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By Elma van der Lingen

Gold is considered the most inert of all metallic elements, but the metal can show catalytic activity when prepared by specific techniques. Preparation techniques being used to prepare gold catalysts systems mainly involve precipitation methods incorporating gold compounds or complexes. This paper introduces a totally different method for the preparation of gold-based heterogeneous catalysts that can be used for oxidation and reduction reactions, as well as electrocatalysts. The method involves alloying of gold with a less noble metal, such as aluminium, to form a gold-containing intermetallic precursor. AuAl2 was produced by melting gold and aluminium together in a vacuum arc furnace under a protective atmosphere. The aluminium is then dissolved from the AuAl2 precursor by means of NaOH to produce a highly porous gold structure. The paper also reports on a method of incorporating transition metal oxide(s) with the porous gold to form an active heterogeneous catalyst. Promoter elements can also be melted with AuAl2 to improve catalytic activity. Alloying has the advantage that the promoter element can be in contact on atomic level with the gold. In-situ xray photoelectron spectroscopy (XPS) studies have also been done on the porous gold catalysts to further clarify the CO oxidation mechanism on gold-based catalysts.

Oct 1, 2003

By Y. M. Shneerson, I. V. Fomenko, M. A. Pleshkov, E. A. Ospanov, A. A. Shakhalov, S. S. Naboychenko

Low-grade copper concentrates (with copper content less than 20%) often contain impurities such as arsenic, zinc, lead, mercury, antimony and bismuth. The pyrometallurgical treatment of such concentrates is associated with several problems, which will ultimately affect the cost and the quality of copper cathodes as well as by-products. SRC Hydrometallurgy proposed a complex hydrometallurgical technology which allows the removal of impurities and the enrichment of low-grade copper concentrates to a quality which will be more suitable for pyrometallurgical processing. Laboratory batch tests and pilot plant results for the pressure leaching steps are shown in this paper. The key parameters of the leaching steps were determined and optimized. The quality of possible by-products were also determined. The developed flowsheet includes two pressure leaching steps: pressure oxidation (POX) and hydrothermal alteration (HTA). Both operations are carried out at 170°C with subsequent flotation of POX and HTA residues and recovery of copper, zinc and lead into separate concentrates for further processing. The development of the flowsheet was based on the Balkhash Zinc Plant (Balkhash, Kazakhstan), which had been non-operational since 2009. The developed flowsheet for processing of low-grade concentrates will utilize 80% of the existing equipment of the Balkhash Zinc Plant, thus leading to a significant reduction in required capital expenditure. INTRODUCTION As the age of copper mining operations advance, copper grades continue to diminish and impurity levels increase. Therefore, copper producers are forced to look for new innovative hydrometallurgical technologies which are able to handle low-grade raw materials and solve problems associated with impurities in an economically justifiable way. New technologies allow to extract valuable components selectively and to process low-grade concentrates which had previously been marked as non-technological and economically unviable. Hydrometallurgical technologies for processing of copper-containing materials can be divided into two main categories: chloride and sulfate (atmospheric, autoclave and bacterial) based technologies. Since the 1970s, many autoclave techniques for the processing of copper-containing materials have been developed and implemented (Naboichenko, 2002; Dreisinger, 2005; Habashi, 2009; Shneerson, 2011). The mineralogical composition of the ore (or concentrates), geographical location of the deposit, distance from industrial areas, availability of existing treatment facilities, availability of skilled labor, cost of electricity and cost of neutralization are some of the factors which are usually considered when the appropriate technology is selected (Halbe, 2002).

Jan 1, 2019

By J. A. H. Church

My paper entitled "Spontaneous Combustion of Coal in Mines;" read some time ago before this Branch, consisted chiefly of extracts from the British Blue Book dealing with the same subject. Fallowing my article, Mr. de Hart submitted a paper dealing with the application of existing methods of working in Alberta to the conditions obtaining in our bituminous mines. I must confess that the perusal of his paper did not enlighten me either as to what might be a method preferable to those in vogue or even to Mr. de Hart's ideas on the subject, nor did the ensuing discussion of Mr. de Hart's paper afford any great clarification of the problem. The outstanding idea, supplied by Mr. Dick, seemed to be that a retreating system could not be employed, as no operator would feel justified in risking the capital necessary to driving to the boundary when the whole might be jeopardized by a fire breaking out in the waste. That a fire would break out in the waste of any adit-level working seemed to be conceded by all, and with that I agree; that an ignited waste could not be safely sealed off by means of stoppings in a coal barrier-pillar appeared to be the contention of Mr. Dick, or perhaps he attributed this idea to the Mines Branch-anyhow, it seemed to loom over the discussion like a miasma. With this aspect I do not agree, as ? reliance is placed wholly on stoppings in the thick seams of South Staffordshire, even in fiery mines. In the thick coal at Exhall colliery, or elsewhere in Warwickshire (34 feet 4 inches) containing hard and soft coal in layers, a fire assuming serious proportions is sealed off. By the way, retreating long-wall methods are employed. In Fifeshire, sealing off fire in the Dysart mine has been accomplished successfully. The seam averages about 20 feet thick.

Jan 1, 1924

By Karina Forster

Rock mass characterisation is a critical component of effective stope design. Unexpected excessive stope dilution or uneconomic stope sizes can be the result of rock mass characterisation that is not representative of actual stope conditions. Comprehensive characterisation of the rock forming the stope hanging wall, back, ends and footwall is best done by a rock mechanics or ground control expert, however, this is time consuming and is often limited by available access. There are two general approaches for characterising a stope hanging wall for dilution estimating. Detailed classification and mapping data can be collected in local areas where good exposure is available. Personnel, exposure and time are usually not available to do a thorough analysis for all stopes. The stope hanging walls are then broken into lenses or domains and similar conditions are assumed for each area. The second approach consists of using readily available data such as RQD. Other rock mass properties which influence hanging wall behaviour are estimated based on back analysing a few case histories. Stope design is then based on the variability of the one parameter, such as RQD, that is consistently measured for the rock mass surrounding the ore body. This paper presents a third approach which looks, in depth, at the interpretation of geological core logging data for rock mass characterisation. Several rock mass properties that influence stope design, such as joint alteration, rock mass strength, joint spacing and orientations, have been linked to data collected by the mine geologists. This drill hole logging data was calibrated against underground mapping and used to back analyse the dilution prediction for mined-out stopes.

May 1, 2006

By Douglas A. Sloan

"Recently, a number of major mining companies seemed unable to find a president from within the industry, and were searching outside the industry. From this, one could conclude that managers within the industry are either not being prepared or are not preparing themselves for presidential responsibility. Opinions were sought from a number of senior executives, to attempt to define the skills a prospective president should acquire and what actions a company could take or that a prospective president could take to acquire these skills.This paper contains summaries of the opinions obtained, along with the author's comments. The paper also describes the actions some companies are taking and the actions that an aspiring president can take to prepare himself for corporate management.IntroductionA manager is promoted up the management ladder when the manager's superiors believe that he is capable of handling a more senior position. Normally, the manager acquires this credibility by outstanding performance in his current management post, whether it be in a junior management (supervisory) or in a vice-presidential capacity.In most instances, the skills required for promotion can be acquired in the current position or, at worst, the abilities exhibited in a candidate's current role will convince his superiors that the necessary expertise for the more senior position can be acquired on-the-job. This is particularly the case when the new skills are felt to be an extrapolation of the old skills.However, in the case of appointment to presidential rank, there appears to be a need for new expertise which often is not acquired in normal management progression or, at least, boards of directors of some mining companies seem to believe this to be the case. The objective of this paper is to attempt to define the new skills that should be acquired by a manager who aspires to be the president, and to describe what actions might be taken by him to acquire them."

Jan 1, 1982

By Jose R. Hernandez-Aguilar

"This paper revisits data from previous studies (Hernandez-Aguilar, 2010, 2011) to better understand the link between metallurgical performance and bubble size (Db) in the collection (pulp) zone of full-scale flotation systems. To obtain conclusive evidence exclusively related to the collection zone, the experiments were designed in those studies to control both the bubble generation method and the influence of the froth zone on the overall metallurgical performance in industrial and pilot-scale flotation columns. The results showed that generating small (1 mm) bubbles had a significantly higher beneficial effect on the recovery of coarse (> 75 µm) particles compared to the effect on fine (< 16 µm) particles. It was observed that, under certain practical conditions, the recovery of liberated coarse particles was close to zero, but could be recovered almost completely by reducing bubble size. The evidence revealed an apparent inconsistency of the so-called “k–PSb” model: at constant froth recovery, increasing Sb did not always result in higher recovery, as the model predicts. Overall, the evidence showed that it was not the Sb but the bubble size that proved to be a more reliable link to metallurgical performance. Only under highly suboptimal bubble size conditions (Db = 3 mm) did the froth zone seem to play a role, possibly reflecting an effect of pulp-zone bubble size on froth stability. However, for the most part, both the bubble generation method and the froth zone played inconsequential roles. An empirical model that better describes the kinetics of particle collection is proposed.INTRODUCTIONStudies showing the link between metallurgical performance and the interactions of bubbles and particles in the collection (pulp) zone of industrial flotation systems are scarce. A common belief among a number of mineral processing practitioners considers that “small” bubbles are favourable to recover “small” particles and that, conversely, “larger” bubbles are more efficient at floating “coarse” particles. However, perceptions like this are often substantiated by anecdotal evidence rather than by rigorous data analysis. What is the optimum bubble size for a particular case, how operating conditions can be adjusted to control a target bubble size, and whether the bubble size needs to be changed in the first place to optimize the operation of a flotation plant are questions that usually remain without solid answers.The studies reported by Hernandez-Aguilar (2010, 2011) were, in part, performed to test the effect of bubble size on flotation response and, thus, help address some of the above questions. The focus of the studies was to optimize the metallurgical grade-recovery performance of the Cu-Mo separation plant at Teck’s Highland Valley Copper mine (HVC). The outcome was compelling and significantly valuable: consolidated production data showed that in 2008 – the year when the recommendations from the studies started to be implemented – the Mo plant recovery was 89%, and gradually increased to 92% and 94% in 2009 and 2010, respectively, along with an increase in Mo concentrate grade. (Note: these production figures were not included in the publications quoted above; however, they were shown during an oral presentation at the 43rd Annual Meeting of the Canadian Mineral Processors in 2011.)"

Jan 1, 2016

Presentation Overview ?? Project Setting ? Project Context ? Challenges ?? Managing Commitments ?? Project Update ?? Maximizing Aboriginal Economic Participation in Resource Development PROJECT SETTING ?? Developed on the traditional lands of the Labrador Inuit, and the Labrador Innu ?? Courts have held that Aboriginal peoples in Canada possess special rights to traditional lands ?? Rights can include requiring resource developers to enter into Impacts and Benefits Agreements ?? Development agreement with Newfoundland and Labrador was required

May 1, 2004

Abstract-This paper discusses the fundamental question, "what is an adequate sample size?" in the light of recent developments regarding parameters of Gy’s well-known formula for predicting sampling variance. New understanding of the granulometric factor, g, and the liberation factor, l, had significant impact on the results of calculations involving Gy’s equation. For the granulometric factor, justifications are given as to why nominal comminution size should always be reported as P95 (i.e., the screen size rejecting 95% of the mass). A small but important change in the model to estimate the liberation factor makes the difference between a predictive formula that works or does not. Other parameters and considerations regarding their practical implementation are commented upon in light of the author’s experience.

Jan 1, 1998

By T. R. C. Aston, C. M. K. Yuen, J. L. Gilby

"The access tunnels for the Donkin-Morien Mine in Cape Breton, Nova Scotia, comprise two parallel tunnels driven through a sedimentary sequence of sandstone, siltstone and mudstone to intersect the Harbour Coal Seam under the Atlantic Ocean, approximately 3.5 km offshore (Fig. 1). The No. 2 tunnel was driven a total distance of 3579 m using a 7.6 m diameter Loyat full-face tunnel boring machine (TBM) and was supported by steel sets. The No. 3 tunnel was initially driven a distance of 1027 m using drill and blast methods (dimensions 7.6 m wide by 5.3 m high) supported by rock bolts and shotcrete. This tunnel was then completed (front March 1986 to February 1987) using the tunnel boring machine to a distance of 3573 m.During the period May 1983 to December 1984, a major geotechnical research program was undertaken in the Donkin-Morien tunnels by Golder Associates in conjunction w,ith CANMET and the Cape Breton Development Corporation (Yuen et al., 1985). The research program included the monitoring of the performance of the TBM and drill and blast drivages, and the study of the thrusting characteristics and rock-interaction of the TBM excavation. The main emphasis of the research program was on the collection of field data which was to be made available in the form of a comprehensive report for the future use of others who might wish to carry out a detailed interpretation and analysis. The information gained from the program was also used during the tunnel"

Jan 1, 1988

By Thomas S. Falk, Nils G. Lindberg

The first industrial COBO (Cold Bound) pelletizing plant began operation in May 1975 at Trollhiittan, Swede n. A technical description of the process, together with operational experience with the plant, forms the basis of this paper.

Jan 1, 1976

By Henri F. Letient

At the 25th Annual B.C. Mine Reclamation Symposium in September 2001, Huckleberry Mines Limited received the Jake MacDonald Reclamation Award for its exemplary mine waste management plan, conceived to prevent the onset of acid mine drainage and facilitate reclamation of the site. The mine is an excellent example of a total mine waste management plan, with all materials scheduled in detail for the life of the mine. The filling plan for the waste management facility takes into consideration the requirement for permanently flooding the potentially acid generating rock. From an acid generation point of view, the tailings fall in the zone of potentially acid generating material. To avoid long-term ARD concerns, it is planned to float pyrite out of the tailings towards the end of the mine life, thereby generating a non-acid generating tailings stream which will be used to cap the deposited mine waste. The pyrite-rich tailings will be discharged into the deeper portion of the impoundment. On closure, a permanent water cover will be maintained over the mine waste. Only beaches of non-acid generating tailings will remain exposed. Mining will be phased to also allow one of the pits to provide storage for potentially acid generating rock and to be flooded at the end of mine life.

May 1, 2002

By Chri Langille, Dougal McCreath, Samantha Espley

"In 1993, trials of two innovative applications of liner support involving the replacement of bolts in the ground support system were undertaken at Inco mines. The first trial involved an evaluation of the effect of dynamic loading on mesh-reinforced boltless shotcrete in a sub-level cave mining area on 2400 level at Stobie Mine. The second trial involved an evaluation of the MIROC Mineguard spray-on liner as a replacement for bolts and screen support, or as a replacement for screen support alone, in a topsoil heading of a bulk, VRM (vertical retreat mining) stope on 3240 level at Lower Coleman Mine.In the Stobie Mine trial, an uppers retreat heading was supported using a two-pass system. First, shotcrete was applied 2 inches thick, followed by pinning of mesh screen to the back and walls. A second pass of another 2 inches of shotcrete was then performed. For recovery of the ore zone, a vertical slot was created using a Borepak blind boring machine. The uppers rings were blasted, one or two rings at a time, starting at the slot and retreating out of the heading. During blasting of the production rings, blast monitoring was used to record the ppvs (peak particle velocities). For a series of 5-ring blasts, the maximum ppvs were measured to be 0.4 m/s (16 in./s) with a maximum charge weight per delay of357 kg (800 Ib). Six 5-point convergence measurement stations were set up and after each blast the total rockmass convergence was measured using a tape extensometer. Although a maximum displacement of 100 mm (4 in.) was measured, the shotcrete still managed to provide some support junction. A support damage assessment was also done to try and relate blast vibration to effectiveness of the mesh reinforced shotcrete liner. This trial demonstrated the effect that blasting has, on a support system, and it also demonstrated the necessity of having the mesh reinforcement properly placed within the shotcrete."

Jan 1, 1995

By Edgar A. Manker

"Today&apos;s market for columbium has only developed in the last two decades, and in this sense it is ""newer"" than molybdenum, vanadium and most other steel alloying elements. In this short period, it has assumed a very important role in steel alloying and in superalloys. From a few hundred thousand pounds of columbium in 1960, consumption has grown to nearly 30 million pounds per year, with a market value approaching two hundred million dollars.To assess the outlook for columbium, we will first consider the historical development of consumption and supply, particularly noting that all of today&apos;s major mines were developed during the last two decades. From current production, we will attempt to reasonably project the future. This future may well include new producers, particularly some producing columbium as a co-product with tantalum.The growth of current applications, and emerging new applications, will be considered with regard to future consumption and in relation to future trends in pricing.IntroductionThe nineteenth century was a busy time for the discovery and naming of new elements. Among those discovered were columbium in 1801 and niobium in 1844. Although it was later shown that columbium and niobium are the same element, the two names are still used today. Niobium has been pronounced the ""official"" name by the International Union of Pure and Applied Chemistry, but columbium is still widely used in commercial practice, and we have chosen to use columbium in this paper."

Jan 1, 1981

By G. Zeng

Although the solubility of oxygen in zinc electrolyte is less than 9 mg/L, the effect on deposit stability and zinc-dust consumption can be significant. Sodium sulfite is used to deoxygenate the electrolyte. The effect of the sodium-sulfite concentration on cobalt removal is investigated. The results show the reduction of sulfite to elemental sulfur that adhered to the zinc dust surface forming a passivating layer, and small amounts of sodium sulfite have no effect on cobalt removal. The optimum amount of sodium sulfite is 100 mg/L. It is an important consideration in purification circuits to use sodium sulfite as an additive to cobalt cementation.

Jan 1, 2005

By W. Roy Dunbar

"The Porcupine area is in northern Ontario at the intersection of N. Lat. 48° 30' and 81° W. Long. It is 125 miles due north of the Sudbury nickel range. Practically all the mineral production of this area has come from the townships of Tisdale, Deloro, Whitney, and Ogden, in order of importance. The accompanying map of the Porcupine area and its extensions to the east and west (Fig. 4) has been included to show what I consider to be an essential objective of this paper, a perspective for exploration.The discovery of gold ore in the Porcupine area at such an early date resulted from the extension of the Temiskaming and Northern Ontario railway and exploratory survey lines north into unexplored territory, for the early history of Porcupine is inextricably tied to the exploration along Niven's survey lines and the extension of the railway north from Cobalt to Nellie Lake. The following are the more significant events leading to the discovery of gold in Porcupine.1896-E. M. Burwash, employed by the Ontario Bureau of Mines, examined the country along Niven's base line and noted quartz veins that carried traces of gold. He was attached to Niven's survey party.1899-The late W. A. Parks reported on the geology of the portage route from Mattagami river to Night Hawk lake, for the Ontario Bureau of Mines. He noted the occurrence of gold in quartz veins and reported “I regard the region south of the trail to Porcupine lake as giving promise to the prospector"". He also was attached to Niven's survey party.1901-Charles Camsell, while prospecting for the Algoma Central railway, did some work on a vein occurrence carrying low gold on ground now known to be part of the Hollinger mine (3).1907- Extension of the Temiskaming and Northern Ontario railway to Nellie Lake.1909- Bannerman followed up Indian story about occurrence of coal, and found iron formation. He remained to prospect and found the gold-bearing vein of the Scottish Ontario property."

Jan 1, 1954

By H. C. Cooke

Those who have followed the geological developments in connection with the copper deposits of Quebec will recall that on many properties the sulphide bodies occur as replacements of fault breccias or tuff breccias, and exhibit a pronounced distaste for the more massive lavas. At the same time the rocks around the ore-bodies are profundly altered, first by addition of silica and sericite, later by conversion of these minerals into chlorite. It has been known for some years that at the Amulet and Waite-Ackerman Montgomery mines these conditions do not prevail. At both mines the ore-bodies are replacements of massive lavas, and at the Amulet they are associated with a very peculiar rock christened ?spotted dog&apos;, or &apos;dalmatianite&apos;. Accordingly, when in 1929 the writer had the opportunity to make a further examination of these properties, two problems presented themselves for solution. The first was to determine, if possible, the conditions under which massive lava, rather than breccia, is replaced by the sulphide masses; the second, to find out the exact nature of dalmatianite and its relations to the sulphide bodies. The first of these problems is believed to have been solved; the second has been found very complex, and will require further work before it is satisfactorily settled.

Jan 1, 1930

By CRO CRO

Elk Valley Coal?s Cheviot Project is located in the Alberta foothills south of the town of Hinton. The mine has been in operation now for the 3 years. The start up and subsequent operation of the Cheviot project has been directly influenced by the Cardinal River Mine. As the Cardinal River Mine was winding down due to reserve depletion in 2004, the price of seaborne traded metallurgical coal jumped to record levels and customers began aggressively seeking new sources of supply. Several months later, the owners of Elk Valley Coal decided to begin mining at the Cheviot mining area, extending the life of the area?s operations by over 25 years. The Cheviot Project had been delayed by low coal prices, ownership changes and a complicated and lengthy regulatory process fueled in large measure by stiff opposition from a number of major environmental organizations. Chief to the startup of the project was the construction of a 23-kilometer-long haul road that would connect the new coal measures to the existing Cardinal River processing and rail facilities. Construction of this road was completed with the first coal truck making its first trip in October 2004. This paper will look at some of original assumptions, the actual mining experiences and the lessons that were learned while moving from the drawing board to the current development as it exists today.

May 1, 2007

By M. Wu, G. Plascencia, A. E. M. Warner, A. Vahed, T. A. Utigard

Nickel oxide granules formed by pyrohydrolysis of a chloride solution, were reduced in hydrogen. Below 400 °C, an incubation period was observed, followed by very slow reduction. In the temperature range from 400 to 600 °C, the rate of reduction increased with increasing temperature and increasing hydrogen pressure. Microscopic analysis showed that in this temperature range the reaction followed the shrinking core model. Above 600 °C, the reduction rate decreased noticeably before suddenly becoming very fast at and above 950 °C. Microscopy showed inner bands of metallization inside the outer metallic rim, indicating partial blockage of the interface between the reacted and un-reacted NiO core. At these temperatures, particle agglomeration and sintering were also found to take place. Surface segregation of sulphur may account for the slow down in reduction rate above 600 °C. From an industrial point of view, reduction should be carried out from 550 to 600 °C with as high a concentration of hydrogen as possible. If sintering and agglomeration are not of any concerns, reduction can be carried extremely fast at about 1000 °C.

Jan 1, 2005

By A. J. Faulds, K. C. Westaway, Z. Waszczylo

"PAH compounds have been found in the exhaust from all types of engines burning hydrocarbon fuels . They have also been found in the air over cities and in water. The authors report on a study to assess the concentrations of twelve different PAH compounds in several different environments in dieselized underground mines. In addition, the differences in the PAH levels and distributions in different mines will be demonstrated. Finally, the influence of blasting and the type of diesel engine used as well as the effect of catalytic converters in the exhaust system on the PAH concentration in the mine will be discussed.IntroductionMining methods have been altered significantly in the last 25 years; i.e ., the tools and machinery used underground have changed from electrically operated trains and other equipment to diesel-powered equipment. This has been done for several reasons: 1) economics, 2) convenience and 3) safety. Today, most mines are heavily committed to using diesel equipment.Although the introduction of diesel equipment has revolutionized mining methods and has been a tremendous boon to the mining industry, it has also created new problems. These problems arise because the exhaust from diesel engines contains several pollutants which can be hazardous to the health of the miners. These pollutants are CO2, CO, NO., SO2, oxygenated hydrocarbons produced during the buring process and unburned hydrocarbons. There are two classes of hydrocarbons, of which polynuclear aromatic hydrocarbons (PAHs or PNAs) are a part."

Jan 1, 1981

By C Kumar

Scaffolds are temporary structures built to facilitate construction activities on site. A considerable amount of resources are allocated to scaffolding on industrial projects. Variability in geometrical features and space accessibility of structures on industrial projects, in addition to involvement of different trades that share the use of scaffolds, requires an extensive understanding of scaffolding requirements. Hence, it?s important to plan and estimate scaffolding man-hour requirements for the different construction areas on an industrial site. Contributing factors involved in such estimates include the list of trades that work in a construction area, trade working hours, volume of work, geometry of equipment erected, etc. A simulation template for predicting scaffold erection man-hour values for individual construction areas in an industrial project was developed in Simphony 4.0. The template is based on mapping the geometry of equipment and other factors to man-hours of scaffold work. The template facilitates the use of distributions as inputs and produces a range estimate of scaffold man-hours. The mapping is based on a linear regression model derived from existing project data from PCL Industrial Management Inc. The template is being further developed to incorporate the ability to predict scaffold erection schedule and material requirements based on construction work areas or equipment lists of an industrial construction project.

Aug 1, 2013