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By Lex L. Udy

External detonation generated plasmas, highly ionized zones of reacting material ejected from the surface of detonating ex-plosive charges, are shown to be the cause of channel desensitization, i.e., the self-quenching of a detonating explosive column loaded in a borehole with an air annulus between the explosive and the borehole wall. The effects of this phenomenon on several explosive compositions and types are demonstrated and discussed. Explosives tested include aluminum sensitized and explosive sensitized slurries, ANFO, liquid explosives and dynamites. Various techniques are described that can be used to reduce or eliminate the plasma effect.

Jan 1, 1978

By G. T. Lineberry, W. J. Wiehagen

A paradigm shift As market economists, mine managers are interested in "staying in business" and even "prospering." Bottom-line results are the "order of the day." Concern for bottom-line results can invoke questions such as how much was produced, at what cost, and was anyone injured? While these questions will always carry everyday emphasis at the mine, they are fundamentally lacking in that they often appear, especially to lower levels of management and to the production worker, as pre-eminent concerns. Driven by market economics, many organizations have decentralized, outsourced, downsized, restructured and formed new coalitions. Investments in new technology and a concentration on productivity have been an essential part of these changes, contributing to improvements in both safety and efficiency. A reason for (and, perhaps a result of) these improvements has been the development of a highly experienced and flexible work force. This situation presents an interesting opportunity to modify a few paradigms about work life in general, and perhaps a few paradigms about how we invest in the miner, in particular. Studying these issues now night offer some interesting opportunities for the Future, as the foundations for the next generation of mine workers are laid. With the average "experienced" U.S. miner five to fifteen years from retirement, perhaps a key determinant of future success in the world market might be how well we make the transition from today's work force to the work force of tomorrow. We can ill afford to wait a few more years to tap into the special knowledge residing within a veteran mining work Force. The Work Crew Performance Model (WCPM) is one approach to defining, capturing and transferring this expertise. The WCPM suggests a paradigm shift, moving from a focus on products (quantity) to a focus on the process (quality). It also involves a slight change in the process -- a different way to think and work. Of great importance, it entails a belief and a commitment to people within the organization; a commitment to collect simple (but interesting) data; exploration for insightful ways to plot and integrate that data; and finally the search for creative methods to reinvest that knowledge back into the organization, that is, back into the work force. As a way of thinking, the WCPM subordinates information about how much is produced daily or how many were injured over a year's time to concern and detail for how the individual's and the work crew's performance contribute toward meeting organizational goals. Drawing upon the expertise within members of that work crew to address and solve operational problems is one approach for meeting organizational goals. This everyday focus on how we work is hypothesized by the WCPM to make the difference between a good section supervisor and the average one; an exemplar continuous-miner operator and the run-of-the-mill one; a mining crew that produces consistently high quantities, but, inadvertently, degrades the production of other units. The WCPM permits objective and reliable performance data to be collected. This data then can be used to define variability within tasks of work crew members; to relate observed variability to a cost consequence; and to more meaningfully analyze performance through the integration of traditional analytical tools, such as the production simulator, CONSIM, with a recommended behavioral approach, the WCPM. Basis for engineering test Most equipment selections and purchases involve a field trial test of the system. Technology is routinely bench tested at the manufacturer's facility, government agencies and the mine site. The WCPM suggests a similar, but more practical, method for testing the performance of a work system -a test for how technology is used (by people) at the work site. It implies learning from veteran mining personnel that have gone well "beyond the book." This approach to learning and to integrating training with everyday work life can help answer questions such as: What constitutes desirable perfor¬mance as, for examples, a shuttle-car operator, a miner operator or a bulldozer operator; what characterizes exem¬plary performance within the context of the work system, the technology and the work crew; how can investments in the worker he linked to measurable results within the organiza¬tion? This paper explores these questions and makes recom¬mendations for enhancing the cost-linkages between invest¬ments in people and the mine's monthly cost sheets.

Jan 1, 1996

By Winthrop F. Watts, Robert W. Waytulonis

During the 1980's. the Mine Safety and Health Administration (MSHA) proposed new regulations for the use of diesel equipment in underground coal mines, and the National Institute for Occupational Safety and Health (NIOSH) recommended that whole diesel exhaust be regarded as "a potential occupational carcinogen", and that reductions in exposure to exhaust pollutants would reduce excess risk. During the same time, the Bureau of Mines tested new emission control technology to minimize diesel emissions. The objectives of this paper are to discuss the major issues regarding diesel exhaust emissions. especially diesel particulate matter (DPM) , and to highlight emission controls that will be available. DPM is a potential health threat because it is respirable in size and is composed of nonvolatile carbon with adsorbed or condensed compounds. These compounds include potentially mutagenic or carcinogenic hydrocarbons such as polynuclear aromatic hydrocarbons and sulfates. DPM contributes to the degradation of air quality in mines with typical mean concentrations ranging from 0.2 to 1.0 mg/m3. In addition to adequate ventilation, control of DPM can be achieved by implemention of improved work practices, regularly scheduled engine maintenance, and emission controls.

Jan 1, 1991

By Vas Choudhry

INTRODUCTION Traditionally mineral processing equipment has been procured based on (equipment) specifications prepared by the engineers. As newer materials of construction are being used for equipment manufacture and plant control systems become more sophisticated, the need for thorough and detailed specifications is greater than ever. For example, it is not uncommon to find plants looking at grinding circuits consisting of semiautogenous mills with variable speed, gearless, drives of large horsepower. Technical specifications for the mill, wrap- around motor and control system must, therefore, be carefully prepared to ensure that the respective equipment supplied by vendors meets overall grinding needs. Various engineering and design companies have expended considerable time and effort in developing the specification format. Equipment manufacturers have also given significant effort to developing data sheets aimed at collecting information regarding not only the duty of the equipment, but also the conditions under which it will be operated. As engineers moved from one company to another, the specification format became cross-fertilized and further developed. As a result, specifications on file with various engineers have improved considerably over a period of time. Equipment specifications from earlier projects are commonly used as a basis for tailoring new ones. To keep equipment specifications short, general technical considerations are often compiled as separate specifications. For example, general considerations applicable to the design, manufacture and supply of the mechanical equipment are consolidated under "Standard Requirements for Mechanical Equipment” and included along with that specified for purchase. As the economic feasibility of the project has been established during earlier studies, purchase-related activities can be initiated following completion of the specifications. Procurement itself is a major activity, however, in this chapter only those activities directly related to the purchase of equipment will be discussed. PREPARING EQUIPMENT SPECIFICTION Specification for process equipment or machinery is written in such a way as to define exactly what is required of the equipment. Generally, mechanical

Jan 1, 1986

By Isabel F. Barton, Eytan Bos Orent, Mark D. Barton

A new examination of tabular uranium (U)-vanadium (V) deposits within the La Sal district places mineralization in the context of the complex fluid flow history that has occurred in the Paradox Basin and Colorado Plateau. As the only currently producing district of this deposit type in the region, the La Sal district provides excellent opportunities to study deposit- and district-scale features that can serve as exploration guides where exposure is limited. The absence of major structures along a narrow and elongate mineral trend that runs E-W across the southern part of the Utah-Colorado border indicates a regional lithologic control. The trend was likely influenced by Jurassic drainage patterns, as indicated by paleocurrent directions shown in Fig. 1. Fluvial sandstone host rocks in the Jurassic Morrison Formation contain significant evidence of multiple superimposed fluid systems that have progressively changed local mineralogy. Apart from the presence of ore minerals, remnants of fluid systems are preserved as cements including quartz overgrowths, compositionally distinct carbonates, and sheet silicates. New geochronology methods provide constraints on the timing of initial mineralization and later remobilization. U-Pb ages of calcite associated with ore minerals provide evidence for Early Cretaceous mineralization, whereas textures and K-Ar ages show that early-formed V-minerals were replaced at the expense of V-bearing micas and clays during the Eocene. The paragenesis of minerals in U(-V) deposits of the La Sal district reflects the complexity of a sedimentary

Feb 1, 2025

By Jeffery H. Stricklin

Jim Walter Resources operates five underground coal mines with longwall faces in operation in four of the mines. Due to high air velocities (1000-1200 fpm) needed for methane control together with the friability of the coal, dust control on JWR longwalls offers unique challenges. We have tested many innovative measures to reduce respirable dust concentrations on longwalls with varying degrees of success. These measures include the "shearer clearer" system, different drum water spray configurations, sprays on the longwall belt, stageloader and crusher sprays, wetting agents in the spray water system, and homotropal ventilation. Water infusion of deactivated horizontal methane drainage holes in longwall panels is now being evaluated. A study was completed in November 1986 where water was infused into two horizontal de-gas holes. Personal gravimetric samplers were used to measure respirable dust concentrations and showed a significant reduction in the infused zone. A more in depth study will be conducted. This paper will describe the dust control measures presently used on JWR longwalls, give the results of past studies, and discuss new methods proposed to control longwall dust.

Jan 1, 1987

By [Miroslaw] M. Hajdasinski

The Payback Period (PBP) is one of the most widely applied project evaluation criteria 'in the mineral industry. As much as this criterion is liked by practitioners, it is also criticized by academicians who seriously question its validity. Inspired by this criticism, the author of this paper examines the classical definition of the PBP criterion, and formulates a new one designed for both investment and borrowing projects. It is demonstrated that the PBP, in its revised version, is free from all the shortcommings of the old one, and is fully compatible with the Net Present Value (NPV) criterion, as well as with all the other NPV compatible project evaluation criteria. Since the traditional approach to the comparison of mutually exclusive projects (MEP1s) by means of the PBP criterion has been incorrect, the paper also outlines the correct approach to this problem. Finally, owing to the fact that the PBP depends on the assumed interest rate, and using a specially developed computer program, the PBP is graphically presented, in six numerical examples, as a function of the interest rate.

Jan 1, 1989

The world's largest hydraulic excavator was recently introduced at Syncrude's North Mine at Fort McMurray, Alberta, in Canada. O&K's 826t (910-st) behemoth RH400, with a 42-m3 (55-cu yd) bucket, is capable of loading 72.5 t (80 st) in one pass. Syncrude's Alberta operation is the nation's largest single source of crude oil. It is also the world's largest producer of oil from oil sands. Syncrude produces 205,000 bbl/day, expects to increase production to 225,000 bbl/day by 1999 and to 320,000 bbl/day by 2005. That translates to 73.5 million bbl of Syncrude Sweet Blend (SSB) produced in 1996, 82 million bbl in 1999 and 114 million bbl in 2005. The North Mine is a new development that will replace the current East Mine, to be depleted of oil sand by the end of 1999. The North Mine will feature hydrotransport, a new and unique method of transporting oil sand from the pit to the process plant. Oil sand from the truck-and-shovel operation will be processed through a double-roll crusher and placed in a cyclofeeder where it mixes with hot water. The material is then screened and transported by pipeline to the extraction plant. Hydrotransport will replace conventional conveyor transport for moving raw product from the pit. Mine development will also use two 290-t (320-st) haul trucks to compliment the fleet of existing 218-t (240-st) trucks.

Jan 1, 1998

By Steve Kral

The power industry throughout the world is in the midst of a significant transition that will result in a major restructuring. Deregulation of utilities in the United States is continuing, resulting in increased competition among power providers. The traditional ways that electric power is globally bought, sold and delivered will also change. However, according to the Department of Energy's (DOE) Pat Godley, one thing is clear: "Those who provide the power during the 21 st century will be those who are willing to change - those who are willing to accept new ways of doing business and willing to employ new technologies." Godley is assistant secretary of fossil energy with DOE. Her comments came during the opening remarks at the Fourth Annual Clean Coal Technology Conference, held in Denver, CO, Sept. 5-8, 1995. The conference was sponsored by DOE and the Center of Energy and Economic Development. Under the theme "Global Opportunity," more than 300 coal and utility executives spent three days discussing the new face of the electric-power industry throughout the world and the new, mostly clean coal technologies (CCT) that will be available to power providers.

Jan 1, 1995

By C. C. White

Although many notable scientific investigations relating to roof control have been made, roof control still must be considered one of the more baffling problems confronting the miner. Each year contributions are made to our understanding and techniques in dealing with various single phases of the overall problem, however, an equation considering all the variables involved in roof control, if formulated, would indeed be hopelessly complex. Among the factors to be considered is first, gravity which is always acting but which is sometimes less of a problem than lateral forces. There are lateral forces due to expansion, resulting from the weight of overlying rock; to these must be added lateral stresses of orogenic or tectonic orgin, which may be enormous. Stresses due to plastic flow of beds, water pressure, gas pressure, expansion due to absorption of water, faults, joints, fractures, pot heads, and the like may complicate the solution. Therefore, we must base decisions on roof control, and roof bolting in particular, largely on experience, and far too often on few "knowns" and many "unknowns", The development of "in situ" roof trusses may prove of benefit because, they unlike roof bolting, promise positive calculable roof support. These trusses require installation of steel tensioned rods in the roof, which rods are arranged to produce a stress pattern similar to a bridge truss, the roof rock acting to transmit the compression forces. The simplest form of truss (see figure 1) consists merely of two steel rods anchored at the back of holes drilled at an angle of approximately 45° over the pillars, collared near the the middle of the room, the lower ends of the rods being connected together by tierods and turnbuckles. Used in this way, a 3/4" diameter rod can offer greater support than a 10" x 5-3/4" wide flange steel beam. By tightening the turnbuckle, uplist on the roof can be produced,, the downward reaction being transmitted to the pillars by the rods. This simplest form of truss has been used in rooms up to 24' in width. Trusses of four panels, that is, consisting of a truss within a truss, as shown in figure 2, have been used successfully in rooms 30' wide. (figs 2 & 3) It appears a 6 panel truss could be used in a 40, wide room.

Jan 1, 1968

By Robert M. Mann

The Ag/S specific ion electrode has been evaluated for analysis of both free and total cyanide. Metal cyanide solutions were prepared from reagent grade compounds and by stoichiometric fixture of the metal with a potassium cyanide solution. Solutions containing Cu+1, Ni+2, Fe+2, Fe+3 and Zn+2 complexes were analyzed prior to and following EDTA pre treatment. This effort provides an understanding of the effect of each metal cyanide complex on the SIE analysis of free and "total" cyanide.

Jan 1, 1981

By Richard R. Klimpel

INTRODUCTION The process of froth flotation as a means of upgrading the quality of coal by removing water and/or ash and/or pyrite has been receiving increasing attention since the 1960's by the world-wide coal industry. Historically, coal preparation practice has involved the use of primarily gravity based separation techniques, screening, and/or water washing in removing the larger fragments of inert material from coarse raw feed coal. The preparation, handling, and cleaning of raw coal finer than 500 micrometers was deliberately avoided. Most often the fine coal that was produced would be judiciously incorporated into the bulk of the larger sized cleaned coal product or simply discarded. Since the 1960's and accelerating in the 19701s, the desirability of performing some type of coal cleaning or upgrading on the finer raw coal feed materials has been increasing. There are several apparent industrial incentives for implementing fine coal ((500 urn) processing alternatives including the gradually increasing value of the normally lost fine coal product; the additional amounts of fine coal being produced due to changes in mining techniques; the need to appropriately dewater and upgrade fine coal streams in order to meet increasingly stringent environmental regulations on water quality. storage of fines, etc.; the increasing need to lower undesired sulfur and ash contents in some coal end-use applications; and the increasing development of speciality coal use processes that require inherently finer and cleaner coal particles such as in gasification, liquefaction, fuel injection, etc. Looking at the over 70 years of mineral oriented fine particle separation successes at the industrial level, the use of froth flotation in fine coal would also seem to be a natural process to utilize at the industrial level. In the world of strictly mineral processing technology and, more importantly in the world of mineral commodity economics, there are clearly a number of advantages to using froth flotation that are well documented and universally accepted. These include: the relatively low capital and space requirements required when compared to other process options available to upgrade minerals; the extreme flexibility inherent to the froth flotation process both with regard to throughput and differences in raw feed characteristics; the general availability of a wide range of equipment sizes and reliable suppliers of equipment; and the general availability of appropriate and relatively cheap chemicals that are the major driving forces behind mineral flotation. Just how has the implementation of froth flotation fared in coal upgrading over the last 20 years? It is towards answering this question that this paper will be oriented. As such, the discussion will be somewhat philosophical. The comments offered are based on the personal experiences of this author who has worked in the basic side of inventing new flotation chemistry and flotation analysis techniques with the major overriding goal of implementing this new technology successfully at the industrial level in both coal and mineral flotation throughout much of the world. This paper is not intended to be a complete reference to all published scientific work on the subject of industrial froth flotation of coal. As a brief background to what will be expanded upon in this paper, the author would like to offer the following summary comments: 1) the industrial practice of fine coal froth flotation is qualitatively similar but quantitatively different than industrial mineral froth flotation when viewed from either research considerations, operating viewpoints or economic evaluation criteria; 2) it is clearly possible to invent and/or develop new technology (such as new chemistry and/or equipment) that can do statistically better than current plant practice in well-controlled tests in either coal or mineral flotation circuits; 3) there is so much inherent variability to the raw feed coal streams and other operating parameters that even if there is a documented technical incentive to implement some new piece of technology, the people, instrumentation and control methodology required are often simply not available or not economic unless the potential payoff is quite large.

Jan 1, 1988

By Sara J. Heinlein, George Malkos, James E. Lindell, Tony Pestonatto

The 79th Street Water Tunnel Extension Project was initially designed by the City of Chicago, Department of Public Works, to increase the capacity of the City’s south side water distribution system. MWH preformed a design review, prepared the final design and provided construction management for the City of Chicago Department of Water. Construction commenced in September 1995 and was completed in October 1999. The Project connected two existing water tunnels with a new 5.8 km (19,044 ft.) long, 4.9 m (16.08 ft.) finished diameter concrete lined rock tunnel utilizing TBM, drill-blast and mechanical hoe-ramming methods. In addition, approximately 61 meters(200 feet) of concrete lined variable cross section tunnel, a new gate shaft and a temporary construction shaft were constructed. This paper describes the construction of these features and the geological conditions encountered.

Jan 1, 2003

By J. A. Herbst

Successful transitions from micro- to macro-engineering are the keys to effective technology transfer between research and development organizations and industrial end users. At the same time, it has proven to be one of the most difficult tasks that the minerals industry has had to manage. Typically, developers of fundamental information concerning how mineral processing subsystems work have been academics and government scientists. These are the individuals giving the most important input to micro-engineering models that can benefit industrial operations. Publication is the usual route for "attempting" to transfer this technology to the end users. Unfortunately, with such publications, very little direct communication occurs concerning real industry needs or the future steps required to make the particular micro-engineering model useful. In the past, the industry has relied on in-house R&D groups and plant metallurgists to "translate" publications, to provide useful macro-engineering tools for plant applications. To some extent, engineering companies have also been asked to serve this function. However, these firms have been rather ineffective in this area since their conservative nature has caused them to look rather suspiciously at new technology. This approach to technology transfer has worked, albeit clumsily, for the last several decades. This communication system is now on the verge of total collapse due to conditions of the minerals industry. Mining companies can no longer afford the significant overhead expenses of specialized technical staffs. Universities are finding it extremely difficult to interest US students in mineral engineering programs, and funding for such programs is weak. Faculty members involved in micro-engineering research today tend to focus on pure (non-application-oriented) research.

Jan 1, 1992

By Lothar Anheuser

The appearance of very large shielded softground TBM's, of 14 m (46 ft) O.D. and more, as needed for two-lane highway tunnels, calls for a thorough search of overall stability and new solutions for front support during maintenance operations in the cutting chamber. The paper deals with the development of a shield for the planned 4 th tunnel crossing under the river Elbe in Hamburg. Specific problems arise from the high water head, the shallow overburden of loose soil and the stone-bearing mixed ground. The choice of the tunneling method and the different features provided to overcome the problems are discussed.

Jan 1, 1995

By Elisa Comis, Barbara Bitetti, Julien Pepiot, Stefano Lione, Francesc Rich

The new Lyon-Turin railway project involves the construction of a 57 km twin-tube tunnel between France and Italy. Pini France (project leader) and Systra-SWS are the designers of Construction Site 8 (CO8). This part of the project includes the construction of the tunnel portal on the Villard-Clément platform, two 2.8 km long tubes of the base tunnel in the direction of Saint Martin la Porte, the cross-passages between tubes and the niches. This paper presents the general approach followed to design the temporary support for the base tunnel, cross-passages, and technical rooms. The design of the temporary support accounts for the variability of the ground and water conditions, the excavation attended behavior, the construction planning and the identified geological hazards that could be encountered along the alignment. Particular attention is paid to the intersections between the tunnels both in terms of numerical modelling and construction methods and phases. Two types of intersections are present in the project: the intersections between the cross-passages and the base tunnel and the intersections between the base tunnel and the niches. 3D models have been developed for the tunnel intersections.

Jun 23, 2024

By Martin H. Stanczyk

Under the Solid Waste Disposal Act, the Bureau of Mines initiated several accelerated in-house research programs to develop new and improved methods of proper and economic solid waste disposal. The program being conducted at the Bureau' College Park Metallurgy Research Center is concerned with eliminating the current waste of valuable materials in municipal refuse by developing low-cost methods for reclaiming and recycling the metal and mineral values contained in incinerator residues. Each year the United States must collect and dispose of in some manner or other, about 150 to 200 million tons of municipal solid wastes. The monetary output for this service ranks third among public services, exceeded only by the costs for schools and roads based on population growth projections and materials use patterns, the quantity of refuse generated by the early 1980's may approach 300 million tons annually. Currant estimates indicate that only 10 to 20 percent of the total municipal refuse generated is disposed of by incineration. If all refuse were properly incinerated the residues would contain more than 11 million tons of iron and nearly a million tons of mixed nonferrous metals including aluminum, copper, lend, zinc, and tin.

Jan 1, 1969

By Wade N. Ellett, K. Marc Le Vier, Timothy A. Fitzpatrick, Kenneth A. Brunk

As the gold mining industry matured through the 1980' s, and into the 1990's, the development of refractory gold orebodies has become more prevalent. Newmont Mining Corporation developed and commercialized flash chlorination for the treatment of carbonaceous preg robbing ores; Homestake Mining Company developed and commercialized the industry's first application of autoclaves. Barrick installed the world's largest autoclaves on whole ore treatment a few years later. Dry grinding and roasting followed at Placer Dome's Cortez, Freeport -Independence and Newmont's Carlin operations. Today, numerous papers are presented on research efforts worldwide which address treatment of refractory gold ores by bioxidation, roasting, autoclaving, alternative lixiviant treat­ment and other novel process ideas. The overall objectives are to develop economic processes for difficult refractory ores where no process exists or conventional practice is cost prohibitive. Successful research can lead to lower operating costs, increased profits, and increased ore reserves. One such research effort directed by E I DuPont de Nemours and Company, Advanced Mining Technologies, was focused on gold ores which were refractory in nature due to the cyanide soluble copper content. Approximately five years of research effort culminated in a patented process (U.S. Patent 5,411,575)1 and the formation of a new joint venture company, AuGMENT Technologies, in 1995 with Newmont Mining Corporation. Today significant progress has been made in moving the laboratory scale tests to commercialization.

Jan 1, 1997

By B. K. Mishra, R. K. Rajamani, P. Songfack

Primary grinding in SAG mills is gaining more importance with respect to the conventional crushing, rod and ball milling operations. This is due to the reduced operating costs generated by lower steel consumption. However. SAG milling is inherently susceptible to more severe risks and problems since it attempts to combine several stages of the conventional crushing and grinding into a single stage. This paper analyzes the SAG milling operation by predicting the motion of rocks and steel balls. The well-known discrete element method (DEM) is used to calculate the trajectories of individual entities, and their collision with one another. A computer code previously used for studying the motion of grinding media in ball mills is enhanced to handle the interaction between heavy spherical steel balls and light chunks of rocks, usually ellipsoidal in shape. The DEM based software called MILLSOFT can animate the charge motion for different design of liners. A case study of a 9.75-m diameter SAG mill is presented and the effects of lifter bar height and configuration on the overall dynamics of the charge are discussed. Also the effect of spacing between liners on lifting the charge is presented. This new approach has a large potential because it shows in detail the effect of each design or operating parameter on the performance of SAG mills.

Jan 1, 1998

By B. K. Parekh

The International Symposium on Comminution was organized at Camborne School of Mines, Cornwall England. Papers covered the fundamental and practical aspects of comminution in the mineral industry. Although comminution equipment design has not changed fundamentally during the last 50 years, methods of control and optimization have improved considerably. A simulation model for batch ball milling in the rotating mill was developed as a step toward continuous simulation of ball and autogenous milling. New concepts in jaw crusher technology design and the concept of a 1.6- x 2.1-m (66- x 84- in) jaw crusher with open feed throat has resulted in power savings. The use of cone crusher technology in comminution circuits with particular reference to machine design, plant flowsheet and control figuration has been reported by Boliden Allis, of Sweden. The Whiten steady state crusher model form has been used to develop a quantitative model of 2.1-m (7-ft) cone crushers. This was done by incorporating liner age (wear) and liner length as variables on the selection of particles for breakage and thus on the product size distribution. Another paper by Lira and Karetsky discussed the development of a model based on a multisegment ball mill developed by Whiten and Kavetsky. It is capable of simulating the performance of a coarse grinding ball mill of a given diameter, ball size and mill speed.

Jan 1, 1991