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Apparently there is little inclination on the part of mining engineers to supplant the transmission of power by compressed air with it's formidable rival, electrical transmission. No doubt there are many advantages to be claimed for compressed air that render it parculiary well suited for the conditions which characterise underground work.

Jan 1, 1902

By R. Altindag

In rock cutting mechanics, the effects of the rock and coal brittleness on the efficiency of cutting bits are examined by many researchers. There is no universally accepted brittleness concept as a measure of cutting efficiency. The effect of the brittleness on rock cutting has not been completely explained. The aim of this study is to correlate the relationships between Specific Energy (SE) and brittleness concepts. The applicability of various brittleness measurement methods for rock cutting efficiency has been investigated. In this study, the raw data derived from previous experimental studies were used, and the relationships between SE and brittleness concepts were investigated. The two previously used brittleness concepts, which are named as B1 (the ratio of compressive strength to tensile strength) and B2 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), and a new introduced brittleness concept named B3 (the area under line in relation to compressive strength and tensile strength) were evaluated in this study. The relations among these brittleness concepts for rock cutting efficiency were established using regression analysis. There is no correlation found between the SE values and the brittleness of B1and B2values. But, the SE is strongly correlated with the brittleness of B3. It was seen that the suggested brittleness of B3concept could be used as an indicator in rock cutting efficiency analysis.

Jan 1, 2003

By Brian A. Ferguson, Raynald O. Vezina, Marielle Gaudet, Raoul R. Boissonneault

"Kiena has been committed to developing a fresh management and employee relations approach since the commencement of production in 1981. The functional organizational structure encourages joint participation and commitment on the part of all employees to common goals in safety and production. The results over the last four years have been extraordinary. Kiena won the John T. Ryan Canada Trophy for 1983 for its safety record and has experienced a steadily increasing productivity through the application of new mining equipment and technology in the hands of a well-trained and motivated team of employees.This paper serves to highlight the fact that productivity, safetyand technical innovation are closely linked to employee participationand involvement which are likely to be the key to theCanadian mining industry's survival in the years ahead.This presentation follows up on an earlier unpublished paper, given at the 84th Annual Meeting of CIM in Quebec City in April, 1982, which discussed the philosophy and the planning which took place before implementation of the management and employee relations system at Kiena. This present paper reviews and expands on material given in the earlier work. IntroductionThe mining industry, which has always been considered as rather conservative in its approach, has experienced with some regularity, cyclical periods related to metal prices. These cycles, previously foreseeable to some extent have become less coherent over recent years during which time the industry has had to face fierce international competition. The issue to productivity is without doubt the major concern of the mining industry in Canada today and it represents the greatest challenge facing us during the present decade. Developments that have been made in mining technology over the precious two decades have failed to completely produce the significant advancements in higher over-all productivity that were expected."

Jan 1, 1987

By P. S. Paul

Mine accidents/injuries are complex and generally characterized by several factors, from technical to social characteristics. In this paper, a sociotechnical model for work injury in mines was developed and tested through structural equation modelling with application to case study mines in India. In total 14 variables were considered in this study. Most of the variables are not directly quantifiable. Instruments were developed to quantify them through a questionnaire survey. Underground mineworkers were randomly selected for the survey. Responses of 300 participants were used for the analysis. The analysis was conducted in three parts. Firstly, high-low plots were constructed to explore the variations in responses to the questionnaires by the accident involved (AG) and non-involved (NAG) workers. Secondly, a t-test was conducted to see whether the responses were significantly different for the two groups or not. The chi-square results showed significant differences of responses among the two groups. Finally, how these difference scan cause accidents/injuries in mines was hypothesized and evaluated using structural equation modelling. The measurement model of the Linear Structural Relations (LISREL) program was used to identify the latent constructs of the sociotechnical model. The structural model of LISREL was used to estimate the interrelationships among the constructs. The case study results showed that there is a sequential interaction among the sociotechnical factors leading to accidents/injuries in mines. Work hazards induce more job stress in the workers while social support mitigates the same. Job stress and safety environment predict the workers? job involvement. A worker who is more job-involved exhibits better safety performance, which in turn reduces work injury. The safety environment is shown to have a direct mitigating effect on work-related injury. The findings of this study clearly revealed that job stress and safety environment are the two key factors influencing work-related injuries in mines that need to be addressed properly through effective safety programmes.

Jan 1, 2005

By Donald J. Olson

The North 27th St. ISS Extension tunnel will, under present plans, be the last constructed section of Milwaukee Metropolitan Sewerage District?s (MMSD?s) existing deep tunnel system. The 6.5 m (21 ft) finished diameter tunnel is approximately 3,260 m (10,590 ft) long and is located in NE Milwaukee County. When disputes over the pro-cesses to be used in owner-directed pre-excavation grouting in rock threatened the completion date stipulated between MMSD and the State of Wisconsin, the MMSD and J.F. Shea, the contractor, entered into a unique agreement. Shea accepted responsibility for all shaft and tunnel grouting and water control during the project in exchange for settlement of claims related to grout quantities and perceived delays. This significantly reduced risk for the MMSD and helped ensure the stipulated completion of the project.

By G. E. S. Valadao, J. D. Miller, C. L. Lin

Filtration is an important solid liquid separation technology employed widely in the mineral processing industries. The effectiveness of the filtration operation can be influenced by numerous variables, related to the particulate phase, the slurry rheology and the equipment. The classical approach for analysis is based on Darcy's law. Knowledge of the cake poremicro structure and its correlation to macroscopic cake properties is required to model the filtration operation from a fundamental point of view. Since cake formation seems to occur randomly, a 3D Monte Carlo method was used to simulate cake formation. The configuration for simulation was a space with width of 500 m, length of 500 m and height of 4000 m. Size distributions of five different industrial products whose particle size distributions follow the Rosin Rammler distribution function were used. The particle shape was assumed to be spherical. The simulated cake structures were described in terms of volume porosity (volume of pore space per unit volume of cake) and surface porosity (area of pore space per unit area of a cross section). The results indicate: 1) it is possible to simulate 3D packing, which mimics cake structure, using the Monte Carlo method,2) segregation phenomena occurs during simulated cake formation, 3) the values of calculated porosity for simulated samples B, C, D, and E were lower than those determined for corresponding industrial products Br, Cr, Dr, and Er, and 4)some structures of simulated samples seem to correlate with laboratory leaf test data obtained for different products from plant operations.

Jan 1, 1999

By D. R. Babich, E. R. Bauer

National Institute for Occupational Safety and Health (NIOSH) researchers are conducting a cross-sectional survey of equipment noise and worker noise exposures in the mining industry. Surface and underground limestone is one commodity recently surveyed. The sound levels of mining and processing equipment were recorded to identify noise sources. Full-shift worker noise exposures were completed to determine the exposure of various occupations. This paper presents the results of the noise research conducted in both underground and surface limestone mines, detailing the equipment likely to cause worker overexposures, and the occupations experiencing overexposures. Implications for worker noise exposure reduction are also reported.

Clinoptilolite as a Low-Cost Solution to Remove Heavy Metals from Water in Mining and Mineral Processing Industry

Sep 13, 2010

By Zhuo Chen, Jun Zhou, Jiemin Zhou

Samples of the reacting suspension particles were taken from the reaction shaft of a commercial flash furnace at different heights. The processes of matte and slag formation and morphology of the samples in the shaft were observed and analyzed. Variations of matte and slag composition in the shaft were investigated. By analyzing the samples taken from the settler at different locations, settler processes were studied such as slag formation, agglomeration and separation of matte-slag phases, Fe3O4 reduction, copper-in-slag reduction etc. In accordance with the characteristic of matte and slag formation the flash furnace can be divided into 6 functional regions, and a mechanism model called as “Micro bath process” is proposed for matte and slag formation in a commercial flash furnace. INTRODUCTION During flash smelting, concentrate particles scattered in the reaction shaft complete their oxidation reactions in suspension. The droplets produced fall into the settler beneath with a small amount of un-melted solid particles, agglomerate and separate into matte and slag layers which are tapped out from their tap holes separately. With respect to the extent of slagging reaction in the reaction shaft, there isn’t any commonly accepted understanding in literature (Kimura, Ojima, Mori & Ishii, 1986; Kemori & Kondo et al.,1988; Kemori, Denholm & Kurokawa, 1989; Fagerlund &Jalkanen, 2000). Some assume that the slagging reaction in the shaft can be ignored and some propose that all slag is produced in the shaft. With regards to the characteristics of the physical-chemical changes of concentrate particle in the reaction shaft, although there are some research results reported from pilot scale and commercial scale experiments (Kemori, Ojima & Kondo, 1988; Hagni, Vierrether & Sohn, 1988; Jorgensen, Taylor, Dickinson & Stevenson, 1992; Swinbourne, Simak & Yazawa, 2002; Kivinen & Tuominen, 2005), they are generally limited themselves to theoretical analysis and calculations. No studies are published concerned with the processes of matte and slag generation in the shaft, quantitative analysis of the processes, variations of matte and slag composition and morphologies of the melts along the axis of the shaft, etc.

Jan 1, 2019

By B. Sivarama Sarma, Biswabikash Rout

"Seepage control has to be achieved with plastic concrete cut-off diaphragm walls in dam structures. Materials selected for construction of cut-off walls must be durable, impermeable and have stiffness comparable to the surrounding soil.Plastic concrete provides a feasible and economical solution for construction of durable and impermeable cut off walls for dam structures. Plastic concrete wall should not be understood as a concrete wall with similar mechanical properties of concrete used in buildings, piles and spillways sections. Though it consists of the same materials as those of conventional concrete it has the major differences in end product due to predominant addition of bentonite slurry in the mix with very high water cement ratio. This makes the hardened concrete with very low compressive strength less than 5MPa and high failure deformations after the peak load.This technical paper examines a case study, the typical specifications on demand for construction and the issues corresponding to misunderstanding of the material as a structural grade concrete material. Conclusions were drawn based on a few project site quality data and trial mix experimental data. The anomalies in specifications on demand for construction of curtain wall in a dam structure were removed with modifications.INTRODUCTIONDiaphragm walls which are constructed in trenches made of plastic concrete basically serve the function of seepage control under confined measures. They should have the ability to sustain and undergo large plastic strains as compared to conventional concrete. The three basic mechanical properties of plastic concrete cut-off walls are to have least permeability, minimum strength to retain its shape and ability to undergo large deformations under confined loading conditions. The constituents of plastic concrete are cement, bentonite, coarse and fine aggregates, chemical additives to improve flow of concrete and sometimes to retard the setting time and water."

Jan 1, 2017

By Arash Khosravifar

The seismic design of extended pile shafts for the combined effects of dynamic shaking and liquefaction-induced lateral spreading is investigated using nonlinear dynamic finite element analyses (NDA). Results of NDA parameter studies are used to illustrate how inertia and lateral spreading loads combine during shaking. The NDA results are used to evaluate equivalent static analysis (ESA) methods. Implications for design practice are discussed.

Jan 1, 2010

By S J. Brace

About 180 000 tons of explosives are used annually underground in South Africa. Most is loaded into holes less than 50mm in diameter. 75% is consumed in the gold and platinum mines where holes are between 25 and 4omm in diameter and no more than 3.0m in length. The small amount of explosives per hole with extreme conditions of heat, humidity and seismic activity, make the choice of explosive on safety and technical grounds very important to the success of a blasting operation. Taken together with the fact that many underground precious metal operations are now marginal then the choice of an explosive, when its price is also considered, becomes critical to the very viability of some mines.

Jan 1, 1994

By B C. Sarkar, D Ray, V Sarkar, P K. Sinha, R K. Singh, A Kumar

Estimation of iron ore grade distribution has been attempted using geostatistics and artificial neural network (ANN) based models for a banded iron formation (BIF) type iron ore deposit of East India. Geologically, it is a supergene iron ore formation through an enrichment process of parent material (BIFs) by gradual leaching of impurities, namely SiO2 and Al2O3. As the degree of leaching differs spatially, distribution of Fe varies depending on local controls of ore formation. While geostatistical methods work on models based on spatial correlations of mineralisation parameters, ANN models a non-linear distribution and is widely used as a global approximator. Spatial distribution modelling of Fe values has been carried out employing ordinary kriging (OK) and sequential Gaussian simulation (SGS). Non-linear modelling has been performed using hybrid neural networks (HNN) that provided an alternative option for grade estimation. Classical statistical modelling revealed a negatively skewed 3-parameter lognormal Fe population having a mean of 60.49 per cent with a skewness of -0.08 and a kurtosis of 2.60. Semi-variography and geostatistical estimation employing OK procedure led to block-by-block kriged estimates with associated kriging variance, which provided an overall mean kriged estimate and kriging variance of Fe as 60.29 per cent and 7.76 (per cent)2 respectively. SGS procedure revealed a mean of 60.71 per cent and a standard deviation of 5.89 per cent with minimum and maximum values as 45.12 per cent and 68.70 per cent respectively in respect of Fe. HNN model provided values of mean squared error (MSE) and correlation coefficient (R2) as 12.33 and 0.61 respectively, thereby exhibiting the robustness of the model to sustain maximum heterogeneity within the target domain. A comparison of Fe grade estimates obtained by kriging, simulation and HNN models more or less maintain similar distribution patterns that are close to the sample data. It is thus opined to carry out the grade prediction exercise employing all these three modelling approaches to obtain alternative scenarios for improved mine planning and design exercises. The techniques provide a foundation for cogent grade modelling leading to improved iron ore reserve estimation procedures.CITATION:Sarkar, B C, Singh, R K, Ray, D, Kumar, A, Sinha, P K and Sarkar, V, 2017. Iron ore grade modelling using geostatistics and artificial neural networks, in Proceedings Iron Ore 2017, pp 431–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Electro-Flotation Research on Fine Cassiterite

Sep 13, 2010

By L. K. Bandyopadhyay

The expert system component of Knowledge Base System supports the analysis and interpretation phases of ventilation design with an algorithmic program used for the solution of alternate design. The paper describes the ?ES-VENT? knowledge based system developed at Central Mining Research Institute, Dhanbad, India for an on-line diagnosing of the ventilation problems using the ?IITMRULE? expert system development tool. In the ?IITMRULE? expert system tool, it has been decided to use a backward chaining reasoning process to reach the goal state i.e. the final conclusion. ES-VENT system is made of three modules: On-line Data, Diagnostics and KBS. Each module is being a collection of several programs. The paper mainly deals with the parameters affecting the ventilation of underground mines such as air-velocity, air pressure, temperature, dust, and humidity and gas contents. The graphical presentation of these parameters on the computer and the interactive part of the developed program is expected to help a ventilation officer to determine the changes in a ventilation circuit necessary to bring the mine ventilation to the desired value. Once such changes are physically effected, the display will indicate if the changes have brought the desired effect or not on ventilation. Keywords: Ventilation network, on-line data, expert system, intelligent system, knowledge base, inference engine.

Jan 1, 2002

By Christophe Thiébaut

Keywords: Pyrochemistry, Salts Treatment, Distillation The pyrochemical purification of metal generates spent salts. When this metal is an actinide such as plutonium, the slags cannot be discarded and are thus disposed in nuclear facility. In order to handle with these slags, the decision has been taken to reduce stored quantities. The development of a pyrochemical treatment is in progress in the CEA Valduc centre. The feed salt, typically composed of various Pu and Am species contained into monovalent or divalent chloride matrix, is first oxidized to convert the actinides into oxides. Then the chlorides are separated from the actinide oxides by vacuum distillation. Temperatures higher than 750°C for monochloride salts mixture NaCl/KCl and higher than 1100°C for divalent CaCl2 base salts, are required to produce an industrial flow of vaporization. Inactive qualification of the process for NaCl/KCl base salt has been carried out with lanthanide surrogates. Then, a pilot equipment, called distillator has been designed and built for production-scale distillation of NaCl/KCl and CaCl2 oxidized plutonium salts. Industrial flows of vaporization have been obtained with this pilot equipment : about 4 g/cm²/h for NaCl/KCl at 800?900°C and 1 Pa, and more than 1,5 g/cm²/h for CaCl2 base salts between 1000?1200°C at 0.1 Pa. The last step, now in progress, is the integration of the distillator into a glove box.

Jan 1, 2005

By J. J. Sammarco

Illumination is essential for mine safety because miners depend most heavily on visual cues to detect hazards associated with slips/trips/falls and powered haulage. The National Institute for Occupational Safety and Health (NIOSH) is conducting mine illumination research to improve miner safety by enhancing a miner?s ability to see mine hazards. Thus far, 16 papers have been published covering diverse topics such as cap lamps, machine-mounted lighting, glare, lighting maintenance, and light-emitting diode (LED) technology issues. NIOSH has also developed an LED cap lamp, LED area lighting, and a Visual Warning System (VWS). This paper provides an overview of the improvements from NIOSH-developed lighting that include: 94% faster trip hazard detection with the NIOSH LED cap lamp; 79% faster peripheral motion detection to detect pinning/striking hazards; no increase in glare; 71% faster machine movement hazard detection with the VWS. Current research is described concerning an LED cap lamp for metal/nonmetal miners, illumination for refuge alternative deployment and inspection, and whether lighting could be used to improve miner escape and rescue in smoke. Lastly, future possibilities of using lighting to improve miner safety are described.

Feb 27, 2013

By Siegmund Babendererde, Jan O. Babendererde

Extruded Concrete Lining combines technological and financial advantages. The tunnel lining is reliably embedded in the surrounding ground as the fluid concrete is extruded at constant pressure directly behind the TBM supporting the exposed surface. Ground deformation from the TBM passage can be compensated and the ground will be pre-stressed by the extrusion process. Developments in concrete technology permit high speed tunneling by use of a slip formwork attached to the TBM. Realised projects in Milano (Italy), Lyon (France), Frankfurt (Germany) and Akima (Japan) will be demonstrated.

Jan 1, 2001

By Mark S. Stagg, David E. Siskind

The mining industry occasionally blasts near pressurized transmission pipelines and has requested guidance of safe vibration levels and setback distances. the Bureau of Mines and the Indiana Department of Natural Resources cooperated with AMAX Coal Company on a study of coal mine overburden blasting. Five buried and pressurized 250-ft pipeline sections were specifically installed on the Minnehaha Mine highwall near Sullivan, IN for testing to failure. Four welded steel pipes ranging from 6- to 20- in diameter and one 8- PVC water supply pipe were monitored for vibration, strain, and internal pressure for a period of 6 months while production blasting advanced up to the pipeline field. In contrast to previous studies of small-scale blasting representing construction activities, these tests involved overburden blasts of up to 2100 lb per delay in 12-l/4-in diameter holes.

Jan 1, 1996

By G. A. Kosick, C. A. Harris

"Metallurgy at the Polaris Mine is approaching an impasse, with lead and zinc concentrate grades and recoveries approaching their theoretical maximums. In an effort to increase productivity, plant throughput and operating material costs became a major focus of milling personnel.one method of increasing plant throughput was to minimize flotation circuit upsets by; standardizing operating strategy, decreasing control action response time of operators, increasing training of operators, and providing a more available decision support system for operators.To achieve these goals, Polaris personnel decided to utilize expert system technology to develop a real-time process controller for the flotation circuit which would be capable of justifying its actions to operating personnel.This paper describes the procedures followed in constructing the first process controller in the mineral industry which is based on the principles of Artificial Intelligence.IntroductionThe Polaris Concentrator was constructed in 1980 on a barge in Trois Rivieres, Quebec and towed to its present location on Little Cornwallis Island, North West Territories, about 1450 kilometers from the North Pole. The plant presently treats about 2,800 MTPD of new feed with average feed grades of 3% Pb, 13% Zn and 5% Fe. Current production averages 36,000 tonnes of lead concentrate and 220,000 tonnes of zinc concentrate annually.In an effort to increase the efficiency of the concentrator, the decision was made to implement an innovative control system on the flotation circuit. This system would embody and utilize heuristics ""rules-of-thumb"" gained from operators to make on-line process decisions. It would also justify these decisions on a demand basis."

Jan 1, 1988