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By Marko Oosthuizen, Charl P. Botha, Lidia Auret, Annelette Malan, Marthie de Leeuw

Flotation performance is affected by upstream disturbances (e.g., mineralogy, water quality, flow rate) and controlled variables (e.g., pulp level and air addition). Process disruptions can lead to undesired conditions, such as pulp overflowing flotation cells (with insignificant/absent froth, and thus no valuable mineral concentration). Early detection and appropriate intervention of pulping events improves concentrator performance. An approach to real time flotation pulping event detection by means of convolutional neural networks is presented, including a case study of the industrial application of this technology on three flotation banks.

Feb 22, 2026

By Richard A. Thomas, III JAMES H. ROWLAND, Liming Yuan

This paper presents the results of large-scale fire experiments on evaluating the performances of carbon monoxide (CO) and smoke sensors at low ventilation velocities. Experiments using three different combustibles — conveyor belt, coal and diesel fuel — were conducted in the experimental mine at the U.S. National Institute for Occupational Safety and Health (NIOSH) Bruceton Research Facility. A total of eight sensor stations were located downstream of the fire with each station containing sensors for CO, smoke, carbon dioxide (CO2 ), oxygen (O2 ), humidity, barometric pressure and temperature, as well as two airflow sensors. The airflow velocity ranged from 0.22 to 0.26 m/s (44 to 51 fpm) in the tests. The response times were recorded for the CO and smoke sensors at each sensor station when smoke and gaseous products of combustion from each burning combustible reached the station. The response times of the CO sensors were used to determine the appropriate sensor spacing in the belt entry with a low air velocity. The performance of the smoke sensor was found to be affected by the high humidity in the experiments. The results on proper selection of sensors and the determination of sensor spacing at a low ventilation velocity can be helpful for ensuring sufficient early fire warning for underground workers, thereby improving the health and safety of miners.

By K. Sasaki, S. Kuroiwa, H. Miki, Y. Aoki, T. Hirajima, Y. Orii, G. P. W. Suyantara

Selective flotation to separate copper minerals from, for example, Mo- and/or As-bearing minerals is a continuing problem because the selectivity of current systems is imperfect. Selective Cu-As flotation is currently difficult, and the most common Cu-Mo selective flotation method uses NaHS; this must be done in an enclosed system because, under acidic conditions, this method produces hydrogen sulfide. In this paper, some novel alternative flotation processes that use redox reactions are discussed; these methods have a much lower environmental impact. Oxidation and reduction reactions can be used to make copper minerals more hydrophilic and Mo-bearing minerals more hydrophobic. X-ray photoelectron spectroscopy (XPS) analyses indicated that the copper minerals became hydrophilic because hydrophilic iron precipitated and several hydroxides covered the copper minerals’ surfaces, whereas the molybdenum minerals remained hydrophobic because their sulfide surfaces were not covered. Flotation experiments on these minerals after redox treatments indicated that excellent separation of Cu-minerals from Mo-minerals can be achieved. Possible mechanisms for this separation were investigated using detailed surface analyses and thermodynamic calculations. The additives used to initiate the redox reactions are easy to handle and make these new flotation procedures better than current processes because the new methods do not emit effluent gas and because they are commercially viable. Keywords: Flotation; chalcopyrite; molybdenite; oxidation; reduction

Jan 1, 2020

By J. E. Lema

America's bulk commodity transportation systems have taken on a new look in the 1970's and 1980's. Railroad systems, barge lines providing inland and intra- coastal waterway transportation, and Great Lakes carriers have undergone substantial changes through mergers and acquisitions, consolidations of ownership and control, and construction of modern intermodal transportation facilities linking railroads and water carriers. The new look has generated some concerns and opportunities with regard to producers and shippers of bulk commodities which are characterized by the necessity of moving large quantities of heavy materials long distances. Clearly such transportation requirements call for efficient railroad and water carrier services. Shippers of commodities like coal, grain, .chemicals, minerals, ores, forest products, petroleum products, and heavy manufactured goods find reductions in transportation competition lead to concerns that rates charged by carriers will not be sufficiently constrained by market forces. At the same time, new policies on contracting for railroad services can lead to greater efficiencies, a rewarding opportunity for carriers which should be shared with shippers and consumers of bulk commodities. Then, of course, there's a related problem that in the absence of effective competition, the benefits of increased carrier efficiency will not be passed on, in part, to shippers and consumers, causing losses in markets for producers.

Jan 1, 1986

By Xiaodong Yu, Jinxia Zhang, Fusheng Niu, Hongmei Zhang

The three-dimensional (3D) fractal dimension is an important parameter to analyze the 3D structure and flocculation effect of the hematite flocs. In this work, the 3D fractal dimension of hematite flocs was predicted by establishing the particle swarm optimization (PSO) algorithm optimized with the back propagation (BP) neural network (PSO-BP). The proposed model considers four factors, namely, the flocculant quantity, flocculation time, stirring speed, and temperature, as the input parameters. We normalize the input data during the preprocessing stage. The BP neural network was optimized by using the PSO algorithm for realizing the 3D fractal dimension. The prediction accuracy and effectiveness of the model were evaluated. The experimental results showed that the predictions performed by the proposed PSO-BP neural network were better than that of BP neural network. In addition, the root mean square error (RMSE), mean squared relative error (MSRE), mean absolute error (MAE), and mean absolute relative error (MARE) of the proposed model are lower, compared with the errors of the BP network. Similarly, the measurement coefficient R2 of the proposed model is higher, compared with the BP network. The maximum absolute error of the model is 0.0772, the maximum relative error is 0.02405, and the regression coefficient r is 0.98592. These results showed that the proposed model has a good performance and high prediction accuracy. When verifying the practicability and the effectiveness of the proposed PSO-BP model, the prediction results of 10 groups of hematite flocculation experimental data under different conditions showed that the prediction value of the proposed PSO-BP model was closer to the ground truth as compared to the BP model. Therefore, the proposed model is suitable for predicting the 3D fractal dimension of hematite flocculation.

Oct 3, 2022

By Mansoor Barati

The present paper is based on a term project for final year undergraduate students, requiring them to evaluate a process for producing silicon from rice husk. The traditional method for production of silicon involves carbothermal reduction of quartz in electric arc furnaces at temperatures exceeding 2000 °C. The technology consumes a considerable amount of electrical energy as well as fossil fuels, resulting in significant CO2 emissions. A flowsheet for production of silicon metal from rice husk is laid out in this paper. The technology will consist of combustors, which will generate steam using the rice husk biomass, power generator, and electric furnace for reduction of the rice husk. Materials and energy balance calculations presented here indicate that such process can be operated independent of external electricity.

Jan 1, 2014

By Bai-ru Xia, Cang-qin Jia, Qi-wu Huang

Limit Analysis Theorems has revealed to be a powerful tool for the development of numerical models aiming the determination of the load bearing capacity of structures reached by plastic collapse. This work presents a numerical formulation for the computation of strict upper bounds of the collapse loads of rigid-perfectly plastic mechanical systems, derived within the kinematical theorem framework. A key advance of this present method is that the problem is described only in terms of nodes and discontinuities connecting those nodes rather than element or bodies. The alternative approximation procedure to the traditional finite element method might involve discretization of a given body using a suitably large number of nodes laid out on a grid, with the failure mechanism comprising the most critical subset of potential discontinuities interconnecting these nodes. Potential discontinuities which interlink nodes laid out across the problem domain are permitted to crossover one another, giving a much wider search space than when such discontinuities are located only at the edges of finite elements of fixed topology. Highly efficient interior point method solvers can be employed when certain popular failure criteria are specified (e.g. Mohr-Coulomb). By adopting this processing approach it is possible to solve very large problems which normally exceed the memory capacities of a single computer. The developed numerical tool reveals to be robust and versatile, able to solve a wide range of 2D problems. Velocity singularities are automatically identified and visual interpretation of the output is straightforward. Several numerical examples including rock slope are studied by the new method, and the results are very close to those calculated by using analytical method and FEM.

Jan 1, 2015

By R Sinclair, D Landwehr, I Hunter

"The Syama Gold Mine, located in southern Mali, was established in 1990 by Broken Hill Propriety Limited (BHP). The operation began treating oxide, and in 1994 it transitioned to processing hard and refractory ore based on ‘whole-of-ore’ roasting. In 1996, BHP was succeeded by Randgold Resources and the operation ran until 2001, when it was placed into care and maintenance.The Syama ore is classified as a double refractory ore with pyrite occluding the fine grained gold present in the ore and high levels of organic carbon presenting a challenge in terms of preg-robbing behaviour. The ore is extremely competent and this combination of metallurgical features was the main source of metallurgical problems encountered by the previous owners.Resolute Mining Limited (RML) acquired the Syama project in 2004. Following a feasibility study and the development of a revised processing flow sheet the plant was recommissioned in 2008 using a combination of old and new equipment. The revised flow sheet enabled primary sulfide ore to be treated by flotation and roasting of the concentrate to produce a calcine suitable for conventional carbon-in-leach (CIL) processing.Commissioning and ramp up of the plant was a troubled process, with monthly gold production being as low as 3000 oz in 2010. Poor availability of equipment and lower-than-forecast recoveries were the primary contributors.During the last five years, RML has utilised a systematic approach to improve production, focusing on mechanical reliability, metallurgical recovery and process bottlenecks. Modifications to the circuit have been as a result of both innovation and the application of technological improvements. Improvements have been made to the flotation, roasting and CIL circuits and RML has introduced a deslime circuit to treat flotation concentrate, in addition to the very successful commissioning of a new 1 Mt/a oxide circuit in December 2014. These changes have resulted in gold production increasing to more than 20 000 oz per month in 2015.This paper presents the processes, change implementation and outcomes of the modifications made to the sulfide circuit to address the availability and recovery problems.Apart from the expansion of an existing, world-class deposit and discovery of new resources, future improvements on the path to a class-leading gold mine include the continued reduction of the unit cash cost, increase in overall sulfide circuit gold recovery, increased throughput through continued innovation and consistency in the plant’s operation.Citation:Sinclair, R, Hunter, I and Landwehr, D, 2016. Syama Gold Mine - the Journey towards a Class-leading Gold Mine, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 213–224 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Michael Gebman, Jack Gerwick

"With the opening of the new San Francisco-Oakland Bay Bridge East Span, the former bridge and its caisson foundations are being demolished. Caisson foundations are in the path of a future shipping channel and therefore need removal down to the mudline 50 ft below water (MLLW). For the first caisson to be removed (E3) a mechanical demolition was performed above the waterline and an implosion was done for the remaining caisson down to mudline. Mechanical demolition consisted of excavators operating from either on top of the caisson, from work platforms or from barges. The demolition was implemented on a trial basis with a successful implosion on November 14, 2015. The work was conducted in an environmentally sensitive area, with measures taken to protect fish, marine mammals and birds. This demolition technique was cost effective, faster to execute, and had a better environmental impact then an alternative option. The demolition, measures implemented to protect the environment, outcome, and lessons learned are presented.INTRODUCTIONThe California Department of Transportation needed a cost effective and environmentally friendly solution for removal of the remaining San Francisco-Oakland Bay Bridge (former East Span) caisson foundations, starting with caisson E3. This was necessary to clear a future shipping channel. One option was to construct a steel cofferdam around the caisson to allow demolition in the dry down to the mudline. This option would take years to complete, be cost prohibitive, and its noise would disrupt aquatic life and birds throughout the cofferdam construction and demolition. An alternative option was implemented on a trial basis to conduct a mechanical demolition of the caisson above waterline along with an implosion of the remaining caisson down to mudline. This had the clear advantage as a cofferdam was not needed, and the demolition project duration would be approximately 6 months, instead of several years for the cofferdam option. The potential impact on aquatic life and birds from the implosion was a concern, as the location is environmentally sensitive; however, measures were implemented to minimize these impacts. As presented in this paper, this demolition option was implemented on a trial basis for Caisson E3. The technique succeeded and will now be used on the remaining caissons.BACKGROUND INFO ON CAISSON E3The reinforced concrete Caisson E3 is the largest caisson which supported the former East Span of the Bay Bridge. It was constructed in 1934, with the Bay Bridge opening in 1936. Figure 1 shows the project location. The caisson had a cell arrangement of 7 x 2 above the mudline. Below mudline, the caisson had a cell arrangement of 9 x 4. A structural transition was made between the 7 x 2 and 9 x 4 cell arrangements with buttress walls. All cells were flooded, as underwater openings were included in the original caisson walls to equalize the hydrostatic pressure. Figure 2 shows the caisson layout with limits for mechanical demolition and for the implosion."

Jan 1, 2016

By ANGELA NAIR AVELAR, Reiner Neumann, PAULO R. G. BRANDÃO

The understanding of the influence of the different types of apatite on the performance of mineral processing of igneous phosphate ores is still a challenge due to the difficulty to explain why some types of apatite floats in the froth flotation cell and others do not under the same conditions. Three types of apatite were identified by means of cathodoluminescence (CL) images in flotation concentrate and tailing samples from the Catalão mine: predominantly blue apatite, followed by green apatite and less frequently yellow apatite. The chemical composition of these types of apatite was determined by electron microprobe analysis (EPMA) and LA-ICP-MS. Blue and green apatite respond well to the process, thus remaining in the concentrate, while yellow apatite remained in the tailings. Yellow apatite is the one bearing the lowest P2O5 content and the largest anionic and cationic sites substitution, followed by green apatite, whereas blue apatite is the most homogeneous, with highest P and Ca grades and lowest substitution level. A negative correlation of the amount of phosphorus with fluorine was observed. Furthermore, impregnation of iron oxide-hydroxides in the yellow apatite was also observed. Therefore, the low flotation behaviour is due to low crystallinity coupled with impregnation onto its surface.

Jan 31, 2022

By K. Kawagishi, K. Matsumoto, Y Koizumi, H. Harada

A new burner rig for cyclic and hot corrosion testing of Ni-base superalloys and high-temperature coatings has been developed at the National Institute for Materials Science (NIMS) in Japan. The concepts of the rig design include: use of kerosene as fuel, easy operation for materials research and multi-specimen testing capability per test run. The burner rig consists of six blocks including combustion block, corrosion-solution injection block, furnace block, specimen block, controller block and outdoor facility block. During verification testing, it was confirmed that the rig had accurate specimen temperature control within ±1? from 600 to 1100? and automated easy operation. Cyclic testing of several Ni-base superalloys was conducted. The results from 50 cycle testing indicated that a new NIMS alloy developed for 1700? class gas turbine had higher oxidation resistance than CMSX-4. This new burner rig testing capability at NIMS can be very useful for future oxidation, hot corrosion and coating durability studies.

Jan 1, 2010

By N. Saracoglu, J. P. Golightly, R. H. Wallis, J. J. Brummer

"The McClean uranium deposits are located 11 km west northwest of the Rabbit Lake Mine. Their average grade is 1.8 % U3O8 , and they contain 6. 350 tonnes of uranium oxide in seven pods of variable grade and mineral assemblage. They are hosted by both basal Athabasca Group and the regolith developed on the underlying crystalline basement. The major mineral facies are: sulphide, arsenide, 'bleached', and hematite, with the important uranium minerals being coffinite, uraninite and pitchblende. Abundances of carbon and sulphur isotopes are consistent with their derivation from pyritic graphite in basement gneisses. Isotopes of oxygen and hydrogen suggest equilibration at temperatures of about 200°C. Ar39/ Ar40 age determination of illite associated with ore suggest mineralization began about 1300 m.y. ago and that significant alteration had ceased by about 1170 m.y. ago though Pb/ U data suggest the deposits continued to evolve into the Mesozoic.IntroductionThe McClean deposits lie on the eastern side of the Athabasca Basin of northern Saskatchewan where they are part of a cluster of uranium deposits lying west of Wollaston Lake (Fig. 1). The general stratigraphy is schematically portrayed in Figure 2 which emphasizes that mineralization is hosted by both the Athabasca Group and the underlying regolith and also that the deposits are preserved at depth and have not suffered from preand post-Pleistocene weathering and erosion. This circumstance, combined with their simple shape and the presence of seven separate zones of mineralization (pods) allows a description, based on over 450 fully cored drill holes, to be made of the wide variation in chemistry, grade, alteration patterns and position relative to the sub-Athabasca Group unconformity. Ar39 / Ar40 age determinations have been made of illites associated with regolith, Athabasca Group and mineralization and studies are in progress on C, S, 0 and H isotopes of mineralized material and host rocks. Only some of these data have been published; Brummer et al., (1981); Golightly et al., (1982); Bray et al., (1982); and Saracoglu et al., (1983). The only other published data on McClean geology are by Tremblay (1982, 1983)."

Jan 1, 1986

By N. Gritzuk

The area of Canada with which we are here concerned consists of Yukon Territory and Northern British Columbia. Generally it lies west of the coastal mountain range and access to the sea can be gained at only selected points which are relatively few. It is served by the Alaska Highway as well as a provincial and territorial system of roads permitting transport of mining products to Whitehorse in Yukon Territory. This town it the northern terminus of the White Pass and Yukon Route, which system provides a rail service between Whitehorse and Skagway, Alaska a distance of 110 miles, and thence to Vancouver, British Columbia, by the coastal Motor Vessel C. J. Rogers, a distance of an additional 890 miles. At present the service between Vancouver, B.C. and Whitehorse, Y. T. is on a fourteen day basis. The coastal vessel, capable of carrying 3,200 tons of cargo, was specially designed and built in 1955 for handling containerized cargo and general cargo northbound, and containerized and palletized asbestos fibre, and palletized lead and zinc concentrates southbound.

Jan 1, 1961

By Olav Moklebust

The R-N Process is an outgrowth of the development by the National Lead Company's Norwegian subsidiary Titania A/S, of a process for producing metallic iron and a high titanium content co-product from ilmenite. Development of the process for the treatment of iron ores was continued as a joint project of the Republic Steel Corporation and the National Lead Company in 1953. More recently in July, 1957, the R-N Corporation was created by these two companies to undertake the commercial promotion of the results of this joint project. This paper has been prepared with the permission and encouragement of these three companies. The R-N process has as its objective the making of metallic iron from iron ores or iron ore concentrates. The general principles of the process have already been disclosed in technical papers and patents. In general the process comprises the following steps: 1. Iron oxide in crushed natural iron ores or iron ore concentrates is reduced to about 95% metallic iron, without fusion in a rotary kiln in the presence of solid carbonaceous fuel,*such as, coke or char, limestone and combustible gases. 2. The kiln discharge, consisting of metallized ore, coke, lime and coke ashes, is cooled. The excess coke is regenerated and recycled to the kiln feed.

Jan 1, 1959

By L. H. Monaco

"The evolutional process is always about solving existent problems in order to provide further achievements. But the more something evolves, the more challenges it faces towards greater evolution. Industrial automation systems in Mining have also evolved a lot in the past decades, but they now face new challenges about integration: how to integrate different locations and systems, in a way to reduce costs and increase overall mine efficiency and safety for the operation. This paper compares conventional mining process automation architectures vs. a state-of-the-art, completely integrated system using Electrical Integration based on IEC 61850 standard for Substation Automation Systems. Emphasis is placed on the benefits to manage the entire mining plant as a whole, not only looking at the production rates, but also at the energy consumption for each part of process. In addition, it is discussed how an integrated system approach unlocks safety and productivity gains such as overall process optimizations, improved operator effectiveness, increased plant availability, and reduced maintenance costs. INTRODUCTION The world is constantly changing, and evolution is a natural part of mankind history. The role of evolutional process is to solve existent problems, but usually these solutions create new issues that need to be addressed. This scenario is also applicable to the industrial environment, in which the demand for higher profitability and efficiency on their processes requires solutions with more productivity using less resource. This is not different when it comes to energy consumption: how to optimize production rates and reduce energy costs at the same time? Regarding automation systems, the trend for the industries is to focus on four main challenges: how to provide safety for personnel; how to reduce initial investment for new plants; how to connect remote and in harsh locations; and above all how to deal with the lack of integration between several systems."

Jan 1, 2018

By Willy Ank de Morais

Este trabalho teve como objetivo analisar, através da fractografia, o desempenho de aços inoxidáveis Duplex 2205 soldados por três processos diferentes: FCAW - Flux-Cored Arc Welding (Arame Tubular), o GTAW - Gas Tungsten Arc Welding (TIG), e o SMAW - Shielded Metal Arc Welding (Eletrodo Revestido). A superfície de fratura das amostras foi obtida através de ensaios de tração, nos quais foram registradas as respectivas curvas tensão-deformação completas, que também foram analisadas. Os resultados mostraram que o tipo de influência da solda nas propriedades mecânicas analisadas.

Oct 30, 2017

By F. A. Rutledge

"The W. E. Dunkle mine, sometimes called the Costello Creek coal mine, is 8 miles N. 20° W. of Colorado Station on the Alaska Railroad. The presence of coal in this area has been known since the district was extensively pros¬pected for gold between 1911 and 1915. At that time, coal from this deposit was used by miners for blacksmithing. The increased demand for coal resulting from government defense projects in Alaska led to exploitation of this deposit in 1941.The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska was responsible for establishment by the Army of the Coal Procurement Section of its Alaska Department. It proposed to investigate the deposits and to expedite production from the Alaskan coal fields. The Bureau of Mines closely cooperated in this program.The quality of the Dunkle coal and the favorable location of the deposit caused it to be one of the properties chosen for investigation under a joint Army-Bureau of Mines-Geological Survey program.During July 1943, the coal area in the immediate vicinity of Costello Creek was geologically and topographically mapped. by Clyde Wahrhaftig and Jacob Freedman, geologists, U. S. Geological Survey. F. A. Rutledge, mining engineer of the Bureau of Mines examined the property July 18 to 22, 1943, and a project of trenching, diamond drilling, and sampling was initiated on August 4, 1943. During the project Clyde Wahrhaftig remained at the Dunkle mine to interprets drill cores and assist the author in planning the explora¬tory program. The project was completed October 7, 1943.Field investigations were under the general direction of R. S. Sanford, acting chief, Alaska Branch, Mining Division. Coal analyses were made by Maurice L. Sharp, coal analyst for the Alaska Railroad.Special mention is made of the cooperation and assistance received from Clyde Wahrhaftig, geologist, U. S. Geological Survey.The many courtesies received from the owner, W. E. Dunkle, and the members of the Army Coal Procurement Section, Alaska. Department, also are acknowledged.The W. E. Dunkle coal mine is in the Broad Pass region on the south slope of the Alaska Range at an altitude of 2,800 feet (fig. 1). It is situated within the Third Judicial Division, headquarters of which is Valdez, Alaska. The area is situated approximately at latitude 63° 15' N. and longitude 149° 30' W. and is connected with the Alaska Railroad at Colorado Station by an 11-mile gravel road that is passable throughout the year. This road is maintained by the Alaska Road Commission. A private telephone line to Colorado Station connects with the telephone and telegraph service of the Alaskan Railroad.The passenger rate from Anchorage, Alaska, to Colorado station is $12.10. Freight rates are $1.60 a hundred pounds for heavy machinery and $2.66 a hundred pounds for first-class freight.The Costello Creek coal basin is in an area of low relief and has been dissected by numerous creeks flowing down the south flank of the Alaska Range. The Dunkle coal mine is on Coal Creek, a small tributary of Camp Creek, 1,000 feet from their junction. About 700 feet below this junction, Camp Creek joins Costello Creek, which in turn empties into Bull River 1/2 mile above the latter's confluence with the West Fork of the Chulitna River. The location of the mine is shown on figure 1."

Oct 1, 1948

By Haydn H. Murray

This paper presents the results of test work performed with a Pacific Electric Motors (PEM) high intensity magnetic separator (20 kilogauss) , a unit capable of separating weakly, as well as strongly, magnetic minerals in the particle size range of sands to clays. Tests were performed on some 40 industrial minerals. With some minerals excellent separations were attained and with others intermediate and poor separations were accomplished. This study is a preliminary survey and many of the intermediate and poor results can be improved as separation problems are worked out with additional test work. It is demonstrated that with a number of industrial minerals high intensity magnetic separation is a viable beneficiation technique that is economic ally feasible.

Jan 1, 1976

By K Zunica, A R. Penney

The principles of three-dimensional geological modelling are well understood and routinely used. Sample data is collated and geostatistical tools used to ensure that sample data is suitable for its end use, which is typically a block model that is appropriate for mine planning. What has become increasingly apparent is that physical rock properties and geotechnical parameters need to be incorporated into the three-dimensional geological model to create an integrated mine model.The approach to the collection of geotechnical information is not as highly prescribed and controlled as collection of geological data. Commonly, the geotechnical data set is incomplete and inconsistent, with little consideration of what the end use will be by those collecting the data, or how the geotechnical data might relate to the geological data. In some cases, specific geotechnical investigation programs are completed, yet correlation between those programs and previously collected data is rarely undertaken to the same level of diligence as found in the geology field.There are some obstacles that need to be considered when attempting to incorporate geological parameters, such as grade, lithology, and geological domains with geotechnical information such as rock quality designation (RQD), rock mass rating (RMR), rock strength, and geotechnical domains into the same three-dimensional block model. Interpolation or geostatistical estimation methods used for grade estimates might not be appropriate for many components in rock characterisation, particularly search geometries. A number of examples are provided to illustrate issues underlying some of the data collection procedures, and their effects on three-dimensional geotechnical modelling.The example presented attempts to highlight generally observed shortcomings in the collection of geotechnical information, parameters which need to be considered when combining geological and geotechnical data into the same model, and the benefits of having a combined block model from the beginning of a project.CITATION:Zunica, K and Penney, A R, 2014. Integration of geological and geotechnical data for three-dimensional modelling, in Proceedings Ninth International Mining Geology Conference 2014 , pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By Jose Antonio Silva Souza, Emanuel Negrao Macedo, Iara Ferreira Santos, Otacilio Dias, Luis C. A. Venancio

"The Bayer process alumina production generates 0.7 to 2.0 ton of bauxite residue (BR) and an average of 1.0 ton of C02 per ton of alumina produced. The direct reaction of exhaust gases to reduce the alkalinity of the BR may allow a triple gain: improve the storage conditions, open a range of new applications for BR and sequester from 16 to 102 kg of C02 per ton of alumina. This paper shows the measurement of C02 captured during a pilot scale reaction of a suspension of BR in water with flue gas, produced from direct oil burning. Three different types of reactors were used: one spray tower and two packed columns. The inlet and exhaust gases were analyzed using electrochemical and non dispersive infrared sensors. The pH of the suspension was monitored during and after the reaction to evaluate the buffer effect.IntroductionAlumina is mainly produced from refining bauxite using the Bayer process. This process consists of extracting the aluminum oxide through its dissolution in caustic soda and the separation of insoluble residues. The remaining bauxite residue (BR) although not particularly toxic, poses risks to the environment due to the large volume and its reactivity. According to the latest technology it is stacked on sealed deposits specially constructed. To date the vast majority of the bauxite residue that has been produced was stored and were not incorporated into any existing production processes to significant amount with exception to some extent of the sintering process residue at Russia and China [l]. On the other hand, a strategic goal was set in 2010 by the Bauxite and Alumina Committee of the International Aluminium Institute (formed by the majority of the industries) to reuse 20% of BR in 2025 [2]. China has established the same objective for 2015[1].This paper is a sequel of two others presented at TMS 2010/2012 [3-4] and describes:• A pilot plant assembled for testing the carbonation process of BR with gaseous effluents similar of the refining process.• The methodology used to measure the amount of C02 captured during the carbonation process.• The results of the carbonation process, the C02 capture and the buffering effect of the pH.This process is studied in order to consume minimal power and use the effluent as efficiently as possible in different reactors from low cost to ultra high performance. The process is designed for minimizing the power consumption and equipment investment."

Jan 1, 2013