Search Documents

By Steven Aiken

The East Boulder Mine located in Montana, U.S.A. utilizes snowmaking to assist with mine water treatment for nitrogen removal. Nitrogen species, including ammonia, are common contaminants in mine water from underground mining operations. Snowmaking provides secondary treatment of nitrogen during the winter due to the chemical and physical processes that occur during snowmaking, in the snow pack and in the snowmelt. The primary processes include atomization, evaporation, sublimation and volatilization. The snowmakers also provide secondary treatment for nitrogen removal when used as evaporators and/or land application units during the summer. In 2002, the snowmaking process was successful at reducing total nitrogen in the mine water by up to 87%. If additional losses due to soil and root zone processes are included, total nitrogen reduction would increase to between 87 and 97%. Snowmaking is an effective nitrogen reducing treatment method during the winter when other treatment methods such as land application cannot be used.

May 1, 2004

Arguably the SMC Test® has become the most popular laboratory hardness test in the world with over 17,000 tests having been completed to date, covering over 650 different ore bodies. It is now routinely used in design, optimisation and orebody profiling projects. The test is unique in that from relatively small amounts of drill core it simultaneously provides parameters that are used in simulation modelling of AG/SAG and crushing circuits as well as work indices that are used in power-based equations for predicting the specific energies of AG/SAG/Crushing and HPGR circuits. The very large data base that has been accumulated has provided the opportunity to study the differences in variability from deposit to deposit. This paper describes and discusses the trends that have become apparent from the study of this data base. Recommendations for appropriate selection of sample numbers are also made which are based on these trends.

Jan 1, 2012

By A. Suzue, T. H. Okabe, Y. Taninouchi

Methods for the physical separation and enrichment of platinum group metals (PGMs) from autocatalyst scrap were studied in order to develop an environmentally friendly and efficient recycling process. In general, an autocatalyst has a honeycomb-structured ceramic substrate that is coated with a catalyst layer containing platinum (Pt), palladium (Pd), and rhodium (Rh). Therefore, physical separation of the PGM-containing catalyst layer directly from the ceramic substrate is favorable for upgrading the autocatalyst scrap. In this paper, the authors present a scrap-upgrade process consisting of electroless iron plating and magnetic separation techniques. Iron was plated on the surface of a catalyst sample used to represent an autocatalyst, which was then crushed and magnetically separated. The Pd in the catalyst sample was successfully extracted and concentrated in the magnetic powder. Under certain conditions, the process increased the Pd concentration by a factor of 4 and recovered 89% of the Pd in the autocatalyst sample.

Jan 1, 2014

By Zhigao Xu, Ruan Chi, Zhenyue Zhang, Yaoyang Ruan, Zhengyan He

Thorium is frequently the main radioactive element in rare earth ores and is a resource that can potentially substitute for uranium. Thorium must be separated from rare earths in order to obtain products with low radioactivity. There are abundant resources of thorium in the rare earth ores in China, especially in Baiyunebo mixed ores. As an associated element coexisting in rare earth ores, thorium is, or can be, separated from rare earth concentrate, iron concentrate, as well as from waste water and slag to achieve recovery of thorium. The methods of separation include ion exchange resin, liquid-liquid extraction, and liquid-solid extraction. TBP extraction has been the main method applied to separate thorium by domestic and foreign scholars. This paper presents a comparison of different processes for the separation of thorium from rare earth ores, especially Baiyunebo mixed ores, single bastnaesite and monazite ore, and provides suggestions for the future recovery of thorium resources.

Jan 1, 2014

By K. P. Plucknett, Z. Memarrashidi

WC-Co ‘hard metals’ are widely used in a variety of industrial applications due to their resistance to abrasive wear, in addition to their high hardness and toughness. However, in contrast to their mechanical properties, the corrosion response of these materials is relatively poor. In the current work the corrosion mechanisms of two WC-Co cermets are analysed, with 10 and 30 vol. % of the Co metal binder, in a 3.5 wt.% NaCl aqueous solution. The assessment of corrosion involved a variety of electrochemical measurements, including open circuit potential, potentiodynamic polarisation and cyclic polarisation, together with systematic analysis of the post-corrosion solution chemistries using inductively coupled plasma optical emission spectroscopy. The corrosion potential and current density were determined, following Tafel extrapolation, allowing the calculation of the corrosion rates. It is demonstrated that continuous dissolution of the cobalt phase occurs during corrosion, which is a result of poor cermet passivation behaviour, and this response increases with the amount of binder in the cermet.

Jan 1, 2015

Abstract: ?The paper will review the perspective of Scotia Capital on financing mines, mining projects and mining companies in today's world of major increases in commodity prices, increases in capital and operating costs, shifts in foreign exchange rates, and increasing scrutiny of mining's social license ?Focus on debt financing alternatives Key Assumptions: ?Assume financing a mining asset (i.e. not an exploration play) ?Exploration is generally financed with equity ?private placements or public offerings on an idea

May 1, 2006

By Huan-Qiang Zhang, Gang-Hai Huang, Yu-Yong Jiao, Fei Zheng, Zhang. Xiu-Li

An efficient and accurate three-dimensional (3-D) contact detection algorithm is of vital importance in large-scale computing of discontinuous deformation analysis. The contact detection algorithm takes up a large proportion of the whole calculation time because of the increasing calculation number in three-dimensional case. For block systems which consist of convex polyhedrons, the efficiency and accuracy of the contact detection algorithm is a great challenge. The presented contact detection algorithm in discontinuous deformation analysis (DDA) method is carried out in three phases: the global neighbour searching, the local contact type searching and the contact transferring. A contact detection algorithm for 3-D DDA is presented with some improvements on the three phases. A grid-based global neighbour searching algorithm is used to eliminate unnecessary neighbour blocks to the exact number. The local contact type searching includes two steps. In the first step, the common plane method is used to determine the contact type between convex polyhedrons. In the second step, the contact pairs detected by the common plane method are divided into four basic types. In the third phase, the four contact types are transferred into two basic contact types, vertex-to-face contact type and edge-to-edge contact type, which are managed in a uniform procedure. Three verification examples are calculated, the results show that the proposed algorithm based on the three contact detection phases is robust and efficient.

Jan 1, 2015

By J. F. Magee

THERE is nothing new about drag-line dredging for placer gold. The use of the separate unit for excavating preceded the large barge with bucket-line excavator mounted upon it, which has developed to a high state of perfection through use in every part of the world. But at present there is a vogue for a small, inexpensive plant to work economically the shallower gold gravel deposits that the bucket-line dredges do not work. The dragline dredge consists of the drag-line excavator, on caterpillar mounting on the edge of the dredging pond, which feeds the gravel to the washing plant, mounted on a floating barge in the pond. There have been more than twenty-five such plants built and operated in central and northern California and an unknown number in other States. There have been variations in details of design but the essentials are similar in all. I wish to describe the operation of a typical drag-line dredging plant, that of the Wyandotte Gold Dredging Company on the Farnan Ranch in the Oroville district. This organization of six active partners built their first plant on Wyandotte creek in the autumn of 1933. The operation was successful due to wise management, which was based upon good plant design and proper principles of operation. The partners elected one of their number, H. F. England, as manager with full control and responsibility. This plant and operation furnished the pattern for many subsequent ones.

Jan 1, 1937

By N. W. Xu, C. Sha, F. Dai, Y. G. Zhu, B. Li

Underground caverns stability and excavatability of rock masses are of significance in geotechnical engineering, in both design and construction stages. Risks associated with underground group caverns of Houziyan hydropower station in southwestern China are growing as a result of continuous excavation-induced unloading. To improve our understanding of the underground caverns instability and resolve the complex subsurface conditions of the highly fractured rock mass, a high resolution microseismic monitoring system was established in the deep underground caverns, pursuing the relationship between the measured data about microseismic activity and excavation damage zones of surrounding rock mass. Through analyzing the tempo-spatial distribution of microseismic activity, excavation damage zones and potential risk regions in underground caverns were identified. Furthermore, the correlation between microseismic activity and pre-existing geological structures, as well as traditional monitoring was analyzed. In order to validate the correlation between seismicity and potential slip surface of underground caverns, a model was implemented into numerical code to further evaluate the deformation and stability of surrounding rock mass. The monitoring results demonstrate that microseismic events mainly occur at high stress concentration regions, which coincides with the results obtained from numerical analysis. Therefore, the comprehensive method incorporating microseismic monitoring and numerical analysis, as well as traditional monitoring and filed observation has been proven to be very promising in deformation and even instability prediction of surrounding rock mass in underground caverns subject to delineation of potential slip surfaces and excavation damage zones.

Jan 1, 2015

By Makhlouf Boubahziz

The HNIA field is part of the Tinrhert project which consists of developing 17 fields containing essentially gas with a few small rings of oil. It is considered as one of the main fields in this project in terms of its area and the number of geological structures that has formed it. It is a wide anticline of Cambro-Ordovician age, orientated NNE-SSW and located in the South-eastern part of Illizi basin. This structure extends from Alrar-center in the North, to the North of In Amenas in the South. The area is 1350 km2. The main reservoirs forming HNIA field are the Devonian (F2, F3 and F4), Siluro-Devonian (F6) and Cambro-Ordovician. These latest are formed by 4 sandy units alternated by layers of shale and shaly silt termed from the base to the top as follow: Unit II, Unit III-3U, Unit IV-2L and Unit IV3; these units are the subject of this study. The HNIA field is essentially gas, up to day this field is at the stage of appraisal and evaluation in order to establish a development plan; therefore the main target of this study is to contribute to this frame work. The following objectives are: ?To build a structural model of the study area. ?To integrate all the sedimentological, structural and petrophysical data in order to build a 3D geological model

Aug 1, 2013

By J. Shanks

In 1920 the writer presented some notes, embodying his experience with storage-battery locomotives as main under-ground haulage-motors at Brazeau collieries. (1) Since that date these motors have stood up well to the test of maximum output and heavy overloads, having accomplished all that was expected of them. The notes presented in 1920 gave a brief description of the conditions under which these motors were working at Brazeau collieries, also the cost, per ton mile, of operating them. The cost per ton mile has since then been appreciably reduced, by working the locomotives nearly to capacity and under more ideal haulage conditions, on both shifts. It is not the intention of the writer to repeat what was written in 1920, but rather to give members the benefit of his experience in operating different types or designs of locomotives; to draw their attention to the drawbacks of some designs, and to the improvements made in some of the more recent storage-battery locomotives put on the market, as regards efficiency, upkeep, and safety. Because of their flexibility storage-battery locomotives have advantages over any other type of haulage, where grades are suitable to their use. The number in use in the mines in the United States has increased enormously during the past few years, and this method of haulage is, at the present time, attracting the attention of British and Continental mining engineers.

Jan 1, 1924

By C. A. Biley

"A dedicated iron removal stage was installed at Anglo American Platinum’s Rustenburg Base Metals Refiners (RBMR) during an expansion project which began execution in 2010. The Pressure Iron Removal (PIR) process aims to precipitate iron from a nickel leach solution under medium temperature (145 °C) oxidative conditions using caustic for neutralisation. Since commissioning, the process has been robust in removing iron from the refinery but has shown significant variability in the residues produced. These residues, which are typically comprised of ferrihydrite, hematite or natrojarosite, have varying iron contents and different physical properties which have implications for their filtration and ultimate removal from the refinery. Since over 95% of nickel plated at RBMR passes through the PIR section, volumetric constraints caused by poor filtration performance directly influence nickel production and stabilisation of this process remains central to the continued ramp-up of the refinery to full nameplate capacity. This paper details the development of the PIR process and the journey from concept to implementation. Recent laboratory and plant scale tests have highlighted the importance of the initial phase formed in the autoclave for the ultimate residue requiring filtration and how the feed acid concentration is a critical control parameter. On this basis, a new caustic dosing philosophy was implemented which improved pH control in the autoclave. Further optimisation of the PIR process is on-going.INTRODUCTIONIn 2010, an expansion of Rustenburg Base Metal Refiners (RBMR) to increase nickel production from 21 to 33 ktpa began execution. The management of iron was pivotal in the ultimate configuration in the new circuit and one of the primary differences from the original circuit was the addition of a dedicated iron removal stage: Pressure Iron Removal (PIR). A significant drive for this new unit operation was to facilitate the separation of iron from other leach residues. Not only did this result in a significant decrease in the amount of leach residue but, without the constraints associated with iron precipitation during leaching, has permitted more aggressive leaching conditions and, correspondingly, greater throughput and efficiencies.However, as with many commercial implementations of even mature technologies, the journey from development to implementation has presented challenges for the continued ramp-up of the refinery to full nameplate capacity. Specifically, since all nickel bearing leach solution must pass through the PIR section prior to the nickel purification and recovery circuit, throughput difficulties in the PIR section can directly impact supply of feed to the nickel tank house. Since commissioning, the PIR autoclave has effectively removed iron from the refinery, but has shown significant variation in the solids phases produced in the autoclave. This variation presents difficulties for the filtration of the discharge slurry and represents a key throughput limitation which periodically impacts production. Additionally, the increasing production rates associated with the ramp-up of the refinery have resulted in a significant increase in the required volumetric throughput through the PIR process. This has placed even greater emphasis on improving the stability of the solid phase produced in the autoclave, ultimately targeting an easily filterable residue with high iron content."

Jan 1, 2016

By Stuart McTavish

"The Brunswick Mining concentrator processes 10,000 D.S. T. per day of a complex sulphide ore. Four separate concentrates- zinc, lead, copper and bulk-are produced by selective flotation. Several major changes have been made to the Brunswick flotation circuit to improve the process and control. This paper will describe the present flotation practices at the Brunswick Concentrator. Special emphasis is given to the conversion of two of the primary circuits to an SO2-aeration flowsheet, and to the addition of a new secondary zinc flotation circuit that produces a zinc concentrate from the plant tailings. IntroductionBrunswick Mining and Smelting Corporation operates a zinclead- copper and silver mine and concentrator near Bathurst, New Brunswick. Since the start-up of operations in 1964, the flotation flowsheet has undergone major modifications to process the increased tonnages and to produce a greater number of concentrates. The flowsheet for the concentrator as it was in 1971 has been described by Neumann and Schnarru) and by Ersklneco. Since then, in 1971, the No.6 concentrator was converted from bulk flotation to selective flotation to produce a copper, lead and zinc concentrate. A separate zinc upgrading circuit was installed in 1972 and a bulk flotation or dezincing circuit, which reduced the zinc in the lead concentrate, was started in 1973. In 1976, the secondary zinc circuit was initiated.In addition to these new circuits, changes have been made to the existing circuits to simplify their operation."

Jan 1, 1980

By Patrick R. Stephenson

The Australasian Code for Reporting of Mineral Resources and Ore Reserves (the ?JORC Code?) has been operating successfully for 14 years, and has an ancestry dating back over 30 years. Together with complementary developments in stock exchange listing rules, the Code has brought about substantially improved standards of public reporting by Australasian mining and exploration companies. The Code is regarded as a world leader in its field, and has been used as a basis for the development of resource/reserve reporting standards in other countries. The reasons for its success are varied, foremost amongst them being its adoption in full by the Australian and New Zealand Stock Exchanges, and the ability and willingness of mining industry organisations to bring Competent Persons to account when necessary. The latest revision of the JORC Code was undertaken in 2002/03, based in part on releases of upgraded reporting standards in Canada, United Kingdom/Western Europe and South Africa, and the 2003 edition is expected to be released mid-year. Two of the more significant changes are: the introduction of a requirement for a Competent Person to be responsible for the documentation upon which Exploration Results are reported; and inclusion in the definition of a Competent Person of a reference to ?Recognised Overseas Professional Organisations?, being overseas professional organisations to which Competent Persons may belong for the purpose of preparing documentation for the submission of reports to the Australian Stock Exchange.

May 1, 2003

By K. John

"THE most recent estimate of minteable coal reserves in Saskatchewan was made by the Federal Royal Commission on Coal (1944- 6). Saskatchewan was then estimated to have some 24 per cent of the Canadian reserves and two-thirds of this is located in what is called the Souris-Estevan area, which lies in the southeast corner of the Province and border's on the International boundary. It is also estimated that there are some 61/2 million thousand-tons in this area of lignite coal which grades 8,000 B.t.u. or less and has a moisture content ranging from 30 to 33 per cent. Ownership of coal rights in the Province is widely dispersed between the Crown, individuals, and corporations, and a recent survey disclosed that 40 percent of ownership was vested in the Crown and 60 per cent in private individuals and corporations. Coal rights on Crown lands may be leased at an annual rental of $ 1.00 an acre. Under such leases, a royalty of 5 cents a ton is levied on all coal mined. A royalty of 7 cents a ton is levied on coal produced from lands where mineral rights were purchased from the Federal Government prior to the transfer of jurisdiction over natural resources to the Province, in 1931. An annual mineral tax of 50 cents per acre has also been imposed by the Provincial Government on all coals within a defined producing areas."

Jan 1, 1952

By D. Brossman

"The virtue of spray drying is that it is a drying method, and so far the only one by which it is possible in one operation to divide a mineral concentrate into its basic primary particles.,In so doing, each particle gets the same treatment and the result is a dry concentrate more homogeneous than any other known concentrate drying process. This is particularly good for a flash furnace requiring a bone dry finely divided feed. The spray dryer also features a very short residence time and due to the very quick operation the solids are kept cool thus preventing any risk of fire or explosions on these pyrophoric materials.There are many spray dryers now in operation in the mining industry and one of the latest applications is in South Africa where a spray dryer is treating a copper-nickel platinum concentrate which is, after drying, fed toan electric arc furnace. Experience has shown that the concentrate should contain 4% moisture for the furnace, and this is achieved by drying the concentrate bone dry and then back-mixing with thickener underflow pulp to provide an extremely homogeneous feed to the smelter. As mentioned before, mixing with pulp would be more of an advantage because we would not be evaporating water which would have to be added again afterwards.One of the first spray dryers to go in was at Western Mining Corporation in Kambalda in Western Australia. (A series of slides was then shown)."

Jan 1, 1972

By H. E. Frimmel

Most of the gold in the Late Archean Witwatersrand Basin is of detrital origin but, in its present form, it is metamorphosed. The only relict detrital features preserved are the morphological characteristics of some placer gold particles. Regional burial metamorphism in the shallower and deeper levels of the Witwatersrand Supergroup reached temperatures around 300°C and 350°C at pressures between 2 kbar and 3 kbar, respectively, estimated from phase relations, chlorite-chloritoid exchange thermometry and chlorite thermometry. Metamorphism of the gold involved compositional homogenization of individual gold particles and partial recrystallization. Various infJ.1tration events caused the partial mobilization of the gold at slightly lower temperatures, between 240°C and 300°C. These infiltrations can be related to crustal extension during the deposition of massive carbonate sequences of the Transvaal Supergroup (around 2.5 Ga), and later to the emplacement of the Bushveld Complex, and to the Vredefort event around 2.0 Ga ago. The mobility of the gold was dependent on the sulfur fugacity prevailing in a particular horizon which, in tum, was determined by the amount of pyrite (and other sulfides) present in that horizon. With the sulfur fugacity being controlled by stratigraphy, low fluid rock ratios in a pyrite-rich horizon were most conducive for the mobilization of the gold. Thus, long-range gold mobilization in the Witwatersrand Basin can be expected to be the exception rather than the rule.

Jan 1, 1994

By J. H. Rickard, D. H. Watkinson

"Abstract - Detailed petrographic and quantitative (electron microprobe, SEM-EDS) mineralchemical analyses of sulfide ore from the 100 orebody at the Copper Cliff North mine, Copper Cliff, Ontario, reveal numerous stages of ore development. Sharp contacts between weakly mineralized quartz diorite and blebby to massive sulfides indicate multiple intrusive events within the Copper Cliff offset dike. A spatial association of sulfides and hydrous minerals, such as amphibole, biotite, chlorite and epidote, suggests that most primary ore has been affected by later hydrothermal fluids. Sulfides are often enclosed or bordered by these secondary silicate phases. The ore consists primarily of pyrrhotite, pentlandite, chalcopyrite, with trace michenerite, cobaltite/gersdorffite, irarsite, hessite, tsumoite, and bismuth tellurides.Geological and petrological comparison of the 100 orebody and the adjacent 900 and 890 orebodies has revealed distinct similarities in ore distribution. Data show that the 100 orebody is depleted in platinum-group elements (PGE) relative to the 900 orebody. Platinum-group elements from the 100 orebody may have been hydrothermally remobilized and partly emplaced in the 900 orebody, in adjacent veins, or in magmatic breccia. Analysis of Cu, Ni, and PGE assay data of ore samples has characterized their distribution among the eight different ore textures in the orebody. There is a strong association between Pt and interstitial sulfide, and to a lesser extent massive sulfide, but little correlation between chalcopyrite-rich ore and PGE in the 100 orebody, unlike many other deposits in the Sudbury region."

Jan 1, 2001

By W. A. Jones

"The Hollinger gold mine is in the Porcupine area, Cochrane district, in northern Ontario. The adjacent town of Timmins, which has a population of 25,856, lies 490 miles by railway north of the city of Toronto.The property was staked in the late summer of 1909. The original four claims were staked by Benjamin Hollinger, after whom the mine was named. Development commenced in the autumn of 1909 and mill construction in the winter of 1910. A catastrophic forest fire swept the district in 19ll, destroying the surface plant, so that the original 300-ton mill was not completed until June 1912. From that date up to December 31, 1945, 44,280,750 tons of ore have yielded 13,636,796 oz. gold and 2,613,354 oz. silver. The total value of the production has been $363,638,315.0REBODIES AND MINERALIZATIONThe orebodies consist of quartz veins, stringer lodes, and scockworks, with associated pyritized wall-rocks. The width of individual orebodies, as exposed by mining operations, ranges from 1 to 70 feet and averaged approximately 10 feet in 1942. The vein system forms a complex pattern in a favourable zone, which in places is 6,000 feet long and 4,000 feet wide. The deepest level being developed is 5,150 feet below the surface. Few veins are persistent for long distances, although some are continuous for more than 1,000 feet longitudinally and vertically.The host rocks consist of a closely folded series of Precambrian lava flows of Keewatin age. These are schistose and hydrothermally altered, but are believed to have originally been of intermediate to basic composition. The schistosity strikes N.70°E. and dips to the south at 75° to 80°. The structure of the formations is complex, but in the principal ore-bearing zone the general dip of the flows is to the south at a slightly flatter attitude than the schistosity."

Jan 1, 1954

By G. S. Hume

Introduction O WING to the mineral discoveries which have recently been made in the Great Bear Lake region and the possibility of the need for fuel for transportation and development, it seems.timely ro review available information regarding the oil prospects in the vicinity of Great Slave lake and Mackenzie river, where a vast area is underlain by Palreozoic and younger sediments that undoubtedly are petroliferous. Exploratory surveys were carried out in this area by the Geological Survey and others in the latter part of the 19th century, but it was not until 1920, when drilling for oil actually began, that any serious attention was paid to the oil prospects. This is readily accounted for by the remoteness of the region, the lack of quick transportation facilities, and the shore summer season. Numerous and copious oil seepages had been reported, however, from widely separated localities, and interest was stimulated by the knowledge that these occurred in Devonian strata which had given a remarkable record of sustained production of high-grade oil in the oil-fields of southwestern Ontario. . Accordingly, during the four years 1920 to 1923, inclusive, several parties sent out by the Geological Survey made as thorough an investigation of various parts of the area as seemed warranted at that time, and from these surveys most of our information regarding the details of the stratigraphy is derived. In such a large area, it is inevitable that the lithology and thickness of rocks of the same age would show wide variations, and hence it should be recognized that conditions as regards oil prospects in the vicinity of the west end of Great Slave lake are quite distinct from those that occur near Fort Norman, 400 miles farther to the northwest, and these again are in all probability quite different from those in the less well known Arctic Red River area, 250 to 300 miles still farther north.

Jan 1, 1932