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By S. Y. B. Subbarao, K. Ravindranath

Lead and Zinc concentrates are being recovered at Rajpura- Dariba (Distt. Rajsamand, Rajasthan, India) from a complex multi metal sulphide deposit since 1984 by selective flotation employing a large number of reagents. The cost of concentrates' production has been high. Due to the increased availability of concentrates world over and to be competitive, it is necessary to reduce cost of production. An effort has been made by the R.D. Department of Hindustan Zinc Limited to bring down the cost by resorting to production of Bulk Pb + Zn concentrate with enough Ag to make it attractive to the smelters. This paper gives an account of open cycle testing and locked cycle testing in the Dowa Continous Mini Flotation unit. The metallurgical data generated in the mini flotation unit indicate the possibility of obtaining smelter-acceptable bulk concentrates containing Pb+Zn 45%, Ag 400 ppm and graphite carbon about 3%. An in-plant trial in the 3000 TPD concentrator indicated that there would be savings through dispensing with and reduction in some reagents, lower power requirement, etc. Also, a substantial increase in revenue is expected due to higher recoveries by resorting to bulk concentrate production as against individual concentrates.

Jan 1, 1995

By A. T. Yu

Once exploration is complete, "winning" of the ore can be viewed as fundamentally a bulk handling proposition. Whether it is to strip, break, size, extract, load, haul, or even process, the success of each of these phases will depend upon how effectively one can utilize-the methods and tools that are available in bulk handling. Since as much as 30 to 60% of the total delivered price of raw materials can be attributed to handling and shipping (ref. 1), this expenditure may spell the success or failure of an entire mining venture. In fact, it has become increasingly evident that handling and shipping are so intimately associated with mining that only when they are duly considered throughout the mine-to -smelter master plan as an integral part of a total system can an optimum operation be expected and the most economical ton of ore obtained, this total systems approach should not only take in handling and haulage in and out of the mine, but also storage and transfer at the terminals (ref. 2,3,t), including ship and barge loading and unloading which are likewise a major consideration (ref. 5). Much has been developed during the past century in bulk handling, particularly in its expanding use in the mining industry. In view of the major role bulk handling has played and will continue to play in mining, in commemorating AIME's centennial, this paper will attempt to outline the state-of-the-art at this three-quarter point of the 20th century - one that is marked by its industrial revolution and rapidly accelerating technological advances. Bulk handling systems Although many developments in bulk handling are worth noting. The most significant during the past three-quarters of a century are: the total systems approach to solving problems, automation, the increase in speed and capacity.

Jan 1, 1971

By Charles H. Ricker

Simulation models have been widely used to analyze the operations and characteristics of a variety of systems. Such models mimmick a projected reality by analyzing the interaction of the events, transactions, and facilities which combine to make up the system. The models are structured as a computer representation of the system components and their logical, precedence and timing relationships. The operation of the system is then simulated over some finite time interval to gather analytical and staistical data. This paper presents a method whereby bulk handling systems, either actual or proposed, may be analyzed by means of simulation models to project the enconomic consequences which may be expected from the system over some future time interval. An example is given to illustrate the construction of bulk handling simulation models, the derivation of performance data, and the analysis of the information with an eye to effective decision making.

Jan 1, 1974

By R. Todd Swinderman

"Higher production demands across all bulk handling segments require increased efficiency at the lowest cost of operation, in the safest and most effective manner possible. As conveyor systems become wider, faster and longer, more energy output and more controlled throughput will be needed. Add an increasingly stringent regulatory environment and cost-conscious plant managers must closely review which new equipment and design options align with their long-term goals for the best return on investment (ROI).There are primarily two separate market segments using conveyor belts. One is in process industries such as food, chemicals, paper and powders. Handled in relatively low volumes, the bulk materials that enter these processes are generally of a consistent size and quality. The other market includes mining, coal handling and cement, where the bulk material’s quality and size vary, and the volumes are typically much greater. While both segments face similar issues with safety and environmental control, the properties of the materials handled and the volumes transferred suggest different approaches, with one thing in common: increased belt speeds requiring modern equipment upgrades.Safety at higher belt speedsWith companies recognizing that safety does indeed pay, safety is likely to become a new source of cost reduction. The percentage of mines and processing facilities with a robust safety culture are likely to increase over the next 30 years to the point where it is the norm, not the exception. In most cases, with only a marginal adjustment to the belt speed, operators quickly discover unanticipated problems in existing equipment and workplace safety. These problems are commonly indicated by the larger volume of spillage, increased dust emissions, belt misalignment and more frequent equipment wear or failures."

Jan 7, 2017

By R. Todd Swinderman

"Higher production demands across all bulk handling segments require increased efficiency at the lowest cost of operation, in the safest and most effective manner possible. As conveyor systems become wider, faster and longer, more energy output and more controlled throughput will be needed. Add an increasingly stringent regulatory environment and cost-conscious plant managers must closely review which new equipment and design options align with their long-term goals for the best return on investment (ROI).There are primarily two separate market segments using conveyor belts. One is in process industries such as food, chemicals, paper and powders. Handled in relatively low volumes, the bulk materials that enter these processes are generally of a consistent size and quality. The other market includes mining, coal handling and cement, where the bulk material’s quality and size vary, and the volumes are typically much greater. While both segments face similar issues with safety and environmental control, the properties of the materials handled and the volumes transferred suggest different approaches, with one thing in common: increased belt speeds requiring modern equipment upgrades.Safety at higher belt speedsWith companies recognizing that safety does indeed pay, safety is likely to become a new source of cost reduction. The percentage of mines and processing facilities with a robust safety culture are likely to increase over the next 30 years to the point where it is the norm, not the exception. In most cases, with only a marginal adjustment to the belt speed, operators quickly discover unanticipated problems in existing equipment and workplace safety. These problems are commonly indicated by the larger volume of spillage, increased dust emissions, belt misalignment and more frequent equipment wear or failures."

Jan 11, 2018

By R. W. Ballmer

Bingham Canyon lies in the heart of the Oquirrh Mountains, 25 miles southwest of Salt Lake City, Utah. In it is located the world's largest open-pit copper mine, owned and operated by the Utah Copper Division of Kennecott Copper Corporation. From the beginning of open pit mining operations in 1906 until 1963, the pit haulage, or materials transportation, was primarily by rail. In 1963, phase-in of a truck haulage system in the upper two-thirds of the pit was begun. The details of that conversion, its associated problems and the resulting pit operation have been covered in an earlier paper.1 The purpose of this paper is to discuss various factors for consideration in transportation system selection, and to discuss some of the alternatives considered prior to making the change from rail haulage to truck haulage for a portion of Bingham Canyon.

Jan 1, 1968

By Solomon J. Salat

During the major expansion of the Inspiration smelter, which took place in 1973, the bulk material handling system underwent a matching expansion in order to move the required materials. Inspiration is the first smelter worldwide to employ electric smelting in conjunction with the use of Hoboken converters (1), (2). The installation includes a 51 -MVA electric furnace, five 4.25m (14-foot) diameter Hoboken converters, rotary dryer, bedding plant, acid plant, heat recovery steam plant, and gas and dust handling system. See Figure 1, Plot Plan. As of today, the 51-MVA electric furnace is the world's largest in the smelting of copper. Engineering design for the installation was per- formed by Treadwell Corporation of New York. The task of designing the conveyor system was complex because the system had to be installed while the smelter was operating and with minimum plant shutdowns, and it had to serve both the existing and the new smelter. Existing conveyors were redesigned where necessary and incorporated into the new conveyor system. See Figure 2, Flow Sheet. The system encompasses the handling of such diverse materials as wet and dry copper concentrates, cement copper, silica flux, cold dope, and concentrate and flue dust.

Jan 1, 1979

By Rainer Kahrger

During the last decade, advances were made in solvent extraction/electrowinning (SX/EW) technologies. Combined with heap leaching, these technologies made it viable to exploit large, low-grade oxide copper deposits. The El Abra Mine is a good example for such a deposit. The deposit is situated in northern Chile at an elevation of about 4,000 m (14,000ft), 70 km (45 miles) north of Calama. Codelco sold 51% of the El Abra to Cyprus Minerals in June 1994, with Codelco retaining the balance. In 1993, Cyprus and the engineer on the project began discussions withinternational companies regarding the materials-handling system requiredfor the project. These early discussions were considered critical for this fast-track project.

Jan 1, 1996

By M. P. Evans, Rainer Kahrger

During the last decade or so great advances were made in the solvent extraction, electro winning technologies. They, combined with heap leaching, made it viable to exploit large, relatively low grade oxide copper deposits. The El Abra mine is a good example for such a deposit. Situated in Northern Chile at an elevation of about 4000m (14000 feet), 70 krn north of Calama, the El Abra deposit has been known for many years. In the early 1990's Codelco decided to sell a major holding in the deposit to international mining companies. After lengthy negotiations Cyprus Minerals finalized in June 1994 the purchase of 51% of the deposit with Codelco retaining the balance. lance. Already in 1993 Cyprus and the engineer on the project, began discussions with international materials handling companies with regards to the materials handling system required for the project. These early discussions were considered critical for this fast track project. Immediately after the notice to proceed with the project, several companies were invited to submit competitive conceptual proposals for that portion of the material handling system which was to transport crushed and treated ore from the plant to the leach pad and build the leaching heaps at a rate of up to 150 000 tons per day. A supplier was selected. Additional studies were made for the conveyor system from the mine to the fine crushing plant. Due to the extremely rugged terrain and high altitude at the mine, a decision was made to locate the plant and the leaching operations 15 km east of the mine at an elevation of 3400m. In July 1994 the supplier started the conceptual engineering with a design team at the engineer's San Francisco office. The undertaking was unique in the sense that the supplier's engineering team was integrated into the project for the duration of the conceptual engineering. The open and continuous communication greatly contributed to the success of the design work.

Jan 1, 1996

By Allan R. Ide

It is a great pleasure for me to speak-before such a prestigious group as the American Institute of Mining, Metallurgical and Petroleum Engineers. The substance of my talk today is the handling of coal and petroleum coke: their characteristics and environmental problems, and how we were able to correct the problems, prescribe the cure and enjoy the benefits. When coke first became a by-product derived from the oil refineries everyone would have been very happy if someone had offered to take this pro- duct off their hands. Unfortunately, there was no market at that time, and no one seemed interested. Soon thereafter, it became a sellable product and began to be shipped to many countries in the world. This was when all of the pollution problems began. I will be talking briefly about some of these problems and showing a short film on this subject afterwards.

Jan 1, 1984

By Stanley W. Ivosevic

Introduction Increasing investor and industrial demand for gold is not being matched by new mine output from traditional sources. This forces the exploitation of alternative natural and industrial resources to supplement traditional sources. A traditional natural resource is either high- to medium-grade ore, of gold or silver with coproduct gold. Or, they are medium- to low-grade base metal ores having byproduct gold. Traditional ores are also frequently extracted at relatively great expense by selective underground mining. Alternative natural resources include low-grade, near surface ores and the products of mining-dumps - and of onsite processing - tailings. Traditional industrial resources are newly mined gold or that obtained from plant sweepings. Their alternative analogues include gold in old scrap and chemical sludges and precipitates, notably those incidental to the electronic industry. These alternative gold resources have several attractions. They are untapped and abundantly available. Having been overlooked by prior metals suppliers, title to many alternative resources is easily acquired. Or, the value of such a resource may go unnoticed until its gold is rendered exploitable by an advance in extractive technology or an other approach. This article addresses the effect of large tonnage, low-grade lode ores on gold supply. Exploiting these ores is rendered commercial by their amenability to bulk mining by modern large-scale mining and metallurgical operations requiring little selectivity. Placer gravels, perhaps the earliest type of gold ore mined, also are bulk minable. But these fall outside the definition of being lode deposits. Most lode bulk mining is from surface open-pit mines. Some, however, is from underground by such large-scale mining techniques as room and pillar, vertical crater retreat, and end slicing. The low-grade gold ore being discussed averages 2.8 g/t (0.082 oz per st). Output How greatly do bulk minable, low-grade resources effect supply? 1982 was a somewhat healthy year for gold mining and exploration in North America in spite of the general depression in the mining industry (Table 1). The wildly fluctuating price of gold bullion had stabilized at an annual aver¬age of $12.08/g ($376 per oz) - (Handy and Harmon base price). Half of the 1.3 kt (43 million oz) of 1982 world gold mined were from South Africa's high-cost, medium-grade, selective underground mines. Of the remaining half, 20%, or about 130 t (4.2 million oz), was mined in North America. This includes Canada and the US - the third and fifth largest gold producers in the world. Of that North American production, more than 62.2 t (2 million oz) of gold, or about 50%, came from bulk mining of gold ores with or without co-product silver. Most of this was in the US, where bulk minable gold-silver lode ore produced nearly 31 t (1 million oz). This amounted to 60% of the nearly 46.6 t (1.5 million oz) produced in the US during 1982. An additional nearly 7.7 t (250,000 oz) of gold were produced as the byproduct of bulk mining of cop¬per ore, for a total of 34 t (1.1 million oz) of gold, or 75% of US gold production by bulk mining. To further illustrate this, US placer, mine dump, and related operations produced an insignificant 4% of US gold output at the time. Exploitation of bulk minable gold deposits is becoming increasingly important worldwide. Most new Australian gold mining announcements are of bulk minable developments. This trend will increase in North American mining as more large tonnage, low-grade operations come onstream in Canada, where much current production is from underground. It will increase with the general climb in Mexican gold mining. And it will grow with expansion of the 12 t/a (400,000 oz per year), gold production of the Dominican Republic. Production Metal price and operating costs make these large tonnage, low-

Jan 11, 1984

By Carl E. Nelson

Shallow epithermal stockworks hosted by maar eruption craters contain over ninety percent of the bulk mineable gold identified to date in the Circum-Caribbean region. Pueblo Viejo (Dominican Republic) and Santa Rosa (Panama) contain combined gold reserves of over 600 tonnes. Bulk mineable gold deposits are also being discovered in and around veins that were formerly mined underground. Bellavista, El Recio and San Martin (Costa Rica) contain combined announced gold reserves of over 50 tonnes. Representative rock suites collected at 8 bulk mineable gold deposits include 291 samples of veins and vein stockworks, hydrothermal eruption breccias, sinter, variably altered host, unaltered host, nearby intrusive rocks and basement. Analyses completed to date show that Circum-Caribbean epithermal ores are enriched in arsenic, mercury and antimony as well as gold and silver. Exploration efforts in the region naturally focus on districts with past production. However, an order of magnitude more bulk mineable gold has been discovered in shallow epithermal stockworks outside of the old bonanza vein camps. Exploration guides include basal island arc volcanic sequences, hydrothermal and hydrovolcanic (maar) eruption breccias, thinly-bedded carbonaceous maar sediments, and hot spring-related silicification and argillic alteration.

Jan 1, 1990

By A. T. Yu

Bulk sampling is define' as the ?process of extracting a small fraction of material from a large bulk ...sufficiently representative ...for the intended purpose.? (ref. 1). Today's pressing need for simple, effective and reliable sampling systems is intensified by the growing demand for quality control as a means to cope with inflation, competition and rapidly increasing consumption of raw materials. Much has been written on bulk sampling (ref. 2 thru 9). It involves a wide range of subjects cutting across the domains of physics, chemistry, geology, mining, materials handling and processing, as well as probability and statistics. Since the problem itself is complex, any in-depth treatment cannot avoid a somewhat lengthy coverage. Of all of the related topics. Arbitrary, haphazard studies, on the other hand, can leave out important details and obscure or confuse the issue.

Jan 1, 1970

By H. F. Broicher

Introduction In April 1998, AIS Sommer GmbH of Germany delivered the first laser-induced fluorescence (LIF) analyzer to the mining industry. LKAB's Kiruna iron ore mine in Sweden shared the costs and the risk of building the prototype. This marks the beginning of LIF analysis as a technique for quality control in mining and mineral processing. Photoluminescence analysis is well established. In most laboratories, fluorescence spectrometers are standard equipment for quality or pollution control. LIF is being used in several applications, including combustion studies and particle image velocimetry. However, it has mostly been used in laboratory environments. The availability of rugged lasers for industrial use brings this powerful tool to the forefront of production, even in the rough conditions found in mining and minerals processing. Laser-induced fluorescence Basics. Fluorescence of naturally occurring minerals has fascinated man since scientific investigation of this phenomenon commenced about 200 years ago. However, importance in industrial application and peripheral activities. Hand sorting of ore under ultraviolet (UV) lamps is seen as an archaic method. Long gone are the days when geologists set out at night with UV hand lamps to find valuable ore deposits, especially those of tungsten. Today, fluorescent minerals are considered collectors' items and museum exhibits. In the late 1960s (Hemphill, 1968) and during the 1970s, attempts to use lasers for excitation of fluorescence in minerals led to the development of an airborne fluorosensor (Seigel and Robbins, 1980). However, this prospecting technology did not gain industry acceptance and vanished from the market. During the past seven years, ongoing research of the LIF of minerals resulted in new findings that give good reason to revive the interest in fluorescence and its use in the mineral industries (Broicher and Zydek, 1995; Broicher, 1998). Fluorescence is defined as the short-lived form of photoluminescence, in which matter emits visible radiation during and after irradiation with light – the fluorescence generally being of a longer wavelength than the irradiation. Fluorescence of matter is described by: • the absorption spectrum, • the emission spectrum, • the decay curve and • the quantum efficiency. The absorption spectrum shows the fluorescence intensity in a fixed spectral band as a function of the excitation wavelength, while the emission spectrum shows the fluorescence intensity at varying emission wave- lengths for a fixed excitation wavelength (Fig. 1). The decay curves describe the exponential decrease of the fluorescence intensity with time. The quantum efficiency is the ratio of irradiating energy to emitted energy. Re- cent research has found that: the quantum efficiency of minerals can be measured and evaluated,

Jan 1, 2000

By William W. Magnus

The Eastern Magnesia Talc Company has always had the problem of adequate storage at its various mines and mills of not only crude ore and finished product but also material in process. An opportunity arose a couple of years ago with the decision to build a new mill at West Windsor, Vermont, (Figure 1) to come as close to providing adequate space for ore and the ground talc in the new plant as money and judgement would allow. Since our engineering staff did not have the time to design and engineer the new facility, an architectural firm with complete engineering staff was retained. Our original thought was to contract all phases of the construction and installation, however, and I think this is a most important point for any small firm such as ours, we found that with good supervision we, as the contractor, could do the job faster and at a lower cost than the construction firms that bid on the work. For some 50 odd years Italian talc has had a virtual monopoly in the body powder area of the cosmetic industry. Due to the purity, superior lubricity and whiteness, naturally occurring in the talc from Italy, no talc in the Western Hemisphere could capture any but a very small part of the market. When the Italian supply was cut off during World War II, the United States' largest consumer of this talc decided that it was time to develop a domestic source of a satisfactory replacement.

Jan 1, 1965

By D. Shuck

Incorporation of a 2,727 mtpd, $5.7 million flotation circuit into the Mclaughlin flowsheet was completed in November 1991. This capital addition reduced overall operating costs and improved the gold recovery of the low grade refractory reserves over that expected for direct cyanidation. In addition, flotation provided a means to generate a sulfide concentrate which is utilized to supplement feed to the pressure oxidation circuit.

Jan 1, 1994

By C. H. Perbix

[On Pier D in the Port of Long Beach, California, the Port of Long Beach has built a new bulk cement distribution terminal. The facility is operated by Pacific Coast Cement Corporation, who designed the complex and leased it from the Port of Long Beach on a 40-year lease. At one bulk cement is unloaded from vessels carrying from 12,000 to 30,000 t. The unloading is performed with pig speed mechanical unloading equipment and delivered into a concrete silo complex with, a capacity of 50,000 t. From the silos, bulls cement is loaded into trucks for delivery. The facility was completed in September 1981.]

Jan 1, 1983

By W. K. Hitchcock

Anecdotal evidence suggests that re-entering a sealed heating poses a significant hazard, whereby the original heating is rejuvenated at an accelerated rate forcing withdrawal and re-sealing of the area. Bulk-scale laboratory experiments using a two-metre column confirm these mine site observations. A high volatile bituminous coal from New South Wales, Australia was allowed to develop a significant hot spot before being inerted with nitrogen and allowed to cool. Air was then allowed back into the coal after the nitrogen was turned off and a hot spot developed almost immediately at the same location as the original hot spot before it quickly migrated towards the air source within a day. Two more re-entries were simulated. Each successive re-entry developed a broader hot spot and took longer to reach thermal runaway. These results clearly show the behaviour that can be expected when trying to recover a section of an underground coal mine that has been sealed due to a spontaneous combustion event.

Jan 1, 2009

By Greg J. Hasenfus, Allison M. Haines, Joshua M. Silvis

The floodable volume of longwall gob can be of great importance in developing accurate coal mine operation plans, particularly for mine water management and environmental control strategies. Given the inaccessibility and difficulty in direct measurement of gob characteristics following gob recompression, hydrologic, geomechanical, and spatial data and principles were used to solve for the porosity and height of the residual gob using a mathematical model framework and bulking-based techniques. Based on this approach, gob porosity of Appalachian longwalls appears to be tighter than previously reported, ranging between 4.99 and 14.31%. Residual gob height, as normalized with respect to mine extraction height, ranges between 1.90 and 2.45. A novel, bedding-based bulking approach is ampliative with respect to existing roof caving and bulking fundamentals, as it has greater explanatory value compared with the traditional, lithologic-based bulking application. The efficacy of using the residual gob characteristics determined by the mathematical model and bedding-based bulking is examined using a causal comparative method, whereby time series prediction of historical groundwater rebound is compared with observed mine pool elevation data. Prediction accuracy is significantly improved using a prototype model to calculate void volume of longwall gob, specifically, the dependence of porosity of the gob material upon the longwall width to overburden depth ratio for movement basins of subcritical and critical panel widths. The potential implication of these findings toward hydrologic, geomechanical, and ventilation studies of longwall gob could be significant.

Aug 13, 2021

By John Frostiak, Don Welch, David Landriault

The use of paste technology for underground cemented backfill is widely accepted in the mining industry today as a potentially cost effective alternative to cemented rock and hydraulic slurry fill. While paste backfill is not the appropriate backfilling method for all mines, there are presently 23 operating tailings paste backfill plants throughout the world. This new technology has gained increasing acceptance as a backfill method over the last decade and its use is now expanding into the surface disposal of tailings using the stacked, thickened tailings disposal concept. Over the next 18 months there will be ten new paste plants commissioned in the world. Five of these ten plants will be used exclusively for surface tailings disposal or a combination of surface disposal and underground backfill production. The thickened tailings disposal concept, developed by Dr. Eli Robinsky in the early 1970's, has been in use for decades at several mine sites throughout the world (Kidd Creek Mine site in Northern Ontario), but always utilizing non segregating high density tailings slurry central discharge, stacked tailings placement. With the use of a higher solids content paste, the typical 2-degree beach angle can be increased to ten degrees or more with no runoff water and minimal shrinkage crack development through desiccation. This paper presents the design of the first mine to implement true surface paste disposal, Barrick Gold Corp's Bulyanhulu Mine in Tanzania. The paste system will be commissioned in the first quarter of 2001 allowing performance data to be collected to define the full potential of paste technology for surface tailings disposal.

Jan 1, 2001