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By P. R. A. Andrews

"Areas of bubble contact were delineated for cassiterite in the presence of chloride, fluoride, sulphate, phosphate, oxalate and citrate ions using dodecylamine hydrochloride collector. The limits of pH, and the minimum collector concentration were established using the bubble pick-up technique.Bubble contact did not occur below the p.z.c. (point of zero charge), estimated to be 4.7, in the presence of chloride ion, and fluoride ion showed only a weak response in the same pH range. These anions are considered to act as indifferent electrolytes. Activation at pH values below the p.z.c. was obtained with sulphate, phosphate, oxalate and citrate ions; the greatest response was by oxalate and phosphate ions extending pick-up to between pH 2.0 and 2.5.Activation appeared to be strongest when anionic protonated species were in maximum concentration. Strong activation also corresponded to the formation of very stable metal ion species, thought to be formed on the surface of cassiterite, between exposed stannic ions and modifying anions; dodecylammonium ions being absorbed on the surface so modified."

Jan 1, 1991

By Marketa D. Evans

The mining industry has a significant opportunity to capitalize on its past learnings in order to build better social relationships. The industry?s relationship with society is both critical and under pressure. Rising levels of public opposition and social conflict are already having material impacts on operations around the world. Industry has an opportunity to shape the future direction of this social engagement, build public trust and proactively respond to a material risk to operations, but first it needs to better understand the nature of the challenges and the urgency of addressing them.

Aug 1, 2013

By Cesar A. Urbano Jr., Gretchen T. Lapidus

A series of experiments examined silver extraction from a high-grade sulfide concentrate employing thiourea solution. Thiourea was initially oxidized with hydrogen peroxide (H2O2) to form formamidine disulfide (FADS) and used to extract silver from the as-received concentrate and after various pretreatments. Very low recoveries (~30%) were obtained with the as-received concentrate due to competitive cementation reactions by metallic iron and easily oxidizable copper phases. Over 80% Ag recovery was obtained when the concentrate was pretreated to remove this iron and copper. The results suggest that an oxidative acid pretreatment of this concentrates significantly improves silver recovery upon leaching with thiourea.

Jan 1, 2014

By S. N. Rossovsky

"A new method for the hydrometalfurgical treatment of refractory gold arsenosulphide concentrates is presented. Themethod involves a combination of' finegrinding, intensive agitation, flotation, and cyanidation, and consists of leaching of -10u pyrite and arsenopyrite particles in alkaline solution under intensive agitation without the application of costly high-pressure and roasting techniques. Consistent extractions of gold, in excess of 96%, are achieved.IntroductionConventional methods of alkaline leaching of gold arsenosulphide concentrates in an autoclave» and under electrochemical oxidation( 2) require expensive equipment as well as high-cost energy and reagents. In other cases, processing of gold concentrates inelude: ultra-fme grinding, calcination at 200°C to 250°C with the addition of an oxidant (NH4NOJ followed by alkaline leaching of the resulting calcine with hydrogen peroxide, the latter being a complicated method yielding poor extractions of gold (89% to 90%). In this paper, a hydrometallurgical method is described for processing refractory gold arsenosulphide concentrates in which alkaline leaching is followed by cyanidation of the residue."

Jan 1, 1993

By S. A. Pence, A. I. McCallum, V. de Korompay

"Special salt protection rings containing a water-swell• able, polymeric sealant are in successful operation in Canadian potash shafts. Installed above the Prairie Evaporite salt formation at a depth of 3,000 feet, the sealant is preventing formation water migration into the salt and pressure build-up on the concrete lining of both production and service shafts. The salt protection rings are not under the hydrostatic pressure of the formation water.The chemical sealant in use has the unique property of imbibing water and swelling. •Therefore, any water at• tempting to flow by the seal ring actually produces a tighter seal.The purpose of this paper is to discuss the sealant and its properties and uses. Installation of the material and its operation in two Canadian mine shafts is described."

Jan 1, 1971

By K. E. Haque

"This paper is a brief overview of the role of oxygen in cyanide leaching of gold feeds (e.g. ore, concentrate). As the majority of gold occurs in the elemental state (Au °), its oxidation is of vital importance for dissolution in the cyanide lixiviant. The cyanidetion at high pH is favourable for the oxidation of Au° with a mild oxidant such as air or oxygen. Beside oxidation of gold, deleterious effects of soluble sulphides, arsenates, antimonates on cyanidation of gold can be alleviated by preaerating the leach slurry with air or oxygen (i.e. preaeration process).If gold is refractory due to its occlusion in sulphides, silicates, tellurides, etc. then gold liberation is possible by roasting in the presence of oxygen or by leaching under oxygen pressure. The data in the recent literature indicate that reactive oxygen supplied by H202, Na202, Ca02 or 03 during cyanidation can accelerate considerably gold oxidation-cyanidation and yield high gold recovery in much shorter leach time. The information compiled in this review leads to the conclusion that oxygen plays a vital role in the dissolution of gold in cyanide lixiviant."

Jan 1, 1992

The Nak?azdli First Nation and the municipality of Fort St. James are located in the Stuart Lake/Nak?al Bun area and are not unfamiliar to mining. These northern British Columbian communities have been associated with the historic Pinchi Lake Mercury mine and today are closely linked with British Columbia?s newest mine, the Mt. Milligan mine. Prior to the construction of Mt. Milligan, community health and social service providers were concerned about potential impacts that would occur from new mineral development activities. This concern has led to a partnership between the above communities and researchers with expertise in the area of mining and health. This paper describes: the current mining and health environment with a focus on British Columbia; mining trends in the Stuart Lake/Nak?al Bun area; the current community-based health research project funded by the Vancouver Foundation and the Canadian Institutes of Health Research, and; a suite of community-based health recommendations to mining companies on key issues to consider when developing projects near municipalities and Aboriginal communities in Canada, based upon one of the newest mines under development in Canada.

Aug 1, 2013

By J. W. Senn

A magnesium alloy modeled after commercial alloy WE54 was thermomechanically processed and characterized to understand the mechanisms by which its texture can be randomized, as reported by Ball and Prangnell [1]. Samples were deformed in plane strain compression to prescribed strain levels at temperatures high enough to prevent cracking and then recrystallized. The deformation texture is very similar to that observed after plane strain compression (e.g., rolling) of other Mg alloys, such as common AZ31. However, the texture can radically evolve during recrystallization. Annealing above the precipitate solvus temperature results in a nearly random recrystallization texture where the initially strong basal texture is completely eliminated. Annealing below the solvus temperature produces a recrystallized texture similar to conventional Mg alloys, i.e., a weakened basal texture. If this same material is then annealed above the solvus to promote grain growth, a randomized texture evolves, which is similar that of samples simply recrystallized above the solvus. It is hypothesized that a sort of preferred growth mechanism, whereby grains with random orientation grow faster than those with the original basal texture, contributes significantly to the texture randomization observed in wrought magnesium alloys containing rare earth elements.

Jan 1, 2006

By L. Chunpongtong

The mining limit in oil sands is regulated by the ratio of total mining volume (ore, interburden, and overburden) one has to mine per volume of bitumen in place (TV/BIP). This paper presents a mathematical solution for creating the most economical pit outline where the TV/BIP ratio upper limit is 12, by combining mining economic theory and the Lerchs-Grossmann (LG) algorithm.

Jan 1, 2014

By Jianhong Xu, Hailong Hou, Yu Jing, Yundong Wang

Microcapsules containing extractants have been applied to the extraction of metal ions, organic acid, pesticide, and herbicide. The difficulties of conventional liquid-liquid extraction in phase mixing and phase separation (e.g. high energy consumption, emulsification phenomenon, and large equipment requiring housing) could be overcome in a liquid-solid system by using microcapsules. Even some extractants with high viscosity and poison can be encapsulated conveniently into microcapsules. In the work described in this paper, polysulfone microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507) were successfully prepared. Then, the extraction rate of lanthanum, samarium, and erbium in dilute solution into the microcapsules containing P507 was studied. An extraction kinetic model is proposed based on the interfacial reaction model accompanied by intraparticle diffusion expressed by Fick’s law. The extraction efficiency was obtained by using the kinetic model with the separately determined complex formation rate constant and the intraparticle diffusion coefficient. From the results, it was confirmed that the kinetic model could predict the experiment in a microcapsule system over a wide concentration range of lanthanide solution. In the future, the model could provide good guidance for the design and application in extraction of lanthanides.

Jan 1, 2014

By W. B. Burchall

Introduction In presenting this paper the author wishes to state that the opinions here given represent only his personal views. A general survey of the subject has been attempted, but such deductions as may have been drawn are not necessarily endorsed by the Company with which he is associated. The aeroplane as an instrument of transport is yet a novelty, for it is only twenty-five years since man first flew. This statement, by itself, may be very deceptive, for compared with the steam locomotive or even the auto-mobile, this infant in industry has made some remarkable showings. The 'actual performance' speed-curve of aircraft plotted over a ten-year period is rising faster than the 'expectancy' speed-curve of 1924 indicated, and it should be noted that, today, the possibilities of 600 miles per hour provoke less scepticism than did the prophecies of 400 miles per hour only a decade ago. Commencing with the remarkable achievement of raising one man into the air, aircraft with an all-up weight of 14 tons are now in daily use on the British airways, and recently a non-stop flight of 5,340 miles was accomplished in an aeroplane, without refuelling. More true than ever is the statement that the records of yesterday are commonplace tomorrow, for new ideas are today seized on and exploited to the utmost once the period of scepticism and doubt has been overcome. In fact, so many new ideas have been brought forward, during the past few years, and applied successfully in our economic life, that one may well ask if today we are not a little too impatient, too exacting in demands, forgetting that real worth-while progress -is attained by no short-cuts.

Jan 1, 1933

By W. D. Robbson

DR. G. W. RAMSEY (l): A study of our non-treatment silicosis autopsy material for the years 1940-43 inclusive, in addition to the common findings of fibrosis, nodules, and emphysema, shows marked thickening of the alveolar walls. This change is due to one or more of the following factors: congestion, edema, accumulation of both small and large monocuclear cells within the interstitial tissues and large monocuclear cells attached to the lining membrane of the alveolar sacs. This alteration in the alveolar walls, we believe, is one of the most important factors in producing impaired pulmonary function. Comparison of our first autopsy material of a case receiving twenty aluminium treatments beginning June, 1943, shows a striking change in the alveolar walls. In all areas free of silocotic nodules and fibrous tissue, the alveolar walls approach normal thickness and are free of cellular deposits. No change was noted in the old processes and none was expected. We believe that these changes in the alveolar walls were brought about by the aluminium therapy and that they constitute a major factor in the improved pulmonary ventilation noted in treatment cases.

Jan 1, 1945

By S. Minamiguchi

Grain refinement is effective to enhance strength and ductility of metallic materials. However this advantage has not been utilized fully for magnesium alloys in industry because microstructure control through thermomechanical treatment is difficult owing to their poor deformability. The authors proposed a high-speed heavy-reduction rolling for production of Mg alloy sheets. It was found that the deformability is significantly improved at high speed and that the thickness can be reduced 60% by one-pass operation even at room temperature without fracture at the rolling speed higher than 1000 m/min. In this study, commercial AZ31B sheets were rolled at 2000 m/min between room temperature and 350°C, and quenched immediately after the rolling. The sheets rolled at 200°C show the finest recrystallized microstructure with the mean grain size of 2.2 Rm. They show outstanding mechanical properties with the tensile strength of 293 MPa, and the elongation of 25%. It is concluded that high-speed rolling is very advantageous for grain refinement and improvement in mechanical properties as well as deformability and productivity.

Jan 1, 2006

By Afshin Sadri, Wai Lai Ying, Brycklin Wilson, Zoe Coull

"Although there have been great steps forward to integrate corrosion engineering into operations, there is still an underlying tendency for maintenance tasks to be performed in a reactive manner. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify leading indicators of failures. Prevention is generally less costly than repairs; moreover, when paired with appropriate monitoring techniques, intervention of corrosion protection can be more effectively timed and based on more accurate data. Hatch asset reliability studies show nearly 80% of defects are introduced through operations and maintenance. Therefore, proactive corrosion management can provide the necessary feedback to optimize operations and maintenance strategies preventing costly corrosion losses. Understanding corrosion risks gives a clear picture of the benefits of a proactive approach to asset performance. Monitoring techniques (Non-Destructive Testing, field testing, sampling, etc.) by nature are a more effective means of improving maintenance efforts and preventing corrosion losses than other methods (RCA, FMECA). This paper will outline the importance of proactive corrosion management and demonstrate its benefits through industry examples.INTRODUCTION Over the past few decades, with the growth of technology and awareness of sustainable development many studies have shown the benefits of a proactive approach to maintenance strategies. However, in practice there is still an underlying tendency for maintenance tasks to be performed in a “reactive manner”. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify defects and leading indicators to failures."

Jan 1, 2017

By M. C. Bluteau, G. P. Demopoulos

Arsenic reports in the effluents of many non-ferrous metallurgical operations. The production of scorodite, a crystalline ferric arsenate, is considered as an attractive option for the fixation of arsenic from aqueous effluents. However, scorodite solubility and long-term stability in the pH region of interest for tailings disposal have not been thoroughly investigated. In this study the long-term stability of scorodite in the pH 5 to 9 region and the mechanism of scorodite dissolution were studied. Construction of eh-pH diagrams indicated that scorodite stability is highly dependant on the nature (stability) of co-existing iron-hydroxide/oxyhydroxide. It was also found that when scorodite dissolves, a ferrihydrite phase having very small particles size (nano-scale) forms and that the growth and crystallization of this material are delayed by the presence of arsenate even under accelerated (75°C) ageing conditions. Around neutral pH and ambiant temperature (22°C) scorodite seems to reach an equilibrium with ferrihydrite after 48 weeks yielding soluble arsenic concentrations < 5 ppm.

Jan 1, 2004

By Serge Vézina

Environmental issues have evolved considerably over the last two decades. The main contributing factors, to name a few, have been the changing values of our modern societies, the globalization of trade and its linkage to environment, evolution and accessibility of information/communication technologies, better educated populations, climate change, long range transport of toxics and the increasing influence of NGOs and multistakeholders. As well, environmental management of mining operations had to be realigned in order to meet these new realities and to respond to more elaborated regulations oriented towards sustainability. Environmental Management Systems (EMSs) have emerged and have been introduced to meet not only the assurance of conformance to regulations but also to prevent pollution and to apply the continuous improvement of mining processes. EMS models have been developed and certification to international standards (e.g. ISO-14 001) is a common practice. Globalization has imposed challenges and additional requirements to environmental management. Developing a mine in emerging countries implies dealing with international agencies, local communities and a variety of government infrastructures to obtain a ?licence to operate?. This paper presents the structure of our EMS and how we have adapted its implementation to our operations in South America.

May 1, 2003

By Paul Johnston

or is it? Mining Automated Loader Technology Application ? Intelligent software mounted in hardware on a remotely controlled scoop. ? Led by INCO, Sudbury, with ? C-CORE, St. John?s ? Automated Mining Systems, Aurora ? Bell Canada, Sudbury ? Laurentian University, Sudbury ? University of Western Ontario, London Completed: March 2000

May 1, 2008

By Wei Huang, Anh V. Nguyen

"Potash flotation is an industrially proven success of flotation of soluble salts, but its collector adsorption mechanism remains elusive. In this paper, specific ion effects in NaCl-KCl flotation with carboxylate collectors were investigated. Flotation recovery and contact angle were determined as a function of brine composition of NaCl and KCl. The experimental results have shown that wettability of KCl and flotation of the soluble salts with laurate collectors were dependent on brine ion composition. Specifically, adding Na+ to brines decreased hydrophobicity of KCl crystals and their flotation recovery. Both KCl and NaCl could be floated with laurate collectors. However, flotation of NaCl was greatly enhanced by adding K+ to brine whereas flotation of KCl was significantly suppressed by the presence of Na ions. The decrease in KCl recovery upon adding Na+ is attributed to the counter-ion binding in the pulp. The flotation recovery enhancement of NaCl in the presence of K+ is explained by two effects: 1) increasing K+ concentration leads to a better dispersion of collector colloids in the pulp and 2) K+ enhances the collector adsorption at NaCl crystal surfaces. The water affinity matching rule can explain the specific ion binding behaviors and supported by the SFG spectroscopic results.INTRODUCTIONPotassium is an important fertilizer. Its primary source comes from potash ores, which are a mixture of sylvite (KCl), halite (NaCl) and many other complex double salts such as carnallite (KCl·MgCl·6H2O), alkali nitrates such as KNO3 and NaNO3, and sulfates-langbeinite (2MgSO4·K2SO4) with water-insoluble minerals such as clay and carbonate minerals. Previously, these salts were recovered with a lengthy hot leaching method, with further crystallization of potassium salts from saturated saline solutions. Selective flotation has been preferred since 1940s. Various collector adsorption mechanisms have been proposed soon after the industrial introduction of potash flotation. These include the formation of the insoluble compound model (Halbich, 1933; Singewald, 1961), an ion exchange model (Fuerstenau and Fuerstenau, 1956), a heat of solution model (Rogers, 1957), the surface hydration model (Schubert, 1988), the surface charge model (Roman, 1966; Miller et al., 1992), the interfacial water structure model (Hancer and Miller, 2000) and the colloid adsorption model (Leja, 1983; Burdukova and Laskowski, 2009). Most of the early exercises attempting to propose a unified rule on collector adsorption mechanisms can be seen as heroic endeavors due to the consideration of a vast number of salts in the pulp including alkali halides, nitrates, and sulfates, even the practically insoluble heavy earth metals. Additionally, several types of surfactants with different polarization features and alkyl chain length have been employed. As for the recent models, due probably to the preferential application of long chain amines as collectors in industrial potash flotation, most researchers are only devoted to collectors with low polarization features like amines and sulfonates (Hancer and Miller, 2000; Du et al., 2014). Collector adsorption mechanisms are therefore proposed based largely on a neglect of carboxylates as collectors. However, carboxylates remain an important collector type in soluble salt flotation systems where both salt minerals can be floated using anionic collectors and cationic collectors. Fatty acid type collectors are still one of the widely used collectors for soluble salt flotation and also one of the first to be applied on an industrial scale for the separation of potash ore (Hernáinz et al., 2003; Titkov, 2004). Here we examine some recent models that are relevant to our study to reveal a long neglected specific ion binding effects in potash flotation."

Jan 1, 2016

By Gordon MacVean

The object of this paper is to present for your consideration some of the present-day trends of safety practice in the coal mines in the United States and Canada. Coal mining at its best is a hazardous occupation. Men must be experienced miners in order to appreciate the existing hazards and must remain ever conscious of them if they are to work safely. The question is often asked whether our efforts for increased safety are showing results. So often it appears that strides are made for a period of a few years in the reduction of fatalities and lost-time accidents only to have all ground lost by an unfortunate year, after which progress is commenced again only to have a repetition of the same thing. Table No. 1 is an answer to this question. It shows the fatality rates over the last two decades in the coal mines of the United States and Canada. These are given in divisions of five years. The general trend is noticeably downward, exceptions being due to explosions or disasters which claimed an unusually heavy toll of life. These last are certainly not as common today as they have been in the past. It is only reasonable to suppose that this trend towards a lower fatality rate is the result of well directed safety effort. Reliable statistical organizations have offered figures to the effect that only 15 per cent of all accidents can be eliminated by the use of mechanical safeguards. The state of mind of the man involved, or his attitude towards safety, commonly called &apos;safety-consciousness,&apos; is the controlling factor in the prevention of 85 per cent of our accidents.

Jan 1, 1931

By M. Narita, S. Nakayama, M. Fujihara

Hibi Kyodo Smelting Co., Ltd. was founded in 1968 and celebrated its 50th anniversary in 2018. In 1972, we started producing copper cathode with a production capacity of 84 KTPY. Since the company founding, we have undertaken seven expansion projects, and our current copper-cathode production capacity is 290 KTPY. To increase our production efficiency, two tank houses were converted from Conventional process to ISA process in 2006 and 2014. In another investment, we equipped a continuous glue dosing system, which allowed for strict additive-concentration control, yielded quality improvements and reduced the power-consumption rate. Along with an increase in the production of copper cathode, the amount of impurities eluted from the anode increases. To solve this problem, the chelate-resin purification process that was introduced in 1983 was renovated, and impurities could be recovered more efficiently. In this paper, we report various improvements that have been implemented at the refinery since 2000. INTRODUCTION Tamano Smelter and Refinery of Hibi Kyodo Smelting Co., Ltd., founded in 1968, celebrated the 50th anniversary of its founding in 2018. The Tamano Smelter opened its No. 1 tankhouse in 1972, and began operating No. 2 tankhouse in 1984. Thereafter, with continuous production increases and technical improvements, electrolytic copper production was increased from 84 KTPY to 290 KTPY as shown in Figure 1. Table 1 shows the major operating facilities and operation data in 2017.In this paper, details of equipment introduced to continuously dissolve and add glue, various improvements made to the chelate resin process, enhancements made to the crude Ni sulfate process, and another vibrating screen introduced to the copper slime processing flow in accordance with the expansion of copper production capacity since 2000 are reported.

Jan 1, 2019