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By A Krishnan, C Garcia, I Luna-Berbesi

The discovery and exploration of deposits are progressively shifting to extremely remote regions and greater depths. As a result, exploration costs and the economic risk of a bad investment increase. Current megatrends in the exploration and mining sector indicate a growing demand for the implementation of automation, digitalisation, and machine learning techniques. The implementation of a multi-sensor-based core logging device (DMT, 2024) was done on 400 m of drill cores to optimise interdisciplinary processes in terms of time and quality, by using interlinked and consistent data in real-time, to obtain reliable predictions that support and speed up decision-making. The results are consistent with the laboratory data previously obtained by the mining company, highlighting the benefits of introducing ANCORELOG into their core logging procedures.

Sep 1, 2024

The Electricity Generating Authority of Thailand (EGAT) Mae Moh coal mine is an open-cut coal mine in Thailand that produces about 16 Mt of lignite annually to generate 2400 MW of electricity. The surface mine pit covers is 4 km by 7 km with mining depths ranging up to 260 m. A large pit slope is formed with the progression of the mining operation. However, massive slides in the pit slope occur often due to the existence weak planes such as faults and bedding, and the weak mechanical properties of the rocks. Hence, 200 m to 300 m boundaries of rock block including coal seams are left in front of faults in order to prevent slides and maintain the stability of the pit slope. As a result, there are significant coal reserves beneath the abandoned area along the pit slope. Moreover, the mined coal seams are very thick and their thickness range from 15 to 30 m.This paper discusses the application of multi-slicing highwall mining system with stowing to this very thick coal seam left around large pit slopes by means of numerical analysis.

Dec 6, 2010

By G. Danko

MULTIFLUX, a new thermal, hydrologic, and airflow model and software is being developed to solve the flow of heat, moisture, and air in and around an underground opening. MULTIFLUX couples two distinct domains that are solved separately first and re-coupled as an iterative task: (1) the rockmass, and (2) the airway. The airway is solved with a lumped-parameter Computational Fluid Dynamic (CFD) module which is an embedded part of the MULTIFLUX code. The CFD model includes convection, conduction, and radiation for heat, as well as convection and diffusion for moisture transport in an air-filled opening. The CFD model also solves for the airflow field. The surrounding rockmass model may be from any analytical solution, or from a complex thermal-hydrologic numerical model such as NUFT or TOUGH2. The rockmass model is interfaced to MULTIFLUX using a novel technique called Numerical Transport Code Functionalization (NTCF). The method provides fast convergence on a personal computer platform. The paper reports the results of MULTIFLUX simulations for a mine drift, comparing calculations with a known mine climate software, CLIMSIM, and with measured data. Through this validation example, the performance of MULTIFLUX is demonstrated. The results show excellent agreement due to the use of realistic modeling assumptions and boundary conditions.

Jan 1, 2009

By Shuvranshu K. Rout, Anup K. Mandal, Biswajit Das, Manos De

"To adopt new technology advancement in Steel Plant, there is a requirement of shifting of operation process from Coke Wet Quenching (CWQ) to Coke Dry Quenching (CDQ). New CDQ chamber foundation with deep basement and underground conveyor tunnel are to be constructed in an operating plant where heavy foundations and structures are located in close proximity. Furthermore, the existing CWQ system will be in operation during new underground construction and erection. Challenges to deep excavation of tunnel and chamber foundation consist of non-uniform ground condition, prevent washing out of soil from bottom of existing foundations, stability of existing nearby structures, presence of large number of underground utilities, ensuring safe underground workplace to construction resources engaged in new construction work along with project schedule and budget constraints. A combination methods involving use of soil nailing, soil grouting, contiguous bored pile and micro pile had been adopted for protection of excavation sides as well as existing structures. Each side of excavation in different stretches were analysed during design as well as construction stages. The use of combination of all techniques in a single brown field project in context of the nature of site constraints and safety issues made this a unique project.INTRODUCTIONSteel Industry is one of the backbones of industrial growth of any developing country like India. Due to increasing land prices most of the steel plants in India are expanding within their existing plant facilities. In addition to that, there is demand of adoption of new technology for future expansion projects to set new benchmarks with global standards.The property owner had earlier installed a Coke Wet Quenching (CWQ) for their Coke Plant. Now, there is a requirement from process department to proceed with Coke Dry Quenching (CDQ). To facilitate the CDQ within the existing CWQ which will be in operation is the main challenge for the property owner. The second challenge is the limited space for underground construction and subsequent equipment erection within the stipulated time frame.From a geotechnical prospective, the project team had uncertainty and reservations in their mind about the construction methodology. Therefore, the role of three “C”: ‘Consultant’-‘Client’- ‘Contractor’ and their combining brainstorming is essential to freeze a working plan for achieving the goal. In this paper, only the excavation support systems for underground foundation structures have been highlighted in the context of solving geotechnical problems."

Jan 1, 2017

By Pierre Pelletier, Julie Fournier, Gianni Bartolacci, Yves Breau, Dominique Girard, Ahmed Bouajila, Carl Duchesne

"The development of on-stream analyzers (OSA), such as those based on X-ray fluorescence (XRF), has been key to improve metallurgical performance of flotation processes. However, since these analyzers are shared between several streams, they typically provide grade measurements every about 10-15 minutes. In general, this frequency is too long compared to process dynamics and so, implementing an efficient feedback control strategy based on OSA can be difficult. In addition, due to the limited capacity of OSA systems, several important intermediate streams are not analysed, but could provide relevant information about the state of a flotation circuit.To overcome this problem, vision systems have been developed in the past to predict concentrate grade based on froth color – this could be very useful to control flotation performance between OSA measurements. However, applications reported in the literature typically use univariate summary statistics of the full red, blue, and green color distribution of froth images, while RGB images are truly multivariate. Although, in some cases, grade prediction was achieved with reasonable accuracy, one may, by using only summary statistics, miss important information about the state of the flotation process.This paper investigates the application of Multivariate Image Analysis (MIA) concepts to flotation froth images. These techniques are based on multivariate statistical methods such as PCA and PLS, which have the ability to analyze large databases (such as digital images) and summarize the relevant information content of the data into a small number of latent variables, capturing the most important features of the images for concentrate grade prediction. The potential of application of these methods in the mineral processing industry is illustrated using a few industrial case studies."

Jan 1, 2003

By Frank A. Stephens

The process of converting iron ore (principally Fe,03 or Fe30,) into iron carbide (Fe,C) to be used as feedstock for steel-making yields complex mixtures of several Fe-containing compounds as a function of processing conditions. In addition to the above compounds (hematite, magnetite and cementite), the mixtures typically contain wustite (FeO) and metallic iron(Fe). Mossbauer spectroscopy has been developed into aquantitative analytical method for monitoring the degree of conversion to carbide from samples periodically extracted from a fluidized bed reactor type of pilot plant. Calibration of absolute quantities of the above five compounds is based on standards prepared from known mixtures of the high purity individual phases. The PC-based spectrometer allows fitting of the well-known spectral components of each of the five phases, the resulting spectral areas then being compared with the calibration curves via PC software to yield the weight fraction of each. Emphasis has been placed on standardizing and simplifying the analysis procedure for routine use in an industrial environment.

Jan 1, 1993

By I. W. van der Merwe

Recently, a new kind of filtration has emerged, namely nano-filtration (NF). It is a membrane-based process which exhibits totally unique separation characteristics for dissolved salts as well as for many non-charged species. By exploiting the particular separation characteristics of this new membrane type, many unique and novel separations have been made possible. The basis for separation by nanofiltration is the negative surface charge of the membrane. This results in rejection of multivalent anions, whilst associated cations are also rejected to maintain electro-neutrality. This peculiar property enables separation of dissolved ions such as sulphate and copper from acid, whilst the acid may be purified for reuse. This paper aims at providing an overview of the principles of nanofiltration, illustrated by particular examples.

Jan 1, 1998

By Pesic. Batric

A novel chitosan-pyridoxal-epichlorohydrin was synthesized and evaluated in our laboratories. The evaluation was achieved by performing kinetic and equilibrium studies of copper sorption. The parameters examined were pH, temperature, concentration of copper, particle size and selectivity of copper sorption against iron, zinc, cadmium and cobalt. It was found that pH was the most important parameter, and sorption of copper increased with pH increase in the range pH 2.5-6.0. The low activation energy of the sorption reaction, 1 1.13 kJ/mole (2.66 Kcal/mole), showed that temperature was not an important parameter. The synthesized chitosan was selective against iron, zinc, cadmium and cobalt. The selectivity with respect to last three metals was achieved by the kinetic difference of sorption, as sorption of copper was much faster than for other metals. Iron (Fe2+) does not adsorb on chitosan. The mechanism governing the sorption of copper is intraparticle diffusion. This finding was supported by the dependance of copper sorption on the square root of time, the low activation energy, and the fit of experimental data in the diffusion through the product layer equation.

Jan 1, 1994

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

Sep 13, 2010

By C. H. Bucknam

Net carbonate value (NCV) characterization methods for acid generation potential measurement originated from studies on the Carlin Trend during the 1990's and have been subsequently standardized through cooperation of the Acid Drainage Technology Initiative Metal Mining Sector and the American Society of Testing and Materials International. The paper describes the evolution and standardization of the NCV methods, the importance of mineralogy in interpreting the results and application of the methods to implementation of the Global Acid Rock Drainage (GARD) Guide.

Jan 1, 2011

By Sudhir Kumar Kashyap

In underground activities ground control is a challenging problem. It affects safety, production, and efficiency. As per statistics of accident data, ?fall of roof/sides? is one of the major causes of mine accidents. In many cases, our experiences and understanding of soil and rock behavior still fall short of being able to predict how the ground will behave. Presently, empirical approaches to design are widely used in estimating mine support parameters. Under these circumstances, expert judgment plays an important role, and such accidents can be obviated with accurate measurement and optimization of data and analysis using the neuro-fuzzy technique of artificial intelligence. Recently, a neuro-fuzzy hybrid approach has become one of the major areas of interest in engineering fields because it gets the benefits of neural networks as well as those of fuzzy logic systems, and it removes the individual disadvantages by combining them on the common features. Neural network and fuzzy logic technologies have common features, such as a distributed representation of knowledge, the ability to handle data with uncertainty and imprecision, etc., like in ground control. Fuzzy logic technique has tolerance for imprecision of data, while neural networks have tolerance for noisy data. In this paper we have focused an intelligent technique, i.e., neuro-fuzzy technique, to approximate the setting load given to the standing support (props) erected for the purpose of supporting freshly exposed roof during underground mining. We have used twelve input variables of rock parameters, and after having trained using a neural network with a sigmoidal function as an activation function, simulation was done to find the output parameter, i.e., the pre-load (setting load)to be applied on props. Outputs of the neural network were again fed to the fuzzy system together with the twelve parameters, incorporating five triangular membership functions for each parameter. Final optimum output was approximated using the MATLAB program, which was found to be satisfactory. Neuro-fuzzy technique has better performance over individual neural networks or fuzzy logic technique.

Jan 1, 2012

By Thoedtida Thipparat

The diaphragm walls and barrettes are very important to the constructions of multi-storeyed buildings, elevated expressways, subway railway stations, etc. Uncertainties particularly increase in accordance with the construction progress. Overcoming uncertainties influences the construction goals including achievement of time. This paper is aimed at proposing an uncertainty assessment and delay evaluation model to assess uncertainties and evaluate delay resulting from those uncertainties. Neurofuzzy systems (NFSs) for assessing uncertainties and evaluating delays are developed. Artificial neural networks (ANNs) have ability for learning from the past data and generalizing outputs for the next applications which are provided for fuzzy logic systems (FLSs). FLSs have ability for exploiting the tolerance of imprecision and uncertainty. FLSs provide the reasoning to the ANNs. Uncertainties affecting each operation were assessed and delays were evaluated by following steps of the proposed model. The uncertainty assessment and delay evaluation approach was applied to a diaphragm wall and barrette construction to demonstrate how to implement the proposed model. The results of the test case application were used for handling delay at all operations regarding the corresponding uncertainties.

Jan 1, 2006

By Alastair C. Torrance

"A brief review of the Australian mining industry is given followed by a more detailed treatment of a study of the influence of primer Size on explosive performance. This is based on a joint research programme conducted by BHP Central Research Laboratories and Dyno Wesfarmers Ltd and examined the effect of the size of cast primers on the run up and steady state detonation velocitiesof ammonium nitrate based explosives as a function of blasthole diameter. The field trials examined a numter of the Dynamo 'Westfarmers HDF series of primers in conjunction with ANFO, emulsion and watergel explosives. Results indicate that the iun up velocity of 187 mm diameter ANFO charges is negligible using cast primers as small as 150g. However, emulsion and watergel explosives did exhibit run up in both 187 and 3:1mm diameter blastholes, independent of the size of primer. This could last from 7 to 10 blashole diameters"

Jan 1, 1991

By J. Weinstein

New erosion, corrosion resistant metal, ceramic, and polymer composite technologies are being developed and marketed by Alanx Products L.P. for use in hydrocyclones, pumps, valves, and other applications in mining and minerals processing. This paper will present an overview of the ceramic/metal composite material system and properties developed, which include excellent erosion/ corrosion resistance. Wear data will be shown from a variety of laboratory tests in dry and wet conditions, in aqueous neutral and corrosive environments. Comparisons will be made with a variety of competitive materials currently used in the industries sited. Data will also be presented on field tests with pumps and hydrocyclones in hard rock mining and other abrasive/corrosive environments. Field data from North and South America, as well as Australian mining applications will be highlighted.

Jan 1, 1992

By J. Pizarro

Any organization that subjects its activities to a continuous improvement methodology, aiming to optimize their processes and services, must be able to adequately measure the results of the implemented changes to pursue better outcomes. This is no different for mining companies. When it comes to blasting, an accurate fragmentation analysis can correlate blast design and rock mass parameters to particle size distribution, enabling us to further analyze the correspondence of specific design patterns, applied to specific rock mass properties and the result in measured fragmentation indicators. Over time, many tools were developed for us to obtain PSD data, albeit each of them had their own shortcomings. The first ones to be developed involved photographing the muck pile including a scale object, uploading those photos to a PC, and using specialized software to analyze each one. As a result, analysts would get a PSD curve that served as reference for the performance of the blast. This method, which is still used, has major shortcomings. The most obvious one is that it is only able to capture a slice of the blast, which corresponds to the exposed section of the muck pile the analyst has access to, and even there its reach is limited to the areas that are safe for getting close enough for placing the scale, which are not many. Consequently, this is a very limited way to get a fragmentation performance assess for a blast. Currently, autonomous systems are capable of taking continuous pictures of the muck pile. Installed on a shovel, conveyor belt or crusher feed, these systems can take a continuous stream of pictures that are later analyzed automatically without the need of human intervention. These systems greatly increase the volume of data and, consequently, we have a PSD curve that is more representative of the blast performance. However, this technology still had issues when trying to sample front end loaders mining operations or getting results from underground blasting due to the inherent difficulties of these operations. New algorithms used for capturing and processing data for front end loaders can overcome the harsh environment of their operations and produce PSD data in high vibration environments and difficult mining angles. For underground mining, algorithms can be used to sample each truck exiting the mine, giving a reliable source of fragmentation analysis that can be traced back to their stope of origin. The development of this technology extends the existing system’s capabilities and helps us in our efforts to improve fragmentation results with each blast.

Jan 1, 2024

By X. Cui

Hydrocyclone is widely used in closed-circuit grinding process. However, in the first classification operation of coarse particles with high pulp density, the shortcomings of traditional cyclone are that the grinding cycle load is much high, the apex of cyclone is easily to be blocked and classification efficiency is less. Specifically, the problems of traditional cyclone used in grinding process are as follows: (1) Mill utilization factor is low and its handling capacity is small. (2) Coarse particles mixing in cyclone overflow affects the following separation process and fine particles mixing in underflow causes over-grinding, which affects the total recovery rate of valuable minerals. (3) High grinding cycle load leads to large amount of high-density slurry pumping, which causes high energy consumption and severe wear of cyclones, pipelines and pumps. The applications of new type pre-classification hydrocyclone with centrifugal volute in the first classification process of Iron Mine Mill are introduced in the paper. Pulp particles fed in the centrifugal volute were arranged in advance, so that coarse particles can be far away from the overflow pipe, which can reduce the short circuit current to avoid coarse particles entering overflow and improve classification efficiency and accuracy of cyclone. The strong points of the new cyclone in the coarse classification operation are as follows: (1) finer overflow and less fine particles mixing in underflow improves classification efficiency more than 10%; (2) lower ball mill load cycle improves ball capacity more than 10%;(3) grinding energy consumption reduces by more than 20% and cyclone feed pump reduces energy consumption by more than 12%. In short, new type pre-classification cyclone with centrifugal volute solves the problems of fine particles mixing in underflow, high grinding cycle load and less classification efficiency in the coarse classification operation. Therefore, it has broad application prospects in ferrous metal and non-ferrous metal ore dressing plant.

Sep 1, 2012

By Eric Keller, Jamal Rostami, Wenpeng Liu

"Roof and rib instability is an important issue in underground mining. To optimize ground support design, enhance ground stability, and reduce the possibility of roof or rib failure with minimal use of artificial ground support, it is essential to have an accurate understanding of ground conditions. This includes the location of voids, cracks, and discontinuities, as well as information about the different strata in the immediate roof. This paper briefly introduces ongoing research on void detection by using the roof bolter feed and rotation pressure. The goal of this project is to improve the sensitivity of detection programs to locate smaller joints and reduce the number of false alarms. This paper has presented a brief review of the testing procedures, data analysis, logic, and algorithms used for void detection. In addition, this paper has discussed the results of preliminary laboratory tests and statistical analysis of the data from these two drilling parameters used for void detection.INTRODUCTIONRoof falls are one of the most serious and frequent accidents in underground mining. Each year, personnel are injured or killed because of roof falls. Equipment can also be damaged when this occurs. According to Mine Safety and Health Administration statistics collected from 1999 to 2008, ground falls were the largest cause of fatal accidents in underground coal mining, causing around 40% of all fatalities (NIOSH, 2015a). Out of 8 to 10 fatalities and over 800 injuries are recorded each year in underground mines, there are nearly 2,000 reportable non-injury ground falls every year (NIOSH, 2015b).Certain features in the ground, such as voids, cracks, and discontinuities, are significant factors that cause roof support failures and roof fall accidents. Currently, several manufacturers provide smart roof bolters with limited capabilities for void detection. While successful in many instances, in laboratory experiments, the existing void detection systems have limited success in detecting void openings that are less than 1/8 inch This limited success was observed in testing concrete blocks with gaps in between, simulating a rock medium with voids. Detection programs have missed some voids, while, in some cases, they have shown false detection. These algorithms need to be more accurate in sensing voids to improve the capabilities of these programs."

Jan 1, 2016

Technically speaking, the concept of NDT sounds like the "magic bullet" when faced with a questionable drilled shaft. All the Contractor or Engineer needs to do is select an NDT method, apply it, understand the details and extent of the defect and determine whether it will impact the load carrying capacity of the shaft during it’s design life. Unfortunately, it is not that simple. NDT is a tool utilized to indirectly assess the condition of the completed drilled shaft. For the most effective interpretation, NDT data should be correlated with the subsurface information, visual observation, and detailed shaft installation records. The basis for acceptance or rejection of drilled shafts should not be solely based on NDT. The parties responsible for specifying, interpreting and using the NDT results must understand the capabilities and limitations of the method to be utilized, in conjunction with the relevant subsurface conditions of the site, before selecting and specifying a system and acting on the results. This is necessary so that an appropriate NDT method can be specified and contracted. In this manner the results and roles of the responsible parties can be clearly defined.

Jan 1, 2004

By Joseph Poplawski, Christian O’Keefe, Robert Maron

"Unique and difficult minerals processing measurement situations will be described and the application of passive array-based technology for performing these measurements will be illustrated. Examples of these situations include volume flow measurements in froth lines and flotation feed lines with entrained air, slurry lines with magnetite and other magnetic ore, slurry lines with abrasive or corrosive materials, high pressure lines, and slurry and non-slurry lines exhibiting scale buildup. Other situations include measurement of entrained air levels in pipes and in flotation columns. These measurements are achieved through CiDRA’s patented passive sonar array-based technology. This technology performs two independent measurements – flow rate and entrained air amounts. Two hardware implementations of this technology have resulted in a non-intrusive flow and entrained air meter which easily is installed on the outside of the pipe, and a submersible version for entrained air or gas holdup measurements which is used in flotation processes. Recent developments in extending this technology to solve other unique measurement problems such as valve movement confirmation will be covered.INTRODUCTIONThe minerals processing industry faces many unique and challenging process control conditions and environments. In terms of flow measurements, many of these situations are not being properly served by traditional flowmeters such as ultrasonic meters, magmeters, turbine meters, orifice plate meters, vortex flow meters, Coriolis flow meters, and venturi meters. A new class of flowmeters has been developed that solves these unique situations and flow measurement problems. This new class of flowmeter technology utilizes sonar-based processing algorithms and an array of passive sensors to measure not only flow, but also fluid composition. It does so accurately, reliably and without making contact with the fluid. These measurements are performed on practically any type of fluid within virtually any type of pipe.PRINCIPLE OF OPERATIONSonar array-based flowmeters are ideal for tracking and measuring the mean velocities of disturbances traveling in the axial direction of a pipe. These disturbances generally will convect with the flow, propagate in the pipe walls, or propagate in the fluid or slurry. First let us focus on the disturbances that convect with the flow. The disturbances that convect with the flow can be density variations, temperature variations or turbulent eddies. The overwhelming majority of industrial flows will have turbulent eddies convecting with the flow, thus providing an excellent means of measuring the flow rate as described below."

Jan 1, 2008

By Braden Lusk, Paul Sainato, Josh Calnan, Hiago Vasconcelos, Luis Felipe Marinho

"Blasting and rock fragmentation is one the most important unit operations in mining. Since itsintroduction into the mine production cycle, mining has become more efficient in mineral production(Hartman, 2002). Widely used with the main objective of breaking rock mass in smaller fragments to be loaded and hauled at a minimum cost, blasting is optimized when stemming materials properly confine drillholes charged with explosives. Halim Cevizci (2013) performed a stemming application using Gypsum plaster, a kind of material that exhibits solid-like behavior when it is dry. Based on his theory, the present article reports an experiment using another type of material that shows similar behavior, non-Newtonian fluids. The primary goal of this study is to measure the confinement effectiveness provided by a non-Newtonian mixture as the stemming component. The study also analyzes the explosives’ energy propagation throughout the rock mass relating to the stemming materials applied. Currently, mining literature recommends the application of dry granular materials in stemming columns, because of its inertial and high frictional effects (Hagan, 1973). However, the test verified that the mixture added to the stemming column was able to reduce energy and gas losses to the atmosphere, because of the liquid’s property of filling voids in the material. The solid-like behavior of the non-Newtonian mixture was investigated for its capability to improve borehole confinement, since the mixture reacts like a solid when under shear stress. The results were compared to those from sand and air stemming applications, configured in different arrangements. It was concluded that the non-Newtonian mixture yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock."

Jan 1, 2016