Search Documents

SOME notes on the works of the Electrolytic Refining and Smelting Company of Australia will no doubt be of interest to members of the Institute, more especially as much of the work is new to Australasia. As many of the members who may read this paper have not been in a position to visit works of this kind, and are consequently not thoroughly acquainted with all the operations carried on, the author has taken the liberty, in some cases, to enter into explanation which would otherwise be unnecessary. The works are situated at Port Kembla (New South Wales), about fifty miles south of Sydney, and are approachable both by rail and water. The Government has recently built a low-level jetty upwards of five hundred feet long, and intends installing at an early date an electrically operated portable crane to facilitate the handling of material to and from the boats. This will mean: a considerable reduction in the length of time that boats are laid up at the jetty. There are also under construction two breakwaters, which, when complete, will materially assist shipping operation...

Jan 1, 1910

By Osamu Inoue, Takashi Yamashita, Takashi Ikemoto

The expansion project in Naoshima smelter and refinery to meet enhancing recycling business of E-scrap was successfully completed in 2016 to have a capacity of 110,000 tpa of E-scrap treatment. Increasing treatment of E-scrap has raised the Ni content of copper anode to 4000 ppm on average, which is double the level of 10 years ago, and to 6000 ppm or more occasionally. The tank house has refined such copper anode to copper cathode with starter sheets. Since most Ni in Copper anode dissolves in copper electrolyte, the Ni content of the electrolyte has increased to 27 g/L and more. Ni accumulated in the electrolyte has increased power consumption during the electrolytic refining of copper, although cathode quality has been controlled satisfactory so far. In order to ensure sustainable operation while growing E- scrap business, the NiSO4 process has been expanded recently so as to recover Ni in the electrolyte more and the pressurized-leaching technology will be introduced to the slime leaching process so as to enhance the capacity of slime treatment and to improve Ni recovery in the near future. INTRODUCTION In recent years, the treatment amount of E-scrap at Naoshima smelter and refinery has increased according to the growth of its recycling business as shown in Figure 1, while impurities from E-scrap have concentrated in copper anode as well. Especially, Ni content in anode has been increasing remarkably since 2012, causing to raise Ni content in the electrolyte as shown in Figure 2. The increment of Ni content in copper anode and electrolyte has adversely affected the electrorefining process, slime leaching process, and NiSO4 crystallization process at the tank house. Such severe conditions provided opportunities to redesign the tank house to establish a robust process to which more Ni is acceptable.

Jan 1, 2019

By Alexander Burns

Electrolytic salt splitting is a technology where acid and/or base is regenerated from a neutral salt using membrane electrolysis. Recent advances in the understanding of brine treatment, membrane stability, and cell design have made electrolytic salt splitting feasible on certain hydrometallurgical solutions. Meanwhile, environmental regulations have made the bulk disposal of salt solutions more difficult. In this paper, sodium sulfate salt splitting is examined from a cost perspective, compared to purchasing the reagents directly. Relative costs are estimated for several regions based on published electricity and reagent prices. The results show that salt splitting is economically favourable in some regions, and can be made more favourable by applying modifications to the traditional three-compartment desig

By R. P. E. Hermsdorf

THE electrolytic refining of metals for the removal of undesirable impurities has become a recognized necessity in the nonferrous field. Copper, lead, zinc, nickel, silver and gold have been produced in this manner for years. The United States Metals Refining Co., realizing that considerable quantities of lead and tin could be made available to the trade if a satisfactory method of purification of these metals could be established, decided to investigate the possibilities of electrolytic solder. In cooperation with Dr. Edward F. Kern, of the School of Mines at Columbia University, the company developed a process of electrolytic refining of lead-tin alloys using a tin-lead fluosilicate electrolyte. A pilot plant was installed in November, 1927, and the commercial unit was put in October, 1929. Since that time thousands of tons of electrolytic solder have been produced in this plant and consumed by all branches of industry that use solder.

Jan 1, 1936

By S. R. Stopic

The EU-financed INTREAT Project (Integrated treatment of industrial wastes to¬wards prevention of regional water resources contamination) addresses the environmental pollution associated with solid and liquid wastes/effluents produced by complex sulphide ore mining and metallurgical activities. The results concerning the electrolytic recovery of cop¬per from effluents formed after mixing of streams from Copper Refining, Precious Metals Plant and Electrolyte Regeneration in the Balkan Area will be shown. The waste water is characterized by low pH values and high contents of heavy metals, such as Cu, Ni, Bi, As, Sb. The majority of these waste water flow untreated into the natural water streams and through the network of existing rivers, which end up in the river Danube. The influence of current density and flow rate on the deposition rate, the quality of copper and the process efficiency will be presented. The full continuous process is based on cells with rotating disc cathodes and represents a pre-treatment step before common neutralisation in a cascade line

Jan 1, 2007

By N. J. Bunce, B. Vollick, A. F. Souza, D. Bejan, P. Maharaj, C. Shamshoom

"Copper electrodeposition from synthetic and authentic acid mine drainage (AMD) is inhibited by ferric iron (Fe(III)), through re-oxidation of copper. Polarization to –2.5 V versus standard hydrogen electrode prevents the dissolution of predeposited copper from the cathode. Above pH 1, copper deposition is independent of Fe(III) concentration to approximately 25 g/L. Fe(III) is reduced to ferrous iron (Fe(II)), with a high combined current efficiency for iron and copper reduction. In a divided cell, the conversion of Fe(III) to Fe(II) is almost quantitative, with efficient transfer of acidity from catholyte to anolyte. Prospects for developing electrochemical technology for complete remediation of AMD are discussed.RÉSUMÉ En raison de la réoxydation du cuivre, le fer ferrique (Fe(III)) nuit à l’électrodéposition du cuivre à partir de drainage minier acide (DMA) véritable et synthétique. Une polarisation à -2,5 V par rapport à l’électrode standard d’hydrogène empêche la dissolution du cuivre déjà déposé de la cathode. À un pH supérieur à 1, la déposition du cuivre est indépendante de la concentration en Fe(III) jusqu’à environ 25 g/L. Le fer ferrique est réduit en fer ferreux (Fe(II)) avec une efficacité combinée élevée pour la réduction du fer et du cuivre. Dans une cellule divisée, la conversion de Fe(III) en Fe(II) est près de la quantité théorique, avec un transfert efficient de l’acidité de catholyte à anolyte. Les perspectives de développement d’une technologie électrochimique pour la remédiation complète du DMA sont discutées."

Jan 1, 2016

C. A. HANSEN (communicated appendix*).-Since the above paper was written, tests have been conducted with a view to securing a sounder basis for discussing the effects of temperature on the behavior of the zinc cell. The following data, while making no pretense to great accuracy, are still reasonably close. Cells were operated with the same feed solutions, but at varying temperatures, the latter being controlled by means of immersed steam coils. Current efficiencies obtained indicate that the corrosion rate

Jan 11, 1918

By W. H. Hannay

Introduction The subject matter of this paper will be treated under two heads: (1) experimental work and the development of the purification system, and (2) the operation of the commercial plant. During 1927-28, a two-ton slag-retreating plant was in operation at the smelter for experimental purposes. Details of this operation and of the commercial plant are presented in a paper by G. E. Murray, read before the Annual General Meeting of the Institute in April, 1933 (1). A point which has considerable bearing on the subject of the present paper, and which was not emphasized by Mr. Murray, is the concentration of volatile impurities in the zinc oxide fume produced. The result of the operation of the slag fuming furnace is largely to confine in a closed circuit all the minor constituents of the Sullivan concentrates, both lead and zinc. They pass into the feed of the zinc fuming furnace, with the result that all impurities which volatilize-such as arsenic, antimony, tin, fluorine, etc.-report in the zinc oxide product. The accompanying condensed flow-sheet (Figure 1) will illustrate this. The only outlet for impurities which is not shown is the small tonnage which passes the Cottrell plants. The flow-sheet would indicate the possibility of building up a prohibitive concentration of cathodic impurities in the oxide leaching plant feed. However, after three years' continuous operation this has not occurred. Should this condition arise at some future date, discard of some tonnage of blast furnace slag is indicated. In Mr. Murray's paper, the much greater flexibility of blast furnace operation, due to the slag fuming furnace, is stressed, particularly as to the lead content of the slag. The requirements of our lead refinery call for a bullion containing about 0.70 percent antimony.

Jan 1, 1934

By P. A. Treasure

The EMEW® cell has been developed to overcome a number of inherent limitations in conventional electrowinning technology, particularly the high cost and restricted process windows characteristic of conventional hardware. The technology has been widely demonstrated to achieve high performance for various metals under chemical conditions well outside the limits required for efficient operation of conventional cells. This process flexibility offers significant opportunities for cost savings. in recovery of zinc from primary and secondary sources. The EMEW® technology is now available on a fully engineered basis, as a versatile commercial alternative to conventional electrowinning hardware. Application of the EMEW® cell for recovery of secondary zinc material offers significant advantages to the recycling industry. For example, a selective caustic leach can be used where there are high levels of iron or other contaminants in the target material. The reagent requirement is minimal as most of the caustic is regenerated in the bell and zinc dust that may be required for electrolyte purification is produced in the cell. A high purity zinc powder or cathode is produced in the cell. In the case of acidic zinc electrolytes, the cell is capable of operating over a much wider range of operating conditions than a conventional cell.

Jan 1, 2000

By I. Chatterjee, M. Misra

The principle of microwave drying of fine coal is based on the selective absorption of microwaves by water. Coal is a poor absorber of microwaves. As a result, water can be removed from fine coal by selectively heating water molecules. One of the difficult problems during microwave heating is the exact determination of temperature in the core of the materials. The electromagnetic energy absorption in coal/water mixtures during microwave drying is controlled by several factors including the dielectric properties of the constituents. In this paper, electromagnetic and thermal models of coal are presented that can predict the energy absorption and temperature distribution during microwave drying.

Jan 1, 1992

By David G. Paton

"Electromagnetic surveys were conducted at the BXL Bulk Explosives Limited Mixing Plant andsurrounding area to characterize runoff from the site and possible impacts of salinity. The BXL Plant is located at the edge of a depressional area and any escape of soluble ions, such as nitrates, would have ended up in the slough to the west of the plant. Two electromagnetic (EM) instruments were used in the survey. A Geonics EM 3 1 was used in October 1997 and in June 1998, a new multifrequency instrument, a GSSI GEM 300 was also tested. Both instruments were individually mounted on a plastic sled with Teflon runners and towed with an ATV quad. Position was determined using a Trimble Pro XL global positioning system (GPS) with a real time correction mode Landstar receiver for an accuracy of about *l m. Both GPS and EM instruments were set to collect data at 1 second intervals. The quadrature maps for both instruments showed essentially the same information, namely of very high conductivity, appearing to emanate from the mixing plant. The levels of conductivity were highest where the saline water appeared to pool, at the southern end of the slough. Soil sampling locations were identified from the EM maps and navigated to using the real time GPS. Composite samples were collected by hand using a Dutch auger, from two locations, in increments of O-1 5, 15-30, 30-60 and 60- 90 cm. The analysis of the soil samples indicated a complete absence of nitrate or ammonium ions; the major anion was sulphate, indicating naturally saline subsoil conditions. The GEM 300 made the collection of data more efficient, as only one pass was required to collect the data from four depth intervals. The EM survey combined with the real time GPS allowed rapid characterization of the site with respect to soil salinity and proved to be cost-effective for Phase l/ Phase 2 site assessments and targeting sampling locations."

Jan 1, 1999

By J. Durkin

The Bureau of Mines has conducted field studies in coal mines throughout the United States to determine the effectiveness of electromagnetic techniques in locating miners trapped underground following a mine accident. Data from these tests have been used to generate models of expected signal and noise distributions as found above these mines. These distributions have aided in placing the expected performance of a through-the-earth electromagnetic communications technique into a probabilistic framework. Results show that at a 10% false-alarm rate, the expected probability o detecting a miner's signal" from a depth of 1000 ft is 54% at 500 ft it is 95%. These depths exceed the actual depths of 90 and 50%, respectively, of United States coal mines. Sensitivity studies have shown that at depth of 1000 ft, the probability of detection will improve approximately 2% for each dB of increase in signal-to-noise (SNR) ratio.

By L. Yan, B. Lambie, J. Srednicki, J. Carr

Electromagnetic emissions from electrical devices may interfere with electronic safety systems or other devices in the mining environment. This electromagnetic interference (EMI) may cause unwanted changes in the performance of the affected devices and may cause safety issues for miners. To minimize the risk of EMI, the National Institute for Occupational Safety and Health (NIOSH) has conducted research quantifying the electromagnetic emissions of several types of equipment that might be used in the mining environment. Previous research has shown that welding arcs can give off ultraviolet (UV) emissions, visible light, and infrared (IR) emissions that can cause health problem on skin and eyes. In this study, the electromagnetic emissions of the shielded metal arc welding (SMAW) process were monitored and measured. Several factors including operating mode (AC, DC positive or DC+, DC negative or DC-), current setting (low, medium, high, maximum), and electrode type were investigated to compare their effect on emission level. The test shows that the emission level from the welding process can be affected by those factors. The test data also shows that, among those factors, the operating mode has more influence on emission level than do current setting and electrode type. The information in this paper can be useful for the mining industry to better understand the emission in the 9-kHz to 500-MHz frequency range from a SMAW welder.

Feb 1, 2023

By Nagy El-Kaddah

"One of the emerging technologies for the production of ultra-clean metals is electromagnetic filtration. The theory and the mechanism of electromagnetic separation of inclusions from molten metal are briefly reviewed along with basic electromagnetic separation systems. This paper focuses on inclusion removal in the induced current separators, with specific reference to a new separator developed at the University of Alabama. A simple analytical model is presented for the analysis of particle separation in such a system. The role of the applied magnetic field on inclusion removal will be discussed. It is shown that particle velocity increases exponentially with increasing magnetic field strength. At moderate field strengths, the velocity of 50 to 100 u. inclusions· are an order of magnitude larger than those achieved by buoyancy. The separator developed at the University of Alabama is described together with experimental results of laboratory and large scale experiments on purification of molten aluminum. These results demonstrate the capability of the system for producing super-clean metals.IntroductionThe nature of extraction, refining and processing of metals is such that oxides and other non-metallic particles will always be present. This is due to the highly reactive nature of metals with oxygen and other non-metallic elements. The presence of these type inclusions in metals, even in minute amounts, can seriously flaw the reliability and performance of the final product. They not only reduce the strength and the stiffness of the metal/1/, they are the reason behind many of manufacturing defects such as porosity in castings, surface and internal cracks in continuously cast ingots and rolled products, etc., which act to cause premature failure of manufactured parts. In fact, for critical applications such as turbine blades, there is virtually no tolerance for inclusions above ten microns in size /2/. Therefore, removal of inclusions from the liquid metal is an essential processing step.The demand for cleaner metals has brought major changes in the technology and practice of metal refining and casting. Inclusion removal from the melt is currently achieved by passing the melt through a series of melt treatment systems, including induction stirring furnaces, argon-stirred ladle, and ceramic foam and deep-bed filters /3,4/. These systems are generally capable of removing all inclusion particles above 50 microns in diameter, which meets current cleanliness requirements for most applications. However, they may not be able to meet the projected cleanliness levels for critical applications due to kinetic and operational limitations of these systems in removing smaller particles /5/."

Jan 1, 1996

By Nagy El-Kaddah

One of the emerging technologies for the production of ultra-clean metals is electromagnetic filtration. The theory and the mechanism of electromagnetic separation of inclusions from molten metal are briefly reviewed along with basic electromagnetic separation systems. This paper focuses on inclusion removal in the induced current separators, with specific reference to a new separator developed at the University of Alabama. A simple analytical model is presented for the analysis of particle separation in such a system. The role of the applied magnetic field on inclusion removal will be discussed. It is shown that particle velocity increases exponentially with increasing magnetic field strength. At moderate field strengths, the velocity of 50 to 100µ inclusions are an order of magnitude larger than those achieved by buoyancy. The separator developed at the University of Alabama is described together with experimental results of laboratory and large scale experiments on purification of molten aluminum. These results demonstrate ?the capability of the system for producing super-clean metals.

Jan 1, 1996

By Miguel Reyes, Chenming Zhou, MATTHEW GIRMAN

This paper is aimed at helping the mining industry to better understand the challenges posed by electromagnetic interference (EMI) and to promote electromagnetic compatibility (EMC) in underground coal mines. The paper begins with a review of EMI standards in other industries, then presents some representative examples of EMI instances that have occurred in the mining industry, followed by a literature review of published EMI research in mining and, finally, a discussion on mitigation strategies and practical considerations related to EMI in mining.

By R. J. Matetic, J. Noll, C. Zhou, J. DuCarme, M. Reyes, J. Srednicki

"In April 2016, the U.S. Mine Safety and Health Administration (MSHA) began requiring the use of continuous personal dust monitors to monitor and measure respirable mine dust exposures to underground coal miners. Mines are currently using the PDM3700 personal dust monitor to comply with this regulation. After the PDM3700’s implementation, mine operators discovered that it interfered with proximity detection systems, thus exposing miners to potential striking and pinning hazards from continuous mining machines. Besides the PDM3700, other electronic devices were also previously reported to interfere with proximity detection systems. MSHA sought the aid of the U.S. National Institute for Occupational Safety and Health (NIOSH) and mining industry stakeholders to determine how the PDM3700 and some other electronic devices and proximity detection systems interact with each other. Accordingly, NIOSH investigated existing standards, developed test protocols, designed experiments and conducted laboratory evaluations. Some interferences were observed to be caused by electromagnetic interference from some electronic devices, including the PDM3700. Results showed that there was no significant interference when the PDM3700, as well as other electronic devices, and the miner-wearable component of the proximity detection system were separated by distances of 15 cm (6 in.) or greater. In the present study, it was found that the PDM3700 and the personal alarm device needed to be at least 15 cm (6 in.) apart in order for them to be used simultaneously and reduce potential interference. IntroductionUnderground coal miners are exposed on a daily basis to a variety of hazards, such as coal dust exposures, high noise levels, roof and rib falls, potential for fires and explosions, and operating and working with heavy machinery. One of the hazardous jobs is that of operating or working near a continuous mining machine. According to U.S. Mine Safety and Health Administration (MSHA) statistics, 44 miners had been fatally struck or pinned by a continuous mining machine since 1984. In an effort to prevent future striking and pinning fatalities from occurring, proximity detection systems have been developed and are required on all operating continuous mining machines in underground coal mines, with the exception of full-face continuous mining machines, by 2018 (MSHA, 2015a)."

Jan 5, 2018

By Miguel Reyes, Mathew Girman, Chenming Zhou

Modern smart mining increasingly depends on sophisticated electrical and electronic systems for improved safety and productivity. With more electronic systems being introduced underground, the mining industry faces electromagnetic compatibility (EMC) issues caused by electromagnetic energy emitted by one device adversely impacting the normal function of another. This paper provides an overview of EMC and electromagnetic interference (EMI) research for underground mining, including a review of EMI in other industries applicable to mining, published EMI research pertaining to mining applications, representative EMI incidences, related EMI legislation in mining, and mitigation strategies.

Jan 3, 2022

By R. J. Matetic, J. Noll, C. Zhou, J. DuCarme, M. Reyes, J. Srednicki

"In April 2016, MSHA began requiring the use of continuous personal dust monitors (cPDMs) to monitor and measure respirable mine dust exposures to underground coal miners. After the cPDM’s implementation, mine operators discovered that it interfered with proximity detection systems (PDSs), thus exposing miners to potential striking and pinning hazards from continuous mining machines. NIOSH was sought out by MSHA and mining industry stakeholders to determine how the cPDM and PDS interact with each other. Accordingly, NIOSH investigated existing standards, developed test protocols, designed experiments, and conducted lab evaluations. Some interferences were observed to be caused by electromagnetic interference (EMI) from the cPDM. Results showed that there was no significant interference when the cPDM and the miner-wearable component of the PDS were separated by distances of 6 inches or greater. In this study, the cPDM and PAD needed to be at least 6 inches apart in order for them to be used simultaneously and reduce interference potential. INTRODUCTION Underground coal miners are exposed to a variety of hazards on a daily basis such as coal dust exposure, high noise levels, roof and rib falls, the potential for fires and explosions, and operating and working with heavy machinery. One of the hazardous jobs is operating or working nearby a continuous mining machine (CMM). According to Mine Safety and Health Administration (MSHA) statistics, 40 miners have been fatally struck or pinned by a CMM since 1984. In an effort to prevent future striking and pinning fatalities from occurring, proximity detection systems have been developed and are required on all operating CMMs in underground coal mines, with the exception of full-face CMMs, by 2018 (1,2). Proximity detection systems (PDSs) are designed to alarm miners and stop machine motion in order to protect miners from being struck, pinned or crushed by CMMs(3). Currently, MSHA-approved PDSs, installed on CMMs, are based on the principle of magnetic flux density (B-field) (4,5). The system generates a magnetic field around a CMM and determines the relative distance a miner is from the CMM based on a detected magnetic flux density. A PDS typically consists of multiple magnetic field generators mounted at different places around the CMM, and personal alarm devices (PADs), which are worn by the miners to detect the magnetic flux density. When a miner, wearing a PAD, gets closer to the machine, the PAD detects a stronger magnetic field from the generators and detects a weaker magnetic field when a miner moves away from the machine. The magnetic field generators installed on CMMs typically produce modulated magnetic wave signals at frequencies between 10 kHz and 120 kHz. The magnetic fields are measured by three small magnetic coil antennas mounted on orthogonal axes inside of the PAD worn by the miner. According to Faraday’s Law, the changing magnetic field induces a voltage in each coil antenna, and the voltage values are transmitted from the PAD back to a controller on the CMM wirelessly, typically at a frequency between 400 MHz and 2.5 GHz. These values are then used to determine the distance between the miner and the generators of the machine. Typically this information is used to determine when a miner wearing a PAD is in a warning zone or stop zone which would trigger different alarms and actions such as slowing the machine down or stopping it."

Jan 1, 2017

By Laszlo Kadar, J. D. Lavers

"In the continuous casting of aluminum killed steel, the tundish nozzle often experiences clogging problems. Water model studies have shown that the clogging problem is dependent on the flow pattern in the nozzle entry region. In particular, the flow can separate at the entrance to the nozzle, leading to the development of a recirculation region. Although a nozzle can be designed such that no recirculation develops, even a small misalignment from the vertical positioning of the nozzle may render the design ineffective.To reduce the possibility of nozzle clogging, the recirculation zone must be reduced or eliminated. This may be achieved by moving the fluid downwards or raising the turbulence level in the separation region. In the case of a tundish nozzle, it is proposed that this can be achieved by using electromagnetic forces.To generate the required electromagnetic force, two systems are considered. The first is based on injecting a DC current; the second by using electromagnetic induction. Both methods are described in this paper. Order of magnitude calculations are provided to illustrate that both methods are essentially feasible. The performance of each method in terms of modifying the turbulent flow characteristics in the nozzle entry region is then examined using a numerical model. It is shown that both methods can greatly reduce the recirculation zone. A cylindrical nozzle was chosen for the model studies since it represents a worst case situation.On the basis of the model studies, it can be concluded that whereas both of the proposed methods have the potential to reduce the troublesome recirculation zone, the induction method appears to be simpler in terms of practical implementation."

Jan 1, 1999