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By Dennis W. Leonard

Let us begin our discussion by looking at historical and current levels of sales of both natural and synthetic zeolites on a world-wide basis. Due to the understandable reluctance of some companies to disclose sales data, some estimation has been necessary regarding the tonnages and values shown in Table 1. We are confident, however, that they are within acceptable limits, especially the numbers referring to natural zeolite.

Jan 1, 1979

By Entov Vladimir M., Gilmer R. Burgos, Andreas N. Alexandrou

"Processing of metal alloys in their mushy state represents a new trend in metal processing. As part of this process, known also as thixocasting, a specially prepared slurry at a temperature in the mushy region is injected into a die. Parts produced using this technology offer better mechanical properties than those produced by casting, and comparable to those of forged alloys.In thixocasting, semisolid slurries are highly concentrated suspensions of rounded rosette-like crystals in eutectic liquid. The mechanical behavior of the slurry is determined by the structure and properties of the skeleton formed by the alpha phase particles. The skeleton structure is almost never at equilibrium, and its evolution is, governed by a number of kinetic phenomena of different c11'aracteristic time-scales. Therefore, the skeleton structure depends on the mechanical and thermal history of the material. As a result of these kinetic processes, the rheological properties of the material, such as effective viscosity and yield stress, decrease with structure breakdown, and increase with its development. In the present investigation, the behavior of semisolid slurries during processing is modeled using the conservation equations, and a Herschel-Bulkley fluid model. The rheological parameters are assumed to be functions of the solid volume fraction, and of a structural parameter that changes with processing history. The evolution of the structural parameter is described by a first order kinetic differential equation that relates the rate of build-up and break-down of the solid"

Jan 1, 2000

By C. M. Signer, W. P. Hewitt

THIS is a story of a mine discovered in the days of the Conquistadores but that remained unimportant until the second decade of this century. Without the usual legendary history of romance and fabulous riches it has become famous for the development of unexpected metals and unusual problems. These developments and experiences, exciting and interesting as any legend, are the substance of the San Antonio mine of the Santa Eulalia district in northern Mexico. Originally opened for its silver-lead content, it developed a tin deposit of singular economic importance and unique geologic interest, a vanadium orebody that for a few years placed it among the leading vanadium producers of the world, and now lead and zinc sulphide ores. It has been the seem of a disastrous flood that brought deep-sea divers into Mexico's desert mountains and raised important problems regarding ground water, demanding unusual measures. Geology and operating questions relating to the above matters will be discussed and much of it is recent history which has become a part of Mexican mining lore. History Dates Back to 1325 Santa Eulalia is the oldest of American cities, founded in 1325 by the Aztecs under the name of Tenochtitlan and devastated in 1521 by Cortes and his rapacious band of iron-willed adventurers. Their lust for gold burned through the Aztec empire and onward into most of North America. Santa Eulalia was in the path of conquest. In 1591 the district's first ore discovery was made near what is now the San Antonio mine. The ores carried no gold and the silver-lead content was unattractive to the early pioneers. Not until 1700 was real mining activity undertaken.

Jan 1, 1952

By Onwukamike, Onyedika G. O, Ogwuegbu M. O. C., K., Onyenehide C

A detailed mineralogical and elemental characterization of a lead (Pb) ore deposit from Ishiagu, Ebonyi State, Nigeria was carried out with XRD, SEM-EDX, and ICP-OES based mappingtechniques. The results show that the most dominant and valuable metal is lead (Pb = 95.02%, mass fraction). The main mineral is galena. Ilmenite and sphalerite occur as minors, which account for 2.71% and 0.80% respectively. Elements like Al, Ca, Mg, Ti, Na, Mn, Si and Sn occurred in trace amounts and are disseminated in the entire ore body.The surface and interrelations of the crystals were examined with x-ray mapping and the result shows the pattern of dissemination of the minerals within the ore body.

Jan 1, 2015

By C. Jay Hodgson, P. J. MacGeehan

"Of the 135 current or past-producing 'gold-only' mines in the Superior Province of the Canadian Shield which have produced more than 100,000 tons of ore, the 33 mines which have produced one million ounces or more of gold have accounted for over 84o/o of the total production of 137 million ounces. The published literature on these 33 deposits was reviewed in order to determine the geological setting of the mineralization on a regional (mining camp) and local (mine) scale. The dominant rock types underlying the mining camps are mafic, variolitic, tholeiitic volcanic rocks with a significant ultramafic (komatiitic) component, and clastic and/ or exhalative sedimentary rocks. Felsic volcanic rocks are generally subordinate. Most mining camps are located at or near the top of the mafic-ultramafic sequence, and generally there is a major sedimentary-volcanic contact present which may be 1) a stratigraphic superposition of volcanic and sedimentary units, 2) a rapid, along-strike gradation from dominantly volcanic to dominantly sedimentary units due to facies change, or to the formation of structurally controlled sedimentary basins during volcanism, or 3) frequently (at 40o/o of the camps) a juxtaposition of sedimentary and volcanic sequences across a major fault zone or 'break', which in many instances may represent a reactivated, syn-volcanic basin-margin fault.In contrast to the regional setting, on a local or mine scale over 90o/o of the 33 mines contain felsic intrusions and/ or extrusions within mine workings. The felsic rocks may be quartzbearing (commonly quartz-feldspar porphyries) or dominantly quartz-free (commonly feldspar porphyry syenites or monzonites), and appear to have been emplaced in two different depth-zone environments: an epizonal intrusive environment, and a volcanic vent environment. Although the distinction between epizonal intrusive and volcanic intrusive-extrusive rocks is uncertain in many deposits, the two are tentatively separated on the basis of the grain size of the rock matrix (medium to coarse grained vs aphanitic to fine grained), homogeneity (multi-phased and/ or compositionally zoned vs compositionally homogeneous), and the shape and relationship to stratigraphy of the igneous body (circular or oval in cross section, and cutting the stratigraphy at a low angle vs lenticular and either stratiform or cutting the stratigraphy at a high angle). In addition, felsic intrusions of the volcanic environment commonly grade into tuffs or breccias of extrusive origin, whereas epizonal intrusions do not.Stratiform ore zones of possible exhalative sedimentary origin appear to be confined to deposits in which volcanic felsic rocks are present, and are absent from deposits in which only epizonal felsic intrusions are present. Pervasive carbonate- rich alteration, commonly in roughly stratabound zones of regional extent, and carbonate-rich chemical sedimentary rocks are present in over three-quarters of the deposits containing quartz-bearing felsic volcanic rocks, but are much less common in deposits with quartz-free felsic volcanic rocks. The host sequences of epizonal felsic intrusions which are quartzfree are more commonly sedimentary than those of quartz-bearing epizonal felsic intrusions.Quartz, carbonate minerals, arsenopyrite, scheelite, tourmaline and Cr-muscovite ('juchsite') are the most common mineralogical associates of gold. Arsenopyrite is essentially restricted to the volcanic environment, occurring in about twothirds of the deposits with quartz-bearing felsic volcanic rocks and less than half of the deposits with quartz-free volcanic rocks. Tourmaline, on the other hand, is almost ubiquitous in deposits associated with epizonal intrusions and also occurs in about two-thirds of the deposits associated with quartz-bearing felsic volcanic rocks, but in only one of the eight deposits associated with quartz-free felsic volcanic rocks. Scheelite is essentially restricted to ores of quartz-rich fel"

Jan 1, 1982

By Guthrie. R. K., H. B. Hill

"INTRODUCTION During the early 1920's world-wide attention was attracted to a group of oil fields (Mexia, Wortham, Currie, Richard, and Powell) later known as Mexia-Powell fault-line fields in Limestone, Freestonne, and Navarro Counties, Tex. Enormous yields of high-gravity oil from the wells in these fields resulted in drilling campaigns that quickly surpassed all previous records for rapid, intensive development of productive areas. The discovery of oil in the Mexia filed in September 1921 was followed quickly by the finding of oil in the Currie field in October. In January 1923 oil was discovered in the Powell field; in February 1924 the Richland field, midway between Currie and Powell fields, was brought in; and in November 1924 oil was discovered in the Wortham field, situated between Mexia and Currie fields. Each of the fileds was developed rapidly: wells were spaced closely and had high initial production; production peaks were reached early in the producing lives of the fields; subsequent decline was rapid, and there was early and rapid encroachment of edge water.In 1927 Bureau of Mines engineers, in their investigations a engineering conditions in oil,completed a preliminary study and published a mimeographed report 4/ on underground conditions in the Wortham field, and in 1928 they reported on production and development problems in the Powell Field. 5/ field."

Aug 1, 1943

By R. W. Nice

Presently about 60% of the world's nickel resources are tied up with lateritic ores while about 25% of the world's nickel is produced from sulphides. Based on this the industry has to focus on improving lateritic nickel economics in order to maintain the high use of the metal worldwide. In 1997 three junior mining companies in Australia organised finance against all odds and commenced development of three separate nickel and cobalt extraction plants treating lateritic nickel ores. All three projects utilise similar pressure acid leaching (PAL) technologies while each has unique metal recovery technologies All projects have experienced numerous processing and maintenance related difficulties such that full ore throughput has been reached by only one operation after five years. This shortfall in performance has caused the owners considerable angst and financial pain. In 2000 Cawse went into receivership and was purchased by an international corporation. Recently, Bulong also went into receivership and has undergone an orderly shutdown, awaiting sale to a new buyer. Murrin Murrin has settled with its financiers and is in a position to operate as planned for many years forward. This paper will discuss a number of the technical difficulties that affect the ore preparation, PAL and solution treatment circuits of these plants. The objective is to identify the cause of some of the difficulties and propose possible solutions so that the next generation of lateritic operations can emerge as technically and, more importantly, economic successes. A number of these process improvements have been identified by the existing operators and in many instances have been or are being implemented into the existing operations.

Jan 1, 2004

By Glenn D. Lyle

As part of an initiative to improve value in mining, CEMI is developing a handbook on best practice in mine design. Various formats were examined, and of these, the wiki was selected as being most suitable. Being web-based, its global reach and capability of being continuously updated allows the wiki to evolve as new knowledge is generated, and to capture the diversity of experience of practitioners in the mining industry. While wikis have many advantages in terms of organizing content and searching, their ability to be edited by users is often seen as a negative characteristic for quality control. To ensure reliability of information content, author attribution, specific authorship models, and a peer review process have been implemented, in addition to the standard version tracking capability of wikis. The first phase of the project concentrates on topics related to underground hard rock mine design. The scope will be expanded to cover other aspects of mining as the project matures. Strategic partnerships with various organizations, such as the CIM, and CANMET, are being formed to provide a wide range of seed material to stimulate growth of the site. www.minedesignwiki.org

May 1, 2011

By Dale R. Andrus

Why is there such an increased thrust toward positive multiple use land management and where will it lead? History and purpose of the mining law of 1872. John Marshall discovered gold at Sutter?s mill near Coloma, California, on January 19, 1848, and utter chaos resulted. The great migration of people to the undeveloped western lands had begun. Prior to this discovery, copper, lead, and iron had been the minerals for which the laws were made. With this discovery of gold on the public domain, it became apparent that congressional legislation was necessary. This became even more apparent as each of the numerous mining districts which were springing up in California, and elsewhere in the west adopted local miners' customs to regulate their activities. Although these early miners acted under mining district rules and in some cases state regulations, they were, in reality, appropriating minerals without sanction of federal law.

Jan 1, 1970

Thank you for the opportunity to speak at this important conference attended by aspiring mining professionals, some of whom will become the leaders of the mineral resources industry that forms the solid foundation of AustraliaÆs past and that will fuel the exciting growth of AustraliaÆs future.I want to briefly touch on the history of our business, then look at the opportunities that exist in the contract mining industry and finally comment on what the educators need to consider in their curriculum to meet the needs of our business. Byrnecut started out as an idea in early-1987 developed by a group of four mining people. At the time the industry was on the high end of a mining boom, the era of the Bonds, Connels, Skases and so on. Riding on this wave of euphoria we borrowed $600 000 from the National Australia Bank and, without having enough knowledge to lose sleep over the potential risks, started business in mid-1987. The euphoria quickly evaporated with the 1987 October stock market crash. The bank pulled our overdraft, equipment finance rates increased to over 20 per cent per annum and my house was mortgagedseveral times over. The business learning curve was extreme for a young mining engineer who had developed his trade in the relatively sheltered environment of a large public mining house, namely WMC. We were somewhat bitter that the banks had done a runner. We were a private company, backing the business with personal assets with our shoulders to the wheel, whilst the Bonds of the world had theirnoses in the trough ripping off mum and dad shareholders. All of this had a sobering effect, namely keep your feet on the ground, stick to the knitting, work hard and worship cash flow. Since that stressful but adrenaline pumping beginning the company now employs over 600 people and is now working for major mining houses at over a dozen locations in Australia, east Africa and WesternEurope and the National bank is again our banker. On this basis I consider myself qualified for the subject of this speech.

Jan 1, 2002

E. A. H. Tays, San Blas, Sinaloa, Mex. (communication to the Secretary*):—The results obtained by Messrs. Hofman and Hayward in their experiments, proving that a low percentage of copper sulphate with a variable percentage of salt, depending on the ore, gives the best results, confirm practical mill-work which I did in 1895. I have none of my notes, taken at the time, to refer to, so have to rely solely on memory, which precludes the conciseness that is alway desirable. In 1894 I took charge of the plant of the San Rafael Company, near Chinipas, Chihuahua, Mex., which at that time was treating a very refractory ore carrying about $15 in gold and from 20 to 25 oz. of silver per ton, the bullion being about 300 fine in gold. The silver in the ore was in the form of a sulphide. Although carrying an average of 0.75 oz. of gold per ton, free gold could rarely be seen by panning, but upon roasting a sample of the ore the gold became visible at once—a result which was discovered by chance and used to advantage later. In order to utilize the old mill to the best advantage, it was decided to use pan-amalgamation after roasting. The roasting, done in a lime-kiln, was similar to the ordinary " burning " operation. The roasted ore was trammed to the mill-bins and crushed by 10 stamps to pass a 30-mesh screen. The pulp was de-watered and fed to four 1-ton pans. My recollection is that upon starting the mill-work, the charge contained 1.5 lb. of copper sulphate and 5 per cent. of salt per ton. From the start the extraction was unsatisfactory and the loss of quicksilver was very large. Experiments were then carried out on a working scale. First, the quantity of copper sulphate was increased 4 oz. at a time; then it was reduced

Jan 1, 1910

By T. Crivits

"Freeze lining technologies are used industrially to protect the integrity of furnace walls in pyrometallurgical reactors. This is achieved by solidifying a protective layer of slag on the inner furnace wall. In the current study, laboratory experiments have been undertaken to produce freeze linings in ‘Cu2232 O’-‘FeO’-MgO-SiO slags under controlled conditions using an air-cooled probe technique. Whilst most thermal models of freeze linings have assumed the freeze lining-bath interface to be at the liquidus temperature of the bulk bath and to be planar in geometry, the current research has demonstrated that this is not the case. Experiments undertaken using this high-temperature slag system have shown the interface at steady state conditions to be at subliquidus temperatures. The solid phases present at the interface do not include the primary phase and the interface is non-planar. The study indicates the need for improved understanding of the fundamentals of freeze lining formation, and of the influence of system properties and process parameters"

Jan 1, 2015

Jan 1, 1992

The 1990s present many challenges, not the least of which is in the area of health and safety. Integrating of safety and health into the management process to suit the overall needs of a company will require commitment. Organisations which consistently perform to high success levels do so because they plan it that way. By using tools of total quality management, the potential to continually improve all safety processes exists. The successful integration of total quality measurement principles used in the improvement of safety processes, and the measurement of performance-based activities allow for prevention of accident causing scenarios and performance improvement.

Jan 1, 1993

By R. V. Typliski, G. J. Labarre

"Hudson Bay Mining and Smelting Co., Limited, Flin Flon, Manitoba, Canada, has developed a metallurgical wastewater treatment system employing two-stage lime neutralization, sludge recirculation and conventional mechanical thickening.Laboratory investigations, initiated in 1970, led to the construction of a pilot-scale minewater treatment plant, at Schist Lake Mine, in early 1971. This plant, treating 600 cubic meters/day wastewater containing 30-60 mg/l zinc, demonstrated metal extraction efficiencies of 99% under normal operating conditions.On the basis of this pilot work, a second pilot-scale treatment system was established in 1975 at the Flin Flon metallurgical plant to treat zinc refinery process waste water. Through numerous improvements, including automatic control equipment, the system has evolved to a full-scale operation capable of treating 800 cubic meters/ day wastewater containing 4-11 gm/l zinc. Treated effluent contains 0.2-20 mgll zinc. Hydroxide sludge produced returns to the metallurgical process for recovery of metals while clarified effluent discharges to waste.With the system, Hudson Bay Mining has achieved its original goal: the reduction of environmental contamination, while realizing ii return from metal recovery."

Jan 1, 1980

By John J. Sammarco

"The mining industry has made great strides in making mining safer and reducing the occurrence of mine disasters. Nevertheless, sometimes miners encounter smoke while trying to escape from a mine. Underground miners use different visual cues to help them escape from a smoke-filled environment. Foremost, miners look for primary and secondary escapeways that are typically indicated with reflective markers of various colors, with at least 11 colors available from manufacturers. Federal regulations require that escapeways be marked, but they do not specify the colors to be used. Thus, no standard color code exists and some colors can be more difficult to see in a smoke-filled mine.Researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) tackled this problem by taking a human-centered approach to provide miners with better visual information that would improve their ability to see escapeway markers in smoke, thus enhancing their ability to self-escape. What marker colors does your mine use?Does your mine use blue retro-reflective markers to indicate primary or secondary escapeways? Is your mine ready to purchase new or replacement retro-reflective markers? Color is important and blue had the poorest visibility as determined by OMSHR’s recent research investigating the visibility of markers in smoke. OMSHR researchers are not alone in their interest to improve a miner’s ability to escape - specifically when their efforts are hampered by smoke. For instance, there is a LinkedIn Mining Safety subgroup called "Standardized Color Code for Escape Ways and Returns in Underground Mines," and a recent National Academy of Sciences report recommended the development of humancentered technologies to enhance self-escape from underground mines. The mining industry has a common goal of helping improve miner safety, especially when it can be done by way of a simple and relatively low-cost solution of using escapeway colors that are more visible."

Jan 1, 2014

By W. G. Brissenden

"ALTHOUGH I SHOULD FIRST REVIEW the state of the mining art as it is today, because of the shortness of time I will confine myself to a re-view of the more important advances in that art which have been made in the past two to three decades. Then, a look at the opportunities and the challenges which now present themselves will be more meaningfulFirst, some of the more impor-tant developments in underground mining:(1) The recognition that good ventilation, visibility and working conditions are essential preliminaries to efficient production has resulted in their incorporation as a matter of practice in modern mine planning. (2) The introduction of the car-bide bit and the re-introduction of the airleg drill, and the resulting sharp rise in productivity, were early postwar developments. (3) The recovery of the coarser fraction of mill tailings for use as mine backfill also is an important cost-reducing development of recent years -and this has led to cemented backfill, which, al-though more expensive, meets certain specific needs and has tremendous potential. (4) Great strides have been made in improving explosives' materials and explosives' accessories. Millisecond-delay electric blasting caps, which improve fragmentation and reduce the seismic effect of blasting, and the development and •application for underground use of explosives are but two among many such improvements. (5) Trackless mining methods, using quarry-type equipment in some instances and specially de-signed low-headroom trucks, loaders and carrier-mounted drills in others have been successfully applied. (6) Dual-purpose load-haul units are now in use loading and hauling from open stope drawpoints, and smaller versions of this type of unit are in use in cut-and-fill and other types of stopes."

Jan 1, 1968

A major highlight of Fiscal Year 1993 is the completion of a new research facility dedicated to the advancement of robotics research and development. This new facility brings to the U.S. Bureau of Mines one of the largest and most unique facilities of its kind in the world. Located at the Bureau's Pittsburgh Research Center, the facility consolidates under one roof, all of the resource requirements of a first class automation and robotics research program. The Mining Robotics Development Center (MRDC) is the result of a major renovation of a large under-utilized warehouse-type structure and brings together the laboratories and offices previously housed in five separate buildings scattered throughout the Pittsburgh Research Center's 238-acre site. This new facility will support the computer-assisted mining research program, a high priority, multi-million dollar program that is expected to have a high impact on the health and safety of miners and coal productivity.

Jan 1, 1993

Control of construction projects is the responsibility of the Project Leaders who have the authority to make decisions. Project Controls cost and scheduling systems provide the Leaders with timely information on which to base their decisions.The Client (Owner) will invest up to three per cent of the project cost on Project Controls. To ensure that this investment is effective, the Owner or Manager must have a clear understanding of the information required from the Project controls systems. If appointing a single Managing Contractor, the Owner or Manager must stipulate what is and what is not required from the Project Controls Systems. There are numerous computer programs available for scheduling and cost control and it is important to select systems which best serve the Owner's needs.

Jan 1, 1993

By V. A. Ettel

Current practices in electrolytic winning and refining of copper , nickel and zinc are reviewed from the point of view of their respective energy requirements. The electrical energy requirements of these processes are broken down in to the individual components, which belong to two basic categories: (a) thermodynamic energy requirements (G of the desired reaction) : (b) energy losses (anode and cathode polarizations, ohmic drops in the electrolyte and in the cell hardware, energy losses due to unwanted side reactions and electrical shorts). The individual energy components are separately examined for each electrolytic process and the potential for energy saving in these processes is discussed. It is shown that many potential energy-saving measures are uneconomical at the present time, as they increase over-all operating costs. The discussion is focused on those approaches which hold most promise for the future.

Jan 1, 1977