Search Documents

By J. S. Stacbulak

"The main ventilation design features adopted at Inco to safeguard personnel against the effects of fires are described in this paper. Measures taken to prevent and detect fires due to spontaneous combustion, and fires involving conveyor belts, are described in detail.IntroductionConsidering the over-all picture of present-day mining operations, the expenditure required to provide a proper system of mine ventilation and fife control should be regarded as a sound investment that will pay back in increased mining efficiency, improved safety, health, and morale of the miners.Mine ventilation control and mine fife detection and fighting are inseparable, because a ventilation system can spread deadly products of combustion just as efficiently as it does life-sustaining oxygen. Therefore, the possibility of a mine fife occurring is of particular concern.The flirt objective is to prevent a fife. The second objective is to design the ventilation system so that a positive fresh air supply can be ensured on each main level regardless of the location of the fife. The third objective is to be able to detect the fife at an early stage and to extinguish it before it can develop into a major fife.Accordingly, at Inco, very extensive measures are taken to prevent fires and to locate, isolate and extinguish them rapidly. To obtain an early warning, it is not sufficient to know that a fife has started, but it is also necessary to know where the fife is burning."

Jan 1, 1994

By B. Bichel

For the last 70 years, molten blister copper has been transferred by rail in hot metal cars from the Copper Cliff Smelter to the Copper Cliff Copper Refinery (ex Ontario Refining Company) where it was processed in two (2) reverberatory anode furnaces by poling with logs, cast on four (4) wheels, and then electrorefined. This practice was modernized in 2001 with the installation of two (2) rotary anode furnaces at the. Copper Cliff Smelter which employ steam and. natural gas for reducing and which provide a significant reduction in emissions. A new casting shop with a single anode casting wheel is used to cast regular and stripper constant weight anodes which are transported by truck to the Copper Cliff Copper Refinery for anode preparation and electrorefining. This paper provides an overview of the copper circuit at the Copper Cliff Smelter and a description of the CDN$31 million capital project.

Jan 1, 2002

By R. Vergunst, E. A. Devuyst, G. Robbins

"INTRODUCTIONThe Inca process for continuous cyanide removal from industrial wastewaters was patented in 1984 by G.J. Borbely, et.al. (1). The process requires SO2, air, lime and a copper catalyst. Both free and complexed cyanide are oxidized to cyanate in the pH range 8 to 10. Cyanide bound to iron is removed by precipitation as a ferrocyanide insoluble salt and other base metals are removed as hydroxides.The process was piloted in 1982 on barren bleed solution at Campbell Red Lake Mines Ltd., Ontario (2). Since 1982, the Inca SO2-air cyanide removal technology has been applied in twelve commercial installations. The process has significant advantages over other commercial processes in the completeness of cyanide removal and lower reagent requirements and costs.COMMERCIAL INSTALLATIONSBy the end of 1988 Inca will have applied its patented cyanide removal technology to twelve commercial operations. Three of these, namely Scottie Gold Mines, Dupont of Canada Expl. Baker mill and Carolin, all in British Columbia, Canada, have ceased cyanidation operations but SO2-air cyanide destruction results were good for all mills, particularly so for over two years for the Scottie mill.Removal of cyanide from CIL slurry tailings is applied at Equity Silver (9,500 tpd) and Inca's new 1,200 tpd mill at Inca/Golden Knight. Detoxification of CIP tailings is carried out by Colosseum California (3,600 tpd) and Canamax's Ketza River operation (360 tpd). Repulped tailings from Merril-Crowe flowsheets are treated at Total Erickson's Mount Skukum mill (300 tpd) and Skyline's Johnny Mountain mill (200 tpd) and barren bleed at Inco/Queenston's McBean mill (500 tpd). Lynngold's MacLellan mill (1,800 tpd) treats pond supernatant water. Plating shop cyanide effluents are decyanized at Kuntz Electroplating in Kitchener, Ontario. Many of the above commercial operations were described in some detail in previous publications (3,4). Typical installations are described in this paper. A summary of operating results is given in Table 1."

Jan 1, 1989

By Robert T. DeGavre

The $650 million financing for Into Ltd.'s Soroako nickel project is a story worth telling-not only because the project itself represents a significant achievement but also because there are certain important lessons that can be derived from our experience in financing the project. A critical appraisal of the methods and successes in the financing plan is presented in this article, in light of goals which Inco sought to achieve. A technical assessment of the project is not included, since Inco Ltd. has submitted a series of papers on this subject at the International Laterite Symposium as part of the 108th Annual Meeting of AIME in February 1979. Progress in developing and financing the project is encapsulated in the accompanying project factsheet.

Jan 3, 1979

By R. A. Roberti

Most copper refineries use conventional wheel systems to cast anodes. over a period of time the copper moulds that are used become warped and cracks develop. To control mould warpage, the mould's are either rejected after a certain warpage is reached, or the shape is restored by mechanical means. The cracks, unless they are very severe, are repaired by a peening process. Even with regular maintenance to control warpage and cracks, the moulds have a limited useful life. If warpage and cracks are not controlled, anode quality deteriorates and tankhouse operations are seriously affected. -An intensive study was initiated to develop means of controlling mould warpage which culminated in the d?evelopment of technology to control mould warpage to within ±1. 5 mm, and at the same time effectively contr0l: cracking and significantly increase the mould life-. The warpage control has been achieved by using a unique mould design. Mould cavities are present on both sides of the mould and periodic inverting controls the wa-rpage in the cavities. The mould casting procedure has been developed and all production wheels have been converted to the new mould design. The performance characteristics of these moulds will be detailed. 21

Jan 1, 1987

By Henry B. Fernald

THE Federal income tax treatment of expenditures for exploration and development for mines and other natural deposits (other than oil and gas) was materially changed by special provisions of the 1951 Act that are continued in the present 1954 Code." These present provisions for mines in stance they are the same as the 1951 amendments to the 1939 Code, Secs. 23 (cc) and (ff), respectively, except that for exploration the allowable annual deduction is increased to $100,000 (from $75,000) and minor changes in case of property transfers are made with respect to the four-year limitation. Before 1951 the statutes made no specific pro- visions regarding development and exploration for mines, but the rules were prescribed by Treasury regulations: 1) Before the mine entered the production stage, all development and exploration expenditures for mines, less net receipts, were to be capitalized recoverable through depletion or written off as losses when determined worthless. 2) After a mine entered the production stage, development expenditures were deductible as expenses-currently if ordinary expenses, but on a deferred basis if extraordinary in scope. This recognized the two separate periods, one before and the other after beginning of the production stage. There was no distinction between an exploration and a development period, but exploration was included as part of development.

Jan 1, 1958

By Robert B. Parsons

"Once all the hullabaloo about Finance Minister Wilson's April 27 budget died down (or was it an April 26 budget?), the pain of the budget papers began to sink in. Individuals and corporations will have to dig deeper and pay more taxes - and government will continue to dig deeper and spend more. The irony of the situation is that higher tax rates actually make flow-through shares more attractive as a tax-deferral investment - a bittersweet ""bravo"" for the mining industry.INTRODUCTIONFor the first time in Canadian history, a major budget address has taken two days to deliver. Of course, it's not a case of long-windedness, but rather a case of a hastily called press announcement on April 26 in response to a budget leak, followed by a formal budget speech on April 27.The general reaction of the business community to the budget was to the effect that the tax hikes are acceptable, but the government's failure to curb spending is less than acceptable. Mr. Wilson's reported response indicated that the government had never promised to cut spending, and that increased government spending would actually benefit the country. That age-old debate will doubtlessly continue for generations.In any event, three noteworthy components of the budget papers are:• Personal income tax rates increase effective July I, 1989;• A ""large corporations tax"" (in effect 'a corporate ""minimum tax"") is effective July I, 1989; and• Federal sales tax increases are effective from June 30, 1989, to be replaced by a national sales tax in 1991.A brief overview of these and other budget proposals follows."

Jan 1, 1989

By J. H. Zietsman, M. W. Erwee, Q. G. Reynolds

Pyrometallurgical furnaces, essential for metal extraction, operate at temperatures exceeding 1600°C and represent complex multiphase systems that challenge direct industrial research. Multiphysics models play a key role in shedding light on their intricate behaviours, supporting the refinement of design and operational strategies. Integral to the operation are the tap-holes, which facilitate the removal of molten products and are routinely opened by lancing, a process comparable to the use of a cutting torch, where high temperatures result from oxygen reacting with an iron lance. When the lance pierces the clay, oxygen gas enters the furnace, which could influence the behaviour of the molten material inside. In this work, a multiphase fluid flow model was used to investigate bulk flow dynamics, with a focus on the effects of the lancing process on the inside of the furnace, immediately behind the tap-hole. Incompressible and compressible multiphase fluid solvers were used and compared with respect their performance – the intention was to assess whether using a compressible solver would yield a different solution to the incompressible one. It was concluded that there are negligible disparities in bulk fluid flow behaviour between the solvers for the case studies examined, indicating that solver selection might be less consequential for certain aspects of oxygen lancing.

Apr 16, 2024

By R. J. R. Cornelissen

The elimination of the incidence of silicosis in employees in industries such as mining and pottery is an ongoing international initiative. After many decades of industrial activity in these industries and many dollars spent on preventative measures, silicosis is still occurring. The exposure-prevention measures taken so far have certainly improved the working environment dust concentrations; however, the illness is still regularly diagnosed in workers. More funding is needed for interventions to improve working conditions. Many aspects of dust prevention and suppression will be researched and exposure assessment methodologies and equipment will need to be reviewed for the purposes of improvements in effectiveness. This paper presents results from laboratory tests carried out on gravimetric sampling pumps and cyclones. It highlights the erratic flow produced by gravimetric pumps of three different manufacturers who claim their respective pumps are equipped with flow stabilisers. The standard BS EN 1232:1997 is used as a basis for the tests. A method, albeit impractical for fieldwork, is shown for the elimination of the pulsation in the flow. This method serves to prove the method and protocol used in this study. The pressure loss caused air-flow resistance of cyclones is measured. The air inlet aperture size of cyclones is measured. The large discrepancy in the two criteria between individual cyclones is shown. The paper concludes that all the pumps tested failed the prescribed limits of BS EN 1232:1997 regarding the pulsation of the gravimetric sampling flow. The difference in flow characteristics of the cyclones, together with the erratic flow produced by the pumps, throws into question the accuracy of the exposure assessments. It is suggested that substantial resources be channelled towards solving these flow problems in parallel with measures taken to reduce exposure. In principle, the accurate assessment of exposure and dust concentration levels is a prerequisite for effective management of the problem of silicosis.

Jan 1, 2009

By Balmer Neilly

To one with so little experience in matters pertaining to currency, international finance, and foreign trade, this is surely an ambitions venture on my part. However, this is a subject of prime importance to all seriously minded Canadians and, if we are to obtain any clear understanding of the factors involved, we must study the facts and debate such points as may remain at issue. During the last few years, the world' s better known economists have described the gold standard in all its ramifications and in such detail as to leave many of us even more confused than before. If we, then, are to acquire any real conception of its meaning and use, I think we must reduce it to its fundamentals and start from there. To my way of thinking, gold in ? trade and commerce is the symbol of honesty. When you seek to discharge a debt by tendering paper you hand the recipient an I.O.U. which may or may not be good, for the purchase of goods or services to the extent of its face value. When, however, you discharge a debt by the payment of gold, it constitutes a complete and final discharge. There are no reservations - no ifs and ands - and the transaction is definitely closed to the satisfaction of all concerned. Gold, then, is evidence of accumulated and transferable wealth that is immediately acceptable in practically every part of the world. However, there is not nearly enough gold to meet the demands of world trade, and. many years ago this deficiency gave rise to what we now describe as our banking system.

Jan 1, 1949

By S. V. Rungan

Since 1994, South Africa has been the subject of international attention, especially in regard to its transformation initiatives, which aim to redress the post-apartheid imbalances. Mining, as a major employer and one of the major industries in South Africa, has been the focus of the government?s Black Economic Empowerment initiative with the introduction of the Minerals and Petroleum Resources Development Act and the Broad?Based Socio?Economic Empowerment Charter for the South African Mining Industry. The historical background to South Africa?s transformation and the role of the mining industry are pivotal to an appreciation of certain aspects of the Minerals and Petroleum Resources Development Act and the Broad?Based Socio?Economic Empowerment Charter for the South African Mining Industry. The issues around Black Economic Empowerment and the enabling of a smooth transition to the South African mining industry of the future are explored in this paper.

Jan 1, 2005

By Y. S. Roditis

A new method for interpolating a block model is proposed, where both the diamond drill holes (DHs) and blast holes (BHs) data are used. Combining these data types poses a geostatistical "class size" problem due to the different statistical properties of the densely populated BHs and the sparsely populated DH data. This paper discusses how linear regression was used to adjust the DH values prior to the interpolation to account for the "class size" problem which is inherent to the procedure. The correlation between the BHs and the DHs is found. The DHs are then corrected based on the regression line. Each block that falls within a certain range of influence of a blast hole is assigned a different code and is interpolated with the combined BH and regressed DH data set. Blocks that fall outside the range of blast hole influence are interpolated using the original DH data set. A comparison against other methods, indicate a 12% improvement over using DHs only and a 2% improvement over using BHs only.

Jan 1, 1992

By S J. Schafrik, M Long

There are several factors that are increasing the need for new graduates to be ready to design and manage more autonomous operations at mines. Autonomous controls and systems range from the start-up, control, and shutdown of processing plants to the autonomous operation of vehicles. These operations require the workers, engineers, and management to have additional skills for programming, debugging, tasking, and maintaining the equipment. The future survivability of many mining operations will be influenced by a company’s willingness and ability to understand, accept, and utilise this technology for safe and productive operations. This is an educational opportunity and challenge that needs to be addressed throughout the student’s experience, from first year to graduate level. This paper discusses the lessons learned from a decade of multidepartment effort at all student levels and many courses that are able to incorporate data science, controls, and autonomous design into the already topic-rich national curriculum. This approach also exposes other engineering disciplines to the mining industry which is a valuable recruiting tool for talent outside of the mining engineering departments.

Sep 1, 2024

By A. Anani

The need to optimize surface mining operations has led to the use of discrete event simulation (DES) modeling of truck-shovel systems. Often, these models assume truck cycle times are independent and identically distributed (iid) random variables, although, with significant bunching on the haul routes, this may not be valid. The objective of this paper is to present a methodology to (i) account for truck bunching due to slow trucks; and (ii) test for cycle time dependence (i.e. whether truck cycle time data is iid or not). We built a DES model that accounts for bunching due to a slow truck(s) and used the cycle times as data for further analysis. We then tested for cycle time dependence using Pearson correlation coefficients. The results show significant correlation of truck cycle times for different number slow trucks, with variable speeds. Assuming iid in modeling results in over-estimation of productivity and the uncertainty surrounding it. The over-estimation of uncertainty is pronounced when the relative difference in truck speed increases. The confidence interval of the means of truck loads/shift decreases with increasing number of slow operators. This work extends the usefulness of DES in truck-shovel applications.

Feb 27, 2013

Advances in technology have led to larger and deeper open pit mines and, consequently, also increased the potential economic impact associated with slope failures. If the ultimate aim of mining operations is to maximise project profit, it is surprising to see related research activities have mostly been focusing on technical areas such as slope stability modelling, but with limited studies conducted to date to assess the relationship between geotechnical uncertainties and economic risk. Given most major decisions in the mining industry nowadays are made by management staff with financial background, any design approach that would help to link slope stability analysis results with monetary values would no doubt enhance communication between geotechnical practitioners and decision makers. This paper presents a study which assesses economic impact of slope failures to assist in mine planning. The study also estimates the impact of slope failures on project value, which would enable economic risks associated with pit slope designs to be closely examined. The proposed risk assessment techniques, used by financial institutions for many years to assess portfolio risks, can assist geotechnical practitioners in quantifying risks of slope failures. Risk-adjusted concepts are also suggested to assist management in selecting a slope design with optimal risk and return ratio.

May 1, 2010

By E Holloway

The optimisation of an open pit mine can be broadly split into two stages, the first being the ultimate pit optimisation (and subsequent stage designs), and the second being schedule optimisation. Macroeconomic uncertainty clearly impacts on both however interrelationships do also exist. Generally, the opportunity exists for the ultimate pit to be revised during each planning cycle, however when this reprieve is removed the uncertainty for the underlying business increases. As one example, the introduction of an in-pit waste dump can be seen to significantly limit the option to revise the ultimate pit. When in this situation there are two potential risks that present: (i) the long-term price used for the ultimate pit selection is optimistic, and too large of a pit is selected resulting in waste being mined which uncovers material not of a significant value to deliver a profit; (ii) the long-term price used for the ultimate pit selection is pessimistic, too small of an ultimate pit is selected, and ore of realisable economic value left behind. Both of these outcomes are risks and as such can be assessed and quantified. CITATION: Holloway, E, 2018. Incorporating economic variability into a strategic planning framework, in Proceedings Complex Orebodies Conference 2018, pp 88–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Rodrigo Peroni, Euler Victoria

Knowing the depth of contacts between weathering zones in phosphate mines is determinant to define the stripping ratios and the mineralized zones. Contacts are gradational and difficult to define even in the drillhole samples, so the combination with geostatistical simulation techniques helps to define the contact zone and the grade distribution, providing a way to assess the probability of the occurrence and the positioning of contacts between the barren waste and the ore zones. These inputs are used in the scheduling, anticipating risks associated with mine planning scenarios. The results from an application to a case study showed a good improvement when compared to traditional techniques.

Jun 25, 2023

By R. C. Warner, L. Mills, S. D. Botts, M. Marticorena

The Antamina Mine is located in the mountainous region of the Ancash Department of Peru at an elevation of approximately 4200m.The 120 km main access road crosses the headwaters of numerous high-value trout streams and is adjacent to pristine lakes, some of very high ecological and scenic value. In addition, the mine discharges mine water and tailings supernatant to the Antamina and Ayash watersheds. These streams provide the primary water supply for irrigation by local residents and provide excellent fishery habitat. The rock walls and earthen diversions constructed by historic and current indigenous residents of Peru are world-renowned and local residents continue this tradition, passed down from the Inca Civilization, for both agricultural purposes and water distribution. The key elements of sustainable development – economic, environmental and social development have been incorporated into Antamina’s sustainable development program through integration of indigenous knowledge and capabilities into enhanced storm water, erosion reduction and sediment control systems. Examples of incorporating indigenous technologies and knowledge into cost-effective and environmentally sound environmental controls are:(1) placement of rock walls on steep terrain to reduce slope length and erosion, (2) installation of rock walls (porous rock check dams) within elongated sediment ponds to increase detention time, (3) construction of rock-lined ditches to convey clean water (4)use of rock walls, with or without geotextile, to function as a seep berm, and (5) appropriate selection and usage of native Andean species for protection of canals and sediment ponds, and steep slopes.

Jan 1, 2004

Flotation of a mineral bearing particle is the result of successful completion of a chain of events, such as, producing particles with sufficient exposure of the valuable mineral on the surface, reagent adsorption, suspension of the particle in the pulp, collision of particle with air bubbles and subsequent attachment, ascending to the froth column and transport to the concentrate stream, among others. These sub-processes in turn are affected by the feed properties such as size and density, and process variables such as size of air bubbles, degree of turbulence in the cell, particle/particle interactions etc.. Thus, inefficiencies occurring in any one or more of the above processes will result in inefficient flotation performance. In spite of its dependency on a wide variety of sub-processes, flotation performance is commonly modelled based on first order kinetics using two or three parameter models. As the model parameters may be affected by several of the sub-processes mentioned above, interpretation of their variations and identifying the specific causes is extremely difficult. Of the many factors that influence the flotation performance, liberation information of the particles such as the grade distribution and surface exposure are considered vitally important. In this paper, it has been demonstrated a) how a predictive liberation model may be derived and used in quantifying the liberation information of the particles produced at various grind sizes and b) how the flotation process may be modelled by explicitly incorporating the liberation information, thereby improving the accuracy of the model. Comparisons of the observed data with the proposed model and those of published liberation/flotation models have also been made.

Jan 1, 2016

By Free. Michael L.

Crushing ore prior to heap leaching enhances mineral liberation and creates fine particles that may require agglomeration to avoid permeability problems during leaching. Conventional modeling is relatively successful in describing general fluid flow and extraction in heaps. However, most models do not adequately account for the effects of mineral liberation and exposure or the effects of agglomeration, curing, and loading on heap leach performance. This paper will discuss methods to account for mineral liberation and exposure as a function of comminution. It will also discuss methods for incorporating liberation, exposure, and mineral locking as well as curing and fluid flow in heap leach modeling. It will also provide information regarding agglomeration and the effect of loading in heap leach modeling.

Jan 1, 2014