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By Louis R. Bernier

Since 1978, most systematic studies of AMD passive treatment with limestone drains (LD) have dealt with coal mines in the United States. The authors present in this paper the first results of a triennial study initiated in 1999 on the performance of LD installed at the Ni-Cu Lorraine old mine site in Temiscamingue during a remediation plan that involved the installation of a cover with capillary barrier effects (CCBE) over the reactive pyrrhotite-rich tailings. Typically, a LD is a trench enclosed by impervious materials filled with crushed limestone and may be oxic or anoxic. Four LD (one filled with marble and 3 with dolomite) were installed at the Lorraine site. The LD have been in operation since May 1999 and are performing differently. The most contaminated mine effluent flows south and is directed towards 3 LD filled with crushed dolomite, while a 4th LD was filled with crushed marble and installed west. The LD filled with marble has been generating maximum alkalinity since the beginning of the passive treatment. Two of the dolomite drains have been generating alkalinity since mid-summer 1999, but one is not, even if a substantial pH raise was observed. A pH above 5.5 is required usually for the dolomite drains to start generating alkalinity. The installation of LD at the Lorraine site contributes significantly to the reduction of metals and sulphates loading.

May 1, 2001

By Z. D. Hora

Limestone of economic interest is widespread in British Columbia. Triassic deposits on Texada Island are a convenient 1idewa1er source of li111es1one for cemen1 and lime for 1he Pacific orthwes1. Permian limes/one near Pavilion Lake is used for quicklime, and a deposit near Kam/oops is used for cement. Quarries at Dahl Lake and Pwrmigan Creek serve local pulp and paper needs.

Jan 1, 1984

By M. F. Goudge

This paper is intended to call attention to the manifold uses of limestone in industry; to indicate the types of limestone desired by some of the large consuming industries; and to give some information on the resources of limestone in Canada, so that an idea may be obtained of the present and future possibilities for limestone production. The word limestone is used in the usual broad sense to include both high-calcium limestone and the highly magnesian variety known as dolomite, as well as all intermediate types. Lime is simply calcined limestone, and in this general paper its uses have been included with those of raw limestone. It is of interest, in dealing with this subject, to glance back over the early history of the utilization of limestone, for by so doing we see that limestone has been of importance to mankind since the beginning of civilization and has contributed in no small measure to the development of a number of the arts and sciences. One of the first uses, if not the first use, of limestone was in connection with the making of lime for plastering purposes. This use antedates civilization. In the day of the ancient Greeks and Romans, the art of plastering had been brought to a state of perfection that is not nearly approached by the modern artisan.

Jan 1, 1930

By N. B. Clarke

LIMESTONE, as a name, covers a great variety of stone consisting of varying amounts of calcium carbonate, magnesium carbonate, and impurities such as silica, alumina, and sulphate of lime. In the iron and steel industry, limestone is roughly divided into two classes, namely Calcite, when the magnesium carbonate content is below 10 per cent, and Dolomite, when the magnesium carbonate is over 10 per cent. In practically all metallurgical melting, the quality of the finished product is related to the character of the slag, and limestone is used as a flux to achieve the proper analysis and consistency. The function of the slag is to absorb the undesired elements of the bath and also to act as a protective cover over the metal. The carbonates of calcium and magnesium are the effective agents in fluxing, and the silica, alumina, sulphur, and other foreign matter are objectionable impurities which should be as low as possible, totalling not over S per cent and preferably below 3 per cent, since all of these so-called impurities must be fluxed by the lime and magnesia of the stone. When the lime and magnesia of the stone have to be used to flux its own impurities, there is that much less of these two oxides left for fluxing the impurities from the balance of the charge, and, as a result, more lime-stone must be used than is desirable with good practice.

Jan 1, 1939

By H. J. Rowley

THERE are many varieties of limestone, but for the general purposes of the pulp and paper industry, two classifications are sufficient: (1) High-calcium stone, which should be quite free from impurities and contain not less then 90 per cent calcium carbonate. (2) High-magnesium stone, containing not less than 25 per cent of magnesium carbonate. Before proceeding with detail on the use of limestone and lime in the industry, a few words regarding the pulp products made in Canada are desirable. By far the largest tonnage is made by grinding spruce and balsam logs on rotating sandstones or on artificial abrasive stones of the Norton or Carborundum types. This mechanical or groundwood pulp finds its largest use in the production of newsprint paper, of which it comprises about 80 per cent of the total fibrous substance employed-the remaining 20 per cent being unbleached sulphite pulp. No limestone or lime is directly employed in making groundwood pulp, as contrasted with the chemically prepared pulps, all of which require one or the other form of the base for their processing. Sulphite pulps comprise the next largest tonnage group. They are produced by boiling, under pressure and at elevated temperatures, spruce and balsam wood in chip form in solutions of bisulphites and sulphurous acid. The usual bisulphites employed are those of calcium and magnesium. Sodium, potassium, and ammonium bisulphites give progressively better pulps, but to date, in the absence of efficient recovery methods, cost has precluded their use.

Jan 1, 1939

By M. E. Holter

"Limestone-bearing strata are exposed in seven areas of Alberta, each situated adjacent to rail and road facilities. Six of these centers are located along the eastern edge of the Foothills and Front Ranges of the Rocky Mountains in western Alberta. The other is in northeastern Alberta, along the eastern margin of the Alberta Basin. High-grade limestones are present in Middle Cambrian, Upper Devonian and Mississippian strata. Middle Cambrian (Eldon Formation) limestones have been exploited only in the Exshaw area west of Calgary, where they formerly were used for lime production. Limestone beds of the Upper Devonian Palliser Formation are exploited at Exshaw and at Cadomin in west-central Alberta for the manufacture of cement. Reserves of high-grade limestone also are available in the Palliser Formation near Crowsnest Lake in southwestern Alberta and near BrUle, west of Edmonton. Upper Devonian limestones of the Waterways Formation are widespread in the Fort McMurray area of northeastern Alberta, but available data indicate they are of inferior quality to the limestone deposits of the Rocky Mountains regions. The Mississippian Livingstone Formation contains large reserves of high-grade limestone at several localities in the Rocky Mountains and Foothills. Commercial development of the unit is now underway at Crowsnest Lake and at Exshaw for lime production, and future exploitation of these beds is feasible at Blairmore and Nordegg."

Jan 1, 1973

By O. D. Maurice

"This paper will essentially update the information that is already known and published on the limestones of the Province of Quebec. The excellent report by M. F. Goudge (1935)m is difficult to improve upon and the areas of limestone quarrying are generally the same as they were at the time of Goudge's report. Our knowledge of the limestones of Quebec has been improved considerably in recent years by the publications of T. H. Clark, 2 who, since 1938, has been mapping and reporting on these lime-stones and has discussed their stratigraphy, their structural features, their history and their economic value. One economic aspect is the presence of natural gas in these formations and the possible occurrence of oil. A total of 150 test holes had been drilled to a depth of more than 500 feet by the end of 1967 and, in addition, at least 256 more shallow holes had been put down in the St. Lawrence Lowlands. The information from these test holes has greatly improved our knowledge of the thickness and extent. of the various formations of Paleozoic limestone and shale in Quebec.This paper will then review briefly the limestone occurrences in Quebec, using the old as well as the more recent reports as principal references"

Jan 1, 1970

By Gorzalczynski. Stan

The recent trend in underground mine developments is ?big is better?. This is most certainly evident in the mine shaft and the conveyances that operate within its compartments. Today, there are several new installations requiring mine cages that can transport up to 170 passengers. The technology in mine hoisting is advancing to address a combination of higher capacity requirements, deeper hoisting depths and faster winding rates, however, some areas of the hoist plant have not changed for the past fifty years. The most notable of these areas is the shaft compartment guide string and the conveyance mounted safety arrest mechanism. The technology in use today for the protection of passengers in a shaft conveyance from a hoist rope severance incident, remains conceptually unchanged from Elisha Otis? design of 1850. The actual retardation components, the safety dogs, have taken on several forms since Elisha?s invention with the last major design change occurring in the late 1940?s. The arrest of a free falling shaft conveyance requires that the shaft guides withstand the energy imparted on them by the safety dogs. There are some very real limitations presented by the use of wood for this application. The new hoisting era will most certainly continue to demand larger capacity equipment but also, an increased awareness toward safety.

May 1, 2002

By S. Gorzalczynski

The recent trend in underground mine developments is “bigger is better.” This is most certainly evident in the mine shaft and conveyances that operate within its compartments. Today, there are several new installations requiring mine cages that can transport up to 170 passengers. The technology in mine hoisting is advancing to address a combination of higher capacity requirements, deeper hoisting depths and faster winding rates, however, some areas of the hoist plant have not changed in the past 50 years. The most notable of these areas is the shaft compartment guide string and the conveyance mounted safety arrest mechanism. The technology in use today for the protection of passengers in a shaft conveyance from a hoist rope severance incident remains conceptually unchanged from Elisha Otis’ design of 1850. The actual retardation components, the safety dogs, have taken on several forms since Elisha’s invention with the last major design change occurring in the late 1940s. The arrest of a free falling shaft conveyance requires that the shaft guides withstand the energy imparted on them by the safety dogs. There are some very real limitations presented by the use of wood for this application. The new hoisting era will most certainly continue to demand larger capacity equipment, but also an increased awareness toward safety

Jan 1, 2002

"Eastern Canadian thermal coal mined at Minto, New Brunswick, and in western Cape Breton at St. Rose, Inverness County, Nova Scotia, contains 6-8 per cent sulphur. Both coals are high volatile bituminous. types. The Minto coal averages 18 per cent ash, 7 per cent sulphur and has a Btu rating of 11,900 per lb. Pyritic sulphur accounts for 75 per cent of the total sulphur and the remainder is largely organic; the amount of sulphate sulphur is negligible. This means that in a 7 per cent sulphur coal, 2 per cent is organic and 5 per cent pyritic sulphur. Pit-head St. Rose coal contains approximately 10 per cent ash, 7 per cent sulphur and 11 ,800 Btu/lb. The distribution of sulphur is different to that of Minto coal because about 12 per cent sulphate sulphur is present. Thus, a 7 per cent sulphur coal would contain 4 per cent pyritic, 2 per cent organic and 1 per cent sulphate sulphur.The iron sulphides, pyrite and, to a lesser extent, marcassite occur over a wide size range from large sulphur balls to crack fillings, lenses, and individual crystals and framboids. Coarse-grained pyrite and sulphur balls are easily separated during washing. It is the fine grain sizes, intimately mixed with the coal constituents, that are difficult to separate. Quantimet analyses of the fine grains in coal from both localities showed that about 50 per cent were smaller than 30 micron(1).No efforts have been made to wash the Inverness coal of Nova Scotia and in 1980 washing ceased in New Brunswick. Previously, the Minto coal was processed in an antiquated jig circuit which reduced ash from the strip operation run-of-mine value of more than 20 per cent to less than 18. More effective removal of ash and sulphur could clearly be obtained. Laboratory tests on both Minto and St. Rose coal have shown that ash rejection rates of 40 to 50 per cent at yields of 70-80 per cent were possible(2), Little information on sulphur removal was available."

Jan 1, 1981

By J. Y. Kim, Kenneth Stowe, Stephen Chryssoulis

"A series of flotation tests was carried out on Brunswick Mining ore with various pH modifiers (soda ash, lime, KOH) and added ions (ferric, nitrate, sulphate) in the copper lead rougher circuit. The main objective was to identify downstream effects on sphalerite activation and subsequent zinc rougher flotation. Some significant differences in zinc flotation were obtained. Most notably, soda ash and nitrate ions had a positive impact and ferric ions a pronounced negative effect on selectivity.Selected products from the flotation tests were deslimed at 400 mesh, washed with methanol, air dried, placed in teflon vials purged with nitrogen and stored at -15 degrees C. Numerous liberated sphalerite and pyrite particles were selected under a stereoscope and placed in rows on indium foil. The surface compositions of the particles were analyzed with an innovative laser probe (LIMS). The very small analysis area of the LIMS enables the surfaces of individual grains to be characterized. In addition, the rapid analysis time allows a statistically significant number of grains to be analyzed quickly.Surface lead appears to play a major role in zinc activation/flotation. Possible mechanisms are proposed to explain the variations in metallurgical performance at the different test conditions.IntroductionAlthough the bulk composition of mineral grains is an important consideration for the mineral processor it is ultimately surface composition and topography (edges and dislocations preferred sites for reactions) that control reactivity in flotation and cyanidation (passivation, encapsulation and preg-robbing). Determination of the surface properties of particles from process streams poses a particular challenge for the surface chemist for a variety of reasons, including:"

Jan 1, 1994

By W. B. Agocs

"AbstractThe airborne magnetometer data of the Marmora iron ore deposit at Marmora, Ontario, have been used as an example to show the mapped results obtained by the use of line spacings of from 1 mile to 14 mile. The maps are illustrative of the results which could be obtained from such line spacings for any type of geophysical survey, and they show the probability of 'missing' a feature of economic value if the line spacing is too coarse.The probability equations are given for the crossing of randomly oriented features whose maximum dimension is less than the spacing of the control lines for circular, elongate, and rectangular outlines. The equations are P = D/S; P = 2L/S; P = 2(L+W)/,.S; P = A/,.S; P = (2L(S+T)-L2),.ST; and P (D(S+T-,.D)) ST, respectively; where P is the probability; D is the diameter; L is the length; W is the width; and S and T are line spacings.IntroductionTHE EFFECT of station spacing, and the effect of the distance between the plane of observation and the plane of the source of the potential field anomalies, have been studied by geophysicists in the past.The purpose of this paper, however, is to illustrate the effect of line spacing •on the resultant mapped magnetic anomaly for a known magnetite mass, and to present the elementary probability equations for determining the optimum control spacing for detecting a particular type of feature. The effect of line spacing which is illustrated by the magnetic maps presented herewith would be comparable to results which would be obtained by any geophysical survey, since the contours between lines are of necessity interpolated."

Jan 1, 1955

By X. Cao, J. J. Jonas, Wanjara. P., J. Gholipour, E. Dalgaard

The linear friction welding (LFW) behaviour of near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti- 5553) was investigated. Microhardness measurements were performed in order to evaluate the mechanical properties of the welded material. The linear friction welded (LFWed) Ti-5553 was examined with optical microscopy and scanning electron microscopy (SEM) to evaluate the microstructure’s response to the thermomechanical conditions. Characterization of the welds included analysis of the microstructural features of the weld region and thermomechanically affected zone (TMAZ) in relation to the parent material.

Jan 1, 2010

By James L. Parks, David M. Kjos

"Significant increases in mill liner life and plant availability can be achieved by following guidelines that have evolved from over twenty years of practical experience with autogenous grinding (A0) and semi-autogenous grinding (SA0) mills. A0 and SA0 mill liner functions, performance criteria, designs, wear-resistant materials and maintenance procedures are reviewed. Operating practices that can lead to accelerated wear and breakage are discussed.IntroductionEfforts to improve the performance of liners for autogenous grinding (AG) and semi-autogenous grinding (SAG) mills began as soon as the modern, large-diameter versions of these comminution machines were first intalled in commercial plants twenty years ago . While concentrators with conventional circuits were typically running at 95010 or better mill availability, many of the new autogenous and semi-autogenous circuits were struggling to achieve 80% availability. Liner maintenance, which involves not only material and labour costs but also loss of production, was quickly identified as one of the major reasons for downtime.Today, liner designs and materials have evolved to the point where virtually maintenance-free liner life of two to three years is possible in autogenous mills and one year in the more severe operating conditions encountered in semi-autogenous mills. Of concern, however, is that hard-won lessons from the past sometimes seem to be forgotten or ignored during the design of new mills and the operation of existing mills. As liner suppliers, we are often confronted with performance problems that could have been avoided by applying well-publicized guidelines for liner design and materials selection.This paper provides an overview of AG and SAG mill liner functions, criteria for evaluating performance, designs, wear-resistant materials and maintenance procedures. Also, operating conditions that can lead to accelerated wear and liner breakage are discussed in detail."

Jan 1, 1990

By Richard N. Zimmer

This paper discusses the installation of corrugated steel linings in bored raises at Inco's Thompson Mine. The procedure for the installation of these linings is outlined and the relative advantages are compared with conventional methods of ground support. Future trends in the use of corrugated steel products are then discussed.

Jan 1, 1978

By Doug Milne

Linking Classification Systems with each other Similar Parameters between systems Different Rock Mass Properties Rock Mass Classification parameters and geology Different sources of data Commonly Used Rock Mass Classification Systems Q? = Q with SRF = 1.0 RMR? = RMR with no joint orientation correction RMR76 = 9lnQ + 44 RMR?76 = 9lnQ? + 44 RMR76 = RMR89-5 RMR?76 = GSI = RMR89-5 MRMR = ??MRMR

May 1, 2013

By A. Sutherland Brown

"The ProblemMany science activities receive substantial funding from governments without much direct economic benefit accruing to state or individuals. In contrast, the search for knowledge has never been an acceptable so le justification of geoscience activity, perhaps because of its utility right from its inception. William Smith's geological activities were embraced because of their usefulness in building canals. Utility has been expected ever since.For decades it has been accepted at senior level s of government, without much understanding of the process, that geological surveys are necessary as a basis of resource evaluation and utilization. Recently, government treasury board s, staffed with economist s, have questioned these near axioms and in many cases the budget s of geological surveys have reflected their stone y-eyed appraisal s. Are government surveys necessary? Can their functions be reduced? Can some or all of their functions be privatized?Government geologists have been muted in trumpeting their successes outside their own ranks. Companies have been reluctant to give specific public feedback on the work of government surveys that have truly aided or guided them toward discovery. Lack of acknowledged linkages between survey work and discovery has dogged survey managers in budget reviews. Impoverished surveys cannot perform adequately so the circle is completed and the doubters' prophecy fulfilled. This is the genera l problem; British Columbia is the archetypical province."

Jan 1, 1986

By Malcolm Scoble

School Values ?? Each other; ?? Students, & helping them develop intellectually, personally & professionally; ?? Freedom to pursue educational & research opportunities; ?? Home-work-life balance; ?? The geographic-business community in which we operate ; ?? The pursuit of excellence; ?? Our contribution to society; ?? Creativity & innovation; ?? Teamwork & collaboration; ?? Career development, achievement & reward.

May 1, 2008

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 pulp-zone bubble size (Db) in full-scale flotation systems. To obtain conclusive evidence exclusively related to the pulp (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 Db had a significantly larger 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 coarse particles was close to zero, but dramatically increased by reducing Db. The evidence revealed an inconsistency of the so-called “k–PSb” model: at constant froth recovery, increasing Sb (i.e., the rate of production of bubble surface area) did not always result in higher recovery, as the model predicts. Furthermore, 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 in the presence of suboptimal-sized bubbles (Db > 2 mm) did the froth zone seem to play a role, possibly reflecting an effect of pulp-zone bubble size on froth stability. However, the role of the froth was negligible for Db < 1 mm.High-resolution mineralogical measurements performed on process samples revealed that, regardless of the degree of liberation, Db had a profound effect on the shape of the recovery-by-size curve, particularly the coarse particle size fraction. This observation is key as it implies that the loss in efficiency associated with floating the coarse particles was not the result of neither particle hydrophobicity nor particle detachment issues: even in the absence of mechanical agitation, liberated and highly hydrophobic coarse particles did not seem to attach to the bubbles in the first place, an inefficiency that was corrected by reducing bubble size. The data analysis suggests that poor attachment efficiency can practically affect both fine and coarse particles but via different mechanisms which are discussed here."

Jan 1, 2017

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