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By T. Möller

Grinding mills are the heart of the mineral processing plant, and are production-critical machines which are required to achieve high availability. Liner wear life and a liner design that promotes ease of installation are important variables to achieve a high level of mill availability. Increased mill size results in more mill internal surface to protect, and more liner components to install and remove. This drives designers toward an increase in liner size to minimize the number of components to be installed by the liner handler. The liner attachment method can also have a large impact on mill availability as well as safety during installation. This paper outlines the experience from the development, installation and follow-up of liners installed in two 38' x 45' AG Mills at Boliden Aitik in Sweden. A new Poly-Met shell liner concept has been developed to minimize the number of liner components. The new Poly-Met shell liner components are made much larger than conventional Poly-Met or steel liners. This reduces the number of components to be installed/removed by the liner handler and helps to minimize installation time and consequently down- time. A new attachment system has also been developed to eliminate the need for the installation crew to be in the ?drop-zone? of the shell liners while installing the liner bolts. One interesting aspect of this project was the requirement to predict liner life for these new large format AG mills. The existing 22' diameter mills at Aitik provided a base-line reference for this purpose, and DEM studies were used in the project development stage to predict the wear life of shell liners for the new 38' diameter AG mills. The results from this study are included.

Jan 1, 2012

A direct comparison has been undertaken between laboratory wind tunnel experimentation and computational fluid dynamics simulation of a 3D manufactured analogue for a body of fractured broken rock, created with CAD/CAM techniques. Detailed descriptions of the ?design? of the analogue (using a discrete element analysis multi-body simulator), its manufacture (using computer aided design and 3D printing technology) and the laboratory experimentation (inserting the physical analogue into a laboratory scale wind tunnel) are presented. The agreement of the results of direct experimental observations on the manufactured analogue with the values from CFD simulations of those experiments justifies the utilization of a CFD environment for the practical investigation of geometric factors controlling air flow and heat exchange in complex assemblages of broken rock blocks. The ultimate goal is described, that of developing functional relations between bulk properties of such assemblages (such as their porosity and bulk density) and the low-level geometric factors that dictate the air flow behaviour, such as the equivalent perimeter length of the cross-sectional area available for flow, or average flow path tortuosity. A practical application area of the work in the mining context is also described; equivalent continuum air flow and heat transfer constitutive models developed on the CFD tool from such functional relations are useful in characterization of seasonal heat storage in large scale bodies (approximately 1 km3) of broken rock.

Aug 1, 2013

By Seungyeol Lee

Currently, a new construction method using a robotic system is widely spreading in construction sites. This study is related to the design of glazing robot?s teach pendant which can improve convenience of handling and hence improve the productivity through the efficient interaction between an operator and a robot while doing glazing works, e.g., curtain wall installing. The suitability of selection and arrangement of control switches was assessed according to mechanical motions of a glazing robot, and design guidelines for improving convenience and productivity were drawn up through questionnaires carried out by site operators. To verify the proposed design guidelines, working time comparison of the proposed teach pendant and the existing teach pendant was executed.

Aug 1, 2013

By C. J. Brown

Regeneration of hydrochloric acid steel pickle liquors has traditionally been accomplished by pyrohydrolysis. However, a number of factors have recently conspired to reduce the attractiveness of this approach. Moreover, the process is not amenable to small-scale operations. On the other hand, the standard technique for regeneration of sulfuric acid pickle liquors, which is the low-temperature crystallization of ferrous sulfate is applicable to any size operation. A similar technique has recently been developed to regenerate hydrochloric acid. Sulfuric acid is added to the ferrous chloride-bearing spent HCl pickle liquor. The temperature is then reduced to below 0°C, resulting in the crystallization of ferrous sulfate heptahydrate and liberation of free hydrochloric acid. Depending upon the crystallization temperature, variable concentrations of sulfate are left in the regenerated acid. Although this residual sulfate has an impact on the pickling characteristics of the regenerated acid, tests have shown that by adjusting the conditions, pickling rates will be at least equal to those using pure HCI, and an acceptable surface finish will be produced.

Jan 1, 2006

By A. J. R. Smith

"CANADA'S ECONOMY TODAY is about two-fifths larger than it was six years ago, as measured by the total volume of production of goods and services. Such an achievement has been a rare phenomenon in Canada's first one hundred years. Excluding the forced-draft expansions which took place under war-time conditions, perhaps only the first decade of this century recorded a performance of greater dimensions, when, with massive immigration, the opening up of the West and a powerful array of well-de-signed development policies, the country was looking forward confidently to a great future of nation-building in the twentieth century.What makes Canada's over-all economic advance since 1961 all the more remarkable is that six years ago there was virtually no one in this country who anticipated an expansion of such dimensions. Back in the buoyant conditions of 1956-57, perhaps such an achievement would not have seemed beyond our grasp. After 1957, however, Canada stumbled through an extended period of slow economic growth, high unemployment and substantial and widespread under-utilization of its productive capacity. By the early 1960's, conditioned by the emergence of substantial, persistent and pervasive slack in the economy, t h e r e were few Canadians bold enough to anticipate that their economy was about to embark on a Great Expansion. However, this •is, in fact, what occurred. Beginning early in 1961, Canada moved forward into a sweeping advance which grew into the longest and largest peacetime business expansion in Canada's first century as a nation -a truly great expansion by any standard of measurement. This strong thrust has moved Canada into the front ranks of over-all economic expansion among the industrially advanced nations in the 1960's."

Jan 1, 1970

By R. L. Bruening, N. E. Izatt, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and demand for higher performance end products expands. The Molecular Recognition Technology (MRT) process uses highly selective SuperLig® resins to remove desired metals from a variety of solutions in the mining and metals processing and recovery industries. MRT separation processes efficiently produce high purity metal products. In this paper, applications of MRT to metal recovery at mg/L to multiple g/L concentration levels are presented and discussed. Specific examples in the precious metal, nickel, cobalt, zinc, copper, and rare earth industries are given.

Jan 1, 2014

By Mei-Yan Yang, Qiu-Ying Wang, Ltd. Yunnan Yuntong Zinc Co., Guo-Mu Chen, Meng-Yang Huang, Peng Zeng, Guo-Feng Li

"Historically, alot of jarosite was found in the leaching residue when leaching indium from secondary zinc oxide materials. The reasons for the formation of indium bearing jarosite were theoretically analyzed. The influence of controlling the acidity and the addition of reagents on the indium leaching yield during secondary zinc oxide processing was investigated. In order to increase the leaching yield of indium, a measure of controlling the creation and destruction of jarosite was proposed. The production data shows that the leaching yield of indium was increased from 60 to 96%, and the content of indium in leaching residue simultaneously decreased from 900g/t to 100–200g/t when implementing such controlling measures.INTRODUCTIONIndium does not occur as independent minerals in the earth’s crust and is mainly associated with complex sulphide minerals. Specifically some sphalerites can contain as much as 900g/t of indium. Most indium is recovered from by-products of copper, lead or zinc metallurgy. Therefore, the research on the recovery of by-products in non-ferrous metallurgy is important(Sinclair et al, 2006). The main technologies used for this objective in China include: •,pre-neutralization-reduction-precipitation indium process(Yu et al, 2008), •,countercurrent oxidizing acid leaching process and sulphation roasting-water leaching process(Cao, 2005), •,oxygen pressure acid leaching of zinc concentrate-P204 extraction process(Yang et al, 2006), •,doubleacid leaching-solvent extraction process on lead dross from a reverbatory furnace flue dust(Liu, 2003),•,an acid leaching-solvent extraction process on smelting ash(Zhouet al, 2005). Although high pressure and extreme conditions can be used to improve extraction from high iron bearing indium residues(autoclave processing), mild extraction with lower cost and lower environmental impact are preferred.This paper describes both how the indium extraction using mild conditions in a secondary zinc circuit was quite low and, how through XRD and chemical analysis jarosite formation was found as the main cause. The paper then proceeds to discuss a method for improving the leaching yield and the application of this method in industrial practice."

Jan 1, 2016

By C. S. Gibson

INTRODUCTION I WELCOME the opportunity to speak on Programmes in Safety. The invitation to do so shows that those guiding affairs of the Institute in this District realize the practical importance of this subject. My remarks are intended primarily for mines having 100 to 400 employees, approximately. With minor modifications, however, they apply also to larger or smaller operations. Others, I hope, will derive benefit from this paper, for they, too, have a part to play in accident prevention; for example, contractors such as shaft-sinkers; manufacturers of equipment; and consultants and designers of mining, milling, and metallurgical methods. These troubled times stress, as never before, the importance of efficient operations in mining. The days are gone when neglect can be afforded. Safe working conditions and satisfied employees are essential for efficient production at reasonable cost. The mining industry of Ontario long has been keenly aware of the human aspects of this subject, and as a whole it has done much to decrease the frequency and severity of disabling accidents. The number of fatalities per 1,000 employees has been reduced from a high of 5 some two decades ago to an all-time low of 0.89 in 1948; the incidence was slightly higher in 1949, being 1.17 per 1,000. The reduction in non-fatal compensable accidents also has been outstanding, frequency having ?been reduced from over 200 per 1,000 employees some two decades ago to 54 per 1,000 at the producing mines in 1949. These statistics demonstrate progress. Nevertheless, the general picture still leaves much to be desired when viewed from two other angles.

Jan 1, 1951

By Roberto Pena, Cristhian Morales, Darwin Morales, Veronica Cambiaso

"This article makes evident the shortcomings of the current operation of oxygen pipes as well as the damages they cause and why they cause them. When focusing on the causes and effects of these drawbacks, it was possible to develop a new family of thermal lances that could pierce a taphole with the precision of a drill but with the capacity to complete the whole operation. Although efforts have been made to replace oxygen pipes since they are annoying, dangerous and inefficient, nobody had worked to improve the way the traditional oxygen pipe taps/perforates the furnaces and reactors tapholes. In fact, developments made in drills and robotic arms, have failed to replace the oxygen pipe, which despite their negative side effects have been used for more than a century. Observation and theory were key to radically transform this humble tool into a dependable and efficient support in the operation. A good news that it is worthwhile to share for the benefit of all of us, passionate about the world of pyro metallurgy.INTRODUCTION Normally, reports and papers prepared for conventions, symposia or other technical events related to metallurgy aim to relevant topics in the operational field, probably because in them lay the scale economies every company pursues. We intend to give relevance to a matter normally disregarded in operations, but that unmistakably vital: if the furnace or reactor cannot be bled, the pyrometallurgical process will not be completed. Besides, if the tapping task is difficult or is long delayed, the availability of the furnace will be reduced. Consequently, there will be a waste of energy and workers will be exposed to dangerous levels of radiation as well as to work overload and physical injuries Apart from these basic effects, in tapping operations where oxygen pipes are used, we can see serious damages in the smelting furnace, especially in the taphole components such as refractory bricks, taphole jackets and water cooled plates. This paper intends to show that taking care of the tapping task can significantly upgrade not only to the tapping operation itself, but also the whole plant productivity."

Jan 1, 2017

By Harry Jomini

Introduction The Wakefield plant of the Aluminum Company of Canada, Limited - a member of the Aluminum, Limited, group of companies - produces magnesia, magnesia fertilizer ingredient, and hydrated lime, from brucitic limestone. Wakefield is on the Gatineau river in Wakefield township, Quebec, some 22 miles north of Ottawa. The plant is near the western bank of the river adjacent to the Ottawa-Maniwaki highway and branch line of the Canadian Pacific railway. The plant is unique in the sense that it is the only place in Canada where brucite is processed. It is also distinguished for its outstanding safety record, as not a single lost-time accident occurred during either 1948 or 1949. The plant is amply provided with safety and comfort provisions in keeping with the standard practice in all of the twelve plants operated in Canada by Alcan and its associated companies. History Following the identification of brucite in the Rutherglen and Bryson districts in Ontario, occurrences of the mineral were discovered in the Wakefield area, Quebec, in 1939. After exploratory work on these deposits and investigation by the Bureau of Mines, Ottawa, on a method of extracting the brucite from the ore, a plant for treating the ore from the Maxwell property was built in 1941 by the Aluminum Company of Canada and commenced operations in early 1942. The process used is more or less in accordance with the method worked out by Mr. M. F. Goudge of the Bureau of Mines.

Jan 1, 1950

By R. M. Beauchamp

Base metal processing operations often treat process tailings and acid mine drainage using a high density sludge (HDS) water treatment process. Lime is used in this process, which reacts with existing sulfates to form gypsum. When a recycle stream is incorporated in the process, gypsum levels in recirculating water may build up and cause high levels of gypsum supersaturation. Precipitation of gypsum from the supersaturated process water causes many problems. It is speculated that gypsum may precipitate on sulfide minerals and silica gangues in the flotation circuit, resulting in decreased selectivity and recovery. An understanding of the determinants and nature of precipitation may provide solutions to mitigate the formation of precipitates and improve flotation performance. This study showed that both sphalerite and silica exhibited gypsum- or calcium carbonate-like behavior in the respective supersaturated solutions, indicative of a coating of calcium species on the mineral particle surfaces. The addition of copper sulfate and/or potassium xanthate had little effect on the precipitation of gypsum or calcium carbonate on the mineral particles. Sodium carbonate is encouraging as a method to minimize calcium species interactions on sphalerite/silica surfaces.

Jan 1, 2006

By C. Fortin

The subject of gold flotation has been reviewed extensively in a number of publications. The focus in most of these reviews has been on the theories of gold flotation as well as the physical and chemical effects that may impact the efficacy of the gold flotation process. It is evident that the current status of gold flotation chemistry as it is being applied in industry has not been addressed widely. It is the intent of this paper to review current gold flotation practice and how these applications tie in with the current understanding of the chemistry of gold flotation.

Jan 1, 2011

By M. G. Lipsett

One challenge in applying information technologies in Mining is building a business case. In Mine Maintenance, there is a complex flow of information that contributes to making informed business decisions. By understanding those information relationships and the cost of wrong decisions, analysts can estimate the value of information flow. Developers can then ensure that systems deliver key information in an accurate and timely way. In this paper, general maintenance decision-making is discussed, with examples of how model-based analysis can improve the information delivered to decision makers.

May 1, 2001

By A. Djebara

Today, indoor air quality, especially in manufacturing industries, is of great interest due to the use of new processes and advanced materials such as those containing nanoparticles. Manufacturing processes generate aerosols (dry or wet) which can be detrimental to occupational health and safety and to the environment. Controlling metallic particle emissions during machining processes should limit their formation at the source, and thus minimize the risk of exposure; this at-source reduction requires the characterization of the particle emitted (size, nature, concentration, etc). The metrics normally used in characterizing fine and ultrafine particles include the mass concentration, the specific surface and the number concentration. Most of these metrics are affected by the size, the geometry and the density of the measured particles. Information about the form and the real size of the particles is thus very important. A procedure for collecting and characterizing fine and ultrafine metallic particles was developed and applied to the study of particles emission during the machining of aluminum alloys. It was found that metallic particles emitted during the machining of aluminum alloys are of various shapes and sizes, and this information must be taken into account when characterizing these particles.

Jan 1, 2011

By M. Sukhram, S. A. Argyropoulos

"In the aluminum and steel processing industries there is a need for velocity sensors to measure the flow characteristics of liquid metal. This paper will present a sensor and an inverse heat transfer technique to determine the direction of velocity in flowing liquid aluminum. Experimental research work with the sensor involving liquid aluminum was conducted, using the Revolving Liquid Metal Tank at the University of Toronto, which rotates 50 kg of liquid aluminum with velocities up to 0.35 m/s. Experimental data for various magnitude of velocity demonstrate that the sensor records different thermal profiles under different fluid flow conditions. Using the transient temperature information and the inverse technique, the direction of velocity of the molten aluminum flow field can be inferred. INTRODUCTIONOur research at the University of Toronto has focused on developing invasive sensors to determine the velocity of high temperature liquid metals. High temperature in this setting is defined at VALUES (in excess of 660 °C. The discussion which will persist in this manuscript involves detecting the direction of flow in liquid aluminum using an inverse heat transfer technique. We first reported on the sensor which is used in this article in the following two publications (Sukhram and Argyropoulos, 2011a; Sukhram and Argyropoulos, 2011b). The motivation to perform this research is due to the lack of sensors available to characterize the conditions within a high temperature liquid metal reactor/vessel. A report conducted by The Minerals Metals and Materials Society (TMS Energy 2011) has suggested that the introduction of sensors into molten metal processing environments has the potential to increase process efficiency up to 15%. Such sensors will aid in the understanding of high temperature liquid metal processing operations with the goal to implement more efficient process design and practice."

Jan 1, 2012

By Michael S. Moats, Alex Luyima, Tomas Oliveira

Some commercial copper electrowinning facilities use Cyquest N-900 (a polyacrylamide) or HydroStar (a modified polysaccharide) to improve the density and smoothness of copper electrodeposits. However, the effects of these additives have not been studied extensively in the open literature. Thus, the electrodeposition of copper at 40 oC from a non-stirred synthetic electrowinning electrolyte (40 g/L Cu2+, 160 g/L H2SO4, and 20 mg/L Cl-) in the presence of various concentrations of either additive was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV results show that neither additive has much effect on the nucleation overpotential of copper electrodeposition on stainless steel. However, Cyquest N-900 polarized the copper deposition reaction upon the return sweep. The EIS data indicates that Cyquest N-900 increases the reaction’s charge transfer resistance and creates a second low frequency loop. HydroStar had minimal effect on the electrochemical data generated by CV or EIS. Thus, the mechanism by which HydroStar affects the copper deposition reaction still needs to be determined.

Jan 1, 2014

By Claude Bourgoin

"The Copra massive sulphide deposit occurs as a continuous slab of ore dipping at approximately 40 degrees within a sericite schist formation. The orebody has been delineated over a distance of more than 5,000 feet down dip. This paper is mainly concerned with the mining procedure, and particular reference will be made to the use of steel mill holes and hydraulic roof supports. The gravel backfill line, which is operated both by gravity and hydraulically, is described. The paper mentions some of the operational problems, discusses the feasibility of longwall mining and presents the information obtained from stope testing."

Jan 1, 1966

By Denilson Coutinho, Euler Soares, Paulo de Tarso, Jordana Ferreira, John R. Goode, Andreas Sprecher, Alexandre Rocha

The Serra Verde Project is located in the northern part of Goiás state, Brazil, and comprises 49 mineral claims covering an area of 69,814 ha. The Serra Verde deposit is a rare earth element (REE) enriched weathered granite comparable to the weathered granite, or ionic-clay, deposits found in southeastern China. The Mineral Reserves of the Serra Verde Project total 388 Mt (Measured and Indicated) at an average grade of 1,484 ppm of REE oxide (REO). Several hundred agitated leach and column leach tests have confirmed recovery of about 40 to 55% of the REE, except for Ce, using simple desorption techniques. Present plans call for a heap leach operation followed by precipitation of impurities and precipitation of a pure REE carbonate suitable for refining and separation. The project plan includes initial production of 5,000 t/a of REO, with a high content of heavy and critical REO, rising to 10,000 t/a of REO. This production rate will be obtained by mining of the Mineral Reserves over a 22-year mine life at an initial rate of 6 Mt/a for the first four years with the mining rate thereafter increasing as required by grade and production targets.

Jan 1, 2014

By Binbin Luo, Northeastern University, Chuanyao Sun, Jie Liu, Yimin Zhu, Yanjun Li

"A series of new type collectors a-bromo-saturated fatty acids, CH3(CH2)5CHBrCOOH (a-BHA), CH3(CH2)7CHBrCOOH (a-BDA), CH3(CH2)9CHBrCOOH (a-BLA), CH3(CH2)11CHBrCOOH (a-BMA) were synthesized from saturated fatty acids and bromine by solvent-free method (Hell-Volhard-Zelinski reaction) in laboratory. The micro-flotation tests of quartz mineral were conducted at a relatively low temperature of 15 °C. The adsorption mechanism of such collectors on quartz mineral surface were established by zeta potential measurements, in conjunction with the results of quartz micro-flotation tests. The flotation results showed that the collecting ability is in the order of a-BMA > a-BLA > a-BDA > a-BHA for the flotation of quartz mineral, which also demonstrating that the a-bromo-saturated fatty acids (a-BFAs) are new selective collectors for reverse flotation to remove quartz mineral from iron ores at a relatively low temperature.INTRODUCTIONThe requirement of higher pulp temperature to maintain the activity of fatty acid anionic collectors which have been widely applied in technological process of iron ores reverse flotation lead to a great deal of energy consumption.The purpose of this paper is to synthesize a new modified collector with carbon chains from eight to fourteen atoms, with strong electronegativity bromine atom introduced into a-carbon position to improve the activity and solubility of the reagent so that it can be adopted at a comparatively low pulp temperature. The collecting performances of these new collectors on quartz surface were studied, and the structure - properties were discussed in light of zeta potential measurements and quantum chemistry calculations."

Jan 1, 2016

By J. T. Liu, G. H. Han, W. C. Chai, Y. F. Huang

"In beneficiation process, metal ions could adsorb onto clay mineral surfaces or interact with flotation chemicals, and then result in the flotation behavior changing of desired minerals. Al(III) is the dominating ion existing in the bauxite flotation system. In this research, the adsorption behaviors of Al(III) on two silicate clay minerals (including bentonite and kaolin) were investigated by means of UV-Vis spectra, zeta potential testing and scanning electron micrograph analysis. The adsorption experiment results show that the adsorption capacity of clays for Al(III) ions increases with the initial Al(III) concentration, contact time and solution pH. There are some different adsorption behaviours for two clays. Increasing the clay concentration decreases the adsorption capacity of bentonite, while increases first then decreases for kaolin. Higher temperature favours the adsorption of Al(III) on bentonite but goes against for kaolin. The adsorption capacities of bentonite and kaolin for Al(III) respectively reach 12.48 and 0.875 mg/g at initial solution pH 5. Zeta potential results show that the adsorption of Al(III) on two clays is characterized by electrostatic attraction mechanism.INTRODUCTIONIn beneficiation process, there is inevitably a wide variety of metal ions generated from mineral crushing, mineral dissolution and water chemistry conditions. Metal ions adsorb on the mineral surfaces or interact with the beneficiation agents, affecting the flotation efficiency of desired minerals (DiFeo et al., 2001; Parolis et al., 2008; Shackleton et al., 2012; Shengo et al., 2014). Therefore, it is necessary to have a detailed investigation on the adsorption behaviour of metal ions on clay minerals.Having good ion exchange capacity and negative surface charge, the clay minerals could take up various metal ions from the mineral-water system. Bentonite and kaolin are very common aluminosilicate clays in the mineral processing system. These two clays both hold a permanent negative charge, =X- on the basal surfaces, and a smaller variable charge, =SiOH on the mineral edges (Gu & Evans, 2008; (Gu et al., 2010). Adsorption experiments are usually used to study the adsorption affinity of metal ions for clay minerals (Sen & Bhattacharyya, 2012). The adsorption of Zn(II), Cu(II) and Pb(II) onto natural bentonite showed that the adsorption amounts of metal ions increase with contact time, solution pH and metal ion concentration, but decreases with adsorbent concentration and system temperature (Sen & Gomez, 2011; Melichova & Hromada, 2013). Cr(III) adsorption on bentonite was significantly pH dependent. The adsorption process followed pseudo-second-order model and the equilibrium adsorption was consistent with Freundlich isotherm (Lollino et al., 2015). The adsorption behaviours of Pb(II), Cd(II), Ni(II) and Cu(II) onto kaolin indicated that increasing pH favoured the adsorption of metal ions (Jiang et al., 2010). The adsorption of Cd(II), Cu(II), Pb(II) and Zn(II) onto kaolin showed that an ion-exchange reaction occurred at pH<7.0 and inner-sphere surface complexes were prone to form at higher pH (Srivastava et al., 2005)."

Jan 1, 2016