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By P. Condori, G. Rech, J. Winnett

"Palabora Mining Copper has a unique ore body composition which unlike other copper ore bodies has three main components in significant proportions; these are copper bearing ore, magnetite and dolerite. The high content of dolerite, a hard barren material, creates a high proportion of pebbles which normally are recycled back to the mill. This action increases the mill bearing pressure and power progressively until corrective actions are taken.A logical action to solve the pebbles generation would be to incorporate a pebble crusher. This in fact was done however two fundamental issues were encountered; the high content of magnetite and existence of a cyclone classification section. Due to the high content of magnetite, metal detectors have not been able to work efficiently to separate tramp metal which causes damage to the pebble crushers. The existence of cyclones in the circuit had a detrimental effect on the final product when the pebbles crusher was online producing coarse sandy material.Due to the difficulties in treating pebbles via conventional procedures and the unique Palabora ore composition and characteristics, sorting technology was investigated at laboratory and pilot scale. It was found that a combination of optical and electromagnetic sorting could efficiently separate dolerite from the copper bearing and magnetite ores.This paper reports the findings of the laboratory and pilot scale work performed and discusses the additional benefits to the circuit."

Jan 1, 2012

By A. Bascetin

The mining industry in Turkey has been developing in the last 10 years. Mine wastes and tailings have thus been increasing, depending on the rising production rates. There are many problems related to accidents that occur in tailings damps. In this study, the applicability of the surface paste disposal (SPD) method for a Pb-Zn mine in western Turkey was examined. Density was 3.084 and specific surface area was 0.899 m2/g. The mill tailings have very low plasticity and show characteristics of clays and silts in terms of the Unified Soil Classification System. The particle size distribution of the tailings was 39.2% particles finer than 20 µm. The results of this study showed that the physical and chemical properties of mill tailings make them suitable for SPD.

Aug 1, 2013

By Szilvia Szabo, Jozsef Paulovics, Ljudmilla Bokanyi

"Waste recycling is one of the most important challenges of the XXI century. The recycling of wastes is closely related to and bases on the mineral processing. Many mineral processing techniques and equipment are applied in this field. The principles of the characterisation of wastes and design of technologies is rather similar to the classic mineral processing. Nevertheless, the diversity of the wastes and their complex composition and properties, as well as their environmental impact requires a special approach.Solar elements have sandwich structure of glass substrate and cover, as well as a very thin semiconductor layer. CdTe semi-conductor can be recycled by flotation. Within the RESOLVED (LIFE European Framework) R&D project on the recycling of solar elements the surface properties of pure CdTe semiconductor and pure glass were investigated by the measurements of zeta-potential using Zeta PALS Brookhaven instrument at University of Miskolc. Applied surfactants were: potassium ethyl xanthate; the anionic oxhydryl Aero Promoter 825 or Flotinor SM 35; the cationic Armoflote 43 or Armoflote 64, as well as Hostaflot LET (dithiophosphoric acid diethyl ester) and Hostaflot M91 (mercaptobenothiazole). The tested electrolyte was sodium-silicate. Zeta-measurements were carried out in full pH-range. Interfacial interactions were detected and interpreted. The basic results were verified by the flotation kinetic tests.Finally, the flotation technological experiments were carried out at a semi-technical scale using the real obsolete solar elements. The particle size at the liberation degree of 98% was as fine as below 5 µm. A special flotation cell providing the generation and distribution of very fine air bubbles was built. The pre-concentrate for the manufacturing of the test solar module was performed and transported to the BAM Institute (Berlin), the principal co-ordinator of the Project, and then further to the First Solar (USA) where a new panel was manufactured using recycled semi-conductor."

Jan 1, 2016

By J. Cui, Z. Meng, W. Zhao

"The decomposition of rare earth concentrates containing bastnasite and monazite by alkali solutions has been investigated. A slurry of the rare earth concentrate and the alkali solutions was calcined at different temperatures. The impacts of calcination temperature on the decomposition of rare earth minerals, the oxidation of cerium, the deportment of fluorine and phosphorous, and the adaptability of the method to the different grades of rare earth concentrate were all studied. A possible technique for comprehensive recovery is proposed in which the chemical elements such as rare earth, fluorine, phosphorus, calcium, iron and thorium could be recycled or recovered. INTRODUCTIONThe liquid alkali decomposition method is an important technique for the decomposition of mixed rare earth concentrates. The technique is relatively clean compared with the sulfuric acid roasting method. However, its operation is intermittent rather than continuous. The two-step solid-liquid reaction and the subsequent water washing make it not very suitable for mass production and application. An important reason for the disadvantage is that an additional process of ""calcium removal by acid leaching"" is needed for the technique. The content of calcium in Baotou rare earth concentrates is usually 6-12%. The requirement of the current technique is that the content of calcium should be reduced to about 0.2% after the calcium removal process. Otherwise, the decomposition and leaching of rare earth will be affected. Therefore, calcium removal by acid leaching is a necessity before the alkali decomposition process is carried out. Research on different alkali decomposition techniques has been conducted with prior calcium removal by acid leaching (Xu, 1995; Yu, 1993; Han, Li, Chang, Liu & Xu, 1985). There have been some investigations of direct decomposition of the bastnasite (Feng, Pan & Li, 1998; Zhao, Zhang, Yang & Liu, 2002)and monazite (Sun, Li, Li, Su, Zhao & Liu, 1998; Zhou, 2005) by alkali-liquid, however, all studies were carried out in solid-liquid reaction system, and continuous calcination studies have not been reported.This paper investigates the process of direct decomposition of Baotou rare earth concentrates by continuous calcination with concentrated alkali. Using the rotary tubular electric furnace, the mixture of rare earth concentrate and concentrated alkali solution were decomposed continuously. Satisfactory decomposition results were achieved. A method for clean processing and comprehensive resource recovery from Baotou rare earth concentrates is proposed."

Jan 1, 2012

By G. Anger, J. Enser, H. Antrekowitsch, S. Koch

Homogeneous chemical composition and microstructure are always necessary, but not always attained in practice. As-cast aluminium alloys tend to have a segregation microstructure. Features of the cast structure, which affect subsequent processing or properties, can be altered by the homogenization. The main task of the Department of Nonferrous Metallurgy was to investigate the effect of homogenization treatment on precipitation hardening of aluminium alloys 6061 and 6082. The effect of the solution heat treatment (SHT) temperature on the mechanical properties was also analyzed. The homogenized and non-homogenized rolling slabs were produced according to the usual conditions and methods. The metallographic investigations were carried out on the as-cast samples, after homogenization, after the hot and the cold rolling mill, and after natural and artificial ageing. Then, Brinell hardness measurements and tensile tests were conducted on both alloys in order to examine the influence of the homogenization.

Jan 1, 2006

By S. Kwon, J. W. Wilson

"In salt and potash mines, the time-dependent deformation mechanism should be clearly understood based on in situ measurements to predict the performance of a mining design. In this study, in situ deformation measurements from the Waste Isolation Pilot Plant (WIPP) and other salt and potash mines were used to determine the transition time from the primary to the secondary creep stage and to investigate the influence of adjacent excavations such as a nearby tunnel excavation, panel excavation and/or pillar extraction on rock deformation. IntroductionThe deformational behaviour of underground excavations in salt and potash mines is complex due to the time-dependency of the rocks. When the material properties are determined from laboratory tests, they should be carefully applied to in situ conditions, because in situ conditions are completely different from laboratory conditions. For instance, in situ deformation measurements show that the deformation rate decreases with time similar to those observed in the laboratory during the early stages. However, the rapid decrease of deformation rate does not come from the microscopic strain hardening effect observed in laboratory tests, but mainly from stress relief around the opening after its excavation (Baar, 1977). It is, therefore, recommended to undertake in situ measurements and use them to understand the deformation mechanism.Even though in situ measurements are widely accepted as important information for understanding the deformation mechanism of salt and potash (Barr, 1971; Kovari and Amstad, 1993), not many publications have focused on the fundamentals of data measurement, the application of the measured data, and the development of data analysis techniques. Recently, several new techniques for better understanding the deformation mechanism of rock salt have been developed that are based on in situ measurements. Kwon and Miller (1995) developed a new technique for describing the actual deformational behaviour of an underground excavation in rock salt. The migration of “zero strain boundary,” which represents a no movement boundary around an underground excavation, could be calculated by the technique developed by Kwon and Miller (1996). Kwon and Wilson (1997, 1998) applied neural network techniques to in situ deformation measurements to predict the deformational behaviour of the underground excavations at the Waste Isolation Pilot Plant (WIPP) located in the United States.In this study, in situ deformation measurementsfrom the WIPP site and other salt and potash mines in the United States were extensively analyzed to understand the deformation mechanism of the underground excavations in the rock mass."

Jan 1, 2002

By G. Gauvin

Life span of aluminum smelting electrolysis cells can reach up to 3000 days. During this period, cathode blocks go under various physical and chemical changes that could result in an increase of electrical resistivity. The increase may be due to carbon migration from the cast iron to the steel bars, gap evolution between the cathode block and the cast iron, cathode cracking, etc. This paper focuses however only on the collector steel bar electrical resistivity evolution. To reveal the main phenomena responsible for the electrical resistivity increase, chemical analysis, metallographic and electrical resistivity tests were conducted on two steels bars picked from two Hall-Héroult cells after autopsies. Cathode voltage drop and temperature were measured using electrically insulated internal probes and thermocouples on 16 samples from each steel bar. Electrical resistivity can reach up to 1.21µO-m for a steel bar aged 2505 days compare to 0.142µO-m for steel AISI 1008 at room temperature.

Jan 1, 2011

By Neda Zangeneh

Production efficiency from low permeability gas shales require techniques to optimize hydraulic fracture completions. One completion strategy involves the simultaneous or near simultaneous hydraulic fracturing of multiple horizontal wells to maximize the fracture network area and stimulated reservoir volume. However, changes to the in-situ stress field caused by an earlier hydrofrac on subsequent hydraulic fractures are not accounted for in traditional hydrofrac design calculations. Presented here are the results from a set of transient, coupled hydro-mechanical simulations of a rock mass containing two wellbores using the discontinuum-based distinct-element method. The results demonstrate the influence of stress-shadows generated by a hydraulic fracture on the development of subsequent hydrofracs from an adjacent well. It is shown here that these interactions have the potential to change the size and effectiveness of the hydraulic fracture stimulation by changing the extent of the hydraulic fracture around the secondary well.

Jun 1, 2012

By Th. Hassel

The application of magnesium as an absorbable biomaterial demanded the consideration of the alloy composition, the mechanical properties and the corrosion a special adapted material development in terms of the human biological system. Magnesium for technical applications mostly comprised alloying elements up to 10 wt%. Thereby often metals (e.g. rare earth and aluminum) with high toxic potentials are used to optimize the mechanical properties. To minimize toxic reactions during the degradation of a absorbable magnesium alloy, the Mg-Ca system is being selected and investigated because both elements belong to the mineral nutrients. Rods and small tubes are produced by extrusion of gravity die casting billets (Ca-content 0.4 to 4.0wt%). The positive grain fining influence of calcium and its improvement of the corrosion behavior are additional advantages. The microstructure, the mechanical properties and the corrosion attitude are investigated. The results show that an optimal composition of micro alloyed Mg-Ca and ideally processing parameters lead to 16% strain and a tensile strength up to 185MPa. Electrochemical investigations and measurements of the hydrogen production demonstrate the influence of the Ca-content to the corrosion behavior of the investigated alloys.

Jan 1, 2006

By P. Chu, J. A. Finch, R. Li

"Bubble size plays a key role in flotation. In this paper, we examine the possibility of using passive acoustic sending to determine bubble size. Software was developed based on Short Time Fourier Transformation (STFT) to analyze the frequency of the acoustic signal emitted from the bubble formation event. Bubble size was determined from the Minnaert frequency. The acoustic-determined bubble size responded to reagent dosage, but was less sensitive than that given by imaging. The constraints of the current acoustic approach are discussed.INTRODUCTIONBubble size is an important factor affecting flotation performance. It determines the maximum available surface area for collecting and transporting mineral particles. Of interest for process control (Gorain, Franzidis, & Manlapig, 1995), it can be determined by several techniques, such as image analysis (Grau & Heiskanen, 2002; Hernandez-Aguilar, Gomez, & Finch, 2002); conductivity (Barigou & Greaves, 1992); drift flux analysis using gas rate and gas holdup measurements (Banisi & Finch, 1994); and optical sensors (Randall, Goodall, Fairlamb, Dold, & Connor, 1989). However, all these techniques have drawbacks.Acoustic analysis of the oscillatory behaviour of bubbles to extract bubble size is another possibility (Leighton & Walton, 1987; Pandit, Varley, Thorpe, & Davidson, 1992; Al-Masry, Ali, & Aqeel, 2005; Manasseh & Ooi, 2009; Leighton & White, 2012; Spencer et al., 2012). The fundamental basis is the work of Minnaert (1933) who first correlated the bubble size with its natural frequency, Equation 1:"

Jan 1, 2016

By T. Loos

The Norddeutsche Affinerie operates an Outokumpu-Flash-Furnace as a smelting unit. The pyrometallurgical slag cleaning process is based on the slag reduction and settling in the electric furnace. Since 1972 when the slag cleaning furnace was built the throughput could be increased fourfold. However, an extensive optimisation effort is required in order to keep the copper loss low. A parameter study with a neuronal network model based on real process data was conducted to identify parameters impacting on the copper loss in the slag. It could be demonstrated that the main parameters responsible for copper loss in the final slag are fixed parameters of the flash furnace. For a better understanding of the copper loss in the electric furnace microscopic analyses of the slag structure and viscosity measurements were performed. Based on these results the reduction and settling of the copper containing droplets could be increased in both pilot plant studies and industrial scale. 4

Jan 1, 2007

By B. Burke

Magnesium and its alloys are attractive materials for use in automotive and aerospace applications because of the low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. The present paper reviews the efforts to improve the attractiveness of magnesium through non-traditional processing, and presents preliminary results of current work on producing magnesium alloys via powder metallurgy P/M. P/M can be used to alleviate the formability problem through near-net-shape processing, and also allows unique chemical compositions that can lead to new alloys with novel properties. The feasibility of producing magnesium powder metallurgy products utilizing the industrially dominant process of mixed powder blending, uniaxial die compaction and controlled atmosphere sintering was investigated. An alloy composition based on the commercial Mg alloy AZ31 (3% Al, 1% Zn) was used to facilitate comparison to similar wrought products. The optimal processing conditions (compaction pressure, sintering time and temperature, and quenching temperature) were found to maximize sintered density and mechanical properties.

Jan 1, 2007

By Kazutoshi Haga, Batnasan Altansukh, Yasushi Takasaki, Mohd Yazid Bin Abdul Razak, Atsushi Shibayama

"In this study, the volatilization behaviour of arsenic (As) and antimony (Sb) from arsenicantimony bearing minerals such as tennantite (Cu12As4S13)/tetrahedrite (Cu12Sb4S13) in copper ore was investigated using a roasting process. Specifically, the thermal decomposition of tennantite and the arsenic volatilization were investigated under nitrogen and air atmosphere. The roasting experiments were performed at temperatures ranging from 500 to 1,200oC and different retention times using a laboratory electric furnace. The results indicated that over 95% volatilization was achieved at 700oC. On the other hand, when the temperature increased to 1,200oC, volatilization rate of Sb reached to 90%. Therefore, volatilization of Sb requires high temperature compared to As. It suggests that As and Sb can be separated using temperature difference. Selective removal of As is possible at 700oC, subsequently Sb can be recovered as a volatilized product by increasing the temperature to 1,200oC. Meanwhile, volatilization of Cu and Fe was not observed on these conditions. The content of As and Sb in the residues obtained from roasting at 700 and 1,200oC was less than 0.3 and 0.75 mass%, respectively. The Cu content in solid residue at 1,200oC increased to 34 mass%. The clean copper concentrate with lower amounts of arsenic and antimony was obtained from the process. INTRODUCTIONRecently, arsenic (As) and antimony (Sb) contents in copper (Cu) concentrates are increasing year by year. Arsenic and antimony are present with Cu minerals such as enargite (Cu3AsS4), tennantite (Cu12As4S13) and tetrahedrite (Cu12Sb4S13) that associate with copper sulfides [chalcopyrite (CuFeS2) and bornite (Cu5FeS4)]. They are normally concentrated by flotation and treated in copper smelters. However, treatment of copper concentrates containing high amounts of arsenic and antimony by a smelting process is difficult due to environmental implications of toxic arsenic and antimony. As demand for copper continues to grow, the need to source copper from several types of resources including those that contain high levels of As/Sb becomes necessary. Therefore, a novel processes for the treatment of As/Sb bearing Cu concentrates are required. Reviews on copper resources such as enargite, tennantite and tetrahedrite containing high amounts of arsenic and antimony are covered widely in literatures by many researchers (Padilla et al., 1998; Welham, 2001; Vinals et al., 2003; Guo & Yen, 2005; Balaž & Achimovicova, 2006a; Filippou et al., 2007; Mihajlovic et al., 2007; Lattanzi et al., 2008)."

Jan 1, 2016

By Y. Feng

Perovskite structured oxide 15% Y-doped BaCeO3 (BCY15) has been evaluated for use as proton conducting electrolyte in SOFC with propane as the fuel and Pt as both electrodes. Under the fuel cell conditions, BCY15 exhibited high proton conductivity and good cell performances. Propylene was detected as product at the anode outlet, and the product distribution suggests that propane dehydrogenation underwent competition with cracking to lighter hydrocarbons. Stability during cell performance tests showed that there was no obvious degradation for BCY15 electrolyte during operation of C3H8-O2 fuel cell.

Jan 1, 2005

By E. Ghali, C. Su, G. Houlachi

"The influence of lead ions on zinc electrowinning process was investigated by means of electrochemical noise measurements (ENMs) and cyclic voltammetry in conjunction with scanning electron microscopy and X-ray diffraction. All electrochemical experiments were performed in sulphuric acid electrolyte containing different lead ion concentrations as impurity. Lead was added in six trace levels between 0.05–0.8 mg/L in the bath. The lead content of the zinc deposits was dependent on the introduced lead concentrations. The overpotential associated with zinc electrodeposition shifted to higher values with the increase of lead concentration in the solution. An appropriate correlation was found between the different concentrations of lead in the electrolyte and the morphology of zinc deposit by ENM. The results showed that the increase of lead ion concentrations is generally accompanied with the decrease of skew and increase of kurtosis values that could be related to the morphology of zinc deposit. Effectively, the morphology changes from well-defined hexagonal platelets to large hexagonal, layered platelets and finally to non-symmetric refined crystalline structure, respectively.INTRODUCTION In commercial zinc electrowinning, zinc oxide is leached from the roasted calcine with an aqueous acid sulfate electrolyte. Then the zinc-rich solution is purified and transferred into an electrolytic cell. During electrolysis, zinc is deposited on aluminum cathode where lead-silver or pure lead is served as anode. Electrodeposition of zinc could be influenced by several parameters such as bath acidity, temperature, current density, the nature and concentration of impurities as well as additives in electrolyte. Metallic impurities play a complex role during zinc electrowinning and they can adversely"

Jan 1, 2016

By Peter Mitschke, Friedrich Rosenstock, Heinrich Meiler

"The development of the Centrifugal Mill jointly by Chamber of Mines (Johannesburg) and LURGI GMBH (Frankfurt) had been described by L. Kitschen e.al. during the 14th IMPC at Toronto in October 1982. Further investigations, using a 55 kW semi-industrial mill, installed at LURGI's Research Laboratories, were concentrated on efficiency and wear in grinding.The test results showed, that efficiency increases when increasing the ball load between 60 and 80 % by volume. Furthermore, the efficiency is increased by speeding up the mill, thus increasing the centrifugal force to up to 14 times the force of gravity. Applying these findings to grinding of a Canadian iron ore spiral concentrate, a saving in grinding power of 30 % was experienced, when comparing with ordinary wet ball milling.Investigations of several shapes of the grinding chamber cross section and linings and several types of materials showed, that no increase of liner or ball wear will occur compared to conventional ball mills when choosing suitable lining patterns. 1. DEVELOPMENT OF THE CENTRIPUGAL MILLThe centrifugal mill was developed with the aim of finding a grinding unit that can operate at a higher power concentration than the conventional tumbling mills.LURGI felt the necessity for such a mill in connection with a hydrometallurgical process developed at the beginning of the seventies, which incorporated an activating grinding step as one of the essential process features. At that time, the Chamber of Mines in Johannesburg was investigating possibilities of underground wet grinding and preconcentration of gold ores aiming at a decrease of mining costs by reducing the quantities, especially for mines operating at depths up to 3600 m, by changing over from rope hoisting to hydraulic transportation systems. After the Chamber of Mines had initiated the development work on its own, in 1974 a cooperation between the two organisations was started."

Jan 1, 1985

By I. Silin, M. Stapelmann, H. Wotruba, K. M. Hahn, C. Gerold, J. Katzmarzyk

New deposits are often characterized as low-grade and complex ore bodies. To date, processing of fine grained ore deposits implies complex processing routes with high energy consumption. For that reason, the investigation of dry grinding, e.g. with vertical roller mills (VRM), is an approach to save energy reserves. It is already proven that dry grinding can influence subsequent processing steps. In terms of flotation, the surface characteristics of the minerals are crucial for a successful flotation process, e.g. the sufficient adhesion of mineral particles and air bubbles. Wet grinding results in different surface properties of the product entering the conditioning stage than dry grinding, which has direct influences on the subsequent flotation process. To investigate the consequences for flotation, processing of a copper sulfide ore containing chalcopyrite and bornite was investigated, including grinding and rougher flotation. The effects of wet tumbling mill and dry VRM grinding on the degree of liberation of valuable minerals are characterized using mineral liberation analysis by scanning electron microscopy. The obtained flotation results, as well as the recorded flotation parameters such as dissolved oxygen, oxidation reduction potential and conductivity are presented and discussed. INTRODUCTION Copper production is mainly connected to porphyry copper deposits as main source for copper sulfides such as chalcopyrite and bornite. State-of-the-art processing of these deposits is already established worldwide for decades, combining crushing, fine grinding and subsequent flotation with rougher, cleaner and scavenger stages (del Villar, Desbiens, & Maldonado, Bouchard, 2010). While the demand for copper is increasing, copper grades of the deposits are decreasing and the remaining ore bodies have more complex mineralogy and finer particle size distribution. This implies processing routes with high water and – due to the liberation of fine grained valuable minerals – high energy consumption by fine grinding. One of the main energy consumers in processing plants is the grinding section, which accounts for more than 50% of the energy consumption in processing plants and even 4% of the worldwide energy consumption (Jeswiet, & Szekeres, 2016). Therefore, dry fine grinding alternatives are applied to enhance the overall energy consumption of mineral processing plants: high pressure grinding rolls (HPGR) and vertical roller mills (VRM).

Jan 1, 2019

By S. Balideh

A good understanding of the behavior of rock helps us to make more informed decisions regarding geo-structures. Engineers need accurate equations to calculate the strength and deformation of rock before and after failure. Previous studies explain the failure of rock to ultimate strength, and laboratory tests adequately determine the ultimate strength and deformation modulus of rock. However, there are few comprehensive equations to determine the post-failure strength and deformation of rock. Previous work shows that the post-failure behavior of rock depends on the behavior of the broken rock particles after failure. The following question is then posed: How can the post-failure behavior of rock be determined by the behavior of broken rock particles? In order to answer the question, this study pursues three objectives: (i) to explain the behavior of broken rock at low confining pressure; (ii) to estimate the behavior of broken rock via the extrapolation of scaled laboratory testing; and to suggest a procedure (iii) to outline the post-failure behavior of a rock mass at low confining pressure commensurate with the behavior of broken rock in a rock mass.

Aug 1, 2013

By Kremena Dedelyanova

The paper presents research of mechanism for the creation of air bubbles in vibratory a column flotation machine. Factors are discussed that influence the increase in the duration of the bubble in the area of contact with the mineral particles. Formulas are derived for the parameter effect of vibrations, applicable to the design of flotation machine. The collision efficiency of the bubbles in a vibratory column flotation machine is determined.

Aug 1, 2013

By T. Senga, T. Namihira, S. Terada, S. Owada

"Electrical disintegration (ED) has been well known as a good comminution method to improve liberation of compositional phases because it was reported that electron avalanche could occur preferentially at phase boundary. But the detailed mechanism of the ED has been still not known. This paper describes the results of ED experiments using synthetic binary sample, copper/resin, under the conditions of various distance between electrodes, and discusses the energy distribution in the three kinds of phenomena in the ED process, which are(1) streamer progression in water, (2) electron avalanche in water, and (3) electron avalanche in solid sample, by measuring current and voltage with elapsed time. Then, it has been found that the energy distribution in the phenomenon (1) is quite low and that the distribution in the phenomenon(2) had a considerably large compared with that in the(3), which indicates that the shockwave generated in water could contribute much to the sample breakage.INTRODUCTIONElectrical disintegration (ED) has been well known as a specific comminution technology which enhanced selective breakage at phase boundary and lead to a good liberation among compositional phases1-6),but the detailed mechanism has not been clarified yet. This study describes energy distribution among the phenomena in the ED process by using a synthetic binary sample, copper/resin, the phenomena of which are (1) streamer progression in water, (2) electron avalanche and shockwave generation in water and (3) electron avalanche in solid sample usually at phase boundary. The energy distribution could be calculated from ED experiments and from voltage-current changes between electrodes as a function of elapsed time.SAMPLE AND EXPERIMENTALSampleThe sample used in this paper was a synthetic binary solid of copper/resin as shown in Figure1.Cut and polished pure copper lump was put into silicone mold and melted epoxy resin was poured into it and cooled, then, finally the binary sample was polished and molded in the form of 10 mm * 10 mm * 10 mm."

Jan 1, 2017