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By K. A. Natarajan, M. N. Chandraprabha

Selective separation of minerals from complex sulphide ores is a challenging task and it is often difficult to get commercially acceptable individual concentrates by conventional selective flotation using inorganic collector reagents. Microbially-induced mineral beneficiation has proved to be more effective, economically viable and an environmentally benign process for the effective separation of various minerals. Applications of microbially-induced mineral beneficiation are demonstrated in this paper with respect to beneficiation of complex multimetal sulfides. The role of adapted microorganisms and bioreagents in the beneficiation of complex sulphide minerals are also illustrated.

Jan 1, 2009

By T. R. Chari

The safe-level dilution of low-level radioactive wastes in large volumes of selected granular material is proposed as an alternative method of permanent waste disposal to current Canadian practice of concentration and encapsulation. Accepting the fact that a "background level" of radioactivity exists throughout the world, the authors feel that the concept of controlled dilution of radioactive wastes to a level in keeping with "background" is a plausible alternative to current thinking on the subject and is worthy of equal consideration.

Jan 1, 1979

By E. Viljamaa

In this research, earlier developed information integration method and novel web technologies are applied to intensify infrastructure construction process control. The applied method uses semantic methods to integrate scattered information that is later on exploited by process management using state-of-the-art web technologies. The applied method and web technologies not only improve the process management situation awareness by integrated up-todate multi-source process data but also provide platform independent access and visualization tool for process data. Utilization of such technologies potentially lead on cost savings, make processes safer and also more environmentally friendly. The integration method also enables intelligent queries to the integrated data making possible to use machine based inferring to the data.

Aug 1, 2013

By L. Cheng, Y. W. Pan, Y. R. Liu

"Impounding deformation of slope and foundation is significant during and post dam construction. Reservoir impoundment is accompanied with various phenomena, including material degradation, effective stress decreasing and buoyancy in rock masses. These phenomena are related with some engineering concerns like reservoir-induced earthquake, landslide and dam stability. The Malpasset dam and Vajont dam are typical hydraulic projects suffering from seepage in dam foundation and slope, which finally led to failure and landslide. Pore pressure in jointed rock masses is considered in constitutive relation. The expression of effective stress for porous rock with fluids is incorporated into the Drucker-Prager criterion. Based on monitoring data of valley width and dam deformation, the effective stress law is applied to analyse the impounding influence of slope and foundation to Jinping-I high arch dam. The dam is accompanied with complicated topographical and geological conditions. The results show that calculated and monitored values agree well, and the application of effective stress law provides an approach to evaluate dam deformation, stress and stability with impounding effect considered.INTRODUCTIONImpounding deformation of slope and foundation is a common and significant problem during dam construction and operation. This phenomenon exists in a lot of reservoirs in China, like Laxiwa, Ertan, Xiluodu and Jinping-I arch dams, and some dams in Europe. It is related with some engineering concerns like reservoir-induced earthquake, landslide and dam stability. The Malpasset dam and Vajont dam are typical hydraulic projects suffering from seepage in dam foundation and slope. Monitored data indicates that the valley width tends to shrink in hydraulic engineering during the impounding process, which will change the stress and deformation of dam and abutment. Therefore, global stability of dam and foundation should be evaluated with impounding process taken into consideration."

Jan 1, 2015

By Phillip J. Mackey, Susumu Okabe

Copper mining and smelting has been carried out in Japan for over 13 centuries and in fact stretching back into antiquity. In 1889, the first electrolytic copper refinery in Japan based on Elkington’s principles was started by Furukawa Mining at Honjyo in downtown Tokyo based on the multiple or parallel system. Within two decades, a number of other copper refineries had begun operation. Interestingly, but perhaps not surprising given Japan’s long history of copper production, this first refinery in Japan commenced just ten years after the first refinery in the USA (1879), and not long after the first plants in Europe. By 1935, as a result of growth in copper demand, there were six domestic copper electro-refineries in Japan with an installed capacity of 97,800 tonnes/a, while actual production was 71,200 tonnes/a. Since about 1932, the majority of these plants were based on the more common parallel or multiple system. In 1946, just after World War II, domestic production capacity had dropped considerably to 29,000 tonnes/a, however with reconstruction, capacity and production expanded rapidly, with production reaching 81,000 tonnes/a in 1955, 187,000 tonnes/a in 1960 and 307,000 tonnes/a in 1965. The introduction of the first refinery and the early ones that followed and subsequent developments are discussed in this paper. The major technical achievements during the high growth period from 1945 to 1963 included: the use of fire- refined anodes; the introduction of newly-developed rectifiers; the introduction of lead-lined or vinyl-lined concrete cells; improvements in the electrolyte heating system; application of improved anti-corrosion materials and the introduction of heat-insulating surface coverings. In 2018, Japan’s refined copper production totaled 1,595,000 tonnes of copper, with Japan ranking third in the world after China and Chile. INTRODUCTION In 2018, Japan’s refined copper production totalled 1,595,000 tonnes of copper and Japan ranked third in the world for refined copper after China and Chile (Wood Mackenzie, 2019). There are now eight copper refineries in Japan which provide Japan’s production of refined copper. These plants are listed in Table 1 (Wood Mackenzie, 2019), also showing the production trend since 2013; in general, production over this period has been relatively steady. The Toyo plant is now the 7th largest copper refinery in the world after several large plants as rated by capacity in China, Russia and India (ICSG, 2019).

Jan 1, 2019

By P. Leo

The hot deformation behavior of a Mg-9A1-1Zn alloy produced by high pressure die casting has been investigated by means of compression tests in the temperature and strain rate ranges of 125-300°C and 10-5-10-1 s-1 and torsion tests over 150-450°C and 5, 0.5, 0.05 5-1 . The compression samples were deformed in the die-cast state or after homogenization at 415°C for 2 h to evaluate improvements. A premature fracture at 45° with respect to the compression axis was observed in samples strained at low temperatures and high strain rates. The torsion specimens were tested as received or after a predeformation-homogenization treatment. In addition to constitutive analyses suitable for modeling previously published, the results are fitted to a relationship between strain rate normalized by diffusion coefficient and flow stress normalized by modulus. The results fit well with a set of published creep experiments that were conducted in the range of 70-150°C.

Jan 1, 2006

By Z. Luo, China University of Mining & Technology, C. Duan

"The magnetic separation removal rate of pyrite could be improved effectively by increasing the susceptibility of pyrite. The electromagnetic characteristics and absorption response performance of high-sulfur fine coal were studied in strengthening the susceptibility of pyrite. In the process of treating the sample through the microwave, electromagnetic energy could be converted into heat energy due to dielectric loss and magnetic loss. The RL(dB) was evaluate the performance of absorption response of coal. The microwave improved the susceptibility was in ultra-high frequency region, which is the most natural resonance. The absorption fine coal to microwave was strengthened and microwave energy was improved by adding the magnetite powder with double loss characteristics as the microwave absorber. The dielectric properties and permeability characteristics of the fine coal trend were investigated by maxing magnetite powder. The microwave absorption in different coal thickness was surveyed through the reflection of energy loss.INTRODUCTIONMicrowave desulfurization is one of the most important research directions (Haque, 1999; Makul, Rattanadecho, & Agrawal, 2014; Su, Tang, Zhang, Jing, & Bai, 2014). The working principle of microwave absorption response can be briefly described as the interaction of the sample with microwave energy, which will result in the microwave energy converting into heat energy loss (Keangin & Rattanadecho, 2013). For specific samples, the polarization effect includes multiple polarization mechanisms(Meikap, Purohit, & Mahadevan, 2005). Different polarization mechanisms have different occurrence time and dominant mechanisms. Meantime, energy consumption will be occurred during the process of polarization effect (Chelgani & Jorjani, 2011; Rowson & Rice, 1990) . The absorption of microwave energy in the fine coal is a process of electromagnetic response (Znamenácková, Lovás, Mockovciaková, Jakabský, & Briancin, 2005). Microwave transfers the electromagnetic waves into the heat energy by microwave dielectric loss and magnetic loss for achieving the absorption of microwave energy in the treatment of samples (Lee, Kim, Kim, Chung, & Kim, 2004). The additive magnetic medium is Fe3O4 belonging to microwave energy absorber of double loss medium (Uslu, Atalay, & Arol, 2003)."

Jan 1, 2016

By V. G. c Papangelakis, M. Huang

A conductivity cell, developed previously, was employed in an effort to investigate the inter-relation between electrical conductivity and acidity of sulphuric acid - metal sulphate solutions at high temperatures. The measured solutions include the H2SO4-H2O, MgSO4-H2O, H2SO4-MgSO4-H2O, H2SO4-MgSO4-Al2(SO4)3-H2O solutions. All solutions reported in this paper were measured from 15 to 250 °C at equilibrium vapour pressure. The maximum measured concentrations of H2SO4, MgSO4 and Al2(SO4)3 were 0.45 m, 0.30 m and 0.10 m, respectively. It was found that, from 15 to 250°C, there is a linear relationship between H2SO4 concentration and electrical conductivities for acid concentration up to 0.45 m. At 250 °C and constant H2SO4 concentration, the solution conductivity drops with the increase of MgSO4 concentration. Lt is suggested that this drop is caused by a decrease in the concentration of H. Finally, an empirical model was developed based on the available measurements. This model has been tested against real laterite leach solutions where sulphuric acid and metal sulphates are dominant electrolytes. The average difference between the estimate acid concentration from this model and the one from titration was less than 5%.

Jan 1, 2004

By M. H. Colebrook

Nickel laterites contain about 70% of all continental or terrestrial nickel resources; therefore the recovery of nickel from lateritic ores has large economic significance. The processing of lateritic ores involves the preparation and movement of concentrated aqueous suspensions. However due to complex characteristics and non-Newtonian properties, ranging from shear-thinning to shear-thickening and from thixotropic to rheopectic, a basic understanding of the flow behaviour must be developed. This understanding will assist in the development of new plants and the operation of existing plants. The work in this paper involves the characterization of three ore types from the Vermelho ore deposit to categorize them as rheologically simple to complex. Rheological testing was also conducted on pure mineral samples that represent the main minerals in these samples. The results show that the rheological properties of the ore types can be related to the surface properties and physical characteristics of the main mineral constituents.

Jan 1, 2006

By Brian W. Mackenzie

The paper addresses five questions concerning the economic of gold exploration in the western Canadian shield. Can historical footprints be used to project future gold prices for exploration planning? Experience suggests that gold price forecast are too clo ely tied to current market events to provide meaningful guidelines. What range of breakeven gold price will typically be required to ju tify gold exploration in Canada? Minimum price requirements. initially asses ed at $540 to $1080 per ounce, probably lie in the range of $480 to $760 per ounce (expressed in 1985 Canadian dollar). Within Canada, what role do regional conditions and taxation policies play in determining the viability of prospective gold exploration targets? Striking interprovincial differences are found to exist, given the same geological circum tance -Nova Scotia, ew Brunswick, and Quebec rank towards the top in term of motivating exploration, Briti h Columbia provides the least investment incentive, while Saskatchewan and Manitoba place around the middle of the Canadian league. How can minimum acceptable tonnage-grade conditions for gold targets in the western shield be established and, then, constructively applied to provide exploration planning guidelines? Minimum target conditions, realis tically defined in terms of a broad band of doubt, can be used judiciously to help balance the direct costs of uneconomic exploration with the opportunity costs associated with rejecting economic deposits. How does the average cost per ounce of gold discovered in the western shield compare with the overall Canadian experience? Average discovery costs for the we tern shield, apprai ed at $100 per ounce, are shown to compare favourably with the Canada-wide record.

Jan 1, 1986

By J. J. Quinn

Several mineral flotation plants utilize process water with high soluble salt content. The processing of semi-soluble minerals, the use of recycle streams, sea or well water give rise to this situation. It is unclear as to the overall effect on flotation response though there does seem to be evidence of bubble size reduction, increased froth stability and reduced reagent dosage. The present work aims to quantify the effects of salts present in process water on gas dispersion (bubble size and gas holdup) and froth properties. The salts examined were NaCI, CaCl2, Na2SO4, Na2S2O3 and Al2(SO4)3. Tests were conducted to determine the effects of salt type and concentration on gas holdup and bubble size distribution. The salts containing multivalent ions had a greater impact than the monovalent ions, in keeping with the literature. A relationship between gas holdup and ionic strength was established. The concentration of frother (methyl isobutyl carbinol, MIBC) giving equivalent gas holdup was determined. The effect of salt and frother combinations was also explored.Proposed mechanisms for coalescence inhibition in salt solutions are briefly reviewed in light of the current findings.

Jan 1, 2006

By Jr. Fackler

The ionization potentials of gaseous Group 11elements are similar, with Au(0) being 1.5 eV greater than the next highest member of the group, Cu(0). The ionization potentials are all very much greater than the alkali metals, making these ?coinage? elements rather unreactive to chemical oxidation. Ionization from the first oxidation state shows a different pattern, with Ag(I) being the most difficult of the Group 11 ions to lose an electron. Gold(I) is noble and only normally oxidized in the presence of strongly coordinating ligands such as thiols or cyanide. Gold(I) compounds are 2-, 3- and 4- coordinate, with 3-coordinate species generally showing visible photoluminescence under UV excitation. Dinuclear Au(I) compounds with strongly coordinating S or C ligands can be oxidized to form isolable metal-metal bonded Au(II) compounds which are often readily isolable. Many have been structurally characterized. T he ease with which electrons are lost from closed shell dinuclear sp ecies (with anti-bonding M-M interactions) increases when metalmetal bonded compounds are formed. T his observation was made by our group with oxidative-addition studies of dinuclear gold(I) ylide complexes. It was superbly demonstrated recently by Cotton?s group who reported the isolation and characterization of a dinuclear closed shell transition metal species which is more readily oxidized than cesium. Trinuclear Au(I) pyrazolates, TR(pz), carb eniates, TR(carb), and benzylimidazolates, TR(bz), are well known and undergo electron loss through oxidative addition forming Au(I,III) mixed valence species and ultimately trinuclear Au(III) species. Au(II) species are absent from isolation in these oxidations. These carbeniates and benzylimidazolates also are excellent bases for metals ions such as Tl(I) and Ag(I). The acidic, neutral trinuclear compound [Hg(C6F4)3]3 also interacts with these bases. We have also shown that the neutral organic pi acids C6F6 and TCNQ form stacked pi-acid pi-base products with the trinuclear Au(I) compounds. In this paper, the structure of the octafluoronaphthalene acid-base product will be described. It displays a feature not observed previously in that the product is photoluminescent with a bright yellow emission. The 3.5 ms lifetime is very long and reminiscent of the long lifetimes observed by Balch for the stacked methyl,methoxy Au(carb). The electrochemical oxidation of tetragold(I) clusters, [Au4(form)4] have been studied in 0.1 M Bu4NPF6/CH2Cl2 at Pt working electrode at different scan rates. Three waves are obtained at 0.75, 0.95, and 1.09 V vs Ag/AgCl at scan rate 500 mV/s. The potential of the three reversible waves is independent of the scan rate in the range 50 mV/s to 3 V/s. The current at the third wave is larger than those at the first two waves. These tetranuclear species app ear to be effec tive catalyst precursors for the oxidation in air of CO. Introduction. The electronic structural relationships of the coinage elements and the alkali metals are similar in the sense that each have a [closed shell]ns1 configuration, yet their ionization energies (Table) and chemistries are clearly vastly different. The Group 11coinage elements have an underlying nd10 level immediately below the ns1 level. Unlike the alkali elements, ionization leaves the filled d electron shell the next accessible for further ionization. The coinage elements are all relatively ?noble?, much less reactive to environm ental conditions than the alkali metals. With the coinage elements, oxidation becomes very much dependent upon the types of ligand s availab le to bo nd to the ionized state.

Oct 1, 2003

By Steve Custer, Chris Bennett, Patrick Garretson, Glenn Dobby, Jacques McMullen

"Barrick Gold is in the process of expanding one of its grinding circuits at the Goldstrike property as a response to both increasing ore hardness and increased ore sensitivity to finer grinding as it relates to gold recovery. The plant currently operates with two parallel grinding lines, each with a SAG mill, a pebble crusher, and a ball milling arrangement. As part of determining what additional equipment was to be required, a CEET evaluation program was conducted (CEET is an acronym for Comminution Economic Evaluation Tool). The work included: Development of a hardness ‘model’ for the ore body, as described by SAG Power Index and Bond Work Index;Site benchmarking surveys to fine tune the SAG and ball mill calibrations within CEET;Conducting CEET studies to examine the process options;Comparing CEET results to standard grinding circuit design techniques.The recommendation of the study, presently being implemented, is the installation of an additional ball mill on one of the two grinding lines. This paper reviews the sizing techniques applied, providing a CEET case study for circuit performance analysis and circuit design. OVERVIEW OF COMMINUTION AT GOLDSTRIKEOre feeding the autoclaves at Goldstrike are first processed through two parallel grinding lines. Both lines use SAG mills with cone crushing of pebbles followed by ball milling. A summary of the key circuit parameters is provided in Table 1. Line 1 primarily processes underground Meikle ore, although when no Meikle ore is available, it processes open pit Betze ore. Line 2 processes Betze ore exclusively. The Mill Line 1 P80 objective for Meikle ore is 74 microns. According to the recovery optimization analysis, a P80 of 90 microns was recommended for Betze ore. The potential however exists to perform co-mingling of both ore types and feed the higher grade Betze ore to Line 1, in which case the P80 of 74 microns would be retained."

Jan 1, 2001

By Robert B. Parsons

"Effective January 1, 1990, mines in British Columbia are subject to a new provincial mining tax statute, the Mineral Tax Act. Under this Act, mines are subject to a two-tier tax system, with a minimum tax payable on ""net current proceeds"" and a higher tax paid on net income. For many mines, the present value of tax paid under the new rules should be comparable to the amount paid under the old rules. Earlier cash payments could pose difficulties, particularly for smaller mines, but existing producing mines could benefit in the short-term.IntroductionEffective January 1, 1990, British Columbia has replaced the provincial mining tax regime under the Mineral Resources Tax Act with a new system under the Mineral Tax Act. The new rules borrow some ideas from other provinces (New Brunswick's two-tier concept, and Saskatchewan's indexed costs) with a view to levying a tax that is fairer to both the producer and the province."

Jan 1, 1990

By McNeely DuBose

INTRODUCTORY PROSPECTING for aluminum has always been, and still is, a peculiar combination of the technical with the physical approach, and 1 want to explain my conception of the term 'prospecting' when applied to aluminum, which differs in some respects from the ordinarily accepted idea of prospecting. In the early days of gold mining, prospecting was a search in the hills and the river beds for the metal, not for its chemical combinations. And so it was in the early days of aluminum, with the difference that the search for the metal was carried on, not in the hills and dales, but in chemical laboratories. Aluminum is never found in the elemental state and at that time the metal bad never been seen, but scientists of that day bad forecast that such a metal must exist and in 1807 Sir Humphrey Davy went so far as to give this unseen metal a name, aluminum, from the Greek word alumen. This word applies to our alum, and it was from alum that Davy sought to produce the metal. It is strange to think that, in laboratories throughout England and on the continent, prospecting for aluminum was busily under way by men who had never seen the metal they were searching for. Their situation was something like that of the fisherman and the 'big one' that got away. They could describe the metal, give its exact weight, and even name it, but they could not produce visual evidence of its existence. Eventually, however, the efforts of the scientist 'prospectors' were rewarded and in 1826 the metal was actually produced, possibly first by Wohler, though Oerstedt, a Danish chemist, is usually credited with the achievement.

Jan 1, 1951

By D. A. Beattie

Three novel dextrin polymers of varying functional group chemistry but similar molecular weight have been used to depress talc in single and mixed mineral studies. The mixed mineral system was a model sulphide ore consisting of talc, pentlandite, and chalcopyrite. Adsorption isotherms for the three polymers on both valuable and gangue mineral phases were determined to give initial clues as to the ability of the polymers to depress talc. Flotation testing revealed a distinct hierarchy of effectiveness of the polymers in the depression of talc in the single mineral system (MP Dextrin > CM Dextrin > Dextrin TYM), reflecting the observed adsorption affinity and adsorbed amount of the polymers on talc. However, a different order of effectiveness was observed for talc depression in the mixed mineral system (CM Dextrin > MP Dextrin > Dextrin TYM). Competition between the valuable and gangue mineral phases for uptake of MP Dextrin is responsible for its observed decrease in efficiency in mixed mineral flotation. All three polymers were found to be reasonably selective in their action, although at high dosages the polymers began to affect the flotation of the valuable minerals.

Jan 1, 2006

By G. C. Nowlan, A. Illis, H. J. Koehler

At its iron ore recovery plant at Copper Cliff, INCO produces about 17 million pounds per year of a pure, acid-soluble, dense nickel oxide from nickeliferous pyrrhotite. The process used is also applicable to a broad range of ammoniacal nickel-bearing streams. The product has been widely accepted by the chemical, ceramic and electronic industries.

Jan 1, 1970

By A. Himsley

This paper presents a review of the existing ion exchange resin systems for treating unclarified pregnant liquor, with particular reference to uranium extraction. A new concept of a truly continuous ion exchange system is described and operating details are given,of a 0.6.-m (24 in.) diameter pilot plant treating unclarified acid leach liquor.

Jan 1, 1977

By Farnham. G. S.

It is difficult co know how to deal with this subject before a group having such mixed interests. The mining man is not coo concerned with the problems of alloy research. The engineer is more interested in properties of materials than how these properties can be achieved. The business man feels that scientific history and prognostication are not for him, predicting trends or possible developments in the economic field being a more than sufficient occupation. Yet the application of physical metallurgy research to industry is of importance to miner, engineer, and business man, for only through such application can the continuing existence of industries manufacturing or consuming metals be assured. History shows that hard work does not guarantee industrial survival. For instance, the Bessemer method of steel making superseded puddling operations; it, in its turn, has been largely displaced by open-hearth processing; later, steels made in electric-arc furnaces displaced open-hearth products in the quality field; and now, very specialized steels are being made in high-frequency rather than in arc furnaces. It is apparent then, if industry is co remain healthy, complacency must give way co imaginative planning, based on a thorough knowledge of production technique, a knowledge supplied by efficient research.

Jan 1, 1947

By Sang-Kyun Woo

The electric power conduit (EPC) in Korea has been constructed since 1978. Facing the challenge of safety and sustainability of the EPC, it is urgent to develop an inspection strategy and maintenance system for the structure based on the concept of life-cycle management. This paper introduces the newly developed mobile inspection and diagnostic system of the EPC. The novel aspect of this particular system is the integration of non-destructive mobile inspection techniques with BIM (Building Information Modeling) and LBS (Location-Based Service). BIM is an ideal tool and platform for developing an inspection and diagnostic system, and RFID (Radio Frequency Identification) is a useful tool to construct USN (Ubiquitous Sensor Network) for LBS. The goal of this research is to establish an EPC inspection and diagnostic system concept based on BIM and LBS using RFID. In this research, a BIM model of OPENTBM tunnel for EPC will be established to show the integration of 3D CAD with the inspection data. An EPC?s maintenance database, which includes the deterioration types of the structure, inspection records, and repair methods, was designed to interact with the BIM. The system will be implemented by the BIM with the related database, in which the construction geometry and all related information are stored. The proposed system was designed to utilize the inspection and diagnostic system under the USN environment using RFID in EPC directly.

Aug 1, 2013