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By C. Yi, D. Johansson, C. San Miguel, M. Wimmer

Sublevel caving (SLC) is a mass mining method based upon the utilization of gravity flow of blasted ore and caved waste rock. Production blasting has significant impact on the efficiency and productivity of SLC output, affecting material fragmentation, flow and recovery. Misfires could occur during blasting in SLC, which results in the loss of explosives and poor fragmentation. Usually, the blastholes are top-initiated with redundant lower primers set at + 25 ms as a precaution. If the top primers fail, the lower primers may initiate the explosive, which will induce out-of-sequence delays that can influence fragmentation and gravity flow. This work investigated the impact of misfires and out-ofsequence delays on fragmentation and gravity flow through numerical simulations using a coupled finite element and discrete element method. Different scenarios of misfires and out-of-sequence delays were studied, and the fragment size distribution was obtained to evaluate the blasting performance. The material flow behaviour was investigated to assess the gravity flow process. The results indicated that misfires significantly affect the fragmentation and the gravity flow process while the effects of out-of-sequence delays are not so significant for the investigated cases

Jan 1, 2024

By R. M. Geisenheyner

We are in the midst of a transportation revolution. From the Wright Brothers to the SST. From the Toonerville Trolly to the 120-mile-an-hour Northeast Corridor train. From Christopher Columbus to Neil Armstrong. There is another side to this revolution and it is going on every day at our mines and factories. We call it bulk distribution. Perhaps ordinary sounding, but every bit as exciting as those other transportation innovations. Basically, we have gone from bag to bulk, and in the process reached that Last Frontier in manufacturing cost savings. By revitalization of our distribution system, we have made it possible for our mines and factories to realize fully the vast economies of spage-age manufacturing techniques and accomplishments. The pacesetters in this distribution revolution have been you gentlemen, the producers and shippers of dry mineral products. In this area bulk distribution grew up. And here most of the current innovations are being introduced. Management of your industry was early to realize the economic advantages of bulk distribution. Distribution costs of your products comprises a sizeable, portion of the selling price and management is sensitive of any developments which may even slightly reduce the cost of transportation, marketing or the exploration of new frontiers.

Jan 1, 1969

By D. Verhulst

The Altair process digests ilmenite concentrate in high-chloride HC1 solution, with complete dissolution of titanium and iron. The Fe(III) ions are reduced to the ferrous form, and the solution is cooled to produce crystalline ferrous chloride. Titanium is transferred by solvent extraction into a purified, concentrated Ti stream, which is spray-hydrolyzed to produce TiO2 hydrate. The hydrate is further calcined with additives to generate a high-quality pigment. All the chloride streams are recycled. In the original flowsheet, the iron chloride is pyrohydrolyzed by spray roasting to regenerate 18% HCl, which is subsequently converted to HC1 gas and water by pressure-swing distillation. A modified flowsheet includes an alternative to iron chloride spray roasting, producing more concentrated HCl and decreasing the amount of solution to be distilled. Improvements in digestion, solvent extraction and final pigment production are also introduced. A 100 t/y pilot plant is being built and will test the new concepts and confirm the overall water, acid and impurity balances of the process.

Jan 1, 2006

By Jonathan Peck, Jim Gray

"While the mine developer looks for bigger and better orebodies in countries offering lower risks to development capital, the opera-tor of existing mines is looking for bigger and better ways to use his existing resources. Mining operations today utilize a variety of stand-alone systems for planning and managing their operations. In both small and large mines, payroll, accounting, inventory, planning, and engineering requirements are met using a combination of manual and computer-based systems.Technical advances and new enabling technologies are changing how mines are doing business. PC-based systems are allowing small operations to join the larger mines in using advanced computer-based systems. Advanced monitors are being used in maintenance to track, predict and correct the health of production equipment. Production monitoring systems are used to measure the performance of operating equipment and personnel in real time. This detailed information on how much, where, when, and by whom is being used for proactive management and planning. Ultimately, this information can be used to optimize and control the machines’ activities, eventually leading to robotic and autonomous operation of mining equipment.As the use of technology increases in mining, specific information objectives are being met but other problems are being created. The life cycle of technology is small, and as current systems are replaced by newer ones, integration problems and additional end-user training are created. In addition, onboard monitoring systems can create large volumes of data, data which are frequently archived without being analyzed. Mine operators are also duplicating efforts applying new technologies in an effort to be more competitive, but in doing so are creating interfaces which are only compatible with their own facilities. As system development moved from the centralized mainframe computer to the PC environment, the fragmentation of these systems became more pronounced.To efficiently continue in adapting and utilizing advancing technology, the mining industry needs to develop a system architecture that readily integrates as many sub-systems as possible. This will provide a framework for existing system integration and design guide-lines for future development. The Total Mining System (TMS) concept will allow a network of stand-alone functional modules to be readily integrated with minimal effort. This paper will discuss some of the current technologies cur-rently in use in some surface mine operations.In addition, a description of the information system and communications requirements that will be needed to integrate these components in the future, will be discussed."

Jan 1, 1996

By J W. Muir, N Bedford

Hong Kong is one of the most rapidly developing cities in the world. With constant population growth and limited opportunities for space, the development of a fast and effective underground public transportation network is essential. Hong Kong’s Mass Transit Railway (MTR) Corporation is currently undertaking several large underground expansions to its existing network. Much of the excavation will be carried out using the drill and blast excavation method.Drill and blast excavation is common in Hong Kong and with the continued development of underground infrastructure the use of the drill and blast excavation method will increase. Although an effective method of excavation, the blasting vibrations caused during construction can have an adverse impact on surrounding structures and impose disruption on the local community.In order to minimise the risks associated with blasting vibrations, and to demonstrate that the impact on local stakeholders will remain within acceptable limits, it is generally necessary for a contractor to submit a blasting assessment report for approval by government authorities before blasting may commence.Continued increases in population density will force more infrastructure to be constructed underground. Tunnels and caverns are increasingly excavated in closer proximity to critical sensitive receivers. This leads to greater potential impacts on the community, tightening constraints on contractors and a higher level of confidence required for approval authorities. Finding a balance between the needs of the community and rising construction costs becomes more challenging.This paper presents a case study on how the blasting assessment report process has been successfully implemented for a major MTR project situated in a densely developed area of Hong Kong. It describes several methods of assessing blasting vibration impacts, innovative uses of blasting for excavation and the mitigation measures employed to provide the best outcome for all project stakeholders.CITATION:Bedford, N and Muir, J W, 2014. Blasting vibration assessment and innovative blasting methods in high-density urban environments, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 9–20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Harris, J Turner, P Kirsch

Coal mining is recognised globally as a hazardous activity, and as a result operates under high levels of regulatory and public scrutiny while managing a workforce operating in a high-risk environment. Mining companies have developed sophisticated risk assessment procedures, management systems and personnel competency requirements that facilitate the safety and health of employees, and Australia is a world leader in coal mining safety and health.RISKGATE is an Australian Coal Association Research Program funded online platform that delivers broad cross-industry knowledge about current practice in the identification, assessment and management of coal mining risk. Centennial Coal has engaged with the RISKGATE program, managed by the University of Queensland’s Minerals Industry Safety and Health Centre, since its inception in 2010, and contributed topic experts to many modules, including underground topics within the geological and geotechnical domain (strata underground, outburst, coal bumps and bursts, and inrush).In 2013, Centennial Coal experienced significant unexpected strata failure at the Mandalong mine without any personal injury or fatality. This paper presents a case study in the application of RISKGATE to management of this unwanted event, the steps that were implemented, the information that was sourced and the contribution that RISKGATE made to the final outcomes. The Australian coal industry is encouraged to embrace our knowledge platform, and to also openly share processes and practical outcomes that result from integration of RISKGATE in mining operations.CITATION:Harris, J, Turner, J and Kirsch, P, 2014. Case study – application of RISKGATE to managing strata failure in an Australian coalmine, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 55–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By D. Burkhard, E. Herth

"Geologic structure and properties are the primary influences on ground control at San Juan Mine. Geotechnical properties of the coal seam and near seam strata, the presence of above seam sandstone paleochannels and water, are thought to be the leading contributors to ground control issues. It is the confluence of specific geologic conditions rather than isolated features that most often produce adverse conditions. Altering primary support installation and mining practices are done when unfavorable conditions appear during development. Installation of standing support is most often employed when adverse conditions develop at later dates. REGIONAL GEOLOGIC SETTING San Juan Mine is an underground coal mine located on the western flank of the San Juan Basin in northwest New Mexico. The San Juan Basin is contained within the south eastern region of the Colorado Plateau geographic province. The basin contains multiple coal bearing formations and is also a major producer of coalbed methane gas. San Juan Mine is stratigraphically located within the Fruitland Formation. From a prominent monocline marking the western boundary of the basin, the formation dips gently to the east towards the center of the basin. The primary driver for the deposition of coal bearing formations within the basin was the Cretaceous Inland Seaway. Multiple cycles of transgression and regression driven by sea level rise and tectonic subsidence deposited rock types from marine shale’s to terrestrial sandstones. The Sevier Mountains to the west of the seaway likely provided the sediment supply for the Fruitland Formation. During a major cycle of seaward regression, the Pictured Cliffs Sandstone Formation prograded over the marine Lewis Shale. The coal bearing Fruitland Formation followed, being deposited over the Pictured Cliffs. The Fruitland Formation contains numerous coal seams and is approximately 400 ft. thick at San Juan Mine. Fruitland Formation coal seams are numbered in order of superposition. San Juan mines the Fruitland number 8 seam. Dating has placed the age of the seam at approximately 73 to 75 million years [1]. LOCAL GEOLOGIC SETTING The Fruitland 8 coal seam dips approximately 1-3 degrees towards the E-NE. At San Juan Mine, the seam displays a mild plunging, synclinal structure, the axis roughly bisecting the mine from west to east. The number 8 seam consists of five coal benches and four volcanic ash band partings labeled sequentially based on superposition. The lowest portion of the seam is the 8-1 bench, the 8-2 through 8-5 benches following sequentially to the top of the minable seam. Ash band partings are labelled P1 through P4 from bottom to top respectively. The presence of distinctive partings and benches allows for seam definition and aids in identifying mining horizons."

Jan 1, 2016

By A. W. Khair

This paper presents an assessment of modeling techniques in predicting subsidence over longwall areas. Extensive instrumentation, both at the surface and subsurface of three longwall mines in northern West Virginia have been made. Ground movements were monitored during" a three year-period until subsidence ceased in these areas. A comparative analysis of empirical subsidence prediction techniques including, graphical {NCB}, profile function, influence functions (USBM, BAL'S, KNOTHE'S, and zone area) will be presented. A brief geologic and topographic description of each site along with the instrumentation and monitoring program will also be presented.

Jan 1, 1989

By Guowen Dong, Qiyong Li, Qiang Li, Tiejun Chen, Zhihong Wu, Junying Wan

In order to search for a more economical and effective roasting additive for extracting vanadium from stone coal and solve the question of the disposal of PVC waste, PVC waste was proposed as a novel roasting additive to enhance extraction of vanadium from stone coal and realize the comprehensive utilization of resources. By adding this roasting additive, the leaching rate of vanadium reached 94.5% under the conditions that the PVC waste addition was 10 wt%, the roasting temperature was 800 °C, the roasting time was 1 h, the sulfuric acid concentration was 15 vol%, the liquid-to-solid ratio was 1.5 cm3 /g, the leaching temperature was 95 °C, and leaching time was 4 h, which increased by 8.4% compared with that of blank roasting. The thermodynamics calculation showed that the decomposition reaction of mica was performed easier with the participation of HCl produced by pyrolysis of PVC. Meanwhile, The SEM-EDS and aperture test analyses demonstrated that more cracks and voids appeared in the roasted sample by roasting with PVC waste, which could facilitate the release and extraction of vanadium. Additionally, the TG-DSC analyses indicated that PVC could provide large amounts of heat for the roasting process to promote the decarbonization and roasting efficiency of stone coal because of its high calorific value.

By J. E. Chilton

Methanometers with catalytic heat- of-combustion sensors used in coal mines today will read low for flammable gases when oxygen (0,) concentrations are low or when methane (CH,) concentrations are greater than 10%. Thus, these methanometers may not be reliable during operations such as fire fighting or recovery of sealed mines. The U.S. Bureau of Mines developed a total flammable gas detector (TFGD) to measure CH, at concentrations up to 100% and to measure flammable gases in low 0, concentrations. This paper describes the operation and construction of the TFGD and discusses measurements of flammable mine gases obtained from a mine in western Pennsylvania.

Jan 1, 1992

By W. G. Davenport

This chapter shows how flash furnace industrial oxygen and oil requirements are affected by different: (a) product temperatures (b) conductive, convective and radiative heat losses (c) electrical energy inputs (d) hydrocarbon fuels. The calculations of the chapter are all for production of 65% Cu matte from pure CuFeS2 concentrate. Blast temperature is? 298 K throughout.

Jan 1, 2001

By Karel Verscheure

Reliable furnace cooling technology is a domain of increasing concern to the pyrometallurgical industry as it can significantly increase process intensities, productivity and campaign times of furnaces. Although there are many advantages in using cooling systems, they also impose a variety of problems mainly related to safety, heat losses and sustainability of the operations. The choice of cooling system is hence a matter of trade-offs and differs for every metallurgical application. This paper gives a review of different cooling designs used in the ferrous, non-ferrous and alloying industries. Additionally, the paper systematically reviews aspects of materials selection, manufacturing, installation, water quality and furnace monitoring when using water cooled refractories.

Jan 1, 2006

By E. V. Manlapig, David J. Spottiswood

In recent years great advances in the automatic control of flotation plants have been made, mainly due to the development of reliable sensing instruments to monitor process performance and the development of an adequate understanding of system responses to process disturbances. Some of the control strategies used in flotation plants which apply computer control are presented here. These schemes, which involve the control of collector; depressant, frother, and air and pulp level, are analyzed with respect to their control objectives, control variables, and the instrumentation involved. The knowledge gained in understanding these strategies may be applied in the dew and implementation of control system in other concentrators.

Jan 1, 1981

By Karl-H. Daum

Over many decades, numerous feasibility studies have demonstrated, that the production of sulphuric acid remains the most viable option of sulphur recovery from smelter off gas and abatement of SO2 emissions to the atmosphere. This is particularly more pronounced as smaller but more concentrated off-gas flows are to be treated from smelters, and enhanced sulphuric acid processes be-come available. Off-gas handling systems represent a significant capital and operating cost burden to the metallurgical operation. Modern pyrometallurgical smelter processes for sulphide ores based on the use of oxygen-enriched air, produce relatively small off-gas flows with high SO2 concentrations in the smelter gas of 30?60 %-vol. of SO2. This is a prerequisite for substantial cost reductions in the smelter off-gas handling and treatment system. As an alternative to sulphuric acid production, numerous scrubbing concepts with alkali or dual-alkali combinations as well as organic absorbents have been proposed. Also the reduction of the SO2 to elemental sulphur has frequently been studied. Very few of those alternative processes have been built in industrial scale, but all were generally characterized by none sustainable operation due to cost reasons, problems with issues related to chemicals used and by-products or poor availability. Thus the traditional concept of converting the SO2 to sulphuric acid is most common, although regarded as un-economic, but is at least a proven, environmentally sustainable and reliable way of sulphur gas processing. With the high acid price levels these days, operating companies are even able to generate significant revenue with their otherwise ?fatal? acid. Even though smelter gas is available at high SO2 concentrations, in a conventional acid plant one would add large amounts of air to dilute the gas down to a suitable concentration of 12?13 (14) %-vol. SO2. Dealing with higher SO2 concentrations in smelter acid plants is not feasible, as the gas exit temperature of the catalytic oxidation step would exceed the allowable limit for the catalyst. Hence those conventional acid plants are characterised by the use of large equipment, i.e. high capital cost, high energy consumption and limited flexibility. The newly developed LUREC® process can handle off-gas with significantly higher gas concentrations, even in excess of 25 %-vol. SO2. It is entirely based on well-proven equipment and unit operations. The first industrial application, operating with 16?18 %-vol. SO2 will be presented in this paper, along with the fundamentals of the process. It will be demonstrated that the process requires inherently lower capital cost, fewer operating cost, offers better energy recovery and lower emissions as compared to conventional design. While most existing smelter acid plants would have some built-in spare capacity, any significant increase of smelter capacity, say of 30%, can basically not be accommodated without installing an additional parallel new acid plant unit. An add-on LUREC® module can remove any such restriction, while simultaneously de-bottlenecking the existing acid plant. The paper also discusses the present status of the add-on technology for smelter acid plant expansions with respect to technical boundary conditions of different process alternatives as well as economic and environmental aspects. Application of the LUREC® process to modern smelter acid plants operating with high SO2 gas concentration, will lead to a substantial reduction of the specific size of the gas processing equipment and equivalent savings in capital and operating cost. The LUREC® process is patented worldwide by OUTOTEC.

Jan 1, 2009

By Xinlei Jia, Wenming Guo, Yanling Zhang

A large amount of stainless steel dust rich in Fe, Cr, and Ni has been being generated in China. Smelting treatment is accepted as a practical method for the recovery/reutilization of these second resources, during which Fe, Cr, and Ni is reduced into one metal phase and then separated from the residue slag. Based on the typical compositions of stainless steel dust, the residual slag can be termed as CaO-SiO2-MgO-Al2O3 system. In this paper, the activity coefficients of Cr in Fe-Cr-Ni-C (-Si/Al) melt and the properties of CaO-SiO2-MgO-Al2O3- 1%CrO system thermodynamically approached. Then, in laboratory experiments, the recovery ratios of Cr and its distribution behaviors between Fe-Cr-Ni-C melt and CaO-SiO2-MgO-Al2O3 slag system were examined.

Jan 1, 2015

By Hye-Sung Kim, Dong-Wha Kum, Gyeungho Kim

"Mechanical alloying is an effective way to finely distribute inert dispersoids in AI-TM (TM is a transition metal element) systems. It is considered that high melting point aluminides are formed by precipitation from the supersaturated aluminum matrix. The analysis is based on the fact that much higher content of TM than the solubility limit can be dissolved in alpha aluminum during the high energy ball milling. Nonetheless, the role of undissolved TM particles affecting the formation of aluminides is not suitably considered. In this paper, authors present experimental observation on the formation of Ab3Ti particles from mechanically alloyed AI-Ti alloys in the hyper-peritectic region. This study showed that, in the mechanically alloyed AI-20wt%Ti specimen, intermediate phase of cubic Ab3Ti and tetragonal AIz4Tis formed at 300 - 400°C and 400 - 500°C, respectively, before the MA-state reaches to the global equilibrium at higher temperatures. The formation behavior of Lh- Ab3Ti is interpreted by interdiffusion of Al and Ti in solid state based on the fact that large amount of nano-sized Ti particles exist in the milled powder. Present analysis indicated undissolved Ti particles of nanosize should have played an important role initiating the formation of Ab3Ti phase during annealing.IntroductionInterest in the hyper-peritectic AI-Ti alloys is based on industrial demand for high-modulus and high-temperature aluminum alloys. Earlier works on hyper-peritectic AI-Ti alloys with 4 to 12wt%Ti show that these alloys are strong at ambient temperature and maintain high strength above 300°C when titanium-trialuminide (e.g., Ab3Ti) is finely distributed in the aluminum matrix [1,2]. High melting point and high stiffness with low density of AbTi make the AI-Ti alloys strong with greater thermal stability while keeping weight savings as much as possible. Titanium in aluminum shares other merits of transition metal additions because Ti solubility in Al is low (i.e., 1.l5wt%Ti at 665°C and virtually zero below 400°C), and fine dispersion of Ab3Ti particles is readily accomplished and resists grain coarsening effectively."

Jan 1, 1996

At the Waikato North Head Ironsand operation, NZ Steel Mining Ltd is using a Bucket Wheel Excavator û shiftable conveyor mining system to excavate Titanomagnetite bearing sand and clay. The system utilises two Bucket Wheel Excavators with a two level shiftable bench conveyor and common trunk conveyor to deliver the material to a processing plant. The system was commissioned in November 1984 and has proved itself to be a high capacity, low cost method of excavating. Techniques of handling high sand faces have been developed and the conveyor layouts are going through a process of change to cope with the variable geo technical conditions and remain within: the characteristics of the excavators. The safety requirements for operating the system have been of a high standard and the experience has increased the confidence of the Company and the Mines Department Inspector's, for the first Bucket Wheel Excavator Mining system in New Zealand.

Jan 1, 1986

By E. E. Cudby

"FOLLOWING the Leduc discovery •by Imperial Oil in 1947, The California Standard Company began to acquire land in the area immediately west of Edmonton and in line with the Leduc reef trend (Figure 1).The California Standard Winter-burn Province No. 1 in Lsd. 10, Section 4, Township 53, Range 25, West 4th, which was spudded, on the basis of a seismic anomaly, in December, 1949, failed to find reef. This well was located on the eastern .edge of a large land block which California Standard and Imperial Oil had pooled as a joint venture, with California Standard a:s the operator (Figure 2).The culmination •of an extensive exploration and land aquisition programme was the drilling of the California Standard-Acheson Province No. 1 well .in Lsd. 13, Section 2, Township 53, Range 26, West 4th. On August 24th, 1950, a drill stem test was run in the D-3 zone which had been encountered at 4,969 feet, and a flow rate of 702 barrels per day •of 36° gravity oil was obtained. Just previously, Imperial Oil had completed a similar programme in the Stony Plain Reserve with the swabbing-in of Imperial Stony Plain No. 1. These two discoveries set off a drilling programme to determine the extent and value of the oil accumulation.Subsequent drilling of wells some successful .and others not by several other companies as well as California Standard bias, .to date, still left much to be determined as to the approximate delineation of the productive limits of the Ache-son-Stony Plain area. However, to August 31st, 1951, there were twenty-one D-3 producers north of the reserve and three in the Stony Plain Reserve."

Jan 1, 1952

By W. Fergusson

This paper takes a look at the use of rubber to provide corrosion resistance and wear resistance in the mining industry. The longer life and reduced down time involved with the use of rubber are stressed, and examples are given of applications in grinding mills, skips, discharge chutes and screens.

Jan 1, 1979

AT THE beginning of May the German government offered to the French and Belgians the payment of 30 billion .gold marks as indemnity, accom-panied by rather involved terms, among which was the ability of the Germans to finance the foreign loan. This offer was promptly and summarily refused by the French and Belgians. Since then there have been more palavers between the two parties, while the occupation of the Ruhr continued without especial incident, except some socialist riots and workmen's strikes. The renewed conference between the Allies and the Turks at Lausanne continued, without apparently getting anywhere. The Turks demanded an indemnity from the Greeks, which the latter refused to pay, threatening a resumption of hostilities rather than to do so. A. Bonar Law, the British premier, resigned his office soon after the middle of May, owing to poor health. The King appointed Stanley Baldwin as his successor. This. Attainment to the premiership of Great Britain by a business man is a noteworthy event. It is, moreover, to be remarked that Mr. Baldwin is personally acquainted with America and is well known to be a friend to Americans. The Irish rebellion came to an end. Economically there was some improvement in the situation in Great Britain during May, which was reflected in diminution in the number of unemployed. Nevertheless the aggregate of the unemployed in Great Britain continues at a very high figure. In Germany there has been an increase in the number of unemployed ever since the French occupation of the Ruhr, which naturally has been choking German industry. Previous to this the percentage of unemploy-ment among German workers had been low ever since the Armistice. A noteworthy domestic event was the non-stop flight of an airplane, May 2-3, bearing two aviators from New York to San Diego, California, in about 27 hours.

Jan 5, 1923