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By Reuben John Mathew

"Oxygen evolution is the main anode reaction in industrial copper electrowinning. The oxygen bubbles do not conduct electricity, thus increasing the electrolyte resistance. The oxygen bubbles formed at the anode rise to the surface, occupying a larger volume of the electrolyte at the top of the cell than at the bottom. This oxygen bubble concentration gradient contributes to a gradient in electrolyte resistance and consequently a tendency toward uneven current distribution. This phenomenon increases the chance for uneven growth on the cathode and/or short-circuits, particularly on the lower portions of the cathode. This issue may be ameliorated by increasing the charge transfer resistance for oxygen evolution down the height of the anode. This concept was studied by solving the current distribution for a 2-D model of a copper electrowinning cell using COMSOL.IntroductionA copper electrowinning tankhouse aims to operate at the highest current density that will deposit on the cathode a layer of copper metal possessing the desired physical and chemical characteristics. The operating current density is directly related to the physical nature of the copper deposit on the cathode (Figure 1), limiting a copper electrowinning tankhouse to some operating current density that produces acceptable copper deposits.[!] The ratio of the operating current density to the limiting current density is typically around 0.3.[2] If the limiting current density for a cell could be raised, the operating current density could also be raised and thus result in savings in capital cost for a tankhouse. [3]The average operating current density in a copper electrowinning plant is 270A·m- 2 .[4] The value for average current density, however, obscures the fact that the face of a cathode does not experience this value equally. Indeed, the current density varies along the height of an electrode and is independent of the height of the electrode.[5] This phenomenon partly explains why the lower portions of a cathode tend to display a rougher copper deposit.In order to utilize a higher operating current density but still remain at 30% of the limiting current density, the limiting current density must be raised, but it is affected by the mass transfer regime at the electrodes. The mass transfer regime is currently poorest at the lower portions of the cathode and this is part of the reason for the tendency for poor cathode deposits to occur at the lower portion of the cathode.[6]"

Jan 1, 2012

By Heimo Thalhammer

During the refining of lead, copper or other metals the furnaces used in the process · often produce waste gases. This paper illustrates how these waste gases can be successfully treated and destroyed by CTP 2-bed or multi-bed compact systems, modified for the additional reduction of dioxins and furans. The CTP regenerative thermal oxidizer also destroys voes (organic compounds and odours) using ceramic blocks as a heat exchanging media. The raw gas is forced through the ceramic beds where it is heated up to the oxidation temperature level. The voes, dioxins and furans are destroyed in the combustion chamber, subsequently generating water, eo2 and heat. The hot purified gas heats up a second ceramic bed, which is used to preheat the raw gas after the valves have been switched. This process does not produce any secondary waste such as contaminated water, polluted air or any other products that have to be disposed of.

Jan 1, 2000

By Kuiting Wang, Jinshan Liu, Ninglei Sun, Aiguo Dong, Yeda Lu

"Eliminating the environmental threat caused by waste effluent containing magnesium sulfate derived from the process of nickel laterite sulfuric acid leaching and subsequent nickel precipitation is always a focus in the metallurgy field. A new flowsheet whose procedures include vaporization, crystallization, two stages precipitation of magnesium, causticizing treatment of filtrate and ammonia recycle was investigated. Both the details of the flowsheet and its application are described in this article. It is confirmed to be an effective and economical method to prevent the pollution by the waste effluent, simultaneity, a series of magnesium products recovered during the process own good economic returns.IntroductionSulfuric acid leaching is the conventional procedure of extraction valuable metals from ores in hydrometallurgy field. During the process of nickel laterite sulfuric acid leaching, several metals, including Ni, Co, Al Mn, Fe, Mg etc., migrate into the leachate in the form of soluble metal sulfate. After subsequent procedure of purification, precipitation of Ni and Co and neutralization, an enormous stream of waste effluent which contains a concentration of approx. 15-40g/L Mg is exhausted. Such solution containing magnesium sulfate is toxic, which causes diarrhea for both human and animals. On the other hand, large amount of sulfate acid was consumed during the process of leaching by the compound of Mg, which increases cost of a hydro nickel plant.In arid areas, the waste effluent mentioned above is treated via evaporate pond owning large acreage, which needs not only the appropriate meteorologic condition, but occupies much land. In coastal areas, it is directly discharged to the sea, which probably deteriorates ecological system of offshore strip. The most widespread method to treat with the waste effluent is neutralization by lime cream, the residues of which containing magnesium hydroxide and gypsum are transported to residues pool. Neutralization is a simple process, but it never recycles the Mg and sulfate anion into new application, meanwhile, the residues are potential threat to the environment."

Jan 1, 2012

By Keuncheol Choi, Yonghack Lee

"The new lead smelter based on the QSL technology was started operation from May 1992 at Onsan Refinery of Korea Zinc Co., Ltd. The smelter is designed to treat not only various types of lead concentrate but also secondary materials coming from the zinc plant without special pretreatment.Shortly after the start-up of the operation, it has demonstrated that the smelter have a capability to treat wide range of raw materials. Continuous modifications and improvements of the plant are still under way to increase the feed rate and also the ratio of secondary materials to the feed.In this paper, the operating experience and results of QSL smelter, especially the injection of gases and coal to the melt, will be presented with major operation parameters and data.INTRODUCTIONThe QSL lead smelter based on new injection technology was commissioned at the Korea Zinc's Onsan plant from May of 1992. After starting the operation, the QSL lead smelter faced various kinds of mechanical and metallurgical troubles. However, these were gradually worked out by the continuous improvements and efforts.At present, the QSL lead smelter is operated stably at the total feed rate of 57 tonnes per hour with an increased amount of secondary materials."

Jan 1, 1996

By Carlos Maurício. F. Vieira, Lázaro A. Rohen, Sérgio N. Monteiro, Rafael G. de Castro, Gustavo X. Borges, Maycon A. Gomes, Frederico M. Margem, Anna C. C. Neves

Economic and environmental benefits are motivating studies on natural fibers, especially lignocellulosic extracted from plants, have been studied to substitute synthetic fibers, such as glass fiber as reinforcement in polymer matrices. By contrast to synthetic fibers, natural fibers have the disadvantage of being heterogeneous in their dimensions specially the diameter. About the hemp fiber, little is known of their dimensional characteristics. The aim of the present work was to statistically characterize the distribution of the diameter of hemp fibers. Based on this characterization, diameter intervals were set and the dependence of the tensile strength of theses fibers with a corresponding diameter was analyzed by the Weibull method. The diameter was measured with precision using a profile projector. Tensile tests were conducted on each fiber obtain mechanical strength. The results interpreted by Weibull statistical showed a correlation between the resistances of the fiber to its diameter.

Jan 1, 2015

By Shenghui Guo, Dongbo Li, Lijun Liu, Chengdong He, Jinhui Peng, Libo Zhang

In present study, partially stabilized zirconia (PSZ) was prepared by CaO doped fused zirconia heated by microwave furnace at the temperature of 1450 oC and holding time of 120 min. The XRD results showed that untreated fused zirconia mainly consists of crystalline compounds of cubic ZrO2 phase; while the roasted one mainly is composed of crystalline compounds of cubic ZrO2 phase and monoclinic ZrO2 phase. It is shown through the optimization of structures of two phases that structure of cubic ZrO2 and monoclinic ZrO2 reject each other, revealing its difficulty in forming coinciding interface and linkage of two phases being of Ca atom. Introduction Due to advantages of zirconia, such as high melting point, chemistry inertia, low heat transmission and so on. Zirconia is always taken as megathermal refractory material[1]. However, in the heating and cooling processes of pure zirconium oxide, martensitic transformation will take place associated with greater shear force and volume change, which severely limits the industrial application of pure zirconia in some areas. Such as: Refractory materials, grinding materials and high temperature insulation materials[2]. Through adding a certain amount of MgO, CaO, or Y2O3 stabilizer, etc.[3,4], the zirconia can change into fully stabilized zirconia, which exists in cubic phase. But this high purity fully stabilized zirconia cracks easily because of thermal stress. Therefore, the thermal shock resistance variation is one of the most important quality indicators of zirconia-based materials. According to the heat treatment, the fully stabilized zirconia can be changed into the partially stabilized zirconia (PSZ)[5], which exists in cubic phase and monoclinic phase and has superior mechanical properties, such as anti-heat, low thermal conductivity, large coefficient of thermal expansion and stability, as well as good wear resistance[6].

Jan 1, 2011

By O. Chemezov, Yu Zaikov, A. Apisarov, A. Isakov

"Silicon deposits containing 99,9 wt.% of main component were obtained by SiO2 electrolysis from chloride-fluoride melts. The operating temperature was varied from 973 up to 1073 K. The conditions for obtaining crystalline fibrous micro- or nanodeposits were determined. The deposits were investigated by ESM methodIntroductionThere are large reserves of natural quartz of high purity in Russia. Processing of this raw material by electrolysis in molten salts produces silicon containing 99.9 weight percent of basic substance.[1]This method is less energy-consuming in comparison to existing methods for producing high purity silicon from gas phase.Another advantage of the electrolytic method for producing silicon from its oxide in molten salts is the possibility of production of high-purity silicon under air atmosphere. It dramatically reduces costs of the electrolytic cell construction, and the operating costs at electrolysis.On our opinion, the main advantage of the electrolytic production from SiO2 in molten salts is a unique opportunity to obtain micro-and nanostructures of silicon deposits. In particular, it is possible to obtain fibrous structures of silicon. The electrolytic method allows smoothly adjusting the thickness and length of silicon micro- and nano-wires by varying the cathode current density and temperature of the process."

Jan 1, 2012

By S. H. Castro

In 1997 Chile was the world's largest copper mine producer with around 3.4 million metric tomes of copper. Conventional technology (conminution-flotation- smelting-converting-electrorefining) for copper sulfide ores was used. For copper oxidized ores hydrometallurgical processes (heap leaching-solvent extraction- electrowinning) were employed. Consequently, the most important waste effluents include flotation tailings, gaseous emissions, smelter slags, acidic and alkaline wastewater, electrolytic sludges, solid residues from leaching, etc. The introduction of stricter environmental regulations are forcing the Chilean industry to minimise the generation of waste and promote cleaner production. Gas emissions such as SO2 and arsenic from smelters and process wastewater are the major problems at this stage. The environmental impact assessment of gas emissions in all six largest smelters namely Chuquicamata, Caletones, Potrenllos, Ventanas, Paipote and Chagres led to design a "decontamination plan." The implementation of this plan resulted in (i) the installation of sulfuric acid plants for SO2 abatement and (ii) the installation of electrostatic precipitators to remove arsenic oxides condensed from cooling gases. The aim of this paper is (i) to describe the type of waste associated to the various stages of the metallurgical processes and (ii) review the main abatement technologies used in medium and large size companies.

Jan 1, 1999

By Muhammad Abid, Kh. .. S. Karimov

"In this study, design and investigation of biogas digester consisting of methane tank with built-in solar collector to utilize solar energy for the heating of the slurry prepared from the dung and heat exchanger is designed, developed and tested. The digester was laboratory type and consists of cylindrical metallic tank of size of 0.5 m in diameter; 1 m in height and 200 liters in volume. The surface of the digester from outside was covered by thermo insulated material a glass wool, except of south side (in northern hemisphere). This side played the role of built-in collector and was blackened to increase absorption of solar irradiation and covered under 45o by glass. In the blackened side of the digester on the different heights it was installed metallic pipes for the inlet and outlet of the air, connected with heat exchanger installed inside of the digester. The heat exchanger was fixed in the level above of the inlet pipe. The horizontal plane reflector concentrates solar beams to blackened side of the digester. In the winter period, it was found that the retention time of this digester is shorter on 15% and produced biogas volume is larger on 20% with respect of ordinary biogas digester. This digester is used for the demonstrative purposes and as a teaching aid presently and base on the results it may be used for the construction of large volume digesters for use in the farms, especially located in the remote and mountain areas where the climate in the winter period is cold. Introduction At present many experts around the world have focused their efforts to energy crises because energy is one of the most important factors for the development of the society. It is known that consuming energy is proportional to quality or standard of life. There is a close relationship between energy consumption and the Gross National Product (GNP). It is obvious that for further development of the country additional sources of energy is required, which are cheap, safe and environmentally compatible with respect to the action on possible wastes. Utilization of renewable energy is one route to help in solving the above mentioned problems. In particular, biogas as a source of renewable energy is produced by biotechnology and used wide on residential scale [1]. The biogas was produced for the very first time in 1814 by Deivy from organic wastes. In 1900 production of biogas was started in Bombay (India) [2, 3]. Biogas consists of 55-70% methane (CH4) and around of 27-44% carbon dioxide (CO2) and less than 1% H2 and H2S. At present biogas is used widely in some countries for lighting, machines, and vehicles, generators, cooking and heating. Biogas generation is suitable for small to large scale operation and at present is realized in a number of developed and developing countries as USA, Hungary, China, India etc. Since 1990s biogas projects construction in China has developed steadily by the end of 1998, there were altogether 6.88 million household biogas digesters [4]. In Russia biogas digesters are used for processing of hard dung into biogas [5]. Over the last few years the very first biogas digesters were constructed in Tajikistan as well [6,7] and it was found that the digesters can work with sufficiently high efficiency in mountain areas as well ."

Jan 1, 2008

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from the University of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from theUniversity of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from theUniversity of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from the University of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from theUniversity of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

By Gary Kordosky

Equilibrium modifiers, first introduced into copper solvent extraction reagents in the late 1960?s, are widely used. The properties of various equilibrium modifiers with respect to copper extraction, selectivity, reagent stability and entrainment are discussed and some conclusions are drawn relating the structure of the modifier to the properties of the modifier. A new highly selective, low viscosity modifier is also introduced.

Jan 1, 2003

By A. Warczok

The heat transfer coefficient between liquid slags and solid surfaces is important for the design and operation of metallurgical reactors. An experimental technique developed for the purpose of measuring the heat transfer coefficient between liquid slags and solid metals is described. During the initial heating up of a Ni cylinder upon immersion in a liquid slag, a layer of frozen slag initially forms, then melts. The heat transfer coefficient measured during the initial rapid heat-up of the Ni cylinder, is approximately twice as high as the heat transfer coefficient measured during the final heat-up of the Ni cylinder subsequent of the liquidus temperature of the slag. The technique was tested in various melts i) NaNO3, ii) NaCl, iii) Na3AlF6 and iv) 2FeO*SiO2, giving consistent results. It was found that the heat transfer coefficient increases with increasing bath superheat and stirring. The heat transfer coefficient during the heating up following complete remelting of the frozen slag, is related to the slag superheat(AT) and the specific stirring energy(W) per kg of slag(E) as follows.

Jan 1, 1993

By Wenbo Luo, Kang Liu, Fusheng Mao, Jilai Xue, Jun Zhu, Chunlei Yang

Extracting alumina from coal fly ash (CFA) is of great interest for both environmental protection and recycling valuable alumina content. In this study, ultrasonic aided leaching process as an effective method was investigated to enhance extracting Al2O3 from CFA via concentrated sulfuric acid sintering. The influence of ultrasonic power and processing time were tested under the conditions as the same as those without ultrasound. It is found that the alumina extraction rate can reach 90.5 % with ultrasound assistance, while the ultrasonic treatment can reduce almost 15 ~ 30 min in leaching time and 5 ~ 10 oC in leaching temperature than those without ultrasonic operation at the same Al2O3 extraction rate. In addition, the ultrasonic can reduce calcium content by 6 ~ 8 % dissolved into the leaching liquid. SEM analysis also shows that the residue particle size with ultrasound is smaller than that without ultrasonic treatment.

Jan 1, 2015

By Xianwen Dai

One of the biggest challenges for the gold industry in the 21st century is the presence of copper in gold containing ore bodies. This is because copper consumes large quantities of cyanide. In addition, copper cyanide species are more stable than free cyanide, and hence are problematic in events of tailings spillage. The present paper compares cyanide and thiosulfate leaching for the recovery of gold from a copper containing ore. For cyanide leaching, the extraction of gold using copper cyanide complexes instead of free cyanide was tested in the presence and absence of added ammonia. For the thiosulfate leaching, the effect of the minerals present in the ore on the solution potential and thiosulfate consumption are illustrated.

Jan 1, 2003

By Jörg Buchmayer, Menno Eisenga, Erik Muijsenberg

"In the past decade, advanced multiple input/multiple output (MIMO) process control systems have found their way into high temperature melting processes. Today a growing number of high temperature melters have been equipped with a supervisory control system. Daily regulation of fossil fuel firing and electric energy supply to stabilize temperatures is no longer in the hands of the operator, but fully taken over automatically by the ES III™ MPC controller, which provides consistent process control, 24 hours per day, focused to operate the entire glass production process in the most efficient way. The presentation will show practical results and benefits achieved in the high temperature glass and cement industry.IntroductionThe Expert System, either version ESII™ or ESIII™, provides supervisory multi-variable model based predictive control in time and space This definition is not very understandable to people who are not familiar with advanced process control, thus let's try to explain it word by word.The word supervisory means that the Expert System implementation preserves the primary control level: all devices (PLCs, internal switches) as well as up to date control mechanisms (PID loops, availability to change inputs manually). ES III™ can even use primary control level elements as part of the advanced process control.The next word, multi-variable, means that multiple inputs can be handled at the same time to affect multiple outputs. This property is very important for supervisory control of the glass melting and conditioning processes. For example, in a float furnace the total amount of gas is only one of the inputs that affect the crown temperatures. The next one is batch feed rate. And batch composition (the next one) is maybe even more important. An ambient temperature also correlates with crown temperatures. So it can be concluded that crown temperatures are affected not only by one variable ""total gas"", but by many more. On the other hand, there are usually several crown temperatures with different importance for process control. And we have not discussed yet the effects of glass level, canal temperatures, oxy-boosting, etc. All of them affect (or are affected by) process control too. Overall, the process control is a complex problem where multiple inputs and outputs play strongly together at various levels of importance."

Jan 1, 2012

By Enrique Posada

"The Valle de Aburrá area, corresponds to the city of Medellín and neighboring municipalities, with more than 3 million people. The area generates a sizable amount of solid waste, which has been taken to landfills for the last 20 years. This paper proposes a model for public policy making which considers the cost and benefit of different alternatives to handle the wastes in the coming 20 years. Combinations of several alternatives: Recycling, waste reduction, waste separation, incineration, land filling with lixiviate treating and gas energy recovery, and organic waste composting are considered and modeled and the results presented as a contribution for a more rational approach to policy making than the one currently being employed.IntroductionThe author, working for INDISA S.A., acted as a consultant for the direction of planning of the Empresas Varias de Medellín in 2004. This entity has the responsibility for the handling of the solid wastes of the city of Medellín and some of the neighboring municipalities. At the present time more the 700.000 annual tons of waste are taken to the site of La Pradera, located in very rainy location (3.000 mm of precipitation per year), with complex in topography and very far away from the sources of the waste. During the work the author detected important problems that should be addressed, as follows:Lack of adequate technical administration and resources. The entity did not count with sufficient human resources to focus on the appropriate technical handling of the solid waste. The organization worked mostly with independent contractors, lacking enough coherence and integration. The internal workload was too large for the few people who had technical responsibility and this gave rise to attention problems. It is important to have clear technical procedures, technical know how and human resources, continuity in the activities. It is important to have a clear capacity to plan, to study, to make tests and monitoring, to pursuit and develop ideas, to optimize the processes and to introduce changes, to respond to environmental authorities, to the communities and to mass media and to handle the contractors. All this was basically lacking. In the case of the handling of the sanitary filling of La Pradera, for example, although the people in charge were very able and dedicated, the magnitude of the task was too large and the resources they had were insufficient. As a result, the site had at the time of the study, problems with thousands of vultures, lack of immediate cover up for the waste, uncontrolled leaching, the area being dirty and little attractive, despite being called a park."

Jan 1, 2008