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By Mory Ghomshei

Pebble Creek Geothermal Power project is associated with a massive recent volcanic eruption in Southwestern British Columbia Canada. Slim holes drilled to depths 1100 m in the prospect area, show very high temperature gradients around 80?100?C/km. The temperature and chemistry of the Pebble Creek hot springs indicate the possibility of a steam reservoir in the prospect area. In addition to high temperature gradients, presence of host rocks with high permeability, along with abundance of recharge waters (from the Lillooet River) provides clear signature of a high-grade geothermal power reservoir at depth 2000 to 3000 m. Data show that over five hundred Megawatt of green power can be generated from the prospect area in a commercially viable manner. The generated power will be base-load, which in comparison with large hydro has the advantage of lower capital costs and a significantly smaller footprint. The final hurdle to overcome, before starting the development phase, is deep exploratory drilling for resource confirmation. This paper is a summary of the data available on the Pebble Creek geothermal power prospect, presented in the context of viability of the resource for large-scale commercial power generation.

Aug 1, 2013

By Kati Tschöpe

Cathode wear has become an increasing challenge in the aluminum industry due to the use of more graphitized materials. Today, there exist no standard laboratory methods for measuring cathode wear where different commercial materials can be ranked. The typical average wear rate in an electrolysis cell is quite small. The aim of this work was to design a test method where the wear could be accelerated compared to industrial cells. It was focused on polarized tests where the cathode is exposed to electrolyte, which gives higher aluminium carbide solubility. The cathode materials were characterized by microscopy and image analysis.

Jan 1, 2011

By A. K. Debnath

The water resource is key to survival of the mankind and this resource is now becoming critical in many parts of globe including India. As per an assessment of Central Ground Water Board (CGWB) of India, a huge shortfall of about 58 billion m3 of water is anticipated by the year 2050. In order to counter this shortfall, there is thrust from Government of India to adopt water conservation measures. National Environment Policy, 2006 of Government of India also stresses upon the need to take up water conservation measures for water security of the country. The coal mines in India provide an excellent opportunity to take up water conservations measures therein. The mine water is not acidic unlike western countries and it conforms to the prescribed regulatory standards. This nature?s gift is utilized in Coal India Limited by allowing mine voids to get filled with mine water. The net recharge potential of the opencast mining area is found to be about 5% in comparison to 2% in non-mining area offering good prospects for ground water recharge. The seasonal rainwater is also diverted into mine voids left at the end of mining operations which act as huge reservoirs/ pit lakes for storage of the water. They also serve as surface water bodies for recharging of water table in the surrounding areas. The area and space left from where coal has been extracted completely in underground mines and will not be entered by any man or machinery after the extraction, called goaf, are also potential source of water conservation. These additional water resources created are being utilized for meeting the industrial, domestic, irrigation and other requirements of the projects and local communities eliminating the need to tap other fresh water resources including ground water. Presently, 75% of the water demand of the coal mining project is being met from the water stored in the mine pits. In future, CIL is likely to create about 3.3 billion m3 of water resource, on an average, in its opencast mines alone. In the mine closure plan of opencast mines, the last cut is proposed to be developed into water body for recharge of ground water and creating additional water resources. A clean potential source of potable water is thus developed after mine closure. This will ensure water security of the country.

Aug 1, 2013

By Marc Piard

In a cool mine, tapping high-pressure lines through reducing valves lowers the temperature beyond remedy. It is the writer's suggestion that, for low-pressure work, law-pressure air ,should be generated in a compressor installed underground adjacent to the work, and that the jacket-water of the compressor should be utilised for re-heating purposes. Such a system of compressed air distribution, designed especially for service in cool mines, is described in the following notes. The suggested system includes a three-wire pole line from the sub-station to the opening nearest to the working face, with a cable connection extending to the latter from the openings; an electrical centrifugal unit; a reservoir excavated in the ground; and a distribution line, re-heated by jacket-water. As regards the reservoir, it may be pointed out that in many mines there are blind or abandoned tunnels that could be used for the purpose. The centrifugal type of compressed air machine is a comparatively new departure, and it was formerly considered that such a machine, operating at less than 1,000 kilowatts per unit, would be commercially impracticable. At the present time, however, these machines are being built in Europe for as little as 400 kilowatts per unit, and as much as 110 lb. per sq. inch pressure. One advantage which these centrifugal machines have over other types is that they may be driven by plain induction motors, without the help of special starters-a consideration of the first importance where the electrical regulations are severe.

Jan 1, 1926

By C. R. Kato, G. Proulx

"Within the continuous scenario of reduced aluminium price and plants production costs increase, the energy consumption optimization in the aluminum electrolytic pots continues as the main focus for the producers. Energy consumption was chosen as a key performance indicator to drive the efforts and actions for improvements. Alcoa improved the energy consumption by approximately 3% from 2005 to 2015. This improvement was a result of best practices implementation, new technologies introduction, strategic actions with plant curtailments and management practices. The main objective of this paper is to highlight the importance of the management practices for planning and operational improvements beyond the technology changes. About 10 years ago, Alcoa reorganized its approach to retain knowledge in the Smelters by using a Best Practices format. For each specific subject, a skilled team defined the minimum requirements and the Best Practices for several aspects of operation and maintenance, which affect the environment, safety, cost, customers and performance. These Best Practices were deployed to all Smelters combined with training sessions to process and operation professionals. We will describe how the Best Practices were organized, the deployment strategy used, and the approach to measure the plants’ success. We will describe the management approach that includes Manufacturing Analyses focused on 3-year potential, annual planning, and weekly monitoring of plant stability. A manufacturing analysis is organized at select plants with cross-functional participation of specialists from technical, operational, procurement and finance. The output of a manufacturing analysis includes a roadmap of enablers to improve energy efficiency. A quarterly follow-up of enabler deployment is held with the plant and resources that participated in the analysis. Annually, there is a Planning Process where energy consumption enablers are selected to be implemented during the next 3 years for each plant. A monthly critical analysis is made by the plants with regional best practice support. On a weekly basis, key performance indicators are reviewed with determination of a stability index for each plant. Any deviation signal of unstable condition is alerted and supporting resources are diverted to the plant to reverse trend with countermeasures.INTRODUCTIONDue to factors like excess aluminum in the market and lower consumption in China, the LME price is declining along the last years, as showed in Figure 1. In 2011, the price peaked at US$ 2,400/ton and since then, continues to trend down and approaching the lowest level at US$ 1,500/ton in the last 5 years."

Jan 1, 2016

By T. Guan, G. Fu, X. Zhou, L. Deng

"One kind of tailings from gravity separation of polymetallic mine contains 0.5–0.8% SnO2. The proportion of –0.037 mm size fraction of the tailings is 37.12%, and the distribution rate of SnO2 is 60.32% in it. For this tailings, two processing technology was carried out. One was felt-shaking table gravity separation in which the concentrate with a grade of 30% SnO2 at a recovery of 10% was obtained. Another was flotation-gravity separation in which the concentrate with a grade of 51.20% SnO2 at a recovery of 51.69% was obtained, but the dosage of collectors was as much as 990g/t. Therefore, the experimental research on the influence of grain size composition on the cassiterite recovery were conducted. The results show that: (1) the flotation recovery of the cassiterite distributed in +0.043 mm size fraction is only 10%, flotation recovery is not suitable for it; (2) a portion of cassiterite distributed in –0.01+0.005 mm size fraction could be recovered by flotation, but the tin flotation performance will be worsened rapidly and the dosage of collectors will be increased due to the increase of the content of –0.010 mm size fraction; (3) flotation processing is not suitable for –0.005 mm size fraction of the tailings. According to the results, a new technology has been carried out, that is discarding tailings by gravity separation-hydrocyclone desliming-flotation-gravity separation processing flow. The processing index is close to that of the flotation-gravity separation processing flow, and the collector dosage is decreased to 360 g/t by this processing technology. And, it has been achieved that the cassiterite slime is recovered economically and reasonably.INTRODUCTIONAs the density of cassiterite is higher than that of gangue, gravity separation is considered to be a low cost, pollution free, and effective process for cassiterite recovery (Wills, 2009). However, cassiterite is a kind of fragile mineral, over crushing is easy to take place and a large amount of slime is inevitably produced in the crushing and grinding of cassiterite. For the cassiterite slime exists in –0.043 mm size fraction, the efficiency of gravity separation decreases sharply. The production practice shows that, for the fine cassiterite, the recovery of tin exists in –0.043 mm +0.010 mm size fraction is about 13% through shaking table gravity separation, and the tin exists in –0.010 mm size fraction is almost impossible to be recovered by gravity separation. If flotation is adopted to recover fine cassiterite, the problems of high reagent dosage, high cost, environmental pollution, and poor economic benefit would take place. Therefore, the recovery of cassiterite slime is a worldwide problem. A key way to increase the utilization of tin resource and increase the economic benefit of tin mines is developing suitable beneficiation process for fine cassiterite."

Jan 1, 2016

By Franc R. Joubin

"Gold has been found in many parts of the Bridge River district of British Columbia; but it is from a relatively small area in the valley of Cadwallader creek that most production has come. The ore-bearing area measures 1/2 mile in width by 3 miles in length; and for convenience it is called the Cadwallader gold belt in this paper. In this belt are found the Bralorne and Pioneer mines and in addition several prospects under development.The gold of the Cadwallader gold belt occurs in quartz veins averaging about 3 feet in width and containing about ½ oz. of gold a ton. Except for a relatively small amount of silver, no other metals are produced from these veins. The ore-bearing veins occur in a variety of rocks. They occupy reverse faults and tension fractures belonging to a distinctive fracture system. Some of these structures are ore-bearing over lengths exceeding 5,000 feet and depths exceeding 3,700 feet. The production of the Bralorne mine (1932-1945) is 996,383 oz. gold and 190,709 oz. silver; that of the Pioneer mine (1930-1945) is 777,588 oz. gold and 135,698 oz. silver. These two mines have together distributed about $25,000,000 in dividends.The Bridge River district first attracted attention in 1863* when prospectors were attracted by its small but rich placer gold deposits. Most of the important lode deposits of the Cadwallader gold belt were discovered in 1897 (11). Many years of desultory development followed and it was not until 1928 and 1932 that the Pioneer and Bralorne mines, respectivdy, entered into profitable production."

Jan 1, 1954

By J. B. Kwon

For improvement in the productivity of tall building projects, table formwork is one of the main methods that have been adopted for slab formwork. Because the table formwork method is an equipment-oriented construction method, the type of lifting equipment and method of operation considerably affects the productivity and cost of the table formwork. It is also important to make an equipment input plan for completing the table formwork within the time given, according to the structural construction cycle. For performing the table formwork, a tower crane or an independent lifting system, and shifting trolleys, are required. However, if an inefficient equipment input plan is made, exorbitant cost may be incurred. Therefore, the purpose of this study is to analyze the productivity of a table formwork, considering the type and number of lifting equipment and the number of trolleys inputted, and to suggest quantitative data for making a cost-efficient equipment input plan within the construction duration given. It is expected that the results of this research will be utilized as a basis for cost-efficient equipment input planning.

Aug 1, 2013

By S. Duvah Pentiah

The transformation of an open pit coal mine to a horizontal-punch underground mine is subject to a number of challenges. These include scheduling the operation of various sizes of trucks over a long period, as well as updating delivery routes and dump site locations as the mine transformation progresses. In this process, rock is excavated from a quarry through earthworks. The bulk earthwork and quarry material delivery were initially drawn from traditional planning and experienced issues in their early phases. As a result, a traffic simulator was developed in order to validate schedules and predict achievable throughput, likely delays or blockages in the long term. The dynamic traffic simulator was also used to provide traffic density and vehicle arrival data at selected intersections in order to identify possible safety and efficiency issues.

Aug 1, 2013

By Xu Wang, Yizhe Zhang, Yangge Zhu, Xiao’ou Xia, Fangming Liu

"The progress of lean magnetite preconcentration in China was introduced in this paper, such as using coarse crushing to reject tailings, and multistage grinding, multistage magnetic separation. The applications of “more crushing and less grinding” process and equipment in lean magnetite preconcentration could reduce production costs effectively. The related analysis and study on concrete cases were carried out in this paper.INTRODUCTIONIn the case of the slowdown and weak recovery in the global economy, bulk commodity prices fell sharply in 2015. Take iron ore's prices for example, about 60% grade iron ore's import prices in China from about $65 per ton at the beginning of 2015 fell to about $42 per ton in the end of the year, down by about 35%. But iron ore resources are non-renewable resources, with the continuous development and utilization of mineral resources, high grade iron ore resources will be exhausted gradually. Accompanying with the economic recovery iron ore prices after this fall is bound to return to its value to maintain a high level.The development and utilization of resources is gradually turning to the low grade iron ore. Restricted by technical development level and disadvantages of lean iron ore resources, the cost of utilization lean iron ore resources is relatively high. Making full use of their rich lean ore resources has become many countries' important strategy to get rid of dependence on foreign countries' ore. Over the years with the development and progress of lean magnetite mineral processing technology in China, the production number of concentrator has been greatly improved.As the world's largest steel producer and consumer countries, ensuring a stable and continuous supply of iron ore is particularly important for the healthy development of China's iron and steel industry. Chinese iron ore production and import data in recent years are showed in Table 1.With the expansion of iron and steel production, iron ore demand has also been a phenomenal growth. Taking 2013 for example, China's crude steel production is about 780 million tons in 2013, accounting for about half of the world's total output of crude steel. At the same time, China is also the first major iron ore import countries whose iron ore imports in 2013 was about 820 million tons, an increase of about 10%. The degree of external dependence is very high. In some years, the cost of China's iron ore imports was even more than $100 billion, and second only to oil’s import cost in all bulk commodities."

Jan 1, 2016

By K. Kryst, K. Elkayar

The increasing need to process lower grade contaminated copper concentrates and simultaneously produce higher purity copper cathodes necessitates a more diligent control in the electrorefining process. Ion exchange processes can be a powerful tool in controlling electrolyte impurities to ensure trouble free operation within the tankhouse and to help maintain cathode purity. In addition, some impurities can be recovered as a value added product. The use of a short bed ion exchange process provides a unique opportunity for impurity management in copper refineries. Several metals are discussed in this paper, including Sb, Bi, As and Ni and their methods of control and recovery within the copper electrolyte circuit. INTRODUCTION To produce a high purity copper product by electro-refining a copper electrolyte, it is important to control the concentration of impurities such as arsenic (As), bismuth (Bi), antimony (Sb), and nickel (Ni). These impurities are introduced into the electrolyte from the copper anode and can affect the copper product and the production operation. The presence of As in the copper product results in a lower electric conductivity and reduced workability of the copper. High levels of Bi in the electrolyte will result in a copper cathode product containing Bi. High Sb concentration will cause undesired floating slimes. A variety of methods have been developed to control the level of these impurities in the copper electrolyte including precipitation, liquid extraction, and ion exchange. These impurities can be recovered and used. This paper discusses novel methods that utilize short bed ion exchange technology to control these impurities. Also, the use of ion exchange to recover acid from the liberator cells bleed for reuse in the tankhouse is reviewed. SHORT BED ION EXCHANGE Short bed ion exchange technology has been employed extensively in the metal finishing industries for over forty years. Unlike conventional ion exchange, short beds are fixed beds without freeboard space. The application of short bed technology results in significant benefits when compared to conventional ion exchange. The resin used in this technology has a significantly smaller diameter than conventional ion exchange resin. As a result of the smaller resin size, exchange kinetics improves dramatically. This facilitates operation at higher flow rates and the use of smaller beds with a small mass transfer zone length. Smaller beds are especially important for applications that use chelating resins due to the high cost of the resin.

Jan 1, 2019

By D. D. Downing

This paper is a review of material selection considerations concerning protective coatings in the mining industry. The discussion will cover both capital-dollar projects and maintenance requirements. Emphasis will be on industrial finishes for structural steel and process equipment subjected to aggressive atmospheres. The presentation will cover the total needs of a job, emphasizing not only the owner's requirement for a cost-effective system during plant operations, but also taking into consideration the short-term requirements of general contractors, steel fabricators, erection firms and paint contractors.

Jan 1, 1979

By W. I. van Drunick

The Anglogold Ashanti (AGA) Navachab single stage SAG mill has provided an excellent setting for incremental optimization. Over the past decades, several interventions have resulted in marked improvements in specific performance; including steel ball scat removal, re-design of the mill lifters, replacement the pebble crusher and cyclone cluster, as well as the use of a vibrating screen in place of a discharge trommel. Recent initiatives now include an operating fine DMS circuit, studies on pre-crushing of the ROM feed and also fine-screening as an alternative to hydrocyclone classification. The current optimized state of the Navachab mill allows it to operate at approximately 20% higher efficiency when compared to mills of similar shell dimensions in gold mining, treating similar ore. This paper describes the systematic improvement of the SAG circuit to its current state.

Jan 1, 2012

By C. G. Williams

This paper describes the planning, development and operation of the Highvale Mine to supply coal to both the existing Sundance and the approved Keephills thermal power plants of Calgary Power Ltd. Reference is also made to the company 's Whitewood Mine, which feeds the Wabamun thermal plant .

Jan 1, 1979

By Roger Francis

There is increasing use of acid leach extraction methods at elevated temperatures and pressures by the mining industry. In many locations there are limited supplies of fresh water, and waters with higher chloride contents must be used, making conditions more corrosive. The fluids downstream of the main autoclave are hot, acidic, oxidizing and contain chlorides and present a challenge to the mining community to ensure reliable operation. Zeron 100 is a high strength superduplex stainless stee, that offers high corrosion resistance at a cost effective price. The paper presents a combination of laboratory data and service experience, particularly in the aggressive fluids found in downstream processing.

Jan 1, 2010

By R. Edinger

Aerospace and space products depend, probably more than any other products in industry, on advanced materials. While there are many ways of producing aerospace parts, in many cases the process does not allow the design of the metallurgical properties according to the part or product requirements in accordance with its mechanical configuration. Key to the next level of innovative manufacturing is the capability to control the amount of energy applied to the process, as well as the addition of materials in form of vapor or solid particles such as powder in order to build up the metallurgical composition required. With the development of a high speed pulsed laser-electron beam source, the LASTRON(TM) technology, we deliver the basic requirement for a digital manufacturing process of aerospace and space products. This technology, combining Laser and electron beam, finds application in welding, drilling-machining, and is currently modified to allow digital coating (PEB-PVD) methods. In addition to the coating, a powder metallurgical process, called Rapid Manufacturing (RM), will allow the precision melting of parts based on CAD/CAM files. The RM process and the digital coating will allow the production of graded aerospace alloys in parts for jet engines and aero-structures.

Jan 1, 2006

By DON E. MacDONALD

Marl in Alberta is confined to highly specific geological, hydrogeologica/ and climatic settings. Tufa is fa irly abundant in those areas of western Alberta where bedrock is of the Paskapoo Formation. Marl and tufa originate when the following conditions are met: presence of a carbonate source in drift or nearsurface bedrock; leaching of the carbonate by percolating groundwater; transportation of calcium and bicarbonate ions in a permeable aquifer; discharge at the surface as springs, seeps or lakes; re-precipitation of calcium carbonate. Alberta has seven categories of marl and tufa deposits, based upon over-all depositional environment and calcium carbonate

Jan 1, 1984

By L. Li

To accommodate the large payloads and harsh operating conditions associated with heavy vehicles in the mining industry, off-the-road (OTR) tires are typically used with heavy mining vehicles. These tires have increased abrasion and wear resistance due to their thicker tread, sidewall and bead thicknesses. Given these features, OTR tires are much stiffer than conventional passenger vehicle tires and cannot be mounted to a single-piece rim without damaging the structural integrity of the tire during the mounting process. Therefore, multi-piece wheels are used with OTR tires to facilitate mounting. While these assemblies are necessary, several instances of their failure have been reported to result in injuries or fatalities within the mining workplace. Many of these failures were specifically reported to be caused by the disengagement of the wheel lock ring - a component used to securely engage the assembly during operation. In this study, a threaded-connection locking mechanism has been proposed in place of the traditional lock ring design. The performance of this threaded-connection was numerically evaluated in a pull-out test against a conventional five-piece wheel assembly. The pull-out test was devised as a means of quantifying the engagement ability of each wheel?s locking mechanism. A high degree of modelling accuracy was maintained throughout the analysis by validating the vertical and horizontal static loaddeflection behaviour of the rim model of the five-piece wheel assembly against experimental data. Through validation, the model data were found to be within 10.5 and 4.80 %, for vertical and lateral loaddeflection behaviour, respectively. Results from the pull-out analysis found that the threaded-connection demonstrated a 113 % increase in the force required for disengagement to occur relative to the conventional five-piece design - a force of 9,550 kN in total.

Aug 1, 2013

By T. Loos

The Norddeutsche Affinerie operates an Outokumpu-Flash-Furnace as a smelting unit. The pyrometallurgical slag cleaning process is based on the slag reduction and settling in the electric furnace. Since 1972 when the slag cleaning furnace was built the throughput could be increased fourfold. However, an extensive optimisation effort is required in order to keep the copper loss low. A parameter study with a neuronal network model based on real process data was conducted to identify parameters impacting on the copper loss in the slag. It could be demonstrated that the main parameters responsible for copper loss in the final slag are fixed parameters of the flash furnace. For a better understanding of the copper loss in the electric furnace microscopic analyses of the slag structure and viscosity measurements were performed. Based on these results the reduction and settling of the copper containing droplets could be increased in both pilot plant studies and industrial scale. 4

Jan 1, 2007

By T. H. Wilson

In 1901, the Crow's Nest Pass Coal Company, Limited, began producing industrial coke in 212 beehive ovens at Michel colliery. By 1908, 486 ovens had been installed and in that year 147,623 tons of coke were produced. Coke manufacture has been continuous from 1901 until the present time (1946), with total production of 2,795,402 tons. At present writing, only 100 beehive ovens are operating and production is reduced to 1,800 tons per month, due to the shortage of suitable labour. These ovens are drawn by hand, on contract, and the workmen are exposed to considerable heat. A man draws three ovens in eight hours, thereby producing approximately 1072 tons of coke per day. In addition to the inefficient and costly method of drawing coke in beehive ovens, tremendous losses are experienced in the wastage of gas and tar, which are driven off into the atmosphere. Also, the yield of coke per ton of coal fed to the ovens is low as part 9f the carbon is utilized in producing heat to carbonize the remainder of the coal. A recovery of only 55 per cent of the carbon, as coke, is obtained. The coking process takes place from the top of the charge, which is 21/2 feet deep, downward to the floor. Six and a half tons of coal are charged and 3.6 tons of coke are drawn from the oven after 72 hours' carbonization. The beehive ovens using Michel coal produce a very hard and tough coke, large in size and of silvery appearance, which has served the requirements of both foundry and smelter for many years. In 1938, the Company made a careful study of coking processes with a view to introducing a more economical method than beehive ovens and one that would be less dependent on skilled labour, the supply of which was rapidly diminishing at that time. Various methods of by-product coking were investigated, and it was decided that the Curran-Knowles process offered the greatest possibilities because of the low capital investment in relation to output and also because the horizontal oven design was suitable for an expanding coal. Consequently, a test on Michel B seam coal, supervised by Mr. E. Burrough, of the Fuel Research Department, Ottawa, was run in the Curran-Knowles plant at West Frankfurt, III. The results of this test led to the construction of a ten-oven battery of 32 ft. 6 in. by 8 ft. 3 in. Curran-Knowles ovens at Michel, which were completed in November, 1939. This battery was built as an experimental unit, with provision for an additional ten ovens if the coke proved satisfactory for the market. In 1942, an expanding coke market led to the construction of a second battery of ten ovens, which were completed in April, 1943.

Jan 1, 1947