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By G. Włoch, E. Rudnik

The oxide fraction of industrial zinc ash was characterized in terms of chemical and phase composition, leaching behavior in sulfuric acid solutions, and leaching thermal effect. The waste product contained about 68 percent zinc (Zn), 7 percent chlorine (Cl), 2 percent aluminum (Al) and less than 1 percent other metals, such as iron (Fe), manganese (Mn), calcium (Ca) and silicon (Si). It consisted mainly of zinc oxide contaminated with metallic zinc and zinc hydroxide chloride. The dissolution of metals from the zinc ash was determined for solid-to-liquid ratios ranging from 100 to 500 kg/m3, acid concentrations of 10 and 20 percent, and temperatures of 20 and 40 °C. The best result — 130 g/dm3 Zn(II) at 95 percent zinc recovery — was obtained at a solid-to-liquid ratio of 200 kg/m3, sulfuric acid concentration RI SHUFHQWDQGLQLWLDOWHPSHUDWXUHRI ƒ& 7KH¿QDOVROXWLRQVZHUHFRQWDPLQDWHGPDLQO\E\0Q ,, DQG)H ,,, ions, but the presence of cadmium (Cd(II)) and lead (Pb(II)) ions enabled electrowinning of zinc of about 99 percent SXULW\DWKLJKFXUUHQWHI¿FLHQF\RI WR SHUFHQW /HDFKLQJRIWKHPDWHULDOZDVDQH[RWKHUPLFSURFHVVZLWKUHDFWLRQ heat of about 520 kJ/kg

By Flavia de Paula Vitoretti

Pelletizing of iron ore fines is an important process used to produce high quality of raw materials for the subsequent reduction processes in the ironmaking industries. The process involves the production of green pellets and subsequent induration on a traveling grate furnace to promote inner partial melt and agglomeration which confer physical and metallurgical proprieties appropriated to the subsequent reduction processes. The pellets are produced with addition of charcoal to improve efficiency in the reduction processes. The lignin coal from sugarcane straw is an alternative source to replace the charcoal or coke in the self reduction of pellets. This work focused on the influence of biomass on the chemical kinetics parameters inner agglomerate pellet structure under industrial process conditions of the travelling grate furnace due hot gas flows within the pellets.

Aug 1, 2018

This appendix contains the list of equipment selected for the capitol cost estimate, with the respective quotations from their vendors/manufacturers. A vendor response report along with a separate equipment and motor list has been included in the first part of this appendix.

Jan 1, 1979

By P. Clifford

FIPR-sponsored research will playa critical role in enhancing the competitiveness of the Florida phosphate industry as ore grade declines and environmental restrictions tighten. FIPR's program seeks to improve surface mining and pipeline transportation while reducing the energy cost for pumping phosphate matrix. The development of a reliable on-line analyzer and a modern process control strategy will result in improved processing efficiency. Significant improvement in overall efficiency will also be realized as the industry adopts column flotation technology. Economic acidulation of high-Insol rock will allow the industry to adopt simplified flotation flowsheets thereby reducing operating costs. Various applications of phosphogypsum would save the industry millions of dollars in constructing and closing gypsum stacks.

Jan 1, 1998

By Calvin Konya, Anthony Konya

Presplitting is a form of blasting that when executed properly will create a smooth wall that will minimize secondary conditioning. In recent years, presplitting has become a popular technique to be used in both the mining and construction industries, however, presplitting fails on many occasions because of ‘geologic conditions’. This is typically because of improper explosive loads consisting of overloading and underloading blastholes. In this paper the authors introduce new factors such as a presplit factor which varies for different rock types, selection criteria for the spacing of presplits, and the optimization of explosive load for the technique of Precision Presplitting.

Jan 1, 2017

By Jay F. Colinet

Longwall mining in lower seam heights may necessitate the use of single-drum shearers to overcome size constraints associated with standard double-drum shearers. To avoid the operational problem of clearance in the tailgate entry with one single-drum shearer, two single-drum machines can be operated on the same face, with each shearer responsible for mining a predefined portion of the face. However, utilization of two shearers on the same face necessitates the positioning of one shearer operator and a jacksetter in the return air of the upwind shearer, thus complicating respirable dust control on the longwall. In an effort to evaluate the unique dust control problems associated with this type of mining, the U.S. Bureau of Mines conducted dust surveys on two multiple-machine longwall operations. Sampling was done to quantify major sources of respirable dust and to identify potential solutions to problem areas. Sampling results indicate that the cutting sequences utilized on multiple-machine faces may have to be designed to minimize dust exposure, as opposed to optimizing productivity or facilitating operational requirements. Also, state-of-the-art dust control techniques typically found on double-drum shearer longwalls must be employed to help minimize the exposure of all face personnel to traditional dust sources.

Jan 1, 2010

By B. Caines

Much of the mining industry in North America is in a crisis state. Host producers are operating at production levels well below capacity, some have been merged or sold, while others have been mothballed or closed permanently. For many of us still operating, the future is uncertain. Despite the many cutbacks and closures, there is still an abundant supply of minerals in the world market and there is almost no hope for any relief on price pressures on most mineral commodities in the near future. The Iron Ore Company of Canada (IOC)operates an iron ore mine, a concentrator and a pellet plant known as the Carol Project located in Labrador City, Newfoundland. This concentrator and the pellet plant have the annual capacity to produce 20 million and 10 million tons respectfully. A company owned and operated railway links this operation with the dock terminal facilities in Sept Iles, Quebec.

Jan 1, 1987

By Derek du Preez, Andrew Hall, Timothy M. Pelech

Net Present Value (NPV) derived from Discounted Cash Flow (DCF) analysis remains the dominant metric for evaluating mining projects despite its well-documented inability to capture managerial flexibility under uncertainty. DCF assumes that all risks are perfectly priced by financial markets. This is an unlikely assumption for volatile commodity prices, geological variability, or the array of mining technical and operational risks present on all mine sites. Real Options Analysis (ROA) was developed to remedy this limitation by explicitly valuing the ability of managers to defer, expand, scale, switch, or abandon investments as new information emerges, and to capture upside and mitigate downside risks. While ROA is philosophically correct and routinely shows an uplift in project value compared with DCF, its practical application at industrial scale is severely constrained, ROA faces the reality of a combinatorial explosion in complexity of decision trees, Monte Carlo simulations and other models required when multiple interdependent or sequential options exist across numerous mining zones and time periods. The AMC Hill of Value® (HoV) process adopts the same intellectual foundation as ROA, that flexibility has economic value, but operationalizes it through a far more robust and scalable architecture. It is built on parametric relationships, rapid scheduling, and multi-objective evolutionary optimisation. HoV can evaluate millions of compound, interdependent real options in a single optimisation run, delivering resilient, adaptive strategies that preserve managerial flexibility while simultaneously optimising NPV, mine life, risk exposure, and other corporate objectives. This paper demonstrates that HoV is the practical, industrial-scale embodiment of real options thinking in mining: it discovers, ranks, and translates the most valuable real options into strategic mine plans, overcoming the scalability barriers that have prevented widespread adoption of classical ROA.

Feb 22, 2026

By K. E. Robinson

Appendix A is an abridged extract of the report prepared by the Geotechnical and Structural Engineering Society of Idaho, and presents the results of their one-year study to evaluate the feasibility of disposing mill tailings by landfill construction. Appendix B describes the field and laboratory testing program completed by RDM to assess the effectiveness of a soil (slimes) liner as a means of seepage control to reduce the introduction of contaminants into the local ground water regime. Appendix C presents a summary of a thesis by Lawrence Martin on the analysis of the acid production potential of mill tailings, and the results of geotechnical testing of mill tailings completed by ROM. Appendix D describes potential landfill sites identified within the study area, the development of these sites to meet the present needs of the mining industry and the future requirements of the community is described. Appendix E summarizes the main legislation impacting on tailings disposal. Appendix F discusses the environmental and socio-economic factors that should be considered.

Jan 1, 1981

By Erik Sherer

Indonesia is poised to become a major player in the Pacific Rim thermal coal markets. Although the colonial Dutch developed numerous coal mines in the late 1800's for steamship bunkers and domestic fuel, Indonesia's coal industry has only recently begun to actively participate in the growing global marketplace. This export coal is primarily the result of the commercial development of coal mines in eastern Kalimantan by foreign contractors. From virtually no coal exports in the late 1980?s, Indonesia's coal industry has increased its exports to approximately 15 million metric tons (Mmt) in 1992. In 1992, Indonesia was the world?s sixth largest exporter of steam coal, By the year 2000, Indonesia projects that it will supply approximately 25 percent of the seaborne thermal coal requirements of the Pacific Rim countries. Although limited quantities of this coal may enter the European and U.S. markets, high qualities, low production casts, and favorable transportation rates will make Indonesian coals very competitive in the rapidly growing Pacific Rim markets. This study examines the Indonesian coal mining industry and compares it to the U.S. coal mining industry. This report is the sixth in a series of coal exporting country studies requested by the House Appropriations Committee. Previous studies examined the Colombian, Canadian, Australian, South African, Polish, and Venezuelan coal industries.

Jan 1, 1994

By D. J. Adams

Cyanide heap leaching is the predominant technology used in processing low-grade gold ores. During closure ora heap leach operation, residual cyanide must be removed from the process and waste solutions, as well as the heap. Biological cyanide oxidation is a proven, economical technology for destroying cyanide in process and waste waters and spent heaps; The use of biological cyanide degradation eliminates the need for toxic or corrosive chemical oxidizers and has- been implemented at full scale at treatment costs usually <$0.50/1,000 gal. The Applied Biosciences biological cyanide destruction (BCND?) process has been demonstrated to effectively treat cyanide, concentrations up to 350 mg/L. Treated process solutions and wastewaters also contained other contaminants such as arsenic, copper, iron, silver. selenium, mercury, nitrate and zinc, much of which was removed in the cyanide degradation process. Under optimal conditions, microorganisms can rapidly oxidize free cyanide in some process solutions from over 250 mg/L down to 0.1 mg/L in 4 to 5 hr. Cyanide is degraded to ammonia and carbon dioxide, with 50%ofthe cyanide carbon liberated as C02. In general, carbon tank based bioreactors degrade cyanide at significantly higher rates than process or wastewater pond configured treatments, which usually degrade cyanide-more rapidly than in heap treatments. Investigation of cell-free enzyme preparations as an alternative to live microbial cyanide degradation shows promise. Advantages of enzymes over live microbes for cyanide degradation include: (I) the ability to tolerate and degrade higher cyanide concentrations (> I ;000 mg/L), (2) nutrients to support live microbial cells are not required, (3) the effects of other toxic contaminants, such as metals, found in mining waters-are eliminated and (4) the potential for greatly increased kinetics.

Jan 1, 1998

By Edward L. Beutner, Robert M. Crump

Benson Mines low-grade iron ore reserve is a replacement deposit within the Grenville gneisses of the Adirondacks. The average grade of the crude ore is about 23 per cent iron. The iron minerals are principally magnetite and hematite disseminated throughout the gneisses as discrete grains about 1 mm in size. Both the ores that are beneficiated by magnetic means and the non-magnetic ores that are treated by a gravity method of concentration are found in stratigraphically different positions but are mined from one open pit, which is about 2.5 miles long and 800 feet wide and are treated separately. The gneisses are described and named according to the distinctive mineralogy of each. Recognition of the gneissic types permits the interpretation of the structure as a northward-plunging syncline overturned to the west. A large subsidiary anticline-syncline complex occurs on the east limb of the major syncline. Iron minerals in sufficient quantity to be considered ore are confined to areas where the footwall rock has been overturned to become the hanging wall.

Jan 1, 1968

By Charles Tkaczuk

In order to remain competitive the mining industry must keep up with changes in technology. Many innovative technologies from the mining perspective are commonplace in other industries. A ?Global? review of technologies will often reveal existing technologies that can be innovatively applied in the mining industry. Industries, which are rife with proven solutions include, medicine, biotechnology, security, manufacturing, telecommunications, etc. This paper addresses the communications aspect of mining where greater productivity, lower costs and the ability to quickly react to mining related events is obtained through an increase in remote monitoring and operating control. A review of the communications systems in place globally reveals technologies that, with minimal modification, can be immediately applied to the mining environment. We discuss the concept, advantages and implementation of existing communications technology from an industry that is not usually associated with the mining industry. This technology will form the basis of a solid platform on which can be built a state-of-the-art process monitoring, control, and communication system. This lays the groundwork for providing one solution to the underground mining industry?s most difficult problem, establishing a reliable, maintainable and cost-effective underground bi-directional wired/wireless data, video and analog communications system. We need look no further than our own doorsteps to find such a solution. The cable that you see coming from the simple green or brown box on the boulevard into your home contains hundreds of television broadcast channels, FM radio channels and data channels. And if you have a set-top box, you are in control of it all. The Cable Television Broadcast Distribution System suppliers of today are at the leading edge of converging all the different methods of communications onto a common carrier, coaxial cable or fibre optic cable. There is no fundamental difference between providing a reliable communications network to a city/neighbourhood/home/personal computer than there is to a mining operation/underground level/equipment or person. The principle is the same. Only the application is different. Realizing this, we can capitalize on the efforts of other industrial sectors, to solve our communications problem. Where else can you find a solution to a problem that is mature, having been developed with the input of thousands of engineers, and having hundreds of millions of dollars spent on research and development, manufacturing, distribution, global presence and engineering support?

May 1, 2003

By A. Sand

Within stamp-charged coke making a large volume of coal is compacted to one single coal cake before entering the coke oven chamber. This is done by means of several falling stampers in a stamping machine having a mold nearly of the oven?s dimensions. Producing a high quality coke also from inferior coals requires a cake density of approximately 80% of the coal density. Besides that the industrial stamp-charging process demands a minimum mechanical strength of the coal cake to move it from the stamping mold into the oven chamber without failure. Densification and the build-up of cake strength were investigated earlier in stamping tests using a micro-stamping device. The quantities derived from these tests (as e.g. cake density or porosity) represent average values for the entire cake. Statements describing the local compaction state at different heights are difficult to achieve without destructing the cake. In order to gain better insight into the densification process and the inner structure of the coal cake a computational model based on the discrete element method (DEM) has been set up using 2 and also 3-dimensional simulation software. The stamper?s position and velocity as well as the force acting on the stamper were monitored and the model?s response was compared against measurement data from laboratory stamping tests. It was possible to reproduce the force and displacement pattern of the stamper in response to the viscoelastic properties of the cake using standard DEM bonding and contact models. Furthermore, the rearrangement of particles in response to the compaction by the stamper was tracked by calculating their displacement at the point the stamper hit the coal surface. The latter can also be used as indicators of particle deformation or breakage. By defining control points at different heights the particle displacement, stress and strain rates, porosity could be studied at different heights. Keywords: coke making, coal stamping, compaction, agglomeration, DEM, simulation

Sep 1, 2012

By S Nie, I Bergqvist, F Ouchterlony

In blasting, a few or many cracks are driven from the borehole into the rock. But what causes the cracks? The most common theory of breakage consists of two stages; first the shock wave causes radial cracks to form around the hole then the gases penetrate into the cracks, and widen them and make them longer. Another theory presented by Brinkmann suggests that the back damage is primarily controlled by shock and that the gas penetration is the mechanism controlling breakout of the burden. He did his experimental work using blasthole liners. Recent research at SveBeFo has examined this matter further. In a quarry a number of benching holes have been blasted simultaneously. In some of these holes tubular Swellex bolts were inflated and decoupled charges put inside the tubes without stemming. Other holes were identically charged but without the lining. Finally some holes were also stemmed. After blasting the cracks in the remaining rock were studied. There was no difference in crack lengths between holes charged normally (no stemming) and holes where the charges were inside the bolts. On the other hand when stemming was used, the crack lengths increased for some explosives but remained the same for an emulsion explosive. In another set up blasted granite blocks were charged in the same way as above. Then we could also measure the bore hole pressure. The pressure gauge consists of a small carbon resistor inside a steel cylinder. It is called LHM (Location-fixed Hydrodynamic Measuring Cup) and is placed at the bottom of the hole. A smaller exit hole from the bottom is drilled for the cables. The paper presents the technique and the results obtained from both the quarry blasting and the blasting of the blocks.

Jan 1, 2001

By Tim Lundquist

Disa Technologies Inc. provides innovative, sustainable solutions for mineral processing and remediation through its patented High-Pressure Slurry Ablation (HPSA) technology. HPSA processes solid feed material in slurry form, propelled by high pressure pumps through opposing nozzles that generate impinging jets within a collision housing. This process induces particle-to-particle collisions in a high energy zone, creating intergranular fractures along grain boundaries. In our batch scale and continuous operating testing, we have found that controlling key processing variables such as nozzle velocity, slurry solids percentage, and the number of passes can allow for controlled size reduction and maximum mineral liberation. Since 2018, Disa Technologies has demonstrated the versatility of HPSA by testing it on diverse materials, including phosphate, copper, uranium, vanadium, zinc, rare earth elements, lithium, nickel, mineral sands, gold tailings, and more. The intent of this paper is to present an overview of our test results describing in detail impacts on size reduction, recovery, and grade with a focus on HPSA's adaptability across ore types. Looking forward, it explores the potential to process materials such as DR-grade iron, clay, PGMs, bauxite, and various tailings. Additionally, it examines planned advancements in HPSA technology, including optimized nozzle spacing, higher capacity models, improved tonnage-to-footprint ratios, enhanced maintenance features, and expanded nozzle configurations.

Jan 1, 2025

By K. Olsen

As aluminum alloy usage in automobiles grows, there are increasing demands on recycling processes and facilities to deal with mixed alloy automotive aluminum scrap. These processes and facilities strive to produce near virgin aluminum stock, which can be relatively costly and difficult. One alternative is to use physical processing methods to upgrade the scrap properties instead of chemically refining the scrap. The Impulse Atomization Process (LAP, patent pending) is a new process for making metallic and ceramic powders. It can produce fine homogeneous microstructures in scrap aluminum alloys due to high undercooling and rapid solidification. The particles have a very narrow size distribution and are in a convenient form for consolidation. This paper compares and contrasts the microstructural features of Impulse Atomized. and quenched Impulse Atomized powders,&apos; for both AL6061 and a scrap aluminum alloy composition.

Jan 1, 1995

By J. G. Pippenger

The Coteau Properties Company&apos;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 Peter L. Swanson

This investigation, which began 90 minutes after the February 3, 1995, seismic event, has benefitted from the assistance of a large number of individuals. These individuals provided information, data, analysis, brainstorming opportunities, field equipment, assistance with communication, conducted rock mechanics tests, and provided insight into mining in the southwestern Wyoming trona district. They include Rich Hodgson, Ron Hughes, Larry Refsdal. Mike Weller, John Kolesar, Joe Vendetti, and Rick Casey (Solvay Minerals), Dave Delling (Solvay consultant - former Solvay President), Karl Zipf (formerly with USBM, now with MSHA), Bob Friend, Bob Ferriter, Dave Ropchan, Jerry Davidson (MSHA Tech Support), Don Stauffenberg, Ben Hohler (Wyoming State Mine Inspector&apos;s office), Bruce Presgrave (USGS/NEIC), Chris Wood, Dan O&apos;Connell (Bureau of Reclamation), Sue Nava, Jim Pechmann (University of Utah), John Norgord and members of FMC&apos;s mine rescue team (FMC Corp.), Bill Walter (Lawrence Livermore National Laboratory), Ron Gerlick, Kevin Wood, and Mike Harmel (USBM rock mechanics lab), Jim Case (Wyoming State Geological Survey), and Solvay consultants. In addition, many individuals helped us gather information on other recent large mining-related seismic events in Germany, Russia, and Australia. and other parts of the United States. These individuals include Wolfgang Minkley (IfG Institut fur Gebirgsmechanik, Leipzig), Arnfinn Prugger (Potash Corp. of Saskatchewan), Hartmut Spetzler (University of Colorado/ University of Bayreuth), Sergei Stanchits (Ioffe Poly-technical Institute, St. Petersburg), Rocky Thompson (Cyprus-Amax) and numerous seismologists throughout the Internet.

Jan 1, 2011

By Thomas E. Browne

The Electric Power Research Institute Energy Supply Program is developing coal supply forecasts. By coal supply forecasts I mean the future relationships between coal price and production levels. A representative supply curve is shown in Figure l. It will make the rest of my presentation clearer if at this point I give you some background about EPRI and the Energy Supply Program. EPRI is funded by the nation&apos;s electric utility industry to develop new technologies for the production and conservation of electricity. Most of the research is conducted by outside contractors. We participate in joint projects with the Department of Energy and other organizations. The Energy Supply Program is one of three "economic" programs. The other two are Energy Demand and Conservation, and Systems. The Systems Program&apos;s main function is to provide the means to integrate the output of the other two Programs. The primary function of the "economic" programs is to provide information pertaining to future energy prices, availability, requirements, etc. to the EPRI personnel planning R&D programs. A secondary role that is becoming more and more important is providing information of direct use to the electric utility industry. I should note that the results of all EPRI&apos;s contract work are available to the general public. A "Coal Supply Analysis System" is being developed for EPRI by Charles River Associates. To the extent possible it will draw upon existing work, but much additional work needs to be done in the area of coal supply economics.

Jan 1, 1977