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By Niander A. Cerqueira, Pâmela Berçot, Afonso G. Azevedo, Victor B. Souza, Victor T. Bartolazzi, Bruno Padilha

In recent years, concern about environmental issues has become a parameter to consider in the projects in engineering. In order to reduce the impact that the tire improper disposal may result for the environment, we sought a solution to this problem. This article proposes the use of rubber scrap tires as fine aggregate in concrete production. The material produced was analyzed by a bending test, resulting in product quality, in particular for application in situations requiring a more ductile material.

Mar 1, 2017

By Wankun Wang, Fuchun Wang

Based on the study of artificial neural network, the neural model was established for the prediction of germanium extraction from zinc oxide dust by microwave alkaline roasting-water leaching. Alkali-material mass ratio, microwave heating temperature, liquid-solid ratio, aging time, leaching time and leaching temperature were the significant factors for the process. The results indicated that the neural network prediction model was reliable, and the forecast values fitted well with the actual experimental values. The model could be used to predict the regeneration experiments with high credibility and practical significance. The accuracy of convergence of the model reached 10−5.

Mar 1, 2018

By Mingming Zhang, Udaya Bhaskar Kodukula, Marcelo Andrade

The physical and chemical properties of sinter feed are important factors that determine the productivity and quality of sinter product. In this study the feasibility of treating sinter feed by high pressure grinding rolls (HPGR) is investigated for selective cracks generation exploiting weak zones along grain boundaries of poor quality iron ores without generating much fines. The pre-treated sinter feed was characterized for size distribution, surface area, contact angle, and SEM analyses. The characterization results indicated that surface area of the pre-treated sinter feed sample increased about 20%. Pot-grate sintering tests results also indicated improvement on cold permeability, sintering yield and productivity, sinter Tumbler index, and low temperature degradation index (LTD) after HPGR pre-treatment.

Mar 1, 2018

By D. Tait, M. A. Halim, V. I. Lakshmanan, R. Sridhar

Rare earth elements (REEs), nickel and cobalt find their use in developing strategic materials and their demand is consistently increasing in the world while the extractable ores of these metals are gradually depleting. Process Research ORTECH Inc. (PRO) has developed innovative mixed chloride leaching processes for the recovery of REEs from alumino-silicate ores, and nickel and cobalt from laterite ores. The addition of magnesium chloride in hydrochloric acid enhances the activity of the hydrogen ion by orders of magnitude, which permit rapid leaching rates at moderate temperature and atmospheric pressure, along with high metal recovery. Innovative solvent extraction process steps are used for the separation of these metals from pregnant leach solutions. PRO’s processes also produce value added by-product of high purity iron oxide and recycle chloride lixiviant to the leaching stage. This paper describes the leaching and separation reaction mechanisms and potential process flowsheets.

Mar 1, 2017

By L. E. K. Holappa

Iron and steel making plays a significant role in global energy consumption and carbon dioxide emissions. The target of limiting the global warming by 2050 is extremely challenging for this energy-intensive branch of industry. In order to be responsible for its own share in cutting CO2 emissions, great advancements must be done. A brief history, present situation and different scenarios are discussed. Possibilities to decrease CO2 emissions in current processes via improved energy efficiency, alternative process routes, energy sources and recycling are examined. On-going and planned efforts and programs of steel producers and institutions, as well as trends of energy generation in the long run are reviewed and evaluated.

Mar 1, 2017

By G. E. S. Lima, J. V. B. Lemes, F. G. D. Machado, J. Alexandre, L. G. Pedroti, L. A. F. Fioresi, W. E. H. Fernandes, R. C. S. S. Alvarenga

Cellulose fibers are extracted from renewable sources and have potential to be used in various fields. In this study, a type of Reactive Powder Concrete (RPC) was produced with the addition of Cellulose Nanofibers (CNF), a biopolymer extracted from lignocellulosic materials. Three different concrete compositions were produced, each with addition of 0.10, 0.20 and 0.25% of CNF in mass, proportionally to the cement’s mass. During the analysis were performed Scanning Electron Microscopic (SEM) tests, compressive strength and Young’s modulus tests after 1, 3, 7 and 28 days of production and shear and flexural strength after 28 days of production. The results showed that the addition of CNF in aqueous solution reduces the concrete’s workability and negatively affects mechanical properties.

Mar 1, 2017

By Shadia Ikhmayies

In this work Thermo-Calc software was used to calculate the phase diagram of the Fe–Si system. The deduced phase diagram includes twenty fields, where three fields represent pure phases; two solid solutions and a liquid phase. There are several fields of two co-existing phases; mixed solid phases, and mixed solid with liquid phases. A set of eutectic and eutectoid points were found, where transformation reactions and temperatures were identified. The results were compared with results in the literature and good agreements with some differences were found. This study is a step to understand the phase diagram of Ca–Fe-Si system for refining metallugical grade silicon (MG-Si).

Mar 1, 2018

By Bin Xu, Qian Li, Xin Min, Xiaoliang Liu, Yongbin Yang, Tao Jiang, Yan Zhang

The ringing characteristics of acid and alkaline iron ore pellets powder in kiln were studied by the thermodynamic calculation using software FactSage7.0, roasting experiments using briquetting method and analysis of SEM-EDS. The thermodynamic calculation demonstrated that liquid phase could be generated from alkaline pellets powder at a lower temperature and the amount of formed liquid phase was much more than that from acid pellets powder at the same temperature. Roasting experiments indicated that the compression strength of alkaline pellets powder briquettes were also higher than that of acid pellets powder briquettes. Additionally, the analysis of SEM-EDS suggested that the alkaline pellets powder briquette presented more liquid phase and a more compact structure comparing with the acid pellets powder briquette, which was consistent with the results of thermodynamic calculation and roasting experiments. Hence, in comparison with acid pellets powder, alkaline pellets powder is much easier to ring in the kiln.

Mar 1, 2017

By Toshiyuki Nohira, Tetsuo Oishi, Hideki Ono, Hirokazu Konishi

The electrochemical formation of Tb-Ni alloys was investigated in a molten LiCl–KCl–TbCl3 (0.50 mol% added) at 723 K. Open-circuit potentiometry was conducted using a Ni electrode after electrodepositing Tb metal at 0.20 V (vs. Li+/Li) for 300 s. There were four potential plateaus at (a) 0.66 V, (b) 0.80 V, (c) 0.95 V and (d) 1.56 V, respectively. Alloy samples were prepared by potentiostatic electrolysis at 0.60 and 0.70 V at 723 K. The alloy phase was identified as only TbNi2. Anodic dissolution of Tb from the formed TbNi2 was conducted at 0.90, 1.20 and 1.60 V, respectively. In the sample obtained at 0.90 V for 3 h, the existence of TbNi3 was identified by the XRD. Phase of the sample obtained at 1.20 V for 3 h was TbNi5. The sample obtained at 1.60 V for 3 h was Ni. Alloy samples were prepared by potentiostatic electrolysis at 0.50–0.80 V for 1 h using Ni plate cathodes in a molten LiCl–KCl containing TbCl3 (0.50 mol%) and NdCl3 (0.50 mol%). The highest mass ratio of Tb/Nd in the alloy sample was 56 at 0.70 V.

Mar 1, 2018

By D. Holdridge, D. Liao, S. Waterfall, N. Strobl, S. Sun

High melting point inclusions, such as spinel, alumina and AlO rich calcium-aluminates, have a strong tendency to agglomerate on the tundish stopper rod and Submerged Entry Nozzle (SEN) during the steel casting process, and eventually to cause SEN clogging. Calcium treatmen by wire injection during steel refining during Ladle Metallurgy (LM) is commonly used to modify these troublesome inclusions to lower melting point inclusions. However, too much Ca injection (Ca over-treatment) can cause operational issue (e.g. slide gate plate erosion),as well as increase Ca cost. Therefore, it is desirable to add an appropriate amount of Ca to avoid either under-or over-treatment. Based on inclusion analysis with an ASPEX® computer controlled scanning electron microscope (ASPEX) instrument, AlO and AlO rich calcium-aluminates were identified as a major cause of SEN clogging at ArcelorMittal Dofasco Electric Arc Furnace (EAF) steelmaking stream. A Ca treatment index was developed to improve the inclusion modification. The improved inclusion control has reduced SEN clogging and enhanced steel quality.

Mar 1, 2017

By Zongliang Zuo, Mengqi Wei, Huaqing Xie, Qingbo Yu, Qin Qin

The resource utilization of copper slag is an attractive option of iron resource. Thermal energy recovery and direct reduction (TER-DR) system was proposed in this study. By theoretica lanalysis,the exergy efficiency of this system can reach to 57.3%. To investigate the feasibility of TER-DR system, copper slag composite pellets within lignite were prepared. As a new binder, pinesaw dust was added into the pellets. The diameter of pellets was 20 mm in experiments and the compressive strength of them was up to 831 N when the addition ratio of biomass was 29%. The results showed that the overall iron recovery reached to 90% and the separated iron concentrate was up to 93.5% when thetemperature is at 1423 K for 90 min with CaO addition ratio of 0.3. The process reduces the secondary environmental pollution of copper slag and will be applied well in the future.

Mar 1, 2018

By Bhavani Kedika, Venkatagiri Noole, Krishna Thotla, Krishna Reddy Chepyala

Cationic lipids are attractive candidates for transgene delivery and expression and are safer alternatives to viral delivery vehicles. Here, we report the design, synthesis, characterization and transgene expression efficacies of a series of chrysin derived cationic lipids. A series of ten lipids of chrysin was synthesized by treating the 7-hydroxy group with dibromoalkane and further substitution of the bromo derivative with alkyl amines. The synthesized lipids were characterized spectroscopically. Parallel screening of the synthesized lipids for in vitro plasmid delivery expressing luciferase led to identification of several leads that demonstrated higher transgene expression when compared to the standard. Transgene expression efficacy was dependent on the chain length of the lipid. The influence of the various physicochemical properties on transgene expression efficacies was investigated. This study indicates that lipids derived from chrysin results in high levels of transgene expression and may be attractive for gene therapy applications.

Mar 1, 2017

By Dong-sheng Li, Hong-ming Long, Tie-jun Chun, Chao Ning, Zhen Wang

Iron ore sintering is an essential process in modern iron and steel production. It has the largest emission of the PM (particulate matter) in the iron and steel industry, accounting for about 40% of the total emission. The physical and chemical properties of PM 10 and PM 2.5 in the iron ore sintering were introduced, and the research development of PM emission reduction was also summarized. The potential future development of PM emission reduction by chemical agglomeration and capture in the iron ore sintering process was also carried out. The interface chemistry relationships between PM and polymer, such as sodium carboxy methyl cellulose (CMC) and polyacrylamide (PAM), in agglomerates were also investi- gated in this paper. It is signi ficant to reveal the characteristics of PM and develop the emission reduction technology of PM for the cleaner production of iron ore sintering.

Mar 1, 2018

By James Bennett, Jinichiro Nakano, Anna Nakano

Previous empirical research demonstrated that by mixing gasification and metallurgical slags at a specific composition in a CO2 enriched environment, enough exothermic heat would be generated to transform CO2 to CO. The process capacity may be limited by the availability of the slags, however, it could be used to supplement existing energy or chemical production to reduce overall carbon emission. In this study, computational simulations were performed to explore optimal process conditions based on effects of individual slag constituents and thermal input for maximal gas conversion rate, heat production, and volume increase. In simulated conversions of CO2 to CO and H2O to H 2, comparisons were made by varying CaO, FeO, versus V2O3 slag constituents. The result indicated the optimal slag composition may be obtained by appropriate source selection and mixing of gasification and metallurgical slags in order to maximize carbon reduction and/or H2 production.

Mar 1, 2017

By Yunhua Gan, Xiaowen Chen, Meilong Hu, Haige Li, Yang Tong

Ethanol is a kind of renewable fuel, which can be produced from biomass and applied in many energy areas, such as motorcar. The combustion of ethanol in meso-scale is facing great challenges, such as great heat loss, poor stability, and low combustion efficiency. Electro-spraying technique is an effective method to atomize liquid ethanol due to its great advantage of monodisperse and uniform characteristics. In present study, electro-spraying was applied in liquid meso-scale combustor to produce very small droplet diameter and uniform droplet distribution. Experiments were carried out based on nozzle-ring-mesh electrode structure using pure liquid ethanol as fuel. Electro-spraying characteristics were measured by Phase Doppler Anemometer (PDA) under different nozzle voltages, ring electrode voltages, flow rates, and steel mesh positions. The results may be helpful to the design of new meso-scale electro-spraying combustor using renewable liquid fuel.

Mar 1, 2017

By Mingming Zhang, Ramana G. Reddy

A 3-D mathematical model was developed for the batch reactor of low temperature aluminum electrowinning using ionic liquid electrolytes. This model describes the deposition process by incorporating the mass transport of participating ionic species, homogeneous chemical reactions within the diffusion layer, and the associated electrochemical kinetics. Processing parameters, current and potential distribution, species concentration, fluid flow distribution, and electrode spacing were evaluated for the optimal reactor performance. The results indicated that the electrode spacing significantly affects the electrolyte fluid flow and current density distribution. The parallel electrode configuration (in line with electrolyte inlet) improved the convection and resulted in uniform current density distribution and electrolyte fluid flow. However, for this electrode configuration, electroactive species distribution was most favorable between the electrodes. Perpendicular configuration of electrodes resulted in a more non-uniform fluid flow within electrolyte domain, and it has a potential to cause non-uniform deposits. Aluminum electrowinning experiments were conducted using batch reactor at 80 °C, electrolyte flow rate of 5–20 ml/min, and applied cell voltage of 3–3.5 V. Good agreement was obtained between the model and the batch aluminum electrowinning experimental results.

Mar 1, 2017

By Beatryz C. Mendes, Henrique de Paula Santos, Kléos M. L. Cesar, Eduardo Antônio G. Marques, Maurício Paulo F. Fontes, Rita de Cássia S. S. Alvarenga

Inadequate discard of industrial solid waste is a risk to human health and to the environment. Aiming at softening environmental damage caused by deposition on soil of an ink residue, from washing of printers used in carton box packages, it is intended to incorporate this residue into soil-cement bricks. The residue has other use potentialities such as in screeds, pavement parts, fertilizer, paints, etc. However, to explore these potentialities it is fundamental to assess the risks that the several forms of use of this residue can cause. For such, in this work the chemical analysis of the residue was performed in order to know its main chemical compounds, in addition to its characteristics of leaching and solubilization. The chemical composition assay showed traces of some heavy metals such as Pb, Cd, Cr, Zn, Al and Cu, although the residue-generating company uses ink labeled as heavy metals free. Among the elements analyzed in leaching and solubilization, some had concentration above the limit allowed by The Brazilian Codes. This code is based on CFR—Title 40—Protection of Environment—Part 260–265—Harzardous waste management. Therefore, it is suggested that the residue has a limited use to avoid contamination of ground water.

Mar 1, 2017

By Beatryz C. Mendes, Igor K. R. Andrade, Roseli O. G. Martins, Gustavo H. Nalon, Rita de C. S. S. Alvarenga, Leonardo G. Pedroti, Carol F. R. Santos, Marcelo A. Alves

This work presents an experimental investigation of the influence of concrete blocks and mortar’s compressive strength on the flexural bond strength, normal to the bed joints, of concrete structural masonry. Third-point beam tests were performed on concrete prisms, considering two different kinds of concrete blocks (compressive strength of 5.9 and 8.2 MPa) and six different cement-lime mortar compositions (compressive strength around 30, 70, and 120% of the blocks’ net area compressive strength). Units’ absorption and mortar’s initial flow and water retentivity were not varied, but remained within the suitable range for use in structural masonry. For both types of concrete blocks, it was observed an increase on the prism’s flexural bond strength with the increase of the mortars’ compressive strength. A lower mortar’s water-cement ratio led to higher bond strength. When fixing the ratio between mortar’s and concrete block’s compressive strength, it was noticed that the increase on the blocks’ strength contributed to a slight increase on the masonry’s flexural bond strength, except when using high strength mortar, in which the increase was significantly greater.

Mar 1, 2018

By Ender Keskinkilic

Pyrometallurgical studies conducted for Mn extraction using Turkish Mn-ore reserves were reviewed. Turkish Mn-ores are low-grade ones having *30% Mn. The most important Mn ore reserves in Turkey are in the Denizli-Tavas region, where more than 2 million tons of proven reserves are reported. Mining rights to the Denizli-Tavas manganese belongs to EregliIron and Steel Works Co. (ERDEMIR). The ore is usually charged to the blast furnaces of ERDEMIR during hot metal production. So far, nearly 20 Master’s thesis studies have been conducted for the analysis of manganese extraction in Turkey. In the scope of the present work, only pyrometallurgical and related activities (i.e. ore beneficiation, calcination, etc.) relevent to the treatment of a specific ore were examined.

Mar 1, 2017

By W. D. Judge, Z. W. Xiao, G. J. Kipouros

Rare earths have taken a prominent position in the Hi-Tech field after the discovery of the NdFeB permanent magnets. Their use in the magnets sparked miniaturization of the communication devices such as computers and mobile phones and are being considered in many more applications. Potential applications of rare earth elements in energy conversion technologies including wind turbines, photovoltaics, and other renewable energy systems are reviewed, along with sustainability considerations and production processes.

Mar 1, 2017