Successful Mining Research Articles

An examination of house price movements in Queensland resource communities

ABSTRACT Successive mining “booms” have created wide-ranging, long-term socioeconomic impacts in many parts of Australia. Property markets were both directly and indirectly affected by the mining booms. Towns associated with mining activities experienced significant, rapid shifts in supply and demand levels for housing as well as changes to the amount and type of development occurring. The most recent “mining boom” in Queensland impacted on housing market dynamics, with impacts evident at all stages of the resource cycle. Housing markets were also indirectly affected by new actors and new drivers for buying property in these markets – as an investment. This paper aims to show that the “mining boom” was only one stage of a more complete cycle, and the impacts of this resource cycle on housing were particularly nuanced. Even in the short term, the importance of housing market stability-particularly measured through availability and affordability is important to the wellbeing of a town, and the underlying community. During the most recent cycle, housing markets in Queensland mining towns were uniquely affected.

Successful Mining of Important Data from Patient Archives with Natural Language Processing: Commentary on an article by Caroline P. Thirukumaran, MBBS, MHA, PhD, et al.: "Natural Language Processing for the Identification of Surgical Site Infections in Orthopaedics".

Successful Mining of Important Data from Patient Archives with Natural Language Processing: Commentary on an article by Caroline P. Thirukumaran, MBBS, MHA, PhD, et al.: "Natural Language Processing for the Identification of Surgical Site Infections in Orthopaedics".

Novel Segmented Roadside Plugging-Filling Mining Method and Overlying Rock Mechanical Mechanism Analyses

The no-pillar mining method is widely used in coal mining engineering because of its superiority in resolving mine pressure hazards and protecting natural resources. In view of the geological conditions of stable strata in a coal mine of the Shandong Coal Zone, a novel segmented roadside plugging-filling mining method is proposed by introducing the filling coefficient into roadside filling. The operation process is designed with a new grouting filling forming device. Based on the relationship between the theoretical deflection of a cantilever beam and geometric settlement and parallel settlement models, strength formulas applicable to the segmented roadside plugging-filling (SRPF) method at different migration stages are obtained, and the deformation formulas of a roadway toward a rock slab are solved by an elastic equivalent model. Further, the determination procedure of the filling mode under the mining method is clarified. The SRPF method was implemented on a test stope, and the test results indicated that the theoretical deformation produced by the SRPF method was small and can meet the mining requirements. Through on-site test monitoring, the deformation of surrounding rock was 0–160 mm and the filling body under the SRPF method could maintain its own strength and the stability of the surrounding rock. In addition, entire successful mining been completed in the working stope, which further proves the applicability of this method. The backfilling cost of the gob-side filling was reduced by approximately 50%, and the backfilling efficiency was improved in the mine. The description of the novel mining method may provide theoretical and practical guidance for coal mining in similar geological conditions.

Challenges and opportunities for a successful mining industry in the future.

EnglishModern models of sustainable economic growth are metal-intensive and will not be successful in the future unless a continuous supply of mineral-derived products is ensured. Despite this being logical, there is still a significant reluctance regarding mineral exploration and mining activities, often reflected in: (i) unfavourable public opinions; and (ii) absence of political measures or continuity of agendas that actually appreciate the way minerals are produced and the players directly or indirectly involved in this production. To succeed, the mining industry will have to (re)define its strategy and find innovative approaches to old problems and clearly demonstrate that mineral products can be efficiently delivered to support global development and assist suitable paths to welfare and quality of life, thus also providing real value to all concerned. In this study we give a concise review of the main challenges posed to the mining industry, and also indicate the most relevant opportunities and advance some proposals to constructively face the identified weaknesses and threats. The fundamental outcome is that the long-term balance between supply and demand of mineral products requires concerted actions on different fronts aiming: (i) the safeguarding of known resources; (ii) high-quality (scientifically and technologically driven) exploration surveys; (iii) improvements in mining and mineral transformation/ beneficiation; (iv) advances in consistent combinations of primary and secondary sources of raw materials, along with higher concerns on their judicious use; (v) effective and stable mining policies; and (vi) new insights on the role played by the mining industry through fruitful dialogues with society in general. EnglishLos modelos actuales de crecimiento economico sostenible resultan intensivos en el uso de metales, y no tendran exito en el futuro si no se asegura un suministro continuado de los productos derivados de los minerales. Aparte de esta evidencia, existe todavia un significativo rechazo relacionado con la exploracion mineral y las actividades mineras, a menudo reflejado en: (i) una opinion publica desfavorable; y (ii) la ausencia de medidas politicas o una continuidad en las agendas que valoren la manera en que se producen los minerales y a los actores directa o indirectamente envueltos en esta produccion. Para tener exito, la industria minera debera (re)definir su estrategia y encontrar acercamientos innovadores a los antiguos problemas, demostrando claramente que los productos minerales pueden ser suministrados eficientemente para mantener del desarrollo global y proporcionar rutas adecuadas al bienestar y la calidad de vida, proporcionando a su vez un valor real a todos los interesados. En este trabajo se realizara una revision concisa de los principales desafios que se encuentra la industria minera, senalando tambien las oportunidades mas relevantes y avanzando algunas propuestas para afrontar de manera constructiva las debilidades y amenazas identificadas. El resultado principal es que el equilibrio en el largo plazo, entre suministro y demanda de productos minerales, requiere acciones concertadas en diferentes frentes apuntando a: (i) la salvaguarda de los recursos conocidos; (ii) estudios geologicos de alta calidad (dirigidos cientifica y tecnologicamente); (iii) mejoras en mineria y transformacion/beneficio; (iv) avances en la combinacion de materias primas de origen primario y secundario, asi como una mayor preocupacion en su empleo; (v) una politica minera efectiva y estable; y (vi) una nueva percepcion del papel jugado por la industria minera mediante un dialogo fructifero con la sociedad en general.

Mining Pool Manipulation in Blockchain Network Over Evolutionary Block Withholding Attack

In the current blockchain network, many participants rationally migrate the pool to receive a better compensation according to their contribution in situations where the pools they engage encounter undesirable attacks. The Nash equilibria of attacked pool has been widely analyzed, but the analysis of practical methodology for obtaining it is still inadequate. In this paper, we propose an evolutionary game theoretic analysis of Proof-of-Work (PoW) based blockchain network in order to investigate the mining pool dynamics affected by malicious infiltrators and the feasibility of autonomous migration among individual miners. We formulate a revenue model for mining pools which are implicitly allowed to launch a block withholding attack. Under our mining game, we analyze the evolutionary stability of Nash equilibrium with replicator dynamics, which can explain the population change with time between participated pools. Further, we explore the statistical approximation of successful mining events to show the necessity of artificial manipulation for migrating. Finally, we construct a better response learning based on the required block size which can lead to our evolutionarily stable strategy (ESS) with numerical results that support our theoretical discoveries.

Soil properties and earthworm populations associated with bauxite residue rehabilitation strategies.

It is recognised that the establishment and function of soil biota is critical for successful mine residue rehabilitation. Bauxite residues are alkaline, saline and sodic and, whilst methods for establishing vegetation are well studied, little is known about key soil fauna such as earthworms. At a bauxite residue disposal area in Ireland, a 12-year-old rehabilitated residue was examined for evidence of earthworm populations. Five species of earthworm, dominated by Allolobophora chlorotica, were recorded in the rehabilitated residue representing the endogeic, epigeic and epi-anecic ecological groups. To further understand the potential for rehabilitated residues to support earthworm communities, a series of exposure tests was conducted. Whilst unamended residues (pH 10.2, EC 0.629mScm-1, ESP 54) was hostile to A. chlorotica survival, 100% survival was observed after 90days for gypsum and organic-amended residue at salinity of up to 2.9mScm-1, possibly due to calcium becoming the dominant cation. Survival of earthworms at salinities higher than anticipated tolerance levels suggests that specific ion dominance plays a role in earthworm survival in saline soils. Percent mass change was negatively correlated with pH, EC and sodium content of the residues. Residue from the 12-year-old site also supported the anecic species Aporrectodea longa over 100days. Percent mass change in residue samples retrieved from the 12-year-old site was significantly greater (p< 0.05) to that observed for a control soil. Capability of the rehabilitated residue to support earthworm populations indicates the development of a functioning soil system in rehabilitated residues.

An Informal Assessment of Twenty-First-Century Skills Developed Through Hidden Curriculum in Theatre Studies

Arguably more than any previous generation, students graduating from university programs in the twenty-first century need a comprehensive repertoire of essential skills for their rapidly evolving world. Undergraduate theatre training offers a wide range of those skills. In response to Glen Nichols’s prompt for the CATR panel discussions, I conducted an informal assessment of skills that are generated in Canadian theatre programs (2017) based on an available 1994 rubric for “Arts Education Standards and Twenty-First Century Skills.” 1 Analytical reasoning, information literacy, invention, self-direction, collaboration, and technological integration are examples of the competencies developed through effective undergraduate theatre studies programs; however, they are often the “hidden curriculum” (Jackson) little recognized by theatre educators and university administrators. There are limiting factors in the successful mining of the hidden curriculum for the benefit of our students including a lack of adequate teacher training for existing and incoming faculty (Pagen 223). Notwithstanding these factors, undergraduate theatre programs can provide a forum for the development of necessary skills for the twenty-first-century student.

Understanding the Weathering Process of Antimony Minerals: Case Study Sb-Mine Sulzburg, Black Forest, Germany

Concerns about heavy metal and metalloid contamination from mine dumps is one of the most intensively discussed issues in society, politics, and academia, because of the levels of pollution, and its toxic properties. During the Middle Ages the Black Forest was one of the most successful mining areas in Southwestern Germany. Historical records show that Sulzburg was a mining town in the Black Forest since the 10th century, but was abandoned in the 19th century. Nowadays this town is considered as an important recreation area in the country. Therefore, soil and water quality and any contamination are of great concern. The purpose of this research was to understand the weathering process and environmental impact of heavy metals and metalloids from the old antimony (Sb) mine sites in Sulzburg. In this study, we examined the mineralogy and whole-rock chemistry and per-formed soil sequential extraction and water chemical analysis around mine sites. The results show that the Sb deposits in Sulzburg contain mixtures of antimony-lead-bearing sulfides and sulfosalts in hydrothermal quartz veins. The primary ore stibnite (Sb2S3) and boulangerite (Pb5Sb4S11) occur associated with pyrite, arsenopyrite, and sphalerite. The whole-rock chemistry of Sb-Mine Sulzburg is characterized by considerable Sb2O3 (4-25 %) and PbO contents (2-7 %). This agrees with the che-mical composition of Sb minerals. Based on soil sequential extraction, toxic elements (Sb, Pb, As) mostly remain in the residual fraction. Comparing the water analysis at and around Sb-mine Sulzburg, Sb concentrations are lower than those of As and Pb for all water samples. This is possible due to the strong affinity of Sb to Fe-oxides-hydroxides and amorphous material and a lower mobi-lity, from the source into water. Based on these findings, we argue that sources of toxic elements and weathering process in Sulzburg are important from the ecotoxicity perspective. Changes in oxidizing or reducing conditions can lead to release and mobilization of Sb, As, and Pb into the environment.

A Hybrid Approach for Feature Subset Selection using Ant Colony Optimization and Multi-Classifier Ensemble

An active area of research in data mining and machine learning is dimensionality reduction. Feature subset selection is an effective technique for dimensionality reduction and an essential step in successful data mining applications. It reduces the number of features, removes irrelevant, redundant, or noisy features, and enhances the predictive capability of the classifier. It provides fast and cost-effective predictors and leading to better model comprehensibility. In this paper, we proposed a hybrid approach for feature subset selection. It is a filter based method in which a classifier ensemble is coupled with Ant colony optimization algorithm to enhance the predictive accuracy of filters. Extensive experimentation has been carried out on eleven data sets over four different classifiers. All of the data sets are available publically. We have compared our proposed method with numerous filter and wrapper based methods. Experimental results indicate that our method has remarkable ability to generate subsets with reduced number of features. Along with it, our proposed method attained higher classification accuracy.

Semantics of Social Media

The presented article is focused on the comprehensive study of the issues connected with text processing on social media. First and foremost, the standpoint of the so-called ordinary language philosophy is examined. It holds the view of the meaningfulness of words in sentences as being primarily determined by the ways in which they were put to use in the practical activity and the role they played in a broader context of the lifestyle. The contemporary lifestyle is inherent in social media with its virtual discourse which is determined not only by the words used but also by the relationships between the actors that generate the content. Second, the linguistic aspects of this issue are discussed. The modeling covering the structure of social media as well as users' texts are examined with regard to computational approaches to the broadening of the context concept in Frege's contextual principle. The examples of successful mining of such model both for traditional linguistic tasks and for the use in information filtering are provided. However, it is necessary to know how to broaden and narrow down the context. This aspect is examined by the example of clustering of the largest European social network VK

Gold on the Kaapvaal Craton, outside the Witwatersrand Basin, South Africa

Gold occurs in a variety of ancient geological environments in South Africa, the most well-known being the unique Witwatersrand Basin in the central part of the Kaapvaal Craton. Outside of the Witwatersrand Basin significant quantities of gold have been recovered from Archaean greenstone belts of the 3500 to 2700 Ma Kaapvaal Craton as well as from various occurrences in the 2600 to 2200 Ma Transvaal Supergroup. Very little gold has been found in younger formations. Archaean greenstone belts in South Africa are characterised by substantial sequences of ultramafic (komatiitic) volcanic rocks generally overlain by mafic volcanic successions which, in turn, are overlain in some cases by greywacke-shale sequences and younger arenaceous lithologies. Highly sheared and carbonate altered ultramafic zones, together with the immediately surrounding country rock, host some of the most important gold deposits on the Kaapvaal Craton. In the northern part of the Barberton Greenstone Belt, shearing tends to be most intense along the contact of the ultramafic schists of the Zwartkoppie Formation and the overlying greywacke-shales, the contact being marked by the presence of a chert “bar” or banded iron formation (BIF) horizon. Gold mineralisation occurs below, above and/or within the more competent and fractured chert/BIF marker horizon. The locus of gold mineralisation is typically controlled by the rheological characteristics of the wallrocks in the proximity of the shear systems, e.g. the ductile greywacke-shale strata are tightly folded with sub-parallel mineralised shear zones, while competent arenaceous rocks have yielded in a brittle manner resulting in high-angle mineralised fractures. Extensive carbonate alteration in ultramafic rocks is often present along, and in the vicinity of, shear zones where potassium alteration results in a vivid green coloration due to the formation of fuchsite (Cr-mica) and where zones of silicification and quartz veining are closely associated with gold, arsenic and antimony mineralisation. Where mafic rocks act as more competent and fractured hosts to mineralisation, carbonate alteration results in the breakdown of ferromagnesian minerals and the liberation of considerable quantities of silica, manifested as silicification and as mineralised quartz veins. The breakdown of mafic minerals results in “bleaching” of the rocks as carbonate minerals replace ferromagnesian minerals, but may also result in the development of green, brown or black schists depending on the composition of the host rocks. One or more of the above alteration rock types and mineralisation styles is present in virtually all of the greenstone-hosted gold deposits of the Kaapvaal Craton. Wherever available, geochemical data is consistent with alteration fluids of relatively uniform composition but the style of the resultant mineralisation is ultimately dependent on the nature of the host rock. Greenstone gold deposits are irregularly distributed, both in terms of their size and distribution. Only about 1% of greenstone deposits can be regarded as successful mines, while the vast majority remain as showings. Geographically, these gold deposits are preferentially located along litho-structural features where both fluid flow and wallrock conditions were suitable for mineralisation. These criteria are restricted to major structural nodes, significant lineaments, or lithological units, with the result that the stronger mineralising systems tend to be concentrated in finite gold “camps” which host the larger deposits and numerous styles of mineralisation, e.g., the Sheba-Fairview Complex on the refolded arcuate Eureka and Ulundi synclines. Gold hosted in BIFs is a widespread association, but rarely economic except where the nature of the mineralisation allows for economic extraction, e.g., in the Kraaipan Greenstone Belt, where the volume of BIF is large enough to contain the mineralised fracture system. Gold in the Paleoproterozoic Transvaal Supergroup occurs in the lowermost Black Reef Formation quartzites as detrital accumulations in conglomerate channels, but more abundantly as epithermal veins in the dolomite of the overlying Malmani Subgroup and shale of the Pretoria Group as vertical cross-cutting veins and sub-horizontal reefs emplaced along parting planes. The quartz-carbonate-sulphide veins differ from Archaean ores in that gold rarely impregnates the wallrocks; they contain significant carbon which impedes gold recovery, and they contain silver, copper, arsenic, bismuth, lead and zinc in addition to gold.

Mining Human Activity Patterns From Smart Home Big Data for Health Care Applications

Nowadays, there is an ever-increasing migration of people to urban areas. Health care service is one of the most challenging aspects that is greatly affected by the vast influx of people to city centers. Consequently, cities around the world are investing heavily in digital transformation in an effort to provide healthier ecosystems for people. In such a transformation, millions of homes are being equipped with smart devices (e.g., smart meters, sensors, and so on), which generate massive volumes of fine-grained and indexical data that can be analyzed to support smart city services. In this paper, we propose a model that utilizes smart home big data as a means of learning and discovering human activity patterns for health care applications. We propose the use of frequent pattern mining, cluster analysis, and prediction to measure and analyze energy usage changes sparked by occupants’ behavior. Since people’s habits are mostly identified by everyday routines, discovering these routines allows us to recognize anomalous activities that may indicate people’s difficulties in taking care for themselves, such as not preparing food or not using a shower/bath. This paper addresses the need to analyze temporal energy consumption patterns at the appliance level, which is directly related to human activities. For the evaluation of the proposed mechanism, this paper uses the U.K. Domestic Appliance Level Electricity data set—time series data of power consumption collected from 2012 to 2015 with the time resolution of 6 s for five houses with 109 appliances from Southern England. The data from smart meters are recursively mined in the quantum/data slice of 24 h, and the results are maintained across successive mining exercises. The results of identifying human activity patterns from appliance usage are presented in detail in this paper along with the accuracy of short- and long-term predictions.

The potential for deep groundwater use by Acacia papyrocarpa (Western myall) in a water‐limited environment

AbstractKnowledge regarding the use of groundwater by plants has implications for successful mine rehabilitation and revegetation programs in water‐limited environments. In this study, we combined several approaches to investigate water sources used by Acacia papyrocarpa (Western myall) in the far west of South Australia, including stable isotopes, water potential, groundwater and soil chemistry, and root mapping techniques. Plant δ18O signatures and water potentials were compared against a range of possible sources: rainwater, surface soil water (≤1 m depth), and deep groundwater (&gt;20 m depth). Our aim was to determine whether groundwater contributed to the mix of waters used by A. papyrocarpa.Overall, we found that trees did not source surface soil water (≤1 m), and probably sourced deep soil water (i.e. &gt;1 m) rather than deep groundwater. Groundwater, however, could not be dismissed as a potential source, as root mapping showed tree roots were capable of reaching groundwater at depths &gt;20 m, and isotope results indicated a potential contribution by groundwater to tree water use. However, low osmotic potentials and/or high acidity levels were shown to pose likely barriers to groundwater uptake, at least at the time of sampling. We conclude that because groundwater salinity and acidity are spatially variable in this region, plants with extensive root systems may be able to utilize zones of groundwater with lower salinity and pH levels. Overall, this study contributes to our limited understanding of groundwater use by trees occurring in water‐limited environments where groundwater is extremely deep (&gt;20 m depth).

Development of a predictive model to determine the temporal variability in mine feed water quality towards informing and forecasting plant operating strategy – a South African coal mine water treatment plant case study

The feed water quality associated with mine water treatment is typically characterised by a dynamic variability resulting from the fact that the final feed water to the water treatment plant (WTP) can be an amalgamation of water streams emanating from a number of sources. Consequently, the ability to deal with the dynamic nature of the feed water quality towards successful and sustainable mine water treatment goes beyond a proactive approach and requires a systemic, predictive approach. This paper discusses the development of an unsteady state mass balance model on a surface dam located on a coal mine towards predicting the dynamic fluctuations in total dam volume and its total dissolved solids (TDS) concentration in the feed water to a NuWater 20 MLD mobile WTP, comprising chemical conditioning, ultrafiltration and reverse osmosis (RO). The unsteady state mass balance, incorporated water entering the dam via the opencast pits, underground compartments, seasonal rainfall and the RO brine return. Water leaving the dam comprised the feed water to the WTP, partial brine treatment, surface evaporation and seepage. Validation of the model using actual data over an 8-month period showed excellent results. The model showed that without water treatment, the dam would overflow in 218 days. Although the dam's volume could be sustained at the ideal volume by treating 14.2 MLD, its TDS would exceed the maximum environmental limit in 197 days. Consequently, the combination of a 13.2 MLD WTP with a 1 MLD brine treatment plant provided the optimal water treatment strategy to sustainably maintain the dam's TDS concentration and volume within acceptable limits over the 5-year investigation period. This paper demonstrates the importance of using a predictive methodology for forecasting feed water characteristics and as an early warning system for most water treatment systems that are subjected to dynamic conditions.

Analysis of Protein Microarray Data Using Data Mining

Latest progress in biology, medical science, bioinformatics, and biotechnology has become important and tremendous amounts of biodata that demands in-depth analysis. On the other hand, recent progress in data mining research has led to the development of numerous efficient and scalable methods for mining interesting patterns in large databases. This paper bridge the two fields, data mining and bioinformatics for successful mining of biological data. Microarrays constitute a new platform which allows the discovery and characterization of proteins.

Progressive Plant Extension Applied to the Soil Treatment Facility of the “Arge Ground Unit”, Particularly Enhancement of the Treatment Range and Optimization of the Product Flows: An Example for Successful Urban Mining

The wet-mechanical soil treatment plant (soil washing plant) of the consortium “Arge Ground Unit”, located at the industrial area Linz (Upper Austria), was extended progressively. Particular mineral processing techniques were applied for the enrichment of contaminants and a continuous optimization process was implemented, pertaining all material flows from coarse gravel fraction to filter cake. Considerable quality control improvement and cost reduction were achieved by optimizing the wet-mechanical soil treatment plant. Particularly the disintegration and pre-separation of low-density material from the contaminated input material, the efficiency of the process water cycle and the decontamination of the sand fraction 0/4 mm were improved significantly in regard to higher PAH-contaminated material from the high priority remediation site ‘Cookery Linz (O76)’. In addition, flotation tests were performed with contaminated sand and dewatered filter cake, which finally led to the final extension step of integrating a two-step froth floatation unit into the existing plant concept for the treatment of the highly-contaminated thickener sludge. Owing to the plant expansion, the CO2 reduction within the operation period of 2009–2015 was in a considerable range of 2,280 metric tons. The current status and insights gained are subject of this technical note.

Estimation of Mining Project Values Through Real Option Valuation Using a Combination of Hedging Strategy and a Mean Reversion Commodity Price

Cash flows generated from mining projects are typically highly volatile and significantly influenced by a number of exogenous factors including commodity price as one of the most influential uncertainties. In addition, mining projects are complex and many of their executed investment decisions are irreversible. Therefore, management needs to address this potential risk exposure before making an investment decision. Due to the deterioration and fluctuation of mineral commodity prices for a successful mining project acquisition or development, an important and appropriate investment strategy should include a hedging strategy for reducing potential losses suffered by a company. The discounted cash flow methods, which are commonly used to calculate mining project values, often fail to respond to this identified economic uncertainty and also to incorporate de-risking hedging strategies. Therefore, this study approximates the numerical value or value ranges of a mining project considering the combination of a mean reverting commodity price and hedging strategies using continuous time modeling. A novel time-dependent partial differential equation has been proposed using a continuous time, mean reverting model, and hedging strategy to approximate the mining project value. Application of a new real options valuation technique demonstrated its superiority by providing the advantage of mitigating financial losses and procuring financial gains. In this study, some key results are deferral option and expansion option enhanced the maximum values of the project which are, respectively, 2.51 % and 4.4 % compared to the base case. Furthermore, the country risk has a great impact on project values, as when we considered the country risk premium is zero in our model, the project value increases up to 0.97 %.

Particle swarm optimization approach for forecasting backbreak induced by bench blasting

One of the most challenging safety problems in open pit mines is backbreak during blasting operation, and its prediction is very important for a technically and economically successful mining operation. This paper presents application of particle swarm optimization (PSO) technique to estimate the backbreak induced by bench blasting, based on major controllable blasting parameters. Two forms of PSO models, linear and quadratic, are developed based on blasting data from Sungun copper mine, Iran. According to obtained results, both models can be used to predict the backbreak, but the comparison of two models, in terms of statistical performance indices, shows that the quadratic form provides better results than the linear form.

XRF Standardless Comparison of Mining Head and Tail Grades to Screen and Display Ore Processing Recoveries

Separation of target elements or minerals from their host rock or ore is essential to successful mining operation. The inevitable loss of a portion of the desired material that accompanies each step in the extraction process must be documented to develop the operational protocol. Superposition of the characteristic X-ray fluorescence spectra of head (crushed rock ore particles, pre-processing) and tail (post-processing particles) samples provides a direct visual comparison of relative peak sizes, and thereby the relative concentrations, of elements of interest. If the head and tail peaks are identical, none of the element was recovered in the extraction process. At the other extreme if the tail peak “flat lines”, i.e., there is no peak, there was 100% recovery of that element. Standardless visual comparison is valid if the same mass of identical starting material is incorporated into the head and tail sample analysis pucks, and XRF analytical conditions are identical. The considerable time and expense of acquiring and calibrating the standards associated with XRF analysis of 75 or more elements are avoided, a significant advantage during initial broad screening of an experimental extraction procedure. Full quantitation by XRF or an alternate technique can proceed at a later project stage, if desired. The approach retains and presents all features of the original data, thus eliminating questions about data quality, standards and their calibration, and data manipulation in processing from raw counts to concentrations in printout tables. This form of display is ideal for both the mining professional and such less technical groups as corporate staff, investors, regulators, and the public. Examples presented herein are for heap leaching; the protocol can be applied as well to any of the other traditional ore processing and beneficiation procedures, e.g., gravity concentration, magnetic and electrical separation, froth flotation, and ore sorting.

Integrating geological uncertainty in long-term open pit mine production planning by ant colony optimization

Meeting production targets in terms of ore quantity and quality is critical for a successful mining operation. In-situ grade uncertainty causes both deviations from production targets and general financial deficits. A new stochastic optimization algorithm based on ant colony optimization (ACO) approach is developed herein to integrate geological uncertainty described through a series of the simulated ore bodies. Two different strategies were developed based on a single predefined probability value (Prob) and multiple probability values(Probnt), respectively in order to improve the initial solutions that created by deterministic ACO procedure. Application at the Sungun copper mine in the northwest of Iran demonstrate the abilities of the stochastic approach to create a single schedule and control the risk of deviating from production targets over time and also increase the project value. A comparison between two strategies and traditional approach illustrates that the multiple probability strategy is able to produce better schedules, however, the single predefined probability is more practical in projects requiring of high flexibility degree.