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By Frank Mucciardi, Zhongsen Yuan

A new heat transfer technology --- termed Thermopump technology has been developed. This technology originates from conventional heat pipe configurations but has now evolved into its own class of heat transfer units, which we refer to as `Thermopumps (TP)'. A key feature is that Thermopump technology can be applied to high temperature / high heat flux environments where conventional heat pipe technology fails. Moreover, when implemented in less demanding applications where heat pipes appear to operate, Thermopump units have been found to function more smoothly and reliably. This paper will introduce Thermopump technology and several applications of this technology in steelmaking and refining will also be discussed. In addition, this paper will focus on three classes of applications: 1) waterless, non-consumable, high efficiency Thermopump oxygen lance and/or burner for EAF's, 2) Thermopump ladle lance for the desulfurization process, and 3) Thermopump cooling panels for furnace walls and roofs. Facilities equipped with Thermopump technology are expected to he better than the current corresponding ones in terms of increasing productivity and energy efficiency while at the same time lowering operating costs.

Jan 1, 2004

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 J. van Deventer

Volatile gold prices in the face of rising costs for mining and refining is causing the mines to look for new ways to reduce costs and increase recoveries. This task is complicated by the fact that the gold in hereto unexploited reserves is associated with increasingly complex ores - either preg-robbing, refractory, associated with high concentrations of copper, or all of the above. Ion exchange resins can play a significant role in this quest for improvement. Although ion exchange resins have been used in Former Soviet Union (FSU) countries for the recovery of gold for many decades, it is still not widely used in the Western World. Synthetically manufactured ion exchange resins can be tailor-made to suit the chemical and mechanical characteristics of a specific application. As such, ion exchange resins can be used in a variety of solution matrices (e.g. cyanide, thiosulphate and acid), and process designs (recovery from clear liquor after solid-liquid separation or directly from the leached pulp). In this paper, a number of applications are discussed along with a review of recent developments in ion exchange technology.

Jan 1, 2014

By Hermann A. Derbuch

Twin Mining made a conscious decision when it changed from gold mine explorer and developer to become a diamond explorer in Canada?s Arctic. It was a decision of survival in an environment that saw junior gold companies either disappear or turn into dot com companies. Twin Mining learned fast and staked within weeks of that decision the first 50 sq. km of claims on, what became, its TORNGAT property at 59½° latitude on the east coast of the Ungava Bay in northern Quebec. This land position, 724 diamonds later (including 322 macro diamonds of gem quality, white and transparent) grew to 507 sq. km today. The 74° latitude called when Twin Mining exercised the option to acquire 3 claims owned by Helix Resources Inc. which revealed exceptional diamond potential. A gem quality 5.4 mm (0.768 carat white and transparent) diamond and the discovery of 16 pipes on 15.2 ha convinced Twin Mining?s board to sanction the deal. Both properties have outstanding features. Kimberlite Dykes and Pipes are in outcrop. The property locations have deep-sea access near existing infrastructure. Their locations are in an environment that is stable and development friendly and has a positive track record with successfully operating mines near-by.

May 1, 2001

By N. Shi, T. G. Joseph

ABSTRACT One-twentieth-scale field trials for conventional and concept dipper designs were compared to mid- and ultra-class-sized conventional dipper performance. Digging effort was used as the performance indicator for comparison. It was shown that linear relationships exist between dipper capacity, suspended hoist load, and peak hoist load. A ratio of conventional and concept dipper performance at the 1/20th scale was then evaluated to allow prediction of the performance of an ultra-class concept design using an independent ultra-class conventional dipper dataset. The outcome indicated a peak hoist requirement of 15.5% less to achieve the same production as the conventional design.

Jan 1, 2011

By Mi, Dong Liang, Jingyuan Bai, Victor Zhou, Xujun

Squirrel cage induction motors are the mostly used motors at present. Currently, the rotors of the squirrel cage induction motors are produced by aluminum die casting technique with the advantages of low cost of rotors. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size. Considering the huge quantity of motors, the die casting process is the best solution to produce copper rotor with economic cost. Because of the characteristics of copper, it is difficult to produce copper rotors by casting similar to that done in aluminum rotors. In order to improve the die casting quality of copper rotor, a new tooling structure was developed and the casting process of copper rotor was simulated and analyzed by Any-casting software. The filling process, solidification process, inner gas distribution and residual melt modulus were analyzed. It was found that the design of symmetrical runner and inner runner on both sides was helpful to reduce the impact of molten copper to the cavity surface during the filling process. The use of Slag traps array can reduce die casting defects inside the end rings. That will be helpful to improve the rotor quality. INTRODUCTION Squirrel-cage AC induction motors are most widely used in the world. In 2017, the total installed capacity of AC motors in China has reached more than 1.2 billion kW, and the annual power consumption accounts for about 60% of the total national electricity consumption. To improve the efficiency of squirrel-cage motor will be helpful to energy conservation and environment protection. There are several ways to improve efficiency of induction motors, using copper rotor is one of the most effective solutions. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size.

Jan 1, 2019

By L. Rao, P. Carabin

"Advances in thermal plasma torches have resulted in this technology becoming a commercially viable solution for chemical and metallurgical processes. The main advantages of plasma are its ability to control process chemistry and to build small footprint reactors due to its high energy density and reactivity of the free radicals that are produced. This paper focuses on thermal plasmas produced by DC torches and their applications for waste treatment, production of high purity metals, and nanomaterials. Both transferred and non-transferred torches have been used as either a source of heat or as a reagent in various industrial processes. INTRODUCTIONPlasma technology has become an ideal solution for many industrial chemical, metallurgical and mechanical processes (Venkataramani, 2002). Thermal plasma powered systems are typical used for their unique characteristics such as high energy densities, high temperatures, small installation sizes, rapid startup and shutdown features, controlled process chemistry and use of electrical energy as a heating source resulting in decoupling the heat source from the oxygen flow rate (Heberlein et al., 2007). Depending on the nature of the main plasma forming gas used, thermal plasma systems offer a high temperature heating source coupled with a highly reactive plasma plume rich in free radicals and ions which promote otherwise hard to drive chemical reactions, as well as high heat transfer rates.Industrial plasmas can be broadly classified as thermal plasmas and non thermal plasmas. Thermal plasmas are atmospheric pressure plasmas characterized by local thermodynamic equilibrium (Boulos et al., 1994). Thermal plasmas are typically established between any two current conducting electrodes separated by an insulator. A plasma forming gas is blown between the two conducting electrodes resulting in a high temperature plasma plume. A plasma torch generates and maintains an electrically conducting gas column between the two electrodes; a cathode (negative electrode) and an anode (positive electrode) (Camacho, 1988). If both electrodes are housed in a single housing, resulting in an arc enclosed inside the plasma torch, then such plasma generating torches are termed as non-transferred (NT) plasma torches, whereas, if the second electrode is external to the torch, creating an arc transferred between the cathode and the working piece, then such plasma torches are termed as transferred (T) plasma torches. Depending on the source of the electricity which can be either direct current (DC), alternating current (AC) at main network frequency or at radio frequency (RF), the plasma torches are classified as DC, AC or RF plasma torches (Venkataramani, 2002)."

Jan 1, 2012

By J. Donnelly, A. V. Deev

Substitution of coal and coke by renewable carbon (charcoal) is a low-risk and low-capital path to 50% or more reduction in net CO2 emissions by the steel industry. However, the high cost of charcoal and its low availability in most countries are barriers for the implementation of this approach. Development of an efficient wood carbonisation technology (slow pyrolysis) capable of producing large-volumes of charcoal from low-cost wood feed (e.g. wood wastes or forest residues) is an essential step towards the use of renewable carbon by the iron and steel industry. This paper provides a summary of the progress made over several years of R&D covering: (1) development and piloting of a new energy efficient slow pyrolysis process for production of charcoal from woody biomass at a competitive cost to the PCI coal, (2) techno-economic evaluation of the process. The main feature of the process is that the material undergoing pyrolysis is heated spontaneously without the supply of heat or air to the reactor. This makes it possible to carbonize large volumes of small-sized wood (e.g. wastes and residues) in a single reactor unit and capture high calorific value pyrolysis by-products

Jan 1, 2015

By Robin Belley

Outline Introduction Wabush Mines HistoricalBackground Mine and Concentrator at WabushMines High Intensity Magnetic Separators (HIMS) Development of the Manganese Removal Process Pilot Plant Testing Phase Manganese Removal Line 1 Coming Phase: Manganese Removal Line 2 Manganese Concentration Process Development Historical Background 1847: Creation of the Cleveland Iron Company1850: Opening of its first iron ore mine in the Upper Peninsula of Michigan 1965: Beginning of Wabush Mines at Scully Mines, Wabush, Labrador. 1980-1990: Questions raised about how to exploit Scully high Mn Ore (> 2%)Part of the available ore is not saleable due to too high a level of pyrolusite (MnO2) Adding this ore to the resources would be valuable (longer mine life and lower stripping ratio) 1990s: Testwork for Manganese removal Many different processes are studied over more than a decade High Intensity Magnetic Separators (HIMS) are identified as the best technology for Mn removal 2007: Pilot Mn removal line installed Testing carried out through 2007-2008 First Production Line is ordered (2008) 2009: Cleveland Cliffs (now Cliffs Natural Resources)acquire the remaining part of Wabush Mines 2010: Mn Removal Line 1 construction & commissioning Summer 2011: Mn Line 2 Construction

May 1, 2011

By J. Kolacz

"A new sensor based sorting system has been developed, providing a possibility for laboratory scale testing and further scale-up of the separation results to the industrial operation. The new system contains different sensors as: X-ray detectors, visible light cameras, NIR cameras, ultraviolet cameras and magnetic sensors, in the same sorting unit. The sorting unit allows advanced calibration options and fine-tuning of the installed sensors to achieve the best separation effect under controlled conditions. Finally, the processed material can be analysed and separated by the rejection mechanism, similarly to the industrial scale operation. At the same time, the process is carried out with limited amount of material allowing detailed statistical calculations for processed particles and all sensor types. The optimal settings and sensor types are specified for the industrial application.The paper describes the scale up of the results achieved for iron ore and coal, where the test work was first carried out using the new laboratory sorting system and where the industrial scale sorting system has been built, in the final stage. The industrial scale sorting results showed a very good correlation between the laboratory and full scale operation. Thanks to the detailed study carried out in the laboratory equipment, the settings of the sensors in the full scale operation provided much better separation efficiency. It was especially important to provide proper setting for the X-ray sensor data calculations, which can be very critical for achieving the best results. During the industrial scale sorting of coal, the input material had 40-55% rock particles as the direct source of ash in the coal stream. The optimal laboratory unit settings and transferring these settings to the industrial sorter, provided 98.8% efficiency for removing rock particles with only few % losses of coal."

Jan 1, 2016

By M. Behrouz

Thermal power plants convert thermal energy due to nuclear reactions or the combustion of coal, gas, heavy oil, or some other hydrocarbon to electrical energy. They consist of a variety of equipment, such as boilers, turbines, generators, cooling towers, and auxiliary equipment. Any factor that affects the equipment efficiency affects the overall efficiency. Analysis of the cooling tower and raw water using the Langlier Saturation and Ryznar Stability Indices showed that the cooling water at Sarchesmeh was slightly scaling with respect to silica. Cold lime softening was found to be a cost-effective method to produce cooling water with adequate properties to reduce the cooling water make up from 85 to 70 m3/h and blow down rate from 35 to 20 m3/h.

Jan 1, 2007

By Patrick Mclaren, Peter B. Hale

Canada, with one of the largest continental shelf areas in the world, has done little to evaluate its offshore unconsolidated mineral resources which include heavy minerals (gold, chromite, rutile etc.) and industrial minerals (silica sand and aggregates). During glaciation much of the continental shelf was covered with an ice sheet and later subaerially exposed with the result that glacial, glaciomarine and fluvial processes deposited sediments that may contain heavy minerals derived from onland locations. With rising sea-levels, beach and nearshore processes may have served to concentrate heavy minerals by winnowing and removing the lighter mineral components. These potentially valuable resources can be found with suitable exploration techniques such as seismic profiling and bottom sampling. Gold deposits are known to exist off the coast of Nova Scotia, and on the basis of form er beach mining, gold deposits probably occur off Vancouver Island and the Queen Charlotte Islands. Large deposits of silica sand occur near the Madeleine Islands and it appears likely that supplies of marine aggregates are present close to urban markets or sites of future mega-projects such as oil field developments. This paper, which is based upon a review of literature and consultation with members of the Department of Energy, Mines and Resources' Coordinating Committee on Ocean Mining (DCOM), is the first step in assessing the Canadian offshore f or its resource potential with respect to quantified deposits, known and speculative mineral occurrences. Although this is a subjective evaluation, the potential appears promising. A more detailed resource inventory is required to provide a more certain assessment.

Jan 1, 1984

By D. Royston

In SAG mills fed with a variety of ore types, hard packing between the shell lifters can come and go depending on rock type and rock size distribution and the presence of a binder. Packing can appear in all sizes of SAG mills, and can be tenacious. High ball impact forces (depending on ball size) in larger mills may compact and encourage packing. Packing can have a negative impact on milling performance and a change in shell liner design may be required to remove it. However shell liner design changes need to be managed with care to ensure liner reliability. In smaller mills control of packing can extend shell plate wear-life and may help to maintain milling performance in fixed-speed mills through the liner wear-cycle.

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 M. A. Hararah, T. Neesse, M. G. Farghaly, G. Proellss, P. Kaniut, W. Rubarth

ABSTRACT: This paper presents two new options for hydrocyclone control. Volume split control using a control valve in the overflow is applied for the stabilization of separation results at changing feed conditions. Controlled water injection to the conical part of the cyclone leads to the reduction of fine particles in the underflow. Hydrocyclone monitoring in both cases is performed by optical sensors that indicate the spray angle of the underflow. Applications in mineral processing for desliming, classification in closed-circuit grinding, and dewatering are demonstrated.

Jan 1, 2011

By Gurupraveen Ramanathan

Slot raises are relief holes within a stope in longhole stoping methods, designed to provide a free face that facilitates the expansion of the blasted rock during blasting, ultimately achieving the desired fragmentation. Various methods are employed to produce these slot raises, like conventional drop raise drilling, raisebore & V30 drilling. However, slot drilling is generally characterized by high costs and limitations in precision, resulting in unplanned ore losses and dilution. This paper introduces a novel alternative to slot drilling referred to as the "paste slot", designed specifically for paste backfill operations in underground mining. This new method emphasizes considerations in cured paste strength, paste wall removal, and stope dimensions and employs modified drop raises or dumped rings to optimize blast gas effectiveness and material flow. The paste slot method eliminates the need for reamers and reduces the total slot drill meters an average from 650m to only 300m for narrow stopes (3-4m wide). This significantly reduces the stope cycle time, leading to substantial cost savings and increased productivity. This new method was successfully implemented at the underground mines in Canada and Australia, resulting in a 20% reduction in stope cycle time and cost savings of 53,000 USD per slot compared to the conventional slot. This paper discusses the design and execution strategy of the paste slot method in underground paste backfill operations. It highlights the advantages of the method, shares operational insights gained during implementation, and showcases its potential applicability to other mines across Canada and globally.

Oct 1, 2024

By A. Galip Ulsoy

This review paper is intended to provide, the mineral process engineer with an introduction to the concepts, terminology and practice of mineral process control. It also provides an extensive sampling of the vast body of literature relevant to this topic. The topics discussed include the principles of automatic control, instrumentation, mineral processing unit operations, process modeling and simulation, and process and plant control.

Dec 1, 1981

By F. J. Alcock

The Appalachian region of Canada comprises the three maritime provinces; Nova Scotia; New Brunswick; and Prince Edward Island; and that; part of the Province of Quebec lying south and east of Logan's fault. This; major thrust runs in a gently curving line from lake Champlain to Quebec; city and thence down the valley of the St. Lawrence to pass between Anticosti; island and Gaspe peninsula. To the northwest lies the St. Lawrence; Lowland division of the Interior Plains geological province; a region underlain; largely by early Palxozoic strata; which for the most part lie horizontal; or with low dips; where faults occur they are predominantly of the normal; type; and only locally are the beds cut by intrusive rocks. To the southeast; on the other side of the fault zone; an entirely different set of conditions is; encountered. There; Lower Devonian and older strata stand at high angles; are sheared and thrust faulted; and are intruded in many places by granitic; igneous bodies. The present paper is designed to outline briefly the geological; and structural history of this geological province and to emphasize; the part that structural conditions have played in connection with mineral; deposition.

Jan 1, 1954

High Pressure Grinding Rolls (HPGR) are said to be a good option in new grinding circuits. Due to their low energy consumption compared to other grinding systems such as SAG milling, there is a strong incentive to check their behaviour for certain ore types. With rising energy prices the operation will become even more beneficial in future. As published in the past, the HPGR is claimed to increase the liberation of the valuable mineral component within an ore. An investigation at the research centre of Polysius was conducted to substantiate the liberation behaviour in finish grinding operations. A pilot scale HPGR test unit (POLYCOM MAGRO) with a roll diameter of 950 mm and processing capacity of 80 t/h was used. Grinding tests were completed with a screen and a two stage drying air separation process (SEPOL). Analysis included standard screen analysis, fractional XRF and modern MLA technology. A technique was developed to oppose the amount of produced slimes (resuming bad flotation) against the positive effect of producing high mass fraction at flotation-easy sizes. The paper shows how effective the use of a dry grinding separation could be in terms of production of mass of liberated metal.

Jan 1, 2012

By M. Somppi, D. Weirmeir, Z. Yamak

"Milling operations commonly employ activated carbon to capture complexed gold from lixiviants in leaching processes. As the carbon moves through pipes, pumps, vessels, kilns and other processes in the gold leaching circuit, this consumable may experience losses by various mechanisms like attrition, breakage, and rupturing. Whenever possible, capturing the fine gold-bearing carbon portion of this stream could provide value to milling operations at low capital cost and manageable financial risk. Identifying, testing, and validating the successful payback of a low-tech flocculant system is described. However, the work more closely explores a Monte Carlo risk-based methodology for understanding the potential payback of this project at various confidence levels – an approach that many improvement projects can follow where some level of uncertainty exists.INTRODUCTION Gold milling operations commonly employ activated carbon to adsorb gold from solutions. Normal handling causes the carbon particles from this material to abrade, break, rupture to a size that becomes too small for further use in the process. Operations often concentrate on capturing the fine particles because gold is associated with the carbon and this metal content can be a valuable revenue stream for toll processing. However, the small particle sizes become difficult to separate from the process and can ultimately leave the facility in the waste stream. Hence, operations often place a great deal of care in capturing as much fine carbon as possible by a variety of methods including using screens, settling tanks, and chemical methods. Retrofitting a circuit to capture more carbon fines is common but can expose the operation to financial risk. Approaching this potential improvement by leveraging a Monte Carlo methodology can be effective in understanding the risk and the associated payback of a project at various confidence levels. This method provides a strong framework for capital go-no-go decisions and the structure to validate the potential project success before implementation."

Jan 1, 2019