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By Mike Dry, Mani Manimaran, Mykolas Gladkovas, Mariam Melashvili, Chris Fleming

Development of a new hydrometallurgical flowsheet requires quantitative description and optimisation of all chemical processes in each step in the process, as well as mass and energy balances across a fully integrated circuit incorporating all the unit operations. This paper covers steps leading to early modelling of a gold processing plant based on a bromine/bromide lixiviant. Research conducted at SGS Lakefield in collaboration with Albemarle provided the data that were used in the development of this model. A previous investigation in this series described the leaching behaviour of various mineral types in Stabilized Bromine reagent. This paper is concerned with the gold recovery operations associated with a conceptual bromine leaching process. The recovery of gold by different types of resin and activated carbon was studied, along with various methods of stripping the gold from the extractant. The circuit is closed by electrolysing the spent leach liquor to oxidize some of the contained bromide back to bromine that would allow recycling the regenerated leach solution back to the leach step in the process.

Jan 1, 2015

By L. Dorador

"In block caving projects, the rock mass fragmentation process plays a controlling role in the design and success of the operation. Poorly understood, however, is the secondary fragmentation that occurs as blocks of caved ore move through the draw column and interact with one another. The initial size of these blocks can be considerable, as can their strength and stiffness as the presence of non-persistent joints and veining will be variable. Intuitively, more planes of weakness within the blocks should facilitate early fragmentation, but this assumption could depend on additional factors such as contact type between adjacent blocks and loads imposed through varying heights of the draw column. This paper reports the findings from a laboratory investigation examining the role of block strength and planes of weakness on secondary fragmentation. Testing was carried out on small-scale concrete cubes of uniform size, with and without embedded planes of weakness. The results obtained demonstrate the significance of veining and other planes of weakness on secondary fragmentation under one-dimensional compression, and allow for the development and constraint of empirical guidelines.INTRODUCTIONThe fragmentation process during block caving involves the initial (primary) fragmentation of rock in the cave back through stress-induced fracturing, release and fall of individual blocks onto the broken ore muck pile. This is followed by secondary fragmentation involving splitting and rounding of blocks as they move downwards through the draw column towards the draw point. The degree of secondary fragmentation achieved involves many variables related to the mechanical properties of the rock blocks as well as different operational factors. With respect to the block properties, the presence of planes of weakness in the form of veining and non-persistent joints is a topic of special interest given the significant influence it potentially has on the overall fragmentation process. However, the inherent heterogeneity and variable size of individual blocks generated from the cave back makes it difficult to develop any empirical relationships relating secondary fragmentation to compressive loading based on insitu observations and mine data. More preferable would be to keep constant block parameters, such as shape (aspect ratio and angularity) and size, through controlled laboratory testing. This work presents an efficient technique to fabricate concrete cubes in order to keep constant different block properties. These are then tested under one-dimensional compressive loading. The objective of these tests is to emulate a tight packing condition of single blocks such as that which would occur when the air gap between the cave back and broken ore in the draw column is small. When the air gap is small, detached blocks are unable to fall and rotate but instead maintain a very tidy arrangement with minimal voids left between adjacent blocks."

Jan 1, 2015

By N. Erarslan, M. Ghamgosar

The size of rock fragments depends on the nature of the loading applied the strength of the minerals and the texture of the rock. Research in the literature demonstrates that there is a distinct difference in the rock fracturing process for static and cyclic loading. The tensile strength of brittle rocks is also one of the most significant parameters influencing the rock fracturing process and the propagation of micro-fractures on the crushing, blasting and cutting of rock. The Brazilian indirect tensile test, one of the methods approved by the International Society for Rock Mechanics (ISRM), has been used to determine rock fracture behaviour under different cyclic loading modes. In this study, the dimensions of Brisbane Tuff specimens have been selected according to the method outlined by the ISRM. The main aim of this study is to evaluate the effect of cyclic loading amplitude and frequency on the Fracture Process Zone (FPZ) at the micro-, meso- and macro-scales. The post-failure behaviour of the Brisbane Tuff specimens was obtained under cyclic loading with frequencies varied from 1 to 10 Hz. The amplitude was varied from 10% of Ultimate Tensile Strength (UTS) up to 80% UTS. Laboratory investigations of rock fragment size revealed that different loading frequencies and amplitudes produce different FPZ dimensions. Multivariate Analysis of Variance (MANOVA) results demonstrated that the FPZ dimension is relatively sensitive to the frequency change. Fragment size analysis showed that the FPZ is a consequence of the initiation, propagation and coalescence of micro-fractures and depends on the nature of the loading. Laboratory evidence showed that the FPZ dimension, for the cyclic tests performed on Brisbane tuff, is ranged from 0.07 to 20 mm. The achievement of this study highlights a key finding in the understanding of fracture patterns and propagation models in the FPZ under cyclic loading, which is the dominate mechanical action in the oscillator disc cutter (ODC).

Jan 1, 2015

By J R. Barber, B. E. Rogers, R. Fukuzawa

Mercury is sometimes present in non-ferrous ores including gold, zinc, copper and lead. The selection and use of appropriate mercury abatement technology is critical for preventing its release to the environment during ore processing and to protect workers from mercury exposure. This paper presents a general decision-making process for mercury abatement technology selection for major emission sources in the gold industry. Mercury abatement can be accomplished through making process changes and/or by adding a process step to an existing system (i.e. "end-of-pipe control"). Advantages and limitations of the technologies along with waste / by-product management options are discussed through case studies of current operating mercury abatement systems.

Jan 1, 2015

By Xiong Tong, Jiushuai Deng, Yingbo Mao, Lingyun Huang

Ammonium carbamate has been used as a reagent for the leaching of copper from the copper oxide ore found in the Honghe state, Yunnan province, China. In order to find the optimal conditions for the leaching of copper from this copper oxide ore,the effects of several processing parameters, including the concentration, time, temperature, particle size and stirring intensity have been investigated. The results of these optimization experiments showed that the leaching rate of copper reached up to 72.76% under the following conditions: liquid-to-solid ratio of 10:1, ammonium carbamate concentration of 2.5mol/L, leaching temperature of 45 °C, stirring speed of 300rpm, a reaction time of 1.5 h and 85% by weight thereof passes through a sieve having 0.074 mm.

Jan 1, 2015

By F. Baczek, S. S. Rocks, D. Chaiko, T. Walters

The atmospheric leaching of chalcopyrite concentrates using acidic ferric sulfate lixiviants is well known to suffer from slow leach kinetics and poor copper recoveries. A number of approaches have been proposed for improving both leach kinetics and recoveries in this system. Many of these, while effective, suffer from high CAPEX and/or OPEX. As many mine sites begin transitioning from heap leaching of copper oxides to processing of primary copper sulfides, cost-efficient leach processes that are compatible with existing SX/EW processes will be needed to maintain existing cathode production. To this end, FLSmidth is exploring process options and reactor technology for the hydrometallurgical processing of primary sulfides. One approach that appears to be highly effective at increasing copper recoveries takes advantage of the enhanced reactivity of transitory, surface-defect structures generated during particle fracture. Significant process efficiencies are gained by matching the rate of grinding to the rate of electrochemical leaching in Mechano-Chemical leach processes. The patent-pending FLSmidth® ROL process uses a Stirred Media Reactor (SMRt reactor) to achieve copper recoveries of 97+% in 6 hours or less. This approach overcomes many of the surface passivation problems that have hindered other atmospheric leach processes. New insights to leach mechanisms are presented.

Jan 1, 2015

By X. S. Fan, T. R. Feng, D. Chen

To meet the flotation process requirements, the large-scale flotation cell must be designed for sufficient pulp mixing, reasonable air dispersion and solid suspension, which is very difficult to design for super large-scale flotation cell. Hence, the flotation cell scale-up and optimization for a short period is a challenge for super large-scale flotation cell design. Computational fluid dynamics simulation has been applied in flotation cell study, which is effective, timesaving and low cost in the study of the flow field distribution for super large-scale flotation cell. This paper demonstrates the flow field characteristics in the 600m3 flotation cell by CFD. The flotation cell model is meshed with hexahedral grid and the high mesh quality assures the computational precision. MRF model, namely a steady-state approximation, ensures that individual cell zones can be assigned different rotational speed. Euler-Euler approach is chosen for multiphase flow simulation to treat different phases as interpenetrating continua. Numerical simulation of single phase, two-phase and three-phase are investigated respectively. Results suggested that the flotation cell has the apparent upper and lower flow circulation. In condition of the impeller rotation, the air is dispersed reasonably. In addition, the solid phase volume concentration distribution in the cell has a little difference.

Jan 1, 2015

By J. L. Feng, F. Zhang, S. K. Hu

"Cracking is one of the most serious damages in tunnel linings, which is often observed by in-situ inspection to tunnel engineering. It is difficult to better characterise for the deformations from continua to discontinua by the traditional continuum mechanics due to emerging of crack initiation, crack propagation, and coalescence, at several scales. In this paper, the process of failure that was from micro damage to macro crack in concrete tunnel linings under experimental load conditions, was quantitatively simulated by the combined finite-discrete element method (FDEM). Comparison of the simulating results with that obtained by the full-scale test of concrete lining under different loading conditions in the literature was respectively good agreed and shows that such FDEM technique is appropriate to model the continuousdiscontinuous problems. The present study indicates that the FDEM technique could be benefit to quantitatively evaluate the stability and damage level of tunnel lining system. INTRODUCTIONMost damage to tunnel linings is caused during the construction phase, which can emerge in a form of single macro cracks or even large-scale spalling. The cause of such damage is mostly the occurrence of, either impermissibly large contact stresses resulting from high thrust loads combined with production and installation tolerances in the segments resulting in a geometrical lack of fit (Maidl et al., 2012; Transportation Research Board, Basic Research and Emerging Technologies Related to Concrete Committee, 2006), or unallowable tensile/shear stresses appearing in the tunnel linings under complicated loading conditions (Ansell, 2010). Such a macro failure phenomenon may also be regarded to as a result of growth, coalescence, initiation of microcracks in tunnel linings due to the complicated loading action, and even potentially lead to an instability or collapse of the local or entire tunnel system. Much work has been devoted to investigate for the characters of micro and macro cracks, the influence factors of damage patterns, the settlement of a tunnel, the width, length and density of lining cracks, especially from classifiedly and qualitatively (Wang, 2010; Huang et al., 2013). However, the safety evaluation of tunnel is definitely required to not only inspect in situ, but further also quantify computing and analyzing for tunnel lining systems, so as to provide a global viewpoint of process of the tunnel deformation, which aims to help for subsequent decisions, e.g. controlling traffic flow or immediately repairing task. Additionally, the design of lining thickness and its structural analysis that is mostly determined by previous experience and similar construction examples is also needed to be improved."

Jan 1, 2015

By G. L. Zhu, Y. F. Wu, H. Nagaumi

A novel eutectic-type alloy Al12Si-HTC with high thermal conductivity has been developed by strict chemical composition control and heat treatment. The thermal conductivity of the alloy is about 30 % higher than that of current commercial Al12Si alloy. The Al12Si-HTC alloy has a silicon content of 10~12 wt.%, which provides excellent castability. Trace element strontium or calcium is added to modify eutectic silicon, and contents of transition elements such as copper, manganese are controlled in a low level. By appropriate heat treatment, thermal conductivity of the castings increases by 7.5 % and finally reaches 172 W/(m·K). It is found that eutectic silicon modification which makes average particle size finer than 2µm plays a dominant role in improving thermal conductivity, as well as further spheroidization of eutectic silicon and reduction of lattice defects in a-Al microstructure in subsequent heat treatment process. The alloy is successfully applied to produce a certain communication enclosure with complex finned structure by die casting process in industrial scale. The results of numerical simulation and thermal analysis experiments show that when manufactured by Al12Si-HTC alloy, the surface temperature of chips in the enclosure is reduced by 2.0~4.5 ? and the temperature distribution is more homogeneous compared with traditional Al12Si alloy.

Jan 1, 2015

By F. Baczek, S. S. Rocks, D. Chaiko, C. Eyzaguirre, S. Asihene, T. Walters

The majority of efforts to improve primary copper sulfide leaching have focused on solution chemistry, temperature, O2 pressure, ultra-fine grinding, the use of catalysts, etc. Historically, very few studies have focused on the solid/solution interface. A new, patent pending approach to catalyzed, copper sulfide leaching has been discovered by FLSmidth that enables manipulation of the 2-D semi-conductor properties of chalcopyrite surfaces to the benefit of higher electrochemical reactivity. Copper dissolution rates are then further accelerated by incorporating a Stirred Media Reactor (SMRt) into the process. By using minute amounts of Cu2+ to "pre-activate" chalcopyrite, leach times have been reduced from >20 hours with incomplete Cu dissolution to <2 hours with 98+% Cu dissolution at 80°C. The pre-activation process takes only minutes to complete at temperatures of 80°C or less. The total atmospheric leaching process, incorporating the pre-activation and Stirred Media Reactor is compatible with existing SX/EW processes. Results of batch leach testing are presented and possible mechanisms are discussed.

Jan 1, 2015

By H. Tsuruta, A. Fujibayashi, I. Sumi, A. Murao, R. Murai

Injection of biomass into blast furnace as alternative reducing agent is so effective for the purpose of mitigation of carbon dioxide emissions from steel industries, because biomass is considered to be carbon neutral raw materials. Certain amount of Palm Kernel Shell (PKS) is abandoned after Palm oil extraction process. To use as a reducing agent of blast furnace, PKS was carbonized and classified by 100 mesh sieve. To examine the gasification behavior of PKS carbide under the blast furnace conditions, several combustion experiments were conducted using hot model experimental furnace. The experimental results showed that the gasification efficiency of PKS carbide increased as the quantity of volatile matter increased. This tendency is the almost the same for the pulverized coal, so carbide of PKS can be used at blast furnace at appropriate amount of volatile matter that can be controlled by carbonization condition. In addition, the pressure drop of the furnace tends to decrease because the amount of ash in PKS carbide may be smaller than that of pulverized coal. PKS carbide is a suitable reducing agent in that respect.

Jan 1, 2015

By Chris Twigge-Molecey

"Over the last 50 years there has been a dramatic evolution in the metallurgical engineering field in Canada. In the 60s the field was dominated by large American and UK groups, often selling major process and equipment packages. The local content was limited to wrap around facilities and the civil and structural work. The mining and metallurgical companies had strong internal teams to lead these projects. Over the decades and business down cycles the large foreign contractors disappeared or re-structured and the mining companies largely shed their engineering and project management groups. The resulting gap was filled by a cadre of local specialist engineering companies, some of whom have grown to be world leaders in the field. The paper traces this evolution and examines the underlying causes and consequences."

Jan 1, 2015

By E. Ghali

"Corrosion of support system components (e.g., bolts, mesh, plates) is a safety and economic concern in underground mines. This paper reports the results of a five-year study wherein corrosion coupons were installed at select locations in participating mines, recovered at regular intervals, analyzed for signs of corrosion, and tested to quantify loss in capacity. Complementary tests were conducted on recovered mesh and friction bolt specimens. The data provide insights into contributing factors for support systems corrosion, which aid in the selection of appropriate support strategies and reliable assessment of the useful life and need for rehabilitation of a support system.RÉSUMÉ La corrosion des composantes des systèmes de soutien (p. ex. boulons, grillages et plaques) est une préoccupation économique et de sécurité dans les mines souterraines. Cet article présente les résultats d’une étude de cinq ans pendant laquelle des coupons de corrosion ont été installés à des endroits spécifiques dans les mines participantes; ces coupons ont été retirés à des intervalles réguliers, analysés pour des signes de corrosion et mis à l’épreuve pour quantifier la perte de capacité. Des essais complémentaires ont été effectués sur les grillages récupérés et sur les échantillons de boulons d’ancrage. Les données aident à comprendre les facteurs qui contribuent à la corrosion des systèmes de soutien, ce qui est utile dans le choix de stratégies appropriées de soutien et pour une évaluation fiable de la durée de vie utile et du besoin de remise en état d’un système de soutien."

Jan 1, 2015

By B. Yu, S. Kelebek, C. Gibson, M. Aghamirian

There are a number of high grade niobium deposits worldwide which have been deemed untreatable by flotation due to the very fine grained nature of the in situ pyrochlore, the primary niobium bearing mineral. A known method of recovering extremely fine particles is through the use of chelating reagents such as hydroxamic acids which have a strong affinity for transition metals. However, one of the major issues in the flotation of niobium bearing minerals using hydroxamic acids is the corresponding recovery of other transition metal gangue minerals including magnetite, hematite, and pyrite. In order to better understand the differences in behavior of niobium and iron bearing minerals in flotation with benzohydroxamic acid (BHA) and sodium hexametaphosphate (SHMP) at a range of pulp temperatures, a Box-Behnken experimental design was employed. Regression models for the global recovery of iron indicated that iron mineral recovery was significantly influenced by both BHA and SHMP dosage. Upon examinination of flotation products by semi-quantitative XRD, it was observed that recovery of iron oxide and sulphide minerals (hematite, magnetite, goethite, and pyrite) was problematic at high benzohydroxamic acid dosage, while sodium hexametaphosphate was mainly helpful for carbonate mineral depression. Iron rich carbonates (likely an iron rich dolomite) largely reported to the tails with increased SHMP dosage.

Jan 1, 2015

By M. A. Sobhi, L. Li

With the continuous reduction of mineral resources at shallow depth, more and more mines have to go deeper beneath the earth's surface to reach the ore zones. This increase in mine depth leads to a natural stress increase, which also raises the stresses around mine openings. This may result in ground instability, including the risk of rock bursts or exceedingly large opening closure. Stope backfilling is a well known solution to improve the ground stability condition. It also has the advantage of reducing the mining wastes disposed on surface, thus helping to reduce the environment impact from the industry. However, most available solutions for backfill design were developed for an isolated stope without taking into account the influence of mine depth, except for a few numerical analyses performed recently by Falaknaz and coworkers for the case of multiple backfilled stopes laying in the same level. In this paper, a numerical study is carried out to evaluate the stresses in backfilled stopes overlying a sill mat. The mine depth and the excavation of the underlying stope below the sill mat are both taken into consideration. Compared to the case of a single isolated backfilled stope, the obtained numerical results show that the stress magnitudes in the overlying backfill are considerably increased due to the excavation of the underlying stope. In general, the stresses increase with mine depth and backfill stiffness, but decrease with an increase in the surrounding rock mass stiffness. These results indicate that the barricade and sill mat backfill design should take into account the excavation of the underlying stope and the mine depth.

Jan 1, 2015

By M. D. Evans

"Note: The views expressed herein are those of the author, not of the Government of CanadaThe mining industry has a significant opportunity to capitalize on past learnings to build better social relationships. The industry’s relationship with society is critical and under pressure. Rising levels of public opposition and social conflict are already having material impacts on operations around the world. The industry has an opportunity to shape the future direction of this social engagement, build public trust, and proactively respond to a material risk to operations, but first it needs to better understand the nature of the challenges and the urgency of addressing them.RÉSUMÉ L’industrie minière a actuellement une excellente occasion de tirer profit de ses expériences antérieures pour établir de meilleures relations sociales. Les relations entre l’industrie et la société sont critiques et elles subissent de grandes pressions. L’escalade de l’opposition par le public et les conflits sociaux ont déjà des impacts physiques sur les opérations partout à travers le monde. L’industrie a l’occasion de façonner la future direction de son engagement social, d’accroître la confiance du public et de répondre de manière proactive à un risque matériel aux exploitations, mais elle doit tout d’abord mieux comprendre la nature des défis et l’urgence de les traiter."

Jan 1, 2015

By B. H. Sadagah

"Construction of mountain roads at north westerly Saudi Arabia is a difficult task in rugged terrains, where the rock masses are steep slopes, and full of geomorphological constraints.Werka descent lies at the north west region of Saudi Arabia. The Werka descent, constructed four years ago harmed due to rainstorm. The rock masses are metabasalt and metaryolite tuff rocks. The road is eight m-wide, surround by unsupported sharp manmade slope cuts, reaches up to 15 to 40 m height on both sides. Failures took place at both sides of the road, and blocked it. The road of almost 2 km long subjected to all modes of slope instability such as rockfalls, manmade slope failures and debris flows in the absence of the remedial measures. The very precipitous 40 m-high rock slope-cut along the road has no benches, backed by a natural slope of almost 80 m height. Both types of slopes suffer from rockfalls and slope failure’s incidents, frequently took place mainly in rainy seasons. The steep manmade rock slope cut is less than 1 m close to the road, with no ditches, form a potentially source area for rockfall’s hazards.Intensive geotechnical study includes utilization of the RMR and GSI rock masses classifications indicates that the rocks are fair to poor quality. The DIPS, RocFall, Swedge, RocTopple, RocPlane computer program, in addition to GIS and DEM image utilized to perform modeling and deterministic analysis, in order to suggest the mitigation measures for the natural and manmade slope cuts and rockfalls. The seismic coefficients of 0.1 to 0.4 taken into consideration in modeling processes. Input parameters to model the rockfalls and slope failure’s characteristics were studied such as GSI, block size; seeder points, locations of fallen blocks; slope angle, restitution coefficients, and slope roughness. The programs modeled the proposed location, height and energy of the rockfall barriers, collectors, and rock bolts. Two manmade slope cuts studied and modeled utilizing the integrated techniques were to eliminate the risk of slope failures and rockfalls through the construction of remedial measures, this is the study objectives."

Jan 1, 2015

By X. -G. Chen, E. M. Elgallad

Direct chill (DC) cast ingot plates of 2xxx alloys have been increasingly used for large mold applications in the plastics and automotive industries. A novel heat treatment practice for Al-3%Cu-1%Mg DC cast ingot plates has been developed, involving solution treatment, furnace cooling to the desired aging temperature and holding for appropriate time at the aging temperature. The mechanical properties of the plates were studied for different combinations of aging temperature and time, using hardness measurements and tensile testing. The evolution of the strengthening precipitates was investigated under different cooling rates corresponding to cold water quenching, still-air cooling and furnace cooling, using electrical conductivity measurements. The results showed that by applying the novel heat treatment, the cast ingot plates could provide a wide range of combinations of strength and ductility satisfying the design specifications of large molds. This, in turn, offers a practical solution for the fabrication of extremely large DC cast plates combining between good mechanical properties and low levels of residual stress using the shortest possible heat treating cycle.

Jan 1, 2015

By T. R. Kostecki, J. Hirschi

"Analytical engineering design is based upon a trial-and-error iterative and deterministic process. Within this process, the engineer obtains some estimated values, plugs them into de facto closed-form equations, and receives output, which is expected to be a single number that serves as the basis for the design. This number is typically a factor of safety, or some other equivalent strength-stress ratio. This provides the engineer with a quick and relatively quantitative design methodology. This can create problems however, because in mining applications, the actual in situ system is highly variable, complex and often chaotic, which can lead to potentially incorrect conclusions that result in unsafe designs. A more appropriate and reliable approach is a probabilistic analysis for engineering design. This process is used widely in civil and other engineering disciplines, but is often overlooked for applications in coal mine design. Additionally, it seems the amount of past studies using this approach, especially in coal mine design, are rather limited. Considering how the probabilistic approach can account for uncertainty in parametric values and how unpredictable a mining design can be, the authors believe that this approach has potential in mining. This paper will focus on a summary of past studies related to probabilistic analysis in coal mine pillar design and provide recommendations for future work that could improve design reliability. INTRODUCTIONFeasibility and fundamental design procedures for excavations often start with an assessment of mine openings, pillar design, and the surrounding structure by using a deterministic approach with closedform solutions (ex. Bienawski, Obert-Duvall). These are reliable methods, but designers know that the inputs in these closed-form solutions are estimates at best and do not incorporate any degree of uncertainty. This is therefore not an optimal design procedure.A more appropriate design should incorporate some uncertainty because of the chaotic and variable nature of geology and mining conditions in general. In an attempt to account for uncertainty, a probabilistic approach can be adopted, which accounts for deviations in variables and provides a more optimum design solution. By applying a probabilistic approach, a designer can look at multiple failure scenarios at the same time instead of using the same deterministic design over and over."

Jan 1, 2015

By Saikat Chatterjee, Xintong (Brett) Liu, Kinnor Chattopadhyay

Magnesia carbon bricks are commonly used in BOFs and are generally pre-heated before the BOF goes into service. Owing to very stringent emission regulations, the BOF pre-heating process need to be controlled and optimized so that, the emission standards are met. One of the major concerns in organic emissions are its stringent limits on emission rates and total volatile emissions. In the present work, an attempt has been made to integrate CFD and Thermodynamic models to predict the emission rate of volatile organics during the pre-heating process. A one dimensional heat transfer model was developed using visual basic and then integrated with thermodynamics calculations using FactSage 6.4. The parameters that affected organic emissions were the pre heating procedure, gas composition of the burner, heating rate and type of the burner. Typical composition of MgO-C bricks and binder materials were obtained from literature and vendor data sheets. Chemical reactions between organic materials, refractory and burner gasses were considered. The model predictions indicated that certain burner conditions could destroy all organics before it exits the vessel while other conditions needed the use of an after burner at the mouth of the vessel. The model was also able to predict the organic emission rates based on the chosen pre-heating profile. This kind of predictive model will be very useful for the steel industry and enable them to justify permit limit applications and stick to the limits by fine tuning their pre-heating process.

Jan 1, 2015