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By Viswanathan N. Nurni

In metallurgical processes, more and more usage of hydrocarbons is encouragedto bring down the carbon emissions. In this regard, numerous investigations onreduction of oxides by C-O-H-N gas mixture have been reported. Attempts to simulatethese reduction processes using shrinking core model, one of the commonmodels used for such studies, have under predicted the reduction rates. This maybe owing to the fact that the homogeneous reaction in the gas phase is not being considered. If the reaction temperatures are above 1000K, generally so for manyreduction processes, the homogeneous gas reaction rates are expected to be sohigh that one can assume local equilibrium in the gas phase. In the present study,reduction of wustite in a C-O-H-N gas mixture has been modeled using shrinkingcore model considering the water gas shift equilibrium in the gas while it diffusesthrough the product layer.

Sep 1, 2012

By K. Hausmann, P. A. Sashin, G. J. Prejean

Misfires caused by unreliable shock tube constructions can have significant cost implications and place field workers at serious risk during remediation. Ionomer materials, used as a subtube in shock tube constructions, provide superior hot tack strength, oil resistance, impact resistance at cold temperatures and excellent thermoformability properties. These are important features for resisting blast-throughs and ensuring blasting reliability in demanding environments, such as open pit mining in harsh environments. Superior hot tack strength, strain hardening, and excellent thermoformability properties of the ionomer materials ensure uniform powder distribution along the shock tube during construction and avoid undesired powder accumulation due to deformation or vibration during use. Oil or chemical resistance is another feature of Ionomers. This allows improved property retention in contact with oils and hence longer sleep times of the shock tube. Another feature of these highly engineered ionomers is superior impact strength at low temperatures. This plays an important role considering the resistance to fly rock impact in open pit mining operations in particular in cold climates.

Jan 1, 2011

The Technical Programme Committee-Metals Technology of The South African Institute of Mining and Metallurgy, in association with its Vaal Triangle Branch, held a one-day colloquium on 18th April, 1989, the theme being 'Ferous Pyrometalurgy: A Challenge for South Africa'. The venue was the Auditorium 100 at the campus of the Vaal Triangle Technikon in Vanderbijlpark. Project and contract management A Project and Contract Management Conference is to be held on 19th and 20th September, 1989, at the C SIR, Pretoria. Powder metallurgy The PM 90 exhibition is to be held in Wembley, London, from 2nd to 6th July, 1990. The wide range of powders, processing machinery, and powder-metallurgy components at the exhibition will reflect the growth in this highly specialist industry. Castings and forgings Exhibition organizers, FMJ International Publications Ltd, are set to build upon the success of Castings & Forgings '88, which was held as a joint event with Pat- Cast '88. Castings & Forgings '89-with Pat-Cast '89- has already generated a high level of interest, which has been reflected in the demand for stands. Furnaces FURNACES '90, the eighth in this series of exhibitions for the thermal-processing industry, will be held in Solihul, West Midlands, England, on 6th and 7th March, 1990.

Jan 1, 1989

By R. D. Shackleton

Medusa Cement Company, a division of Medusa Corporation, is a medium-sized cement manufacturer serving the midwest, east, and southeast. Medusa's eight plants are located in Georgia, Pennsylvania, Ohio, Illinois, Michigan, Wisconsin, and Canada. Of these, six have active limestone, shale, clay, and sand quarries now in operation. This paper deals with the various individual state laws regulating mining and reclamation at the Georgia, Illinois, and Pennsylvania quarries. Several recommendations for future state mining laws are discussed also.

Jan 1, 1974

By Mousaab Majar, Nikolaus Schneider

The technical challenges for accurate drilling positions increase with deep underground structures in inner city areas. Designed for jet grouting, specific sensors have been developed to record the alignment of rods during drilling by integrating microchips into the drilling rods. By feeding the rod with constant electric current, microchips, integrated in special couplings, can be read during the drilling process and tracked on monitors installed in the operator’s cockpit. The orientation for the drilling rod is provided by magnetic points and a compass, positioned above ground on the drilling rig. In combination with asymmetric drilling bits, it is now possible to steer the drilling hole to predetermined positions to compensate for deviations in deep bores. This type of drilling rod for jet grouting has been used in Berlin since summer 2019.

May 1, 2022

By ANA E. BOHE, MICCO GEORGINA DE, GASTON G. FOUGA, JUAN P. GAVIRIA, FEDERICO J. POMIRO

To the best of our knowledge, this paper comprehensively summarizes a thorough study to determine the thermodynamic viability of the reactions between light rare earth oxides and chlorine with and without carbon. The kinetics and mechanisms of light rare earth oxide chlorination and carbochlorination reactions are analyzed and discussed according to results in the literature. Lanthanides between lanthanum (La) and gadolinium (Gd) are considered as light rare earth elements (LREEs) in agreement with previous literature and the results detailed in this review. Both laboratory- and industrial-scale light rare earth chlorinations and carbochlorinations, starting from oxides and ores, are reviewed.

By W. L. Dam

Grand Junction, Colorado’s legacy with uranium mining and milling serves as a model attracting international interest. Access to water and central location to carnotite ore containing uranium and vanadium resulted in the World War II military creating a site in Grand Junction for developing extraction techniques; subsequently, several commercial mill sites were built in the area. Uranium mills produced ore into the 1970’s as well as tonnes of radioactive waste tailings. Tailings contain radium that emits radon gas. Despite the radiation hazard, sandy tailings were added to concrete and became incorporated into roads, schools, businesses and homes. Clean up of sites containing tailings and mill sites began in the 1970’s involving city, state, and federal officials. The Climax mill site had become an auto junk yard mixed with mill tailings. A new disposal site was built out of town and away from the river in the 1990’s. After Climax mill tailings were removed to the disposal site, the land sat vacant for two decades until citizens and city officials developed a masterplan for the riverfront property. The Las Colonias river park is being built in stages including an amphitheater, gardens, businesses and parks. One of the biggest obstacles to site remediation and reuse was overcoming public outrage, fear, and lack of trust which made funding sources scarce.

Jan 1, 2020

By X Li, W McKeague, M S. Powell

This paper explores the importance of operators in the overall efficiency of mineral processing plants. With the potential of future control configurations becoming more remote, it is time to review the implementation of control and utilisation of operators. This paper is based on a preliminary review of operators and control room operations and clearly shows that, in the minerals industry, operations are typically run in a reactive mode (with a focus on ensuring equipment operation), rather than in a proactive mode (with a focus on optimising the process performance). The primary reason for this misguided approach is the short sighted thinking applied to the challenges of designing technology and organisational tools capable of addressing the essential operational needs: an approach which inevitably results in a disconnect between people and technology. Contrary to the popular approach of replacing operators with expert systems, the thesis of this paper is that the shift to more complex circuits, with higher demands on processing capability and control, will require the actual upskilling of operators. Experience in mineral processing and other industries indicates that expert systems cope well with small changes but are typically unable to respond to major changes in feed material and this is where the expert operator becomes crucial. Providing operators with ongoing high level training in process understanding, and restructuring how they interact with the plant and interface with the control system is the approach being proposed here - an approach surprisingly underutilised and often absent in the minerals industry today.CITATION:Li, X, Powell, M S and McKeague, W, 2012. Unlocking processing potential by empowering our operators, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 333-340 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By J Taylor, A Dubowik

To increase the efficiency and improve the quality of diamond drilling at Olympic Dam, mine geologists have adapted and modified common practices in order to overcome the challenges imposed by such a unique environment. Mine geologists have to take into account both the complex geology during the diamond drill hole design phase, as well as incorporating diamond drilling into the larger-scale scheduling process already employed at Olympic Dam. This study seeks to explore how such modifications have evolved over time.The geology of Olympic Dam influences the design process of diamond drill holes, particularly due to the variation of lithology and alteration, as well as the presence of magnetite and major structures within the orebody. Exclusion zones are used to manage interactions with existing and planned mining activities, and their size is dependent upon the geology of the area. Specific deviation checks are used to monitor the deviation of diamond drill holes with respect to these?zones.The highly interactive environment of Olympic Dam requires unique planning for diamond drilling, resulting in the production and implementation of both long- and short-term schedules. Long-term schedules are targeted at determining drilling locations and ensuring drilling is completed prior to stope planning, while short-term schedules aid in enabling access to ensure timely set-up of drill sites. Estimated drilling rates, determined by expected lithologies and historical data, feed into the short-term schedule to assist in managing the operation and minimising the downtime of diamond drill rigs. A mine geologist is appointed as a diamond drill coordinator to organise and manage diamond drilling at a scheduling and operational level, streamlining the entire process.Analysis of historical data shows a strong correlation between implementation of the aforementioned practices and improved drilling rates. This study shows the importance of adapting universal tasks to particular environments and circumstances. Mine geologists at Olympic Dam continue to acquire knowledge to further improve the modified drilling practices as operational requirements, production pressures and economic factors change.CITATION:Taylor, J and Dubowik, A, 2014. The evolution of diamond drilling practices at Olympic Dam, in Proceedings Ninth International Mining Geology Conference 2014 , pp 271–280 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By Andre L. Du Preez

Global mine hoisting regulations require safety fall arrest systems to be installed on vertical conveyance systems capable of safely decelerating and supporting a fully loaded conveyance in the event of a rope severance. Most current arresting systems are incapable of producing controlled safe deceleration rates. Although safety ?dogs? achieve marginally acceptable results on wooden guides, difficulties arise in achieving safe deceleration performance requirement where safety arrest systems operate on steel shaft guides. Previously, arresting systems capable of operating with steel guides have been incapable of producing controlled deceleration rates during the arresting of free-falling conveyances. Most are ?instanton? systems, whereby an occupant inside a conveyance being arrested would be subjected to unacceptably high deceleration forces. This paper briefly highlights the background to the selection process of Rio Tinto?s Technical Staff of a suitable Mine Conveyance Safety Fall Arrest System for #1 Shaft at Rio Tinto Oyu Tolgoi Mine, Mongolia. It also describes the Drop Test and Free Fall Test procedure and the results leading to the acceptance of the Horne Group Levelok® Emergency Braking Technology for the Oyu Tolgoi #1 Shaft in Mongolia. The paper highlights Rio Tinto?s primary objective for the selection of this advanced technology on their primary production shaft cage system as an emergency safety catch braking system combined as an advance hydraulic chairing system. It describes the design and operational parameters and the 'Fail to Safe' interfacing with current automated mine hoist systems.

Aug 1, 2013

By Karsten Hagenah, Tor Jensen, Jens Laugesen, Øyvind Fjukmoen, Lucy Brooks

This paper describes operational environmental threshold levels for exploitation of mineral resources in the deep sea. Such criteria are needed to be able to monitor and control deep sea mining with respect to the stringent environmental requirements that are needed. It is recommended to use existing environmental threshold levels for comparable activities where such are existing. Fields of application are mainly but not exclusively seabed mining operation activities under the governance of the International Seabed Authority (ISA). The threshold levels and limits mentioned in this paper are proposed recommendations based on other activities than seabed mining but are a proven and accepted approach in other maritime industry activities. An example of such other activities with proven and accepted environmental threshold levels are Oil & Gas exploitation activities in the sea. Background The first exploitation of mineral resources is coming closer. At the moment regulations for exploitation for mineral resources in the Area are being developed by the International Seabed Authority (ISA). The ISA regulations will contain the framework related to environmental monitoring of exploitation. However, the regulations will not contain operational environmental threshold levels for the Contractor.

Jan 1, 2018

By David J. Forrester

Light metals, most commonly aluminum, magnesium and titanium, and alloys containing them, are used in many industrial applications where lightness, hardness, ductility and resistance to corrosion are needed. However, these metals and their alloys can be potential ignition sources in underground coal mines. There have been documented cases in the past where coal mine explosions have been attributed to firedamp/coal dust ignitions involving light metals or their alloys. When light metals and their alloys are brought into contact with oxygen bearing material, such as iron oxide (rust) in the presence of heat, then a "thermite" reaction can occur. This source of heat can be generated from frictional contact or from merely a glancing blow. This paper outlines the hazards associated with light alloys, how to address the hazard and regulatory aspects.

May 1, 2001

By Alexandra Garcia

A measurement-based ground control management system, commonly employed in coal mines, has been successfully implemented in a UK potash mine operating at a depth of over 800 m. This system includes the routine deployment of telltales in roadways throughout the mine to mitigate against the risk of large-scale roof falls and the deployment of detailed ?design monitoring? instrumentation for ongoing design verification. The routine monitoring systems used in coal mines have not been, to date, commonly applied in potash mines, despite the similar, variable weak geology and associated ground control hazards. Monitoring information from the site indicates that telltales can be deployed to monitor roof conditions, with action levels based on differential rates of strain, as opposed to absolute movement.

Jan 1, 2014

By J C. Koppe, L Vieira

One common problem for blasting in iron ore mines with significant weathering is the occurrence of large blocks of hard rock mixed with softer material. This situation causes a problem for blasting design and sometimes produces large boulders of rock that require a secondary blasting, as well as excavation difficulties. To minimise this situation, geophysical techniques were used to identify the hardest material amid the weathered material. To study the problem, seismic, ground penetrating radar (GPR), electrical resistivity and induced polarisation (IP) methods were used in an intensely weathered Brazilian iron ore deposit. The methods of GPR combined with IP, resistivity and seismic showed to be effective in modelling the contrast among hard, friable materials and soil. The results were used to improve the geological model and create more favourable conditions for the subsequent blast design. The blast design based on geophysical/geological models resulted in significant improvement in the fragmentation of the iron ore. This was achieved by the adoption of a specific drilling pattern for a given geological situation. With the new specialised blasting design the formation of boulders was eliminated.CITATION:Vieira, L and Koppe, J C, 2015. Geophysical techniques applied to blasting design, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 289–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By C. R. Everly

"The purpose of this paper is to review the most effective methods of reducing chloride transfer and chloride removal in the solution extraction and electrowinning (SX/EW) process. Elevated chlorides in electrolyte have various negative effects including a reduction in current efficiency, increased handling costs at rod plants and smelters, increased anode corrosion, cobalt losses due to increased electrolyte bleed, degradation of HDPE piping, and increased corrosion in the SX/EW plants. Historical controls that Sierrita has used to control chloride transfer, in order of effectiveness, have been chloride gasification at the EW that is directly correlated to amperage and chloride concentration in electrolyte, wash stage bleed and efficiency, width and velocity of aqueous bands, and electrolyte bleeds. Maintaining high bleed rates and high amperage settings has been a challenge with decreasing pregnant leach solution (PLS) grades, so keeping chlorides out of the electrolyte has become imperative. The effectiveness of reducing aqueous entrainment, optimizing wash stage efficiencies, and improving organic quality to reduce the transfer of chlorides to the electrolyte are illustrated in this study. INTRODUCTION The transfer of impurities from PLS feed streams to electrolyte in the Copper Solution Extraction process is a very common problem and is the reason that the wash stage exists in most SX operations. The main impurities affecting the SX process are iron, chloride, nitrate, and manganese. Elevated chlorides in the electrolyte have various negative effects including reduced current efficiency, increased handling costs at rod plants and smelters, increased anode corrosion, increased cobalt losses due to increased electrolyte bleed, degradation of HDPE piping, and increased corrosion in the SX/EW plants. Freeport-McMoRan Sierrita Hydromet is unique in that a high-chloride byproduct stream from the molybdenum process is pumped into the SX raffinate solution pond. This byproduct steam accounts for the majority of chloride introduced to the circuit, and over the years has built up to a point where 4000ppm chloride is consistently in the PLS feed to the SX. Concentrations of chloride over 70 ppm in electrolyte will result in downgraded cathode, so it is important to limit chloride carryover from SX as much as possible. Historically, Sierrita has been able to manage chloride levels with reactive techniques including increasing electrolyte bleeds and rectifier amps. Decreasing copper in PLS has made high amps harder to maintain, and increasing bleed rates have a direct impact on production goals."

Jan 1, 2015

By G. X. Du

Reaction kinetics of serpentine and hydrochloric acid is theoretical basis for optimizing reaction process conditions of serpentine and hydrochloric acid. Kinetics of serpentine and hydrochloric acid was studied in this paper. The results indicated that apparent reaction order to hydrochloric acid was two and reaction kinetic equation could be expressed as: 2HClHCl,ddtckct-=·. The diffusion rates of hydrogen ions in liquid film on surface of serpentine particle and in amorphous silica layer generated in the reaction and chemical reaction velocity during the reaction had important effects on to-tal reaction velocity. And chemical reaction velocity had the most significant influence. The relation of conversion rate of magnesia xMgO with reaction time could be expressed as: 1(1)xkt--=·.

Jan 1, 2014

By S. Goodman

Successful exploration for and exploitation of a mineral deposit requires an accurate understanding of the deposit architecture in 3D, and of the development of the mineralizing system through time, which requires a thorough comprehension of the structural framework of the deposit. The integration of geological, geophysical and geochemical datasets to arrive at a 4D structural framework is well-established and has been successfully applied by SRK Consulting in projects from deposit to regional scale. In some cases, we can go beyond this, applying the SEEBASETM technique, which utilizes a ?bottom-up? approach to basin analysis. SRK?s approach primarily relies on the interpretation of magnetic and gravity data, calibrated with many other datasets including mapped geology, topography, event histories, wells/drillholes and seismic data. The SEEBASETM model is a culmination of this data integration and is produced through an iterative process of structural interpretation and geophysical modeling, where an interpretation of basement composition and 4D structure is used to constrain depth-to-basement geophysical modeling, and the modeled depths are then used in conjunction with the structural interpretation to constrain contouring of the basement topography. The result is a rigorously calibrated, 3D view of the basement surface, which can be used to understand the basement and basin architecture, and thus serves as a predictive exploration model. This technique, which was developed for use in the petroleum industry, is now finding success as a predictive tool in mineral exploration.

May 1, 2003

By W. R. Bacon

"IntroductionTHIS IS a brief discussion of certain regional and economic aspects of the Coast Range of British Columbia. Between Portland canal and the 60th parallel of latitude, only the eastern margin of the Range is in Canada. The solely British Columbia interval extends from Portland canal to Burrard inlet. Personal observations in various parts of this area form the basis for much of this paper.Regional GeologyGranitic RocksSome of the best, most continuous exposures in the Coast Range are found at sea level. Reconnaissance study of the coastline has shown that the Range is predominantly granitic in character, but there simplicity ends, for the term 'granitic' as applied to the Coast Range covers a variety of mineralogical compositions. Actual granite is quite uncommon, occurring mainly in irregular or dyke-like masses that do not achieve batholithic dimensions. It is commonly pinkish, relatively homogeneous, and exhibits few of the deformational features that are obvious in much of this plutonic complex.Most of the granitic rocks of the Range fall well within the compositional limits of quartz diorite and granodiorite. The problem of resolving the great mass of these rocks into smaller coherent units is in general a difficult one. As noted above, granitic rock of uniform composition and texture is found in restricted areas and can be outlined without much difficulty. One such body occurs on the southern shore of Nelson island."

Jan 1, 1955

By Haizea Arratibel, Diana Méndez, Jhuliana Macas, Michelle Peñaherrera

La forma en la que las empresas ingresan a un territorio sienta las bases para las dinámicas de relacionamiento a futuro. El diálogo multiactor es una herramienta que permite, desde un inicio, formar relaciones de confianza y acción colectiva, pasando así de una dinámica transaccional a una transformacional. Esto alcanza resultados que van mucho más allá de la gestión de conflictos, enfocados a crear un territorio sostenible bajo un modelo de gobernanza sólido. Se presenta el caso del proceso de diálogo multiactor en Los Encuentros, Ecuador, bajo el marco del proyecto Fruta del Norte de Lundin Gold.

May 10, 2023

By Luiz Carlos Teixeira Brandão

O Alto-Forno 3 da Usiminas em Ipatinga, que atualmente está na sua quarta campanha, apresenta 30 ventaneiras. Nesta campanha houve alguns eventos de arrombamento e avermelhamento dos algaravizes. A causa destas ocorrências são obstruções das frentes de combustão das ventaneiras, gerando diversos transtornos operacionais. A fim de se evitar novos fatos semelhantes foram desenvolvidos alguns sistemas de monitoramento das frentes de combustão. Dentre os sistemas desenvolvidos se destacam o diferencial de pressão do conjunto de sopro; e, o controle da temperatura do conjunto de sopro. Os sistemas desenvolvidos permitiram maior confiabilidade nas ações imediatas dos operadores em anormalidades na zona de combustão com consequente ganho em desempenho operacional do alto-forno.

Aug 1, 2018