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By S. K. Sharma

The Bureau of Mines' rapid method of dewatering fine-particulate slurries uses extremely high molecular weight polymers. These polymers form large, strong flocs which can be dewatered by sieving or sedimentation. However, sometimes these flocs deteriorate rapidly if water is not removed immediately. During field tests, clay slurries have been encountered that could have been dewatered economically if it were not for the rapid floc deterioration. A kinetics study was conducted to determine the rate of kaolin-PED floc degradation in which polymer addition, to bring the flocs back to their original condition, was used to determine the extent of floc decay. Results showed that the amount of polymer added, to replace polymer lost by spreading, was less for the lower PEO concentrations. For this clay-polymer system, floc breakage as judged by polymer additions followed first order kinetics. It was also found that the addition of fluoride ion stabilized the kaolin flocs.

Jan 1, 1992

By Shane Yanagisawa

The Mineral Creek Diversion Project is at the Asarco Ray Mine Complex, about128 km (80 miles) east of Phoenix, Arizona. The new tunnel will intercept the waters of Mineral Creek about 2,134 m (7,000 ft) upstream from an existing tunnel. The 5.74 m(18.83 ft) hard rock TBM will break into the old tunnel about 2,162 m (7,090 ft) in from the old portal after mining 3,888 m (12,753 ft). The TBM will mine through a series of igneous and metamorphic formations including volcanic tuff, soft volcanic ash, massive diabase, fractured quartzite, and schist. The TBM will hole through into the existing 4.88 m (16 ft) dia. horseshoe tunnel where the TBM will be disassembled and removed from the tunnel.

Jan 1, 2001

By R. D. Deister

The Buick concentrator represents state-of-the-art technology in automated digital process control operation utilizing a centralized computer. The process control strategies implemented at Buick are no longer new to the industry, but the successful application of these developments is still rather unique in North America. Productivity improvements, determined to be a direct result of the process control developments, are the primary topics of this paper. Emphasis is placed on metallurgical benefits including both lead and zinc recoveries; lead concentrate grade; and reductions realized in reagent consumptions, operating costs, and personnel. A detailed description of the concentrator, along with a history of the process control development and a more in-depth discussion of the control strategies implemented at Buick can be found in the references. (The Buick flowsheet is depicted in Fig. 1).

Jan 1, 1987

By Marc Lemieux

A new moving cone optimizing technique will be introduced. In order to facilitate under- standing of the moving cone optimizer, a re- view of the principles of moving cone design technique is presented. A concept called the negative moving cone design technique is also introduced to help facilitate understanding of the moving cone optimizing algorithm. In the introduction to Subsection 3.3, the relationship of the mineral inventory modeling technique to the ultimate pit design optimization methods was reviewed. Five modeling techniques were described, and four mathematically provable optimizing methods discussed. The broad use of the regular 3D fixed block model was attributed, in part, to its applicability to automatic optimization methods of pit limit design such as the Lerchs-Grossman graph theory algorithm, and in part, to its systematic nature.

Jan 1, 1979

By Kotaro Ohga, Gota DEGUCHI, Kiyoshi HGUCHI

The situation of Japanes coal mine is in the severe enviroment, because the policy on coal mining has changed. Every year one or two coal mines will be foced to close. To continue the production of coal, we have to reduce the cost of production. Therefore, the mining by longwall method which is more than 250m was attempted at Taiheiyou Coal Mine to reduce the cost and this mining method have had successful results. To get successful results by this mining method, the controlling and prediction of gas emission from the longwall panel will be most important things. In this paper, the comparison of the predicted gas emission from the mining panel based on the measured gas content by using new device with the observed results is described.

Jan 1, 1993

By M. J. Carlson

With the goal of improving the strength characteristics of pneumatically emplaced material used for localized subsidence control, the binding additives: fly ash, bentonite, and Portland Cement, were examined for their effect on the support capabilities of coal refuse. It was found that, within certain concentration ranges, all three of them offered some increase in the ultimate strength of the backfilling mixture; however, Portland Cement gave the greatest percentage increases. Selection of the appropriate backfilling mixture will allow for the most economical and efficient subsidence control when pneumatic stowing is employed.

Jan 1, 1987

By J. G. Pippenger

The Coteau Properties Company's Freedom Mine is a surface lignite mining operation utilizing large draglines, trucks and shovels, tractor-scrapers, and bulldozers to uncover a single coal seam. In 1989, a work order system was instituted to record data by equipment type, cost, productivity, and distance, and to provide historical information for planning the most efficient and economic use of each equipment type in the mining operation. This report explains how the work order system was initiated, what data is tracked, and how the data is utilized for equipment and project scheduling.

Jan 1, 1994

By Alan S. Peck

Chemisorbed oleate films on the surfaces of fluorite, barite, and calcite were studied by means of infrared spectrophotometry. Evidence is presented which indicates the mineral anions, i.e., fluoride, sulfate, and carbonate, are displaced from the mineral surfaces as a result of the adsorption from aqueous solutions. Also, chemisorption reactions between oleic acid and fluorite or calcite occurred spontaneously in the absence of water. Carbon dioxide was identified as a reaction product when dry calcite was contacted with oleic acid. There was no evidence of reaction between oleic acid and barite in the absence of water.

Jan 1, 1964

By Joyce A. Ober

Minerals for electronic and optical uses divide easily into two sections: 1) quartz and 2) minerals other than quartz. QUARTZ The properties of quartz crystal that make it useful for radio communications were discovered in 1918. Since that time, an in¬dustry for the mining and processing of natural quartz crystal has grown, matured, and been almost entirely replaced by new tech¬nology. The new technology still involves quartz crystal, but ma¬terial that is grown rather than mined. An economic summary of the commercial growing of quartz crystals has a place in a handbook directed to the mineral engi¬neering industry because quartz crystals have long been an impor¬tant commercial mineral, and the raw material for cultured quartz - ¬that is to say, quartz crystals grown through the ingenuity of man - is still natural quartz. Nearly all the natural crystals that have been used for elec¬tronics and optics came from Brazil. The larger pieces which met rigorous standards of quality were used for electronic and, to a lesser extent, optical components. Smaller pieces and fragments were used for vitreous silica. The need for high quality material in quantity led to US government sponsored research and exploration programs in the 1940s. No deposits meeting the very rigid requirements for electronic-grade quartz were found, but other projects resulted in the development of a process for the factory growth of beautiful crystals of prescribed shape, size, and quality. Domestic deposits of appropriate quality were identified to use as raw materials for the quartz culturing process. The development of the cultured quartz crystal illustrates the success that technology can have in adapting a product of the mine to increasingly sophisticated uses. A remarkable achievement per¬haps, but foreshadowed by experiments by Giorgio Spezia (1908), an Italian geologist studying the relative effects of temperature and alkaline environment on the solubility of quartz. Modem radio equipment is most often controlled as to fre¬quency by the presence in the circuit of a separately added crystal¬ - the 1918 discovery responsible for the existence and growth of the quartz industry. The crystal is quartz, but this component is a carefully oriented and prepared slice from a crystal, but not a crystal as recognized by a rock hound or seen in a museum. How quartz operates to control frequencies is not a proper subject for a handbook on industrial minerals, and references should be consulted (Cady, 1964, Mason, 1964). Quartz belongs to a class of materials called dielectrics: those that do not conduct an electric current but permit electric fields to exist and act across them. Quartz shows the piezoelectric effect, which means that when a quartz plate is mechanically deformed against its natural stiffness, one of its surfaces becomes negatively charged, the other positively charged. When the plate is released quickly from the stress, the charges disappear as the plate regains its original shape, but because of mechanical momentum the plate deforms in the opposite direction (to a lesser amount) and the surfaces correspondingly become charged in the opposite direction. By thinly coating the two surfaces with metal and attaching flexible wires, these charges can be brought into an electronic circuit. If the surfaces are suddenly electrically charged by movement of current through the wires, the converse piezoelectric effect occurs and the plate deforms. Carry the thought further and it is realized that an alternating current flowing through the wires responds to the mechanical oscillation. By controlling the thickness of the plate, its mechanical vibration frequency can be varied through a wide range. One type of quartz plate, the AT-cut, has a precisely defined orientation with respect to the crystallographic axes of the crystal and vibrates on a microscopic scale much as a book would deform when placed flat on a table and the top cover moved parallel back and forth with the hand. At least 17 other orientations have been studied, some of which have preferred uses in various applications (Cady, 1964). The quartz crystal industry is composed of three main segments (excluding fused quartz and quartz used for optical purposes): 1. Natural electronic-grade quartz crystals. Mined quartz suitable for fabrication into piezoelectric units. Zlobik (1981a) esti¬mated the waste to ore ratio at 1:1000 to 1000 000, depending upon the deposit. 2. Lasca. Mined quartz usable as feedstock in the production of cultured quartz. Approximately 0.63 kg of lasca are required to produce 0.45 kg of cultured quartz. 3. Cultured quartz. Cultured quartz is produced from lasca feed¬stock in a process of crystal growth in an autoclave under conditions of heat, pressure, and time. It is estimated that 0.45 kg of cultured quartz is equivalent to 1.4 to 4.5 kg of natural quartz crystal in yield of commercial quartz suitable for slicing into piezoelectric units. The chronology of the development of the quartz crystal industry both natural and cultured follows: Date Comment 1918 Discovery of the piezoelectric effects of quartz crystal 1921 Application of the piezoelectric effects of quartz crystal in the circuitry of radios 1948 Establishment of a quartz crystal commodity stockpile by the US Government 1952 US consumption of natural quartz crystal at an all time high of 228 t 1958 First commercial production of cultured quartz crystal 1970 Cultured quartz crystal production exceeds imports of nat¬ural quartz crystal 1971 Cultured quartz crystal consumption surpasses natural quartz crystal consumption

Jan 1, 1994

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 Arthur M. Ribe

In my experience, nothing helps me better to get off to a good start in preparing a paper or a talk than a copious consultation with a comprehensive dictionary. I also feel defining the perimeters of a particular subject is helpful to the listener and reader. Sometimes thus precisely defining even the most common of words is helpful. Our general topic this morning as all of you know is "Transportation of Industrial Minerals." The definition of transportation given by the dictionary which I think is appropriate here is: "Systems and modes of conveyance of persons or goods from place to place." Our preceding panelists have outlined for you the state of the art inso¬far as systems and modes of conveyance from place to place are concerned today via rail, water and motor. My assignment is somewhat different as indicated by my topic, "The Traffic Manager in an Industrial Minerals Operation."

Jan 1, 1969

By L. J. Jansen

Techniques utilized to incorporate geological data in computer modeling and ore reserve estimation have undergone considerable evolution during the past fifteen years. Computer analysis and evaluation of two precious metal deposits are presented as examples of innovative computer techniques developed at Asarco. The first is a gold deposit occurring in a steeply dipping Pre-Cambrian greenstone sequence. The second is a manto-like manganiferous silver deposit occurring in a relatively flat sequence of Late-Paleozoic sediments. In both deposits, four sub-horizontal zones of geological influence are evaluated.

Jan 1, 1985

By Arthur A. Brant

Your chairman has asked me to deal with questions of education relative to our present and projected trends in the field of mineral expiration. First comes our definition of education--and education is not the merely formal acquiring of academic knowledge, but the understanding, using and projection of knowledge into our channels of life and thought activity. This past year makes us realize the extent to which price and economic cut-off may stimulate or curtail exploration,, But exploration does not consist solely in the discovery of sources of material. There is just as inspiring and imaginative a territory in the develop¬ment of uses and application--and no one in our base metal industry but would hope that our educational processes would fertilize those springs of inspiration that lie dormant in us all, toward the- imaginative conception of new uses--lead roofing cloths or felts, non-tarnishable copper utensils, further zinc solid state application. Thus an educational pattern should seek to develop imagination and thinking beyond--the possibility of that small but oh so difficult step just ahead of the existing,

Jan 1, 1959

By Kevin Sierra, Orfelinda Avalo, Julio Guizado, Edwilde Yoplac, David Martinez

Mining tailings are slurry byproducts of mineral recovery. They generate serious environmental risks due to their toxicity when exposed to water and oxygen. Studies focus on eco-friendly alternatives for mitigating these environmental impacts. Processing these tailings enables a sustainable mineral production model through circular economy practices. This study evaluates using gold mining tailings to recover gold and produce bricks. Flotation tests obtained a concentrate with 86.66% gold recovery, containing sulfides (pyrite, arsenopyrite) and a tailing with silicates and oxides suitable for brick manufacturing and ornamental pieces. This approach promotes eco-friendly solutions and a greener approach to mining operations.

Feb 1, 2024

By A. T. Yu

The quest for ore in an open pit is fundamentally an earth moving proposition. This thesis is vividly underscored by the rapidly increasing volume of waste to be removed in newer mines, where in some instances waste to ore ratios have reached as high as 20 to 1. Continuing depletion of high grade reserves, greater demand for raw materials, coupled with ever climbing labor costs, have made the problem still more pronounced and the need for more effective means of earth moving in an open pit even more acute. A conservative approach to the problem has been to upgrade the sizes of conventional earth moving equipment such as shovels and trucks. In many open pits, particularly in the C.S., this has been responsible for the generally down- ward trend of earth moving costs. None the less, the investment costs of these machines are high, and their gigantic engines are seldom fully utilized. Moreover, a large number of operators are required and maintenance remains relatively high. Unfortunately most people have felt that no other viable alternative was in sight within today's technological capabilities.

Jan 1, 1973

By Scott W. Beckman, Leslie C. Thompson, Joseph A. Kizis

Heap leaching of ore with cyanide is a common and economical means of extracting precious metals (gold and silver) from mined ore. The use of cyanide, and the heap leach process, can seriously impact the environment. In the worst case, catastrophic failure of containment structures can release toxic levels of cyanide into receiving bodies of water, resulting in toxicity to ecological communities and contamination of public water supplies. Furthermore, cyanide degradation products such as nitrates can also impact local streams, lakes, and aquifers. Even if cyanide can be removed, the crushed residual ore may generate acid solutions that can release toxic heavy metals into the environment. Pintail Systems, Inc. (Pintail) of Aurora, CO, in conjunction with technology partners Science Applications International Corporation (SAIC) and Fairmile Gold Corporation (Fairmile), have developed a microbially-based precious metal lixiviant that can be used as an alternative to cyanide. The microbial process, called BioLix, is Pintail's second-generation biotechnology product for the recovery of precious metals from ore. The BioLix process is based on the enzymatic induction of organic lixiviant compounds using proprietary inducing agents and microorganisms. The process operates at near neutral pH and ambient temperatures using non-pathogenic microorganisms and food-grade chemicals. Precious metal extraction is also enhanced through the employment of microorganisms that facilitate mineral-solution reactions such as surfactant generation (improved wettability), and oxidation of gangue minerals that expose mineral surfaces to leaching. In order to demonstrate the effectiveness of the BioLix process, results from laboratory bench-scale experiments and a column study are presented. In addition, new applications for this enabling technology are discussed and include re-leaching of spent ore heaps, in situ leaching, and cyanide replacement for heap leaching.

Jan 1, 2000

By M. Cambridge

During the latter part of the twentieth century exploitation of mineral resources, and gold mining in particular, experienced a resurgence in Europe, with major mining houses and many junior companies involved in exploration and subsequent mine development. Gold projects in particular were actively encouraged and exploration programmes and permitting studies initiated in more than 15 countries, both within the European Union (EU) and the former eastern bloc. During the initial period, governments in many countries provided active support. Following a series of negative environmental mining incidents in the latter part of the century public opinion, often ill-informed, led to political pressure to withdraw governmental assistance. This in turn resulted in the revocation of exploration licenses, and ultimately to the failure to develop a number of potentially world-class mines within the region. Despite these setbacks, gold production in Europe continues, and is probably higher now than 20 years ago. The mining industry is currently coming to terms with both changing attitudes of governments, and the increase in scope and prescriptive nature of legislation. Recent experiences, particularly in Greece and Turkey, exemplify the problems faced by the industry in the region, which are causing major mining companies to reconsider future activities in Europe. The paper presents an overview of European gold mining and its environmental performance in the context of international practice, new legislation, and public perception of mining generally. The rationale of governments in withdrawing support for the industry is questioned, and the feasibility of achieving sustainability where there is no level playing field globally is reviewed. The question is posed to governments, regulators and mining companies alike as to whether there is a future, not only for gold mining, but for the minerals industry in general, within the EU.

Jan 1, 2003

By W. N. Key, L. C. Acton

Freeport Minerals Co.'s Ertsberg East underground operation typifies the cliche that all the "easy" ore deposits have already been found. Despite its location, in a remote Indonesian rain forest, and the effort and expense required to develop the ore body, the mine was developed on schedule, under budget, and with minimal disruption of the adjacent open-pit mining operation. Development of the Ertsberg East copper, gold, and silver ore body took less than two years after exploration drilling and feasibility studies were completed. In addition, the project came in well under its targeted budget of $101.5 million. Initial block caving and underground ore production took place last year. About 3 kt/d of Ertsberg's total 8.6 kt/d ore production is currently mined underground. This will increase to 5.4 kt/d by year's end. Underground operations will eventually account for all of Ertsberg's production, as the open-pit ore body is depleted. Freeport Minerals is currently studying the possibility of increasing total Ertsberg East production tonnage to 10.5 kt/d by 1983. The equipment, work practices, and development methods at Ertsberg East (Gunung Bijih Timur or "GBT"), while typical of other block caving mines, were modified for rapid mine development and maximum ore recovery. Located in the Irian Jaya province, "Gunung Bijih" is the Indonesian expression for the Dutch "Ertsberg" that in English means "ore mountain." "Timur" means "east" and relates to the fact that the new underground ore body lies about 1 km east of the open pit. The area surrounding GBT is mountainous, with peaks from 4.2-5 km. The underground mine adit and surface plant are located at a 3.6-km elevation. The mine, 4° south of the equator, gets 5.1 m/a of rain, but has an average daily temperature of only 13°C because of the mine's elevation.

Jan 7, 1981

By Walter E. Jaworski, William R. Beloff, John Dunnicliff

As a step in the endeavor to reduce future tunneling costs in New York City, the Environmental Protection Administration, Dept. of Water Resources, instituted a program in 1972 to monitor the performance of the lining of one of its tunnels. A monitoring program was included as part of the contract specifications for the East Branch Interceptor Sewer tunnel for the Port Richmond Water Pollution Control Project in the hope that measured data would indicate possible future cost effective design or construction improvements. The monitoring program involved measuring ground deformations, circumferential liner stresses, longitudinal liner stresses, and jacking pressures. This paper presents some of the findings from these measurements, with emphasis on liner stresses. PROJECT DESCRIPTION The 3.05m (10 ft) diameter steel lined tunnel was constructed under two separate contracts. The easterly portion, Contract 3A, was approximately 3109m (10,200 ft) in length and constructed by Peter Kiewit Sons Co.1 The westerly portion, Contract 3B, was approximately 2160m (7100 ft) in length, and constructed by Richmond Constructors, a joint venture of Grow Tunneling Corp., MacLean Grove & Company, Inc., Grove, Shepherd. Wilson & Kruge, Inc., Morrison-Knudsen Company, Inc., and Andrew Catapano Co., Inc. Each contract included three test stations, hence a total of six along the tunnel route. Excavated material along the tunnel route consisted primarily of dense fine to coarse sand with varying percentages of gravel and silt with occasional boulders. Pockets of organic silt were encountered on Contract 3B and a large portion of Contract 3A ran through slightly weathered serpentine and schist. Overlying material and the groundwater level varied considerably along the route as did the height of overburden. Figures 1 and 2 show the generalized soil profiles for Contracts 3A (PK stations) and 3B (RC stations) respectively.

Jan 1, 1979

The use of controlled recirculation can be dated back to the early 1930s. Although this method has been applied in many mines since then, a generalized comprehensive network analysis is still lacking. This paper presents a unique approach in which the ventilation network with a controlled district recirculation is divided into two subsystems: a main subsystem and a recirculation subsystem. The subsystems are analyzed individually and the results and their relationships are then integrated into discussions of the total ventilation system. The analysis of the recirculation subsystem is facilitated by introducing a non-dimensional parameter A, which represents the ratio of the air quantity for the working face to that for the subsystem. As a result, fan and regulator pressures and air power for various recirculation arrangements can be effectively expressed as a function of A and the subsystem air quantity. Numerical examples are included.

Jan 1, 1995