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By Timothy W. Ellis, John A. Howes

The production of lead-acid batteries is defined by a closed-loop product life-cycle. Active material and grid alloys converge on an adaptable specification that improves both performance and recyclability. This mapping of product requirements for lead-acid batteries has taken over 80 years to develop. But, as the use of batteries made with other chemistries continues to grow, the need for a comparable life-cycle management process becomes increasingly apparent given societal needs to manage raw materials, e.g. the European Union Battery Directive recycling targets. What has taken more than 80 years for lead-acid to evolve in a closed-loop paradigm must now be accomplished in less time for batteries using other chemistries and technologies. End-of-life costs are embedded in the product cost of lead-acid batteries. However, end-of-life costs are not reflected in the product cost of batteries made with other chemistries. Those costs are borne by other constituencies with often inefficient and environmentally damaging results. Lead-acid is a materials technology management model for other products.

Mar 1, 2017

By Yuya Nakai, Kuniaki Murase, Kazuhiro Fukami, Atsushi Kitada, Ken Adachi

The resources of vanadium –titanium magnetite in China are very abundant, most of which are used to prepare titanium-rich materials. Titanium pigment, electric welding bar and titanium sponge are made from titanium-rich materials such as synthetic rutile and titanium slag etc. To fully utilize titanium resources, many production methods of titanium-rich materials were proposed. In this article, authors review on methods of preparing titanium-rich materials which are Electric Smelting Process, Reduction-rust Process, Selective Chlorination Process, Acid Leaching Process, and sum the advantages and disadvantages of them. Existing problems and possible tendency of production methods of titanium-rich materials are also discussed.

Mar 1, 2018

By V. Reiter, K. Reinharter, C. Wenzl, D. Gregurek, A. Spanring

The refractory linings in lead furnaces are exposed to several stresses rather complex in their interaction. In the present study the magnesia-chromite brick out of a lead recycling furnace suffered from a high chemical attack by the process slag. The high CaO, BaO and sulfur bearing silicate slag, as well as a high NaO2 supply from soda resulted both in a deep-reaching infiltration of the brick microstructure and a severe corrosion of the brick components. Both the sintered magnesia and chromite were attacked chemically. The FactSage calculations showed the formation of high amounts of liquid phase in the infiltrated microstructure. Further phenomena affecting the refractory performance such as iron oxide attack, redox effects, and boron attack are also discussed in the paper. The obtained information and insights serve as a basis for improving refractory materials (i.e., choice of refractories for individual process and new developments) and consequently furnace operations.

Mar 1, 2017

By Shijie Wang

Lifetime achievements of Professor Reddy ’s teaching, research and scholarship in the field of chemical and materials science and engineering are briefly described. He has devoted his entire career in the introduction and application of process engineering principles to the quantitative description of materials processing reactions, and industrial operations. He has formulated quantitative methodologies based on first principles of thermodynamics, phase equilibria and kinetics to: design of slags and fluxes for production and purification of metals and alloys; development of Reddy-Blander model for a priori prediction of impurities capacities of melts; development of novel ionic liquid electrolytes for materials processing; development of new theories for alloys and molten salts; design materials for fuel cells and capacitors; use of thermodynamic approaches to predict physical properties of materials; industrial energy waste separation and remediation; and thermal energy storage. He is a scholar and mentor, and has made numerous scientific and service contributions to the society and metallurgical and materials engineering education.

Mar 1, 2017

By Elizabeth Carvalho L. Cardoso, Ademar B. Lugão, Sandra R. Scagliusi

This research investigated how gamma-radiation affected PP/HMSPP structural foams filled with biodegradable synthetic polyester PLA in terms of thermal properties, biodegradability and infrared spectrum. Polymers are used in various applications providing enormous quantities of wastes in environment and contributing with 20–30% of total volume of solid residues. Besides, shortage of plastics resins obtained from fossil base is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction. PLA (poly(lactic) acid)) was chosen to be blended with PP/HMSPP. Blends thereof were subjected to gamma radiation at 50, 100, 150, 200 and 500 kGydoses.Soilburialtestpointedtowardapartialbiodegradationofirradiated PLA-PP/HMSPP foams; other characterizations involved TG/DTG technique and FTIR assessments.

Mar 1, 2017

By Haibin Wang, Kaile Tang, Chenn Q. Zhou, Guangwu Tang, Zhixiang Cui, Ping Zhou, Armin K. Silaen, Hongjie Yan, Zhi Wang

The submerged lance smelting furnace (SLS) for copper smelting has been developed and used by Dongying Fangyuan Nonferrous Metals Co., Ltd. The technology has shown advantages such as high oxygen enrichment, good feed adaptability, short processing time, high SO2 concentration for acid plant, and auto-thermal operation. In this study, computational fluid dynamics (CFD) was used to investigate the gas/matte two-phase flow characteristics and the chemical reactions in the SLS during typical operational conditions. The Eulerian-Eulerian approach was employed to model the phase interactions. The chemical reactions were modeled by calculating the mass transfer coef ficients and using the eddy-dissipation model. The simulation was conducted using the commercial software ANSYS Fluent®. The developed CFD model is able to predict the flow, temperature, and species distributions inside the SLS under various operating conditions.

Mar 1, 2018

By Christoph Czettl, Christian Storf, Gregor Kücher, Stefan Luidold

The purpose of this investigation is to provide a basis for the semidirect recycling of hard metals. The present investigation focuses on revealing the fundamental chemical kinetic aspects during cemented carbide leaching in hydrochloric acid media. The kinetic relations of cobalt binder leaching from WC-Co cemented carbide are studied using a central composite face-centered design of experiments with temperature, acid concentration, and hydrogen peroxide as variables.

Mar 1, 2017

By M. A. Usman, E. I. Akpan, S. O. Adeosun

Preliminary studies on the extraction and characterisation of biodegradable lignin from palm oil fruitbunch (POFB) for carbon fibre production has been conducted. Centra lComposite Design was used to determine the optimum operating conditions for maximum yield and properties of the extracted lignin. Soda concentration (1–3 wt/vol%), temperature (50–90 °C) and reaction time (20–30 min) were analysed using Rcore software. Experimental results show that using reaction temperature of 90 °C, time of 30 min and 3 wt/vol% soda concentration yields 3.3 g of lignin from 30 g of the POFB. The path of steepest ascent from ridge analysis shows that with temperature of 130 °C, time of 40 min. and soda concentration of 3. wt/vol%, 8.7 g of lignin can be extracted from 30 g of POFB. Analysis of FTIR and SEM show that the lignin has the same structure in all cases with minimal impurities.

Mar 1, 2017

By Qingyun Huang, Wei Lv, Junyi Xiang, Xuewei Lv, Chenguang Bai

The roasting is the key step for the extraction of vanadium from vanadium slag by calcification roasting–acid leaching process. In this study, thermogravimetric analysis and kinetic study of vanadium slag in the presence of calcium oxide was investigated. The maximum oxidation degree was slightly increased by increasing temperature from 700 to 900 °C then almost unchanged further increasing temperature to 1000 °C. The reaction mechanism was analyzed through both Sharp method and ln-ln method. Results showed that the mechanism the reaction in the a range of 0.1–0.8 corresponded to the random nucleation and subsequent growth, as represented as (G( a)=[ −ln(1−a)] 1/3 = kt. The apparent activation energy was calculated to be 3.5 kJ/mol according to Arrhenius equation.

Mar 1, 2018

By Jianhua Xin, Min Chen, Jin Xu, Hui Li, Nan Wang, Ming Chen

The kinetics study of blast furnace dust (BFD) recycling with flash reduction process at high temperature has been carried out using a high temperature drop tube furnace in laboratory scale. A combination characterization methods of chemical titration and SEM-EDS were used to track the reduction kinetics. The experiments using CO and CO2 mixtures with range of CO/CO2 (1:0, 1:1) at different temperature (1623–1723 K) and at different reduction time (1560– 2340 ms) were conducted. It was found that the reduction degree increases with the increase of temperature and reduction time as well as CO concentration. The carbon contained in the original BFD has weak in fluence on the reduction potential in the form of gasification. The unreacted core model was adopted based on the observation of the cross section and the measurement of iron element content, the effective diffusion coef ficient and reaction rate constant were determined and the rate controlling step was also analyzed.

Mar 1, 2018

By C. G. Bastos Andrade, F. R. Valenzuela Diaz, S. M. Toffoli

The climate change observed in the last decades, the increase of global warming, the melting of the polar ice caps, and the sea level rise have in common the non-sustainable development as causative agent. Different nations have mobilized joint efforts with the objectives of minimizing the impact of greenhouse gas (GHG) emissions, investing in the research and the development of new technologies in recycling, in biomaterials, environmentally friendly processes, and new fuel alternatives. This paper evaluates the efficiency of a Brazilian bentonite modified by acid attack, in the purification step of a waste oil to be used for biofuel production, that is, diesel from waste cooking oil (WCO). The following characterization test swere performed: XRD, CEC, XRF, SEM/EDS, specific surface area (BET), stereomicrography, kinematic viscosity, and spectrophotometry at 440 nm. The modified bentonite exhibited good purification capacity for WCO when compared to a commercial product.

Mar 1, 2018

By Muammer Kaya

This paper reviews the existing and state of art knowledge for electronic waste (e-waste) recycling. Electrical/electronic equipments (EEEs) which are unwanted, broken or discarded by their original users are known as e-waste. The main purpose of this study is to provide a review of e-waste problem, give e-waste management strategies and introduce various physical e-waste recycling processes with special attention towards extraction of both metallic values and nonmetallic substances. The hazards arise from the presence of heavy metals (e.g. Hg, Cd, Pb etc.), brominated flame retardants (BFRs) and other potentially harmful substances in e-waste. Due to the presence of these substances, e-waste is generally considered as hazardous waste and may pose significant human and environmental health risks if improperly managed. This review paper describes the potential hazards and economic opportunities of e-waste. First of all, an overview of e-waste/printed circuit board (PCB) components and substances are given. Current status and future perspectives of e-waste and waste PCB recycling techniques are described. E-waste characterization, dismantling, liberation, classification and separation processes, are also covered. Manual selective dismantling after desoldering and metal-nonmetal liberation at −150 μm with two step crushing are seen to be the best techniques. After size reduction, mainly physical separation processes employing gravity, electrostatic, magnetic separators etc., which are commonly used in mineral processing, have been critically reviewed here for separation of metals and nonmetals. The recovery of pure metals from e-waste after physical separation can be performed by pyrometallurgical, hydrometallurgical or biohydro metallurgical routes, which are not covered here. Suitable PCB recycling flowsheets for industrial applications are also given. E-waste recycling will be a very important sector in the near future from economic and environmental perspectives for both developing and developed countries. Recycling technology aims to take today’s waste and turn it into conflict-free, sustainable polymetallic secondary resources (i.e. Urban Mining) for tomorrow. Recycling technology must ensure that e-waste is processed in an environmentally friendly manner, with high metal/nonmetal recovery efficiency a lowered carbon footprint. Taking into consideration our depleting natural resources, this Urban Mining approach offers quite a few benefits; it provides a substantial secondary resource, while also ensuring that the environment is kept free from harmful toxins in e-waste. This results in increased energy efficiency and lowers demand for mining of new raw materials.

Mar 1, 2017

By Kai Hu, Xuewei Lv, Run Zhang

An oxygen sensor of zirconia-based solid electrolytes for in situ measurements of oxygen potential in high titanium slag was developed in the present study. With the facility, series of measurements of electromotive force were successfully conducted for different titanium slags at 1998 K under an argon atmosphere. Oxygen potential in the slag was calculated by the measured EMF and simultaneous readings of temperature using the modified Nernst equation. In addition, the relationship between slag compositions and the oxygen potential in the slag was explored in detail. It has been found that the oxygen potential increases with increasing FeO content in the slag and decreases with the increasing Ti2O3 content in the slag. The oxygen potential in the slag has been calculated thermodynamically and compared with the experimental measurements. The results showed that oxygen potential in the slag may be controlled by FeO/Fe equilibrium reaction.

Mar 1, 2018

By D. C. Austin, P. J. Hazell, A. A. H. Ameri, J. P. Escobedo-Diaz, D. East, M. A. Bevan, A. D. Brown

Additive Manufacturing (AM) has become increasingly popular due to the ability to produce components with complex geometries and properties. The efficiency of this manufacturing method is investigated in this paper by examining the mechanical performance of AM austenitic stainless steel 316L under different strain rates. Dynamic compression experiments were conducted by using a Split Hopkinson Pressure Bar (SHPB). Microstructural observations were performed by utilizing optical microscopy. The behavior of this material is compared against stainless steel 316L manufactured by conventional methods. The results show that theAM316L used in this study display a considerable difference in the mechanical properties compared with conventional stainless steel alloys.

Mar 1, 2017

By Sudha Goel, Manis Kumar Jha, Deblina Dutta, Rekha Panda

Based on the placement of lead and its consumption in industry bran- ches, the paper deals with the composition of lead in the massive of Kopaonik. Removal, tenuity and grinding of galenit. The paper in particular treats the flotation process, and also treats physico-chemical bases of reagents in the process, as well as decanting, drying, filtering and storage of concentrates. Veri fication of the chemical composition of Pb concentrates with Pb, Zn, Bi, As, Sb, In, Au, Ag, etc. It is special that in Kopaonik massive the ratio of Pb: Zn composition is 1.4:1.0 and during the flotation lead is inclined to go with pirotines concentrate more than is allowed. We are strongly focused to maximally decrease the Pb amount that goes with pirotine concentrates and wastes. The paper as such gave the first effects in optimizing of these parameters with positive effects in flotation process in Trepca.

Mar 1, 2018

By Zhiqiang Zhou, Shengnan Zhou, Zizong Zhu, Yuchuan Ding

The effect of silicon on removal of phosphorus from high phosphorus Si–Mn alloy was investigated at 1673 K by CaO-based slag. It was found that the dephosphorization efficiency increases significantly as increasing the silicon content, which is due to the reaction between silicon and CaO at slag/alloy interface. The relation between silicon content with oxygen activity and phosphorus activity coefficient of Si–Mn melt was determined respectively as follows: lg aO = -1:55xSi - 1:67; ln rP = 9:26e xSi 0:0433 + 11:0839 The carbon content in Si–Mn melt decreases continuously with the increasing silicon content, meanwhile, the decreasing rate of carbon content becomes rapid when the mole fraction of silicon is about 0.32. Si addition is beneficial for both dephosphorization process and low carbon Si–Mn alloy production.

Mar 1, 2017

By Ying Wang, Min Chen, Cuihuan Huang, Haohua Deng, Nan Wang, Ming Chen

Adding limestone directly into converter is considered to be favorable to energy conservation and emission reduction by transferring the decomposition reaction of limestone from the shaft or rotary kiln to the converter. In this paper, the kinetics of limestone decomposing in early converter slag was studied at 1300–1400 °C, and the effects of slag temperature and stirring speed introduced to the slag bath were examined. The kinetic results based on shrinking core model analysis showed that the limestone decomposition was a mixed rate control of chemical reaction and heat conduction through the lime layer, which could be promoted at higher slag temperature by supplying more heat to the converter bath. In addition, the chemical reaction rate constant and effective thermal conductivity were determined.

Mar 1, 2018

By Chonghe Li, Pengyue Gao, Xionggang Lu, Juyun Kang, Wajid Ali, Guangyao Chen, Ziwei Qin

A refractory U–Mo associated ore containing jordisite which enclose U, Mo component, and impede penetration, diffusion process of leaching, oxidation agent was investigated through three approaches of focusing on U, Mo extraction. The results indicate flotation beneficiation without followed metallurgical process is not appropriate because of high target metals loss rate via water leaching. H2SO4, H2O2 dosage recommended to oxidation leaching are 10 and 6–8% of ore mass, and U, Mo leaching rate are 92.71 and 52.16% respectively. For the acid pressure leaching, U, Mo leaching rate 93.75 and 76.07% are achieved under optimal temperature 130–140 °C and H2O2 dosage 8% combined with pressure air 0.6 MPa. Fluidized bed furnace roasting parameters include air flow rate 0.64 m/s, air ore ratio 0.3 m 3/kg at roasting temperature 550 °C with U, Mo leaching rate 93.2 and 89.5%, so enhanced metallurgical process effectively destroy wrapper and increase metal recovery rate.

Mar 1, 2018

By Fábio O. Braga, Sergio Monteiro, Artur C. Pereira, Foluke S. de Assis

The jute fiber is one of the most investigated natural lignocellulosic fibers due to its easy processing and extensive occurrence. However, the studies with some varieties of jute fiber such as the Corchorus capsularis are rare, so this wor kinvestigated the toughness behavior of polyester matrix composites reinforced with up to 30% in volume of a fabric made of jute fiber by means of Charpy impact tests. It was found that the addition of jute fabric results in a marked increase in the absorbed energy by the composites. Macroscopic observation of the post-impact specimens and SEM fracture analysis showed that transversal rupture through the jute fabric interface with the polyester matrix is the main mechanism for the remarkable toughness of these composites.

Mar 1, 2017

By Brajendra Mishra, Mark L. Strauss, Gerard P. Martins

Europium is a critical material required for LED, florescent lamp, cell phone screen, and flat panel display production. This process recycling europium from waste lamp phosphors is an innovative method to supply europium. The selective reduction and precipitation method using sulfate precipitation is investigated to recover high-purity europium from yttrium-europium mixed solutions.

Mar 1, 2017