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By Run Huang, Xuewei Lv, Songli Liu, Chenguang Bai

"Titanium alloy was prepared from titania-bearing blast furnace slag (Ti-BF slag) by aluminothermic process in an induction furnace. The effects of aluminum amount on the titanium silicon yield and titanium recovery ratio were studied. The phase transformation and chemical composition of the prepared alloy were investigated by X-ray diffractometry (XRD) and X-ray fluorescence (XRF) respectively. It was found that the mass fraction of silicon and aluminum increased with increasing the aluminum amount, however, the mass fraction of titanium increased first and then decreased with increasing the aluminum amount. Furthermore, both the titanium alloy yield and titanium recovery ratio increased with the increase of aluminum amount. The main phases of the alloy were TixSiy and AlTi3. The titanium alloy samples prepared in various conditions had a composition (wt.%): 38–50% Ti, 29-34% Si, 4-11 Al%, 1.6-2.2 Mn%.IntroductionPanzhihua and Xichang regions in the southwest of China are rich in vanadium-titanium magnetite containing iron, vanadium, titanium and gangue. According to the characteristics of the resource, iron and vanadium are successfully recovered with a blast furnace process and a converter process. However, most content of titanium are entered in the blast furnace slag with TiO2 22% -26% and metallic Fe 2%–6% called Ti-BF slag. Due to the dispersed distribution of Ti in various fine grained mineral phases with a complex combination between Ca, Al and Si, it is difficult to recover the Ti components[1]. This slag is generated at a current rate of 3.6 million tons per year, which adds to the existing 70 million tons of slag produced so far[2]. The slag has had to be piled as large as the mountains, which not only waste of resources but also cause a pollution of the environment. Therefore, the study of integrated utilizing Ti-BF slag has become very significant."

Jan 1, 2012

By Licheng Zhou

The use of aquatic plants for the removal of heavy metals from wastewater has gained high interest. In this study, batch experiments were conducted to evaluate the adsorption of copper ions in aqueous solution by P. pectinatus L. under various conditions of contact time, initial pH of the solution, metal concentration and adsorbent dosage. The results showed that the maximum adsorption amount of copper ions by P. pectinatus L. was 22.60 mg/g when the initial copper ions concentration was 98.41 mg/L at pH 4.5. The Langmuir and Freundlich models were used to describe the adsorption equilibrium of copper ions on P. pectinatus L. and the adsorption followed the Langmuir isotherm. The adsorption kinetic was well-fitted with pseudo-second-order sorption equations.

Jan 1, 2009

By Rameshwar Sreenivasan

This paper presents a sustainability analysis of Selective Laser Sintering (SLS) from an energy standpoint. Data of electrical power consumed by the system over an entire build were acquired using a LabVIEW 8.6 circuit. The power drawn by individual subsystems was also measured, and an energy balance was performed. These data were then used to arrive at a Total Energy Indicator of the process with the help of a specific type of Environmental and Resource Management Data (ERMD) known as Eco- Indicators, which indicates the level of sustainability of the process.

Jan 1, 2010

By Jewel A. G. Gomes

Electrocoagulation (EC) has been performed with Al-Fe electrode system with changing polarity for the removal of arsenic from water. The removal process has been studied using ICP-AES and Anodic Stripping Voltammetry with a wide range of arsenic concentration (1-1000 ppm) at various pH (4-10) and residence times (1-60 min). Electrochemically generated by-products have been analyzed using XRD, FTIR, XPS, SEM/EDS and Mössbauer Spectroscopy. Results revealed expected crystalline iron oxides (magnetite (Fe3O4), lepidocrocite (FeO(OH)), iron oxide (FeO)) and aluminum oxides (bayerite (Al(OH)3), diaspore (AlO(OH)), mansfieldite (AlAsO4?2(H2O)), as well as some interaction between the phases. The amorphous or ultra-fine particular phase was also found in the floc. The substitution of Fe3+ ions by Al3+ ions in the solid surface has been observed, indicating an alternative removal mechanism of arsenic in these metal hydroxides and oxyhydroxides by providing larger surface area for arsenic adsorption via retarding the crystalline formation of iron oxides.

Jan 1, 2006

By A. E. M. Warner

At the Copper Cliff Smelter, Inco Limited has extensive experience in converting primary smelting mattes over a broad range of nickel/copper ratios and compositions. In the past 35 years, technology developments at Inco have reduced the number of Peirce-Smith converters in Nickel/ Bulk (nickel-copper matte) service from 13 to the current 5. This paper will discuss: ? The performance and life of ?stretch? 13.7m shells versus conventional 10.7m converters. ? Process control and information system development from the early 1980?s to view converter aisle status on a continuous basis to the recent central control of the stretch shells. ? Nitrogen cooling of finishing matte from plant testing to implementation in the early 1990?s to replace the dedicated cooling converters. ? The impact on converting of changing the smelter flowsheet in the early 1990?s. ? A current program to develop a converting strategy for the future to address environmental issues and profitability.

Jan 1, 2005

By Sergio Neves Monteiro

In the present work, a ceramic foam elaborated with illitic clays was characterized. Properties related to density and compression strength were determined in samples fired at 1300oC, a temperature that permits the clay structure to generate and retain gases that will produce the foamy structure. The microstructure of the ceramic foam was studied by X-ray diffraction, scanning electron microscopy and mercury porosimetry. The results showed that the ceramic foam presents a bulk density of 0.38 g/cm3. The microstructure is formed by large open pores, quartz particles and vitreous phase.

Jan 1, 2006

By José Carlos D?Abreu

The Tecnored process is a new ironmaking technology, developed on a unique approach that combined empirical and theoretical knowledge backed by extensive tests carried out in a dedicated pilot-plant and with close support of universities and research centers. Campaigns in the pilot-plant focused on operate different reactors of different sizes, including a full size slice of the industrial furnace. This approach provided actual conditions to develop the main features of the process such as the internal dimensions, raceway pattern, thermal and gaseous profiles, etc, besides provide reliable data to feed and calibrate a specific mathematical process modeling. This paper presents the first computer model used by the Tecnored technical staff, focusing the behavior of a self reducing agglomerate in the upper shaft of the furnace (zone of solid state reduction). Some results of this model are given and discussed.

Jan 1, 2006

By Vinay Kumar

The present investigation describes R & D studies carried out for recovery of copper from the sulfate solution expected from the leaching of e-wastes in presence of minor constituents such as cadmium, zinc and nickel using solvent extraction process. In order to extract copper in continuous mode in mixer settler unit (MSU), basic studies have been made to optimize the experimental condition using 5%LIX84 in kerosene. Subsequently, the solvent extraction of copper was made in MSU maintaining leach solution flow rate 4.0 L/h and A/O ratio 1. The results showed complete extraction (~97%) of copper in three stages at A/O ratio 1 from the aqueous solution containing 1.98g/L Cu at pH 1.91 in presence of impurities. Loaded metal was completely stripped after scrubbing with 10% sulfuric acid in two stages. The stripped solution could be used for metal/ salt recovery by electrolysis/ crystallization.

Jan 1, 2010

By Preston C. Holloway

Transformational roasting involves the heating of a material along with specific additives to induce mineralogical changes in the starting material. By controlling the chemical composition, roasting atmosphere, temperature and time of reaction, the mineral transformations induced during roasting can be engineered to control the distribution of valuable, or harmful, metals and to produce new mineral assemblages that are more amenable to conventional methods of metals recovery or to environmentally safe disposal. To date, this type of process has only been applied to the recovery of a limited number of metals, but current research is looking to expand the application of these techniques to the recovery of metals from a wider range of materials. An introduction to these techniques is presented along with preliminary results from their application to metals recovery from zinc bearing wastes, such as zinc ferrite leach residues and carbon steel electric arc furnace dust.

Jan 1, 2006

By Manis Kumar Jha

Leaching studies were carried out for the recovery/ recycling of metals from PCBs containing 17.05% Cu, 0.74% Ni, 1.74% Fe, 4.35% Pb and 8.32% Sn using various acids such as H2SO4, HCl and HNO3. While sulfuric acid was not a suitable leachant for the dissolution of metals from PCBs, hydrochloric acid selectively dissolved tin. The nitric acid was found to be effective lixiviant with the recovery of 99.99% Cu, Fe, Ni and 36.7% Pb in 6M HNO3 at S/L ratio of 100 g/L and 90oC. The kinetic studies carried out with 2M and 4M HNO3 at 90oC showed ?Ash diffusion control dense constant size-spherical particles? model.

Jan 1, 2010

By Keith S. McIntosh

The fire assay process for the quantitative recovery of platinum group elements (PGE?s) prior to subsequent analysis traditionally is a time-consuming process. Samples derive from various ore types and contain PGE?s at the ppm or ppb levels, making concentration of the elements mandatory before assaying. Traditionally sample turn-around times are of the order of 24 hours. The whole sequence of sample preparation, fire assay and subsequent analysis of PGE?s have been automated by Anglo Platinum. Some of the major challenges on the road to automation will be discussed and the novel solutions that were implemented. The engineered solution included robotic automation of the whole sequence, from sample preparation, up to the final element by element assay. The final system allowed for rapid (less than one hour) and accurate analysis of PGE?s even in streams containing very low levels, such as flotation tailing streams and drill core samples.

Jan 1, 2006

By Elisa Alonso

Manufacturing firms that rely on finite resources have a stake in ensuring sustainable materials use. Higher material prices and uncertain material supply, consequences associated with scarcity, can be damaging to firms. Firms have a number of options to improve material sustainability including dematerialization, material substitution and recycling. However, these options require technological capability, capital investments and supply-chain infrastructure; firms may decide to make such investments only if material prices increase. Once decisions are made, the barriers and delays to implementing changes may harm firms. The impact of not reacting to changes in material supply on firms was examined for the case of different platinum-using industries. It was found that taking action is particularly important for firms when limited material availability leads to volatile market conditions. Industries can benefit especially if they ensure process flexibility and have options for changing their material use patterns.

Jan 1, 2010

By M. S. Borges

The need for the waste management industry to reach environmental patterns, technological innovation, and a technological demand of the productive sector is covered by this study. The environmental care and responsibility in the industrial sector and the necessary cultural changes for companies and entities is also emphasized. A collaborative tool was developed to help all partners involved in the environmental administration. This tool focuses on the interaction among residue generators in the productive chain. It was developed for a vehicle assembler company supported by entities or institutions with emphasis in the research, development and innovation, with expertise and capacity for new products creation, as well as reuse, recycling and reduction of by-products generation. The work aims to establish a tool for socio-environmental management, focusing on promotion and interaction between industrial waste generators sectors.

Jan 1, 2010

By Shadia J. Ikhmayies

Nanocrystalline CdS:In thin films with particle size in the range (3-36 nm) were produced by the spray pyrolysis technique on glass substrates. The films were characterized by investigating their X-ray diffractograms (XRD), scanning electron microscope images (SEM), transmittance curves and photoluminescence (PL) spectra. The size of the nanocrystallites was estimated from XRD difractograms and then from the hyperbolic band model and the bandgap energies of the nano- particles, which were calculated from the positions of the minima in the first derivative curve of the absorbance. Fine-structured PL spectra confirmed the nanocrystalline nature of the films.

Jan 1, 2010

By Sergio N. Monteiro

Natural lignocellulosic fibers are successfully replacing synthetic fibers in many engineering applications. In addition to well-known conventional lignocellulosic fibers, others with promising properties are now being considered. The present work investigated the mechanical and structural characteristics of a relatively high strength fiber, curaua (Ananas erectifolius) from the Amazon region of Brazil. The results obtained from tensile tests confirmed the superior strength while scanning electron microscopy (SEM) analysis displayed features that justify the possibility of using the curaua fiber as an effective reinforcement for polymeric composites.

Jan 1, 2006

By Dirk van Zyl

As part of the North American regional activities during the Mining, Minerals and Sustainable Development Project (MMSD) one project focused on the development of sustainability evaluations at the operations level. Engagement was identified as one of the seven important questions to be addressed. Engineers and scientists employed in the mining, minerals and materials production arenas must understand the importance of stakeholder engagement, both within and outside the operations as it is essential in the ongoing activities required to contribute to sustainable development. After developing the awareness that a social license can only be contemplated if engagement is in place, they also have to develop skills in engagement processes. This presentation will present the business case for engagement as well as an approach to motivate undergraduate mining engineers to embrace it. The presentation will also review some recent and ongoing research to improve the engagement process.

Jan 1, 2010

By Zeljka Pokrajcic

Crushing and grinding, or comminution, circuits are the most energy intensive process of a mineral processing plant. Comminution involves the physical size reduction of an orebody to a particle size sufficient for recovery of the mineral values. However, the comminution process remains inherently inefficient. The inefficiency is a result of the operating nature of comminution devices such as grinding mills, where transfer of energy between grinding media and particles in unconstrained and completely random. New comminution circuit design strategies are presented in this paper. The aim of the new strategies is to improve the overall efficiency of the comminution process and reduce the total energy consumption of a comminution circuit. The energy efficient strategies include the: ? rejection of coarse size liberated gangue from the comminution circuit and further downstream size reduction ? use of more efficient grinding and crushing equipment ? the selection of coarser particle product sizes to alleviate the increased energy intensity required to achieve finer product sizes Singularly and when combined, these energy efficient strategies can significantly decrease the overall energy consumption of a comminution circuit. This paper also explores the financial impact of certain energy efficient strategies using an analysis tool called EcoNomics?. It shows that substantial financial gains can be made by including more efficient technologies and methods in comminution circuit design.

Jan 1, 2010

By Svetlana Nikitina

While many question "sustainability" as an intellectual field on the grounds that it is too broad and "undisciplined," we are able to achieve a good balance between breadth of coverage and depth of inquiry in our team-taught seminar "The Grand Challenges: Sustainable Development for the 21st Century" offered to first year students at Worcester Polytechnic Institute. We strike this balance between breadth and depth by a) problematizing key sustainability issues in class discussions; b) by explicitly exploring the lenses of different disciplines (the historical context, the scientific facts, the engineering interventions and the philosophical foundations of unsustainable behaviors); and c) by offering our students opportunities to pursue a targeted project on specific sustainability issues (vertical gardening, metals recycling on college campus) through which they gain depth of understanding as well as practical exposure to all components of the problem, which puts them on the path of seeking effective solutions.

Jan 1, 2010

By Hans Korfmacher

Product take-back regulations implemented in Europe have presented significant challenges to the consumer electronic product and battery industries. Initially companies established single compliance organizations within individual Member States. These programs met business needs but were inefficient and costly. They were protected from pressures of marketplace competition and could not leverage economies of scale. In order to address these problems P&G, Hewlett Packard, Sony and Electrolux conceived a pan-European compliance organization to collect waste electronic equipment Europe-wide. This organization, called the European Recycling Platform (ERP), operates in competition with existing national compliance systems. Since 2005 ERP has collected 800,000+ tons of waste electronic products and delivered millions of dollars in cost savings. This presentation reviews the steps needed to establish successful competitive collection organizations that provide sustainable recycling at the lowest cost.

Jan 1, 2010

By Jilai Xue

Experiments with various industrial cathodes ranging from 35 wt.% to 100 wt.% graphitic and fully graphitized carbons were carried out in a laboratory aluminum electrolysis cell. Sodium and cryolite bath penetration into the cathode samples was measured by XRD and SEM-EDS analysis. For a higher cryolite ratio in the bath, the cathodes with lower graphitic carbons exhibited more sodium penetration than the fully graphitized. The increased graphitization in the cathode materials can reduce Na, NaF and Na3AlF6 penetration. SEM-EDS inspection reveals that the sodium and fluorides penetration within the cathode samples has different patterns for varying graphitization of the carbon materials. XRD quantitative analysis indicates that there is a large percentage of Na3AlF6 in the penetrated bath. The results can provide useful information for quality evaluation of the industrial cathode products.

Jan 1, 2010