碘量法测定再生铜物料中铜的含量

采用硝酸、硫酸和尿素溶解样品,探讨了铅含量、氟化氢铵掩蔽剂的使用量和酸度对测定结果的影响,建立了再生铜物料中铜的碘量分析法。结果表明,铅含量为5%以下、pH=5~6时,测定结果稳定,碘量法加标回收率为98.6%~101.3%,相对标准偏差(RSD,n=12)为0.26%。与原子吸收分光光度法对比,测定结果吻合,表明碘量法测定再生铜物料铜含量准确、快速、稳定、可靠,适用再生铜的检测。

利用等离子技术治理再生纤维汽车内衬生产过程中的烟气

利用等离子技术,治理树脂聚合法生产再生纤维汽车内饰材料过程中产生的烟气,对等离子净化装置的结构参数、操作参数进行了优化,并对等离子体净化机理进行了分析。利用等离子技术,能够处理常规工艺设备无法治理的极微细可吸入颗粒物和气溶胶烟气;并可同时净化可吸入颗粒物和气态污染物。该设备结构简单、运行费用极低,可在产生烟气的很多行业和领域推广应用。

溶剂萃取法应用于混合铜锌原料的处理

溶剂萃取法(SX)精炼铜产品的产量已占全球产量的20%以上。近年来该技术已变得越来普及。作为处理铜矿石和铜精矿的新的湿法冶金设计方案,在智利、美国等国家,该方案正在被评估或已经在过去的几年中付诸实施。萃取工厂具有低投入、低运营成本和操作简单、可生产高品质电解金属产品的特点,该类工厂设置在矿场附近,使得溶剂萃取工艺在中小规模生产中具有经济性、适应性和可行性,而这种规模不适于采用传统熔炼工艺。在某些情况下,选择得到高度纯盐类化合物可能比生产金属产品成本更低。由于商业上的成功,2003年以来年产15万t锌、专门处理原生和再生物料的纳米比亚Skorpion锌联合冶炼厂,目前正利用ZINCEX^(TM)溶剂萃取技术建设一个新的锌扩产项目。铜萃取和锌萃取是成熟和完善的商业技术。对于处理混合或多金属铜锌矿石和再生物料的新的采矿和冶金工程,现在正是考虑应用该技术的好时机。本论文提供了溶剂萃取技术在以下两个工业生产应用中的设计特点和技术优势:(1)氧化铜/锌多金属矿堆浸以回收高纯度阴极铜锌;(2)处理烟尘和铜熔炼炉的电收尘固体颗粒以回收铜锌并除去某些杂质,例如砷。在这两个项目中,该技术评估结果都是积极的,显示出依靠溶剂萃取技术回收这些金属具有明显的技术优势和潜在的经济效益。

澳斯麦特工艺——21世纪的铜生产工艺

澳斯麦特顶吹浸没喷枪技术用于炼铜是一项低成本的处理原生和再生铜物料的成熟技术。无论是熔炼还是吹炼作业,在环境保护、提高生产效率和提高金属回收率方面均具有明显优势。本文回顾了澳斯麦特工艺在熔炼和吹炼原生和再生原料过程中的应用,探讨了澳斯麦特工艺的设计和使用原理,以及这些原理是怎样和终端用户的需求相结合的。

艾萨熔炼法——不只是昙花一现

艾萨炼铜法(CopperISASMELT)于20世纪90年代出现在世界金属产业中,现在,它每年要处理掉300万t精矿和再生铜物料。在澳大利亚、美国、比利时、印度、德国和中国的一些冶炼厂用浸没喷枪熔炼技术生产铜冰铜或金属铜。芒特·艾萨矿业公司的艾萨炼铜炉每年处理超过100万t的含铜物料。炉龄通常超过2年。本文介绍位于芒特·艾萨的艾萨炼铜炉的现状,并将它的性能与新近在中国和印度建造的2座炉子做一比较。文章还概括介绍了连续吹炼工艺的发展,该工艺将使用与艾萨熔炼法相似的工艺原理,它很可能会取代PS转炉。

Application of Biomaterials in Cardiac Repair and Regeneration

Cardiovascular disease is a leading cause of death throughout the world. The demand for new thera- peutic interventions is increasing. Although pharmacological and surgical interventions dramatically improve the quality of life of cardiovascular disease patients, cheaper and less invasive approaches are always preferable. Biomaterials, both natural and synthetic, exhibit great potential in cardiac repair and regeneration, either as a carrier for drug delivery or as an extracellular matrix substitute scaffold. In this review, we discuss the current treatment options for several cardiovascular diseases, as well as types of biomaterials that have been investigated as potential therapeutic interventions for said diseases. We especially highlight investigations into the possible use of conductive polymers for correcting ischemic heart disease-induced conduction abnormalities, and the generation of biological pacemakers to im- orove the conduction oathwav in heart block.

Regenerative Engineering for Knee Osteoarthritis Treatment： Biomaterials and Cell-Based Technologies

Knee osteoarthritis （OA） is the most common form of arthritis worldwide. The incidence of this disease is rising and its treatment poses an economic burden. Two early targets of knee OA treatment include the predominant symptom of pain, and cartilage damage in the knee joint. Current treatments have been beneficial in treating the disease but none is as effective as total knee arthroplasty （TKA）. However, while TKA is an end-stage solution of the disease, it is an invasive and expensive procedure, Therefore, innovative regenerative engineering strategies should be established as these could defer or annul the need for a TKA. Several biomaterial and cell-based therapies are currently in development and have shown early promise in both preclinical and clinical studies. The use of advanced biomaterials and stem cells independently or in conjunction to treat knee OA could potentially reduce pain and regenerate fo- cal articular cartilage damage. In this review, we discuss the pathogenesis of pain and cartilage damage in knee OA and explore novel treatment options currently being studied, along with some of their limitations.

Pyrolysis of Banana and Coffee Residues after Acid Hydrolysis

The use of the residues from renewable feedstock, besides the production of fuels, but also for the generation of other chemicals products, has become a priority. Superior plants have considerable potential as carbohydrate, aryl and fatty acids sources. However, the separation of the main constituents of the samples is necessary for several purposes in the biorefinery concept. The acid hydrolysis and pyrolysis processes are very promising technology, however, some adjustments in the conditions of pyrolysis are needed for different biomasses since carbohydrates were detected （14%-17%） in the residues after the conventional acid hydrolysis of these uncommon biomasses （coffee husk and banana stem and stalk）. On the other hand, it was showed that, by pyrolysis, it is possible to obtain from the solid residue after acid hydrolysis： pyrogenic carbon （charcoal with a yield of 48.5%-52.7%） for agriculture use （biochar） and valuable chemicals in the pyrolysis oil biooil fraction （that accounted by 26.4%-29.0%, free of water）, such as lignin monomers （32.6%-56.4% of the bio-oil） and fatty acids （30%-52.5%）.

Research Characterized the Physical Properties of Recycled Aggregate of Civil Construction Wastes

One of the big problems of the urban centres of the cities in Brazil is the growth of the generation of the Civil Construction Waste （CCW）. A disturbing concern for the public and private sectors is to find proper disposal of Urban Solid Waste （USW） in large cities, since suitable dumping sites for this waste are increasingly scarce due to the spread and development of large urban centres. In general, recycling is currently one of the procedures most studied by researchers for disposal of such waste. In this context and aiming a new application for recycled CCW aggregates, the research characterized the physical properties of the material to use in fill compaction piles in soil improvement. The analysis shows results from laboratorial tests executed in CCW recycled samples, which came from works in different construction stages from Recife-PE, and natural aggregate, adopted as a reference. Characterization tests were performed with samples CCW recycled CLue aggregates and samples of natural fine aggregate （stone powder）. The results of characterization tests showed similarities between the CCW samples tested and the reference samples, indicating that the civil construction wastes has potcntial use as material for consolidation piles in foundation works.

Introduction to a Fuel Continuous Mixer for Marine Diesel Engines＇ Application

To use the renewable fuels for marine field is still very limited due to the need of newly developed technology, highly requested safety （for gas fuel） and high price of biodiesel. Therefore, with some advantages, such as： simple producing process, reasonable price and simple modification technology needed, the blended SVO （straight vegetable oil） is recommended as suitable fuel for the marine application. Even though, there are some disadvantages of the blended SVO, such as a weak stability, layer separation in low temperature and some others. In order to apply the blended SVO as alternative fuel for marine diesel engines without the mentioned disadvantages, the paper will introduce a method to design and produce a fuel continuous mixer to make a blended SVO （palm oil）.

Influence of Recycled Construction Materials Aggregate on Mechanical and Physical Properties of Concrete

The main purpose of this research is to study the properties of re-use different types of construction materials such as PVC （polyvinylchloride） scraps, clay brick and recycled concrete as a partial replacement of coarse aggregate. Different proportions （1%, 3%, 5% and 7%） by weight were used for PVC. scrap, （10%, 20%, 30%, and 40%） by weight were used for recycled concrete and （5%, 10%, 15%, and 20%） by weight were used for clay brick. Mechanical tests such as compressive and tensile strength tests and physical tests such as ultrasonic pulse velocity, bulk density, porosity, specific gravity and water absorption tests were done to the samples after curing in normal water for 28 days. Test results showed slightly degradation in mechanical and physical engineering properties of concrete specimens that used partial replacement of recycled concrete coarse aggregate, degradation increased with increasing of replacement but test results still closely to reference samples. Use of polyvinyl chloride in proportions not more than 5% as a partial replacement of coarse aggregates given acceptable results in comparison with reference samples but all test results degraded at 7% replacements. Test results of partial replacement of crushed brick coarse aggregates unacceptable and the range of degradation are wide because of increased （water： cement） ratio to improve the concrete workability.

The Suitability of Maize as a Bio-ethanol Crop in South Africa

Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy sources; and by addressing environmental issues. It is an absolute necessity in South Africa to utilise sustainable and renewable energy sources, such as biofuels, but the production of bio-ethanol will ultimately place pressure on the limited and fragile agricultural resources of the country. Because of the proposed bio-ethanol plant at Bothaville this paper will firstly develop a methodology suitable for South African conditions in order to establish whether agricultural crops could be used for the production of biofuels. Secondly, it probes the suitability of maize as a biofuel crop in this country by investigating four possible bio-ethanol potential scenarios which are qualitatively formulated to provide a comprehensive overview of this study. Only in the best-case scenario could maize produce the required volumes as set out by the South African government for 2013.

Fundamental study on iron ore sintering new process of flue gas recirculation together with using biochar as fuel

It is of great significance for cleaner production to substitute bio-energy for fossil fuels in iron ore sintering. However, with the replacement ratio increasing, the consistency of heat front and flame front is broken, and the thermal utilizing efficiency of fuel is reduced, which results in the decrease of yield and tumble index of sinter. Circulating flue gas to sintering bed as biochar replacing 40% coke, CO in flue gas can be reused so as to increase the thermal utilizing efficiency of fuels, and the consistency of two fronts is recovered for the circulating flue gas containing certain CO2, H2 O and lower O2, which contributes to increasing the maximum temperature, extending the high temperature duration time of sintering bed, and results in improving the output and quality of sinter. In the condition of circulating 40% flue gas, the sintering with biomass fuels is strengthened, and the sintering indexes with biomass fuel replacing 40% coke breeze are comparative to those of using coke breeze completely.

Challenges on the Quality of Biomass Derived Products for Bringing Them into the Fuels Market

US EPA recently issued the final definition for a renewable fuel establishes rule for the revised Renewable Fuel Standard RFS the compliance for each part of its name： （i） to II （Renewable Fuel Standard）. The main be a fuel and （ii） to be produced from renewable biomass. This paper addresses the challenges faced by biomass derived fuels on meeting the specifications of those fuels （gasoline, diesel and heating oil）. Biomass-derived products contain oxygenates, some of which might enhance certain fuel specifications, but some others may have deteriorating effects. On directly derived from biomass pyrolysis have been demonstrated to the basis of available data published in the literature, the fuels be far from the concept of ＂substantially similar＂ transportation fuels. Upgrading is required to convert pyrolysis products into fuels that meet specifications. The economical viability of upgrading still faces confirmation, and imposes several technical challenges for truly attractive cost-effective approaches.

Biodiesel from Algae

Fossil fuels are non-renewable, and their quantities have been reducing because of pumping. On the other hand, the traffic is still developing and needs for fuels are growing. As a consequence people are forced to look for other sources of getting fuel. Additional reason for this has been steadily boosting the prices of crude oil and gas. Diesel, as fuel that is often used, is possible to produce from different feedstock （oil rape, soybean, sunflower, palm, waste animal fats, algae, etc）. In this paper, the author analyzes the possibility of obtaining biodiesel from algae and the feasibility of such a method of producing biodiesel. Algae for biodiesel production are analyzed and the systems in which they are growing are described. Experience in this area is described as well as opportunities for further development of technology for getting biodiesel from algae. Algae are very resistant and can grow virtually anywhere in the desert, in salt and fresh water and even in the waste water. Algae can reproduce quickly; they use C02 for photosynthesis and less water than other crops. Bio fuel from algae is biodegradable and contains no sulphur and it is not toxic.

New Renewable Source of Energy from Municipal Solid Waste Plastics

The use of renewable energy is not new. More than 150 years ago, wood, which is one form of biomass, supplied up to 90 percent of our energy needs. Today, we are looking again at renewable resources to find new ways to use them to help meet our energy needs. Overall consumption from renewable sources in the United States totaled 6.8 quads BTU （quadrillion Btu） in 2007 or about 7 percent of all energy used nationally. Consumption from renewable sources was at its highest point in 1997, at about 7.2 quads. Over half of renewable energy goes to producing electricity. Renewable energy plays an important role in the supply of energy. Even with the current fluctuating prices for fuel, U.S. residents and businesses pay a significant price for their utilities. Emissions from the evaporation and combustion of these traditional fossil fuels contributing to a range of environmental and health problems, causing poor air quality, and emitting greenhouse gases caused global warming. The method of producing alternative energy from municipal solid waste plastic is considered an effective way to meet the demand of energy need and save the environment at the same time.

Recycling of Crushed Demolished Concrete in Structures

Most important problems arising from industrial and technological developments are abundance and harmful effects of post-productive wastes. In most of the developed countries, these effects are avoided by orderly storing methods. Storing the wastes in random stacks in the site, and their effect on wide areas gives a rise to the risk of ground, air and under water pollution e.g., pollution of the surrounding environments. Therefore, in most engineering branches, effects and nature of harmful wastes are investigated and solution methods are developed. When structures made of concrete are to be demolished. Concrete recycling is an increasingly common method of disposing of the rubble. Concrete debris was once routinely shipped to landfills for disposal, but recycling has a number of benefits that have been made it a more attractive option in this age of greater environmental awareness, more environmental lows, and the desire to keep constant costs down. The purpose of this research is to study the effect of using demolished concrete as a reproducible coarse aggregate in fabricating normal and high strength concrete mixes. The effect of constituent materials in general and the recycled coarse aggregate in particular on the mechanical performance of the produced concrete mixes is investigated. The characteristics of using the by-pass product of cement industry as cementitious material in recycled concrete mixes with a percentage of 50% as a replacement of cement content is investigated too. Test results presented in this research leads to the promising use of crushed demolished concrete along with the by-pass product of cement as waste materials in producing concrete mixes as well as the optimistic results in enhancing the strength properties of plain concrete beside their benefits of the cost savings and reducing environmental impact.

Environmental analysis of innovative sustainable composites with potential use in aviation sector -A life cycle assessment review

The forecast of growing air transport in the upcoming decades faces the challenge of an increasing environmental impact.Aviation industry is working on promising technologies to mitigate this environmental impact.Lightweight design is a strong lever to lower the fuel consumption and,consequently,with it the emissions of aviation.High performance composites are a key technology to help achieve these aims thanks to their favourable combination of mechanical properties and low weight in primary structures.However,mainly synthetic materials such as petrol based carbon fibres and epoxy resins are used nowadays to produce composite in aviation.Renewable materials like bio-based fibres and resin systems offer potential environmental advantages.However,they have not found their way into aviation,yet.The reasons are reduced mechanical properties and,especially for the use of natural fibres,their flammability.Improvements of these shortcomings are under investigation.Therefore the application of bio-based and recycled materials in certain areas of the aircraft could be possible in the future.Good examples for applications are furnishings and secondary structures.The motivation for this paper is to give an overview of potential environmental properties by using such eco-materials in aviation.Life cycle assessment(LCA) is a tool to calculate environmental impacts during all life stages of a product.The main focus is laid on the bio-fibres flax and ramie,recycled carbon fibres and bio-based thermoset resin systems.Furthermore an overview of environmental aspects of existing composite materials used in aviation is given.Generally,a lack of LCA results for the substitution of synthetic materials by bio-based/recycled composite materials in aviation applications has been identified.Therefore,available information from other transport areas,such as automotive,has been summarized.More detailed LCA data for eco-composite materials and technologies to improve their properties is important to understand potential environmental effects in aviation.

Cytocompatibility of regenerated silk fibroin film:a medical biomaterial applicable to wound healing

Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.

Evaluation of solar aided biomass power generation systems with parabolic trough field

Solar and biomass are both renewable energy resources.Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources.However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource.The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency.In this paper,a concept of integrating solar into a biomass power generation system is put forward.In the system the oil heated by a parabolic trough solar field is used to replace the extraction steam to preheat the feed water(entering a biomass boiler) and the previous extraction steam thus saved can continue to do work in the lower stages of turbine.The performance of the hybrid system with different replacements is analyzed and compared through two typical solar aided biomass generating units.The results show that the integration not only reduces the consumption of biomass fuel(at the same generation capacity) but is also proved to be an efficient way to convert solar thermal energy into power.The results also show that with the same solar aperture area,the higher the grade of the replaced extraction steam,the better the thermal performance and economy.