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By M. Deniz Turan, HASAN NIZAMOGLU, Z. ABIDIN SARI, Tolga Depci

Chalcopyrite extraction in an aqueous acid medium occurs through solid transformations into distinct intermediaries. As intermediates, mineral phases CuS, Cu2 S and Cu5 FeS4 may generate in the leaching solution before CuFeS2 completely decomposes to Cu2+, Fe2+ and S0. Oxalic acid is a common organic acid, and it dissolves easily in warm water. Due to the chelating feature of oxalic acid, it hinders iron precipitation by composing soluble complex anions in a wide range of pH. In this study, recovery of copper from solid material (obtained by leaching of chalcopyrite with oxalic acid in the presence of hydrogen peroxide) with a copper oxalate structure was carried out selectively using hydrochloric acid (HCl). Selective recovery of copper by degrading the copper oxalate structure with a low-solubility product (Ksp= 4.43 × 10 −10) was performed by conventional leaching in the presence of HCl.

By T. V. Subrahmanyam

Unlike coarse particles (40-50 µm), the fines (<10 µm) have low collision efficiencies with gas bubbles in flotation process. Among the alternative methods for recovering the fines are their aggregation with coarse particles (carrier flotation) and flocculation of the fines alone (shear-flocculation), prior to flotation. In any case, hydrophobic aggregation is the mechanism involved though the technique is known by different names in literature. This paper deals with theory and state-of-the-art of particle aggregation. To illustrate the dependence of aggregation on particle hydrophobicity, charge and, in turn, the sheer force, the results of quartz-DDACI and galena-xanthate systems are considered. In the flotation of complex ores selectivity is achieved by chemical control and aggregation of particles of the same species is analogous to that; however, more work is necessary on ores for a better understanding of the pulp chemical aspects from the view point of selectivity in aggregation. For a few ores, the results of earlier workers confirm improved recoveries of fines by aggregation prior to flotation.

Jan 1, 1997

By R. L. Beatty

The Bond International Gold (BIG) Colosseum Gold Mine was discovered in 1865, but no recorded production occurred until the 1930&apos;s, with production approximately 19k9 (615 oz) of gold. The mine was closed in 1942 as a non-essential industry during World War II. The property was acquired by Dallhold Resources in mid 1986. Construction of a 1.1 million Mt carbon-in-pulp, cyanide mill started in November, 1986, and was completed in September, 1987. Minable reserves are estimated to be 9,560,831Mt (10,539,000St), with an average grade of 2.1 g/Mt (0.062 oz/st). This paper describes a general view of process flow and plant equipment, as well as a look at the maintenance and operational problems encountered in the fist six months of operation.

Jan 1, 1989

By A. R. Laplante

The mineralogy of the Joe Mann mine differs from that of other deposits of the Chibougamau area that are exploited by Les Nines Camchib Inc. It is characterized by very fine first generation gold and very coarse second generation electrum. Successful processing required adjustments of the processing flowsheet, which includes gravity, flotation, and cyanidation. A study of coarse gold liberation in the gravity/grinding circuit is described. Modifications to the flotation circuit and the reconditioning of a small capacity cyanidation circuit are presented.

Jan 1, 1989

By Brian E. Davies, Bobby G. Wixson

INTRODUCTION The impact of modern mining and ore processing on the environment is readily minimised. Our improving knowledge of how pollutants are released to and move through the environment has been accompanied by better expertise in controlling these emissions. For example, when the new mines and smelters were developed in the Viburnum Trend of Missouri a sulfur dioxide pollution problem was quickly recognized and soon controlled. (Wixson 1974) But older operations were not efficiently organized and, despite their smaller scale, they often caused major pollution problems. The British mining fields are among the world&apos;s oldest and during the heyday of their operation (approximately 1750-1900) they were worked with- out regard to their environmental impact. The Rivers Pollution Commissioners in the mid-nineteenth century were led to remark that ore dressing was carried on in a slovenly and wasteful manner and the complaints by farmers, that river borne mine wastes were poisoning both their crops and stock, were justified. (Frankland and Mortan, 1984). The Comissioners report led to the 1876 River Pollution Act of Parliament, the first modern environment protection legislation. The development of mining since the last century is characterized by improved regulation of the pollution potential of ore dressing, smelting and refining. The collective memory is unfortunately long and pessimistic. A serious problem arises when old mines are reopened especially if the mine has not been worked for several years since local action groups may soon blame the new owners for causing problems which, in reality, are longstanding and were caused by the use of earlier state of the art technology. It is therefore essential that during the early development stages prior to reopening that comprehensive studies be carried out to identify and quantify local contamination problems. These baseline studies should include surveys on the nature and composition of old tailings disposal areas and other wastes on the mine properties. The composition of air and water should be monitored. Soils are long term sinks for all heavy metals and particular attention should be paid to soils within any city areas near the mine since there are sources of heavy metals in urban areas which are not connected with mining and ore processing. This paper describes some of the results of such a study around a prospective cobalt mine in Southeastern Missouri. It is restricted to the soil survey of forest and agricultural land which took place in and around Fredericktown, Missouri. The city is located at approximately 37° 30&apos; North and 90° 20&apos; West and lies 143 kilometers south of St. Louis. There are several metal mines near Fredericktown, including Mine La Motte, which is the oldest and was first opened in 1720. [Figure 1] is a location map of the area. The survey described here was in connection to the reopening of the Madison Cobalt Mine which was first worked in 1947.

Jan 1, 1985

By R. L. Grayson

Compliance standards for respirable dust, which are reduced because of high quartz concentrations, have become an industry-wide problem. Research on the physical and chemical character of quartz-classified particles in respirable coalmine dusts indicates that they mine exist in intermixed layers or may be coated by clay or coal material. The relative amount of intermixing varies with the coal seam being mined. If most of the quartz particles of a mine dust are "pure," then the dust may have a high fibrogenic risk potential because of truly free silica and the compliance standard should be lowered. If, however, the quartz is locked inside another material matrix or coated, a reduced compliance standard may not be appropriate.

Jan 1, 1992

By M. R. Rosen

CARBINDER Polymer 498 is a liquid organic taconite binder which significantly improves fired compression in both fluxed and acid pellets. It has been used commercially in both shaft and straight grate furnaces. This new binder produces an unusual wicking phenomenon during balling wherein the rate of movement of interstitial water is accelerated to the surface of the balls. The phenomenon is proposed to be responsible for the significant improvement seen in fired compression. This paper presents information as to the effect of CARBINDER Polymer 498 on green ball and fired pellet properties. It also describes the wicking phenomenon and discusses a reversal in the normal balling operation procedures required for successful agglomeration.

Jan 1, 1988

By T. Y. Yan

An effective elution technique has been developed for recovering uranium from ion exchange resins loaded in the carbonate leaching process. The procedure employs direct elution with acid. In comparison with conventional base elution, the procedure yields eluate of higher uranium concentration, results in a more complete elution, keeps the performance of the ion exchange resin at the fresh stage, reduces acid consumption, eliminates carbonate consumption and reduces waste for disposal. The technique has been successfully demonstrated in the field and patented. It lends itself to commercialization.

Jan 1, 1988

By Kent G. Homewood

The well-being of any company is directly related to the well-being of its employees and to the effectiveness with which the personnel resource is managed. In an era when personnel management has steadily become more complex, there is an increased awareness of employee information systems at all levels of management due to: (1) regulations enacted by federal, state, and local government agencies; (2) technological advances within the mining industry which have resulted in the requirement for highly skilled personnel; (3) increasing concern for the confidentiality of employee information; and (4) management&apos;s need for information for planning purposes to control costs and for early recognition of trends and potential problems. In the past it was sufficient to maintain records manually. Today computers are necessary to provide information on short notice and effectively manipulate large volumes of&apos; data. This discussion will describe the following aspects of employee information systems: (1) collection and maintenance of information, and (2) applications which include employee health, salary administration, management re- sources, and labor negotiations.

Jan 1, 1979

By O. Lopez

"Stringent regulations and increased arsenic presence in ore bodies being exploited have created the need for cost effective and environmentally compliant technologies to remove selenium and arsenic from mine waters and metallurgical waste streams. Existing treatment methods have high life cycle costs and/or produce residues that, due to their unknown stability over the long-term, may represent future liabilities. This results in high compliance costs and uncertainties which negatively impact existing operations and projects in permitting. Selen-IX™ is a new ion exchange based process that selectively removes selenium from mine impacted waters down to 1 ppb while producing a stable inorganic iron-selenium product. Results of piloting completed on streams generated from coal and copper-gold deposits are presented along with preliminary equipment sizing and life cycle costs of full scale treatment. An example of a commercially available system for arsenic removal using sulphide precipitation is presented. The benefit of this treatment method is discussed based on recently completed technical feasibility assessment including laboratory testing and preliminary engineering design. INTRODUCTION Selenium Due to the chemical similarity between selenium and sulfur, selenium substitutes sulfur in many minerals that can be found in a wide range of deposits including coal, base metal, precious metal, phosphate, and uranium. One of the main environmental challenges facing the industry in North America today is related to the removal of hexavalent selenium, e.g. selenate, to ultralow levels, typically between 1 to 10 ppb, from large flows of often cold water containing less than 1,000 ppb of selenium. Recent studies commissioned by the industry identified biological selenium reduction systems as the best available technology. Although the biological selenium reduction process is commercially proven in certain applications to remove selenium to ultralow discharge levels, the technology has been primarily applied to relatively low and constant flows of warm water produced by the Flue Gas Desulfurization (FGD) scrubbers in the power generation industry. The wide spread adoption of this treatment method by the mining industry is hindered by high capital and operating costs associated with treating large flows of cold water, lack of data and knowledge about the long term stability of solid residues produced by this treatment, and limited capacity of biological systems to respond to sudden changes in flow and/or mass load of contaminants. Furthermore, it has been reported that reaching discharge limits less than 3 ppb could be a challenge and that polishing treatment for the removal of BOD and phosphate maybe required to avoid the impact of the biological treatment which requires organics and nutrients, on aquatic environment downstream of treatment plants. Alternate treatment systems are being developed to overcome and/or completely avoid some of the challenges of biological systems. One such treatment system is BioteQ’s Selen-IX™ process which is purely physico-chemical treatment system."

Jan 1, 2015

By J. N. Eskilsson, W. P. Chen, J. L. Kaplin, V. S. Romero

The Massachusetts Water Resources Authority is currently improving its primary water supply system for the Boston Metropolitan area. The improvements planned by the Authority, which provides water for 46 communities and over 2.5 million people in eastern Massachusetts, include the MetroWest Water Supply Tunnel (MWWST) to provide redundancy in the transmission system, a large capacity water treatment plant and extensive covered storage facilities. The 28.3 km (17.6 miles) long, mostly 4.3 m (14 ft.) I.D. MetroWest Water Supply Tunnel will allow repair of the aging Hultman Aqueduct, which for 56 years has served as the transmission main from the water supply reservoirs to Boston. On completion of the tunnel, the old pipeline aqueduct will be repaired and brought back into service as a parallel, redundant transmission main. This paper describes design considerations and the design process for pressure tunnels in general and the MWWST in particular. It provides an overview of how the design of pressure tunnel and shaft components progresses.

Jan 1, 1997

By Cristian Saavedra, Patricio Zarate

Flotation collectors play a crucial role in mineral flotation by selectively adhering to mineral surfaces and aiding in their separation from gangue material. They are heteropolar molecules, as defined by Sutherland and Wark (1955), featuring non-polar hydrocarbon chains and polar groups interacting with mineral surfaces to induce hydrophobicity selectively. The importance of collectors in mineral processing, as underscored by Lotter and Bradshaw (2010), lies in their ability to enhance recovery rates and improve selectivity, thereby optimizing the extraction of valuable minerals from complex ores. Collectors are classified based on their mechanism of action, as proposed by Laskowski (2010). This classification categorizes collectors into three groups: water-soluble compounds, water-insoluble “oily” collectors, and water-insoluble amphipathic compounds forming molecular films at the water/gas interface. This complements the chemical structure-based classification by Sutherland and Wark (1955) and Suoninen and Laajalehto (1993), offering a comprehensive understanding of collector diversity in flotation systems. Collector selection is an iterative process crucial for optimizing mineral processing efficiency, as emphasized by Lotter and Bradshaw (2010). Understanding the significance of collector mixing or synergy outcomes is paramount for enhancing mineral flotation efficiency and sustainability. Taguta, O’Connor, and McFadzean (2018) demonstrate that mixed collector systems enhance interaction enthalpies and microflotation recoveries, indicating improved performance. McFadzean, Castelyn, and O’Connor (2012), along with Critchley and Riaz (1991), delve into investigating synergistic interactions between collectors, offering insights for strategic selection. Observations from the study of collector synergy, as noted by Wakamatsu et al. (1980), reveal nuanced relationships surpassing individual collector behaviors. The methodology outlined in this paper provides valuable guidance for classifying and selecting collectors based on specific application needs, while also suggesting the potential for synergistically improving recovery across fine, intermediate, and coarse particles.

Feb 1, 2025

By Edward K. Davison

The so-called "construction aggregates," sand and gravel, crushed stone, and several kinds of metallurgical slags, are used principally in the construction and maintenance of all kinds of roads, engineering structures, buildings, homes, airports, etc. Production of these aggregates is approaching two billion tons annually. In terms of tonnage produced, sand and gravel has been the leading mineral since 1954, with crushed stone gradually approaching an equal tonnage. Sand and gravel is of widespread occurrence and of wide variation in suitable gradation and quality. It is a low-value, heavy-loading, short-haul commodity. These characteristics account for the historic concentration of production tonnage in and near urban areas where construction activities are concentrated. The combination of improved urban and near-urban highway systems and the steadily rising rail rates for short-haul traffic has fostered a consistent change since World War II from rail to truck transport, with trucks now accounting for more than 807 of the tonnage moving away from the production sites. While there are increasing numbers of exceptions, truck transport of sand and gravel is generally limited to about 30 miles. The expansion of the urban and near-urban areas of even moderate density, which became so pronounced after World War II, has been the source of most of the sand and gravel industry&apos;s environmental difficulties. Dust, noise and truck traffic associated with the operations -- particularly truck traffic -- have, of course, generated public complaint. This has been particularly true in those many cases where housing developments have approached and even surrounded sand and gravel operations which were in operation before the development started.

Jan 1, 1974

By Josh Savit

Corporate responsibility already encompasses safety and compliance. No longer will companies be able to use differing standards of care to miners based on the country in which they are working. This is not only an issue of social license, but one of global risk management.

By Marc Carriere

Bright-orange couplings adorning piping systems are a common sight in just about every underground mine in North America. Grooved mechanical piping, the pipe-joining system that utilizes these couplings, is the preferred method for joining underground and plant piping systems in the mining industry, due to the ease and speed of installation and maintenance. However, the applications for such systems have traditionally excluded high-pressure systems. Most grooved mechanical couplings have a moderate working-pressure limitation, so high-pressure systems have required the use of alternative joining methods, typically heavy-duty flanges. However, the introduction of high-pressure couplings (up to 4,000 psi) has made the grooved joining method viable, and even preferable, for backfill, deep-mine chilled water and dewatering lines and other high-pressure piping applications. As engineers explore the use of high-pressure couplings, questions will undoubtedly arise about the joining method?s capabilities. This article will address the capabilities and specifications of high-pressure couplings, and compare flanged and grooved mechanical pipe joining in traditional as well as high-pressure underground mining applications.

Jan 1, 2011

By Q. Xu, P. Somasundaran

Adsorption of nonionic/anionic surfactant mixtures on kaolinite has been studied, with •Sodium dodecylsulfate as the anionic surfactant, and •Octaethyleneglycol mono-n-dodecylether as the nonionic surfactant. Synergistic interaction between these surfactants was found to cause adsorption of the nonionic surfactant with its hydrophilic chains protruding into the bulk, leading to substantial changes in wettability and dispersion characteristics of kaolinite. Similarly, hydrophobicity changes are observed also for silica particles upon adsorption of nonionic ethoxylated alcohols owing to possible changes in the orientation of the adsorbed surfactant molecules at the interface.

Jan 1, 1993

Brace yourself-what used to be a 1 billion ton deposit is now a 1 Gt deposit. And that 1520-hp ball mill is now a 1.134-MW ball mill. Beginning with this issue, all engineering units and statistics in MINING ENGINEERING will be reported in SI units. The exception to this is the Technical Papers section, where units may still be reported by dual notation. For the past four years, ME has reported all units of measurement first in SI, followed in parentheses by the equivalent English value. This metrication policy, adopted by the SME-AIME Board of Directors in September 1975, was designed to aid magazine readers through a transitional period from English unit reporting to SI unit reporting. In October 1979, the SME-AIME Publications Board completed the English-to-SI transition by requesting the editorial staff, beginning February 1980, to report exclusively in SI. The Publications Board also requested the editors to prepare a chart of SI conversions useful to ME readers; this information follows on pages 156-157. The What and Wherefore of SI In 1960 the General Conference on Weights and Measures met in Sevres, France, and recommended that a new metric system-one that could uniformly cross all international borders-be adopted to replace all other metric systems. The outcome of this recommendation was the SI system of units, an abbreviation for le Systeme International d&apos;Unites (the International System of Units). It replaces the more familiar cgs (centimeter-gram-second) system and the m/ksA (meter-kilogram-second-Ampere) system. SI consists of seven base units, two supplementary units, and a number of derived units. Other units, called allowable units, may be used even though they are not part of SI. The seven base units are: meter (length); second (time); kilogram (mass); mole (amount of substance); kelvin (temperature); ampere (electric current); and candela (luminous intensity). The two supplementary units are radian, a measurement of plane angle, and steradian, a measurement of solid angle. Supplementary units can be used in combination with SI units, e.g., radiant intensity is expressed in W/sr, watts per steradian. Derived units are combinations of base and supplementary units. Velocity is expressed as meters per second (m/s), and acceleration as m/s&apos;. Using the relation established by Newton&apos;s second law of motion, force is expressed as kg-m/s2, more commonly known as the newton (N). Energy (work) is force times distance, expressed as kg-m/s2 and known as the joule (J). Power is work per unit time, expressed as kg, m2/s3 and known as the watt (W). Allowable units are the exception to the rule-they are not taken from base or supplementary units but, nevertheless, are used in the SI system. Volume units are normally expressed as the cubic measure of a length, such as cm 3. But a fluid volume of a cubic decimeter (dm3) is called a liter (L); the "L" is capitalized in another special SI rule to keep the lowercase "1" from being confused with a numeric "1". Other allowable units are degrees Celsius (°C) for temperature; and the minute (min), hour (h), day (d), and year (a) for time measurements. The prefixes in the table on the following page are used with SI units to express the magnitude of a measured quantity. A mill that processes 1000 tons of ore per day would be designated a 1 kt/d mill; a mine producing 10 million tons of ore per year would be called a 10 Mt/a mine. The rule here is to use prefixes that keep the value in a convenient range from 0.1 to 1000. In other words, it would be incorrect to write 25 000 kg-the prefix should be changed to indicate 25 Mt. One of the distinct advantages of SI is that it retains the decimal relation between multiples and submultiples of the base units for each physical quantity except for time. One more rule of SI syntax-numbers are separated into groups of three with a space between each group rather than a comma, e.g., 3,839,174 becomes 3 839 174. By the same token, a decimal number is also broken by spaces, e.g. 0.738153 is written as 0.738 153.

Jan 2, 1980

By Chulho C. Song, Liam Coleman

Alkaline pressure oxidation (POX) is an oxidative pre-treatment option that is commercially used for high-carbonate sulfidic gold ores. The high carbonate grades within the feed ore shifts the ideal operating pH to a basic regime. Compared with acidic POX, alkaline POX typically requires additional steam input due to a lower sulfur oxidation load and a high rate of in-situ carbon dioxide generation that needs to be vented along with steam. The cost of this steam addition is the largest differentiator between acid POX operation and alkaline POX from a cost comparison. However, alkaline POX can offset these costs through reduced acid usage for pre-acidulation and decreased alkali reagent consumption for subsequent neutralization. This paper reviews the specific operating cost impacts of acid/base consumption between alkaline and acidic POX with ores which require pre-acidulation, the overall economics of alkaline POX, and the regimes in which alkaline POX is economically favorable. The findings aim to guide industry professionals in making informed decisions for alkaline POX adoption by providing a summary view of its operational benefits and costs, contributing to the development of cost-effective and sustainable gold ore processing techniques.

Feb 1, 2025

By J. A. Brierley, R. Y. Wan

Newmont Gold has advantageously used the capabilities of mineral oxidizing bacteria to develop a process for the pretreatment of low-grade sulfidic and carbonaceous-sulfidic refractory gold ores. The biooxidation process results in the oxidation of the sulfidic minerals with increased exposure of gold for subsequent gold recovery. The biooxidized carbonaceous-sulfidic ores cannot be heap leached with cyanide because of the preg-robbing characteristics of the carbonaceous matter in the ores. Therefore, an alternative heapleach process using ammonium thiosulfate was developed to extract gold from these preg-robbing biooxidized ores. The ammonium thiosulfate leach process was successfully applied in both laboratory and pilot plant tests. Satisfactory test results were achieved, encouraging the continuation of process development.

Jan 1, 1998

By M. Kane, O&apos

BHP Iron Ore initiated research programs in January of 1995 to develop long term plans for decommissioning of the waste rock material at their Mt. Whaleback operation. More than 2 billion tonnes of waste rock were deposited during the past 30 years. Ultimately, the operators will deposit a total of approximately 5 billion tonnes in waste rock dumps constructed near the open pit. The Mt. Whaleback operation is located in a semi-arid climate adjacent to Newman, Western Australia, approximately 1200km north-northeast of Perth, Western Australia. The primary research program includes the development of technology for the long term performance of the waste rock dumps with respect to vegetation, slope stability, surface runoff, erosion, and water infiltration. This paper focuses on the design and implementation of a cover system to prevent water infiltration to the underlying waste rock. A laboratory program and the soil-atmosphere modelling completed to design the horizontal field test plots are described. The construction of the horizontal surface field test plots are discussed together with the field instruments installed to monitor performance. The key components of the instrumentation program are the design and installation of large scale field lysimeters to measure the unsaturated flow of moisture into the waste rock from the base of the cover layer. The cover system is designed to maximize infiltration during wet periods for subsequent evapo-transpiration while minimizing surface runoff. The result is a near zero net infiltration to the underlying waste material. A key feature of the design is the use of pit run waste material as the cover material. Monitoring is in progress and will continue for at least two annual wet/dry cycles. The optimum cover system should minimize the net infiltration of water to the underlying waste rock while maintaining physical and ecological integrity for long term performance.

Jan 1, 1998