achieve even water distribution. Due to these unique features, column cells can provide impressive levels of metallurgical performance closely approaching the ultimate separation curve predicted using the flotation release analysis method (Kohmuench et al., 2007). Another very important feature of column cells is the design of the gas sparging system. One popular choice in the minerals processing industry is the Eriez SlamJet® sparger. As shown in Figure 1, this type of sparger operates by passing compressed gas through a small discharge nozzle. Fluid turbulence created by the exiting gas disperses and distributes small bubbles into the flotation pulp. The sparger is equipped with an internal moveable rod that is attached to a pressure diaphragm in the back housing of the sparger. The internal rod automatically moves back/forward and opens/closes the nozzle outlet when the compressed gas is switched on/off. This patented design effectively eliminates the accidental backflow of flotation pulp into the injection tube during shutdowns. The sparger can be operated as a gas-only injector or with the introduction of a small amount of high-pressure sparger water (Kohmuench et al., 2010)."

Jan 1, 2016

By David J. Kruse

Accurate field measurements are essential when validating a conveyor design. They are fundamental in determining a conveyor's behavior, its long-term maintenance requirements, and the life expectancy/ condition of the installed equipment. Field measurements are also invaluable in forensic engineering, particularly when vital equipment has failed This paper will discuss a wide variety of data acquisition equipment, field measurement techniques and accuracies achieved State-of-the-art, custom designed monitoring equipment, as well as, ''08-the-shely instruments and sensors, will be discussed.

Jan 1, 2004