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Study on the Effects and Mechanics of Na2SO3 to Chalcopyrite and Galena

Sep 13, 2010

By H. Tomlinson

Fatalities from falls of roof and coal are responsible for the death of more than 1,000 miners annually in the bituminous coal mines of the United States, or practically one-half of the total fatalities in and about these mines. The men are killed by falls singly or in small groups and little or no publicity is given these accidents as they lack the spectacular features of gas and dust explosions. As a result, the public and even the miners have the impression that accidents from falls of roof and coal are just one of the unavoidable hazards of the coal-mining industry. This belief is not true. Accidents caused by falls can be avoided largely by the application of sound engineering principles, by education, and by proper leadership in the industry, just as gas and dust explosions and accidents caused by explosives have been reduced in recent years.

Jan 1, 1933

By H. Tomlinson

Fatalities from falls of roof and coal are responsible for the death Of more than 1,000 miners annually in the bituminous coal mines of the United States, or practically one-half of the total fatalities In and about these mines. The men are killed by falls singly or in small groups and little or no publicity is given these accidents as they lack the spectacular features of gas and dust explosions. As a result, the public and even the miners have the impression that accidents from falls of roof and coal are just one of the unavoidable hazards of the coal-mining industry. This belief is not true. Accidents caused by falls can be avoided largely by the application of sound engineering principles, by education, and by proper leadership in the industry, just as gas and dust explosions and accidents caused by explosives have been reduced in recent years. The necessity for studying falls of roof and coal becomes apparent by referring to the following data from a table by Adams and Chenoweth:3

Jan 1, 1933

By S. A. Allen

The Eufaula bauxite district of Barbour and Henry Counties in southeast Alabama covers an area approximately 14 miles long, 6 miles wide at the eastern extremity near the Chattahoochee River, and 10 miles wide at the western end near the east fork of the Choctawhatchee River (see figs. 1 and 2). The long axis of this polygon bears a little south of east.

Jan 1, 1949

By Brian Y. Lattimer, Kray D. Luxbacher, Jonathan L. Hodges, Manuel J. Barros-Daza

The abstract discusses the importance of predicting fire response time (the time before conditions become untenable for firefighters) in underground coal mines. It introduces a data-driven approach using artificial neural networks (ANNs) to predict response time and fire size based on measurable parameters like CO concentration, mine geometry, air velocity, and time since fire detection. The approach was tested using simulations from fire models (FDS and FSSIM), showing promising results for real-time predictions during mine fires.

Mar 6, 2022

By J. E. Johnson

Discussion of the paper of Prof. Henry M. Howe, presented in abstract by Bradley Stoughton at the Cleveland meeting, October, 1912, and printed in Bulletin No. 71, November, 1912, pp. 1181 to 1227. J. E. JOHNSON, JR., Ashland, Wis. :-This material is largely beyond the understanding of most of us practical men, but there are certain portions of that diagram that are of enormous importance. We have been conducting a, very extensive investigation of the quality of charcoal-iron and of all iron, and we have found that this eutectic point here (indicating on chart) is a sort of balance point between the good irons and the bad ones, and I have some slides to show what practical results we have found depending on this point here on the d diagram; and it would be a mistake for men who were -concerned with operation and were getting practical results, to think that these things are of no importance. They are exceedingly hard to understand, and I confess that a great deal of them is beyond me, but there is no doubt that the quality of iron depends to an enormous extent on the location of the carbon content of the iron to the right and left of this point, and the position of that point is dependent upon the silicon, and I wish to make a plea to the practical and operating members of the Institute not to disregard this material on account of its being highly scientific, because I hope to show later that there are matters of the highest practical importance that depend directly upon certain portions of this diagram. HENRY D. HIBBARD, Plainfield, N. J. :-T understand that washed metal, which, is practically pure iron and carbon, does not solidify at one instant, is cast-iron does, but passes through a mushy stage. That has been an enigma as to how and why it did so, and possibly some light might be thrown on it in this connection. BRADLEY STOUGHTON, New York, N. Y.:-If Wittorff's propositions are accepted, washed metal containing more than 4.1 per cent. of carbon would begin to solidify as liquid plus Fe4C

Dec 1, 1912

By Azi Wolfenson

El presente artículo señala la importancia de la función del ingeniero industrial en el Perú. El ingeniero industrial es aquel que identifica, describe y mide toda clase de trabajos en relación con los factores mecánicos, humanos, y de sistemas. Su preparación debe incluir laboratorios en los métodos de observación del trabajo y las actividades en el análisis de los procesos y la técnica de su medición.

May 1, 1968

By Yajie Wang

High horizontal stress and its adverse effects on longwall gate entries have been witnessed in many US coal mines for the past years. It can cause cutter roofs and leads to roof falls either in the headgate or tailgate entries depending on the relative orientation of the panel to the maximum principal horizontal stress. Underground observations have shown that if the maximum principal horizontal stress is perpendicular to the panel entries, the roof is in the worst condition and if the maximum principal horizontal stress is parallel to the entries, the entry is in the best condition. However, little has been done about the high horizontal stress effects on panel entries subject to different orientations of high horizontal stress. In order to design a longwall panel and control the roof effectively, the redistribution and concentration of high horizontal stress field must be fully understood. Using 3-D finite element analysis, this paper presents the high horizontal stress redistribution and concentration for a retreat longwall face with different orientations of high horizontal stress. Based on the results, possible roof failures for different orientations of high horizontal stress are analyzed. A panel design criterion is recommended.

Jan 1, 1996

By Jonathan Allen, Peter Radziszewski

"Stirred mill technology dates back to 1928 where the idea to use “an agitator and spherical grinding media” was presented. The year 1948 saw the successful application of DuPont’s “sand mill” for pigment grinding. Subsequent years have led to the development of different types of stirred mills spanning a number of industries that require fine and ultrafine grinding. In the context of the mining industry, smaller grain size and other mineralogical characteristics have motivated the need to grind finer. In order to address this need, the interest in stirred milling technologies has grown over the last 20 years as can be illustrated by the large body of literature published over this same period of time. The typical observation reported in the literature is that in certain circumstances stirred milling is significantly more efficient than ball milling. Despite these developments, the tumbling mills are continuing to be used in fine and ultrafine grinding applications. The main reason for this, as communicated at the Canadian Mineral Processors roundtable discussion in 2013, is that the comfort level in understanding stirred milling technologies is not at the level of that of tumbling mills. The aim of this paper is to contribute to increasing the general comfort level with stirred milling technologies by developing a better understanding of how power and energy is affected by stirred mill impellor design and mill operation. This will be accomplished by first completing an overview of the power models found in the literature followed by a general description of DEM and CFD stirred mill models as well as the insights that can be drawn from them. Finally, a generic stirred mill power model will be presented and applied to different stirred mill types in order to develop some insights into the differences between different mill types. The paper will close with a discussion on some of the challenges that these models have and how future research might contribute to overcoming them."

Jan 1, 2014

By A. N. May

"This paper describes the present approach of the Mines Branch to the problem of measuring the stress condition in the interior of rocks surrounding underground openings. An instrument, which will be referred to as a stressmeter, has been developed at the Mines Branch to measure un-directional stress changes in absolute units. There are two modes of operation of this stressmeter. It can be regarded as a fixed instrument, in which case it is installed at the end of a diamond drill hole and left in position to record any subsequent stress changes taking place. Alternatively, three of the stressmeters can be used in conjunction with a trepanning opera-tion to allow the existing stress condition to be determined. The initial laboratory work and subsequent experiences in the field with the stressmeter are described. All the field development work on the stressmeter was made possible through the co-operation of Canadian Refractories Limited, Kilmar, Quebec."

Jan 1, 1960

By G. Bartolacci, G. Couture, Levasseur. B., A. Lockhart, D. Nathan

"Pulp and froth zone characterization in a flotation circuit to improve transport of valuable minerals remains a challenge. Even though some significant breakthroughs have been made in the development of collectors in terms of selectivity, the control of gangue drainage is still the main bottleneck to achieve the production of a clean concentrate.Over the last decade, COREM’s team has been working on technologies to improve the selectivity of flotation circuits by tuning their hydrodynamic conditions using online instruments such as the bubble viewer, Jg sensor and gas hold-up. As part of its research program, COREM also developed the half-life column that establishes the relationship between the collection zone (bubble-particle attachment) and the cleaning zone (foam) of a flotation machine. In recent years, COREM has continued the development of the prototypes to make them more robust and improve the accuracy of their measurements.Recently, these hydrodynamic instruments were installed in an industrial process at Raglan Mine in order to diagnose and control the impact of hydrodynamic parameters versus the recovery and the quality of the Ni concentrate produced. Sampling campaigns of hydrodynamic parameters demonstrated that froth height could be optimized in order to increase recovery and quality of the concentrate at the same time. The specific effect of the froth height impacts both the pulp and the froth zones. Along with the impact on the drainage of the concentrate, it was observed that froth height also contributes to enhance the collection of particles in the pulp leading to an increase in metallic units.IntroductionOnce the particles of the minerals of interest are attached to the air bubbles injected in the pulp, the flotation process is driven by air dispersion parameters and froth properties. The pulp is usually responsible for the collision between air bubbles and hydrophobic particles of interest while the froth zone aims to upgrade the selectivity of the particles floated through drainage of the unwanted hydrophilic particles. Over the last four decades, flotation hydrodynamics has been extensively studied. Superficial gas velocity (Jg), gas hold-up (eg), Sauter mean bubble diameter measurements (d32) and bubble surface area flux (Sb) are among the most assessed parameters in flotation plants worldwide either to quantify the gas dispersion parameters or to optimize them (Fournier et al., 2015). McGill University has developed several sensors able to measure these parameters at industrial scale (Tavera et al., 1996; Finch et al., 1999; Chen et al. 2001)."

Jan 1, 2017

By Holger Cordes

X-ray diffraction has long been used for qualitative and quantitative mineral analysis but Rietveld data analysis is still an under utilized method for mineral exploration and processing applications. In this full-profile approach the structural parameters of each mineral phase, together with experimental parameters, are refined by least-squares methods to minimize the difference between observed and calculated diffraction patterns. The result is a standard-less, quantitative analysis of the mineral abundance in the sample that is more accurate and considerably faster compared to traditional methods. The TOPAS software package combines a user-friendly interface with a unique approach to resolve overlapping peaks. Automated analysis options are also available and significantly reduce analysis time for routine samples. Several examples on a wide range of naturally occurring rock types are shown that illustrate the capabilities and limitations of the method. The examples include several options for the quantification of amorphous constituents like volcanic glasses.

Jan 1, 2006

By Julio C. Martinez, Jeffrey L. Rice, Hayden Weschler

This paper details the extensive underpinning required to hold up the 39th street Bridge while demolishing its massive support piers and building a 30ft deep Cut/ Cover RR tunnel beneath it. The underpinning/SOE support required the construction of 16 large hand dug pits 36ft deep that were reinforced and concrete filled. In addition, an extensive steel support system was tied into the bridge super structure. All of the underpinning/tunnel construction was done while a 110ton crane sat directly atop the heavily trafficked – 66 ft. wide bridge. The tunnel excavation, concrete lining and final bridge pier support work will also be presented. All work was done within 5ft of active mainline tracks and that required tight grouting behind all lagging to eliminate any track settlement.

Jun 13, 2021

By Yuanbo Zhang

Zinc leach residues produced by hydrometallurgical zinc plants contain many valuable elements (zinc, iron, lead, gallium, indium silver, etc), while they have not been utilized effectively hitherto. In this paper, a new process of flotation-reduction roasting-magnetic separation to recover these valuable elements from zinc leach residues is developed on a basis of mineralogy investigations of them. The results show that silver concentrate with grade of 4321.6 g/t and recovery of 80.69% have been obtained, using 1750 g/t Na2S as conditioner, 750 g/t ammonium dibutyl dithiophosphate and SN-9 (assistant collector) as combined collector and 100 g/t terpenic oil as frother, if zinc leach residues with 523 g/t silver are floated at pH = 5.0. When the flotation tailings are subjected to reduction roasting at 1100? for 2 h, the volatilizations of zinc, lead and indium are over 96%. After roasted products are treated by wet-grinding and magnetic separation, the grade of gallium and gallium in the concentrates achieved respectively reaches 1805 g/t and 1536g/t, and the recovery of them is high to 94.67% and 93.20%, respectively.

Jan 1, 2006

By R. A. V. Raff

Although falls of roof, face and rib (or side) of coal mines were the third ranking cause of disabling accidents in 1966, the accidents from these falls resulted in the most serious injuries and accounted for approximately 50 percent of the total fatalities (I). Further breakdown of these statistics shows that 88 percent of the fatal accidents occurred within 100 feet of the working face and that 96 percent of the deaths were in bituminous mines, with only four percent taking place in anthracite workings. These figures demonstrated the need for improved reinforcement procedures in operational coal mines, and they provided ample justification for research in the area of accident prevention. The purpose of this project was to investigate the use of polymers and of related techniques to achieve rock bonding and reinforcement of coal mine structures, in order to obtain better or permanent ground support (e.g., drifts, entrees, coal and ore passes, galleries, tunnels and shafts) by the fill ing of fissures in the rock, thereby preventing or delaying the onset of serious rock degradation processes.

Jan 1, 1973

By R. Larry Grayson

In the October 1998 issue of the Holmes Safety Association Bulletin, NIOSH authors Mark Stephenson and Carol Merry wrote the article Hearing loss among miners and measures to protect hearing, which focused on the extensiveness of hearing loss among miners and the use of hearing protection to prevent hearing loss. While the primary importance of engineering controls in preventing hearing loss was discussed, since miners do not generally have control over their work en­vironment or assignments, the article focused on the importance of consis­tent use of hearing protection. In this article, all aspects of a compre­hensive approach to the prevention of hearing loss in miners will be covered. The discussions will do the following: ? describe application of the hierarchy of controls in preventing hear­ing loss in miners, ? give an example for each type of control measure and its impact, ? explain the major provisions, be­yond the hierarchy of controls, of the recent NIOSH document en-titled Criteria for a Recommended Standard: Occupa­tional Noise Exposure, Revised Criteria 1998 relative to a hearing loss prevention program, and ? summarize important points on control of noise exposure for every miner to remember, equipment in most facets of operations. Miners are well aware of noisy areas in or around equipment, icluding extraction machinery such as draglines, power shovels, longwall shearers, and continuous mining machines; powered haulage equipment such as load-haul-dumps, shuttle cars, large trucks, and continuous haulage units; roof bolting machines; jackleg drills and stopers; auxiliary equipment such as compressors, fans, and pumps; size reduction equipment, etc. They are not well aware of the insidious nature of pro­gressive hearing loss, which is per­manent, but they are generally aware of what levels of noise are hazardous and what measures can be taken to reduce their personal noise exposure. Behaviorally, however, there are many reasons why miners choose not to use hearing protection faithfully.

Jan 1, 1998

By C. S. Todd, R. L. McNearny, S. Dun, P. Clark, P. W. Conrad, X. Liu, J. Q. Wu, H. Rhee, W. J. Elliot

Soil erosion is strongly related to soil hydraulic properties. Understanding how surface coal mining affects these properties is therefore important in developing effective management practices to control erosion during reclamation. To determine the impact of mining activities on soil hydraulic properties, soils from undisturbed areas, areas of roughly graded mine spoil, areas with replaced topsoil before seeding, and revegetated areas at the Rosebud Mine in Eastern Montana were evaluated. Field and laboratory studies were conducted to determine the soil hydraulic properties of the four representative areas, including particle-size distribution, organic matter content and saturated hydraulic conductivity. Using this data, Water Erosion Prediction Project (WEPP) simulations and risk analyses were performed to investigate mining’s effects on changes in soil erosion potential. Significant differences were seen in the hydraulic properties of the soils in the representative areas due to the mining and reclamation practices at the mine. The WEPP simulations show that the potential for soil erosion increases as a result of mining activities disturbing the soil. The simulations also indicate that the erosion potential may return to pre-mining levels over time with effective revegetation practices.

Jan 1, 2015

"The Dumont deposit is a large (1066 Mt probable reserve) low grade (0.27% nickel), nickel sulphide project located in the Abitibi region 25km west of Amos, Quebec. Royal Nickel Corporation acquired the project in 2007 and has since taken the deposit through pre-feasibility. And updated, revised pre-feasibility was released in July 2012.The disseminated nickel sulphide and alloy mineralization is hosted within the serpentinized dunite subzone of the Dumont Sill; a differentiated, pervasively serpentinized, ultramafic sill of komatitic affinity. Pentlandite, heazlewoodite and awaruite are the dominant nickel-bearing, metallic phases and can be recovered by conventional methods (flotation, mag separation). Non-recoverable nickel is also present within the silicate matrix of the serpentinized dunite and is locked in serpentine (Fe and Mg-rich variants) and minor olivine.A detailed mineralogical program including 1097 QEMSCAN® samples and 4300 electron microprobe points were undertaken to increase the understanding of the nickel deportment in the various recoverable and non-recoverable phases in a spatial context across the deposit. Eighty-three (83) metallurgical tests performed under a standard procedure have linked the mineralogy to metallurgical performance. This has allowed the creation and modelling of geometallurgical domains on a block by block basis to understand the recovery variation and metallurgical performance throughout the deposit. Understanding the spatial variability of Ni deportment in recoverable and non-recoverable phases through mineralogy is the key to understanding metallurgical performance thus, unlocking the value of the Dumont deposit and other large tonnage low grade ultramafic nickel deposits."

Jan 1, 2013

By T. Nghipulile, G. Dzinomwa, J. Kurasha, M. Amwaama, B. Mapani, K. Maweja, T. E. Moongo

The effect of mineralogy on the grindability was investigated using three copper ores – two sulphides and one oxide. The dominant copper minerals were identified by optical microscopy and mineral chemistry derived from SEM-EDS analysis. The sample designated sulphide 1 was borniterich, sulphide 2 ore was mainly chalcopyrite, and the oxide ore was predominantly malachite and minor azurite. The gangue minerals were identified using semi-qualitative XRD analysis. Sulphide 1 contained more than 80% (w/w) of quartz compared to about 70% in the other two ores. The Bond work indices were 13.8, 21.6, and 17.3 kWh/t for sulphide 1, sulphide 2, and oxide ore respectively. This suggested that the chalcopyrite-rich ore is the hardest, while the malachite-rich ore has intermediate hardness, and the bornite-rich ore is the softest. The brittleness indices of the ores were calculated using the chemical composition of the gangue, and a good correlation between brittleness indices and Bond work indices was observed, which highlights the importance of the gangue composition in determining the fracture behaviour of the ores. There is scope for further investigation into the relationship between ore mineralogy and comminution behaviour using other breakage characterization techniques.

Mar 30, 2023

By B. Genc, P. Malepfane

This study proposes a new approach to reduce the environmental impact during surface mining by improving environmental factors through the incorporation of carbon footprint into strategic mine planning. Two key variables were analysed by contrasting and comparing the baseline and optimised models generated. These variables include net present value, which helps determine the financial feasibility of the mining models and their carbon emissions. The variables were analysed by using linear regression, Spearman’s correlation, a P-value hypothesis, and an exponential decay test. Results show that at Mine A the projected net present value was 62% higher than when running a baseline model. Furthermore, the net present value from the baseline model portrayed a high rate of decay at 0.667 versus 0.118 from the optimised model. This indicates the baseline model’s sensitivity to long-term project timelines and fluctuating markets. The optimised method presents an opportunity to manage emissions during the high operational costs phases. It is represented by a 31% improvement in carbon emissions during the periods of high operational costs, whilst maintaining a positive net present value when compared with the baseline model. It was shown that the optimised model presents a better chance of achieving financial feasibility and balancing environmental impact, thereby ensuring that Mine A can align with the environmental aspect of economic, social, and governance principles through lowering the carbon footprint resulting from its hauling operations.

Jan 30, 2026