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MR. J. F. MYERS, Consulting J3eneficiation Engineer, Greenwich, Conn.: In the written discussion contributed by Mr. F. C. Bond in item ( 2) (page 515), speaiking about the significance of the ratio of mill diameter to the make-up ball diameter, he states: "When this ratio exceeds 100 the power and capacity of the mill are de-creased"; and the paragraph ends with a reference to the 30 per cent ball volume "with some de-crease in mill capacity". I believe this broad statement is incorrect. When we are dealing with a non-cataracting mill, pre-ceded by a good rod mill, there is a slight increase in capacity, but the power does drop. The second point that I consider needs consideration is Mr. Bond's item (8), Proper Mill Speed (page 516). This paragraph should be qualified to cover single-stage mills only. It does not apply where a rod mill is followed by a non-cataracting ball mill. The statement as is, with no qualification, gives an erroneous idea of proper mill speeds.

Jan 1, 1957

By X. -G. Chen, K. Liu

Nowadays, great interests are rising on aluminum alloys for the applications at elevated temperature, driven by the automotive and aerospace industries requiring high strength, light weight and low cost engineering materials. As one of the most promising candidates, Al-Mn-Mg 3004 alloys is found to possess considerably high mechanical properties and creep resistance at elevated temperature resulted from the precipitation of a large number of thermally stable dispersoids during heat treatment. In present work, the effect of Fe contents on the evolution of microstructure as well as high temperature properties of Al-Mn-Mg 3004 alloys has been investigated. Results show that the dominant intermetallic changes from a-Al(MnFe)Si at 0.1 wt.% Fe to Al6(MnFe) at both 0.3 wt. % and 0.6 wt. % Fe. In the Fe range of 0.1 to 0.6 wt.% studied, a significant improvement on mechanical properties at elevated temperature has been observed due to the precipitation of dispersoids, and the best combination of compression strength and creep resistance at 300°C is obtained in the alloy with an intermediate Fe content (0.3 wt.%) with finest size and highest volume fraction of a-Al(MnFe)Si dispersoids. The superior properties obtained at 300°C makes 3004 alloys more promising for high temperature applications. The relationship between the Fe content and the precipitation of stable dispersoids as well as the materials properties has been discussed.

Jan 1, 2015

By Brian W. Mackenzie

The paper addresses five questions concerning the economic of gold exploration in the western Canadian shield. Can historical footprints be used to project future gold prices for exploration planning? Experience suggests that gold price forecast are too clo ely tied to current market events to provide meaningful guidelines. What range of breakeven gold price will typically be required to ju tify gold exploration in Canada? Minimum price requirements. initially asses ed at $540 to $1080 per ounce, probably lie in the range of $480 to $760 per ounce (expressed in 1985 Canadian dollar). Within Canada, what role do regional conditions and taxation policies play in determining the viability of prospective gold exploration targets? Striking interprovincial differences are found to exist, given the same geological circum tance -Nova Scotia, ew Brunswick, and Quebec rank towards the top in term of motivating exploration, Briti h Columbia provides the least investment incentive, while Saskatchewan and Manitoba place around the middle of the Canadian league. How can minimum acceptable tonnage-grade conditions for gold targets in the western shield be established and, then, constructively applied to provide exploration planning guidelines? Minimum target conditions, realis tically defined in terms of a broad band of doubt, can be used judiciously to help balance the direct costs of uneconomic exploration with the opportunity costs associated with rejecting economic deposits. How does the average cost per ounce of gold discovered in the western shield compare with the overall Canadian experience? Average discovery costs for the we tern shield, apprai ed at $100 per ounce, are shown to compare favourably with the Canada-wide record.

Jan 1, 1986

By Margaret Anne Stephenson

Today, in Australia, it is increasingly common to see agreements between Indigenous peoples and resource companies being achieved generally as Indigenous Land Use Agreements or agreements pursuant to the ?right to negotiation? process under the Native Title Act 1993 (Cth). Despite progress in this area, resource development on Indigenous lands is not without its challenges for both the resource proponents and the Indigenous parties. History demonstrates that resource development on Indigenous lands has produced struggles between the traditional owners of the land and the resource proponents. In Australia their relationship is generally defined by issues of access to land and assuring continued access to the land for the life of the project. In this context, divisions in Indigenous communities often emerge. The proposed resource project can have the effect of polarising members of an Indigenous community. It may be regarded by some traditional land owners as an advantageous opportunity for the community and by others as a hazard to country and culture. The process of agreement making has proved not only a test for the Indigenous community but also for the resource proponent. In this paper we undertake a contemporary case study of a proposed Australian resource related-development project on Indigenous lands. This project involved a multi-billion gas hub precinct proposed at James Price Point in the Kimberley region in Western Australia. The James Price Point proposal produced a litany of challenges for all parties. The traditional owners faced fundamental social and human rights issues, including a minority opposition to the project, the project's potential cultural heritage impact, the threat of compulsory acquisition of their native title interest by a State government due to an initial failure to settle an agreement, a fracture of their unsettled land claim and a minority rejection of the agreement ultimately reached. Additionally, the ?green? lobby also rejected the proposed gas hub on environmental grounds bringing the green lobby into direct conflict with both the traditional owners in favour of the project and the resource proponent. Ultimately, Woodside announced its decision not to proceed with the proposed gas precinct at James Price Point, in April 2013. In this paper we analyse the complexity of the James Price Point gas hub negotiations with the traditional owners which resulted in an Agreement that promised to deliver substantial benefits for the Indigenous communities. We question why such a favourable and beneficial agreement for the Indigenous community also produced the plethora of challenges and concerns and we consider how future negotiation processes could be better structured to avoid the difficulties that have confronted Indigenous land owners and resource proponents alike.

Aug 1, 2013

By Wignall. T. K., J. De Geoffroy

Statistical models are fitted to the observed distributions of eighteen characteristics of the population of commercial porphyry deposits of North and South America. The statistical base required for the formulation of the statistical models includes 58 commercial porphyry-copper-molybdenum deposits of the Cordilleran Belt from which geological, geometric and economic data were collected. Predictive and composite models are derived from the statistical study to assist explorat10n. planning, engineering studies and fmanc1al analyses as required for the development of new porphyry deposits in the Cordilleran Belt.

Jan 1, 1973

By Selwyn G. Blaylock

There is no more important problem today than industrial relationship, and probably none that is receiving more thought. But in these days of Epie and Utopia, one has to be rather careful in speaking on this subject. Consequently, for fear that my plea for taking the working man into the family might be misconstrued, by some, as a step towards communism or socialism, I would like to say at the outset that I believe that, so long as we have human individualism, human ambitions, human hopes and fears, straight socialism is as far off as the Millennium. The same applies to communism, which only differs from socialism in that the communist realizes that his ideals can only be attained by massacring millions and destroying all that we hold sacred. Each still looks to Russia for inspiration and guidance, totally disregarding the Soviet swing-back to individual contract work and differential wage scales. They seem to be oblivious of the tyranny and repression in the present Russian system, and get very restless when reminded of it. In spite of the fact that the standard of living in civilized countries has improved tremendously and is still improving, we find that, every seven or eight years, production in many lines has outstripped consumption, and we have had panics or depressions of greater or less magnitude, accompanied by extensive unemployment. It is evident to every thinking person that there must be no little inefficiency in the control of industry. For four long years, governments and industrialists have striven to find the key to solve the present problem. Many countries are getting back to a position approaching normal-Canada probably more so than most. None, however, can feel assured that they have actually cured the situation. All kinds of schemes have been developed; tariff barriers have sprung up over-night where none existed before; currencies have been inflated to gain added security in the home markets and to try to gain advantage in export trade; and each country watches the movements of the others with fear and mistrust. I am not prepared to formulate a full solution of our troubles, but I hope to be able to demonstrate the feasibility and wisdom of the type of industrial relationship I advocate, and also that it may be a large, and possibly an essential, step towards the solution of our difficulties.

Jan 1, 1935

By Paul Guliov

Industrial clays, including a variety of bentonites and kaolinbased clays in southern Saskatchewan are hosted by Late Cretaceous and Early Tertiary sediments. Ofparticular significance are the deposits of swelling bentonite in the Cretaceous Bearpaw Formation and the kaolinitic clays of the Cretaceous Whitemud and Paleocene Ravenscrag Formations. Swelling bentonite is currently produced in the Wilcox-Truax area by Canadian Clay Products Inc. and yields at least seven different commercial products for a variety of applications. Kaolinitic plastic clays, including ball clay, stoneware and earthenware clay, as well as kaolin in southern Saskatchewan, have a long history of development and use. Products include common and face brick, refractory bricks and other shapes, chinaware, pottery, sewer pipe, chimney flue linings and tiles. Currently clay production is for out-of-province brick manufacturing and for pottery. Recent research and improved technology combined with expansion in certain areas of the global clay industry generally hold promise for a resurgence of a clay-based industry in Saskatchewan. Products of particular promise include: clay tiles; kaolin fillers and extenders; and aluminum as well as related by-products from kaolinitic clays based on the carbochlorination process.

Jan 1, 2001

By David Scott, Denis V. Lachance, Daniel Marcotie

"LocationThe Heath Steele mine is located 50 km northwest of Miramichi, New Brunswick.Brief DescriptionHeath Steele is a 2700 t/d, copper-lead-zinc operation which employs conventional crushing, grinding, and differential flotation.HistoryThe Heath Steele mine is located in northeastern New Brunswick approximately 50 km northwest of the city of Miramichi and 65 km southwest of Bathurst. The massive sulphides containing ore values in zinc, lead, copper and silver were discovered in 1953 as a result of a joint venture between the American Metal Company and the International Nickel Company of Canada. The discovery was named after Mr. Heath Steele, manager of exploration for Amco at the time of the discovery.Mill production began in February 1957; however, the mine was forced to shutdown in 1958 due to depressed metal prices and metallurgical problems. It was re-opened in 1962 and milling operations resumed at 725 t/d until 1968 when the milling capacity was boosted to 1450 t/d and then to 2700 t/d in 1969.OreThe main ore zones are massive sulphides with very fine mineral grain. The chalcopyrite, galena and marmatitesphalerite occurrences are finely disseminated.Liberation is accomplished by grinding to 68% to 72% <400 mesh. Average mill feed assays are 0.8% to 1.2% copper, 1.8% to 2.5% lead, and 5.5% to 6.5% zinc, with 60 to 75 g/t silver."

Jan 1, 2000

By W. A. Lang

RESEARCH has been defined as the link between the present and the future. Science, wonderful though its achievements may be, has but scratched the surface of the unknown. Research is directing its attention to winning new facts in order that their application to the processes of today may open up new sources of wealth for the common benefit. Two classes of research investigations are often recognized-fundamental and applied, but these classes merge into each other and it is often hard to distinguish one from the other. Fundamental research is carried out primarily to develop basic facts, but frequently these are found to have immediate economic value, while applied research, specifically aimed at economic values, often necessitates a preliminary fundamental investigation. Both are essential and both should proceed by scientific method. It is obvious in fuel technology that a knowledge of the physical and chemical constitution of the various coals is fundamental to their industrial utilization, and further, a knowledge of the way these coals react under different conditions of temperature, atmosphere, etc., is necessary in solving such problems as storage, combustion, carbonization, gasification, or con-version to liquid fuels. The wide range of coals, the complexity, of their constitution, and the many uses for coal, makes fuel research no simple subject but one with unending possibilities. The Research Council of Alberta, formerly known as the Scientific and Industrial Research Council of Alberta, was established in 1919, to promote the development and conservation of the natural resources of the Province. The work of the Council was arranged in six major divisions: Fuels; Geology; Road Materials; Soils; Natural Gas; and Forest Products. The office and laboratories are located in the University of Alberta. The Council was financed until the depression of 1933 by a separate vote of the Legislature, but since then has been continued, though on a much smaller scale, as one of the activities of the University. It might, however, be noted that although the Council is now in abeyance, a skeleton organization has been maintained so that it can be brought back to active service as soon as conditions warrant. Annual reports are still submitted to the Legislature. Funds have not been made available, however, for the publication of the last five reports.

Jan 1, 1942

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 E. G. Bazeley

The paper reviews the scope, timing and financial impact of this significant project, which involves the supply and transportation of nearly 4 million tons per year of bituminous coal and lignite from sources in British Columbia. Alberta and Saskatchewan to Ontario Hydro&apos;s generating stations. The critical factors involved in the selection and utilization of these coals are discussed in relation to the three types of coal to be utilized initially. The paper then deals with each of the significant project elements to be undertaken by the various companies involved in the mining and movement of the coal, beginning with production at the mine through rail shipment to Thunder Bay, train-to-ship terminalling, shipment by lake vessel from there to the generating station, and finally blending the bituminous coal with United States coal prior to combustion. The review discusses the key features of the facilities involved in each case and the status and timing of the project elements , which are phased for the start of coal shipment by mid-1978. The paper concludes with some observations on the capability of the project to handle increased tonnage s and the challenges facing the movement in terms of quality , quantity and cost.

Jan 1, 1978

By F J. Pearce

The Steel Company of Canada, utilizing the S-L process, has produced partially and highly reduced pellets for use in the blast furnace. Experimental blast furnace tests, using reduced pellet burdens, have been carried out. The changes in production rate, fuel rate and general performance of both the S-L and the blast furnace processes are indicated. Introduction T HE ore burdens for a blast furnace may be improved in two ways: chemically, by concentrating the ore to a high degree of purity; and physically, by agglomerating or closely sizing the ore particles. Today, many b1ast furnaces are charged with closely sized agglomerates, some of which contain upwards of 66 per cent iron. The further improvement of these burdens by chemical concentration may, in many instances, be uneconomic due to the large losses of iron that occur during processing. Assuming that it would be possible to reject all of the gangue minerals, the maximum level of concentration of iron in the hematitic ores would be only about 70 per cent.

Jan 1, 1964

By M. Uszko

The climatic area in which Poland is located requires heating the ventilation air at intake shafts during the winter season. Air heating of the intake shaft should ensure safe operation of hoisting devices; while at the same time it also affects the conditions of the mine environment. The paper presents the issues of shaft heating in coal mines in terms of the mining law, the effect on the conditions of the mine environment and heating technology solutions used in the mines of Kompania Weglowa S.A. (KWSA).

Aug 1, 2013

By James Dickson

Brief History of Discovery and Early Development In the first half of the nineteenth century, the only authority on the Pacific coast between the Columbia river and Alaska was exercised by the Hudson&apos;s Bay Company, who had established a series of forts and trading stations on the coast from the Columbia north to Millbank sound. The Hudson&apos;s Bay Company were chiefly interested in the fur industry, and the large influx of settlers from the eastern United States into the territory now known as the States of Oregon and Washington, about 1840, not only interfered with the fur business but involved the question whether the territory should be under the British or the American flag. Anticipating the possibility, later realized, of losing control of this area, the Company, in 1845, established their main fort and trading centre on the southern end of Vancouver island under the name of Fort Camosun; shortly afterwards changing the name to Fort Victoria. Realizing that their former policy of discouraging all attempts to develop any other business than the fur industry had lost them several hundred thousand square miles, the Hudson&apos;s Bay Company now set about encouraging settlers in the vicinity of Fort Victoria by disposing of lands to suitable parties and also to those in the employ of the Company. The usual pioneering stage was passed through with the starting of small sawmills, grain mills, etc., and the incidental work accompanying such efforts. Any coal required for blacksmithing or other purposes was brought from England around Cape Horn by the few ships that visited the Pacific Coast. About 1849, an Indian who was having his gun repaired by a blacksmith in Fort Victoria asked about the "black stones" used in the fire and, on being told that the "black stones" had to be brought a great distance, he informed the blacksmith that there was plenty of the same stone where his people lived. This information was immediately given to an official of the Hudson&apos;s Bay Company who talked with the Indian and told him that if he would bring some of the "black stones" he would get his gun repaired free and a present of a bottle of rum. Nothing more was heard of this coal until April of the following year, when the Indian came into Fort Victoria with his canoe loaded with coal, which was tested and found to be of good quality. It is reported that the Indian got his bottle of rum.

Jan 1, 1935

By Richard Simon

This paper presents an ongoing study on the use of borehole breakouts to estimate in situ stresses at depth in a Canadian underground mine. Breakouts were identified using an acoustic televiewer (ATV) probe. Rock samples were tested in a laboratory to determine their failure curve. Breakout analyses were performed using a 2D failure criterion and a multiaxial failure criterion. Analyses were carried out using both short-term (peak) and long-term strengths (the latter considered here as being represented by the damage initiation threshold DIT). The analyses have shown that the use of the longterm strength and a multiaxial failure criterion leads to results that are more consistent with stress measurements performed in the field, in the vicinity of the mine.

Jun 1, 2012

By J. Zou

Open-cut method is most widely used for shallow utility lines installation. In urban areas, unexpected utility lines buried underground potentially turn open-cut construction into a highly risky operation, increasing the construction cost while presenting additional safety hazards. Examples include: breaking existing water main leads to flooding the downtown area; hitting an unexpected gas line causes an explosion. To prevent those accidents, the current practice is to stake out the underground utility lines before the open-cut construction based on the as-built information collected from various utility companies and government agencies. However, the as-built information is not always complete and accurate. To verify the locations of some important utility lines and protect them against damages caused by open-cut construction, new techniques and technologies are used but have their limitations in revealing underground utility lines, such as hydro vacuum method and ground penetration radars (GPR). The emerging technology of ultra-wide band (UWB) radar holds the potential to provide a cost-effective, non-destructive detection method. In this paper, a critical review of current practices and established methodologies is given. The functionality and working mechanism of UWB radar technologies are described. Application potential in open-cut construction is demonstrated by conducting lab experiments. Testing set-ups for detecting unexpected utility lines in soil along with preliminary results are presented. The effects of soil moisture content on the detection range are discussed. Research findings are summarized and constraints are discussed in conclusions.

Aug 1, 2013

By K. Esmaieli

The Synthetic Rock Mass (SRM) approach has the potential to capture the mechanical behavior of large rock samples. In order for the method to be used with confidence it is necessary to gain a good understanding of the factors that influences its analysis. This paper reports on a series of numerical experiments, based on field data from a large underground mine, to investigate the influence of intact rock mass strength of a constructed (SRM). A jointed rock mass defined by three fracture sets was simulated by a Discrete Fracture Network (DFN) model. The generated fracture network was subsequently embedded into six different intact rock samples, simulated by a bonded particle model in PFC3D, generating six SRM samples. Each intact rock sample was 7 m × 7 m × 14 m and assigned different mechanical properties. The first intact rock sample was assigned a uniaxial compressive strength of 205 MPa and an elastic modulus of 104 GPa with the UCS and elastic modulus values of the other samples downgraded by 10% until the weakest sample had a UCS value of 121 MPa and an elastic modulus value of 61 GPa. All SRM samples were loaded under uniaxial compression to obtain the complete stress strain curve. It was observed that the compressive strength of the rock mass samples decreased by 10% following the same trend as the rock material strength. However, the elastic modulus of the rock mass samples decreased non-linearly with reduction of the elastic modulus of the rock material. The Poisson&apos;s ratio of rock mass samples does not change with decrease of rock material properties. For the post-peak behaviour the results show that both the brittleness index and the residual strength of rock mass samples decreased as the rock material properties degrades.

Aug 1, 2013

By J. P. Harrison, R. Roostaei

"In this paper we investigate the consequences of using conventional triaxial peak strength criteria in the polyaxial stress conditions that occur around the end of a long circular underground opening. A series of 3d boundary element analyses were performed using Examine3D to determine the stresses induced around the tunnel in different in-situ stress conditions. To discuss the applicability of a triaxial strength criterion in failure prediction, strength factors were computed for both the Ottosen polyaxial strength criterion and the triaxial Hoek-Brown criterion. Assuming that the Ottosen criterion is an accurate indicator of strength factor, the discrepancy from this value due to the Hoek-Brown criterion is the error in prediction.In order to simultaneously show the error in prediction and actual strength factor, a quantitative bivariate colour scheme is used to visualize the results. This allows rapid identification of regions with large error, and where either unsafe or overly conservative conditions occur. We show how the inappropriate use of triaxial criteria rather than polyaxial criteria leads to an under- or over-estimation of strength factor, and can result in uneconomic or unsafe design. Extending the analysis to different in situ stress regimes shows how the in situ stress conditions affect the assessment."

Jan 1, 2015

By John H. Nicholls

In this paper, Imperial Oil Limited reports briefly on the drilling by contract rigs of twenty-nine slim holes in the Virden, Smiley, and Souris Valley areas. The investigations showed that slim-hole penetration rates, as a result of careful control of drilling variables, can approach those achieved with 7 7/8-inch bits. It is concluded that slim-hole drilling is acceptable for development or exploratory work. Imperial also reports on the completion techniques and equipment that have been developed on twenty-seven tubingless 2 1/2-inch casing completions. Indications are that the method is economically desirable where excessive gas or water production is not anticipated.

Jan 1, 1958

By Z. D. Hora

"There has been a number of new developments in British Columbia&apos;s industrial minerals field over the past few years. Several new industrial operations were started to diversify the line of British Columbia mineral production by magnesite, perlite and fuller&apos;s earth. Industry activities and geological projects have identified occurrences of rare earth minerals, niobium, kaoline, fireclay and zeolites. The Geological Survey Branch significantly improved its database on industrial minerals. New geological concepts based on recent work are opening a number of new opportunities f or further industrial minerals&apos; exploration and development in British Columbia.IntroductionTraditionally, the value of industrial minerals produced in British Columbia in any given year comprises between 100/0and 15% of the combined value of minerals, coal, petroleum and natural gas. Over the years a wide variety of industrial minerals has been produced , often with different levels of marketings success. For some products, such as dimension stone and clay or shale products, initial strong demand gradually dissipated; for others such as asbestos and magnesite, new discoveries or new industrial activities created demand and new markets . In some cases, such as fluorite , talc, pyrophyllite and perlite, wider use has been prevented by small size, poor quality or remote location of the deposits. Also, British Columbia , with 2.6 million inhabitant s, provides only a limited market and the industry therefore has to look beyond provincial borders."

Jan 1, 1990