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By Suman Giri

Non-Intrusive Load Monitoring (NILM) is a method of extracting appliance-level power consumption information from aggregate circuit-level data with the goal of giving users feedback regarding their energy consumption so they can take control of their consumption habits. In this paper, we present a novel algorithm for classification of on and off states of appliances. We compare the performance of our algorithm in on state detection with a pervious paper that evaluated the same dataset and show that it performs up to 13% better. We also present the results of a case study where we collected data for different modes of a cooktop, microwave and dishwasher and used our algorithms to perform power estimation. The error on ten different setups in the test bed ranges from 1% to 32%. We discuss our results and lay out ideas for future work.

Aug 1, 2013

By Richard Q. Fox, Joe L. Pinson

This paper provides guidelines jo1• analyzing and selecting electric power demand controlled. Error calculations, load selections and timing criteria are identified as the three key functions which affect the suitability of a demand controller for any particular application. The advantages of simulating the demand control application on a computer are described, and applications of a demand controller to an iron ore concentrator and a copper refinery are shown. Finally, the paper studies the return on investment for a demand controller.

Jan 1, 1976

By J. Fox, K. Kocsis

"Planning for sustainable cooling potential requires protected space to successfully maintain chilled propylene glycol in storage until needed. Stored propylene glycol should be judiciously cared for, safely kept from the ill effects of heat, in order to remain useful for bulk air cooling. Minimizing the chilled temperature of the propylene glycol reservoir tanks means that atmospheric conditions will be monitored closely during the chilling phase. Storage facilities would maintain restricted airflow while minimizing possibilities for heat transfer during the storage phase. Sustainable cooling systems could reduce or eliminate the need for mechanical cooling if installed with favorable conditions. Storing the cooling potential from the winter months is what this new design is all about.INTRODUCTIONIn most subsurface, bulk air-cooling methods, the main source of potential cooling energy comes from cold-water applications. This paper investigates the practical use of harvested, chilled propylene glycol as the source of cooling potential. Propylene glycol is chosen as the cooling storage liquid refrigerant since its chemical make-up is intrinsically safe to fresh water supplies and will not harm underground workers should a leak occur in the closed cooling circuit. Harvesting the cold of winter is a meaningless endeavor without proper thermal planning for the storage of the cooling potential in cold refrigerant.PROPYLENE GLYCOL STORAGE RESERVOIRA new design for a closed refrigerant bulk air cooling system employing propylene glycol as the refrigerant is presented as the main design topic of this paper. Given that a deep and hot mine will need to be considered safe and productive, a cost-effective cooling system is desired in order for the mining operation to be considered sustainable. For underground mines at northern latitudes, cooling applied to fresh air is only required 3 to 4 months of the year. During winter, ambient atmospheric conditions can be harnessed and stored for use at a later time.The basis of this sustainable design uses very cold ambient air that is circulated around galvanized steel refrigerant reservoir tanks. The propylene glycol reservoir tanks are arranged in a concrete walled pit, or tank farm, excavated in bedrock. During the coldest months, the tank farm will be exposed to the open air. As the seasons change the tank farm will be covered with insulation to maintain the maximum cooling potential for use during the warmest months of the year."

Jan 1, 2019

By Benoît Valley

Optimization of the mining sequence in terms of economics (maximizing net present value) often leads to multi-front mining methods generating pillars. Significant resources are tied up in these pillars, but mining them is often challenging. In order to improve our understanding of rock mass behaviour while extracting these pillars, an extensive monitoring program has been designed and implemented at Vale?s Coleman mine (Sudbury, Canada). The program focuses on existing and new technologies that have potential for monitoring deformation and rock mass property changes. It includes both active and passive methods: gravimeters, multi-point borehole extensometers, fiber optic strain meters, fixed and portable three-component seismic arrays, borehole imaging and sonic logging, and, repeated LiDAR surveys. This paper reports results from an initial project phase, when only a small amount of mining has taken place. The goal was to test and compare technologies in order to assess their sensitivity, accuracy, repeatability and suitability for underground mining conditions. Value is gained by having a broad range of monitoring devices running side by side, enabling comparisons and benchmarking.

Jun 1, 2012

By Charles J. Zablocki, Robert J. Kamilli

"Buried, possibly mineralized granite cupolas at the Silsilah tin deposit in Saudi Arabia (lat. 26°06' N, long. 42°40' E) have been successfully located using a closely spaced electric-field-ratio profiling technique. In this study, electrical fields at 27 and 270 Hz across grounded electrodes spaced 50 m apart were measured along six traverses. This method is interpretable by inspection, unlike the dipole-dipole technique, which requires mathematical modeling for interpretation.In the study area, the technique allowed the authors to identify and distinguish among unroofed granite cupolas, cupolas with their aplite-pegmatite apical contact zones intact, strong (quartz-rich) and weak (relatively quartz-poor) greisens, dikes, faults, and pervasively argillized rocks.This method should be useful in the valuation of other shallow mineral prospects in similar settings in other parts of the world, especially deposits for which the location of vertical contrasts is important, such as veins or mineralized zones associated with the apexes of small igneous cupolas."

Jan 1, 1993

By T. Niedoba

Coal as an energetic raw material is characterized by many features that determine its quality. The data concerning coal are usually treated as independent values, despite the fact that this kind of approach is not always appropriate. In the paper the dependencies between sulfur contents and volatile components in coal and particle size and density were analyzed. The method of ordinary kriging is applied to experimental data to describe this relationship; this method can be used for particles of any size and density. An example of the application of this technique is presented for energetic coal Type 31, originating from one of the Polish hard coal mines in Upper Silesia. Results from ordinary kriging are in good agreement with experimental results. Similar analyses can be performed for other properties of coal material, such as ash content, Roga number, and moisture. On the basis of the data obtained by ordinary kriging, a more comprehensive multidimensional model is described, which can characterize certain deposits or strata from which the analyzed materials originate. This is superior to basing the model only on experimental data, which often is limited by size of the sample. The results obtained by ordinary kriging applied to various types of coal would allow more precise analysis of individual properties of the studied materials and increase the ability to determine significant differences between them. This method can be also applied to other types of mineral raw materials, such as copper ore.

Aug 1, 2013

By P. Hajiani

"Feasible and sustainable separation of lanthanides outside of China has been a dilemma for the past few years. The present technique uses REE electrophoretic mobility (Ui) variation in an electrical field to separate them. The present invention relates to a system and a method to separate and refine rare earth elements/compounds produced in hydrometallurgical processes while they are dissolved in an acidic medium, without any intermediate precipitation step. This process uses free-flow electrophoresis to isolate REE from the concentrate simultaneously without any pre-treatment or intermediate steps related to the nature of elements.INTRODUCTIONRare earth elements (REE) invariably occur together in nature, and any given mineral contains several or most of them. Production of high purity individual rare earth (RE) elements/compounds from their ores generally requires two stages of processing, including mineral processing and hydrometallurgy.Depending on the ore, mineral processing and hydrometallurgy treatment of the ore before REEs purification is relatively simple and quite achievable though conventional methods. However, producing individual REE from mixed REs compounds is tremendously tedious. RE processing often requires dozens of steps, each resulting in minute improvement in the complex RE streams. Separating and extracting a single REE requires a great deal of time, resources, and expertise. Today, advanced RE refinery facilities cost hundreds of millions of dollars to build. The high purity RE concentrates are separated into individual REE using solvent-based or ion exchange methods. Although there are several techniques to separate REEs, most of them suffer from different types of drawbacks. For instance, solvent extraction requires a great number of steps to achieve high purity REEs. The process which uses ion-exchanger for separation and refinery operates with low REE concentration in solution which leads to very large liquid volume quantity, bulky tanks, dehydrators, pumps, etc. The low concentration will adversely affect the water consumption as well as other chemicals. Similar chemical properties of those three valent elements do not allow them to be isolated easily one from one another using conventional separation techniques. Solvent extraction has been successfully applied for rare-earth refining (lanthanide, scandium and yttrium) for the past few decades in China. Since then, efforts have been dedicated to develop other techniques which could be applied industrially around the world."

Jan 1, 2016

By M. Rafiee

Indoor physical security, as a perpetual and multi-layered phenomenon, is a timeintensive and labor-consuming task. Various technologies have been leveraged to develop automatic access control, intrusion detection, or video monitoring systems. Video surveillance has been significantly enhanced by the advent of Pan-Tilt-Zoom (PTZ) cameras and advanced video processing, which together enable effective monitoring and recording. The development of ubiquitous object identification and tracking technologies provide the opportunity to accomplish automatic access control and tracking. Intrusion detection has also become possible through deploying networks of motion sensors for alerting about abnormal behaviors. However, each of the above-mentioned technologies has its own limitations. This paper presents a fully automated indoor security solution that leverages an Ultra-wideband (UWB) Real-Time Locating System (RTLS), PTZ surveillance cameras and a Building Information Model (BIM) as three sources of environmental data. Providing authorized persons with UWB tags, unauthorized intruders are distinguished as the mismatch observed between the detected tag owners and the persons detected in the video, and intrusion alert is generated. PTZ cameras allow for wide-area monitoring and motion-based recording. Furthermore, the BIM is used for space modeling and mapping the locations of intruders in the building. Fusing UWB tracking, video and spatial data can automate the entire security procedure from access control to intrusion alerting and behavior monitoring. Other benefits of the proposed method include higher accuracy and robustness, more complex query processing, and interoperability with other BIM-based solutions. A prototype system is implemented that demonstrates the feasibility of the proposed method.

Aug 1, 2013

By J. Someehneshin

Nowadays along with population growth, industry development, consumption of mineral resources and the fact that the reserves on hand are running out, the depth of surface and underground mines for further exploitation are increasing. During recent years, in underground mining, the block caving method for low-grade and large-scale deposits has shown a growing rate of application. This method is very cost effective and economically affordable. The dimensions of blocks are one of the most important parameters which should be taken into account since it has been proved to have a great deal of effect on technical issues such as commencement of caving and mine design. Proper calculation of the length and width for a block in this method leads to proper caving and discharging which are the most important stages. Therefore, in this method, the calculation of the optimized dimensions (length and width) of blocks is not only important but also directly helps the productivity of extraction. In this study, firstly for the purpose of facilitation, some assumptions were considered and having used these assumptions for estimation of optimized length and width of block, a relationship based on rock mechanics and physics was explored. Furthermore, some necessary details were added to the said relationship and finally, it was transformed into an inequality. Solving this inequality provides us with the optimized length and width of the block. The explored relationship was analyzed with MATLAB software and the graphs thereof were drawn. In these graphs, each time one of the input parameters has been drawn up in a logical range so that it could be compared with previous states.

Aug 1, 2013

By Yan Yang

The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year. This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant. Major modifications and improvements on the SABC circuit are described in the paper, including: 1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball. 2. Effect of milling operation parameters on milling efficiency. 3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput. 4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput. With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed.

Jan 1, 2012

By F. P. Hassani, A. Hara, M. Momayez

To be competitive on the international market, the Canadian mining industry must reduce its costs, increase its productivity and maintain a high standard of safety. There is a great need today for improved methods that would allow the detection of geological structures in advance of mining to reduce dilution and the monitoring of underground structures to increase safety. This will facilitate planning for optimum exploitation of the mine and to increase production at lower costs. This paper discusses two examples of more efficient mine planning using new technologies such as Ground Probing Radar (GPR). In Kidd Creek mine, GPR technology was used at the 2500and 2600 levels to (1) monitor the stability of the sill pillar; (2) locate the presence of disseminated sulphide pockets in the sill pillar for extracting the mineral content; (3) monitor the stope backs and wall structures to evaluate the effect of on-time filling sequences; and (4)assess rockfill quality in terms of the presence of voids and fractures within the rockfilled areas. In the New Brunswick coal mine in Minto, GPR was used along with core log data to map and construct a 3D block of a section of the bench showing the relative position of different layers overlying the coal seam.

Jan 1, 1996

By D. C. Fraser

"Geophysical Engineering and Surveys Limited of the Keevil Mining Group have routinely conducted ground surveys with VLF-EM receivers for the past two years. Both Crone's Radem and Ronka's EM16 have been used.VLF-EM dip-angle data often yield complex patterns which require considerable study for a proper interpretation. A method was developed which allows field operators to transform the noncontourable dip angles into contourable data, producing conductor patterns which are immediately apparent to exploration personnel untrained in VLF-EM interpretation.VLF-EM contoured data generally peak very close to the top of a conductor, thereby allowing drill holes to be spotted accurately. However, the data generally should not be used alone to select drill targets because structures may be sufficiently conductive to yield strong anomalies. Thus, magnetic and/or vertical-loop EM correlations may be considered as necessary criteria for drilling.VLF-EM surveys can replace IP surveys in certain environments. For example, the Restigouche orebody in the Bathurst camp of New Brunswick yielded a VLF-EM anomaly as distinct as that obtained by IP, although the body did not respond to vertical-or horizontal-loop EM. However, the cupriferous breccia pipes of the Triba mine near Batchawana, Ontario yield strong IP anomalies but not VLF-EM anomalies, illustrating that disseminated ore targets should be sought with IP rather than with VLF-EM."

Jan 1, 1971

By J. Fixter, P. Prangnell, Z. Pinter, E. Eimer, B. Chehab

"High deposition rate Wire and Arc Additive Manufacture (WAAM) can provide benefits to the aerospace industry, including a reduction in lead time, reduced material waste and, through higher solidification rates, refinement of the as-built microstructure relative to a cast material. However, candidate 2xxx series high strength alloys for this process normally require a solution treatment, which is problematic for large near-net-shape components, and age hardening to achieve maximum mechanical properties. With each layer being subject to multiple thermal cycles, exploiting the thermal conditions in the WAAM process to avoid post-build solution treatment is therefore of interest. A solutionisation model has been developed for the WAAM process, based on diffusion controlled dissolution using DICTRA, which was validated through thermal simulations combined with 2D and 3D image analysis. The model has subsequently been used to simulate the solutionisation behavior during a typical WAAM thermal cycle and to explore what could theoretically be achieved by, for example, refining the starting microstructure.INTRODUCTION There is currently great interest in exploiting additive manufacturing (AM) in the aerospace sector due to several benefits it can potentially provide; including reduced material waste, shorter product lead times and greater design freedom (Herzog, Seyda, Wycisk, & Emmelmann, 2016). However, with aluminium alloys the material properties obtained are generally inferior to those of conventional high-strength wrought products; therefore more research is required to explore the potential for exploiting the unique process conditions in AM to improve the as-deposited microstructure. A range of AM techniques are now available (Debroy et al., 2018), which differ in terms of the feedstock type and power source and it is necessary to match the appropriate technology to a particular application. This generally requires a compromise between the build rate and shape resolution. Wire and plasma-arc additive manufacturing involves using an electric arc to melt wire onto a substrate, and fabricates a part by building up overlapping layers of deposited weld beads (Addison et al., 2015; Williams et al., 2015). The benefits of this process over other AM methods are the much higher deposition rates (e.g. kg’s/hour) achievable and lower capital equipment costs relative to powder bed techniques, which makes it suitable for large scale applications. However, limitations include a lower part complexity, lower solidification rates and a greater need for post-process machining (Frazier, 2014)."

Jan 1, 2018

By A. Allaire

The Goldex operation of Agnico-Eagle Mines (AEM) commenced operations in the spring of 2008. Following some months of initial operation, the grinding circuit capacity was under-performing according to the original design throughput. BBA Inc. (BBA) was commissioned, in February 2009, to study the different options and recommend the quickest and most cost-effective solution to increase the grinding circuit throughput rate. The mandate was to increase the throughput of the grinding circuit to beyond the original design of 7,000 tpd to 8,000 tpd or greater, while retaining the existing SAG and ball mills. The circuit was modelled using JKSimMet software to evaluate the different options, each with a number of different operating parameters. The option of secondary crushing of the SAG mill feed was retained. Comparison of the different options and simulation outcomes, design of the secondary crushing circuit, operating conditions, and initial adjustments in the design and operating results of the new grinding circuit are discussed in this paper.

Jan 1, 2012

By Rod Abbott

High Definition Scanning (laser scanning) is a proven technology that is accurate to within 6mm in 50m (¼? in 150?). It can capture in excess of one million 3D point measurements in an average 2 hour scan. It has numerous applications including brown-field retrofits, bridge measurement and analysis, verifying as-built conditions, and crime scene investigation. We most commonly use it for plant design to capture current site conditions, so as to prevent interferences and problems before construction begins. All vital information is captured in the first site visit, which limits the need for extra field trips.

Oct 1, 2010

By Enzo Angeles, Desmond Nanchengwa, Lee Julian, Julian Ruiseco

Since the early 1980s, surface hard-rock mining companies have searched for a blast movement model to enable grade control optimization efforts. Significant time and money were spent attempting to create blast simulations to aid post-blast grade control. Despite nearly 40 years of effort, practical blast movement models remained elusive until computing power reached levels that make real-time simulation possible. From the mid-1990s, mines have been creating in-situ grade control polygons and translating the polygon nodes horizontally to account for blast movement. In many cases, objects are placed in the blast volume and located post-blast to provide local vectors for these node translations. This method was always a compromise between practicality (2D) and reality (3D), but it was the only viable solution that matched the needs of operations. This study considers 21 blasts and evaluates the incremental value achieved by new processes unlocked through 3D modelling, while investigating challenges, limitations, and opportunities for each method.

Jan 1, 2023

By P. Turcotte, E. Karampinos

"Construction of underground excavations in squeezing ground conditions faces several technical challenges that can result in delays in production and high costs due to rehabilitation. A review of the behaviour of drifts under squeezing ground conditions was undertaken at the LaRonde mine. In particular it focused on implemented strategies to control the observed large deformations. The mine experiences a large range of squeezing ground conditions, mostly driven by the presence of foliation and high stresses. This results in large deformations over one meter in radius. A comprehensive ground control strategy has been implemented with the aim to manage, rather than arresting drift closure. The evolution and effectiveness of the employed support strategy are discussed based on documented field observations. In complement to the field implementation numerical models are used to provide further insight on the observed squeezing conditions.INTRODUCTIONThe development of underground excavations under squeezing ground conditions is usually associated with excessive rehabilitation and significant failure of ground support due to large deformations. Cost research case studies have concentrated on squeezing ground conditions in tunnelling. An overview of the methods used for the identification and quantification of squeezing and the numerical methods for the simulation of these conditions in tunnelling has been provided by Barla (2002). Numerous support systems that can manage ground deformation are available for civil engineering tunnelling. Nevertheless, the use of these systems in mining would result in high support cost and production delays. Mining operations have higher development rates and shorter service life. This study focuses on the behaviour of underground excavations under squeezing ground conditions in hard rock mining.In a mining context, the magnitude of deformation is usually higher than in civil engineering tunnelling as there is a higher tolerance for operation purposes. Potvin and Hadjigeorgiou (2008) noted that in mining, squeezing is encountered when the total displacement of an excavation reaches at least tens of centimeters over the life expectancy of a supported drive and is associated with considerable damage to the ground support."

Jan 1, 2015

By F. Ajersch, A. R. Hekmat

Apparent viscosities of hypo-eutectic (Al-7% Al) and hyper-eutectic (Al-35% Si) binary alloys were measured in the semi-solid state using a Couette type viscometer at variable shear rates. Analysis of the microstructural evolution demonstrates the differences in the rate and degree of attrition of the primary phase particles which are characteristic of the thixotropic nature of the semi-solid alloy. It was observed that the Si primary phase in the hyper-eutectic alloy is much more difficult to fragment than the dendritic a-Al phase in the hypo-eutectic alloy. For the case of the a-Al, the dendritic structure is broken down by attrition and fracture of the dendrite arms whereas the fracture of the Si hexagonal crystals in the hypereutectic alloy occurs along the {100} and {110} cleavage planes. Results are presented for fixed solid fractions of the primary phase at isotherm condition for each type of alloy.

Jan 1, 2006

By J. Awmack, M. A. Tomlinson, P. J. Lind

"Peñasquito is a complex polymetallic deposit containing gold, silver, lead, zinc, and copper and is one of the largest producers of gold in Mexico. Mining activity is currently transitioning to a second open pit, Chile Colorado, which will be mined concurrently with the existing open pit, Peñasco. The ore bodies are located within diatreme pipes and into the surrounding sediment formation. In the coming years, mining will be carried out in more sedimentary zones, which are significantly higher in organic carbon content. Organic carbon in the feed influences both flotation and leaching operations. Several changes are being implemented to the Peñasquito flowsheet to mitigate the effects of increased organic carbon in the plant feed. These include the use of alternate reagent schemes, construction of a carbon pre-flotation circuit, implementation of a pre-leach flotation circuit ahead of pyrite leach, and evaluation of a tertiary process for separation of carbon and precious metal minerals.INTRODUCTION Goldcorp’s Peñasquito operation is located in the Mexican state of Zacatecas, approximately 200 km from the city of Zacatecas in the Mazapil municipality (Figure 1). Peñasquito has been in operation since 2009, with mining carried out by open-pit methods. Oxide ore has been processed in a heap leach facility and sulfide ore is treated in the sulfide processing plant. The processing capacity of the sulfide plant is 130,000 tonnes of ore per day and in 2016 production amounted to 465,000 ounces of gold, 17.6 million ounces of silver, 109 million lb of contained lead in lead concentrate, and 263 million lb of contained zinc in zinc concentrate (Goldcorp Inc., 2017). To recover more of the contained gold and silver and to mitigate the impact of increasing organic carbon content in the ore, a number of significant changes are being made to the operation."

Jan 1, 2018

By D. Berkley

Off-gas systems often become the limiting factor in production increase and environmental projects. Any upgrade or new off-gas project needs to address control instability issues, instabilities that can result in safety hazards, significant loss of system capacity and/or emissions to the environment [1]. In addition, the design engineer must optimize system configuration and equipment size for the new operating conditions, to have a technically feasible and economically viable project. Dynamic simulations can be used for addressing both the control stability and the design optimization issues. This paper illustrates how the dynamic simulation of transient processes and of their control system can be used in "real life" situations for these purposes, presenting the example of an electric furnace off-gas system design.

Jan 1, 2005