Kg Of Copper Research Articles

Modelling of different measures for improving removal in a stormwater pond

The effect of retrofitting an existing pond on removal efficiency and hydraulic performance was modelled using the commercial software Mike21 and compartmental modelling. The Mike21 model had previously been calibrated on the studied pond. Installation of baffles, the addition of culverts under a causeway and removal of an existing island were all studied as possible improvement measures in the pond. The subsequent effect on hydraulic performance and removal of suspended solids was then evaluated. Copper, cadmium, BOD, nitrogen and phosphorus removal were also investigated for that specific improvement measure showing the best results. Outcomes of this study reveal that all measures increase the removal efficiency of suspended solids. The hydraulic efficiency is improved for all cases, except for the case where the island is removed. Compartmental modelling was also used to evaluate hydraulic performance and facilitated a better understanding of the way each of the different measures affected the flow pattern and performance. It was concluded that the installation of baffles is the best of the studied measures resulting in a reduction in the annual load on the receiving lake by approximately 8,000 kg of suspended solids (25% reduction of the annual load), 2 kg of copper (10% reduction of the annual load) and 600 kg of BOD (10% reduction of the annual load).

Impact of 7-TeV∕c large hadron collider proton beam on a copper target

The large hadron collider (LHC) will allow for collision between two 7TeV∕c proton beams, each comprising 2808 bunches with 1.1×1011 protons per bunch, traveling in opposite direction. The bunch length is 0.5ns and two neighboring bunches are separated by 25ns so that the duration of the entire beam is about 89μs. The beam power profile in the transverse direction is a Gaussian with a standard deviation of 0.2mm. The energy stored in each beam is about 350MJ that is sufficient to melt 500kg of copper. In case of a failure in the machine protection systems, the entire beam could impact directly onto an accelerator equipment. A first estimate of the scale of damage resulting from such a failure has been assessed for a solid copper target hit by the beam by carrying out three-dimensional energy deposition calculations and two-dimensional numerical simulations of the hydrodynamic and thermodynamic response of the target. This work has shown that the penetration depth of the LHC protons will be between 10 and 40m in solid copper. These calculations show that material conditions obtained in the target are similar to those planned for beam impact at dedicated accelerators designed to study the physics of high-energy-density states of matter, for example, the Facility for Antiprotons and Ion Research at the Gesellschaft für Schwerionenforschung, Darmstadt [W. F. Henning, Nucl. Instrum Methods Phys. Res. B 214, 211 (2004)].

Recovery of valuable metals from electronic and galvanic industrial wastes by leaching and electrowinning

In the present paper, a study on laboratory scale to perform a treatment for valuable metals recovery from electronic and galvanic industrial wastes, is reported. The characterisation of the waste, performed by XRD, SEM, EDX and chemical analysis, showed a high metals content in the sludge, such as Cu, Ni, Mn, Pb, Sn, W. A leaching process, coupled by electrowinning, is then proposed in order to reduce the volume of the waste material and to recover selectively valuable metals, such as Cu and Ni. During the leaching step, carried out by using H 2SO 4, several factors were investigated (acid concentration, temperature and time of treatment). The leached liquor has been successfully treated with an electrowinning process, to recover copper and nickel. The copper and nickel depositions, were performed in acid and alkaline conditions, respectively. The Faraday yield was of about 95%. The energy consumption was 2.13 and 4.43 kWh per kg of copper and nickel recovered, respectively. At the end of the process, about 94–99% of the initial content of Cu and Ni was recovered at the cathode. The experimental results obtained, showed the technical feasibility of the process.

The contemporary European copper cycle: 1 year stocks and flows

Substance flow cycles can provide a picture of resource uses and losses through a geographic region, allowing us to evaluate regional resource management and estimate gross environmental impacts. This paper traces the flow of copper as it enters and leaves the European economy over 1 year and provides the numerical accounting of copper flows that are further analyzed in a companion paper in this issue. We examine the major flows of copper from ore, as it is extracted from the earth, transformed into products, and discarded or recycled. A regional material flow model was developed to estimate patterns of copper use in the early 1990s in select European countries. Successive mass balance calculations were used to determine copper flows, including the amount of metal that enters use in society and is deposited in waste repositories. A database that records temporal and spatial boundary conditions and data quality was developed for continental substance flow analysis. The majority of copper is mined, smelted, and refined outside of Europe. Across the life cycle, a net total of 1900 Gg/year of copper is imported into Europe. About 40% of cathode copper produced within the system is made from old and new scrap. It is estimated that approximately 8 kg of copper per person enters use in society, largely in infrastructure, buildings, industry, and private households. The majority of copper in finished products is contained in pure form (70%), the remainder in alloy form. The waste management system in Europe recycles about 60% of the copper from waste. The copper discard flow from post-consumer waste is roughly five times higher than that from copper production waste. This ratio would decrease if we consider production wastes generated outside of the European system boundary. The net addition of copper to the stock in society in the system is about 6 kg/person. Given the in-service lifetime of the applications of copper identified in this model, most of the copper processed during the last few decades still resides in society, mostly in non-dissipative uses.

The significance of the floodplain to the cycling of metals in the river Derwent Catchment, U.K.

This study investigates the cycling of heavy metals in a contaminated river catchment, and focuses on the important role of floodplains in the storage of fine suspended sediment. This sediment may be reworked by the contemporary river channel and the metals released could cause secondary pollution of the river. Sediment cores were collected across an extensive reach of the floodplain of the River Derwent, U.K., and sectioned at 5 cm increments to about 60 cm. Analyses of the metal content of the sediments showed a uniform addition of metals to the floodplain surface over time, although spatially there were positions on the floodplain with high concentrations of lead, zinc and cadmium. The contemporary sediments were distinguished by the presence of 137Cs, and they contained similar metal concentrations to sediments deposited during the period of active mining within the catchment. By combining information on rates of sedimentation derived from the analysis of 137Cs with average metal concentrations, the contemporary annual supply of metals to the 0.20 km 2 study reach was estimated as 360 kg of lead, 100 kg of zinc, 10 kg of copper and 2 kg of cadmium each year. These may also be expressed as loadings of metal to the floodplain surface of 1800 mg Pb, 500 mg Zn, 50 mg Cu and 10 mg Cd m −2 year −1, of which 266 mg Pb, 36 mg Zn, 5.2 mg Cu and 0.1 mg Cd m −2 year −1 was easily exchangeable and could be ‘bioavailable’.

New experimental limit on the stability of the electron.

A lower limit of 1.5\ifmmode\times\else\texttimes\fi{}${10}^{25}$ yr (68% C.L.) is reported for the mean life of the electron decay via the branch ${e}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}\ensuremath{\gamma}+${\ensuremath{\nu}}_{e}$. This is significantly longer than the best previously reported limit. Data were collected for 8850 h with an ultralow-background 135-${\mathrm{cm}}^{3}$ Ge detector located 1438 m underground. The electrons of primary interest are in the germanium crystal and in 102 kg of copper surrounding the detector. A projection of the ultimate limit on the half-life for this decay mode which would be attainable using this technique, under the most optimistic circumstances, is about 3 orders of magnitude higher.

A Chemical Cleaning Process for Nuclear Steam Generators

A chemical cleaning process for the dissolution of deposits containing iron and copper on steam generator tubes was developed. The process consists of sequences of copper and iron removal steps.The solvent for the iron removal process is a mixture of ethylene dinitrilo tetra acetic acid, citric acid, hydrazine, and a corrosion inhibitor and is applied at 90 to 95°C. The pH of the solvent is adjusted with ammonia. The composition of the solvent was optimized to balance the rate of dissolution of the deposits and the rate of corrosion of steam generator materials.Copper is removed by sparging air through a strong ammonia solution at a temperature between 25 and 65°C.The steam generator at the Nuclear Power Demonstration Nuclear Generating Station was cleaned successfully using this process. Severe fouling of the steam generator had restricted the power output of the station to ~70% of its rated value of 25 MW(electric). About 500 kg of magnetite, 200 kg of copper, and 200 kg of other metals and anions were removed, using a total of six copper removal steps and four iron removal steps. The station has returned to full power operation and is continuing to operate at full power with 3 to 4 MW(electric) of excess capacity in the steam generator.

Refrigerator cools to 50 microkelvin

A double‐stage nuclear demagnetization refrigerator promises to allow experiments at temperatures an order of magnitude lower than previously available. The new cooling device can not only reach record low electronic temperatures of 50 microkelvins but can maintain these temperatures long enough in an apparatus large enough to cool samples within it. The apparatus was developed at the Kernforschungsanlage Julich in West Germany. Experimenters there have cooled about 2 kg of copper to an electronic temperature of 48 microkelvins and kept it below 60 microkelvins for more than two days. At the same time, in Japan, a group from the Institute for Solid State Physics at the University of Tokyo has reported equally low temperatures with a similar method but in a much smaller device.

Egyptian Lessons for Materials Management and Purchasing

The Egyptian empire obtained its gold from mines in Nubia and the Sudan and its copper from the Sinai peninsula. To obtain silver, however, the Egyptians had to fall back on foreign trade, particularly with the country of the Hittites. (The Hittite New Empire, 1400–1200 BC, included large parts of Asia Minor.) Inscriptions recording the gifts of Ramses III to the Gods also mention the gold, silver and copper received every year by the most important temples. These figures show that the three temples of Anion, Re and Ptah each received 52 kg of gold, 1060 kg of silver and 2510 kg of copper annually. From this we can draw conclusions not only about the powerful financial position of the temples but also about the level of metal imports from Asia. Early in the reign of Ramses III the Hittite empire was overrun by the Sea Peoples, threatening the normal exchange of Egyptian grain and gold for Anatolian silver. (Ramses III, 1198–1166 BC, was the second pharaoh of the twentieth dynasty.) The same applied to iron, which also came from Hittite territory. A most important aspect of this situation was the fact that the Bronze Age had come to an end about 1150 BC and that the Iron Age was dawning. Copper, the main constituent of Bronze, which was easily obtainable from the Sinai mines, was displaced by iron, which was not found in Egypt. The State abandoned its operation of the copper mines in the Sinai; the import of iron became of vital importance and that fact weakened the financial structure of the whole Egyptian state.

Application de l'electrode a poudre bipolaire au couplage de deux processus d'electrolyse

Plate powder electrodes made from compressed activated carbon, allow the coupling of two electrolytic processes. The powder electrode is bipolar. Two electrolysers with different processes work in series, actuated by the same current. The coupled processes are such that hydrogen is produced on the face of the electrode serving as cathode and oxygen on the face serving as anode: the gasses are not formed free but are absorbed by the active carbon and afterwards react to form water. Thus the electrode retains its capacity to absorb hydrogen and oxygen indefinitely. Results obtained by the method for the simultaneous production of zinc and chlorine, copper and chlorine and zinc, chlorine and sodium hydroxide, are described. In all cases, energy consumption per unit mass of electrolysis product is relatively small. Thus, at 32°C, the simultaneous production of 1 Kg of zinc from zinc sulphate and 1·08 Kg of chlorine from 10% hydrochloric acid requires 2·68 KWh, and that of 1 Kg of copper from the sulphate and 1·005 Kg of chlorine from 10% hydrochloric acid requires 1·60 KWh. Analytical data on the passage of ions through the powder electrode, and potentiometric measurements, show that current passes through the electrode partly through the carbon grains and partly through the solution in the intergranular pores. The presence of oxygen on anodic and hydrogen on cathodic carbon grains is suggested.

A Magnet and Cloud Chamber for Cosmic-Ray Studies

Details are given of the construction of an electromagnet, cloud chamber and accessory apparatus for use in cosmic-ray studies. The magnet has 9100 kg of steel, 1000 kg of copper, and has pole faces 30.5 cm diameter, normally used at an air-gap of 19.2 cm. The magnet is oil cooled and is usually operated at from 35 to 125 kw, the power being supplied by a motor-generator with variable field. Under these conditions the field increases from about 12,400 oersteds at the lower power to 16,000 oersteds at the higher power. The cloud chamber is of the diaphragm type, 30 cm diameter by 4.2 cm deep, and is filled with argon and ethyl alcohol vapor to 88 cm Hg pressure. The photographs are taken with the help of a 45° mirror placed against the front glass of the chamber. For illumination a Sperry carbon arc or a capillary mercury arc is used, the latter proving on the whole more satisfactory. With the lower magnetizing currents the temperature of the magnet and chamber can be maintained so close to that of the outside air that convection currents are small, and the tracks show little distortion. Errors in measuring the energy of cosmic-ray tracks are caused chiefly by distortions of the tracks. The probable error is 6 percent for a track of 109 ev, and about equal to the energy itself when this is 1.6×1010 ev.