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By F. Awotwe-Appiah, P. Koshy, J. Dankwah, J. R. Dankwah

This research investigates the generation of an effective carbonaceous material from waste ‘pure water sachets’ and their subsequent utilisation as reductants for the reduction of the Opon Mansi iron ore. Composite pellets of Opon Mansi iron ore and pulverised carbonaceous material generated from waste pure water sachets were heated from room temperature to 1200 °C in a gas fired furnace for seventy minutes. The reduced pellet was analysed chemically for its oxygen and carbon content using a LECO Oxygen/Nitrogen and LECO Carbon/Sulphur analysers, respectively. It was observed that nuggets of metallic iron were readily produced with the carbonaceous materials acting as an effective reductant and source of chemical energy. XRD analysis of waste ‘pure water sachets’ revealed that the polymer was semi-crystalline with peaks that were identical to those of high density polyethylene (HDPE). Gas emission behaviour of the iron ore-PWS pellet was studied in a horizontal tube furnace at 1200 °C using an infrared gas analyser; the results revealed an exhaust gas rich in the reducing gases CO and CH4 along with CO2.

Jan 1, 2015

By G. M. Ritcey, V. M. McNamara

"In the processing of gold ores by the cyanidation route, effluents which are discharged to the tailings areas can contain up to several hundred parts per million of cyanide in complex combination with similar quantities of heavy metals. Complicating this obvious problem of waste control are concentrations of thiosalts and thiocyanates which are roughly equivalent to the amounts of cyanide species. Although most gold mills are located in thinly populated areas, such contaminants can represent a potential environmental problem due to the various limitations exhibited by on-property ponding.The former Extraction Metallurgy Division of CANMET recognized the problem and, in early 1974, invited representatives of the gold mills to Ottawa to discuss the situation. At that meeting members of the Division presented a ""state of the art"" literature survey of cyanide abatement technology for waste solutions, together with preliminary cost estimate data(1). Shortly thereafter, Environment Canada, together with Environment Ontario, decided upon a guideline of 0.1 ppm (0.1 mg/l) total cyanide content as tolerable for an effluent stream which is discharged, in any manner, to the watershed."

Jan 1, 1978

By G. C. Weatherly, D. S. Wilkinson, A. M. Limarga

In addition to the harsh environment, materials for high-temperature applications are often subjected to a significant mechanical loading. Several researchers have noted that the rate of oxidation can be affected by stress in a range of materials. We have recently studied this effect in y-TiAl, based on the preliminary work of Magnan and Weatherly which showed that nitridation rates on the tensile side of a flexural creep specimen could be 10 times higher than on the compressive side. We have since developed a four-point bending creep setup capable of controlled atmosphere testing. We present quantitative data on the effect of creep on scale growth under a range of atmospheric conditions. Finite element analysis will also be used to show how modest applied stresses can have a large effect on scale growth rates through the generation of large stresses due to the mismatch of creep rate between the metallic substrate and the scale.

Jan 1, 2004

By C. Okay Aksoy

In Turkey, the increasing demand for lignite has necessitated an increased emphasis on both lignite production and recovery. This emphasis has resulted in a gradual increase in the application of the retreat longwall mining method for both its product recovery and productivity benefits. Also, in order to maximize the recovery of the natural resources and to increase total production, it is necessary to take advantage of underground reserve before abandoning the mine. This means that at the end of the life of the mine, the main drift safety pillar and the shaft pillar will generally be extracted. This investigation a preliminary study of the stability of the main drift and the shaft at the Hustas Mine as the safety pillars are extracted. In this study, field surveys belonging to the underground colliery of Hustas Co. in Soma have been investigated with the help of LAMODEL working under the Laminated Displacement Discontinuity principle for the models calibrated as a results of physical model and finite element analyses. The convenience of Laminated Displacement Discontinuity Analysis has been researched in such studies. The results out of the models have been coherent with the previous studies.

May 1, 2004

By X. X. Wu, Q. Zhang, R. H. Fan, Y. J. Feng, J. D. Liu, P. Z. Zhao

In the present study, AA6016 automotive sheets with different grain size were fabricated through changing fabricating parameters, and the effects of grain size on the bendability were studied by bending test and optical microscopy. The results showed that the sheet with coarse grains exhibited poor bendability, and some micro-cracks were revealed at the surface of the bending samples. While the sheet with fine grains exhibited good bendability, and the bending samples showed smooth surface. Shear bands on the cross section of bending samples were observed. It was found that samples with coarse grains had more shear bands. These shear bands distributed in bundles, which facilitated the formation of continuous neckings and micro-cracks. However samples with fine grains had less shear bands, which distributed uniformly. The decrease of grain size could not only hinder the formation of shear bands, but also improve the homogeneity of its distribution during bending. On the other hand, refining grains could increase the amount of grain boundaries, which impede the propagation of shear bands. Hence the decrease of grain size could hinder the formation of continuous neckings and micro-cracks during bending, resulting in the significant improvement of the bendability.

Jan 1, 2015

By J. Pepin

When using alternating current submerged arc welding (SAW) to produce pipes from microalloyed linepipe steels, it is critical to balance penetration depth and deposition rates, in order to minimize the number of weld passes while still maintaining good heat affected zone (HAZ) microstructures and properties. A series of bead-on-plate (BOP) submerged arc welds were performed on X70 steel, using different waveform variable settings (i.e., balance, offset and frequency). Weld bead cross-section profile deposition and penetration areas were measured, and both Vickers hardness and Charpy V-notch impact testing were performed. Both single electrode and tandem electrode welds were evaluated.

Jan 1, 2011

By Y. Miyabayashi, K. Nishikawa, H. Nagai

JX Nippon Mining & Metals Group recovers valuable metals from end-of-life electronic products in an economical and environmentally-benign way, based on technologies that have been acquired in mining, smelting, and refining operations over time. End-of-life electronic products contain halogens and hydrocarbons. When such materials are treated in the copper smelting process, corrosion of equipment and discoloration of sulfuric acid occur. As a countermeasure to these problems, we have developed pretreatment processes that include an incinerator, exhaust gas washing towers, and a defluorination facility. By implementing these improvements, we have been able to treat a large volume of end-of-life electronic products efficiently in the copper smelting process.

Jan 1, 2014

By Kevin Ross

Feasibility Study Team Processing / Engineering?Hatch, Vancouver Mining / Reserves?Australian Mine Consultants, Brisbane Geology / Resources?Roscoe Postle Associates, Vancouver Environmental / Permitting?Rescan, Vancouver Tailings BGC, Kamloops Probable Mine Components Mining tending towards caving methods Underground mine accessed by shaft /conveyor & decline Processing plant producing copper concentrate containing gold Concentrate trucked to rail head for export Non saturated tailings disposal

May 1, 2006

By Jianzhong Liu

Based on the characteristics of overburden rock strata movement, surface ground subsidence and casing deformation and failure, a tension-shear combination failure model of surface borehole was set up. The main controlling factors of the mining-induced deformation and failure of surface borehole were researched with this failure model and the limit analysis method. The mining methods and geology conditions mechanics action mechanism to surface borehole and its time ?space evaluation rule was found. The surface borehole deformation and fracture rule were advanced. It provides theoretical support to optimizing layout, structure type, security measure and local casing protection of surface borehole.

Aug 1, 2013

By Richard P. Reiff

"The Facility for Accelerated Service Testing (FAST) program has been involved in numerous rail wear tests since its inception in 1976. A number of specialized tools have been developed to aid in assessing specific performance parameters including gauge face wear, head height loss, metal flow, head area loss, hardness, and welded rail end batter. The layout of a test site, including position in curve, number of measurements per rail, and train operation must be properly controlled/monitored to provide valid wear comparisons.This paper will provide an overview of the above-mentioned tools and techniques. In addition, a summary of recent test results from FAST, including information on head hardened rail investigations, will be provided. A set of guidelines for establishing a revenue service field test site will also be provided to aid users in performing evaluations of their own.IntroductionBackground of Rail Wear Testing at FASTThe Facility for Accelerated Service Testing (FAST) located at the Transportation Test Center, (TIC), Pueblo, Colorado has been involved with testing of rail since program initiation in 1976. A huge data base of rail wear information has been gathered from FAST operations under a variety of rail metallurgies, lubrication conditions, and measurement techniques. Attempts at obtaining meaningful rail wear information from early (1976-1978) FAST rail wear data was hampered by two main factors: (I) measurement techniques were insufficiently accurate for the amounts of wear being experienced, and (2) the lubrication was not sufficiently controlled to obtain uniform conditions for a sufficient measurement time period.Subsequent test periods were operated with improved measurement techniques and controls that ensured statistically valid data. The policies and conditions that permit accurate rail wear assessment will be reviewed and outlined in this paper, along with some specific TIC and field examples that will allow the user to improve the accuracy of a field rail test on their own operating property."

Jan 1, 1988

By M. R. Coffin

In recent years, improved operation of the Kidd smelter has resulted in an increase in blister production capacity. Due to manpower and equipment limitations anode production and treatment rates could not be increased without incurring significant additional operating expenses. The option chosen to expand casting and refinery capacity to meet the available blister supply was to increase the anode thickness while maintaining the same anode exchange cycle in the refinery. This has resulted in a cathode production increase of almost 10% for minimal expenditure. Equipment and process modifications required to cast and refine the thicker anodes are discussed in this paper, along with the Six Sigma methodologies used to identify them. Key areas covered are Hazelett continuous caster operation, refining process parameters, plating performance and cathode quality.

Jan 1, 2007

By J. R. Pronovost, P. M. Tiley, D. W. Watts

"In 1980, J.S. Redpath Limited were retained by Dickenson Mines Limited to increase hoisting capacity from 700 to 1000 tons per day. The hoisting capacity of the present skip-over-cage system could not be increased significantly through design modifications. The other constraint was a minimum of disruption to the current production. The Dickenson shaft was a three-compartment shaft from surface to the 8th level and four compartments before the 8th to the 23rd level. The solution to the problem was to remove the services from the shaft man-way compartment from the 8th level to surf ace by drilling a borehole close to the shaft and rerouting those services through the borehole to the 8th level. A service compartment would then be available from surf ace to the 23rd level.By providing a service hoist in this compartment, the skip hoist would then be free to produce the 1000-tons/day required production. This paper will describe the search for the required hoist and the friction hoist selected for the project, and trace the design modifications required to modify the hoist to suit the Dickenson application and satisfy the Department of Labour safety requirements.The paper has been co-authored by J.S. Redpath Limited and C.L. Tiley Associates, who participated in the design changes and eventual commissioning of the hoist.IntroductionIn the earl y part of 1980, J.S. Redpath Limited conducted an engineering study on the Dickenson Mines Limited No. 1 Shaft materials handling system. The object of the engineering study was to investigate the possibility of increasing the tonnage hoisted from the No. 1 Shaft complex by adding a service cage compartment and service hoist. This would permit utilization of the existing hoisting plant solely for production hoi sting. A further consideration of the engineering study was that any alterations had to be accomplished with little, or no, interruption to production."

Jan 1, 1982

By F. Romero

In the last four years, Compañia Minera Doña Ines de Collahuasi has been working in the application of advanced multivariate statistical techniques for the improvement of the metallurgical processes. In this paper the main conclusions for the application of multivariable analysis to the EW process are presented; including the identification of (target) process patterns according to throughput and quality criteria. Based on the process patterns, process variables hierarchies were identified by selecting the most influential ones, as well as to identify and isolate the root causes of pattern deviations and sub-standard operating conditions, cause-effect relationships were established, leading to the definition of process policies and controls to give early corrections to potential failures. The analysis was focused on cathode quality, specifically in its sulfur content, using an empirical model based on those variables that from a phenomenological and statistical stand point appeared to be the most influencing ones.

Jan 1, 2007

By M. A. T. Cocquerel, M. G. Burcher, J. G. Eacott

"This paper is based on work carried out to examine the feasibility of increasing the smelting rate of two oil-fired calcine-charged reverberatory furnaces . Various constraints prevented physical enlargement of the furnaces and so allention turned to the use of preheated combustion air or oxygen enrichment to bring about the required increase in production. As a basis for further calculation, a furnace heat balance is determined using the smelting metallurgy and combustion data for the current operation. Various other operational data are tabulated and compared with similar data from other operating copper smelters.New heat balances are derived for various levels of combustion air preheat at the current smelting rate, and the effects of air preheat on oil consumption, combustion air and waste gas volumes are tabulated. These data are used to demonstrate the level of increased throughput which would be obtained before constraints in existing gas handling equipment are encountered.A similar exercise for oxygen enrichment is set out, with oil consumption, combustion air and waste gas volumes at various enrichment levels tabulated for the current smelting rate. These data are in turn used to demon strate the smelting rate which would be achieved at a practical level of enrichment before waste heat boiler and gas handling constraints are encountered.The energy implications for both cases are summarized."

Jan 1, 1980

By G. J. Desroches, E. Ozberk, M. J. Collins, B. D. Krysa, I. M. Masters

The zinc refinery of Hudson Bay Mining and Smelting Co., Ltd. went through a major modernization in 1993, when the roaster and the calcine and fume leach circuits were replaced by a new Sherritt zinc pressure leach plant. The HBMS plant, in Flin Ron, Manitoba, represents the first commercial application of the Sherritt two-stage zinc pressure leach process, with /00% of the zinc concentrate feed processed in autoclaves. The process design of the new plant required definition of the deportments of elements such as antimony, arsenic, chlorine, cobalt, fluorine, germanium, magnesium, manganese, selenium, tellurium and thallium. This paper describes the deportment of these elements in the commercial zinc plant during the first nine months of pressure leach operation, and compares these results with operations prior to the introduction of pressure leaching, and with the results of tests carried out in the She"itt laboratory during the process development phase.

Jan 1, 1995

By Eric D. Marks

Fatalities resulting from ground workers colliding with objects and construction equipment accounted for approximately 18% of the total construction fatalities experienced in 2010. Current injury and fatality measuring methods have proven to be inadequate due to their use of passive measures of safety rather than a more active approach, such as the use of leading indicator data (also called near misses) of hazardous proximity situations between ground workers and heavy equipment on construction sites. The objectives are to create and evaluate the effectiveness of a reliable algorithm for collecting and analyzing the resulting leading indicator data from hazardous proximity situations. Numerous experiments emulating typical interactions between workers-on-foot and heavy equipment are used to evaluate the proximity sensing and detection technology. Safety leading indicator data (also called near misses) generated by the proximity sensing and detection technology during the experimental trials are used to create and assess the resulting algorithm. Results from the experiments indicate that leading indicator data generated from these systems can be processed and analyzed to identify hazardous proximity situations and incidents on construction sites.

Aug 1, 2013

By M. Soleimanifar

With more and more industrial construction projects implementing RFID and other sensor-based technologies on fabrication and project sites, new innovative processes are needed to help automatically read and re-position RFID tags while reducing the cost to deploy RFID infrastructure over large areas. RFID tags are being used on construction sites to help identify the location of materials, equipment and personnel to aid in finding project critical materials and equipment required to construct the industrial facility on time and on budget. This research provides a cost-effective process for reading tens of thousands of RFID tags over large project sites from outdoor laydown yards, to warehouses to the workface where the materials and tagged equipment are installed. Based on the collected RFID and sensor data, localization mechanisms determine the most recent coordinates of the tagged components. The paper will cover analysis of RFID collected data and key lessons learned from a commercial deployment of the SiteSense® system with one Alberta-based industrial contractor, JV Driver Fabricators, at an 80-Acre module, pipe spool and structural steel fabrication site.

Aug 1, 2013

By M. Drozd, M. Somppi, Z. Yamak

"Granular activated carbon is widely used in the gold mining industry for gold extraction from aurocyanide-containing slurry. The extraction process can employ carbon as part of the gold recovery operation for various circuit designs including carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) circuits. However, various qualities of activated carbon exist and the durability of the material can change significantly from source to source. Handling this expensive reagent can pose challenges when fine carbon losses occur in the CIP, CIC, and CIL circuits. Additionally, any gold that is adsorbed to these carbon fines can also be lost by various mechanisms including carbon attrition and fracturing, inefficient coarse-fine separation, and poor carbon fines capture. With the above in mind, a series of tests were conducted to investigate standardizing simple laboratory methods for testing carbon quality. A standard procedure beyond or enhancing ASTM methods can serve as additional starting points for evaluating carbon specific to the gold industry. The investigation focused on size distribution, flatness, wet attrition resistance, surface area, gold kinetics, and gold loading. The final results provided information to generate an equation for ranking carbon samples to plant performance.IntroductionActivated carbon for use in gold extraction is amongst the most commonly found processes in modern gold-milling plants. Although gold losses are inevitable in the milling process, operators often focus on the importance of maximizing gold recovery. One focus area that is important in gold recovery is optimizing the use of activated carbon and examining potential changes to realize improved economics for carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes."

Jan 1, 2017

By Bruce Mennie

PT Freeport Indonesia (PTFI) operates copper and gold mining operations in a mountainous area of the Mimika regency, near Tembagapura, Papua (formerly, Irian Jaya), Indonesia. The mining and concentrating operations typically produce 240,000 metric tonnes per day of Copper and Gold ore from the combined mining of an 80,000 tonne per day (ore) block cave operation (DOZ Mine) and a 160,000 tonne per day (ore) open pit mining operation (Grasberg Open Pit). The Grasberg Open pit mine will be complete in 2016 at which time PTFI?s operations will convert to Underground. Mining operations will transition from today?s mixed surface and underground operation to full underground mining over the next 6 years. This paper reviews the history of Redpath?s relationship with PTFI, beginning with a raiseboring contract in 1981 and evolving into vertical and horizontal development contracts of up to 37,700 equivalent metres of lateral development and 4,000 metres of vertical development in 2011. An overview of the current operations (PTFI?s Grasberg Open Pit and DOZ Underground Mines) and transition period (challenges for the transition from current to future underground mines) is presented with details of development of common underground infrastructure and future mines; Big Gossan Mine, DMLZ Mine, Grasberg Block Cave Mine, and the Kucing Liar Mine.

Oct 1, 2010

By Bétournay. M. C.

Advantages ?Safety ?Health ?Rapid, continuous development, productivity ?Stope dilution reduction Disadvantages ?High cost and long time for equipment development ?Hard rock mining condition limitations ?Size of equipment ?Equipment set-up time, down time ?Performance does not meet financial return targets ?Drill and blast retains advantage in cost, productivity, capital investment, application flexibility ?Stress accumulation issues in deep mining, ground support and material handling issues in weaker rock

May 1, 2009