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By Bian Xue, Wu Wenyuan

In order to recycle the iron and rare earth from the Baotou tailings, a roasting method was developed involving the addition of C, Ca(OH)2, and NaOH, designed to both decompose the rare earth minerals and convert haematite into magnetite and allow its recovery. The effect of various parameters such as roasting temperature, roasting time, C addition, Ca(OH)2 addition, and NaOH addition on the reduction ratio of haematite (iron sesquioxide) and decomposition ratio of rare earth were investigated. The results showed that the reduction ratio of haematite and the decomposition ratio of rare earth could be as high as 85% and 95% respectively when the roasting temperature was 650°C, roasting time was 60 min, Ca(OH)2 addition was 4%, NaOH addition was 3%, and C addition was 1.5%.

Jan 1, 2014

By Karl J. C. Harries

"9.1. INTRODUCTIONIn Chapter 5 of Volume I royalties are dealt with and several topics would appear to be duplicated in this Volume. However, Volume I may be looked upon as a general guide, whereas this Volume is a reference volume. It deals in considerable detail with specific provisions and concepts relating to royalties between private parties. This does not, however, mean that Chapter 5 can be ignored. It should be looked upon as a source of general information concerning royalties between private parties and as a negotiating aid intended to give an overview of various topics. You may well find that in its general approach it will lead you to ask a question which, hopefully, will be dealt with in this Volume .It should be remembered that royalty agreements are agreements with a particular focus, and so the concepts set forth in Chapter 1 apply to them. This chapter addresses a few considerations specific to royalties that will usually form part of an agreement rather than a stand-alone agreement.9.2. FORMAT FOR ROYALTY PROVISIONSIn many of the cases where royalties arise, they are adjunct to, or part of, other arrangements. For example, a royalty may form part or all of the consideration to be given to an owner upon purchase of his property, or it may arise if a joint venturer ceases to contribute to the venture and has his interest converted to a royalty.1 It is with such situations that this section primarily deals; if the royalty is contained in an agreement that is singularly, or primarily, concerned with creating it, then it is just a normal agreement.Commonly, by the time the right to receive the royalty arises, at least some of the other provisions of the agreement have been performed and/or become redundant. For example, in an option agreement the royalty will be a continuing obligation of the optionee, usually arising only after the option has been exercised.2 In a joint venture agreement, a royalty will often arise where the interest of a non-participating venturer has been diluted and converted to a royalty, in which case the recipient will usually become a passive party, entitled only to his royalty, and most of the rights that he enjoyed as an active venturer will cease to be effective."

Jan 1, 2003

By T. Takahashi, K. Oyamada, Y. Miyata, T. Isoo

The carbonation reaction of steelmaking slag has been known for many years. However, the size of blocks manufactured from this by-product material has been limited due to the difficulty of achieving a uniform reaction throughout the block. Using newly developed conditions, large porous slag blocks (1.0 x 1.0 x 0.5 m) were produced by car¬bonation of steelmaking slag with the optimum amount of water and supplying CO2 deep into slag powder compacted in molds. The development of these blocks has great poten-tial to solve the problem of slag utilization, for example, by recycling slag in large car¬bonated blocks for artificial fish reefs and seaweed cultivation beds. This paper de¬scribes the carbonation reaction, the new process for producing large slag blocks, and the utilization of blocks in past and recent years.

Jan 1, 2004

By A. G. Beer

The evolution of microstructure is examined during the annealing of hot worked magnesium alloy AZ31. The influences of deformation and annealing conditions on the developed microstructures are assessed. It is found that annealing at a low temperature (300 °C), after deformation at a low temperature and strain rate (300 °C and 0.001 5-1 respectively), results in the development of abnormally large grains. With increasing values of Z (lower temperatures, higher strain rates), static recrystallization of the dynamically recrystallised structure takes place; smaller annealed grain sizes are attained and the time at which coarsening begins is reduced. Whilst both the deformation and annealing conditions influence the time it takes to reach a stable annealed microstructure, the grain size attained is governed solely by the prior deformation conditions employed.

Jan 1, 2006

By D. L. Babbitt, Sniezek

"This paper deals with the varions methods for the rapid Joading of unit trains which are being: used by ore procossors to move their product to dock-s1de storage facilities or their ultimate customer. Some of the techniques that have been used include (1) volumetrie loading, both in motion and static, (2) batch weighing into moving cars and (3) batch weighing into cars that have been stopped. Particular emphasis shall be placed on the two systems now in use at the Adams Mine facility of Jones and Laughlin Steel Corporation and at Cliffs of Canada's Sherman Mine. Typical ""turnaround"" times, loading rates, types of cars, weighing accuracies, material handling concepts and maintenance considerations shall be discussed."

Jan 1, 1969

By Jiachen Wang

Longwall top-coal caving mining is one of the major mining methods for extracting thick coal seams in China. The top-coal caving longwall mining was began to use in the 1980s in China, and got the rapid development. The development of the top-coal caving mining technology in China, the achievements and the theoretical aspects progress of this method are described in detail in this paper. And the main technical model of China's top-coal caving mining is introduced in this paper. This paper also introduces the application of large-cutting-height mining in China and the technical level it has reached.

Aug 1, 2013

By N. A. P. Kiran Kumar

The Zr-Nb alloys are reported to be showing superior resistance to corrosion and substantially lower hydrogen pickup when compared with zircaloys. In the present study zircaloy-4 and Zr-1Nb (E110) alloys were hydride using high pressure hydrogen gas furnace at a pressure of 20 MPa. Thermal cycling was done on the samples at a temperature of 3500C for 10 cycles with 5h soaking time at 3500C per each cycle. The Microstructural observations on zircaloy-4 samples show long and interlinked hydride like chain, oriented along the circumferential direction. Whereas in Zr-1Nb, short hydrides were observed with hydride platelets not showing interlinked chain like structure. The hydrides in Zr-1Nb were observed to be not showing particularly orientation along the circumferential directions. Electron backscatter diffraction was use to understand the hydride precipitation and their orientation in Zircaloy-4 and E110 alloy.

Aug 1, 2010

In 2009 Newmont Mining Corporation?s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Nov 1, 2011

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By Nelson Lawrence

An Electrical Risk Management/Inspection Program has been designed specifically for the mining sector in order to provide electrical code expertise and systemic gaps in electrical systems. Goals include improved safety and productivity, reduced injuries and help to enable businesses to better comply with the electrical codes and regulations that govern them. The Electrical Risk Management/Inspection Program is now recognized by some of the world?s largest mining organizations. Since June, 2001 these electrical safety advisory services have been available to underground and surface mine sites throughout Ontario and are now offered throughout Canada and around the globe. This program is also currently being applied to review new electrical installations for mine construction projects thus improving the safety and reliability of mine site electrical systems.

May 1, 2006

By Antonio Fontana

"Environmental problems encountered with the use of diesel equipment in underground mining operations are discussed. The concept and procedure o implementing the Health Effects Index equation as a means of quantitatively assessing an underground working environment is outlined and sample calculations are present ed. Advantages and disadvantages of utilizing this method are also discussed.IntroductionWith the introduction of diesel-powered mining equipment in the 1960s there arose several question s for the environmental engineer to consider. These included: 1. What are the constituents of diesel exhaust and how can they be detected and evaluated?2. What are the toxicities and long-term health effects of these constituents?3. What is the ventilating volume required to maintain the concentration of these constituents below toxic levels?Diesel engines are a class of reciprocating, internal combustion engines in which relatively high compression ratios are used to generate high air-charge temperatures, which cause ignition of fuel to occur spontaneously. Ideally, perfect combustion of the fuel would produce an exhaust consisting solely of nitrogen (N2), water (H2O), carbon dioxide (CO2) and oxygen (O2). However, because no combustion process is perfect, relatively small quantities of imperfect-combustion products, or pollutants, are also generated. These include hydrocarbons (HC), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), carbon (C) or soot, and sulphur dioxide (SO2).Currently, the Regulations for Mines and Mining Plants, made under the Occupational Health and Safety Act (Section 176), stipulate that weekly tests shall be made to determine the carbon monoxide (CO) concentration in the undiluted exhaust and at the operator's position, and the nitrogent dioxide (NO2) concentration at the operator's position. Also, the aldehyde (as HCHO) concentration in the atmosphere, at the operator's position, is to be measured at least every three months. Threshold limit values (TLVs) have been established for each of the three combustion products, and each is regarded as a separate entity. Consequently, this does not allow for consideration of interactions and possible synergistic effects between the various exhaust components."

Jan 1, 1982

By Peter Lighthall

What is an engineering firm?s role? ? The ideal situation is a life of mine service alliance with the owner ? Engineering firms are long term custodians of information ? Maintain consistency with established closure objectives, adjust closure plans to meet changing situations and technologies ? Develop range of solutions and present owners with risk profile The mine closure planning process ?new mines ? For metal mining, geochemistry is the issue ? The planning process: ?Sampling ?Waste characterization ?ARD prediction ?ARD control strategies ?Life of mine waste management planning ?Assessment of residual impacts ?Development of strategies for dealing with residual impacts ?Estimate closure costs ?One time decommissioning and reclamation costs ?Ongoing treatment/maintenance costs

May 1, 2006

By R. Stauber, B. Friedrich, S. Hilgendorf, G. Homm, C. Gellermann

Due to recent regulations limiting tolerated lead concentrations in copper alloys, new recycling strategies have to be considered. This study investigates the suitability of technical approaches in order to recycle leaded copper alloys exemplified by CuZn39Pb2 and produce an alloy in compliance with future lead regulations in the European Union. Three pyrometallurgical methods are considered to achieve this goal, namely vacuum distillation, intermetallic precipitation and fractional crystallisation. The impact of essential process parameters i.e. pressure, temperature, time, atmosphere and quantity of additives are identified using thermochemical and kinetic modelling. An experimental implementation reveals a general suitability of all three refining processes. However, the individual efficiency of the different methods strongly differs. Thus, a detailed assessment is carried out in order to provide an evaluation on the efficiencies of these methods from a technological, economical and environmental point of view. Taking a possible industrial realisation into account, the authors recommend the approach of vacuum distillation, although the energy demanded is comparatively high due to the enthalpy of evaporation for zinc, or rather, lead. However, required lead concentrations can be reached quickly without introducing an external element to the material. The prediction of selectivity and evaporation speed, which are immanent variables for a successful implementation, can be validated experimentally. INTRODUCTION In 2016 approximately 1 million tonnes of leaded copper alloy semi-finished goods with an average lead content of 2.1 Ma% have been produced in the European Union (EU). The global production in the same period exceeded 5.5 million tonnes, while the lead concentration has stayed constant at around 2.4 Ma% for the last 50 years. Up to 80 % of the current production volume is covered with end-of-life scraps, which are used for direct re-melting, depending on the alloy composition. Lead has been a popular alloying element in copper alloys in general, and in particular in brass due to its positive impact on various mechanical, physical and chemical properties, especially machinability. Health and environmental concerns were drivers for many governments to implement limitations on lead. In order to further utilise the resource potential of leaded copper scrap, it is inevitable to develop methods to efficiently eliminate lead from circulation as far as possible. (Glöser, Soulier, & Tercero Espinoza, 2013; Soulier, Glöser-Chahoud, Goldmann & Tercero Espinoza, 2018)

Jan 1, 2019

By T. Thriveni, Ji Whan Ahn

"The current advanced technologies for the manufacture of light weight metals processing significantly increasing and attributes to the safety, performance, recyclability and economy. Still lack of technologies developed for light weight metals processing waste utilization and application. Environmentally friendly methods need to develop for better understanding the processing waste utilization. Alumina and aluminium processing creates a wide range of waste products, the most significant being is red mud. Bauxite residue is a high volume hazardous waste and nearly 3 billion tons have been dumped worldwide. Approximately, 120 Million tons/yr of red mud being produced without any environmental sustainable solution. Currently the most significant technology is waste utilization. The bauxite residue is suitable for road base construction, golf bunker sand, back fill and, general fill. Sustainable recycling technologies are necessary for the bauxite residue utilization for the recovery of rare earth elements and cement materials. Carbonation or CO2 sequestration of carbon dioxide is a method pioneered for the bauxite residue is modified to reduce alkalinity. The carbonation of alkaline material is an inexpensive and safe process that leads to the formation of thermodynamically stable products. The use of the carbonation can be an advantageous solution for environmental climate change and sustainability problems in the new century.INTRODUCTIONIn 2014, bauxite consumption was estimated to be 9.6 million tons, nearly all of which was imported, worth an estimated 269 million dollars. More than 95% of the bauxite was converted to alumina, and the remaining 5% went to non-metallurgical products, such as abrasives, chemicals, proppants, and refractories. Global aluminum demand is growing steadily spurred by growth in India and China (RBCAluminum Market Outlook, 2013) (Figure 1). Aluminum consumption is expected to rise 5% annually through the end of the decade, reaching 67 million tons per year by 2020. Global bauxite production decreased by 17% from that of 2013, principally owing to lower production in Indonesia. In response to a Government ban on exporting bauxite and other unprocessed mineral ores that took effect on January 12, 2014, bauxite mines throughout Indonesia shut down and production decreased from 55.7 million tons in 2013 to an estimated 500,000 tons in 2014. The ban was part of a mining law that was instituted in 2009 to increase development of downstream processing facilities in Indonesia."

Jan 1, 2016

By A. Malfliet, A. Van den Bulck, D. Willems, M. Guo

The feed stock of copper fire refining processes consists of two major constituents: blister copper and high-Cu secondary scrap. A large fraction of this secondary scrap, originating from urban mining, is quite high in impurities such as Fe, Ni, Pb and Sn. Problems arise in electro-refining when these elements exceed certain limits. As a consequence, transformation of the secondary copper raw materials into high grade copper has become troublesome. However, the behavior of impurities relevant to fire refining conditions, essential for anode refineries, has not been studied in detail. Furthermore, limited research has been performed on the distribution of Ni between copper metal and slag. In this study, equilibration at 1300°C of liquid Cu-1wt.% Ni alloy and CaO-CuOx- FeOy-SiO2 slag in vacuum sealed quartz ampoules was performed for 12 hours, followed by water quenching. Electron Probe X-ray Microanalysis was employed to investigate the composition of the equilibrated alloy and slag. The distribution coefficients of Ni between slag and alloy were determined as a function of oxygen partial pressure and CaO concentration. INTRODUCTION Europe’s initiatives for a circular economy, pushing for resource-efficient ways for a sustainable future, puts Europe at the forefront of the globe. In Europe, 50% of the copper originates from recycling, being an excellent example of Europe’s circular economy (Juncker, 2018; Lacasse, 2018). High-grade copper recyclates are made available which regularly contain impurities like Fe, Ni, Sn and Pb. Aurubis Belgium is responsible for recycling these types of recyclates to anodes, cathodes and copper products. However, after fire refining of copper, the aforementioned impurities remain in the anode copper, leading to problems in electrorefining. During the fire refining of copper, a CaO-“Cu2O”-“Fe2O3”-SiO2 slag is used. Fundamental information of the distribution of impurities between the copper and this slag system is therefore essential to understand and improve the copper fire refining process at Aurubis Belgium.

Jan 1, 2019

By S. Amira

In the last two decades, many new creep-resistant magnesium alloys have been developed for high temperatures applications. Their mechanical performance and corrosion behaviour were reported for various experimental conditions. However, these conditions often led to uneven comparison basis. In the present study the microstructure, mechanical properties and corrosion performance of four of these newly developed creep-resistant magnesium alloys were systematically compared. Specimens were obtained from experimental box-like components that were die-cast and thixocast in comparable conditions. Their mechanical and corrosion properties were compared using similar testing conditions. Results show that the creep resistance, strength and impact resistance of specimens are comparable but systematically lower compared to specimens cast under optimized conditions. The reduced concentration of elements such as Al, Ca, Sr and Ce lead to a decrease of the corrosion resistance of the magnesium alloys in 3.5% NaCI solution.

Jan 1, 2007

By M. Huang

Electrodeless conductivity was employed to investigate the feasibility of continuous on-line monitoring of the free acidity of sulphate and/or chloride solutions of Cu and other base metals from various hydrometallurgical processes. These solutions were measured with both commercial and experimental electrodeless conductivity sensors from 15 to 250°C. It was confirmed that hydrogen ion has the greatest impact on conductivity by carrying the bulk of the current because it is the most mobile ion. In combination with a solution speciation analysis the conductivity sensor can be calibrated to account for the contribution of Cu electrolytes as well other dissolved salts allowing fast and accurate on-line measurement of free acid. The sensor was tested at both lab and pilot scale with very good performance. The average difference between the measured and the titrated acid concentration was less than 5%, which is excellent for industrial applications.

Jan 1, 2007

By R. Butar-Butar, J. Mosher, G. Banini, J. Hollow, A. Villanueva

The effect of High Pressure Grinding Rolls (HPGR), as a preceding stage to a conventional ball mill circuit at PT Freeport Indonesia’s C1/C2 concentrators, has been studied in terms of downstream grinding efficiency and circuit performance. When milling the product from the HPGR, mill capacity increased by 21% for the same product grind size, when compared to processing similar ore from a conventional crushing circuit. This achievement is a result of several reasons, among them: reduction in feed size (F80), fines generation beyond the proportional reduction in F80, reduction in ore hardness induced by HPGR comminution mechanism, optimization of the recycle system of the HPGR and ball string optimization in the ball mill circuit given the new feed to the mill.

Jan 1, 2012

By C. M. Trigg

"PEC uranium deposit, 100 km southwest of Coppermine, was discovered by diamond drilling in 1976 following ground and airborne geophysical surveys, geological mapping, geochemical surveys and boulder prospecting that were initiated as the result of the discovery of uraniferous sandstone outcrops in 1969 by geologists of Aquitaine Company of Canada Ltd.The deposit is within gently northeasterly dipping medium to coarse-grained Unit 11 quartzitic sandstone of Neohelikian Dismal Lakes Group. The deposit is from 10 m to 70 m above the base of the sandstone which, beneath the deposit, non-conformably overlies weathered and altered Aphebian granite of Great Bear Batholith or unconformably overlies rubble breccia, conglomerate and medium-grained Unit 8 sandstone of Paleohelikian Hornby Bay Group.A northeasterly trending, 500 m wide graben, bounded by the steeply dipping northeasterly striking Imperial and Aquitaine faults, contains the deposit which is 1.1 km long by up to 340 m wide. The deposit overlies a post-Hornby Bay Group, pre-Dismal Lakes Group topographic high. Uranium principally occurs as stratabound, often peneconcordant bands; a lesser amount of uranium is fracture controlled.Stratabound uranium exists in gently easterly dipping, subparallel bands ranging in thickness from 1.5 m to 6.0 m. Pitchblende, coffinite and sooty black uranium oxides occur as interstitial disseminations and grain coatings subparallel to bedding; they also replace pyrite and form narrow veinlets.Small amounts of torbernite, carnotite and cuprosklodowskite coat pitchblende and are disseminated within mineralized bands. Pyrite, marcasite, chalcopyrite, chalcocite, cove/lite, digenite, azurite, malachite, arsenopyrite, glaucodot, niccolite, bravoite (? ), goethite, hematite and magnetite as well as quartz, barite, calcite, biotite, chlorite and clay minerals exist within the mineralized bands. Uranium grades of 0.1 % to 0.3 % U3O8 over thicknesses of 1 m to 2 m are typical.A steeply dipping fracture zone near the Imperial fault contains sooty black uranium oxides, torbernite, carnotite and cuprosklowdowskite as well as sulphides, cobalt arsenides, quartz and carbonate. The zone may reach 70 m long; its true width is about 1.9 m. Uranium grades range up to 5.18% up, over0.9m.Pitchblende and coffinite from PEC deposit have been dated at 1.08 ± .10 Ga with possible remobilization at .45 Ga. The deposit contains an inferred 3,150 tonnes of U3O8."

Jan 1, 1986