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By D. M. Doyle

A study of the various components contributing to energy costs and their relationships to generally trended operating data, such as tonnage, operating costs, etc., over progressively shorter time periods provides information for an energy audit. A study of annual data gives some insight into the importance of various energy components. As the time frame of the study progresses through monthly, daily and, finally, into quarter hourly data, the variations become more evident and, most important, strategies develop to minimize energy costs. The results of an audit conducted during the summer of 1978 at Wesfrob Mines Limited are reported to illustrate this important phase, prerequisite to a meaningful energy cost avoidance program. The balance of the paper deals with the energy conservation program at Falconbridge Nickel Mines Limited's Sudbury operations, the metering and control equipment, the commitment, the new energy accounting practices and, lastly, the policies. Examples of successful energy conservation endeavours include automatic peak electrical load control, waste heat recovery from mine air and compressor cooling water, energy reductions resulting from lower building temperatures and curtailment of idling loads. The use of pulse meters to measure the flow of gas, steam, compressed air and electrical energy, with their signals interfaced to process computers, allows monthly, daily and, if necessary, immediate reporting of energy and energy per unit of production information The program so reported at Falconbridge's Sudbury Operations is credited with an annual cost avoidance of .9 million dollars in a 14.0-million-dollar annual energy account

Jan 1, 1979

By Willie van Niekerk

As mining projects get larger and more complex there is a need to examine the use of project management techniques developed for large construction projects in order to ensure completion of the project on time and budget. In recent years the construction/civil industry has sought new methods to ensure that multimillion dollar projects involving multiple contractors, working in an increasingly legislated work environment, are delivered to the clients satisfaction. The paper describes these methods, which range from program management to systems and tools to gather all project information such as schedule and cost, and relates how these can be applied to large international mining projects. The paper also describes the benefits that an independent project manager can bring to a client or owner?s team by setting up the relevant organization and controls together with the appropriate contract and procurement strategy.

May 1, 2009

By Chester M. F. Peters

INTRODUCTION There has been considerable discussion in recent years of the strained relations between owners, engineers and contractors caused by the rapid increase in costly litigation in underground excavation due to construction claims. These time consuming claims are not to the best interests of the industry. It has been a conclusion of some of the concerned parties that there could be a substantial reduction in these claims if a mutual respect for each other's roles could be maintained along with a practical contractual arrangement for sharing the risks of the unforeseen costs inherent in the business. This paper will touch on the overall problem of these relationships, but confine the major discussion to the role of geology in claims and, in particular, changed conditions claims, since they form the base for the bulk of those involving geology. Geologists can make a major contribution to the reduction of these claims if their particular abilities are recognized and used properly. CLAIMS AND GEOLOGICAL RISKS The tunnel contractor is strictly bound by the contract he signs, and the risks he assumes thereby must be priced. The most important variable factor on which he must base his price is the geologic data provided and his interpretation of it. If this data does not give a clear picture of the conditions, making it impossible to price

Jan 1, 1974

By Pafos Busch, Martin Fischer, Johannes Jaeger

The Spitzenberg Tunnel is a 600 m (1,970 ft) long twin tube motorway tunnel on Germany’s Autobahn A44 between Kassel and Eisenach. Since flexibility was considered to be very important in the continuously changing geological conditions, NATM was chosen as the construction method. When passing an old quarry with only 1,80 m (6 ft) of overburden, the excavation works became extraordinarily challenging. This paper not only describes the special methods, like double sidewall drifts and pipe umbrellas applied in this zone but also highlights the cooperation between the parties involved, which in combination made the project a joint success.

Jun 13, 2021

By R. M. Bird

FEW persons outside of the foundry trade have any conception of the great variety of sands now regularly specified and furnished, nor of the differences in foundry practice frequently resulting from apparently minor changes in sands. Conditions in each locality where the sands are mined and prepared necessitate special equipment designed to perform the work efficiently. The description that follows of the foundry sand producing operations is typical of the areas in New York and New Jersey, and particularly refers to the operations of the George F. Pettinos Co.

Jan 1, 1926

By L. F. Albert

The paper describes solutions given to foundation problems during the reconstruction of a power plant set on fire, located adjacent to several still Working Units. After a detailed site and laboratory investigation, it was decided that it could be possible to include within the new foundations the preexisting cast in situ driven piles with enlarged base 50 cm in diameter and let them work with new 41 cm driven, cast in situ piles without enlarged base. Demolition of existing caps was carried out with expansive mortar in order to avoid any possible damage to piles, whose actual conditions were checked by several load tests. New piles were designed to support service load by shaft resistance, in order to limit total and differential settlement. When piles had to be driven adjacent to nearby structures, measurements of peak soil particles velocity were carried out while driving piles at decreasing distance from critical locations. By preboring most of the upper clay layer it was possible to reduce within safe limits for structures the induced vibrations.

Jan 1, 1989

By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of the Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper, in which he presents his own A factor.Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blasthole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, eg in conjunction with image-based fragmentation measurements or crusher modelling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function, such as in the KCO model.The mean to median issue is investigated in some detail and it is found that using x50 instead of the mean:has a sounder theoretical backgroundis less prone to errorsis not contradicted by the original Soviet data.It is finally suggested that future work on fragmentation prediction equations focus on the use of distribution independent quantities like percentiles, eg x50, x20 and x80. Some previous work in this direction is briefly analysed and one consequence is that the n-value of the Kuz-Ram model should depend on specific charge.CITATION:Ouchterlony, F, 2015. The median versus the mean fragment size and other issues with the Kuz-Ram model, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 109–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Exploration of new resources and development of new equipment and designs are an ever changing facet of mining. New equipment to handle specialized operations is being developed and new techniques for its use explored. One such system is reviewed. Another is a potential system for handling the thinner stray coal seams between the more profitable thick seams. The availability of federal coal leases in the West is reviewed and current planning discussed. Gulf Coast lignites have been of much interest in recent months and are overviewed.

Jan 1, 1979

By R. A. Jankowski

The U.S. Bureau of Mines (USBM) conducted a series of laboratory tests to investigate the effectiveness of using a flooded-bed scrubber with exhaust ventilation in deep-cut faces of up to 12.2 m in length. An experimental test program to determine the impact on respirable dust levels resulting from changes in face airflow, curtain setback distance, operator positioning, and operating parameters of the external spray system on the miner was completed. Gravimetric sampling was conducted in the immediate return and at three sampling locations on the off-curtain side of the entry. Statistically significant differences in dust levels on the order of 0.5 to 1.2 mg/m3 were observed between specific sampling locations and changes in several test parameters. Dust sampling results indicated that a flooded-bed scrubber and exhaust ventilation can be a viable dust control system for extracting deep cuts up to 12.2 m in length. The impact on methane was not evaluated.

Feb 24, 1997

By Paul M. Tyler

The technology of clay and the manufacture of ceramic products therefrom, and also the clay resources of most of the individual States, are already covered by a voluminous literature. The present resume touches these matters only briefly; its purpose is essentially to bring together in small compass certain of the elementary factors affecting the potential commercial value of a clay deposit. In its preparation the author made extensive use of the annual chapters on Clay in Mineral Resources of the United States and in the two annual issues of the Minerals. Yearbook that succeeded them. For careful review and constructive criticism of the manuscript, the author is indebted to Hewitt Wilson. GENERAL DESCRIPTION The term ?clay? includes a great variety of substances that may differ widely in chemical mineralogical and physical properties. No two clays are exactly alike. All of them however, have the prominent characteristic of becoming more or less plastic when wet. Nearly all of the useful clays can be molded into articles, will hold their shape while being dried, and can be converted into a hard, rocklike substance by heat. Clay may, and in fact usually does, consist of a number of minerals among the commonest of which are kaolinite, quartz, feldspar, iron oxides, mica, bauxite, calcite, and manganese oxides. Organic matter is often present. Pure kaolinite, which has the formula A1203. 2 SiO2. 2H2O, is ordinarily, considered to be the parent "clay substance," butt most clays contain other hydrated mixtures of alumina and silica (aluminosilicic acids) along with indefinite amounts of sand and other nonessential minerals3/ Even, this so-called inert matter affects the plasticity, drying shrinkage, ease of drying, and final density, and at high temperatures may react chemically with the clay substance.

Jan 1, 1929

By S Maryati

Surface mining activities disturb large areas, produce great sediment loads and tend to be a source of water pollution if they are not managed properly. Coal mining in Indonesia has a very high risk of soil erosion because the coal mining areas are generally located in tropical areas with a high average of rainfall (4000 - 6000 mm/year) and use surface mining methods. The main factors affecting erosion risk are climate, soil type, topography, vegetation cover and management factors. Thus, the monitoring of erosion risk in mining areas is very important due to the characteristics of coal mining in Indonesia. The objective of this research is to determine the ability of satellite images (remote sensing data) and geographic information systems (GIS) to provide an accurate and up to date spatial database for the monitoring of erosion risk in surface coal mining areas using the Universal Soil Loss Equation (USLE) method.The erosion risk analysis and spatial data processing are generated by the ArcGIS 9.3 software and need several data, namely: an erosivity map, erodibility map, a slope map, vegetation index map and land management or land cover map. The erosivity map is derived from the rainfall data, whereas the erodibility map is derived from the soil map. The slope map is derived from the SRTM-DEM (Shuttle Radar Topography Mission-Digital Elevation Model) and processed using 3D analyst tools. Furthermore, the vegetation index map and land cover map are derived from a satellite image using digital image processing techniques.This preliminary study produced results that show soil erosion monitoring, which is integrated with remote sensing and GIS technologies, has great potential for producing accurate, advance, and low cost erosion risk maps in coal mining areas. This map is very important for getting spatial distributions of the erosion and useful for developing erosion management plans.

Nov 22, 2011

By A. Habibi

A study has been undertaken on two 1.12 m diameter industrial booster fans operating under different blade settings powered by a 1200 rpm motor at the Missouri University of Science and Technology. The fans total pressure varies up to 1kPa forcingup to 25 m3/s through the workings. A pressure-quantity survey has been conducted inby and outby the booster fans with different blade settings. The study uses a variable speed drive (VFD) to determine the effect of rotational frequency on the system. The pressure drop across the bulkheads has been monitored during the experiments. The fans were operated with various blade settings to determine the optimal scenario that maintains the maximum airflow quantity and the lowest power demand at a particular ventilation station. Five scenarios were conducted with different blade setting and mostly with two different speeds. The experimental results show that alteration of fans? speeds by use of a VFD unit can reduce power consumption while maintaining airflow requirements. With the flow rate forced through the mine by the surface fan the blade settings 4 and 5 were determined as possible alternative for the mine ventilation system. In scenario 4, the airflow at the particular ventilation station for a number of speeds is over 20m3/s. The power consumption at 1080 rpm was measured to be 20.1 kW compared to 25.5 kW at 1200 rpm. The operating cost would be significantly less at lower speeds. Scenario 5 is the alternative making use of both booster fans and the main fan in series that meets the minimum airflow requirement at the particular ventilation station along with minimum power consumption. Reducing both booster fans speeds to 1054 rpm results in power consumption of both together dropping to 11.8 kW. Therefore blade setting 5 using two booster fans was determined to be the optimal setting. Separately it was determined that the combination with use of only one booster fan, the West booster fan, running in series with the main fan is the overall optimal scenario. The power consumption of the West booster fan was calculated to be 8.8 kW at 860 rpm with the minimum airflow requirement being met. Computational fluid dynamics is used for analyzing three dimensional flow structures in time domain and calculating the corresponding unsteady pressure fluctuations. The sliding and dynamic mesh techniques were used to study the unsteady flow interaction arising due to the rotation of the fan blades. The numerical predictions of the variables in the form of velocity vectors and contour plots detailing the flow characteristics are then analyzed according to the known physical situation and existing experimental data.

Feb 27, 2013

By V. O. Tenorio, J. Puell

"Dump design is critical to effective mine planning in large scale open pit mines. Capital and haulage costs are considerable from early stages and through the life-of-mine as these dumps gradually become immense structures. Delivered mining rates, as well as certain spatial and physical constraints, provide a set of parameters of mathematical and economic relationship that creates opportunities for modeling and thus facilitates the measuring and optimization of ultimate dump design by using programming and empirical techniques while achieving economic objectives. This paper presents a methodology to optimize the ultimate dump design by minimizing its total dumping costs. The methodology consists of the formulation of a generalized model based on the relationship of the main dump parameters, followed by the use of linear programming to find the solution that minimizes the haulage total cost, and finally through a series of iterations, modifies the preliminary solution by projecting it to the topography and creating the ultimate dump design. A case study applied to a waste dump exemplifies this methodology. INTRODUCTION Open pit mine operations move large amounts of material on a daily basis from the shovel faces to the appropriate destination points. Hustrulid et al. identified three major destination places where the material receives downstream treatment after its delivery: mill processing, leaching dumps, and waste rock dumps [1]. The corresponding destination is given by a cut-off grade criteria, ore type, and the possibility of obtaining the maximum metal recovery. Dump leaching technologies have developed substantially since 1975 [2], and have enabled mining facilities to beneficiate low grade sulfide and oxide ores. As a consequence, the number of active dumps have increased since then and the entire mine configuration, which is limited in itself, has changed. The proper location, design, and construction of a mine dump must serve the safety, environmental and economic goals of the long-range mine plans. Therefore, an optimized use of the available surface area in the mine is highly desired."

Jan 1, 2018

By T Elkington, A Finch

The theory of constraints (TOC) is a business improvement method that focuses on exploiting a business’s bottleneck to deliver the highest possible profit. Early applications were mostly in the manufacturing industry; however, the theory in itself is completely generic and has now been applied widely in other industries such as services, retail, software and distribution, amongst others. The intent of the approach is attractive – it focuses on the ‘silver bullet’ rather than ‘death by a hundred projects’, and it focuses on growth rather than cost cutting. Application within the mining industry has been limited to date, although there are a few applications emerging. This paper discusses how TOC can be applied to maximise value during the project planning phase and how to maximise profits when the mine is operational. The paper uses two case studies to illustrate the approach. Case study 1 uses the approach to improve tactical mine planning, which delivers an increase in revenue of 58 per cent. The second case study is a strategic mine planning example that delivers an increase in value of 77 per cent.CITATION:Finch, A and Elkington, T, 2014. Application of the theory of constraints to strategic and tactical mine planning, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 129–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By A P. Brown

Access arrangements required with landowners and occupiers; relaxation on size of permits; lack of confidentiality for information provided; one-stop shop under RMA, removal of standing; plethora of controls; post-closure; funding for long-term security.

Jan 1, 1997

By A. D. Mukherjee, H. N. Bhattacharya

Middle Proterozoic sulphide ore mineralisation occurs in isolated blocks of the NE-SW trending Delhi fold belt composed of Delhi Supergroup rocks. The Ajari-Basantgarh-Pipela belt forms part of the longest, widest and westernmost tectonic unit of the Delhi fold belt and consists of amphibolites, metapelites, quartzites and carbonates. The metapelite lenses and associated amphibolites host pyritic copper mineralisation. Mineralisation takes the form of sheet-like bodies consisting of ore lenses of various sizes interlayered with host or associated rocks. Massive, banded and disseminated varieties of ore are found. Pyrite is dominant with subordinate chalcopyrite and sphalerite. Pyrrhotite, galena, cubanite, mackinawite, marcasite and freibergite constitute the minor minerals. The characteristic features of the ores suggest a possible correlation with Besshi-type deposits, and the closely associated amphibolites are interpreted as low-K tholeiites of a fore-arc setting

Jun 19, 1905

By J. Alton Burks

When acoustical materials are used in a mining environment for noise control purposes, they are subject to environmental deterioration from hydraulic fluid, moisture, and dust. These and other factors can cause physical degradation of the material, which can lessen its ability to absorb sound. In this study, the Bureau of Mines measured the sound absorption properties of 16 different acoustical materials after 4 sample treatments: (1) being kept clean and dry (as received from the supplier), as a control or reference standard, (2) immersion in water and draining, (3) immersion in lOO-pct-petroleum-type hydraulic fluid and draining, and (4) exposure in a coal mine. The last three treatments were used to approximate the type of physical degradation that can be experienced in actual use. The impedance tube or standing wave method was used to measure the normal absorption coefficient. It was found that the absorption coefficient of most materials was adversely affected by the retention of either oil or water, with oil having the greater effect. The only class of materials that was affected by neither oil nor water was neoprene foam.

Jan 1, 1990

The NIOSH suite of coal mine ground control software addresses nearly every aspect of coal mine ground control planning, including geologic characterization, mine layout, pillar design, and support selection. Mine planners who use the soft-ware have access to the knowledge gained during years of NIOSH research—packaged in a simple, easy-to-use format. Several of these software packages have recently been updated and improved. Analysis of Roof Bolt Systems (ARBS) (Figure 1) helps select the proper roof bolt system design from the immense variety of available bolt types and patterns. It was developed from statistical analysis of extensive bolt performance and roof fall data. New features in Version 2 include— • The capability to analyze roof bolt systems that use two types of bolts; and • A roof support cost module that estimates the total in-stalled cost of different patterns, considering the costs of consumables, labor, maintenance, and other factors. The Support Technology Optimization Program (STOP) (Figure 2) can be used to make judgments regarding which secondary support system will be the most effective in a particular mine condition and to evaluate the advantages or dis-advantages of alternative support systems. Version 3.0 includes additional improvements: • Supports with large load-shedding following yielding can be designed based on the peak loading capability as well as the residual loading capability; • Seven new support systems have been added to the program; and • Easier access to photo gallery has been provided. The Coal Mine Roof Rating (CMRR) replaces com-plicated geologic information with a simple numerical rating that mine planners can use in many ground control applications. The CMRR can be readily integrated into a geologic exploration program, and the software package is capable of generating an AutoCAD CMRR "layer." Version 1.2 contains— • The complete CMRR database with more than 250 ratings obtained from 70 different U.S. coal seams; and • An all-new "Help" file that clearly explains all aspects of the program. Analysis of Horizontal Stress in Mining (AHSM) can help find the optimum mine layouts for control of horizontal stress. It can be used to analyze both development and longwall retreat designs, and it shows how the stress condition varies as the entry, crosscut, and panel orientations are changed. Version 2 features— • Improved graphics that enable the user to observe the effect of design changes without adjusting the display on the computer screen; and • Resource files containing information on stress map-ping, advance-and-relieve mining, stress measurements in U.S. coal mines, and other topics. [ ]

Jan 4, 2006

By J. Hartikainen

Kemi cardboard mill is founded on the alluvial bed of Kemi river at the north-eastern cost of Botnic Culf in Northern Finland. The alluvium consists of sandy and silty layers underlain by thick medium dense silty moraine layer. The first cardboard machine, having a belt width of 7,4 m, was constructed in 1972 on 7,5 to 9,5 m long wedge-shaped precast driven piles. Because of the excessive differential settlements and sometimes unexpected dynamic malfunctioning of the machine it was decided to strengthen the foundation before installing the partly new machine and increasing the running speed from 500 to 750 m/min. Piling was done under extremly strick limitations concerning space, vibrations, settlements, dust etc. Extra vertical support was made by using 23...25 long x-form steel piles driven by compressed air pile hammer down to rock. The piles were held together with old piles by a conctrete frame with diagonals, which made the total system - machine - foundation frame, piles and ground - ridgid enough to avoid resonance during dynamic loading.

Jan 1, 2010

By Ali Hasham

Reduction rates of FeO in CaO-SiO2-Al2O3 slags by Fe-C melts have been investigated experimentally at 1723 K. The rates were estimated using experimentally determined CO(g) evolution rates. Flash X-ray images were employed to visualize the behavior of the melt-slag interface during the reactions. The influence of melt interface was examined by conducting two types of experiments - (i) dropping one (or several) Fe-C droplet(s) weighing 2 g into the molten slag bath, and (ii) dropping a small amount (10-30 g) of slag onto a Fe-C melt weighing 400 g. The rates from both types of experiments were compared and analyzed to determine the rate limiting steps. It was established that neither the carbon transport in the Fe-C melt, nor the transport of gas species in the gas film adjacent to Fe-C melt was responsible in limiting the reaction rate. It is possible that the slag phase mass transport may be controlling the initial reduction rate in the droplet experiments. However, a, different mechanism was responsible in limiting the reduction reaction when the overall %C in the droplets fell to about 2-3.

Jan 1, 1992