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Jan 1, 1994

By B. C. Slocombe

A large derelict inner city site was regenerated for use as a distribution warehouse. Difficult topography and soils conditions required the adoption of a combination of specialist geotechnical processes. Particular attention was paid to the preparation of the site, programming and capabilities of each technique as additional soils information became available.

Jan 1, 1989

By G. J. Ackland, K. Saksl, F. Brunke, M. Kohnke, B. Tegner, C. Siemers

The application of titanium alloys is limited to 550°C due to their poor oxidation resistance. It is known that the addition of niobium decelerates the oxidation of titanium alloys whereas elements like vanadium do not improve titanium’s oxidation resistance. The underlying mechanisms are not yet well understood. In the present study, different binary titanium-niobium and titanium-vanadium alloys as well as commercially pure titanium were investigated. Oxidation experiments were carried out at 800°C up to 288 hours followed by metallographic analyses to study the oxide layer morphology as well as the microstructure at the interface. Energy-dispersive X-ray spectroscopy mappings were used to identify possible changes in the distribution of the alloying elements. In addition, micro-focused hard X-ray experiments were performed to layer-wise analyse the phase composition in selected samples. As expected, the niobium containing alloys show a better oxidation performance compared to commercially pure titanium and the titanium-vanadium alloys. The oxide layer consisted of TiO2 and Ti2O3. Depending of the niobium content, a niobium-rich layer developed below the metal-oxide-interface minimising oxygen diffusion into the titanium matrix. Based on these results, the minimal niobium content needed for improved oxidation resistance was identified so that alloys of technical relevance can now be developed.

Jan 1, 2014

By D. Q. Cang, G. Duan, H. X. Li, H. Bai

"Life cycle assessment (LCA) is a valid environmental evaluation method and enterprise environmental management tool used in industrial ecology areas. In this paper LCA was newly used to evaluate the environmental impact of manufacturing of alumina by Bayer process in china from two aspects of logistics and energy flow, GaBi software acted as analysis tools with evaluation model established, and several environmental impact assessment criteria were selected based on the actually typical date of Bayer alumina producing process. Evaluation results show that alumina manufacturing by the Bayer process has a great impact on the global warming and human health of respiration, even roasting process gives rise to the greatest impact of winter fog index. Scenario analysis proposed ways of reducing environmental load caused by Bayer process including: (1) the economic and efficient use of mineral processing technology; (2) optimization of energy use, saving power consumption or the use of new more economical source of energy; (3) actively promote the use of innovated technology and equipment in alumina manufacturing and waste such as red mud utilization process.1 IntroductionSince 2002, China is already the world's biggest producer of aluminium, in 2007, China aluminum production has accounted for above 1/3 all over the world, 2009 for 13 million tons and to the end of 2010, China aluminum production is expected increased to be over 15 million ton [1,2,3]. While as the raw material for producing aluminum the alumina production in china has up to 19.46 million tons of the world's total quarter in 2007, by the end of 2009 China alumina production has achieve to 23.78 million tons [4,5]. China has rich bauxite resources with proven reserves about 23 million tons, but the great majority of china bauxite is hard monohydrate diaspore type with low ratio of aluminium silicon, high impurity content and poor aluminum dissolution performance, that cause high energy consumption, long and complex process, high production costs and heavy environment load[6,7]. Before most used alumina production was sintering process rather than Bayer method in china, over the past decade Bayer method has been widely applied instead of sintering process or combination both forming joint process, premise is improving bauxite quality by mineral processing or adding imported rich bauxite mineral[6,8]. In general each ton production of alumina needs bauxite 1.6~2.20t, limestone 0.7~1.7t, soda 0.250kg, fresh water 12.30 cubic meters, in addition to consume large amounts of energy, and emission waste water over 8.0 cubic meters, dust 2.3~5.7 kg, red mud 0.8-1.5 tons. In china Red mud yield nearly 30.0 million tons every year, accumulated stock is approximately 0.2 billion tons, by 2015 accumulative total red mud is expected to reach 0.35 billion tons [9-13].We know aluminium industry and alumina production have produced large waste, make large energy consumption and its environmental impact could not be ignored. Expecting to optimize production processes and achieve resource recycling for this industrial process the proper environmental assessment is very necessary. Currently Life Cycle Assessment (LCA) is generally recognized as the approved tool to achieve the purpose. The essence of LCA tool is to examine, identify and evaluate a kind of materials, product, process, or a system of environmental impact in their whole life cycle. The life cycle of materials or products includes whole process from raw materials obtained to the final disposal, or more ideal with original or other forms of the whole process of recycling [14-17]."

Jan 1, 2011

Copper Recovery from Printed Circuit Board by Carbonisation

Sep 13, 2010

By Sergio Neves Monteiro

In the present work, a ceramic foam elaborated with illitic clays was characterized. Properties related to density and compression strength were determined in samples fired at 1300oC, a temperature that permits the clay structure to generate and retain gases that will produce the foamy structure. The microstructure of the ceramic foam was studied by X-ray diffraction, scanning electron microscopy and mercury porosimetry. The results showed that the ceramic foam presents a bulk density of 0.38 g/cm3. The microstructure is formed by large open pores, quartz particles and vitreous phase.

Jan 1, 2006

By S. G. McAnally

This is one of a series of papers describing mining and crushing methods and costs at cement plant quarries throughout the United States and deals directly with the methods employed and costs obtained at the Reliance quarry of the Giant Portland Cement Co. at Egypt, Pa., although it is more or less descriptive of the methods used throughout the Lehigh Valley cement district. Systems of transportation vary according to local conditions, such as proximity to the mill, depth of quarry floor with relation to the mill level, etc. Methods of prospecting differ mainly in the type f drills used. Systems of storage, crushing, and grinding vary chiefly in the types of units. ACKNOWLEDGMENTS Most of the information regarding the early history of the Lehigh cement district was obtained from the History f the Portland Cement Industry of the United States, by Robert W. Lesley, the first president of the Portland Cement Association. The writer is indebted also to Charles Clader, Giant Portland Cement Co. quarry superintendent, for valuable information regarding present and past methods and equipment.

Jan 1, 1931

By Erik Westman, BEN WESTON, SETAREH GHAYCHI AFROUZ, KATHRYN DEHN

One of the most difficult challenges in underground mining is to forecast significant seismic events prior to their occurrence in order to support the safety of miners and to minimize damage to the underground operation. Passive seismic tomography is a tool to image the seismic velocity changes in a rockmass, which can potentially reveal the rockmass behavior before and after a significant seismic event. In this paper, the changes in seismic velocity of the rockmass before and after three major seismic events are investigated to determine whether there are identifiable precursory velocity changes associated with the major seismic events. Conventional mechanics imply that the induced stress at the hypocenter would continue increasing until failure, in the form of an induced seismic event, occurs. With passive seismic tomography we can image changes to the seismic wave velocity distribution within a rockmass and hence infer the changes to the induced stress near the hypocenter. This paper evaluates the hypothesis that induced stress at the hypocenter (as inferred by the p-wave velocity) increases until the seismic event occurs. In addition to analyzing p-wave velocity changes near the hypocenter, changes to the p-wave velocity at “zone centers” were also analyzed. These “zone centers” are regions within the rockmass that consistently have a p-wave velocity that is much higher than the average p-wave velocity for the rockmass. It is found that the p-wave velocity did not increase at any of the three hypocenters prior to the seismic event occurring, however the p-wave velocity did increase in the closest “zone center” for two of the three events.

Oct 12, 2020

By A. H. Cronk

This paper is one of a series being prepared by the United States Bureau of Mines on mining methods and costs in the different mining districts. The mining methods described in this paper are employed by one of the large mines in the Illinois fluorspar district. The mine is located at Rosiclare, Ill., and shipments are made over the Illinois Central Railroad: and by barge on the Ohio River.

Jan 1, 1930

By K. Adham, C. Lee

The demand for nickel is continuing to exceed inventories, and producers are working vigorously to increase capacity. Many nickel processes utilize the fluidized bed technology for its fast heat and mass transfer, excellent temperature control and low maintenance. The following four nickel applications of the fluidized bed technology have been commercialized: I) Sulfide ore roasting; II) Nickel sulfide (matte) roasting; III) Nickel oxide reduction; IV) Nickel chloride pyrohydrolysis. This paper examines the issues surrounding the application of fluidization technology to the above processes, from the stand point of the engineer modeling the process and designing the key equipment, based on the historical success stories and the fundamental principles of flow sheet synthesis. Using the available data in open literature, typical flow diagrams (with convenient bases of 1 t/h feed or product) are developed to illustrate the relative flow rates and to highlight the key features of each application. In addition, some historical background information is provided for each process with supplemental notes with regards to our company's involvements.

Jan 1, 2005

By L. K. Marshall

Last month's engineering fundamentals article discussed some general considerations of underground mine ventilation. This month's article takes a look at auxiliary ventilation-brattice, fans, and ducting-in underground mines. The need for good, efficient auxiliary ventilation increases as mines get deeper and move farther from ventilation shafts. New mining methods and equipment resulted in faster work area advances, liberating more dust, gas, and heat. As a result, worker health and safety requirements in the face area have become more stringent. For all these reasons the safety and efficiency of any underground mine depends heavily on its auxiliary ventilation. The purpose of such ventilation is to supply sufficient quantities of clean air to the face of the drift and to maintain air quality within desired limits until expelled from the mine.

Jan 2, 1982

By John C. Machisak

THE INJURY data and experience at quarries and related plants of the United States are presented in this publication under the following general sections: (A) General injury experience: Tables 1 through 3: Contain current data on the number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 4 and 5: Contain current, data on number of injuries, injury-frequency rates, locution, accident agency, degree of injury, and related employment data. (C) Injury experience by States: Tables 6 through 19: Contain current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data.

Jan 1, 1958

By John B. Knaebel

This paper is one of a series being prepared by the Bureau of Mines on mining methods and costs at various mines in the United States, Canada, and Mexico, and is a description of practice at the Edwards mine of the St. Joseph Lead Co. ACKNOWLEDGMENTS The cooperation and assistance of the officials of the St. Joseph Lead Co. in permitting publication of this paper and providing every facility for its preparation are gratefully acknowledged. Especial thanks are extended R. J. Mechin, manager, R. F. Mitchell, mine captain, and J. S. Brown, geologist, for their generous aid, and the assistance of W. H, Weijola, mine engineer in assembling some of the illustrations is deeply appreciated, The helpful suggestions of C. F. Jackson, principal mining engineer, U. S. Bureau of Mines, are gratefully acknowledged.

Jan 1, 1932

By Kenneth J. Miller

The Bureau of Mines two-stage coal-pyrite flotation process was modified to provide a more concentrated final clean coal slurry underflow which could be dewatered economically by filtration or centrifugation. This was accomplished by doing the first-stage coal flotation step in the conventional manner with a slurry of about 8 percent solids, but running the second-stage pyrite Flotation step with undiluted coal froth concentrate containing about 25 percent solids. The final clean coal underflow produced by the new technique contained between 26 and 30 percent solids; this pulp was sufficiently concentrated to be filtered industrially without further thickening. Sulfur removal was equal to that obtained using dilute second-stage pulp,

Jan 1, 1975

By D La Rosa, D Bennett

"Exploration drill core provides for a number of standard measurements essential for determining the viability of a new mine or the extension of an existing one. Rock lithology and alteration can be visually determined and grade measured from the half core. Geotechnical parameters such as rock strength and structure can also be measured. Using suitable proxies, these metrics can then be used to estimate run-of-mine (ROM) particle size. In combination with comminution test results, these can subsequently be used to design comminution circuit configurations and estimate their performance.The Frieda River Project drill core for the large Horse-Ivaal-Trukai copper-gold porphyry deposit was unusual due to a late stage gypsum-anhydrite stockwork event that overprinted much of the deposit. Above the base of the oxidised zone, which closely matches the water table, gypsum and anhydrite has been leached out, effectively removing the glue holding the rock mass together. As a result, much of the rock above this gypsum-anhydrite surface is fragmented and gravel-like in texture, while the material below this horizon is typically uniform and competent.Large volumes of the orebody above the gypsum-anhydrite surface are expected to need minimal or no blasting for efficient excavation. In addition, the fragmented nature of much of the material was expected to reduce comminution specific energy as it already appears as though it has been crushed. While this was expected to have positive impacts to the operation, the lack of standard geological logging methods available to accurately define the degree of in situ fragmentation led to difficulty in gaining certainty over the ROM product and grinding circuit feed size distributions.Using the extensive library of core photos for the project, a novel method using image analysis techniques to take both the intact core and gravel into account to predict ROM fragmentation was developed. In addition, existing point load test data was used to infer the strength of the rock and its impact on the blasting, crushing and grinding processes. The novel approach allowed development of ROM size distribution data and improved certainty in the results of comminution circuit designs.This paper describes the methodology undertaken in detail, and discusses the results obtained.CITATION:Bennett, D and La Rosa, D, 2016. The Frieda River Project – a Novel Approach to Analysing Exploration Drill Core: How Broken is Broken?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By A Murphy, D Lauder, J Miranda

Minera Alumbrera Limited operates the Alumbrera concentrator, treating a nominal 80 000 tpd of porphyry gold/copper ore. It is located in Argentina, 1200 km north-west of Buenos Aires in Catamarca Province, at an elevation of 2550 m above sea level. Treatment facilities consist of crushing, SAG and primary ball mill grinding circuits, rougher flotation, ball mill regrinding, gravity recovery and cleaner flotation. It is one of only a small number of concentrators in the world, which uses Jameson Cells alone for cleaner circuit flotation. Plant design was started in June 1995, with commissioning commencing in July 1997. Following a successful ramping up to design tonnages and recoveries, a number of options were reviewed to improve gold and copper recoveries. This paper concentrates on a detailed size by size flotation recovery project, commenced in May 1999. Utilising optical microscopy, scanning electron microscopy and analysis of surface chemistry it has allowed losses by size fraction to be quantified and options for enhanced recoveries to be developed. Coupled with extensive circuit surveys it has also provided an insight into previously unknown properties of Jameson Cell operation. Among these are unique residence time and bubble formation reactions to reagent and pulp flow variations, which has permitted a number of novel changes to the operation to maximise capacity and recovery.

Jan 1, 2000

By J. Aiello

"Introduction Byron Creek Collieries Limited Corbin mine is located in southeastern British Columbia approximately 180 air kilometres southwest of Calgary (Fig. I), twenty four kilometres south of Highway No. 3 via a newly constructed provincial road (Fig. 2). The development of the area began July 30, 1905, when D.C. Corbin, a prominent businessman from the northwestern U.S., and his associate E.J. Roberts first visited the site of Coal Mountain on horseback. Coal was in great demand by railways and other industrial users, so the Corbin Coal and Coke Co., after acquiring 6,000 hectares of land in the area, began to develop a mine. Mr. Roberts was responsible for the construction of the 22-kilometre rail spur, the Eastern British Columbia Railway, which joined the mine to the CPR main line at the McGillivray Loop. Rail access to the mine and its developing community, Corbin, B.C., was completed in September 1908, the same year that the first underground mine began production. The Corbin Coal and Coke Co. operated six mines on Coal Mountain (Fig. 3) and production from 1908 to 1930 inclusive totalled 2,120,800 tonnes. This production was allocated to the mines as follows:"

Jan 1, 1985

By M. S. Prasad

In earlier work it has been shown that paper filler clay products can be obtained from primary kaolin deposits of Minnesota. The objective of the current work was to reduce silica and iron contaminants and to maximize kaolin recovery to higher value products suitable for paper coating. This results in achieving a finer and cleaner product conforming to paper coating specifications. Cationic flotation and high gradient magnetic separation were used to remove free silica and iron, respectively, while attrition grinding and ultrasonics have been examined for particle size reduction. The results of this work are presented and discussed particularly with respect to application-oriented product properties. Budgetary estimates are presented for a 200,000 ton/year processing plant based on the process flowsheet developed and optimized by the study.

Jan 1, 1991

By R. M. S. Häggblad

The article deals with stabilisation and regeneration of Ce02 and Ce02/Zr02 based Pt water gas shift catalysts, subject to high initial deactivation. The reaction gas species effect on the catalyst deactivation was investigated by H2-TPR. Activity measurements enabled the effect of different promoters, some added to the Ce02 based catalysts and some to the Ce02/Zr02 based Pt catalysts, to be investigated. The catalysts were also characterised by BET and CO-TPR. Deactivated catalysts activity was restored by using various regeneration methods. Of the two selected carriers the Ce02/Zr02 based Pt catalyst showed the highest resilience to deactivation. For the two different carriers, Ce02 and Ce02/Zr02, Wand Re were the best promoters when the catalyst was subject to deactivation. Experiments with Hr TPR indicate a fast initial change in the platinum oxides concentration and composition. The CO-TPR was used to make conclusions about the various regeneration effects of water and oxygen on the catalyst. Finally it is suggested that not one deactivation mechanism is possible and which mechanism that dominates is dependant on the catalyst and the reaction gas composition.

Jan 1, 2005

By A. Banerjee, J. P. Weiler, J. Jekl, J. T. Wood, R. Berkmortel

"The work presented here is part of an ongoing project designed to develop predictive capabilities of the local mechanical properties, and thus, structural behaviour of a thin-walled high-pressure die-cast AM60B magnesium alloy component. This work focuses on developing correlations between process parameters and local microstructure. Numerical simulations of the die filling and solidification behaviour of the AM60B component were used to estimate local process parameters such as solidification rate, temperature gradient, filling velocity, etc. These estimated parameters were used to establish semiempirical correlations with measured VALUES (of the local microstructure measured in regions throughout the component of different solidification conditions. INTRODUCTIONHigh-pressure die-cast magnesium alloys are experiencing increasing use in structural automotive components. A strength-to-weight ratio comparable to steels and its ease of castability allow for these alloys to be utilized in such capacities as instrument panel beams, seat and door frames, and engine cradles, among others (Gjestland and Westengen, 2007). However, the current use of these alloys is limited due to variations in local mechanical properties. These local property variations restrict part designers to assume lower than actual properties, resulting in larger sections, thus diminishing the light-weighting advantages of magnesium alloys. If these local property variations could be predicted, part designers would be able to optimize die-cast magnesium alloy components and fully take advantage of the light-weighting capacity of these materials.The work presented here is part of an ongoing project aimed at developing predictive capabilities of the local mechanical properties, and bulk mechanical performance, from variations in local microstructure, and ultimately from local process parameters in die-cast magnesium alloys. This project, unique in its nature, is based upon the results determined from fifty sequentially cast AM60B magnesium alloy instrument panel beams provided by Meridian Lightweight Technologies (shown in Figure 1)."

Jan 1, 2012