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This paper discusses the application of a computerised model based on genetic algorithms (GAs), called GenRel, for reliability assessment of underground mine hoisting systems. The purpose of this paper is to investigate whether GenRel can be applied to predict future failure data of a mine hoisting system based on historical records of failures. The incentive of selecting the GAs for prediction of failures is that GAs are a class of evolutionary algorithms which imitate the biological evolution procedures such as reproduction, selection, crossover and mutation. The reliability of mining equipment changes over time due to an array of factors (eg equipment age, the operating environment, number and quality of repair). These factors affect the equipment's failure patterns and have complex impacts on the equipment's reliability characteristics. The failure patterns are assumed to follow a biological evolution process, and thus GAs can be considered applicable in the modelling process.To conduct the reliability assessment, a study was carried out with historical failure data of hoists in the time period from January to December 2007. Two failure data sets of two mine hoisting systems were collected from two typical underground mines in Ontario, Canada, which are denoted as the NA mine and the SB mine. The failure data sets were prepared in the format of time between failures (TBF). Then, these data sets were entered in GenRel to generate predicted failure data sets for the period of January to March 2008. The paper discusses the statistical similarity of the actual failure data sets for the period of January to March 2008 with the predicted failure data set generated by GenRel in the same time period.

Dec 6, 2010

By R. Weideman, M. Le Roux, F. B. Waanders, Q. P. Campbell, E. Fosso-Kankeu, D. Moyakhe

"*Paper written on project work carried out in partial fulfilment of B.Eng (Chemical Engineering) degreeSynopsisSpent coffee grounds were transformed into biochar using a hydrothermal method. Some of the biochar product was pre-treated through surfactant impregnation with sodium dodecyl sulphate (SDS) to enhance its adsorption capacity. The non-treated(NT) and pre-treated(PT) biochars were characterized using FTIR spectroscopy and SEM-EDS analyses, which revealed that the products had the potential for adsorption of heavy metals from solution and confirmed the successful impregnation of biochar with SDS surfactant. The two adsorbents were then used for the removal of cadmium from solution and the adsorption behavior and capacity determined through adsorption isotherm, kinetic, and thermodynamic studies. It was found that the cadmium was adsorbed in several concentric layers on the surface of the adsorbents through a chemisorption mechanism. The PT biochar was identified as a superior adsorbent, with a capacity of qe = 10.67 mg/g compared to the NT biochar with qe = 4.82 mg/g. The adsorption of cadmium onto the PT biochar was further determined to be spontaneous and endothermic. It was therefore concluded that the PT biochar shows potential as an adsorbent and could be considered for implementation in the treatment of metal-polluted effluents. IntroductionCoal mining operations are notorious for producing large amounts of waste tailings, which are disposed of in the form of a slurry on tailings dams. This inadvertently contributes towards environmental problems (Jin, Mansour, and Thomas, 2017). Heavy metals are one of the most common pollutants that originate from solid mine waste disposal facilities, and these can leach into groundwater supplies, contaminating them and rendering the water unsuited for human consumption (Salomons, 1995). Cadmium occurs in conjunction with metalliferous ores and can cause severe damage to agricultural soils and drinking water supplies in the vicinity of mining sites (Dudka et al., 1995). It has a tendency to migrate into the surrounding vegetation, which in turn can cause harm to humans and animals when consumed (Marquez et al., 2018)."

Jul 1, 2019

By Forrest T. Moyer

Frequency rates of injuries per million man-hours of exposure were improved during 1965 slightly to moderately over those of 1964 at metal mines, nonferrous reduction and refining plants, nonmetal mills, stone quarries and mills, sand and gravel operations, and slag operations. However, at metal mills and nonmetal mines the rates of occurrence of work injuries were less favorable. The severity rates of injuries during 1965 were better than in 1964 at metal mines and mills, stone quarries and mills, and slag operations. Conversely, severity rates were worse at nonferrous reduction and refining plants, nonmetal mines and mills, and sand and gravel operations.

Jan 1, 1966

A large number of brittleness concepts have been used in very different studies in the literature. One of them is the B1brittleness concept. In this study, the objective is to criticize the B1 brittleness concept on rotary blast hole drills. The B1 brittleness concept, the ratio of uniaxial compressive strength (sc) to tensile strength (sT), are widely used as a rock brittleness concept in the literature (Inyangand Pitt, 1990; Verhoef, P.N.W. 1993; Neil, D.M. et al.1994;Becker, et al.1984; Evans and Pomeroy, 1966; Göktan, R.M.1992; Kahraman, S. 2001; Yamaguchi, U. 1970; Verhoef, P.N.W. et al.1996; Bilgin, 1982; Howarth and Rowlands,1987; Howarth, D.F. et al. 1986). So, it was used as a rock brittleness concept in this article. The value of the B1brittleness concept is equal to the tangent of ß angle in the following graph. It was seen that more meaningful relationships could be obtained with the B2 brittleness, the under ?Area?(= 1/2(scxsT) = B2) under the curve, instead of tangent ß, (=B1), of the curve.

Jan 1, 2003

By D Craw

TheSouthern Alps in the South Island of New Zealand are currently rising rapidly as a consequence of continental collision along the Pacific-Australian plate boundary. Rapid uplift has resulted in a major thermal anomaly in the shallow crust beneath the alps. Alpine topography and associated intense precipitation, coupled with the thermal anomaly are responsible for vigorous combined topographic/convective circulation of water through the shallow crust.   Uplift is greatest in a wedge-shaped region between the Alpine Fault and an associated second-order backthrust system, the Main Divide Fault Zone, approximately 20 km to the east. The Main Divide Fault Zone is segmented into NNE and NE striking faults, which are regionally sub-parallel to the Alpine Fault, but dip northwest in the opposite direction. Reverse oblique-slip on the Main Divide Fault is in an easterly direction, with a greater component of strike-slip movement on the NE trending faults. Elevated topography in the Mt Cook region is related to thrusting of a relatively homoclinal sequence of semi-schistose rocks on top of lower-grade greywacke, which controls the position of the Main Divide. Tectonically induced fluid flow resulted in only minor alteration and hydrothermal mineralisation of fault-rocks in Alpine and Main Divide Faults, and localised deposition of quartz and/or carbonate in the immediate hangingwall.   The wedge between the Alpine and Main Divide Faults is segmented by third-order structures north of the Mount Cook region. A series of right-lateral (-085/700S) and left-lateral (-150/600SW) faults, which are synthetic and antithetic to the Alpine Fault, respectively, developed as a conjugate set during uplift. Fluid-flow in the Southern Alps is controlled by these third-order fault/fracture systems. Cu-Au mineralisation, hydrothermal veins, and surface hot spring activity are localised by third-order fault/fractures and appears to be enhanced where conjugates intersect.

Jan 1, 1995

By V. Castranova

"A pneumoconiosis is best defined as the accumulation of dust in the lungs and the tissue's reaction to iu presence. Thus, silicosis is the name given to the fibrotic disease of the lungs caused by inhalation of dust containing silicon dioxide, primarily in the free crystalline form. Coal workers' pneumoconiosis (CWP), which was originally thought to be a variant of silicosis, results from inhalation of coal mine dust that usually contains relatively small amounts of free crystalline silica.HISTORYSilicosis is the older and more well known of these mineral pneumoconiosis. In contrast, CWP was not recognized as different from silicosis until the pivotal work of Collis and Gilchrist. 26 They noted that coal trimmers, i.e., special stevedores who leveled coal in the holds of ships at the Cardiff and Swansea docks in Wales, developed identical nodules on the chest radiograph to those of underground miners. The difference was that these men had never worked underground and that the coal was washed before it was loaded into ships; thus, it was unlikely that these men were exposed to silica. Gough54 examined the lungs of coal trimmers who died and found that the histologic appearance of the pulmonary lesions was distinctly different from the whorled nodules seen in silicosis. Gough,"" and subsequently Heppleston,"" then showed that the lung lesions in coal trimmers were similar to those in underground coal miners and different from those of classical silicosis. Nagelschmidt 78 analyzed the mineral content of miners' lungs that became available at autopsy. These studies caused him to propose a scheme in which the relative proportions of silica, other minerals, and/or coal deposited in the lungs determined the type of pulmonary response which develops, i.e., classical silicosis, mixed-dust disease, or CWP."

Nov 1, 1995

By Gray Mullins

The construction of drilled shafts as well as other cast in place foundation alternatives relies heavily on good practices from the contractor, engineer, and inspector in order to produce a quality foundation element. As many of the installation methods involve blind concreting processes, it is difficult to be certain of an intact concrete mass of the intended dimensions. A new integrity test has been developed that provides additional insight into the integrity of drilled shaft concrete. By measuring the temperature throughout the shaft via standard access tubes, the measured temperature profile can be compared to the normal signature associated with a shaft of the specified size. This article provides an overview of the new method development, test procedure, analysis, and results.

Jan 1, 2010

By Huang Zhiwei, Paul Skayman, Kevin Holley

In 1989 The First Brigade for Geology and Mineral Exploration of Qinghai Province discovered gold at Jinlonggou and Qinlongtan, Tanjianshan. Between 1992 and 2002 small scale mining was carried out at these sites using underground mining methods at Jinlonggou and an open pit at Qinlongtan. During 2003 and 2004 geotechnical investigations were carried out in support of a bankable feasibility study. An important objective of this investigation was to meet both internationally accepted standards and codes of practice, and also to satisfy the Chinese requirements. Extensive use of local experience was utilised. Where possible geological drilling information was incorporated into the assessment. Extensive geotechnical mapping of surface and underground exposures, and index testing to gain an appreciation of rock intact strength were used to characterise the sites. Rock mass classification (MRMR) was used to assess indicative overall slope angles and appropriate bench stack heights for the proposed pits at Jinlonggou and Qinlongtan. Measured discontinuity orientations were used in kinematic analysis to assess stability of possible pit slope geometry at a batter and overall scale to provide preliminary recommendations for the pit slope configuration. Numerical modelling was also carried out to improve the understanding of anticipated pit behaviour. Site investigation and preliminary geotechnical design details, that incorporate site specific conditions for the formation of open pits at Tanjianshan, are discussed in this paper.

Jan 1, 2006

Application of Natural Zeolite for the Removal of Diethylenetriamine (DETA) and DETA-Metal Complexes from Flotation Process Water

Sep 13, 2010

By C. C. Russelll, V. T. McLemore

The Metals Mining Sector of the Acid Drainage Technology Initiative (ADTI-MMS) addresses technical drainage-quality issues related to metal mining and related metallurgical operations, for future and active mines, as well as, for historical mines and mining districts. One of the first projects of ADTI-MMS is to develop a handbook describing the best sampling, monitoring, predicting, mitigating, and modeling of drainage from metal mines, pit lakes and related metallurgical facilities based upon current scientific and engineering practices. One of the important aspects of planning a new mine in today’s regulatory environment is the philosophy of designing a new or existing mine or expansion of operations for ultimate closure. The holistic philosophy taken in the ADTI-MMS handbook maintains that sampling and monitoring programs should be designed to take into account all aspects of the mine-life cycle. Data required for the closure of the operation are obtained throughout the mine-life cycle, from exploration through post-closure.

Jan 1, 2004

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

Mineralisation was identified at Gladstone Hill as far back as the late 1870s-early 1880s, shortly after the initial discovery of mineralisation at what is now the Martha Mine. Indeed, early recovery problems associated with the Martha mineralisation led to the preferred development of ore bodies within what is now the Union Hill Joint Venture tenement; ore bodies such as Silverton, Amaranth, and Union to name a few. Gladstone Hill forms the basis of the Union Hill Joint Venture, a 50:50 joint venture managed by Au-Ag Resources Ltd (a fully owned subsidiary of Otter Gold Mines Ltd), and Welcome Gold Mines Ltd (a fully owned subsidiary of the Normandy Group). The joint venture participants also operate the adjacent Martha Mine. Mineralisation of Gladstone Hill, as with mineralisation at the adjacent Martha Mine, has been interpreted as a low sulphidation epithermal Ag-Au system hosted within hydrothermally altered andesites of the lower Coromandel Group. Drilling in recent years has successfully identified extensive mineralisation associated with a number of vein sets throughout the tenement including the Gladstone Vein set, the Moonlight Lode and more recently along a north-easterly trend towards the historic Favona workings. A wide range of vein styles is apparent, ranging in character from thin stock works to broader lode-style banded chalcedonic to cherty quartz and have been interpreted as representing multiple phases of emplacement. At shallower levels mineralisation is often hosted by vein clasts within vent breccias. Visible gold is rare, with mineralisation generally associated with very fine-grained pyrite, arsenopyrite and minor electrum. Percentage levels of combined sphalerite-galena-(+/- chalcopyrite) have been intersected at depth however these have been gold poor to date. The potential for the Gladstone Hill area remains to be clearly defined as drilling to date has yet to close off mineralisation both along strike and down dip. If further drilling is successful, the joint venture partners believe Gladstone Hill could contribute significantly to the economic future of current operations.

Jan 1, 2000

By Jerry D. Pfarr, Gary Loving, David G. McDowall

Introduction The Open Cut is one of the best known landmarks in South Dakota's Black Hills. It is the site of the original discovery of the Homestake ledge, or lead, in 1876. Between that time and 1945, the Open Cut produced about 36 Mt (40 million st) of gold ore, the majority of which was drawn from underground operations. In 1981, a drilling program was undertaken to determine how much ore the old timers left behind. The results of this study indicated an ore body made up of broken and caved ground, and solid blocks in pillars and crowns. Reserves are estimated at about 6.8 Mt (7.5 million st) of gold ore, grading at 4 g/t (0.116 oz per st). Total tonnage of material, including waste, is estimated at more than 60 Mt (66 million st). The mining plan is a combination open pit and underground operations. The bottom 78 m (255 ft) will be mined by the underground panel-caving method. The open pit was designed as a contractor operation up to the expected milling stage or the point of sustained ore production. The pit was designed to avoid disturbance of US Highway 85 near Lead, SD. In 1983, the South Dakota Board of Minerals and Environment approved the mining and reclamation plan. Test mining began in the north of the Open Cut using open pit methods. Upon completion of the test pit, Homestake Mining's board of directors approved an expanded mine plan. They committed an additional $27.1 million to prestrip the ore body that is expected to yield 23 t (750,000 oz) of gold. Project life is estimated at 15 years. Exploration program In early 1980, 10 diamond drill holes were drilled from the surface in the vicinity of the east side of the Open Cut. The reserves delineated by that drilling were too small to justify their development. A continuation of this study attempted to quantify the tonnage remaining in the bottom of the Open Cut in the crushed remnants of old stope-and-crown pillars. This was originally thought to be minable by improved drawhole methods using highly mechanized procedures. By early 1981, however, thinking turned toward surface mining methods. The effort to quantify minable ore tonnage ultimately involved drilling 385 reverse-circulation rotary drill holes. These were drilled from August 1981 to March 1983 in several groups of holes. Each group, or drilling program, had a slightly different immediate goal or purpose. The holes were drilled to various depths using truck-mounted Drill Tech 40 drills with doublewalled 76 mm (3 in.) pipe with 134 mm (5.25 in.) three-cone rotary bits. Initially, wet drilling was employed using a cyclone collection system. Since cutting recovery was not as high as it should have been, all subsequent drilling was dry. The cuttings were collected and deposited by way of a cyclone into the sample bag. The pickup for the cuttings using the three-cone bits was about 50 mm (2 in.) above the bottom of the hole. Overall cutting recovery for the drilling program was estimated at 75%. Samples were taken on each 1.5 m (5 ft) of hole drilled. Each sample was split into three 48-g (1-2/3 assay ton) charges. The accepted value was the straight average of the three charges. Because of the known "nugget effect," assays were nearly impossible to duplicate. Therefore, to validate the regular assays, a series of screen fire assays were run. Based on this method of assays and checks, it was concluded that 10% more ounces would be produced than indicated by mine grade. Test pit The northernmost portion of the mine as planned is known as the Terraville test pit. This portion was mined ahead of the rest and separately. It provided answers to questions on slope stability, reserves correlation, mill recoveries, mining costs, and surface mining conditions in various weather and ground conditions since many boulders and much timber were expected. The mining plan for this portion of the pit was successful. More ore was mined than was expected. Mixing of Open Cut ore with underground ore in the mill feed was successful. Impact on the surrounding communities

Jan 10, 1987

By S H. Son, M K. Wang, H K. Jeong, B K. Cho, J I. Park

The utilisation of low-grade raw materials such as fine iron ore and semi-soft coking coal, and reduction of CO2 emissions are important issues in the ironmaking process. To solve these issues, a new process called PosPRA (POSCO prereduced agglomeration process) has been developing at POSCO. It focuses on the reduction of carbon composite iron ore briquette in travelling grate. In this study, the possibility of manufacturing the prereduced agglomerate (PRA) under oxidising atmosphere with travelling grate and the optimum manufacturing conditions of carbon composite iron ore briquette are investigated. The results have shown that controlling the temperature and oxygen potential in the range from 1100 to 1200°C and below 10 vol per cent respectively is very important to increase the reduction efficiency of briquette in travelling grate. High quality properties of the green briquette and PRA could be manufactured by using the briquette mixed with 20 wt per cent of coal under 0.1 mm in size under compacting pressure in the range from 3 to 7 t/cm. Adding 1 wt per cent water as a binder is proper under the condition of high compacting pressure. In a pot grate test, the compressive strength and metallisation degree of PRA are achieved over 150 kgf/p and about 55 per cent respectively, at bed temperature 1150°C and oxygen potential of 10 vol per cent when 20 wt per cent of coal is mixed in the briquette.CITATION:Wang, M K, Son, S H, Park, J I, Jeong, H K and Cho, B K, 2017. Development of prereduced agglomeration process using carbon composite iron ore briquette in travelling grate, in Proceedings Iron Ore 2017, pp 111–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Edward L. McHugh, Stanley M. Miller, Jeffrey K. Whyatt

The point estimation method can be applied to the safety factor (SF) equation for any specified rock slope failure mode (such as plane shear, step path, or wedge) to obtain reliable estimates of the mean and standard deviation of the SF probability distribution. A gamma probability density function is recommended for modeling this probability distribution, because it allows only for positive values and is flexible enough to provide symmetrical shapes and right-skewed, exponential-type shapes for the SF distribution. The mean and standard deviation define this distribution, which then can be integrated numerically from 0 to 1 to obtain the probability of sliding, PS (portion of the SF distribution where SF < 1.0). The overall probability of failure, PF, for the potential slope failure mass is the joint probability that the rock discontinuities are long enough to allow kinematic failure (PL) and that sliding occurs along the rock discontinuities (PS); that is, PF = PSPL. This method for estimating the probability of sliding is extremely efficient computationally, and thus, expedites slope stability simulation routines used by NIOSH software to stochastically describe rock slope behavior and assist the engineer in designing catch benches for large rock slopes. Enhanced bench design translates into increased operational efficiency and safer working conditions in open pit mines and quarries.

By R. M. Whyte

The Konkola Deep Mining Project (KDMP) seeks to exploit the deep level potential of the Konkola Deeps orebody, producing high grade copper concentrates for treatment at the Nkana Smelter and Refinery. As an alternative to smelting, Konkola Copper Mines (KCM) has examined a processing route involving pressure leaching of the Konkola concentrates at Nchanga, with the leach liquor being treated by solvent extraction and electrowinning to produce high purity copper cathode. The solvent extraction circuit would be operated to achieve a high ?delta? copper, thereby providing a strong acid raffinate which can be used in the existing Tailings Leach Plant (TLP) to treat Nchanga oxide copper materials. The main focus of the hydrometallurgical option is to capitalize upon the synergy that exists between the treatment of sulphide copper concentrates (acid producing) and oxide copper ores (acid consuming). The paper discusses the key features of a comprehensive piloting campaign carried out at Anglo American Research Laboratories, which involved the co-treatment of Konkola copper concentrates and Chingola refractory ore in a fully integrated pilot plant circuit.

Jan 1, 2001

By A. T. Haile

Detailed monitoring of the response of the rock mass between rockbolt reinforcement units subjected to a simulated seismic source has been successfully conducted. This work has shown the increase in amplification of the Peak Particle Velocity (PPV) with distance from a rock bolt unit, and, a minimum PPV for rockburst damage for the given site characteristics. This understanding, at this site, will allow the design of a suitable rock bolt spacing to prevent unravelling of the rock mass between the rock bolt units for a given level of seismicity. Or, alternatively, an estimation of the requirement for a suitable fabric support system, for the anticipated level of seismicity, can be made.

Jan 1, 2001

By R. A. Franks, G. F. Friel, J. C. Edwards, L. Yuan

The reversal of smoke products-of-combustion (POC) from a mine fire was determined in a mine section with the airway connectivity of an electrical Wheatstone bridge. Four diesel-fuel fire experiments with fire heat-release rates between 504 and 771 kW were conducted in the Safety Research Coal Mine (SRCM) located at the National Institute for Occupational Safety and Health’s (NIOSH) Pittsburgh Research Laboratory (PRL). Smoke reversal propagated upwind from the fire with significant leakage into the upwind diagonal airway and without causing a complete reversal of airflow in the diagonal airway. A control measure consisting of a brattice suspended half entry height from the entry roof was determined to abate the smoke rollback. Computational fluid dynamics (CFD) analysis of the smoke movement agreed with the measurements.

By R. D. Saltsman

This report is in fulfillment of Contract No. H023001.5 awarded to Bituminous Coal Research, Inc., on November 15, 1972. The scope of the work under this contract was to perform a two-phase survey for the purpose of determining the status of work in the following specific areas of industry needs under the Technology Transfer Program and to increase industry&apos;s awareness of research efforts under the Federal Coal Mine Health and Safety Act of 1969 6f (P.L. 91-173): 1. Research and development of respirable dust sampling instruments which will more accurately collect the respirable Cuss as defined by the Federal Coal Mine Health and Safety Act of 1969. 2. Development of a better means of control of respirable dust and float dust.

Jan 1, 1973

By M Fewings

This paper casts a light on the sometimes murky world that lies between base metals product æout the gateÆ, and money in the bank. Whether your base metals are leaving the mine as a refined product, or as an ore or concentrate, the generally accepted method of value determination is a London Metal Exchange price, usually measured at some point after the material has left your control. In this paper, the structure and operation, regulation and the reasons for the use of the London Metal Exchange are explored. In addition, the risks and opportunities that terminal market pricing provides to mine managers are explained, with particular reference to hedging. The paper also deals with the structure of the sales contract, including management of shipping issues, agreement of delivered quality, documentation and administrative issues. The selection of counterparties, the role of traders in the market and the growing influence of China and India as base metal consumers and competitors are also addressed.

Jan 1, 2006