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By G. I. Mathieu

"An experimental study was carried out to evaluate the performance of column flotation versus conventional flotation for the recovery of molybdenite from a Newfoundland ore. The objective was to verify the claims made by the inventors of the flotation column, Messrs. Pierre Boutin and Remi Tremblay, that their apparatus reduces the entrainment of fine gangue and other mineral impurities in the froth product. The research included a factorially designed series of tests to determine satisfactory operating conditions of the column. These provided a basis for comparative flotation tests with column and Denver cells. In the course of the work, the action of a few depressants was studied. Results indicated greater selectivity in the column and reduced reagent consumption."

Jan 1, 1972

"The content of production reports has its origins in raw measurements taken in harsh production environments. The ensuing measurement/estimation errors always affect reproducibility such that, regardless of the fact that they are balanced through statistical data reconciliation, reported numbers are simply the most probable values of inferred probability distributions. This has important implications for how metal recoveries should be monitored and reported. Indeed, in a context where many process optimisation activities are based on small improvements in recovery, there should be no doubt that inadequate handling of measurement/estimation errors can easily exaggerate or mask actual changes in process performance. However, estimates of the reproducibility of reported metal recoveries are rarely reported to plant management. This situation persists despite the fact that a code compliant metal accounting system must inform management about business risks related to metal accounting. To this extent, this paper focuses on the continuous management of reproducibility level of metal recoveries in compliance with the best practices. Sensitivity analysis of primary and secondary metal accounting models is performed to show the resulting probability distributions for metal recoveries. Some guidelines are given for designing and managing metal accounting systems capable of achieving and sustaining predefined levels for the reproducibility of metal recoveries.INTRODUCTIONEach and every mineral processing plant produces daily, weekly and monthly production reports in which metal balances for payable and penalty elements are presented. While such production reports are usually consulted in offices, underlying raw measurements are taken in harsh production environments where mechanical vibrations, humidity, corrosion and dust, to name a few, disturb measurement procedures. It is thus no surprise that several authors (Francois-Bongarcon & Gy, 2002; Gaylard, Randolph, & Wortley, 2014; Holmes, 2010; Spangenberg & Minnitt, 2014) have reported pervasive issues related to mass/sampling measurements in the context of mineral processing."

Jan 1, 2016

By P. Blonde

Recent analysis has suggested that a balanced recovery profile can improve flotation bank performance. Test work was conducted to test the balanced profile concept at the Penhorwood talc mine near Timmins, Ontario, Canada. Plant trials were devised to determine how to control the recovery profile and the resultant impact on grade and recovery in a rougher bank of four cells. Accompanying gas dispersion measurements revealed a maintenance issue with one cell that was corrected. By manipulating air and frother addition it was possible to bring the bank closer to a balanced recovery profile and the down-the-bank grade/recovery improved. Plant production showed an increased talc grade at similar yield with the balanced profile. The results provide justification for a long term plant trial.

Aug 1, 2013

By T S. Cochrane

A variety of practical tests have been tried in the mining industry to determine the support properties of mine roof bolts. Such tests include torsion wrench readings, hammer blow tests and the use of plates with built-in tension indicators. This paper gives some details of pull tests with a hydraulic jack, as carried out in coal mines of western Canada. M A~Y criteria exist for establishing the efficiency of roof bolting, and the one adopted de-pends on the nature of the problem and on the individual leanings of the investigators. Consequently, sufficient studies have not been made from a common viewpoint or under similar geological and techno-logical conditions to compare these methods of evaluation. However, regardless of whether certain tests provide sufficient factual data to form a basis for theoretical research on bolting or not, many of these tests can and do provide a positive means of judging the suitability of chosen roof bolting techniques and equipment under definite geological conditions.

Jan 1, 1963

By E. L. Bruce

EUROPEAN Russia is mainly a great plain, the average elevation of which is only 600 feet above sea level and the maximum elevation less than 1,200 feet (Figure 1). The main divide between the Arctic ocean and the Black sea and Caspian sea is an indistinguishable topographic feature from which the Dneiper and Don rivers flow southward to the Black sea and the Volga river to the Caspian. The valleys of these rivers are but little below the general level (Figure 2). To the south, this great, rolling plain is broken by a low ridge of Precambrian gneisses and intrusive rocks. The Crimea is an upland from which the descent to the Black Sea coast is precipitous (Figure 3). The Ukrainian Soviet Socialist Republic occupies the southern part of the plain. It is the southwestern unit of the Union, bordered by Rumania and Poland on the west and by the Crimean Soviet Socialist Republic on the south.

Jan 1, 1938

By K. H. Poulsen, C. J. . Hodgson

Synvolcanic, layered gabbro-anorthosite sills at Rainy Lake, Northwestern Ontario, reflect a combination of igneous processes including fractional crystallization, wall rock assimilation and possibly liquid immiscibility. Chalcopyrite-pyrrhotite mineralization at the base of the Grassy Portage intrusion accumulated by crystallization of a sulphide liquid during cooling. Upward enrichment of Fe and Ti in this intrusion and also in the Bad Vermilion Lake anorthosite complex culminated with the crystallization of lenses of disseminated to massive magnetite+ apatite+ ilmenite+ rutile. Regional low to medium grade metamorphism and accompanying deformation resulted in recrystallization and local remobilization of ore minerals.

Jan 1, 1984

ABSTRACT The inevitable uncertainty in modelling spatial variables decreases as more data become available. This reduction depends on the properties of the variable being modelled. Spatially continuous variables show less uncertainty for a given spacing than erratic variables. A geostatistical simulation based approach is developed to quantify the relationship between uncertainty and data spacing. Reference realizations are sampled to condition additional realizations and quantify uncertainty. The procedure is automated, making it straightforward to consider sensitivity and different geological domains. A case study of the relationship between uncertainty and data spacing for net oil sands thickness data from northern Alberta is presented. _ KEYWORDS Simulation, Sampling,

Jan 1, 2013

By A. Manouchehrian, M. Cai

"Rockburst, which often occurs around underground openings in highly stressed hard rocks, is a sudden and violent unstable rock failure and is associated with energy release. Rockburst is very dangerous to workers and mining equipment, and it has been a major concern for deep underground construction and mining. Before excavation, rocks are loaded under a true-triaxial condition. Upon excavation, the rocks at the excavation boundaries are loaded in the maximum principal stress direction and unloaded in the minimum principal stress direction and this provides a necessary condition for unstable rock failure to occur. Understanding rock behavior under true-triaxial unloading condition is critical for developing measures to control unstable rock failure in underground construction.In this article, an explicit FEM tool is used to simulate rock behavior under true-triaxial unloading condition, with a focus on analyzing stable and unstable failure and the released energy during failure. Firstly, a uniaxial compression test was simulated. The results indicated that the adopted numerical tool was able to simulate stable and unstable failure by varying the Loading System Stiffness (LSS). In this research, Loading System Reaction Intensity (LSRI) was proposed as an indicator to identify stable and unstable failure. Secondly, unstable rock failure under true-triaxial unloading condition was simulated. A rock specimen was loaded in three directions; the lateral pressures (s3 and s2) were kept constant and the vertical stress (s1) was increased to a pre-defined stress. The specimen was suddenly unloaded in the minimum principal stress direction (s3) and loading in the s1 direction was continued until failure occurred. Different LSS values were considered and the results showed that the LSS influenced the failure mode; a soft loading system resulted in more violent failure and released more energy than that in a stiff loading system. The influence of specimen height to width ratio on rock failure was also investigated. It was found that failure in taller specimens was more violent than that in shorter specimens. Insights gained from the simulation are useful for better understanding of the influencing factors on the released kinetic energy during unstable rock failure and to find means to control rockburst damage in engineering practice."

Jan 1, 2015

By A Frydrychewicz, J. Mirza, J. Lipkowski

The objective of this work was to understand the mechanisms of action of additives, such as thiourea, that enhance gold leaching in thiosulfate solution. The leaching reaction and surface passivation were investigated using linear sweep voltammetry. Leaching currents were determined using analysis of current-potential curves and the mixed potential theory. The gold-electrolyte interface was further characterized with surface enhanced Raman spectroscopy. The results show how thiourea prevents formation of oxysulfur compounds, which passivate the gold surface. Other molecules such as 3- m ercaptopropionic acid and L-cysteine were also studied as possible additives to prevent passive layer formation.

Jan 1, 2011

By Mohamad Kharseh

There is general acceptance that climate change, which is the most important challenge facing humanity, is anthropogenic and attributed to fossil fuel consumption. Therefore, improving the performance of our existing energy systems and deploy more renewable energy resources is an urgent issue to be addressed. Geothermal refers to existing of heat energy in deep rock and sedimentary basins. This energy can be used to drive a power turbine to generate electricity. Traditionally, geothermal has been exploited in places with the plentiful hot water at relatively shallow depth. In the light of fact that ground temperature increases with the depth everywhere on the Earth, engineered geothermal systems (EGS) can be installed in any place to exploit the geothermal in generating energy. Unfortunately, the high exploration and drilling costs of boreholes is the main barrier to commerciality of EGS worldwide. In addition, there are technical problems associated with drilling big depth. In oil producing countries such problems can be addressed by utilizing whether active or abandoned oil or gas wells and, consequently, EGS can produce power at profit. The current study presents an analysis of a binary geothermal power generation system for commercial electricity generation in Qatar. For this purpose, two binary cycles are assumed the main difference between them is that the first one is air cooled while the other will be water cooled. The performance of the two cycles and the possibility of improvement has been shown. Economic analysis the power plant shows that the levelized costs of electricity is 3.6US¢/kWh and the pay-back time is less than 8 years.

Aug 1, 2013

By B. Westin, G. Voicu, C. Daoust

Orogenic gold deposits represent a major class of deposits that are found in various rock types of various ages. Those deposits show a strong structural control that usually complicates their interpretation at the regional and deposit scales. The Rosebel Gold district located in Surinam (South America) is hosted in a Paleoproterozoic greenstone belt of the Guiana Shield, and has been recently classified as one of those orogenic gold deposits. The gold district comprises eight distinct deposits located along three different structural trends and within different rock types. The mineralization is undefonned and shows a strong structural control characteristic of orogenic gold deposits. All the deposits of the Rosebel Gold district have been subject to a detailed structural analysis that has led to the elaboration of a new structural model for the whole gold district, which is now differing considerably from the previous models. This characterization had direct implications at three different scales. 1- While the older models were considering some areas of the property as gold-barren, the new structural model has led to recent exploration campaigns which have revealed positive results. 2- At the deposit scale, the comprehension of the various vein systems and of the folding of the host rocks has helped the establishment of optimized drilling campaigns. 3- At the mining scale, the comprehension of the architecture of the veins helps for the elaboration of optimized mining method. This study thus shows that the structural analysis of orogenic gold deposits is critical, and should be a priority for exploration and production in any mine.

Jan 1, 2011

By T. C. Crosby

"Grinding has a marked effect on concentrator recovery and operating cost, and improved operation through automatic control can enhance plant performance. The correct application of automatic control can only be accomplished after the basic process variables and their effect on mill operation have been defined. This paper develops a control system for a closed circuit grinding system. Typical control systems, such as those for feed, water flow, level and circulating load, are discussed. A method of determining controllability, using the calculated reaction curve technique, is outlined. Various successful automatic grinding control applications are discussed and future possibilities are outlined. Although this paper primarily deals with closed wet grinding• circuits, the principles involved can be readily applied to other processes."

Jan 1, 1967

Arguably the SMC Test® has become the most popular laboratory hardness test in the world with over 17,000 tests having been completed to date, covering over 650 different ore bodies. It is now routinely used in design, optimisation and orebody profiling projects. The test is unique in that from relatively small amounts of drill core it simultaneously provides parameters that are used in simulation modelling of AG/SAG and crushing circuits as well as work indices that are used in power-based equations for predicting the specific energies of AG/SAG/Crushing and HPGR circuits. The very large data base that has been accumulated has provided the opportunity to study the differences in variability from deposit to deposit. This paper describes and discusses the trends that have become apparent from the study of this data base. Recommendations for appropriate selection of sample numbers are also made which are based on these trends.

Jan 1, 2012

By K. C. Hendrick

The paper will review the significant developments in world copper over the past ten years and their impact on the Canadian industry. It will also examine the outlook for the future.

Jan 1, 1971

By Delio J-J Tortosa, Fred F. Langford

"The Cenex orebody occurs at the intersection of northwest and northeast-trending fault zones that formed during post-Hudsonian uplift. The ore is localized in breccia zones, along faults, and in veins and adjacent wallrocks. The host rocks are Tazin quartzo-fe/dspathic mylonites and ultramylonites and chloritesericite- quartz-graphite-feldspar mylonite schist. The uraniumbearing minerals are finely disseminated pitchblende and uraniferous titanate.The earliest mineralization may have been associated with /ate-stage retrograde metamorphism in the mylonite schist. The main stages of mineralization were associated with brecciation, hematization, carbonatization, and chloritization of the mylonites and ultramylonites. Uranium mineralization was clearly much later than any igneous or metamorphic activity associated with the Hudsonian orogeny.Late post-orogenic uplift, erosion, and deposition of the Martin continental clastics in fault basins were coeval with uranium mineralization. The deposit is consistent with a meteoric-hydrologic system constituting a source for orebearing fluids, hence the close spatial relationship of the uranium deposits in the Beaverlodge area with the basal unconformity of the Martin Group."

Jan 1, 1986

By M. S. King

"A simple method is proposed for determining the long-term deformation behaviour of evaporites. The theory developed can be tested by measuring the change in diameter as a function of time of a vertical mine shaft opposite evaporite strata. Ultimate shaft closures predicted by the theory agree well with those calculated with the very much more complex theory of Serata (1968), provided that sufficiently high octahedral shear strengths are used in the former.An analysis of measurements made in an isolated opening in a Saskatchewan potash mine shows that the octahedral shear strength of the surrounding potash and halite was approximately 500 psi several years after the opening was mined. This value is less than that deter-mined experimentally for halite by Serata. The same data indicate, furthermore, that the in-situ octahedral shear strength is decreasing slowly with time.The current controversy regarding the actual deformation of evaporites will only be resolved by the cooperation of potash producing companies in releasing data on the long-term deformation of their mine shafts."

Jan 1, 1971

By D. M. Xue, T. B. Li

"With the increase of human engineering activities, global climate change and active plate tectonics movement, the giant landslide frequently occurred in southwest China, which caused huge property and human losses. Besides, the potential landslides pose severely threaten to the construction and operation of airports, railways, highways and power stations etc. In order to provide accurate guidance for the landslide investigation, stability analysis and mitigation, the giant landslide is redefined according to landslide volume, depth of slip surface, complexity of landslide mechanisms, and degree of landslide mitigation difficulty, and classified with the typological classification approach based on the twofold attributes of landslide behavior including formation mechanisms and reactivation features. Finally, the threefold particularity of the giant landslide is also summarized, which enables a more effective landslide mitigation design.INTRODUCTIONWith the increase of anthropogenic activities, global climate change and active plate tectonics movement such as continual uplifting of Qinghai-Tibet plateau and strong earthquakes, the occurrence of giant landslides was in ascending trend in southwest China (Huang, 2009), which caused serious destruction, and greatly endangers such engineering construction from safety, time and economic aspects as airports, railways, highways, power stations, etc. Giant landslides have huge scale, complex formation/reactivation mechanisms and mechanical behavior. They may not be identified during the hazard investigation, but may be firstly initiated or reactivated due to the following engineering activities, heavy rainfall or strong earthquakes. Consequently, the landslide mitigation is inevitable and costly. However, it is difficult to control the deformation of giant landslide with lack of a correct understanding of genetic mechanisms (Marui, 2012; Zhang, 2000) and the excessive large sliding forces of the slide blocks calculated by the conventional limit equilibrium method. For instance, the failure of anchored pile wall for the No.102 giant ancient landslide (Zhu et al., 2012) and stabilization measures for the Sidi Rached viaduct landslide(Guemache et al., 2011); four rows of piles had not prevented the occurrence of the No.12 landslide in a high fill slope in the Panzhihua airport (Li et al., 2012)."

Jan 1, 2015

By Gordon E. Forward

Sustainable development in the mining and metallurgical industrial sectors can be implemented by two distinct groups: 1. The managers and operators of existing facilities ? working with industrial processes and systems that have been operating for many years, in some cases several decades 2. Those who are engineering and building new facilities or upgrades of existing plants. The focus of this paper is to look at approaches and tools available to bring sustainable development thinking and action to these two distinct areas. The paper will discuss: 1. The concept of working with existing facilities and processes to minimize waste and maximize product from a regional raw material/resource consumption perspective using By-product Synergy. The BPS concept has been carried out in Texas (TXI-Chaparral?s STAR Example), in Calgary, Alberta with Suncor assistance, in Montreal, Quebec with Noranda as project leader and currently in Ontario with Dofasco as industry champion. Successful outcomes are presented. 2. A new approach to designing greenfield facilities or upgrades to existing plants using a sustainable development review process. Undertaking the review early in every project can institutionalize the concept of discussing and implementing waste elimination, design for environment, eco-efficiency, risk minimization and community awareness and involvement in the future capital stock. The review process has been developed as an excellent tool for measuring and reporting on a corporation?s sustainable development progress. Examples of how this approach has been adopted in the mining and metallurgical industry, and the resultant outcomes are given.

May 1, 2002

By H. R. Banks

SHORTLY after the commencement of operations at the Sullivan concentrator, the use of a pilot table was instituted in order to present a visual control of various products by showing the amount of galena still present in the tailing from several stages of flotation. Among the products so treated, the final tailing was later included. It was sratifying to note that very little free galena was escaping, but a fine streak o a whitish mineral appeared at the concentrate zone. This mineral was identified as cassiterite. The amount was small and the newly recognized component in an already complex ore was considered primarily as of academic interest. However, the problem of recovering a usable metal was intriguing and, as opportunity presented itself in temporary lulls in research on Sullivan and other ores, the concentration of tin was a useful 'bit of knitting' to go on with. It was recognized from the start that the bulk of the mill tailing would have to be floated and the residue subjected to gravity treatment. Since one of the predominating features of Sullivan concentration operation has been the necessity of fine grinding, the problem of gravity concentration was thereby intensified. Several batch runs were made, and sufficient pulp was treated to produce about one ton of final tin concentrate assaying 67 percent tin. The overall recovery was under 30 percent and the estimated profit at full tonnage was only marginal. Testing was resumed several years later, when the price of tin again appeared attractive, in an attempt to develop a more compact plant with better recovery of tin. The weakness of the original plan of concentration was the large number of tables required to treat a feed so low in tin.

Jan 1, 1941

By Freislich. M., Y. Gordon

"In the changing global market scenario for raw materials for the steel industry, a number of novel iron- and steelmaking process technologies are being developed to provide the steel companies with economically-sustainable alternatives for iron- and steel-making. In addition, the steel industry is also focusing on reduction of energy consumption as well as green-house gas (GHG) emissions to address the crucial subject of climate change. In this context, it is important to assess these critical issues for the alternate iron- and steelmaking technologies that have been developed. This paper presents a comparative evaluation of energy-efficiency and GHG emissions for some selected iron- and steelmaking technologies that are being considered for implementation. In this work, Hatch’s G-CAP™ and En-MAP™ tools that were developed with the main objective of quantifying and qualifying the potential energy savings and CO2 abatement within the iron and steel industry, were employed in the evaluation conducted. INTRODUCTIONThe iron and steel industry continues to transform itself and evolve in the ever-changing global market place – the raw material scenario is constantly changing with respect to quality and quantity (availability), there is stiff competition in both global and local markets, and there is increasing pressure to address global climate change issues, especially since the steel industry is highly energy- and carbonintensive. There is growing importance of steel production in developing countries such as China and India – this means that the steel industry in these countries will play an important role in defining and shaping the future of the industry.Climate change is expected to present new risks to the steel industry with respect to ensuring a sustainable business. Legislators are proposing to limit GHG emission by placing an implicit price on CO2 emission - market-based “cap and trade”, carbon tax etc.. In this scenario, it is important for the steel companies to reduce exposure to climate-related risks and at the same time, find business opportunities within these risks. Thus, there is a need to strategically manage the climate change risks; the key steps to strategically manage climate change risks are presented in Table 1[1]."

Jan 1, 2012