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By P. Clinton Milne

Uranium mines in Washington State include the producing Midnite and Sherwood mines and several mined-out deposits, the most productive of which was the Daybreak mine. The Midnite mine is generally classified as a hydrothermal deposit consisting of tabular orebodies in Precambrian pelitic and calcareous metasedimentary host rocks. The host rocks occur as roof pendants in a Cretaceous porphyritic quartz monzonite intrusive; the quartz monzonite averages 12 ppm U308 The uranium deposit appears to have undergone a complex genesis, involving a series of depositional and enrichment stages. The Sherwood uranium deposit, approximately 4 miles south of the Midnite mine, occurs near the bottom of a basal Late Cretaceous to Paleocene arkosic conglomerate. The conglomerate lies nonconformably on the porphyritic quartz monzonite that is associated with the Midnite deposit. The Sherwood and Midnite uranium deposits may have had a similar genetic history linked by a common uraniferous pluton source, ground-water action, and/or leaching of uranium-rich ash flows from now-eroded, overlying, Eocene volcanics. The Daybreak deposit, in northeastern Spokane County, consists entirely of secondary uranium mineralization (metaautunite) in a quartz monzonite pluton. Mineralization is confined to a low-angle fault zone and is most highly concentrated at the intersection of primary and secondary shears. Both hydrothermal and ground-water origins are feasible. Besides the Midnite-Sherwood area, 14 other areas in the western Okanogan Highlands physiographic province and Cascades region have favourable characteristics for uranium potential. Criteria include the existence of uranium occurrences, Tertiary basin sediments with intercalated volcanic and volcaniclastic rocks, favourable geochemical data, alkaline plutons associated with uranium occurrences or borders of Tertiary basins, and structural controls.

Jan 1, 1979

By K. Jomoto, H. Majima

"Experimental work has been attempted to find a useful criterion of comminution which can be determined simply in a laboratory. The suitability of the ratio of the square of tensile strength to Young's modulus, St2/E, previously derived from the theory of elasticity as a criterion of comminution, was examined measuring tensile strength, Young's modulus and critical height for drop-weight impact of five different rocks. However, satisfactory correlation between St2 /E and critical height has not been obtained, suggesting the necessity of further experimental verification of the representative value of Young's modulus of rocks. The plot of St2 vs. critical height, however, shows one-to-one correspondence, and this finding suggests that St• may be a useful criterion of impact crushing. Also, a close relationship was observed between st• and the energy index for tumbling mill grinding of •the sample rocks. It is confirmed from these findings that the quantity St• is a useful criterion of comminution of rocks, not only for impact crushing but also for tumbling mill grinding. As shown in the experimental part of this paper, the determination ol St with irregularly shaped specimens is simple."

Jan 1, 1972

By J. Dionne

"Next to the actual mine of Les Explorations Muscocho Ltée in Montauban, Quebéc, you could find a total of 364 000 tons of flotation tailings assaying 1.4 Au g/t et 82 g Ag/t to the south of the municipality. This tailings pile is what is left of previous operations. Preliminary leaching tests on these tailings in laboratory columns gave interesting results which led to tests in larger columns in 1984 and to a pilot test on a 750 ton heap in Montauban during the summer of 1985.This paper briefly describes the columns tests performed at the Centre de Recherches minérales and the heap leaching test designed and conducted by SOQUEM in Montauban. It also presents the results obtained.RESUMEPrès de la mine actuelle de Les Explorations Muscocho Ltée à Montauban, Quebéc, se trouvent, au pied du village, 364 000 tonnes de rejets de flottation titrant environ 1,4 g Au/t et 82 g Ag/t. Ce tonnage de rejets représente ce qui reste de l'opération des anciennes mines de Montauban.Des essais préliminaires de lixiviation en colonne sur ces rejets ont donné des résultats encourageants. Ils ont été suivis en 1984 par des essais en colonnes plus volumineuses et par un essai pilote à Montauban en 1985 sur une pile de rejets de 750 tonnes.Ce te x te donne une brève de script ion des essais en colonne effectues au Centre de Recherches minérales et de l’essai pilote planifie et exécute à Montauban par SOQUEM. Il présente les résultats obtenus."

Jan 1, 1987

By M. C. Bétournay, J. E. Udd

"The Mining Laboratories of CANMET are the principal federal government vehicle for the delivery of mining research in Canada. With research being performed at five locations, which are mostly mining communities, the laboratories are in close proximity to the industry which they serve.The Mining Laboratories have three principal roles: (1) to support government in its development of policy; (2) to aid industry in the enhancement of productivity; and (3) to improve the health and safety of Canadians,both in the workplace in mines and around abandoned mine sites.From 1994 to 1996, CANMET’s mining research was re-focused into four programs. These are: (1) Underground Mine Environments; (2) Mine Mechanization and Automation; (3) Ground Control, and; (4) Coal Mining Health and Safety.In this paper, the authors outline the work of the Mining Laboratories and also identify the areas considered to be primary targets for future mining health and safety research in Canada."

Jan 1, 1997

By H. Warren Newcomen

The southwest wall of the Lornex Pit at the Highland Valley Copper mine has been experiencing slope displacements since 1978. Measures to manage the displacements on previous pushbacks have included stepping out, scheduling pushbacks to unload the crest of unstable areas, slope dewatering and mining with intensive slope monitoring. The final pushback on this wall is currently being mined and substantial modifications to the slope geometry could prove to be uneconomic. As a result, a campaign of surface water collection and diversion, horizontal drainhole drilling and deep well drilling is currently underway to maintain an acceptable degree of stability to the end of mine life. The various factors contributing to instability, including engineering geologic controls, rock mass strength, and surface and groundwater hydrology are presented. Movement trends, displacement magnitudes and stability analyses results are also discussed.

May 1, 2002

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005

By C. M. Diaz, P. J. Mackey

Since its inception, in 1987, the Copper-Cobre series of conferences has established itself as the prime world forum for discussing advances in copper process metallurgy, in particular copper sulfide smelting, copper recovery by leaching and electrowinning and copper electrorefining. All copper producing countries have actively participated in the pyrometallurgy symposia held in the framework of these conferences. In 1999 and 2003, the close to 100 pyrometallurgy papers that were presented had to be accommodated in two volumes. In the present paper, the authors firstly provide a brief historical sketch of the Copper-Cobre conferences and then focus on providing a retrospective look at the dramatic changes that have taken place in copper smelting in the last few decades, primarily as discussed in the Copper-Cobre and precursor conferences pyrometallurgy proceedings. Topics include: the development of autogenous, increasingly more intensive, environmentally sound and energy efficient smelting processes; significant improvements in Peirce-Smith converting practice and at the same time the commercialization of alternative continuous converting routes; the consequent expansion and modernization of smelters; the increasing compliance with strict government environmental regulations in most copper producing regions of the world; the realignment of the copper smelting industry throughout the world; and trends in copper smelting R&D. A look at the future closes these reflections on the contribution of the Copper-Cobre conferences to the advancement of copper smelting technology.

Jan 1, 2007

By Mark Sherman

"One of the main functions of a process technology and engineering services provider is to select grinding equipment that will meet the client’s throughput rate target. Prudent risk mitigation strategies would suggest that throughput rate estimates be cross-checked using a variety of techniques.Whilst some comminution circuit designers have estimated specific energy requirements via the manipulation of the Bond specific power equation e.g. Barratt’s Grindpower and OMC’s FSAG approach, other designers have opined that the Bond Indices have no role to play in the calculation of SAG mill specific power. As a result, they have developed their own specific energy estimating methodologies, e.g. SMCC’s Drop Weight based power methodology, SPI, SAGDesign, etc. Each method has its supporters and its critics.The challenge facing the engineering provider is how to nominate an SAG mill based circuit throughput rate estimate when faced with significantly disparate specific energies calculated by the different methodologies. This challenge is exacerbated via the continuing evolution of contemporary circuit configurations such as two stage pebble crushing some of which incorporate HPGR technology as the second stage of pebble crushing.The methodology presented in this paper shows that the Bond Indices are an excellent tool for estimating the specific energy requirements for SAG mills in SAB, SABC and SSS circuits. The method accommodates primary crushed feeds, partial and or fully secondary crushed SAG mill feeds, and emulates the impact of pebble crushing on SAG specific energy. As a result, the new Bond Index based method has provided an additional tool for increasing Fluor’s confidence when predicting SAG mill based circuit throughput rates. Based on this outcome, the author proposes that the decades old conundrum of using Bond Indices to calculate SAG specific energies for SAG mill based circuits has been solved."

Jan 1, 2012

By G. M. Hughes, R. W. Dunn

"AbstractCurrently installed an analogue instrumentation devices at Sherritt 's Ruttan Concentrator control. and/ or measure mill tonnages, grind, pH, density , some reagent and slurry flows, and cell levels. On-stream analysis is used to assay the main process streams. The history of development of process control is reviewed from startup to the present stage of selection of a process control computer. A pragmatic approach has been taken to process control to ensure compatibility with the needs and resources of Ruttan. Emphasis is made of the need to have the mill performing well from a mechanical and instrumentation point of view and to have opera tor acceptance of the computer through training. Plans for the computer phase to achieve these objectives are outlined.IntroductionTHE COPPER-ZINC OREBODY at Ruttan Lake was discovered by Sherritt exploration personnel in 1969 and by mid-1973 a 10,000-tpd mine and concentrator were in operation. After a typical startup period , the major mechanical problems in the crusher and concentrator have been resolved. Metallurgical performance is now up to standards forecast in the feasibility study.The cost of the original instrumentation installations, including an on- stream analyzer, was about one million dollars or 4% of the cost of the milling complex. Although there was no intention of using a process control computer until the plant was operating smoothly, it was understood that all instrumentation was compatible with .a computer, but this did not prove to be correct. This paper cover s the development of the instrumentation loops to date and the control strategies that will eventually be implemented through a process control computer."

Jan 1, 1977

By A. H. C. A. Zimmerman

WE have just heard what must be regarded as a thoughtful, constructive and somewhat painful analysis of the financial function of our industry. While thinking about this, it is interesting to reflect on the conditions which have stunted the growth of the financial side of our affairs. Mining must be regarded as a wealthy business. •while immeasurable grub takes and development budgets have been lost, there can be little argument that a productive ore-body nearly always produces the type of wealth that breeds some extravagance. I recognize that this statement can be attacked from many sides, but an historical comparison with a commercial enterprise involving similar investment will demonstrate what I mean. However, these old times are be-ginning to disappear for a variety of reasons. High amongst these are: ( l) Increased costs of exploration. (2) Remoteness of many new finds. (3) Fixed or declining metal prices (particularly when expressed in constant dollars). ( 4) Constant demands for higher wages.

Jan 1, 1962

By Andy Fortin, Jeet Basi, Simon Hille

Goldcorp’s Eleonore mine is situated in Ell Lake area in the northeastern part of the Opinaca reservoir in the James Bay region of Quebec. The design of the 7000 t/d process plant includes crushing, grinding, bulk sulphide flotation, separate concentrate and tails leaching and detoxification circuits and residue handling. Detoxified flotation tails are thickened and filtered. A portion of the filtered tails are blended with the thickened detoxified sulphide concentration for paste backfill. The remaining filtered tails are trucked to the waste management facility. This presentation will describe the challenges faced with the commissioning and subsequent ramp-up of the flotation tails filter plant and the successes achieved by the multi-discipline team at Eleonore.

Jan 1, 2016

By Christopher W. Corti

A major aim of the GOLD 2003 conference, is to promote new gold related science and technology with a view to developing new useful industrial applications for gold. Current industrial uses have provided a steady annual industrial demand for gold of around 350-400 tonnes in recent years, the bulk of which is centred on electronics applications, with dental uses constituting the second largest application. However, there is good reason to believe that whilst gold will continue to play a major role in these sectors in the future, substantial growth of demand is not anticipated. Increased industrial demand for gold is only likely to come through the emergence of new applications, probably most significantly in five broad market sectors: ? Pollution and emission control technologies, including fuel cells. ? New uses for gold in advanced electronics, electrical systems and devices. ? Chemical processing of a range of bulk and speciality chemicals, using gold based catalysts ? Advanced coatings exploiting the novel properties of gold, particularly in nanoparticulate form. ? New biomedical uses for gold including medical treatments, drugs, implants, sensors and devices. There is cause for optimism that many new applications for gold could emerge in these sectors over the next decade and that this will lead to a substantial growth in demand for gold. It is clear that many of these new opportunities will be based on a chemical approach to synthesis of useful products rather than what has historically been a materials or mechanical approach. To turn this expectation into reality requires sustained support of R & D and a determination to exploit this new science and technology into viable commercial applications.

Oct 1, 2003

By G. P. van Greunen

"The rehabilitation of underground excavations has been undertaken as long as mining has existed. The conventional methods have proven to be dangerous, time consuming and expensive. During the construction of Styldrift Mine at Royal Bafokeng Platinum several vertical and horizontal excavations had to be rehabilitated. With a zero tolerance attitude towards working in unsafe conditions, together with a non-negotiable timeline to construct and ramp up the mine, the project team could not rehabilitate these excavations using conventional methods. This paper details the approach used to rehabilitate excavations using remote methods and how it was adapted to suit varying operating conditions and requirements - ensuring that no person ever entered an unsafe excavation before it was fully rehabilitated and safe. INTRODUCTION Styldrift Mine is an expansion project of the Royal Bafokeng Platinum group. It is located in South Africa in the North West Province some 10 km south of the Sun City resort (Figure 1). The mine consists of a twin shaft system (Main Shaft and Services Shaft). Capital construction of the shaft and associated infrastructure started in 2009 and is projected to be completed during 2020. The designed steady state production capacity of the shaft is 230 ktpm of Merensky ore. Production ramp-up commenced in 2017 with steady state production set to be achieved 36 months later in the fourth quarter 2020.Merensky Reef was intersected at a depth of 600 m below surface and the shaft design has a mean mining depth of 630 m. The project was approved for execution in 2008 on the basis of a suitable mine design and bankable feasibility study. One of the main excavations that required rehabilitation was an underground reef silo, Silo 4. It is a key piece of infrastructure on the critical path to allow steady state production at Styldrift Mine to be achieved. During construction excessive scaling within the silo along its 64m length necessitated urgent rehabilitation to be able to meet the ramp-up schedule. The criticality and urgency of these excavations prompted the project team to reduce the risk of failure while ensuring safe and cost-effective rehabilitation. This paper will focus on the rehabilitation of Silo 4 while capturing the essence of the learnings of all the excavations that were rehabilitated remotely."

Jan 1, 2019

By W. E. Davies

"This paper is the sequel to that on Developments in Sintering Efficiency delivered by Davies and Mitchell at the International Ore Dressing Congress, Stockholm, 1957. Attention is drawn to the fundamental concept of sintering as a heat transfer process, in which the ignition heat is continually transferred onward through the bed as a heat wave. By its passage, this heat initiates endothermic 'changes, such as carbonate decomposition, whose energy requirements are supplied by the combustion of the fuel contained in the bed.Ideally, the heat wave should be generated by the ignition hood followed by the pre-heating of the incoming air. The fuel content of the bed should be no more than the theoretical quantity needed to balance the endothermic changes. In practice, the heat wave is seriously short of energy and this is offset by excess fuel in the bed. As a result, sinter quality suffers, more return .fines are produced, and fuel is wasted, a loss of efficiency which could be avoided if the fundamentals of correct ignition were more widely appreciated.Sintering speed, otherwise heat wave velocity, is a function of the rate at which the incoming air acquires .heat from the cooling sinter and imparts it to the unburned feed below the combustion zone. It is thus a function of rate of air flow and so depends on bed permeability>. Ways of• improving and maintaining permeability at the maximum consistent with thorough sintering are discussed, particular reference being made to taconite concentrates. The possibilities of recrystallizing refractory ores into forms more amenable to physical concentration techniques by sintering are visualised, very little expenditure on heat energy being required when the process is operated near the ideal conditions."

Jan 1, 1960

By Malcolm Scoble, Jean-Marc Robert, Luciano Piciacchia

"An approach to the in situ testing of mine backfills is outlined. It has been developed to provide a measure of the effective strength and stiffness of such materials after placement in stopes. This paper is based upon recent field studies undertaken at five Quebec mines. Details of the selected instrumentation, supporting equipment and testing procedures are reviewed. The mechanical behaviour of the backfills is reported and related to their physical properties. This approach represents an economical, simple and reliable means to assess the mechanical characteristics of backfill materials as an aid to both mine design and placement quality control. IntroductionDevelopments in backfill and mining method technology are creating a pressing need to develop effective techniques for characterizing the physical and mechanical properties of backfill in situ, rather than relying on traditional laboratory testing. The development of bulk mining methods is creating the requirement to more fully understand the nature of exposed fill faces to design for stability in pillar recovery operations. Other backfill technological developments currently receiving widespread attention are high density placement and the use of alternative additives to Portland cement. In Canada, U.S.A. and South Africa attention is also being placed on employing backfill to alleviate rockburst hazards(1,2.3l. In situ testing offers the potential to measure the geomechanical properties of backfill once placed in stopes , in order to assess its actual role in pillar recovery and ground support. Similarly, it offers the ability to provide some quality control during backfill placement. This role is seen as becoming increasingly important with the growing recognition of the need to pay greater attention to the mode of placement, which governs segregation and variation in the properties actually achieved by the backfill after placement."

Jan 1, 1987

By E. V. Neelands

THE Canadian Malartic mine is in Western Quebec, about fifty miles east of Noranda and forty miles south of Amos on the Canadian National railway. The recently constructed branch of the railway from Rouyn to Senneterre passes half a mile north of the mine. HISTORY he property was discovered in 1923 'by St. Barbe Sladen, H. S. Kennedy, and J. C. Carroll, who were prospecting for an Ottawa syndicate and found gold in a small quartz vein near the present workings. Five claims were staked and were optioned to an exploration company, who allowed the option to lapse after surface sampling and diamond drilling eighteen holes. Some months later, the property was sold to Malartic Gold Mines, Limited, who carried on development until 1929. A vertical shaft was sunk and exploration work done on three levels, supplemented by diamond drilling 16 surface holes and 62 underground holes. The work indicated that the important ore occurred in two silicified.zones in schisted greywacke which intersected west of the shaft and were believed to be controlled by a drag-fold. The ore grade was not considered sufficiently favourable to war-rant an operation, and work was terminated. With the advance in the price of gold to $35 per ounce, interest was revived and a new Company, Canadian Malartic Gold Mines, Limited, was incorporated for further development. The shareholders of the old Company accepted a new position under which their interests were protected, and sufficient treasury shares were optioned to Ventures, Limited, and Sudbury Basin Mines, Limited, to provide funds for further exploration of the prop-erty to determine whether, under the new economic conditions, profitable operation would be possible, and, if advisable, to provide the equipment for production. Additional claims were acquired, bringing the total area up to 1,029 acres.

Jan 1, 1939

By Mostafa Benzaazoua, Bruno Bussière, Philippe Poirier, Denis Bois

"Environmental desulphurisation is an attractive alternative for the management of acid generating tailings. Non selective froth flotation is the most commonly used method to produce desulphurized tailings, as shown from many previous works (McLaughlin and Stuparyk, 1994; Bussière et al., 1995; 1998; Benzaazoua et al., 2000a,b; 2002). This process can reduce the volume of problematic tailings to manage, by making a sulphide fraction concentrate. The desulphurized tailings can then be used as a moisture retention layer in a cover with capillary barrier effects to prevent acid mine drainage.In this paper, the authors present the results from different laboratory and pilot scale flotation tests which confirm that low sulphide, non-acid generating tailings can be produced by froth flotation. It is also demonstrated that the sulphide concentrates obtained from desulphurisation, when mixed with binders gave good long term results in terms of mechanical behaviour, thus demonstrating that the sulphide fraction can be used for paste backfill material. From previous work (Bussière et al. 1998, 1999) on the evaluation of the operating and capital costs of the desulphurisation process for different ore types, the use of desulphurized tailings to create a dry cover was then studied for several scenarios. The desulphurisation process was compared with other technologies (underwater disposal, engineered soil cover) currently used to prevent acidic drainage (AD) for a new mining operation and the advantages and disadvantages of desulphurisation are presented as well as the costs of this method of AD prevention.INTRODUCTIONThe principal environmental problem of the mining industry today is the generation of acidic drainage (AD) resulting from the natural oxidation of the sulphides in mine tailings. This phenomenon involves the generation of acidity which increase the amounts of toxic metals in the waste water released into the environment by a mine. The environmental impact of the AD has been described in detail in previous work (e.g. Down et Stocks, 1977; Ritcey, 1989; Gray, 1997; Ripley et al., 1996; Aubertin et al., 2002)."

Jan 1, 2004

By C. Edwards

"The processes for rare earth (RE) extraction include the decomposition of RE ore concentrate minerals, and the concurrent or subsequent leaching of the rare earth elements (REEs) from the decomposed minerals. Ore beneficiation concentrate can be decomposed by, for example, acid roasting, caustic cracking, and chlorination. The REEs can be selectively extracted. The nature of the REE extraction process depends on the concentrate mineralogy and the targeted products. Based on the experience of the Saskatchewan Research Council (SRC) in RE processing, this paper reviews REE extraction from the major RE minerals, including bastnaesite, monazite, xenotime, ion-adsorption clay, allanite, cerite, and eudialyte. An update on the development of RE extraction processes is also provided.INTRODUCTIONRE processing usually involves two operation stages, physical processing and chemical processing. Physical processing, also known as ore beneficiation, separates the RE minerals from gangue minerals to produce an RE mineral concentrate. Chemical processing, which includes extraction and separation processes, converts the RE mineral concentrate to an RE compound which is either an end product or an intermediate product for the subsequent production of individual REEs or other compounds. The RE extraction process uses one or more reagents to decompose the RE minerals and to leach the REEs into solution. The RE separation process uses solvent extraction, ion-exchange, or chemical precipitation to produce either rare earth oxides (REOs) or individual REEs. The authors have previously reviewed RE ore beneficiation processes (Zhang & Edwards, 2012). This paper focuses on extraction processes for a variety of RE minerals. Table 1 gives the chemical compositions of the RE minerals mentioned in this paper. The varieties of RE extraction methods use many different reagents. These reagents are mainly inorganic acids, alkalis, salts, and chlorine gas. The commonly used acids include sulfuric acid (H2SO4), hydrochloric acid (HCl), and nitric acid (HNO3). Sodium hydroxide (NaOH) and sodium carbonate (Na2CO3) are the most common alkalis. Salts include ammonium sulphate ((NH4)2SO4), ammonium chloride (NH4Cl), and sodium chloride (NaCl). HCl is normally used to extract RE from silicate ore minerals such as allanite and gadolinite. The alkalis and H2SO4 are mainly used to leach REs from phosphate ores minerals like monazite and xenotime. The carbonate ore RE minerals such as bastnaesite can be treated using either acids or alkalis. HNO3 is mainly used to leach eudialyte and apatite. The extraction of REs from ionadsorption clay deposits uses salt solutions. Chlorine gas (Cl2) is exclusively used in the RE chlorination process which can be used to treat any RE minerals."

Jan 1, 2012

By Celine Y. Zhang, Chloe J. Feng, Charles Q. Jia, Donald W. Kirk

Oil sands petroleum coke (OSPC) is a by-product of coking - a high-temperature process that converts the mined bitumen to the synthetic crude oil (SCO). For every barrel of the SCO produced, about 20 kg of OSPC are generated. Over 70 million metric tons of OSPC have been produced and stockpiled as a result of the development of oil sands industry in the past few decades. Unlike conventional petroleum coke, OSPC has uniquely high impurity contents, particularly sulphur (~ 7 wt%) and metals (e.g. vanadium at ~0.15 wt%), which has hindered its large-scale applications as a solid fuel. Vanadium is a valuable metal that is widely used as an alloy for strengthening steels. The stockpiled OSPC contains about 100,000 tons of vanadium, while the world’s production in 2013 was only 75,600 tons. At the current price of $25US/kg, the OSPC-bound vanadium represents a total value of $2.5 billion US dollars. In this work, we investigate the technical feasibility of extracting vanadium from OSPC. The work focuses on the characterization of vanadium in OSPC and the conditions for effective extraction of vanadium from the OSPC.

Jan 1, 2015

By W. T. Martson

ABSTRACT Sooner or later, every producing mine faces the question of fill. This paper invites consideration of mill tailings as an economical, efficient, and quantitatively adequate source of such fill. Some of the advantages, disadvantages, methods of utilization, and methods of treating mill tailings for sand recovery are covered. ADVANTAGES AND DISADVANTAGES OF SAND FILL DISREGARDING economic com-promise, that material which supports the greatest applied load with the least compression is the best choice for fill. Table I, reproduced from U. S. Bureau of Mines Bulletin 60, is offered as evidence of the adequacy of hydraulically placed sand. Table II gives the results of tests made in an effort to determine the reason for the difference between load hearing qualities of dry-placed and hydraulically-placed sand. From these, it would appear that hydraulic placing gives a denser initial packing, with corresponding higher, and faster development of, load bearing qualities. Assuming this to be true, then if sand from mill tailings can be placed underground economically, it is the superior fill material. Table III summarizes cost data available. The most cursory glance through the available references (2, 5, 6, 7, 8, 9) will show .that the major benefit from the adoption of sand fill is a decrease in the non-productive fill ?cycle of a working place. This, it is estimated, increases the output of an individual stope by from 25 to 50 per cent. The advantage of reducing the number of required working places for a constant daily production is obvious.

Jan 1, 1951