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The paper considers Aboriginal responses to large-scale mining, including Indigenous attitudes towards land access for exploration and project development. The core question, in which I have been interested for some time (Trigger 1997a; 2000; 2001), is: what are the significant factors affecting responses among Indigenous communities to mining exploration and development project proposals?

Jan 1, 2002

Copper waste dump leaching is growing in importance because of the.large tonnages (up to 250,000 ton/day) of low grade waste rock available from open cut mining of copper deposits and proof that controlled leaching of copper from such dumps can be profitable.Overburden or waste rock, ranging in size from large boulders to fines, is dumped as cheaply as possible on sloping sites. Copper is leached from the dumps by applying up to 12,000 gal/min of leach solution (a combination of spent solution from cementation and make-up water) to the top of the dumps by various techniques.Efliuent from the dumps is sent to a cementation plant for copper recovery.Factors which may be controlled, either directly or indirectly, to give a controlled copper content in the dump efliuent (usually 1-2 g/l.) are the cycle of operations (i.e. the alternate wetting and drying periods), thevolume of solution applied to the dump, pH, Fe2+ and Fe3+ content or redox potential, oxygen content, bacteria and their necessary nutrients, and temperature.Dissolution of oxide copper minerals appears to be mainly a function of acid concentration. Copper sulphide minerals need oxidation for dissolution to occur and this is accomplished by a combination of oxygen,ferric ion, and bacteria. Oxidation of pyrite, oxidation of Fe2+ to Fe3 +, and hydrolysis of Fe3+ are of some importance in leaching practice. The presence of gangue carbonate minerals is detrimental.Physical factors connected with penetration of solution into large rocks are important and the treatment of an individual dump usually extends over a period of many years. Recovery of copper from solution is usually achieved by cementation with iron (usually in the form of crumpled cans) but the use of sponge iron is becoming more important. Iron consumption varies from 1 to 4 lbiron per pound of copper. Preconcentration of the copper in the efliuent solution by solvent extraction followed by electrolysis may become a useful method.Application of dump leaching techniques to metals other than copper depends on finding an economic method of recovering the metal from solution...

Jan 1, 1967

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in' the production of crushed stone. These studies, made at quarries situated in the eastern and southeastern parts of the United States, have not been completed, but to make results available to the industry as early as possible, it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The second, issued in September 1939 as Report of Investigations 3467, dealt with quarry haulage. The present report discusses analyses of time studies of primary drilling at the same group of quarries. OBJECT Or STUDY Pressure of business problems frequently requires the entire attention of quarry management, and in consequence internal plant economies often are neglected. Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that technical studies at a number of plants, made by impartial engineers, might disclose opportunities to reduce costs or improve efficiency in internal plant processes.

Jan 1, 1940

By Anderson Pereira

SORM 3plus (SORM = Superfast Optical Roughness Measurement) is a system enabling online measurement of roughness parameters during continuous strip processing. Increased requirements for new materials and more complex components call for ever increasing process safety. The roughness parameters are important quality features of uncoated and surface refined strips. The traditional method of measurement involves using a mechanical stylus based instrument. For this purpose the operator must stop the production line or samples are taken from the end of the coil and measurements are made offline in the lab. SORM 3plus, however, is a non-contact, online surface roughness measurement system that can be used for metallic and many non-metallic surfaces at strip speeds of up to 2400 m/min. The surface roughness data are stored in the system computer, displayed to the operator and if needed are fed into a higher-level network. The operator is alerted, if the limited values preset by him are exceeded or if any changes within the line will put at risk the production process. SORM 3plus calculates the roughness parameters as defined in the standards, such as the arithmetic average roughness (Ra) and the peak count (RPc).

Oct 8, 2019

By Duclerc Fernandes Parra, Ademar B. Lugão, Nilton Lincopan, Fernanda Esposito, Vijaya Rangari

Polymeric hydrogels are natural or synthetic systems, which have gained interest due to their high biocompatibility with soft tissues. These types of hydrogels have been used for wound dressing as a drug delivery system. Here in this study the polymeric hydrogels based wound healing systems were prepared using poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG), agar and neomycin drug followed by gamma irradiation to promote crosslinking and sterilization. The influence of irradiation process with 25 kGy dose was investigated. The gel fraction and maximum swelling were estimated using physicochemical methods and found about 95% gel fraction and 1100% swelling after 8 h of immersion. Neomycin released from hydrogel was carried out by Liquid Chromatography-Mass Spectrometry method and the drug concentration remained constant for 48 h. Hydrogel/neomycin exhibited antibacterial effects against Staphylococcus aureus. With these results, it can be inferred that hydrogel/neomycin is a suitable candidate for wound dressing.

Mar 1, 2018

By J Seccatore, G Sadao, M Cardu, G De Tomi, L Finoti, F Galvão, J Romero Huerta, A Rezende, J Bettencourt

In the mining industry, rock blasting can be considered as the first phase of comminution. The downstream phases of comminution are mechanical, and consist in consecutive stages of crushing and milling for grain size reduction. The total energy of mechanical comminution depends on grain size and on the resistance of the material to grindability. Usually, the first is quantified by the grain size distribution or one of its KPIs (such as the diameters X50 or X80), while the latter by the working index (WI), representing the amount of energy necessary to reduce the size of grains of a determined amount of material to the desired equivalent diameter (usually expressed in kilowatt hours per tonne – kWh/t). It is widely recognised that it is possible to manage the output of a blast in terms of grain size distribution varying specific charge (powder factor – PF) and charge distribution; specific algorithms such as the KUZ-RAM or the SWEBREC have been created to predict such output. It has also been demonstrated how higher PFs weaken the blasted material by creating micro-fractures that reduce its WI. This paper focuses on a related aspect: the influence of charge distribution on the specific comminution energy in crushing and milling. Small-scale blasts have been performed on 14 marble blocks with different PFs and charge distribution. For every PF, charges have been designed to simulate concentrated and distributed geometries. Concentrated charges simulate opencast blasts with large-diameter holes, with large burdens and spacings. Distributed charges simulate bench blasts with small-diameter holes and reduced burden and spacing. Three control blocks have been fragmented by mechanical means for comparison. For every sample the grain size distribution and the WI in ball mill has been determined. Results show the correlations between charge distributions and the specific energy of mechanical comminution in milling. Finally, the opportunity of adjusting charge diameters and distributions in opencast blasts to improve the output of the comminution circuits is discussed.CITATION:Seccatore, J, Romero Huerta, J, Sadao, G, Cardu, M, Galvão, F, Finoti, L, Rezende, A, Bettencourt, J and De Tomi, G, 2015. The influence of charge distribution on the grindability of the blasted material, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 749–754 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By A. Adu-Acheampong

Stope instability at Ashanti Goldfields Company Ltd. (AGC) is a major concern. Using information from field mapping, major discontinuity sets were defined, Rock Quality Designation (RQD) was determined. The stability of wedges in the stope walls was assessed using the commercially available computer program UNWEDGE(Rock Science, 1992). Analytical results indicate that the presence of graphite infilling in joints contributes to instability, while steeply dipping joints control wedge slabbing and wedge toppling in the hanging wall. Stable stope widths and dimensions were determined to range from8.1 to 30 meters (m).

Jan 1, 2003

By W. K. Connor, O&apos

The U.S. Bureau of Mines investigated the Sheep Creek prospect in the north-central Alaska Range to evaluate the Pb, Zn, Ag, and Sn resources. The studies included field investigations, mineralogical characterization, and concentration tests. Mineralization at Sheep Creek consists of disseminated, banded, and massive pyrite, sphalerite, and galena. Tin occurs as grains of cassiterite (Sn02) in the quartz-mica matrix and within pyrite and sphalerite grains, and Ag occurs in solid solution within the galena. Three bulk surface samples and two sets of core samples were collected at the Sheep Creek prospect for this study. Gravity concentration yielded products with up to 30 pct Sn, and the best result was a product that recovered 52 pct of the Sn at a grade of 22 pct Sn. Bulk sulfide flotation yielded products that recovered up to 89 pct of the Zn, 73 pct of the Pb, and 75 pct of the Ag, but grades were relatively low; selective flotation would significantly increase the grades.

Jan 1, 1989

By T Leidich, M Van Zyl, H Lacy

Mining ‘as usual’, until the most recent decades has resulted in limited landform planning and a general lack of mine waste landform design. Material characterisation, mine planning and dedicated professionals undertaking these tasks were rarely available or in place at the majority of mines. This has led to landform instability, erosion, sediment and poor quality water emanating from mine landforms. In many cases rehabilitation and reclamation failed and these sites have ‘landform features’ that are difficult to relinquish or leave and have little or no apparent land use. In many cases mined landscapes around the world have resulted in a less functional and degraded environment, with deleterious impacts on surrounding ecosystems.This situation is now slowly being addressed, as global companies, academics and practitioners and their organisations have started to exploit the ideas from an integration of earth sciences and mining through the application of planning software dedicated to the design of landforms.This development has had its genesis primarily in the United States. We suggest that process has been driven, in recent decades, by the application of resources in response to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), (USA Congress 11 December 1980) and other mine reclamation legislation enacted by federal and states regulators in the USA. The combining impact has seen a huge transfer of capital back from the public purse and ‘potentially responsible parties’, into abandoned mines to affect control, remediation, and reclamation/rehabilitation of those mines.Given this investment in rehabilitation and reclamation, people engaging in the business of landform planning have had the opportunity to address landform reclamation of historic and active sites. The skills of engineers and scientists with improved technology, waste rock characterisation and modelling tools have been combined resulting in the evolution of landform design and in mine planning of active mines. This has delivered cost-effective, sustainable mine closure designs for over 30 years. Integration of mine design with an understanding of geomorphic principals and the natural landscape, coupled with waste and soil characterisation, yield a positive result. Recently work has been applied across large and small-scale projects by companies. As these processes develop, ideas and concepts are evolving that active mines, or mines in the early planning stages, could use to help reduce double handling, and in the long run reduce overall project and closure costs, more effectively attain the desired final land use, and enhance the industry’s reputation and licence to operate.CITATION:Leidich, T,?Lacy, H?and Van?Zyl,?M,?2014. Application of design concepts and engineering controls necessary to deliver well-designed and rehabilitated landforms, in Proceedings Life-of-Mine 2014 , pp 55–66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By William B. Plank

A NEW record-a quarter million students in the engineering schools of the United States and Canada-has resulted from the great demand for engineers following World War II. The figures released by the American Society for Engineering Education and which appeared in detail in the Journal of Engineering Education for January 1948, show that, on Nov. 1, 1947, 252,250 students were studying engineering in 149 engineering schools of both countries. There are 244,390 in the 143 schools canvassed in the United States, and 7860 in six schools in Canada. These figures include both undergraduate and graduate students and are therefore comparable with the figures in previous presentations on this subject. This unprecedented engineering student body

Jan 1, 1948

By J. A. Bartol

A survey was made of accident data and operating practices related to overloading and uneven load distribution on haulage trucks in noncoal open pit mines. Safety and economic aspects were analyzed. A bibliography of the literature was prepared. Review was made of available or projected systems for weighing or load indicating that might be applied to haulage trucks. A model specification was prepared for an overload detection system. Several promising systems for overload detection were identified. One was installed and tested briefly in a 170-ton rear dump truck in a copper surface mine.

Jan 1, 1982

By Tim Lundquist

Disa Technologies Inc. provides innovative, sustainable solutions for mineral processing and remediation through its patented High-Pressure Slurry Ablation (HPSA) technology. HPSA processes solid feed material in slurry form, propelled by high pressure pumps through opposing nozzles that generate impinging jets within a collision housing. This process induces particle-to-particle collisions in a high energy zone, creating intergranular fractures along grain boundaries. In our batch scale and continuous operating testing, we have found that controlling key processing variables such as nozzle velocity, slurry solids percentage, and the number of passes can allow for controlled size reduction and maximum mineral liberation. Since 2018, Disa Technologies has demonstrated the versatility of HPSA by testing it on diverse materials, including phosphate, copper, uranium, vanadium, zinc, rare earth elements, lithium, nickel, mineral sands, gold tailings, and more. The intent of this paper is to present an overview of our test results describing in detail impacts on size reduction, recovery, and grade with a focus on HPSA's adaptability across ore types. Looking forward, it explores the potential to process materials such as DR-grade iron, clay, PGMs, bauxite, and various tailings. Additionally, it examines planned advancements in HPSA technology, including optimized nozzle spacing, higher capacity models, improved tonnage-to-footprint ratios, enhanced maintenance features, and expanded nozzle configurations.

Jan 1, 2025

By T. G. Sieber, T. D. Tiemann

The extraction of quartz from siliceous iron ores by dissolution in sodium hydroxide solution has been described in detail in AIME Transactions. l923 data reported covered the temperature range from 230-416°F, where a continuous increase in the amount of silica extracted with increase in temperature was found. It is the purpose of this paper to describe some unexpected results of more recent work exploring principally the range of 500600°F where higher rates and greater amounts of silica extraction were antici-p ted. In brief, the experimental procedure consists in digesting the ore under pressure in solutions of sodium hydroxide, filtering the suspension and weighing and analyzing the dried residue for iron content. The amount of extraction is calculated from the weight loss or from the iron analysis of the residue and that of the original ore.

Jan 1, 1969

By Donald A. Voigt

This publication is intended as a guide for persons responsible for obtaining classifications and approvals Tor explosive compounds, mixtures, or devices from the U.S. Department of Transportation (DOT). It deals with the procedures for obtaining a recommendation for classification of an explosive compound, mixture, or device through the Bureau of Mines. Completion of the procedures detailed in this guide is necessary to obtain a final classification of an explosive compound, mixture, or device and assignment of an "EX" number by DOT, which will allow the producer to offer the explosive for shipment within the United States. This guide also gives procedures for obtaining United Nations (U.N.) classification for shipping outside the United States.

Jan 1, 1990

Application of Discrete Element Method for Simulating Feeding Conditions and Size Reduction in Cone Crushers

Sep 13, 2010

By Mahesh C. Meyer Jha

AMAX has developed a chloride refining process to produce pure nickel and cobalt metals from mixed sulfide .precipitates, Metal chloride solutions, generated in a hydrochloric acid leaching step and purified in a solvent extraction circuit, are converted to metal oxides .and HCI gas by pyrohydrolysis. A pilot plant consisting of a 30-inch diameter fluidized bed reactor and other ancillary units was designed, constructed, and operated for over one year. Process design was aimed at minimizing energy consumption, maximizing conversion efficiency, and achieving simplicity of operation and control. The operation provided valuable information on process scale up parameters, process control strategies, and materials of construction., Several process variables such as bed temperature, solution composition, solution feeding system, bed particle size distribution, and fines recycle system were investigated to determine their effects on process efficiency and the physical and chemical characteristics of the product.

Jan 1, 1985

By K. Thirumalai

This study forms a part of Bureau of Mines continuing research on thermal fragmentation of rocks. The potential of internal heating techniques for rock fragmentation is discussed. A concept of rock fragmentation with rapid inter¬nal heating of a localized inner volume of rock is advanced The energy required for rock fragmentation is made available by creating a required vol¬ume of localized heating. The fragmentation of rock using the proposed method is analyzed and qualitatively compared with the results of experiments with Charcoal granite, Dresser basalt, and Sioux Quartzite. High frequency dielec¬tric heating below 100 MHz is used in the study as an example to examine the working of the concept. The selection of operating conditions for the experi¬mental heating is explained. Fragmentation of Charcoal granite and Dresser basalt test rock blocks is achieved for localized heating below 550° C. The heated volume required for fragmentation is observed to be less than 2 percent of the test block volume and the electrical energy consumption is in the order of 3.5 to 6 5 kwhr/m3 The method offers a possibility for in situ fragmenta¬tion of rocks, favorable for internal heating. The method is highly dependent on rock properties governing internal heat generation The efficiency of dielectric heating in the experimental study is observed to increase with increasing dielectric loss of the rock material, ranging from about 10 percent in Sioux. Quartzite to about 50 percent in Dresses basalt

Jan 1, 1970

By Keith R. Vining

Solid fuel, usually coke or anthracite, is commonly added to ground iron ore fines in the pelletising process to reduce the amount of burner fuel required and the maximum firing temperature, while maintaining pellet strength and the productivity of the pelletising plant. However, the use of coke and coal contribute to the production of greenhouse gases (eg carbon dioxide) and are a source of NOx and SOx emissions. Utilising wood biomass / wood char is one methodology CSIRO Minerals is investigating as an alternative to coke and coal, as it is a renewable energy source that is very reactive, has a low ash content and the potential to reduce emissions of greenhouse gases from the iron and steel-making process. Previous work has established that charcoal can effectively replace coke in the sintering process (Lovel et al, 2005), and the following experimental work aims to demonstrate that it can also provide an adequate replacement for coke and coal in the pelletising process. The paper presents the results of an experimental testwork program comparing the behaviour of fired pellets containing traditional solid fuels and charcoal. The physical properties of the pellets are compared in terms of their compressive strength, tumble and abrasion indices and the reduction properties. A qualitative assessment of the pellet microstructures is also presented.

May 1, 2007

DURING September, the Coal Commission pre- pared for issue a series of 18 reports on varied aspects of- the bituminous coal industry; the final report, dated Sept. 22, sums up the facts and offers recommendations addressed to Congress, to the industry, and to the public. The few following paragraphs are selected: Bituminous coal is the real foundation of that great industrial and transportation structure which enables more than a hundred million people to live in America and be so well supplied with things necessary for their health, comfort; and convenience; it also furnishes domestic fuel for two-thirds of the homes of the land. The distribution of the output of the bituminous mines tells the story: 28 per cent. goes to the railroads, 25 per cent. to the boiler houses of factories and mills of all kinds, 15 per cent. to the coke ovens and gas plants, 10 per cent, to the homes, 7 per cent. to steel plants and the same percentage to power plants and street railways, 4 per cent. is exported, 2 per cent is used for power at the coal mines, and the remaining 2 per cent. goes to the seaboard for steamship fuel. Bituminous coal enters into interstate commerce on a scale approached by no other commodity; less than a fourth of the coal mined in the United States fails to enter interstate com-merce. All but one of the 45 coal producing districts in the United States ship coal outside the State in which it is mined. Three hundred miles of cars loaded with coal is the daily output of the bituminous mines of the United States. The public-welfare element in coal is seen in the dependence of public health and safety on an unfailing supply of fuel, in the close connection between the prosperity of most industries and the uninterrupted operation of the coal mines, and in the obvious fact that without coal the great network of railroads which binds together this great country would be idle. The railroads and the public utilities, themselves so clearly obligated to render what-ever public service is demanded of them that the constitutionality of their public regulation is unquestioned, are of all industries most dependent upon coal. Thus, coal makes up over 35 per cent. of the operating cost at the gas plant and over 25 per cent. at the electric power station, and in the operating expenses of. a railroad the cost of coal is the largest single item, next to labor. The practical logic that half a century ago clothed with a public interest the steam locomotive and in later years the electric-power station must recognize a large element of public service in the coal mine that furnishes the necessary energy to both locomotive and power-plant.

Jan 10, 1923

Jan 1, 1924