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By W. van der Merwe

With the gold industry looking to process more complex ores, the online measurement and control of cyanide addition to the gold leaching circuit has become more crucial. This paper compares the two commonly employed "free" cyanide online analysis methods (amperometric and potentiometric end-point silver nitrate titration) with the common site laboratory rhodanine endpoint silver nitrate titration and ion selective electrode methods. Measurement differences between these methods are presented and discussed for cyanide solutions containing copper and zinc with varying cyanide to metal ion ratios. The resulting cyanide available to leach gold is also compared with these measurements.

Jan 1, 2011

By B. A. McKee, T. Adamcewicz

For a capital expenditure of only $46,000, Caland Ore Company has successfully converted its three dry grinding center peripheral discharge rod mills to dry grinding ball mills. The conversion has resulted in a significant capacity increase, operating cost reductions and in-plant environmental improvements. This paper describes why and how• the conversion was made.

Jan 1, 1972

By R. P. Viljoen, A. L. Sokolov

"The distribution of mineralized provinces is analyzed on the basis of their genetic link with specific blocks of the earth's crust including ancient platforms, mobile belts and zones of tectonicmagmatic activation. Mobile and fold belts surround the Siberian platform in Russia and the Kaapvaal craton in South Africa, with decreasing age zoning away from ancient platform margins. The main differences in the geological development of the two cratonic areas are: (1) the long period before the final stabilization of the Siberian platform (3600 Ma to 1600 Ma) and the comparatively short period of time for the stabilization of the Kaapvaal craton (3600 Ma to 3050 Ma) and (2) the intensive multiple activation of the marginal zones of the Siberian platform and the tectonicallycontrolled, magmatic sedimentary, intracratonic activity, typical of the Kaapvaal craton. Mineralization of the Siberian platform is largely characterized by marginal reactivation zones of differing ages although mineralized intracratonic Cu-bearing basins of Proterozoic age are also known. Mineralization of the Kaapvaal craton is mainly related to the formation of the intracratonic basins i.e., Witwatersrand (Au, U) and Transvaal (Au). The latter is characterized by multi-age volcanic-intrusive activity including the emplacement of Bushveld Complex (Cu, Ni, Pt, Cr, Au, V). The Siberian platform is characterized by the prolonged development of inherited mineralization from Archean until the late Mesozoic. The main period of mineralization in the Kaapvaal craton is restricted to the middle Proterozoic.The Baykal-Patomskaya and Namaqua-Natal mobile zones occupy similar positions adjacent to the Siberian and Kaapvaal cratons, respectively, and demonstrate similar modes of metallogenic development: i.e., the early formation of exhalative Pb-Zn-Cu deposits during the early stage and magmatic Cu deposits during the late stage. The more remote mobile belt near the Siberian platform, the Trans-Baykal, is characterized by intensive multi-age mineralization (Wo, Mo, Sn, fluorite), related to a period of tectonic-magmatic activation. The Saldania Belt occupies a similar position near the Kaapvaal craton but is known for its poor Au, and Cu mineralization. It does, however, have some similarities with Trans-Baykal Belt in regard to Mo-W bearing granitoids.The phenomenon of interference of geosynclinal, orogenic, platform, and tectono-magmatic activation regimes is known for the Russian section of the Pacific Ocean Volcanic Belt."

Jan 1, 1994

The most expensive unit operation in the beneficiation of ores is grinding. The correct design of the grinding circuit is crucial to prevent unnecessary use of energy. Proper design and evaluation of SAG grinding circuits require the specific grinding energy, which is determined experimentally. The most common tests in SAG grinding are the Drop Weight Test, from the Julius Kruttschnitt Mineral Research Center (JKMRC) in Australia, and the SAG Power Index, from MinnovEX Technologies in Canada. The application of these tests to the same ore sample commonly produces different results. The work reported here aims at comparing the application of these two tests in the determination of the specific grinding energy for sulfide copper ores from Sequeirinho and Sossego deposits, Sossego Project, Companhia Vale do Rio Doce - CVRD, in Para state, Brazil.

Jan 1, 2007

By M. Hajian Heidary

In this investigation, effect of pressure depth on the globulizations of AZ91 magnesium alloy was studied. Cylindrical samples of AZ91 alloy with 1 cm and 2cm in height and 2.5cm in diameter (H/D = 0.4 and 0.8) were prepared, then the samples were hot pressed at 10 and 30% strain at a constant temperature of 200°C; subsequently reheated at 555°C in different times. Results obtained from optical microscopy (OM) showed that the thickness of the samples and consequently, depth of strain affected regions have remarkable effect on the degree of globulization. In addition, it was found that at a constant strain and holding time, structure of thinner samples is more globular than thicker ones.

Jan 1, 2007

By K. Shikaze

"For the last three years (1967-9) the value of the output of mineral resources in the Province of Ontario exceeded one billion dollars per year. To produce this great wealth, it was necessary for the mining industry in Ontario to dispose of an estimated 80 million tons of waste mill tailings. Some of these tailings were returned underground but the greater proportion was disposed of above ground in lakes, watercourses, marshy areas and in engineered impoundment basins. This volume of tailings, if accumulated in one location would cover an area of 1000 acres to a height of almost thirty feet. The provision of proper disposal of the waste mill tailings in a manner such that they will not create problems in the environment is one of the costs which must be borne from the extraction of such a wealth from our mineral resources. It is principally the potential water pollution which may occur as a result of the indiscriminate discharges of waste mill tailings which is of concern to the Ontario Water Resources Commission.ONTARIO WATER RESOURCES COMMISSIONThe Ontario Water Resources Commission was formed in 1956 and operates under the Ontario Water Resources Commission Act. The Act has been broadened and amended many times by amendments."

Jan 1, 1970

By K. Fagerlund, L. Rosenback, T. Mäkinen, Y. Anjala

This paper deals with the nickel smelter and refinery concepts Outokumpu has applied at Harjavalta and several other plants. Also other process routes and modifications developed and tested by Outokumpu during the recent years are highlighted. Outokumpu started nickel production in Harjavalta in 1959. Until 1995 the Flash Smelting - Peirce-Smith (PS) converting route was applied. High grade nickel matte from the converting step was further refined by means of leaching and electrowinning to produce cathode nickel. In 1995 the nickel production capacity was increased from 17 000 t/a to 52 000 t/a based on the Direct Outokumpu Nickel Smelting Process (DON). In the DON process PS converting is eliminated and high grade nickel matte with low Fe-content is directly produced in the flash smelting furnace (FSF). Metal values from the smelting slag are recovered in the electric furnace (EF) as iron containing Ni-matte. The DON process can be operated with either two matte concept, where high grade FSF matte and EF matte are produced, or a single matte concept, where EF matte is recycled to the smelting furnace and thus only one type of high grade matte is obtained. The additional refinery capacity at Harjavalta is based on hydrogen reduction producing.

Jan 1, 2005

By R. Loj

Katowice Coal Holding (KHW) is one of the largest coal companies in Europe. The company owns five coal mines with a daily output of around 60 000 tons of coal. In the Katowice city area, very good quality steam coal is extracted. The depth of mining varies between 400 and 1100 m and some of the mines rank amongst those most afflicted by methane in the Upper Silesian Coal Basin, with the methane hazard having a significant impact on production and safety. ?Myslowice-Wesola? mine, being a part of the Katowice Coal Holding is characterized by high methane and rockburst hazards. The mine is equipped with a modern surface drainage pumping station. At the mentioned mine, longwall 514 was selected for analysis of its methane emission. The longwall was extracting the thick seam 501 (over 4 m), at a depth of over 900 m, which was subject to high stress and high gas concentration conditions. At a distance of about 50 m above, seam 501 is covered by thin seam 416. The strata between these two seams are sandstone and mudstone layers. In the floor of seam 501, with a thin shale interlayer, is located seam 510, which is the thickest (over 10m) and richest coal seam in the Upper Silesian Coal Basin. In longwall 514 and it?s vicinity, methane was the dominant risk. For this longwall three methods of classical gas drainage were carried out. At first, drainage was undertaken using long boreholes from a cross-cut at level 665 m, located far from the production panel. Later, it was performed using typical boreholes drilled from the ventilation gallery (tail gate road). Finally, it was undertaken using a degassing drift executed in the upper coal seam 416. All of these headings, ie. cross-cut level 665 m, the ventilation road and conveyor road in seam 501 and the degassing drift in seam 416, were equipped with media for drilling and proper drainage pipelines. Due to the high rockburst hazard and some problems with caving, several kinds of de-stressing and torpedo blasts were carried out in both coal seams and roof rocks. The subsequent analysis and experiments allowed the establishment of some general rules for carrying out degassing operations effectively. The effectiveness of a degassing drift was demonstrated. In some instances, the system allowed more than 70% of the total methane released to be captured and fed into pipelines. The aforementioned blasts had a marginal impact on methane emissions and the efficiency of degassing methods. Cyclic drilling and regular switching of boreholes in phase with the mining progress and working face advance were shown to be essential.

Aug 1, 2013

By A. W. Jacob

THE shatter cut, or burn cut as it is often called, is one in which the centre of the round is almost reamed out by drilling holes so close together that the blasting of a few holes shatters the rock embraced by all of them. The idea of shattering the centre of a face by shooting holes drilled parallel to one another is not new. Some miners have used this method for years past, when drilling quartz or a face near timber. But, they followed the age-old practice of first blasting the cut, then the square-up. It was not thought possible to shoot both together. In the case of machine men, the two largest contributors to silicosis are dust from drilling and dust from blasting. It follows, then, that material reduction of exposure to either constitutes an important step in lessening the incidence o silicosis. It was? the hope of being able to do away with the necessity of the men having to return early to a face, through dust concentrations of 60,000 to 80,000 particles per cubic centimeter, that aroused interest "in the shatter cut at McIntyre. Efforts to this end were successful. Now, with this kind of cut, all holes of a round are shot simultaneously.

Jan 1, 1942

By H. R. Taylor

The history and development of this property is more or less familiar to nearly everyone connected with the mining industry, so that only a brief outline of the more important facts will be given in this article. In 1916, a small pilot mill was constructed by the British Columbia Copper Company at Copper Mountain, and during 1916 and 1917 test work was conducted to determine the possibility of concentrating the ore and also to work out a suitable flow-sheet. In the spring of 1917, the location of a mill site at Allen by, which is about 8,% miles from Copper Mountain, and near the Similkameen river, was decided on, and the designing of a 2,000-ton plant was then worked out by Bradley, Bruff and Labarthe. Early in 1918, the actual construction of the concentrator began, and, after considerable labour difficulties, it was completed in 1920. During this period of construction, the West Kootenay Power Company ran a 60,000-volt power line over from Greenwood, a distance of 102 miles, and also built a sub-station at Allenby to take care of the mine and mill. The concentrator was started up on October 20th, 1920, and ran until December 11th, 1920, a total of 18,354 tons of ore being milled. The results of this short period of operation were encouraging, but, due to tlie prevailing low price of copper and high wages, it was necessary to shut down until a more favourable time. During the latter half of 1923, some work was done on remodelling the mill. This work continued until January 8th, 1924, when it was suspended.

Jan 1, 1929

By A. V. Lyamin, J. P. Wang, A. J. Li, Z. Qian

"For general stability analysis of rock slopes, rock mass strength and rock mass disturbance are definitely should be considered. In addition, the impact of earthquakes must be taken into account. In fact, the rock mass strength is very difficult to be assessed which causes the difficulty of analysing rock slope stability. Therefore, an empirical failure criterion, the Hoek-Brown failure criterion, has been proposed. It is one of the most widely accepted approaches to estimate rock mass strength. The rock mass disturbance is important and was found having significant influence on evaluating rock slope stability, especially for rock slope with poor quality rock mass. In the Hoek-Brown failure criterion, the disturbance factor can represent the level of the rock mass disturbance which would provide a reasonable basis for estimating rock mass strength.This research will not only discuss the slope factor of safety, but also consider the influence of the seismic force on rock slope stability assessment using pseudo-static method. In practice, only horizontal seismic coefficient is used. Various magnitudes of the disturbance factor and recommended blasting damage zone thickness are also taken into account. The blasting damage zone thickness considered ranges from 0.5 to 2.5 times of slope height. The research results have potential to be extended and then sets of comprehensive stability charts can be provided for the rock slope stability evaluations. They will be convenient tools for practising engineers. In this study, finite element upper bound and lower bound limit analysis methods are employed. Their applicability has been investigated in some previous studies. The differences between upper bound and lower bound solutions are less than ±10% which would provide reasonable and acceptable range for rock slope stability safety factor estimation."

Jan 1, 2015

By R. D. Brown

In the spring of 1977, Revenue Canada announced its intention to proceed in 1978 with a plan to impute a taxable benefit on interest-free and low-interest loans provided to employees. Such loan arrangements are often an important aspect of the compensation packages provided by many companies to their employees. Since the original announcement, there have been many submissions to Revenue Canada opposing this change, and the Finance Minister has now brought down a compromise solution with the introduction of a proposed amendment to the Income Tax Act. The amendment, which would not take effect until the 1979 taxation year, would require an employee, a shareholder or a related person to include a benefit in income measured as the difference between the interest on any such loan computed at bank prime rate and any interest actually paid. Only the amount of such a benefit in excess of $500 in a particular year would be required to be included in income. Of particular interest is the exclusion from these benefit rules of loans up to $50,000 in respect of the purchase of a house on the relocation of an employee and loans provided for the purchase of shares of an employer corporation.

Jan 1, 1978

By Ronald E. Pike

"PREFACEAt the CIM Annual General Meeting in Quebec City, R.E. Pike of The Toronto-Dominion Bank described how the Canadian banking industry worked with the minerals industry to assemble the large capital requirements for resource projects in Canada and overseas. He developed a profile of the mining industry and Canadian banking, both being important sectors of the Canadian economy and global in context. He also outlined the banking and financing partnership that existed in the past. In looking to the future and challenge that lies ahead f or each industry, Mr. Pike questioned whether the financing practices of the 1970s will be acceptable over the next decade. In that regard, he highlighted the risks that impact on each industry and illustrated how that financing partnership might evolve in response to those forces. The folio wing is a synopsis of his paper.IntroductionThe Canadian mining and metals industry is prominent in the domestic economy and respected internationally. Any measure of its performance illustrates that status-percentage of GNP, employment, exports, capital investment, size relative to other producing nations, etc.Energy, Mines and Resources Canada has forecast that the non-fuel minerals industry will grow in real terms by an average annual rate of 3.0% over the period 1981 to 1991. Using the GNP as reference, that growth in non-fuel mineral production will represent 7.7% of GNP. In translating that growth to capital expenditure, the EMR Canada estimates the aggregate amount at $43.8 billion ('79 dollars) or approximately 12% of total business investment in Canada during the 10-year period.About half of the $43.8 billion will be devoted to the ferrous sector-$8.4 billion in iron ore mining and $12.4 billion in the steel industry. Capital investment in nonferrous s projects is estimated at $13.3 billion, and it is projected at $6.7 billion for industrial minerals. The residual $3.0 .billion is exploration spending."

Jan 1, 1982

By Kazuteru Tozawa, Robert G. Robins

"The stability of calcium arsenate is discussed in relation to the possible misuse of lime in the treatment of gold processing waste waters. Stability diagrams have been derived and experimental results cited to show that calcium arsenate has a higher solubility in neutral to alkaline solution than has previously been recognized and this solubility is further enhanced by the presence of carbon dioxide, bicarbonate or carbonate.IntroductionThe removal of arsenic from gold mine waste waters has been of interest for more than thirty years, but with the recent emphasis on clean water standards there has been renewed activity in relation to that problem. The processing of gold-bearing sulphides which contain arsenopyrite and other complex arsenic sulphides is well established. Initial roasting to oxidize the sulphides leaves the arsenic in the form of both arsenic and arsenic, in which forms it is soluble in the subsequent leaching stage. Further oxidation of the leach liquors is required before the well-established procedure of precipitating calcium arsenate with lime, which is carried out despite an immense lack of knowledge of the calcium-arsenic-water system.The solubility product and free energy of formation for Ca3(AsO4)2, which are to be found in recent and reliable sources of data, originate from the work of Chukhlansev, whose experimental determination of the concentration of calcium from the solubility of calcium arsenate in solutions of various pH yields the results plotted in Figure 1. This is the work which has resulted in a wide acceptance of the ""insolubility"" of calcium arsenate and the use of lime to stabilize arsenic in that form.Laguitton attempted to further elucidate the chemistry of the lime addition method for treating arsenical waste waters from gold processing operations. The low solubility product for Ca3(AsO4)2 was the basis for his examination of likely chemical equilibria in the system. Laguitton and other workers have not considered atmospheric carbon dioxide as an important component in this system."

Jan 1, 1982

By Dennis Z. F. Mraz

"Because rock salt and pot ash formations contain particles capable of elastic deformation, the material has usually been compared with various rheological models containing elastic elements. Extensive laboratory testing of salt and potash samples resulted in various theoretical conclusions based on conditions quite different from those in a deep mine. It is felt that sufficient data have now been collected from underground measurements and observations to demonstrate the inelastic behaviour of salt masses in a deep mine. The conditions in deep salt strata can be defined as near hydrostatic, because the acting pressures are very high compared to the negligible elastic limit of the salt. The pressure field and creep around the single opening is a function of its shape, size and age. The same factors, together with extraction, determine the behaviour of the mining a rea. The application of the correct analytical method in mine design can significantly improve the excavation techniques and predetermine the long-term behaviour of openings."

Jan 1, 1973

By J. Jacob, A. G. Guézennec, F. Savreux, S. Nanaa, M. Delclaud, P. d’Hugues

Mining wastes can contain base and precious metals, but also metalloids and rare earth elements that are nowadays considered as highly critical for the industrial development of the European Union. The development of alternative routes to conventional processing is still required in order to decrease the cost associated with the treatment of these resources, which are more complex in composition and with lower grades. An ecologically acceptable and yet economic alternative for processing of low-grade sulphidic primary ores as well as mining wastes is the extraction of metals using bioleaching processes. The purpose of this study was to test the potential of bioleaching procedures for the extraction of residual metals contained in sulphide-rich tailing wastes coming from a European copper mine. These wastes are mainly composed of pyrite (60%) and contain cobalt (0.06 %) and gold (0.95 g/t). Bioleaching experiments were performed in 2 L stirred reactors in batch mode and in pilot tanks (110L) in continuous mode, using the "BRGM-KCC" bacterial consortia. High metal extractions were obtained (cobalt dissolution > 90%), which confirm that bioleaching is an effective process for this tailings material. Experimental results were used to design a global treatment process scheme and to perform a preliminary economic evaluation, showing good profitability of a hypothetical industrial project.

Jan 1, 2014

By A. Manohar Rao

Underground mining in general and more so the coal mining is a hazardous venture as it is a struggle against nature and natural forces. The stability of roadways has a direct impact on production and productivity. The roadway stability can be strongly influenced by the direction of the drivage. The stress studies are useful to provide a frame work for understanding the influence of drivage direction on roadway conditions, and to illustrate how mapping techniques can enhance this understanding. The act of mining can concentrate and re-orient the original stresses. Whenever coal is removed, the overburden weight that it carried is transferred. Vertical stresses are similarly affected when the roof is deformed or failed. The Singareni Collieries Company Ltd., a joint Public sector undertaking of the Government of Andhra Pradesh and India is conducting coalmining operations in the Godavari Valley Coalfield and is catering to the needs of a large part of South India. With the technology update, it is looking for safe mining and to achieve higher production. As a part of this, an attempt is made to understand the stress conditions prevailing on the mine blocks by different ways and means in terms of geology, structure and tectonics of the Godavari Valley coalfield, satellite imagery studies, cleat pattern, stress measurement studies conducted in different mine blocks, and stress mapping technique.

Aug 1, 2013

By G. R. MANSON

The Brisco Barite Mine lies 70 km south-southeast of Golden, British Columbia. Barile mineralization occurs in a northstriking brecciation zone within Ordovician-Silurian Beaver/ oot dolomites and quartzites. Brecciation was caused by faulting related to the Mount Forster-Steamboat Fault. The main barite vein occupies a fault zone and is up to 12 m wide and over 250 m long. It is light grey to white, fine grained and compact; BaSO4 content is 9/. 70 per cent. Production started in 1945 and has continued to the present. Barile originally was removed from an open pit; later, an adit, begun in 1957, reached more than 240 m along the vein, 15 m below the pit floor. Today ore is hoisted from a decline resting some 37 m below the pit floor.

Jan 1, 1984

By P. A. Bahri, D. G. Dixon, T. M. Woodward

A comprehensive mathematical model of the Sherritt-Gordon ammoniacal pressure leaching process at K winana Nickel Refinery has been constructed. The process is comprised of six autoclaves functioning as a three-stage leach circuit, operating over the temperature and pressure ranges of 85-95°C and 750-1000 kPa, respectively. The process chemistry forms a complex series-parallel reaction network, characterised by: (1) the gas-liquid mass transfer and reduction of oxygen, (2) the oxidation of eight distinct minerals, (3) the oxidation of sulphur, and successive reactions involving various intermediately oxidised sulphur species, and (4) the oxidation of Fe(II) to Fe(III), and subsequent precipitation as a hydrated ferric oxide. Material balances were developed for species in all three phases, and an energy balance to account for all reactions and phase conversions. The multiple convolution integral (MCI) statistical reactor model was employed for the scale-up of particle kinetics. The model has been validated against plant data, and simulation results are in agreement with plant performance.

Jan 1, 2005

By W. G. Worcester

IN the presentation of this paper to the Institute, three objects are in the mind of the writer: first, to set forth the close relation which, of necessity, exists between ceramics and the industrial minerals; second, to clarify the apparently hazy understanding which many have of ceramics in general; and lastly, of equal or even more importance, to stimulate a greater interest in the industrial minerals, especially in those used and required by the ceramic industries. While Canada is now producing in large quantities a fairly wide variety of the ceramic industrial minerals, there are some which are not known to occur in the Dominion. Hence it is to be desired that our geologists, prospectors, and others, while on field work, should be on the look out for commercial deposits of such minerals as diaspore, bauxite, ucts of a value in excess of $600,000,000, a figure which places ceramics as kyanite, massive topaz, and sillimanite. A find of any of these in quantity would prove of very great importance and value to the country as a whole. At this point it seems desirable to introduce formally the word ceramic or the plural of it, ceramics. In doing so it may be stated that the origin of the word dates far back in history in that it was derived in part from the Greek word Keramos, 'a potter' or 'pottery', which in turn has been traced back to an older Sanskrit root meaning 'to burn' or 'burned stuff', having reference, no doubt, to burned pottery or other clay wares; and the word was so used until near the close of the last century, when the world's first schools of ceramic engineering were established in the United States. The use of the term ceramics was then expanded to cover a much larger field the entire field of the silicate industries and products. At one time it was suggested by a limited number of ceramists that the term 'ceramic engineering' be changed to 'silicate engineering'. This proposal, however, gained little support and was soon abandoned.

Jan 1, 1945