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By Xinchun Li, Youdi Zhang

AI is one of the computing methods, artificial intelligence performs its calculation by simulating the intelligent behavior of human beings. It is regarded as one of the most important scientific achievements in the 20th century, A1 has been developed rapidly in recent years with the development of the computer technique .The application of AI in the mineral industry has also obtained rapid progress sine AI has been used in early 1980's, such as evaluation of resource, underground mining, surface mining and mine safety etc. It has played an important role for increasing mining efficiency, improving mining management and ensuring the safety of the miner. An integrated A1 system has been developed for coalmines environment management in this paper.

Jan 1, 2002

By Jack W. Murphy, Kent J. McGrew, Rudolph H. Jacobson

Introduction Maximization of profit consistent with environmental protection is the principal goal of new applications development for any conventional or in-situ mining technique. Efficient evaluation of all the parameters that contribute to mining costs and production hinges on proper design and evaluation of testing programs and data. The program discussed herein utilizes several field and laboratory procedures to estimate ore deposit characteristics and optimize lixiviant compositions. The ore characteristics and lixiviant compositions are then used in a long path leaching test (stream tube test). The stream tube test data are analyzed by mathematical models with computer assistance to predict such well-field rate parameters as target metal production, lixiviant consumption, and restoration. When these predicted rates are combined with market values for target metals, capital expenditures, prices of lixiviant chemicals, and other economic variables such as labor costs, power rates, licensing fees, and others, an assessment of the relative feasibility of various proposed mining plans is possible. The flowsheet in Figure 1 illustrates this process.

Jan 1, 1984

By Lindsay Norman

To many who for years have scrutinized the US mineral supply picture, recent, often strident debate on present-day security of many critical mineral supplies echoes sentiments repeatedly expressed in the past decade by the minerals industry. At no time since the last world war has such a flurry of public concern been expressed for the economy's mineral sector. Where once mineral availability problems were relegated to the newspaper's business section or not reported at all, today comprehensive analyses of our international mineral posture are discussed in detail by some of the nation's most respected and widely read periodicals. In past years, disinterest was also experienced whenever the mining industry attempted to carry its message to Congress, the public, and the government's executive branch. Among minerals professionals, the past decade was a time of particular frustration clue to serious erosion ill US ability to competitively produce the vast array of raw materials vital to the economy acid national defense. Fervent calls for immediate attention were simply not answered. These professionals have understood that mining and agriculture are the primary sources of wealth, fulfilling virtually all needs and creating and sustaining jobs. Why then has it been so difficult to raise the consciousness of the American public, and even more surprisingly, of the government and national leadership? The answer to this question is perhaps endemic to how government functions, but pore important, it begs that mining professionals capitalize on the opportunity and the attention now at hand. Carefully conceived and implemented actions by both private and public sectors are needed more than ever before in the past 35 years. To this end, it is vitally important to seek out and resolve the root causes of supply problems and not dwell on superficial solutions. The following discussion attempts to establish a simple framework to view this process. It does not presume to be an exposition of cause and effect, but hopefully identifies some needed steps. Growing Awareness in the 1970s Of all events stimulating current concern, certainly the OPEC oil embargo has left the deepest impression. It was inevitable that after such a shock, man. Americans would begin asking whether the US was as vulnerable to cutoffs of minerals as it was to oil cutoffs. Then, when serious trade security questions surfaced in sonic mineral-rich nations in Africa and the Persian Gulf, the ominous term ''resource war" began to be heard. Countries such as South Africa, Zaire, Zambia, and Zimbabwe have suddenly become key areas for testing our national security resolve. As the US witnesses the influx of Marxist influence in many sub-Saharan exporting nations and the rising threat to free world access to critical materials and energy, the assurance of adequate supplies is becoming a national issue at last. The US is now learning that self-sufficiency for many vitally important mineral commodities has vanished. Of course, it did not vanish overnight; it had been leaking away for years, and the trend was noted by industry and a few in government. Within the minerals community, suspected weaknesses in America's resource posture were sought and found. As a result, the country's heavy reliance on foreign sources fur more than a score of minerals, many extremely vital to security, has been forcefully documented and the case for drastically altering the supply unbalance hits been proposed. The renewed concern for national defense is central to almost all proposals for minimizing US foreign mineral dependence. It is not surprising that many of the voices heard today on the dependency issue are active members or alumni of the militate establishment. Unfortunately, their almost total focus on the security aspects of dependency has tended to obscure important underlying issues which are not directly defense-related. Some of the proposals advanced might mitigate the deeps-dency problems, but they still fall short of curing the underlying problems that have led to a steady loss in mineral self-sufficiency. In almost all instances these problems call be traced to increasing government influence on the free market minerals economy. Some national security proponents seek to attain total self-sufficiency in minerals. Such arguments must he tempered by existing realities. It is easy to demonstrate that the US obtains substantial quantities of sonic essential minerals from potentially insecure sources abroad. That the US will continue to do so in the foreseeable future is not in doubt Uncertainty begins, however, when we try to interpret the significance of these facts. It is important to understand that mineral dependency does not irrevocably lead to vulnerability. Unlike oil, no mineral commodity combines the same degree of universal indispensibility and centralized foreign control of supplies. Moreover, although many US-required minerals are produced by fewer countries than export oil, those minerals cannot approach petroleum in economic or industrial importance. Finally, most foreign supplies come front friendly, secure nations such as Canada, 'Mexico, and Brazil. This, aid more, constitutes a vital element in US economic health as a world trading nation. The Cost of Interruption The US is currently stronger and more resilient than many expected after absorbing the oil embargo shock and subsequent price increases. Nevertheless, major worldwide

Jan 6, 1981

By R. J. Pruett, J. Yuan

Kaolin clays from five different commercial deposits in Georgia were studied to understand the variations of zeta potential and related fundamental properties. The results suggest that higher negative zeta potential is related to exchangeable or soluble calcium ions in the clays.

Jan 1, 1999

By R. K. Clifford

The formation of elemental sulfur on the surface of sphalerite in aqueous systems was investigated. Hallimond tube flotation tests showed that unoxidized sphalerite did not float well without a collector. Flotation recoveries of greater than 95 percent were obtained without the use of a collector or frother after the sphalerite had been reacted with oxygen under pressure and water at pH 2.8 at room temperature. High flotation recoveries also resulted when sphalerite was reacted in acidic solutions in the presence of platinum sponge, titanium sponge, 316 stainless steel, copper turnings, or [10-5M++]. Conditions which produced high flotation recoveries of sphalerite yielded contact angles of 37° to 40° and also produced elemental sulfur. The increase in elemental sulfur on the surface of sphalerite was detected by elemental sulfur extraction with petroleum ether, electron spectroscopy for chemical analysis (ESCA), and the electron beam microprobe. The quantity of elemental sulfur formed was insufficient to be detected by infrared or Raman spectroscopy, or by the optical microscope or by the scanning electron microscope. An electrochemical type reaction for the production of elemental sulfur in acidic solutions was proposed. The cathodic reduction of oxygen was the slow step which needed to be catalyzed. A chemical type reaction which produced H2S rather than elemental sulfur was evident in non-oxidizing conditions.

Jan 1, 1974

By M. E. Grimes

Rio Algom Mines Ltd. owns eight uranium mines and mills in the Elliot Lake district of Ontario, seven of which were producing before 1960. At present only one mine is operating meeting current contract requirements. Under present economic conditions, it is not feasible to mine ore of less than 2.0 lbs./ton U308, although there are very large reserves below this grade. We are interested in preconcentration for three possible applications: to extend ore reserves by permitting use of lower grade ore, to reduce costs on processing of present grade ore, and to reduce capital investment in expanding production to meet future production goals.

Jan 1, 1973

By H. R. Cooper

Refinements and increased sophistication in modeling and simulation, and introduction of advanced techniques in automatic control made feasible with digital processor handling of data, represent the most significant fields of advancement during the past ten years. Extensions in capability to predict performance of beneficiation and other mineral extraction techniques now provide powerful assistance to developers and and designers of minerals processing unit operations and complete plant flowsheets. Computer aided advances are categorized by work in the following fields: - Steady state modeling and simulation of processes - Dynamic modeling and simulation of processes - Optimization methodology in crushing, grinding, and flotation - Optimal process control methods - Expert systems in process control

Jan 1, 1989

By T. J. Fenner

Research conducted in South African mines has demonstrated the benefit of ground penetrating radar for the detection of geologic features and hazards. This is crucial for safety and production considerations in underground mines that are as much as 4 kilometers deep. This paper describes a new ground penetrating radar system designed specifically for high quality data acquisition, in the harsh conditions of deep underground environments, for use by operators with minimal geophysical experience. Design criteria included automated functions, intrinsic safety, light weight and minimal power requirements. Data is processed on the ground surface by geoscientists using a PC.

Jan 1, 1994

By J. W. Langhans, B. D. Blake

The U. S. Bureau of Mines has been investigating the application of thiosulfate to recover gold directly from low grade refractory carbonaceous ores for the past four years. Statistical experimental methods were used to determine the effects of various leaching parameters on both gold extraction and thiosulfate consumption. Seven variables were investigated, including thiosulfate, copper, ammonia, sulfite, and sulfate concentrations, leaching time, and leaching atmosphere. This information was used in face-centered cubic (FCC) surface response experiments to define the optimum leaching conditions for a low grade ore. Two models were generated from the data to predict gold extraction and thiosulfate consumption as a function of the leaching parameters. The models predicted a gold extraction of 67 pct and reagent consumption of 2 kg [S2032/mt ore at 0.25 M S2032-, 0.0014 M Cu2+, 0.27 M NH,OH, 0.00625 M SO;-,] and leaching for 16 h. Actual tests resulted in 62 pct gold extraction with 0.93 kg S2032- consumed/mt ore. Subsequent column leaching tests have further demonstrated the viability of applying this technology to recover gold from carbonaceous ores without first pretreating the material. Gold extractions in the column tests ranged from 69 to 78 pct with thiosulfate consumption ranging from 0.4 to 5.4 kg/mt ore. These results compare to <5 pct gold extraction using standard cyanide leaching conditions.

Jan 1, 1996

During foundry sand reclamation process development, molds formed from reclaimed chromite sand showed a rapid decline in tensile strength during thermal cycling tests. Because this characteristic could limit reuse of chromite sand in the foundry, the sand was examined in detail. Scanning electron microscopy, x-ray mapping, magnetic susceptibility, and x-ray diffraction were utilized to evaluate processed chromite sand. It was found that process variables such as binder composition, reclamation temperature, and processing method had a significant effect on the chromite sand particle surface. X-ray diffraction indicated a crystallographic change in the processed sands. Magnetic susceptibility also increased after processing. Diffusion of iron to the particle surface and increased surface roughness were identified as potential causes of the decreased tensile strength in the molds.

Jan 1, 1993

As discussed previously, total cost is the sum of the direct materials, direct labor, and production overhead costs. The assignment of direct materials and direct labor costs to individual activities is generally straightforward. The assignment of overhead often is not. Overhead costs frequently contain allocations that only approximate the demand the activity has made o; the overhead resources. The inaccuracy of the overhead calculation can create erroneous production cost information and lead to suboptimal management of the operation. This problem is particularly acute when determining the production cost of individual products in multiproduct firms. Pricing, process management, and product mix decisions are especially susceptible to errors in product costing. The problem of properly determining production cost is complicated by the fact that few if any alternative methods exist to identify the inaccuracies in overhead allocation. To avoid errors, some firms simply ignore overhead costs in their product cost calculations, particularly those resulting from marketing and distribution of the final product.

Jan 1, 1999

By Eric Forssberg, Mats Hallin

INTRODUCTION Evaluation and optimization of mineral processes has been going on since the the first plant started hundreds of years ago. A huge mass of knowledge has been collected since then. The main problem with this type of empirical knowledge of complex processes is that it is very difficult to formulate and document. The methods used for collecting the knowledge is not consistent but-varies with "he person" that does it. In the late 60&apos;s and early 70&apos;s efforts were made to use computer based techniques to evaluate process performance and to formulate process models for mineral processes. Models were developed, such as the flotation model by R. P. King (1973) which is still used to simulate flotation circuit behaviour. During the 70&apos;s. a number of mass balancing packages were developed together with process simulation packages. The industrial sector also made great efforts to develop and utilize computer based systems for process control and evaluation. The expert system that BOLIDEN created in 1974 at the Kristineberg plant was a remarkable achievement considering the hardware (CDC 3600) and the software tools (FORTRAN) available at that time. The main obstacle to successfully implement optimizing computer control of mineral processes was and still is the limited knowledge about the dynamics of complex processes. There are, however. many activities going on in this area today and it seems that the technology is very near a break through. Process evaluation is the most important tool to improve and maintain the optimal performance of a process. Today dedicated computer based techniques are used for fast and reliable screening of the processes. The stages in process evaluation consist of three basic steps: - Data acquisition, manually or by data logging. - Data refining, mass balancing and parameter calculation. - Data evaluation. The refined data can then be used for model construction/calibration and subsequently for process simulation. This paper describes two studies where the techniques mentioned above are used to evaluate and simulate

Jan 1, 1991

By Charles C. Y. Chen, Duane R. Skidmore

Batch leaching of Ohio #1, Ohio #4A and Ohio #5 coals was conducted with the thermophilic. sulfur, oxidizing microorganism: Sulfolobus acidocaldarius. Four different size fractions of each coal, with median sizes of 508, 200, 90, and 49 microns, were subjected for 10 days to leaching in a 5% coal-water slurry at 72°C and a pH of 2. Release rates and extent of sulfate and iron I1 and I11 ions from the coals during the leaching process and distribution of sulfur forms (sulfate, pyritic and organic) in the coal samples before and after treatment were determined. Data indicated that Ohio #1 coal, with an initial sulfur content of 0.6%, showed no significant changes with leaching in total sulfur content or forms of sulfur. The Ohio #4A coal, with initial total sulfur content near 5%, yielded product, for sizes below 200 microns with 90% reduction of pyritic sulfur while the extent of organic sulfur removal varied with coal particle size. Results similar to those for Ohio #4A were observed on the Ohio #5 coal, which had an initial total sulfur content of 3% and a final sulfur content near 1%. The findings were interpreted in terms of basic biological, chemical and physical mechanisms.

Jan 1, 1989

By Z. Mullard

The introduction of social media platforms has ushered in a new era of interaction and information exchange, which impact business-to-society relationships. Mining companies are closely watching these platforms, as the industry takes a cautious approach to control flows of information. This paper explores the risks, challenges and opportunities of using social media, based on a qualitative mixed methods investigation with stakeholders from the Canadian mining industry. Generational and language barriers, misunderstanding and limited motivation from regulators make implementing social media platforms challenging and risky at an organizational level. The benefits of social media include being able to mobilize communities and share information in real time. Despite the challenges, the study found that 62% of mining stakeholders are incorporating social media tools, mostly in an ad hoc manner. Flexible strategies for transparent communication and public engagement are creating new opportunities for information exchange.

Jan 1, 2011

By T. S. Golosinski

Most of the 154 t (170 st) truck fleets that were predominant in large surface mines in the 1970s and 1980s are approaching the end of their economic life. One replacement option considered by mine operators is a change to the 2 18 t (240 st) trucks. A comparison of load capacities between the 1.54 t (170 st) and the 2 18 t (240 st) trucks indicates a large productivity advantage in favor of the 218 t (240 st) trucks. This advantage, however, is often reduced by a number of site-specific factors. Therefore, a careful evaluation is required to define the actual benefit of changing to the large trucks. This article discusses some important factors that have an impact on truck size selection, based on several different studies. 218 t (240 st) trucks The 2 18 t (240 st) rear dump trucks were first introduced for surface mine service almost 10 years ago. However, it is only during the last few years that this equipment has gained acceptance in the surface mining industry. About 250 units were employed in surface mines worldwide at the beginning of 1992, and further purchase commitments are being made. Encouraged by the mining industry’s interest, all major off-highway mining truck manufacturers now offer 218 t (240 st) models (Table 1). At present, the existing 218 t (240 st) truck fleets are dominated by electric drive trucks. However, recent introduction of a 2 18 t (240 st) mechanical drive truck rounds out the development of this truck size.

Jan 1, 1992

By W. J. Miles

Many years ago, a relationship was established between dust inhalation and pneumoconiosis. Since then, various government agencies have regulated crystalline and amorphous forms of silica material in the workplace. In 1987, the International Agency for Research on Cancer (IARC) classified crystalline silica as a probable carcinogen. With this listing, crystalline silica became a regulated substance under the Hazard Communication Standard. The minerals and chemicals industries have responded in various ways. They have: • developed worker and user training programs and literature; • labeled products with appropriate warnings; • continued to implement dust reduction programs; and • developed meaningful epidemiological studies of workers. • begun development of reliable analytical methods for measuring crystalline silica at the 0.1 % threshold level; Background Silicosis historically has been the major health hazard resulting from exposure to crystalline silica. Silicosis is the scarring of the lung from excessive exposure to crystalline silica. It has been recognized as an occupational disease for more than 2000 years, since early Greek physicians noted the respiratory problems of miners, stonecutters, and quarrymen who were exposed to excessive quantities of mineral dust. During the industrial revolution, the incidence of the disease was greatly increased by the use of machinery that increased dust levels. Subsequently, the need for dust control was recognized and measures were instituted. Silicosis is characterized by progressive breathlessness on exertion and develops over the course of years. Xray images of the lungs show

Jan 1, 1990

By F. W. Brackebusch

In the paper presented by F.W. Brackebusch on the "Basics of paste backfill systems," paste fill was presented as a backfill process that offers many advantages over other alternatives such as hydraulic fill and rock fill. It was observed, however, that the mechanics of paste-fill transportation in pipelines is not fully understood and that the success of its implementation in practice depends on the precise control of the proportions of fines, aggregates and water in the mixture. The author emphasized the necessity for laboratory and full-scale testing to determine the suitability of a material to be used as paste fill. Although experimental testing is definitely an important operation in the design of a reliable paste fill, advances in the understanding of the fundamental laws that govern paste flow in pipelines are equally relevant. Ideally, the results of such efforts would provide predictive models for the rheology of the paste and the corresponding pumping-energy requirements. In an attempt to achieve this objective, an ongoing research program has been active at McGill University&apos;s Department of Mining and Metallurgical Engineering. Preliminary results showed that the underlying mechanics of paste-fill flow in pipelines may be described in terms of what is known as "plug flow," as depicted in Fig. 1. Although this flow mechanism has been known qualitatively for many years, few attempts managed to offer a comprehensive model (Gandhi, 1987; Duckworth, 1986). In our model, it is assumed that coarse aggregates present in the mixture form a porous core, which is filled with paste (fines and water) and is surrounded by an annular non-Newtonian (Bingham-plastic) lubrication layer, which enables the mixture to flow with pressure losses that are easily overcome by common positive-displacement pumps. In summary, our model predicts the thickness of the annular lubricating layer, which controls the magnitude of the pressure losses. This is done either by collecting data on the apparent viscosity of the Theologically-active fine fraction and using an analytical equation (Bouzaiene, 1994), or is done by measuring the void content of the coarse aggregates and deducing the thickness as a function of the fine- to coarse (weight or volume) fraction ratio in the mixture for a given pipe diameter and solids concentration. Our model predictions showed good agreement with data from Duckworth et al. (1986), as shown in Fig. 2.? References Bouzaiene, R., 1994, "Hydraulic transportation in mining," Ph.D. dissertation in progress, McGill University, Dept. of Mining and Metallurgical Engineering, Montreal, P0, Canada Duckworth, A., Addie, G.R., and Maffei, J.R.,1986, "Mine waste disposal by pipeline using a fine slurry carrier," Proceedings of the 11th International Conference on Slurry Transportation, Slurry Transport Association, Washington DC. Gandhi, R.L., 1987, "Effect of rheological properties of fines fraction on slurry hydraulics," Proceedings of the 12th International Conference on Slurry Technology, New Orleans, LA.

Jan 1, 1996

By G. Robert Moorehead, Peter T. Luckie, Harold L. Lovell, David J. Akers, James K. Kindig

Jigging is a process of particle stratification in which the particle re- arrangement results from an alternate expansion and compaction of a bed of particles by pulsating fluid flow. The vertical direction of fluid flow is reversed periodically. The rearrangement results in layers of particles that are arranged by increasing density from top to bottom of the bed. This response, developed from the many and continuously varying forces acting upon the particles, permits a solid-solid separation more related to particle density and less to particle size than any other "hydraulic-type" process. The stratification is usually carried out in a rectangular, open-top container called a jig, in which the mass of particles (termed a "bed") is supported on a perforated base through which the water flows in alternating directions. The coal particles, in addition to the vertically expanded and compacted bed motion, move continuously, horizontally across the supporting screen. Following the particle stratification, the particle bed is physically "cut" at a desired horizontal particle density plane to separate the desired clean coal product from the more dense refuse. The jig system includes means for continuously introducing the raw coal and for moving the water through the coal bed in a controllable manner, as well as for separating and removing the stratified particles from the system as two or more product streams. In coal preparation, this highly versatile unit operation is applied preferably to a wide size range of particles with top sizes up to 8 in. (20 cm) rather than to a closely sized fraction. In gravity ranges, the process has been applied to gold particles with a density of 19.3 and to coal particles having densities less than 1.30. Single jig washers have capacities from 5 (4.6) to greater than 700 tph (637 t/h) of feed coal. The separation results attainable by jigging have favored this unit operation as optimum for creating a clean coal product as required by steam coal specifications. Al- though the jig is used in preparing coals which are difficult to separate, its limitations to achieve both quality products and high recovery are being recognized in comparison with heavy media-based processes which make sharper separations from feeds having high "near-gravity" contents. The accu- racy of the densimetric stratification in the upper portions of the jig bed are less precise. It follows that coals with more than 10% near-gravity material

Jan 1, 1991

By M. Machina

Anew approach to the use of projectiles for rock fragmentation uses recently-developed technology to optimize projectile shape and composition to achieve the desired type of breakage. Projectiles can also be made of various materials, as determined by the requirements of downstream processes. This paper describes laboratory tests with an 21-mm (8-guage) gun, and field tests with a 60-mm cannon.

Jan 1, 2003

By Serge Payant, Michael G. Li, Lionel J. J. Catalan

Alkaline solution rinsing for decommissioning of an acid-leached residue was evaluated by column experiments, neutralization tests and solid characterization by XRD and SEM. It was found that consumption of a strong alkali during residue neutralization was much greater than that required to neutralize the soluble acidity. The excess alkalinity was consumed by solid-phase conversions unnecessary for the success of decommissioning. Alkaline rinsing did not reduce the time requirement for decommissioning when compared with plain water rinsing. Since no benefit is gained to compensate for the additional costs associated with excess alkali consumption, we conclude that strong alkaline solution rinsing is in fact inferior to simple water rinsing.

Jan 1, 1998