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By Junwei Han, Wenhua Li, Wenqing Qin, Fen Jiao, Wei Liu, Jiaqi Xu

"A novel technology was developed to study the process of recycling copper from waste printed circuit boards (WPCBs), which are the main source of metal production in the next decades. The chemical compositions of the WPCBs were investigated. The results indicated that the PCB powder was mainly composed of copper (38.5 wt.%), iron, aluminum, and non-metallic materials. Copper is mainly in the form of Cu and is the most valuable metal for the recycle of WPCBs. The concentrated WPCBs powder, obtained by the mechanical process, were pressed as the anode, which was directly electrolyzed to produce copper. The effects of H2SO4 concentration, Cu2+ concentration, current density, pole pitch, and liquid-to-solid ratio on the voltage, current efficiency, and copper extraction were investigated. The results indicated that the optimum conditions were liquid-to-solid ratio of 30 mL/g, current density of 571 A/m2, sulfuric acid concentration of 180 g/L, 50 g/L of copper ion, polar distance of 3 cm. Under the conditions, a desired current efficiency could be achieved. Meanwhile, about 95.62% Cu was recovered from the WPCBs. The experimental studies also revealed that the purity of copper obtained at the highest current efficiency was higher to 99.98%. Produced copper sheet were characterized by X-ray diffraction (XRD). XRD analysis indicated that the copper was the main phase. INTRODUCTION With the rapid development of electronic industry, more and more waste electronic and electrical equipments (WEEE) are generated every year (Fogarasi et al., 2012; Liang et al., 2013). The production of printed circuit boards (PCBs) is the base of electronic industry, because it is the essential part of all electrical and electronic equipments (Schlummer et al., 2007). As a result, a considerable amount of waste PCBs containing plenty of heavy metals have to be treated. In general, PCBs contain about 28% metals that are abundant non-ferrous metals such as Cu, Pb, and Sn. Printed circuit boards can be considered as a secondary resource for recycling rather than wasting. The contents of gold and silver respectively reach 80 g/t and 3300 g/t, which are much higher than that of primary ores. Copper is the main metal of PCB and its content is as high as 26.8% ( Zhang et al., 2009)."

Jan 1, 2018

By J. D. McLenegan

The purpose of this investigation was to prepare a market survey of the refractories industry in California and Nevada (referred to in subsequent paragraphs as the region), and to determine the degree of self-sufficiency and the potential capacity for anticipated growth. The report includes estimates of the total annual refractories consumption, the quantity of refractories imported into the region, the tonnage of raw materials required for their manufacture, and the resources of fire clay and high-alumina minerals in the region.

Jan 1, 1956

By Gerd L. Klinkenborg

Throughout the history of the development of mechanical conveyor systems, it has always been an established condition that loads are received at one end of a single-belt conveyor and discharged at the other end, in a point-to-point, manner. In systems designed for the continuous transport of granular materials, vertical or horizontal changes in; direction have always necessitated two or mope single-belt conveyor units, with a corresponding number of motors, assemblies and attendant mechanical and human or electronic controls. Besides these high-cost factors, every change in the system's direction also calls for a transfer point that involves a drop-back of the material from one level to another with some loss of the material and, in many cases, unwanted additional granulation. Where changes in the location of the discharge point are wanted, the conventional single-belt conveyor must either be replaced by a shorter or longer unit or additional units purchased and installed, or existing units rearranged. This can take days or weeks, and involve special expenditures as well as loss of valuable production time.

Jan 1, 1962

The administration came on as a strong supporter of the mining industry in April of 1982 when President Reagan delivered his long-awaited minerals policy statement. He promised to reduce America's minerals vulnerability, and called for spending billions on meeting stockpile goals for strategic minerals, opening up federal lands for mineral exploration, elimination of barriers to deep sea mining, and regulatory relief. He defended the favorable tax incentives in the Economic Recovery Act as a stimulus to private research and development that would ensure the availability of materials essential to the nation's economy and national defense. But the administration just didn't seem to get anywhere. Congress, environmentalists, and even foreign governments fought White House-proposed legislation on all fronts, delivering the ultimate coup in forcing Environmental Protection Agency Administrator Anne Burford's resignation and the subsequent EPA staff house cleaning in early 1983. Anti-Reaganites scored victory after victory against Reagan's efforts to stimulate the minerals industry. Congress was stalemated on so many mining-related issues that not much was done either for or against the industry. And the US was not to get its way on the issue of sea mining either. Most of Reagan's mineral policy objectives failed to be met. Three months after the National Materials and Minerals Program Plan was presented and the Cabinet Council on Natural Resources and the Environment was made its coordinator, the head of the Cabinet Council James Watt blamed lack of progress in reviving the mining industry and creating a better strategic stockpile on the weak economy and the House of Representatives, which repeatedly thwarted efforts to open wilderness lands to mining. Congress The 97th Congress spent much of its time saying no in 1982-to the Reagan administration's deep cuts in energy and environment programs, to major changes in clean air and water laws, to oil and gas leasing in wilderness, and to killing the Department of Energy. Most of 1982 (and 1981) was spent in heated budget disputes. Some things that did not happen: • The administration and industry failed to get changes in controls of hazardous air pollutants and sulfur dioxide emissions that are implicated in the phenomenon known as acid rain. Industry had wanted to relax requirements for new industries building in clean air regions where the air act demands prevention of significant deterioration (PSD) of air quality, and to relax requirements tightening up the regulation of emissions of hazardous air pollutants. The air battle is expected to continue on five major fronts-acid rain, hazardous air pollutants, PSD, automobile pollution, and nonattainment. • Regulatory reform legislation to overhaul the way government carries out the law died a slow death last year. Business groups and the administration said federal agencies should be required to consider cost-effective measures of reaching regulatory objectives of protecting public health, safety, and the environment. Opponents, including environmentalists, feared such action would delay, weaken, or scuttle important regulations. • Congress turned thumbs down several times on proposals for oil and gas leasing in wilderness but could not agree on any new wilderness recommendations (see The Wilderness Battle). • Congress refused to open the door to the Reagan administration's plan to raise up to $4 billion a year from sales of federal lands. The administration identified surplus and excess federal lands, mostly obsolete buildings or isolated tracts of land, that could be sold by the General Services Administration (GSA) to help out the federal budget deficit. Congress took no action. Some things that did happen: • Congress extended the Defense Production Act (DPA) for six months through March 1983 without changing the 32-year-old law. That came after it failed to resolve sharp differences over proposals for critical minerals programs. Differences concerned both the amount of funds and the scope of programs that would be authorized under the DPA's Title III. Some proponents pressed for $5 billion in funding for loan guarantees or purchase commitments to spur domestic production of minerals such as cobalt. Other members of Congress wanted smaller amounts of funding, and the Reagan administration, until about November, had opposed any use of federal funds for strategic mineral programs. These measures were certain to come up again before the DPA extension expired in March. • House supporters of the Critical Materials Act of 1982 were unable to come up with the twothirds majority needed to pass the bill, so it died on the House floor in December. The bill proposed that a council be established with responsibility for coordinating federal materials research and development. The administration opposed the council creation contending that the Cabinet Council

Jan 5, 1983

By M. Olper

The change in regulations and the strong attention to the environment have suggested some changes in the traditional processes for the recycling of lead acid batteries. Engitec Technologies, marketing the Integrated CX® System, is continuously updating and improving its technology to fulfil the technical, economical and ecological requirements coming from the market and from the environmental authorities. In this paper Engitec Technologies will present the latest technical innovations introduced in the Integrated CX® System.

Jan 1, 2008

Gravity-driven rock falls account for a large proportion of all fatalities and injuries in underground mines. Potentially unstable blocks of rock are found in the hanging wall of excavations, which may be delineated by natural joints or stress fractures. These blocks, referred to as keyblocks, will fail if their weight exceeds the support capacity or if they are located between support units. This paper describes a computer program which simulates blocks in the hanging wall of an excavation based on measured properties of fractures and joints. Keyblocks are identified and placed at random locations in a predefined excavation. The keyblocks are tested against the support to determine whether they fail the support, drop out between the support or are stable. By repeating the procedure several thousand times, statistics of the probability of failure of the keyblocks are obtained. This approach allows the relative hazard associated with different types of support or excavation orientations to be obtained. It is concluded that a probabilistic approach is suitable for the evaluation of supports effectiveness in situations where large numbers of discontinuities or stress fractures are exposed in excavations.

Jan 1, 1998

By M Haest, O Dominguez, D Mittrup

Technological innovations and emerging analytical capabilities are transforming the way drill samples are analysed, with real-time mineralogical analysis made possible. In addition, new business/technical requirements are challenging long standing processes to incorporate more sources of information during planning in order to improve compliance to plan during mining and processing. Unfortunately, the new sources of information that are added do not always have adequate protocols in place to ensure quality data is collected.Spectral data covering the visible – near – short wave – midwave – longwave range are routinely collected by the Geoscience and Exploration department at BHP Billiton Iron Ore for accurate mineralogical identification. These data are used for geological interpretations (logging and modelling) and prediction of physical variables (metallurgical and geotechnical properties).This paper introduces how sampling and quality assurance / quality control concepts have been applied in the spectral data process. The described routine for sampling, data collection/management and reconciliation has been developed to track system precision and accurately and consistently ensure the data is of high quality before it is used across the mining chain.CITATION:Mittrup, D, Dominguez, O and Haest, M, 2017. A new approach to implement quality assurance and quality control to technological innovations – quality of spectral data capture and processes in the minerals industry, in Proceedings Eighth World Conference on Sampling and Blending , pp 265–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

An investigation into the causes of variable sulphur content in blast furnace metal produced at No. 4 blast furnace at the Port Kembla works of Australian Iron and Steel Pty. Ltd. was carried out. Theprogramme included an extended and detailed experimental study of a great number of the operating variables of the furnace, on a cast-bycast or four-hourly basis, over fourteen days.Possible causes of the variation were found in irregular operation due to sinter variability, and it was also clearly shown that slag conditions were most important in controlling sulphur contents of pigiron. Some decrease in sulphur variability was achieved, arising partly from this investigation, and it is hoped to try magnesia additions to modify slag conditions for better desulphurizing.INTRODUCTIONSulphur in pig iron is a problem common to many blast furnace operators throughout the world, but the direct causes and means of overcoming them are functions of the available raw materials, and are hence more particular to each plant and its operating practice. Sulphur in hot metal influences the steel-making operations, the rolling operations and the quality of the finished steel. The main problem associated with high sulphur in steel is "hot shortness", which leads to cracking of ingots and billets in rolling, to poor surface finish and to poor welding properties in the finished steel. On the other hand, sulphur is sometimes a desired additive to steel in order to promote free machining properties.Normal means of controlling sulphur A small degree of control of sulphur in steel is available to open hearth operators by alteration of slag volumes and basicity, but any large degree' of sulphur elimination is...

Jan 1, 1961

By J. D. T. Capocchi, M. B. Mourao

The rate of reaction between iron oxides and carbonaceous materials, agglomerated as pellets, was studied experimentally by measuring the weight loss as a function of time. The effects of temperature, carbon type, inert gas flow rate, pellet size and additions (sodium. carbonate and Portland cement) were determined. It was shown that the value of the apparent activation energy can display large deviations under different experimental conditions; in the present work it was found to be 226.6 kJ/mol. The reaction with coke is slower than with charcoal, and the rate increases as the flow of inert gas in the reaction vessel decreases. Comparison of the rates for pellets of different sizes has shown that for small pellets the initial rate is faster but that it slows down at high conversions owing to the penetration of inert gas into the pellet. Additions of sodium carbonate and Portland cement increase the rate; sodium. carbonate promotes the catalysis of the Boudouard reaction, which is the slowest of the partial reactions. The increase in the rate with Portland cement is attributed to the release of water vapour

Jun 18, 1905

By J. S. Miller

The Bureau of Mines conducted surface tests to determine the feasibility of using liquid explosives for underground rock fracturing. The effects of configuration, confinement, length, critical layer thickness, and fracture-propping sand on detonation and explosive propagation velocity of desensitized nitroglycerin were studied, using polymethyl methacrylate and glass-plate reservoirs through lengths from 3 to 12 ft, with explosive-layer thicknesses from 0.1875 to 0.0312 in and in aluminum tubes 8 ft long with diameters from 2.000 to 0.125 in. Interval and continuous detonation velocity data were obtained. Under the test conditions detonation velocity was dependent upon explosive confinement and fracture-propping sand. The detonation velocity of a confined nitroglycerin explosion in aluminum tubes can be reduced by as much as 85 percent, when the tube contains fracture-propping sand. The shape of the reservoir, whether triangular or rectangular, has little effect on the detonation velocity or explosive propagation. The critical or minimum explosive-layer thickness between glass plates, capable of supporting propagation, was 0.0312 in. The presence of a fracture-propping sand in the sheetlike layers increased the critical explosive layer thickness to 0.0625 in. In nitroglycerin-filled and nitroglycerin-sand filled tubes, the minimum tube diameters successfully tested were 0.125 in and 0.375 in, respectively.

Jan 1, 1969

By Alla D. Mah

The need for more and better basic thermodynamic data for the oxides of many of the rare metals is evident to anyone who attempts thermodynamic calculations involving these substances. In continuation of a Bureau of Mines program to meet this need, this paper reports new experimental values of the heats of formation at 298.15° K. of the hexagonal crystalline variety of germanium dioxide and germanium dioxide glass. The values were obtained by means of combustion calorimetry and sodium hydroxide-solution calorimetry. The calorimetric results also made possible the derivation of values for the heat and entropy of fusion of hexagonal germanium dioxide at its melting point. The newly measured data were combined with previously known entropy and high-temperature heat content values to obtain heats and free energies of formation of germanium dioxide (in the hexagonal crystalline, glassy, and liquid states) over the temperature range from 298.15° to 2,000° K.

Jan 1, 1962

Provide the mining industry with a simple, accurate and readily available means of measuring the gas flow from pipe outlets such as gob holes Approach The Bureau of Mines conducted laboratory studies to establish correction or method factors for anemometers when used to measure gas flow from pipe outlets. Using the Anemometer Anemometers are used by the mining industry to make air velocity measurements in mine entries. Although the instrument has no appreciable influence on the airstream in mine entries, especially since the cross-sectional area of an entry is much larger than the cross-section of the anemometer, correction or method factors are used to correct the center line anemometer velocity to average velocity. This adjustment is made because the air velocity in a mine entry is highest in the center and lower at the sides. Anemometers can be used to measure gas flow from small diameter pipe outlets; however, since the instrument diameter is much larger than one-sixth of the pipe diameter, it will influence the air-stream from these small outlets. Resulting velocity measurements are erroneously high by as much as 30 percent. Method factors must be applied to such anemometer measurements taken at pipe outlets. Through a research investigation the Bureau of Mines established a set of method factors for center-line anemometer readings taken at the discharge end of 4-to 8-inch diameter pipes. These method factors were combined with method factors which were developed by the National Coal Board of Great Britain for 12-to 30-inch diameter pipes. The anemometer was mounted on the end of a short rod and held against the pipe for support except on the 4-inch pipe where the instrument was started and stopped remotely to prevent hand interference with the air-stream during measurements. Method factors were determined by comparing the anemometer measurements at the pipe outlet to the true average airflow which was simultaneously determined upstream by venturi measurements. Consequently, a method factor is nothing more than the ratio of the true velocity to an anemometer measurement.

Jan 1, 1987

By R. W. Baker

"The development of uppers drilling at Brunswick Mining is reviewed. This paper describes design criteria for drilling patterns and the research required for selection of a suitable drill jumbo. The success of the uppers drilling program based on operating procedures is highlighted. IntroductionBrunswick Mining and Smelting Corporation Ltd., operates a 10 500 tonnes per day lead /zinc/copper I silver underground mine some seventeen miles southwest of Bathurst, New Brunswick .The No. 12 orebody, first discovered in 1952 by a group headed by M.J. Boylen, had extensive development, including two shallow shafts (500 ft), and test work carried out on it by St. Joe Lead between 1953-1957. However due to complex metallurgy and depressed metal prices, the operation was suspended.In 1961, a group comprised of M.J . Boylen, K.C . Irving and Patino acquired the rights of St. Joe Lead to the No. 12 property. A concerted development plan was initiated along with construction of the necessary sur face facilities and by July 1964, the property was in production at 4500 tons per day.In 1967 Noranda Mines Ltd. acquired operating control of Brunswick Mining and Smelting Corporation Ltd."

Jan 1, 1988

By S A. Ravishankar

In heavy minerals separation, the titanium and iron oxide phases are separated from silicates in the coarser particle size range (80 - 150 mm) using magnetic and electrostatic separators. With the ongoing challenge of heavy mineral ore deposits getting increasingly finer in particle size, conventional separation equipment suffers from the ability to process this material at the same throughput rate as coarser particles. A variety of magnetic separation technologies were developed to perform at a much finer particle size range, down to 2 mm in the clay industries mainly to remove titaniferrous oxide particles. Complementing the developments made on the physical aspects of magnetic separation, Cytec Industries has recently developed a ‘bolt-on’ chemical enhancement technology for magnetic separation (CEMS). This is to enable separation of finer particles, and weakly paramagnetic titanium phases from diamagnetic silicates that are not amenable to magnetic separation. This paper will provide an outline of the technology, illustrate its ability to process a wide variety of ores, and also discuss plant limitations. The major advantages of chemical enhancement technology to magnetic separation includes: simple dosing equipment extension to existing magnetic separation technology; ability to produce product of comparable quality with improved cost effectiveness, when compared to incumbent flotation; removal of impurity minerals over wider size range; enhanced removal of non-magnetic impurities; and improving the process robustness. Furthermore, chemical enhancement technology for magnetic separation has also emerged as a platform for removing impurities at lower levels in other mineral systems as well.

Oct 5, 2011

An experimental study of the soil mechanics of brown coal showed that brown coal consolidates in the same manner as does a clay and that the theory of consolidation for soils may be applied to brown coals. Moisture content is a function of the coal type, the existing effective stress, and the stress history of the coal.The effective stress in a brown coal seam is a function of the overburden pressure, the pore stress and tectonic stresses. Stress history may be deduced from geological evidence and determined by consolidation tests. Application of these principles to the brown coal seams of the Latrobe Valley shows that the distributions of natural moisture contents are consistent with consolidation.INTRODUCTIONThe nature and geology of the brown coals of Victoria, particularly of the Latrobe Valley, were discussed in some detail by Edwards (1945, 1948), Thomas and Baragwanath (1949) and Gloe (1960). A salient feature of these studies was the distribution of moisture contents in the brown coal seams. Recent experimental work, part of a soil mechanics study of the structure and strength of brown coal, showed that moisture content variation is a reflection of consolidation phenomena in brown coal and application of the results to .field condItions verified and modified the conclusions of Edwards in his pioneer work. Further detail of this experimental work is recorded elsewhere (Rosengren, 1961).EFFECTIVE STRESS AND CONSOLIDATIONEffective stresses in soilsA saturated soil is a two-phase system, consisting of a compressible skeleton of rigid soil particles and pores filled with water, an incompressible fluid. (In this context, the terms compressible, incompressible, and rigid are relative only and refer to orders of magnitude). If this system is subjected to stress we define...

Jan 1, 1963

By Dae S. Young

A new probabilistic approach is introduced for slope stability analysis including adverse impact of blasting vibrations. The material strength within a slope area is randomized in this bi-variate joint probability analysis. To be a completely general engineering method, the new probabilistic approach employs the random variable transformation technique; the Hermite model of the Gaussian transformation function, which transforms the experimental histogram of strength values to the standard Gaussian variables. Because bi-normal joint probability is analyzed on the true probability region projected on the Gaussian transformed variable plane, it is an exact solution of slope stability based on the available sample data. Details of the probabilistic approach are given through a case study on an iron ore mine. The case study demonstrated that the probabilistic approach is effective and simple enough to be a routine engineering practice for slope analysis.

Jan 1, 1984

By H Aoki, A Nakayama, K Morita, S Yamada

The thermal conductivity of mold flux is crucial for optimising the productivity and quality of steels. This study investigates the thermal conductivity of molten oxides, including CaO-BO1.5-AlO1.5 (CBA), CaO-BO1.5-AlO1.5-SiO2 (CBAS), and CaO-MgO-BO1.5-AlO1.5 (CMBA) melts, using a hot wire method. Additionally, their structure is examined using Raman spectrometry and magic angle spinning nuclear magnetic resonance (MAS-NMR) to explore their relationship. Furthermore, first-principles calculations are employed to assess the covalency of each bond in the melts for a more quantitative analysis of their relationship. The study confirms that an increase in the CaO concentration of the CaO-BO1.5-AlO1.5 melts reduces the amount of bridging oxygen and consequently decreases thermal conductivity. The covalency of the B[4]-O bond is highest, especially when the second-nearestneighbour Al atoms transition from Al[6] to Al[4], forming the AlB3O7 structure with B[4]. The relationship between thermal conductivity and the structure of CaO-BO1.5-AlO1.5-SiO2 melts can be quantitatively assessed using the degree of polymerisation of the network structure and the variation of covalency as indicators. Furthermore, replacing CaO with MgO in the CaO-MgO-BO1.5-AlO1.5 melts reveals a mixed alkaline earth effect on thermal conductivity.

Aug 21, 2024

By Peter J. Tarkoy

A great deal of attention has been directed toward the complexities and inadequacies of exploration and pre-bid geotechnical information for heavy construction projects, differing site conditions, and the adversary relationships which generally develop as a result. The adversary position has been maintained at all cost. The solution is simple, if not easy. The solution requires strict and equal adherence to given principles by all parties involved, throughout the life of the project, from conception to completion. It is necessary to review and redefine some basic concepts, without value judgements, from a context of getting the job done. In a recreated context, the role of truth, judgement, responsibility, and integrity, in exploration, engineering design, construction estimating, and project construction, will be examined. It is suggested that anticipated geotechnical conditions be defined unconditionally. The alternative choice is to give the bidder the opportunity of making the interpretive judgements based on geotechnical data. Similarly, a unilateral method of establishing encountered conditions that are agreeable to both owner and contractor, must be outlined prior to contracting. As anticipated and encountered conditions are firmly and accurately established, significant differences can evaluated based upon limitations specified in the contract documents. Impact of differences on project costs can be fixed by pre-defined methods.

Jan 1, 1983

By Shahram Tafazoli

This article presents a novel technology for sensing the size of rocks after blasting in hard rock mines. Blast engineers require rock size statistics to carefully adjust the blasting parameters. The rock fragmentation requirements vary depending on the ore type and crusher specifications. The most popular statistical parameters in the industry are the so-called P numbers (e.g., P80 and P100). A machine vision based system is introduced here for automatic image collection and fragmentation analysis of the material right inside the bucket or dipper of mining shovels. A heavy-duty camera provides the required imaging data to an embedded computer mounted inside the cab. A custom machine vision software continuously analyzes the captured bucket images and stores the suitable ones in local storage which are then fed to a Desktop software for automatic fragmentation analysis. This technology has been developed by Motion Metrics International and is commercially available as FragMetrics?.

May 1, 2009

By Neale R. Neelameggham, Ganesan Subramanian

Anthropogenic Heat Flux (AHF) is defined as heat generated from use of non-renewable energy by humans in residential, commercial and industrial activity. State of the art Global Circulation Models (GCM) used to predict global impacts of climate change to help set related policy do not include this heat flux. AHF is considered to be a much smaller an insignificant forcing, solely based on the global mean values. Various Climate models have discussed the “Heat Island Effect ” in high AHF areas. Through the use of simple climate models, it is shown that significant pockets of AHF can impact climate locally in ways significant enough to impact global climate. Inclusion of spatial AHF distribution, rather than a global mean value is important to accurate modeling either on a regional or global scale.

Mar 1, 2017