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By H. Scott Swinden

"ForewordA symposium on base metal deposits was held in Bathurst, New Brunswick, from June 10-13, 1990, sponsored jointly by the Geological Surveys Branch of the New Brunswick Department of Natural Resources and Energy, the New Brunswick Prospectors and Developers Association, and the Geology Division of the Canadian Institute of Mining, Metallurgy and Petroleum . Papers prepared for the symposuim are being published as a series of articles in the CIM Bulletin. This second paper (the first was by Fyffe, et al., in Vol. 83, No. 938) in the series presents an overview of the paleotectonic settings of massive sulphide deposits in the Dunnage Zone of Newfoundland with emphasis on volcanic geochemistry.ABSTRACTCambrian and Ordovician volcanic sequences of central Newfoundland, which record the history of the Iapetus Ocean, are prolific hosts to volcanogenic massive sulphide (VMS) deposits. Geochemical, isotopic and geochronological studies show that the vestiges of Iapetus in Newfoundland probably record a complex series of island arcs and back-arc basins that were marginal to, rather than part of, the main ocean basin of Iapetus. The geochemical and isotopic data provide a means of characterizing the tectonic environment of individual volcanic sequences, and allow us to identify a number of distinct tectonic environments in which VMS depositiontook place.Four tectonic environments have been identified as being associated with VMS deposition: (I) back-arc environments hosting VMS deposits include both N-MORB-type ophiolites (e.g. Skidder?) and volcanic sequences with oceanic island (or within plate) tholeiite characteristics (e.g. Great Burnt Lake); (2) primitive arc environments include both supra-subduction zone (SSZ) ophiolites (e.g. Betts Cove, Rambler) and volcanic/epiclastic sequences (e.g. Point Leamington, Duck Pond) and are characterized by abundant arc tholeiites, with lesser refractory lavas and rhyolites; (3) mature arc environments comprise dominantly thick felsic and mafic volcanic piles in the Buchans - Robert's Arm Belt (including the Buchans camp) and are characterized by dominantly calc alkalic basalt and andesite; and (4) continental rift environments occur in the Hermitage Flexure area (e.g. Strickland deposit) and are characterized by dominantly felsic volcanic sequences.Island arc environments are by far the most prolific hosts to VMS deposits. Patterns of VMS distribution in central Newfoundland show that similar tectonic settings may be recorded by very different stratigraphic sequences (e.g. both ophiolites and thick volcanic/ epiclastic sequences may record primitive arc rifting) and emphasize the importance of the rifting in VMS generation, irrespective of the details of the tectonic or stratigraphic setting. The ability to judge the prospectiveness of a volcanic sequence by using whole rock geochemistry to evaluate its tectonic environment may prove useful in area selection at the grassroots exploration level."

Jan 1, 1991

By W. P. Campbell

In the course of the development of the Red Coulee field, northwest of Coutts, Alberta, a considerable amount of information has been gathered by the Department of the Interior regarding the chemical character of waters encountered in the drilling of wells in this area. The writer, in this paper, has undertaken to assemble the available material with the idea of deducing what relations, if any, may exist between the different waters from the same well, and also how these compare with waters encountered in similar horizons in other wells. From no other district, with which the Department of the Interior has had to do, have there been received so many samples of water, and yet not all the waters logged in the drilling reports were sent in for analysis. The information, therefore, herein contained is not as complete as the writer would have desired, but sufficient evidence has been accumulated to indicate some very definite tendencies in the chemical nature of the waters of this field. The drilling of Red Coulee wells has been carried out exclusively by percussive tools. These permit 'dry' drilling, and, consequently, water-sands are recognized when encountered. Had rotary tools been used, information regarding water-sands would have been very meagre, if not entirely lacking, since, in the mudding-off process, water-sands would have been overlooked, with the result that, should water break through into a completed well, its source would not be known and remedial efforts would be greatly handicapped, if not entirely defeated.

Jan 1, 1931

By Mehmet Guney

This article is based on a detailed heat investigation conducted at the Rokana Division of Nchanga Consolidated Copper Mines Limited while both authors were employed in Zambia. Mindola Mine is one of the three underground mines comprising the Rokana Division on the Copperbelt of Zambia, producing about 270,000 tons of ore per month at 1.9% Cu and 0.14% Co. The total volume of air being circulated by means of five primary fan installations slightly exceeds 1,000 m3/sec at standard density. Sectional bulk cooling is practised where air cooling coils are installed at primary splits some considerable distance from the stoping operations. Total capacity of the refrigeration complex is 10,500 kw (3,500 R. tons), of which about 7,000 kw is available as effective cooling power after losses, but the heat removed from the coifs is about 3,500 kw with 61% over-all plant performance. An extension program is planned for a further five production levels with the re-deepening of a sub-vertical shaft. Thermal heat will become a major problem at increased depth associated with higher rock temperature, higher thermal conductivity of the rock groups encountered and fissure water flowing into working areas through the strata with increased rock temperature. This paper describes the ventilation and refrigeration practices in Mindola Mine, with special reference to future thermal heat problems. These are discussed with a view to mining at depth.

Jan 1, 1979

By R. A. Price

The base of the biozone of Olenellus is accepted as the most universally applicable criterion for defining the base of the Cambrian System. The use of this definitive criterion is restricted by important practical considerations. In the southeastern Canadian Cordillera this zone appears to truncate the basal ortho-quartzite of a west to east marine -transgression. This transgression began in Interior British Columbia in the Late Proterozoic and terminated in the region of the present Rockies in the Late Waucobian. Most of the material deposited by the transgressing sea originated in the eastern positive element 'Laurentia' and was transported over the intervening low Proterozoic-Windermere erosion surface. The configuration of the advancing shoreline and the distribution of the sediments were controlled by the tectonic activity of positive elements in northwestern Montana (Montania) and in the Fairmont Hot Springs-Radium area of British Columbia.

Jan 1, 1956

By L. M. Guayacán-Carrillo, G. Armand, A. Noiret, D. Seyedi, S. Ghabezloo, J. Sulem

"The main purpose of this paper is to analyze the convergence measurements in a drift excavated in the Callovo-Oxfordian claystone. The drift axis is in the direction of the major principal horizontal stress whereas the stress state is quasi-isotropic in the drift’s section. The initial geometry of the drift being circular, the anisotropic character of the deformation is taken into account by assuming that the drift shape evolves in an elliptical shape. The convergence measurement data on six different points around the drift are analyzed to identify the main axes of the deformation ellipse, following the methodology proposed by Vu et al. (2013, Rock Mech Rock Eng, 46, 231-246). Then, using the semi-empirical law proposed by Sulem et al. (1987, Int J Rock Mech Min Sci, 24, 145–154), the convergence evolution is fitted independently for each axis of the ellipse. This method permits to distinguish two effects: the face advance effect and the time-dependent behavior of the ground. The results for the two directions of the ellipse axes show very close values for the parameters describing the time-dependent properties of the ground, the distance of influence of the face, and the extension of the decompressed zone around the gallery. Such model can provide valuable insights for predictions of the convergence evolution in the long-term. INTRODUCTIONDeep disposal of radioactive waste has been studied in France for more than two decades. The French National Radioactive Waste Management Agency (Andra) began in 2000 the construction of an Underground Research Laboratory (URL) with the main goal of demonstrating the feasibility of a geological repository in Callovo-Oxfordian claystone. Several research programs have taken place to improve the knowledge of the rock properties and its response to the excavation progress. The optimization of supports design for long-term behavior is an important point to develop. A network of experimental drifts has been constructed with variations on: excavation method, structure geometry, supports system and orientations with respect to in-situ principal stresses’ directions. In each drift different sections have been instrumented to monitor the convergence evolution and the rock deformation. Continuous monitoring of the excavated zone around the drifts revealed the development of a fractured zone (extensional and shear fractures) induced by the excavation. The extent of this fractured zone depends on both the drift orientation and the in-situ stress field (Armand et al., 2014). Indeed, the fractures distribution has an important influence on the convergence of the drifts."

Jan 1, 2015

By Kazuhide Nakaniwa

In this research, we devised a measurement method using total stations (TSs) which have ?the Baum? which is a concentric circle reticle, as substitute for crosshairs. The Baum owes its name to the similarity between the concentric circles and trees (Baum in German). By setting one circle on both of edges of cylinders, operators can set their sights on points on the center line of the cylinders, and also can measure positional coordinates of the points. Also, by measuring two different points on the center line, operators can measure the position and tilt of the axes of the cylinders. Furthermore, we developed a pile driving navigation system. Foundation piles are used for various structures, and their forms are generally cylindrical. Especially, although it is difficult to drive tilted pile foundations, their usage are expected to expand due to their high earthquake resistance. Yet, a method to accurately measure the tilts of piles has not been established. However, we proved that operators can obtain adequate accuracy to control foundation piles through the measurement experiment using this system. Using this system, the information of the pile is measured using a TS, transferred to a PDA, and displayed from the operator?s view of the piling machine.

Aug 1, 2013

By A. O. Dufresne

A Step which, it is believed, will prove extremely beneficial to the Quebec asbestos-mining industry was taken during 1931, when the asbestos mine operators of the Province assembled to work out a uniform method of naming the products of their mines. The outcome of several meetings was the drawing-up of a classification which defined, limited, and designated anew the numerous grades of asbestos marketed. It entailed no drastic departure from the existing processes of grading, nor any revolutionary changes in methods of testing, but aimed rather to perfect existing methods. The classification proposed has been accepted by all operators in the Province, who, from January first of this year, began introducing the new nomenclature. Unless one is conversant with the properties and mode of occurrence of chrysotile asbestos, with the unique milling methods devised for its recovery, and with the history of the development of their technique, he may not readily understand the basis of the new classification. For information on these and other data concerning the industry, the reader is referred to a recent publication, Chrysotile Asbestos in (Canada, by James Gordon Ross, issued by the Mines. Branch of the Department of Mines, Ottawa. The object of this paper is to present briefly some of the phases in the evolution of the classification of Canadian chrysotile asbestos, in the hope that the recent effort to standardize the marketable products of one of Canada's most important non-metallic mineral industries will open a field for discussion, fruitful in new ideas and constructive suggestions. The necessity for the grading of asbestos results fundamentally from the fact that the price per ton depends on the length of fibre. At all times in the history of the industry, the very limited available supply of the longer grades, as well as the requirements of the trade, have caused relatively very high prices to be paid for fibre over half an inch in length, while for the shorter grades the price decreases rapidly, and at a rate which bears no proportionate relation to the length of fibre.

Jan 1, 1932

By L. Kilburn

"A survey of 281 mineral exploration agreements examines the ratios among three ways that may be used to purchase an interest in a mineral property, viz: pay cash, pay shares and make future expenditures on the property.The dollar value of the future expenditures exceeds that of cash or shares by about nine times in most of the 110 agreements that contain cash-expenditure or share-expenditure components. Results suggest that cash and shares are treated about the same in terms of value.Buyers and sellers have opposing priorities for the way that they prefer to purchase a mineral property. These opposing priorities should give rise to a perceived 50:50 balance between cash/share payment and future expenditures to satisfy the idealized situation described by most definitions of fair market value (FMV). This balance between cash/share payments and future expenditures appears to be rationalized in negotiations to a FMV when expenditures are nine times greater than cash and/or payments.On this basis, it is proposed that the FMV of a property may be determined by aggregating the dollar amount of the cash/share payments plus one-ninth the dollar value of future expenditures, as set forth in the respective purchase agreement, and proportionately applying such aggregate to full property value."

Jan 1, 2005

By F. L. Wu

Based on the analysis of a sealed coal mine resulting from a fire-triggered explosion, limitations were discovered in the re-entry procedures used to reduce the size of the sealed area that were being applied during the process of re-opening the mine. The analysis of two re-opening plans in a mine using mechanical ventilation showed that the estimation of the degree of damage of two air doors close to the working face with the fire was key to the identification of the optimum mine recovery plan. The operation points of airflow and air pressure of the main fan under either the doors? damaged or intact conditions can be estimated through the use of a ventilation network simulation program. Starting the main fan for a short time period and measuring its operation points of airflow and air pressure allowed their comparison with the simulated values. This procedure provided a reasonable estimation of the degree of damage of the ventilation structures and more confidence in choosing a recovery plan. Through this process, it was possible to conclude that the two doors were still intact. Consequently, the final plan of installing a new main fan in the main decline, sealing the initial upcast shaft and unsealing the auxiliary downcast shaft, was proven to be reasonable at the mine site.

Aug 1, 2013

By R. Lowery

TODAY, man uses, at will, the land, the water, and the air to transport himself and his goods everywhere across the face of the world. He no longer thinks with wonder of the magic of conquering these elements - he takes his mastery of them for granted. He is, however, constantly striving to squeeze more and more efficiency from each mode of transport. Man's first method of transporting himself and his goods was, obviously, himself; then he acquired his first beast of burden - woman. Most other two-legged female animals carried their young around clinging to their fur. Human mothers were, generally speaking, furless and their offspring less 'Prehensile, and so slings and other trappings were invented to carry young children. Man's inventive genius soon adopted these devices for carrying other burdens, and for countless centuries woman carried all in order that man could walk unencumbered except by his weapons. Later other ?beasts of burden were trained and used, including dogs, horses, oxen, camels, etc. Man also discovered quite early that he could drag along the ground more than he could carry on his back.

Jan 1, 1956

By J. C. Underwood

"The wear performance of grinding balls under conditions of impact and abrasion is affected by their chemical composition and structure. The selection of appropriate analyses and heat treatments that will provide both abrasion and impact resistance takes into account the effects of certain elements on structure and harden-ability, as well as the over-all effect of composition and hardness penetration on the residual stress pattern developed through heat treatment. Direct quenching from forging temperatures substantially increases hardenability over that obtained in reheat-quench practices, and can be done without undue risk of damage to the ball provided that the harden-ability bears the correct relationship to ball diameter.Average volumetric hardness and percent hardened volume are convenient parameters for quantitatively expressing the response to heat treatment and indicating anticipated wear properties. A number of factors which can lead to reduced wear life as a result of material or processing problems are reviewed and illustrated."

Jan 1, 1959

By Shin-Kun Ryi

The world nowadays faces many challenges associated with excessive utilization of fossil, fuels, such as poor air quality and greenhouse gas emissions. Hydrogen appears to be an attractive alternative to the conventional, fossil, fuels with better energy efficiency and less environmental, impact. Pd and Pd-based alloy are the most often used membranes for hydrogen separation due to their superiority over other membranes. However, the stability of the commonly-used thin Pd-based composite membranes at high temperatures still, remains a big challenge. In this presentation, we will, report our progress on thin Pd-Ru alloy composite membrane by electroless plating high temperature applications.

Jan 1, 2010

By Ho-Sung Yoon, Jyothi Rajesh Kumar, Chul-Joo Kim, Sung-Don Kim

A recovery process for rare earths (REs) such as dysprosium and neodymium from the leach liquor of permanent magnet scrap (PMS) was developed. The two hydrometallurgical routes namely liquid-liquid extraction (solvent extraction) and selective stripping were implemented. The present study deals with the separation and recovery process development by using organo-phosphorous based extractant di-(2-ethylhexyl phosphoric acid (D2EHPA) as reagent for REs processing. Initial studies considered the influence of time on the extraction process, as well as pH and extractant concentration effects. This suggested the aqueous mechanism and separation factors played a role in process during development. McCabe-Thiele diagrams for extraction isotherms were developed. Counter current extraction (CCE) using various phase ratios influenced metals separation. Maximum loading capacity of the D2EHPA was determined. The loaded organic generated by the CCE process was water washed followed by a scrubbing process to remove the other metal ion from targeted metal. Finally, a stripping process was tested using various mineral acids.

Jan 1, 2015

By K. Hawboldt, J. E. Halfyard, C. Bottaro, I. A. Harrison

"The removal of elemental sulfur from leach residues derived from massive sulfide concentrates via hydrometallurgical routes has been demonstrated in a laboratory setting by converting water-insoluble sulfur to water-soluble polysulfides. The approach was applied to leach residue from Vale's nickel hydromet demonstration plant in Argentia, Newfoundland, which contained significant amounts of elemental sulfur. This technique offers an alternative treatment protocol for residues with a sulfur component not amenable to standard flotation/hot filtration processes. The practical considerations of a proposed flow sheet will be discussed including the impact of other sulfur species (e.g. thiosulfate and sulfides) and key process variables. INTRODUCTIONPresently, large scale elemental sulfur extraction from hydrometallurgical leach residue is performed by Teck Resources using a process of sulfur flotation followed by hot filtration (Chalkley et al., 1993). As mentioned, the technique proves viable for residues derived from specific concentrations - in this case zinc - whose residues constituency is primarily elemental sulfur itself. However, problems arise when this constituency is altered as happens when, for example, a mine containing one particular concentrate is mixed or replaced with a differing concentrate from a second mine. Such cases can often strain the effectiveness of current sulfur removal processes (D'Odorico, 2004). If hydrometallurgical residue containing elemental sulfur cannot be effectively treatment by flotation, the residue is stored subaqueously as is the case in some 'grass roots' hydrometallurgical plants (those not coupled with smelting operations). Hydrometallurgical processing of concentrates involving pressure leaching is becoming increasingly common throughout the mining world, the genesis of which can be found in research performed by Sherritt in Fort Saskatchewan since the 1950’s (Ozberk et al., 1995).The investigation of elemental sulfur removal by means other than flotation includes the uses of sulfide salts (NH3S or Na2S) effecting the conversion of hydrophobic elemental sulfur to hydrophilic polysulfides. The work of Kunda et al. (1974) and Olper et al. (2007) shows that elemental sulfur can be quantitatively removed from hydrometallurgical leach residue via the formation of a mixture of polysulfides."

Jan 1, 2012

By J. Doucet, C. Price

In an industrial setting, operational changes are continually introduced, driven by new technologies or changing economics. Because of day-to-day variability, quantifying the impact of these changes based on metallurgical performance requires long trial periods to achieve statistically significant results. Tools and techniques developed by the mineral processing group at McGill University have allowed for direct measurement of process variables (e.g., bubble size, gas and solid holdup). Two case studies are described where direct measurement techniques were used to evaluate: a) a new rotor stator mechanism; and b ), the introduction of a new frother type. Application of these methods has accelerated the evaluation of process changes and improved confidence in results.

Jan 1, 2009

By A. M. Bell

General Summary THIS paper attempts to describe in a preliminary and general manner the nature of certain copper discoveries now being developed by Gaspe Copper Mines, Limited, in Holland township, in the interior of the Gaspe peninsula. Some copper mineralization appears to have been known here at the time of the earliest French explorations, was rediscovered in 1921, and has been under intermittent development by Noranda Mines since 1938. In the last two years discoveries have enhanced the picture so that the deposit now promises to develop into one of the important Canadian copper producers. As ideas are constantly changing with continuing development, any picture given now is very partial and tentative and must be subject to future revision. The nature of these copper occurrences differs from others known in eastern America. In many respects they have unique features but they are most closely akin to some copper deposits found away from the intrusive rocks in the porphyry copper districts of the western United States. The most important orebodies are replacement deposits in a limestone horizon in which the ore gangue is converted to skarn. These lie at considerable distances from any known intrusive but seem to have been derived from a buried stock of granite that intrudes the sedimentary rocks of Lower Devonian age. This intrusive has produced alteration effects in the overlying rocks that may afford a key to locating other ore areas in the Peninsula.

Jan 1, 1951

By W. T. Robson

ONE of the problems encountered in any mine is the effect of increasing pressure manifested by increasing depth. Although the depth at which excessive pressure assumes serious proportion, and the manner in which it appears in underground workings, are influenced by a variety of factors, nevertheless the difficulty is present in all mines and its gravity increases with increasing depth. In the Kirkland Lake camp, as far back as seven years ago, mining had proceeded to depths sufficient to result in the formation of pressure great enough to cause violent disruption of masses of rock. It is proposed in this paper to deal with the effect of pressure caused by mining as observed at Lake Shore Mines, and to describe some of the methods which have been adopted to counteract it. There are many contributing factors in a study of the problem, and results vary widely in individual mines and in different localities. One feature common to all, however, is that there is ground subsidence, evidenced either by a gradual settling accompanied by crushing and shearing of the ore and wall-rocks, or the disruption of the ground surrounding the periphery of an excavation may take place suddenly, attended by more or less violent shattering of the rocks. Such violent failure of a mass of rock has been designated by the term rock-burst. The history of rock-bursts extends over a great number of years. They have occurred in some form or other in practically ali places where mining operations, at all but very shallow depths, have been carried out. Since the theoretical aspects of the subject have been dealt 'with at great length by capable and experienced writers (1), the present paper will give only a brief résumé of the theories propounded by those engaged in deep mining operations in various parts of the world.

Jan 1, 1940

By Adam Moore, Ryan Gillespie, Jarrett Quinn, Audrey Walters, Peter Radziszewski

"Vale Long Harbour Processing Plant (LHPP) was designed to process Voisey’s Bay nickel concentrate into finished nickel and associated copper and cobalt products. The plant includes a secondary grinding circuit comprising two Stirred Media Detritors (SMDs) operating in parallel. The ultrafine grinding circuit was designed to process concentrate at a rate of 33 t/h and produce a ground product (P80) of 20 µm to feed the leach circuits. Start-up of the grinding circuit at LHPP was undertaken in December 2014.The objective of this paper will be to describe the design, commissioning, start-up and performance of the secondary grinding circuit with a focus on the two Metso SMD-355-C mills. Following a brief overview of Vale’s LHPP and the SMD technology, the paper will review the design of the SMD secondary grinding circuit from lab tests through to scale-up performance prediction. This will be followed by the results of circuit commissioning outlining some of the issues raised and addressed after which SMD performance will be outlined. Specifically, the SMD circuit grinding performance will be examined since start-up which will include the effect of media size and wear on grinding. Furthermore, impeller wear will be examined by determining initial “shear volume” and worn “shear volume” as well as its effect on mill power and the means to maintain it. The paper closes with a discussion on grinding performance."

Jan 1, 2016

By A. Idegami, M. Imamura, S. Heguri, Y. Ozaki

"Nickel powder can be produced by the reduction of a nickel ammine complex solution by hydrogen at high temperature and pressure. To minimize the deposition of fine nickel on the surface of the reactor and other equipment, seed crystals are added to the initial solution to promote nucleation of the nickel powder. Such seed crystals catalyze the precipitation of the nickel particles on the surface of the seed and enhance grain growth. In this study, nickel nuclei were precipitated by the addition of a polymer to the nickel ammine complex solution, resulting in the production of nickel powder. Thus, we herein propose a model that explains the effect of the polymer in the precipitation of nickel nuclei.INTRODUCTIONNickel powder is commonly produced via a hydrometallurgical process from the hydrogen reduction of a solution containing a nickel ammine complex at high temperatures and pressures, and this process was commercialized in the 1950s by Sherritt Gordon (Sherritt International, Canada, Benson & Colvin,1973; The Staff, Research and Development Division, Sherritt Gordon Mines, Ltd., 1958).In the above transformation, upon the injection of hydrogen gas into the solution, nickel is reduced as outlined in Equation(1), ultimately resulting in the production of nickel powder.Ni(NH3)nSO4+ H2?Ni+ (NH4)2SO4+ (n-2)NH3(n:2–6)(1)In this process, seed crystals are added to the reactor to suppress the precipitation of fine nickel (scaling) and to enhance nickel reduction (Benson & Colvin, 1973; Mackiw, Lin & Kunda, 1957). More specifically, iron sulfate and a small amount of dispersant polymer are added, which leads to the formation of nuclei. Upon subsequent hydrogen reduction, the reduced nickel can then be deposited on the nuclei, allowing nickel particle growth to take place. However, this results in iron contamination in the final nickel product, and so the use of pure nickel as a seed crystal is desirable to produce high quality nickel powders."

Jan 1, 2017

By Tong Guan, Guangqin Fu, Lihong Deng, Yuanlin Chen, Xiaotong Zhou

"In natural world, some kinds of scheelite minerals are rich in molybdenum. Molybdenum exists in the crystal lattice of scheelite in the form of isomorphism, and the content of MoO3 varies from 2% to 10%. As a result, the flotability of seyrigite (scheelite with molybdenum) turns to be weaker. One seyrigite mine, which has been built for 3 years,still could not produce qualified seyrigite concentrate due to the weak flotability of seyrigite (Mo-bearing scheelite) in raw ore. In our experimental research, through adopting new seyrigite collector TA-3 and advanced mineral processing technology, the seyrigite concentrate with a grade of 65.62% WO3 at a recovery of 87.47% was obtained for the raw ore containing 0.19% WO3 and 0.074% Mo. By applying the new technical achievement, for the raw ore containing 0.272% WO3, the seyrigite concentrate assaying 68.03% WO3 with a recovery of 77.56% was obtained in industrial production.INTRODUCTIONIn natural world, some kinds of scheelite minerals are rich in molybdenum. Molybdenum exists in the crystal lattice of scheelite in the form of isomorphism, and the scheelite is changed to be seyrigite (Ca[(W,Mo)O4]) (Ma, Bian, & Wang, 2013). The content of MoO3 in seyrigite varies from 2% to 10% usually, the content of MoO3 in some of the seyrigite even reaches 34%. The flotability of seyrigite is weak (Zhang, 2007), and the seyrigite is difficult to be recovered by flotation with common collectors and regulators. One scheelite mine in Anhui China, which is a skarn type seyrigite mine, has not produced qualified concentrate yet since 3 years it has been built due to the limit of beneficiation technology. Therefore, it is necessary to conduct research on the collectors with high efficiency and developing advanced processing flow for this kind of ore."

Jan 1, 2016