湿法石灰石/石膏烟气脱硫泵的选材及选型

简述了湿法烟气脱硫生产中浆液的性质，并根据浆液特点阐述了耐磨耐蚀泵的选材与选型．为湿法石灰石／石膏烟气脱硫浆液输送泵的研发提供参考。     

浅谈湿法脱硫增压风机的选型、安装、运行及维护

通过唐山热电厂2×300 MW湿法脱硫的工程实践,结合国内其他脱硫工程的选型及应用经验,对湿法脱硫工艺中的增压风机的选型、布置、安装、运行、维护进行了简单探讨.     

2×300 MW机组镁法脱硫吸收塔设计

氧化镁湿法烟气脱硫技术已在我国推广应用,在氧化镁湿法烟气脱硫工艺中,关健设备是吸收塔.以2×300 MW机组烟气脱硫工程为例,对吸收塔本体结构尺寸进行设计及选型,为镁法脱硫吸收塔设计提供参考.     

半干法脱硫技术在220MW机组脱硫改造中的应用

介绍了半干法脱硫技术在国电靖远电厂220MW机组脱硫升级改造项目中的应用,分析了脱硫改造选型的依据和过程,探讨了半干法脱硫设备的结构、特点及优势,为同类脱硫改造提供了参考。     

湿法脱硫技术关键问题研究

针对我国烟气脱硫存在的实际问题,研究了湿法脱硫关键技术,如多孔板环面积、层数、安装角度、孔径及开孔率,喷淋塔压力降特性等。解决了湿法烟气脱硫过程中关键问题,实现了除雾器的国产化,优化了物料分配技术,降低了脱硫石膏含水率,形成了一整套具有自主知识产权的湿式高性能脱硫技术,并成功应用于多个燃煤电厂商用脱硫工程,取得了显著的经济效益和社会效益。     

湿法烟气脱硫烟囱防腐技术探讨

介绍了湿法脱硫烟气的特点、腐蚀性；探讨了湿法脱硫火电厂烟囱的选型原则；重点讨论了钢烟囱的防腐设计，并对内衬的选型提出了建议。     

我国火电行业二氧化硫总量控制的研究

通过对我国火电行业二氧化硫总量控制的研究得出，要达到国务院批复的环保“十五”计划即二氧化硫总量降低10％，需要对老厂中燃煤硫分超过1％的35000MW机组采取安装脱硫效率90％的脱硫装置、2000年后投运的新厂均安装脱硫效率90％的脱硫装置等措施。     

挡板门在脱硫系统中的应用

脱硫系统中烟气挡板门是保证机组安全经济运行的重要设施.介绍了挡板门在脱硫系统中的实际应用、相关选型原则和控制逻辑等,并重点对旁路挡板门的控制方式进行了深入探讨,提出了多种保护措施,大大提高了机组运行的稳定性.     

湿法烟气脱硫工艺是否安装烟气换热器问题探讨

迄今为止,石灰石-石膏湿法烟气脱硫工艺已成为我国燃煤电厂烟气脱硫的首选工艺,而烟气脱硫湿法工艺是否需要进行烟气升温（即烟气脱硫是否需加装烟气换热器）的问题一直困惑着脱硫产业界.本文就安装烟气换热器（GGH）有关问题进行了阐述,提出石灰石-石膏湿法烟气脱硫工艺不宜安装烟气换热器的观点,供业内人士及有关决策部门参考.     

半干法脱硫配套电除尘器选型分析

某新建135MW机组锅炉为循环化床锅炉,其烟气处理系统采用半干法脱硫工艺加电除尘器。由于半干法脱硫后电除尘器入口的粉尘浓度非常高,且烟尘理化性质发生较大变化,除尘难度大,常规电除尘器的选型很难适应。分析了半干法脱硫后电除尘器选型的影响因素及各系数取值。     

Liberation characteristic and physical separation of printed circuit board (PCB)

Recycling of printed circuit board (PCB) is an important subject and to which increasing attention is paid, both in treatment of waste as well as recovery of valuable material terms. Precede physical and mechanical method, a good liberation is the premise to further separation. In this study, two-step crushing process is employed, and standard sieve is applied to screen crushed material to different size fractions, moreover, the liberation situation and particles shape in different size are observed. Then metal of the PCB is separated by physical methods, including pneumatic separation, electrostatic separation and magnetic separation, and major metal contents are characterized by inductively coupled plasma emission spectrometry (ICP-AES). Results show that the metal and nonmetal particles of PCB are dissociated completely under the crush size 0.6mm; metal is mainly enriched in the four size fractions between 0.15 and 1.25 mm; relatively, pneumatic separation is suitable for 0.6-0.9 mm size fraction, while the electrostatic separation is suitable for three size fractions that are 0.15-0.3mm, 0.3-0.6mm and 0.9-1.25 mm. The whole process that involves crushing, electrostatic and magnetic separation has formed a closed cycle that can return material and provide salable product.     

Aluminium flows in vehicles: enhancing the recovery at end-of-life

The transportation sector constitutes the major end-use market for aluminium-containing products and expectations for the future do indicate that aluminium will increase at 140 kg per vehicle. Moreover, up to 75 % aluminium recycled in Europe is used in transportation: thus, metal scrap recovered from ELVs is a key lever to act for closing material cycles. However, although the management chain of ELVs has an established procedure and aluminium scrap is usually recovered in shredding plants, a considerable fraction of the metal particles ends up in the light fraction called car fluff and is then landfilled. In this study we investigated potential of enhancing the recovery of aluminium scrap from the light fluff treatment. With this goal, the quantity of aluminium embedded in the Italian transport sector in the last 62 years was estimated, and a campaign of characterization in size and shape distribution of aluminium particles in the light fluff output has been carried out. The results estimated up to about 560,000 tons of metal are potentially recoverable from the treatment of light fluff at current operating conditions, but relevant improvements may be achieve when size and shape distribution criteria are adopt to implement eddy currents separation for a quantitative metal recovery.     

Electroactive Materials Composed of Starch

Extruded films of plasticized starch were doped with metal halides to produce solid ion-conducting materials. The electrical conductance of the material increased from 10^–11 to 10^–6 Siemens/cm. The type and amount of dopant affects the conductance of the material. Although the materials are moisture sensitive, water content does not have a significant effect on the conductance of doped films. Mechanical properties of doped films indicate that the starch is plasticized and that the ion-conducting material is strong and tractable. Unlike intrinsically conductive polymers, electroactive starch materials can be extruded in thin films or molded into any shape.     

Transmission electron microscopy (TEM) investigations of Mn-oxide rich cathodic material from spent disposable alkaline batteries

Transmission electron microscopy (TEM) techniques were used to investigate the spent cathodic material of a single common brand of disposable alkaline batteries. Mn-oxide particles are anhedral and irregular in shape and compose an estimated 99-95% of the <10mum size fraction of sample material. Diameters of particles vary widely and typically are between 50nm and 3mum; however, most particles are approximately 200-400nm in diameter. Chemical composition varies for Mn-oxide particles with concentrations being SiO(2) (0.00-1.52wt%), TiO(2) (0.49-4.58wt%), MnO (65.85-92.06wt%), ZnO (1.00-7.53wt%), K(2)O (4.97-20.48wt%) and SO(3) (0.43-2.21wt%). Discrete prismatic zinc crystals occur and vary from a maximum of approximately 0.8mum longx0.15mum wide, to 100nm longx20nm wide. Titanium metal was also observed in samples and composes approximately 0.25-1.0% of the <10mum size fraction of sample material. Results of this study suggest that battery components may be recycled in some special applications. Examples are low energy-low material requirement products such as paint pigments and Zn nanoparticles. This investigation provides detailed constraints on the nature of spent cathodic materials to improve existing recycling methods and develop new technologies.     

Material and heavy metal balance in a recycling facility for home electrical appliances

Collection and recycling of home electrical appliances was started in Japan in 2001 under a new recycling law. The law is aimed at promoting material recycling and at reducing the amount of waste to be landfilled. End of life products are processed by manual disassembly, shredding, and separation in 38 recycling facilities. The authors conducted a questionnaire survey and interviewed at some facilities to obtain information on process flow and material balance. By using the detailed records offered by one facility and by estimating the composition of recovered components, the material balance in the facilities was determined for four typical recycling processes. The heavy metal content of the recovered components was analyzed, then metal flow in the process was determined for each scenario. As a result, it was concluded that emissions to the environment of most heavy metals have been substantially reduced by the new recycling system, while a modest improvement in the rate of material recovery has been achieved.     

Comparison of different collection systems for sorted household waste in Sweden

Composition and quantity per person of municipal solid waste (MSW) have been analyzed in six municipalities in southern Sweden with similar socio-economic conditions but with different collection systems. Samples of residual waste have been sorted, classified and weighed in 21 categories during 26 analyses that took place from 1998-2004. Collection data of the total waste flow, including source sorted recycling materials, in the same area have been compiled and compared. Multivariate data analyses have been applied. Weight-based billing reduced delivered amounts of residual household waste by 50%, but it is unknown to what extent improper material paths had developed. With curbside collection more metal, plastic and paper packaging was separated and left to recycling. When separate collection of biodegradables was included in the curbside system, the overall sorting of dry recyclables increased. The large uncertainty associated with waste composition analyses makes it difficult to draw strong conclusions regarding the effects on specific recyclables or the changes in the composition of the residual waste.     

On-line detection of metal pollutant spikes in MSW incinerator flue gases prior to clean-up

SUWIC's unique mobile metals emissions monitoring laboratory has been used to measure metal pollutant spikes in the flue gas from a municipal solid waste incinerator, prior to gas clean-up. The laboratory has a heated sampling probe that extends into the plant, allowing the simultaneous on-line measurement of the concentrations of more than 30 metals by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). As little is known about temporal variation in metal concentrations, this capability is seen as a major advance. The graphs of continuous measurements show that the elemental loading is far from uniform, and that concentrations fluctuate far more than may have been conventionally expected. There are occasional significant spikes in the emission profiles for cadmium and mercury, which are believed to be due to specific items in the waste feed material. Continuous monitoring measurements are of significant value for those seeking to model metal behaviour in combustion and in pollution control devices.     

Formulation and Characterization of Biodegradable Packaging Film Derived from Potato Starch &; LDPE Grafted with Maleic Anhydride—LDPE Composition

There is a paradigm shift from non renewal resources to renewable resources in view of problems of disposal of plastic products after their life cycle. This paper deals with the approach, preparation and product properties of polymer prepared by using polysaccharide based biodegradable polymer. Basic material has been prepared by mixing LDPE, LDPE-g-mA (LDPE grafted with (0.5%) maleic anhydride (1:1)) containing a polar group in the LDPE backbone. Prepared basic material has been compounded in twin screw extruder with 0, 2.5, 5.0, 7.5, 10.0, 12.5 & 15% of Potato Starch. Thereafter, after conditioning blown film samples were prepared using extrusion film blowing technique, under temperature profile ranging from 120 to 160 °C. Packaging films have been prepared with maximum 15% potato starch contents and have been characterized by FTIR, DSC, TGA, and XRD techniques to ascertain its impact on some structural and thermal properties like thermal stability, flexibility, crystallinity, crystal size etc.     

Coal fly ash as raw material for the manufacture of geopolymer-based products

In this work coal fly ash has been employed for the synthesis of geopolymers. Two different systems with silica/alumina ratios stoichiometric for the formation of polysialatesiloxo (PSS, SiO2/Al2O3=4) and polysialatedisiloxo (PSDS, SiO2/Al2O3=6) have been prepared. The alkali metal hydroxide (NaOH or KOH) necessary to start polycondensation has been added in the right amount as concentrated aqueous solution to each of the two systems. The concentration of each alkali metal solution has been adjusted in order to have the right liquid volume to ensure constant workability. The systems have been cured at four different temperatures (25, 40, 60, and 85 degrees C) for several different times depending on the temperature (16-672 h at 25 degrees C; 72-336 h at 40 degrees C; 16-120 h at 60 degrees C and 1-6h at 85 degrees C). The products obtained in the different experimental conditions have been submitted to the quantitative determination of the extent of polycondensation through mass increase and loss on ignition, as well as to qualitative characterization by means of FT-IR spectroscopy. Furthermore, physico-structural and mechanical characterization has been carried out through microscopic observations and the determination of unconfined compressive strength, elasticity modulus, apparent density, porosity and specific surface area. The results have indicated that the systems under investigation are suited for the manufacture of pre-formed building blocks at room temperature.     

Olive mill solid residues as heavy metal sorbent material: a preliminary study

Biosorption of heavy metals is an innovative and alternative technology to remove these pollutants from aqueous solutions using inactive and dead biomasses such as agricultural and industrial wastes, algae and bacteria. In this study olive mill solid residue was used as heavy metal adsorbent material for its wide availability as agricultural waste and also for its cellulosic matrix, rich of potential metal binding active sites. Preliminary studies concerned with the removal of different heavy metals (Hg, Pb, Cu, Zn and Cd), the effect of pre-treatments by water and n-hexane and the regeneration possibility. Olive mill solid residue resulted able to remove heavy metals from aqueous solutions with an affinity series reflecting the hydrolytic properties of the metallic ions, but also a particular affinity for copper. It can be supposed that biosorption phenomenon occur by a general ion exchange mechanism combined with a specific complexation reaction for copper ions. Water pre-treatment is sufficient to reduce COD release in the effluent according to the law limit, while n-hexane pre-treatment strongly reduces also the adsorption properties of this material. Experimental isotherms obtained under different operating conditions were fitted using a non linear regression method for the estimation of the Langmuir parameters. Moreover a simple Scatchard plot analysis was performed for a preliminary investigation of the active sites, showing the presence of two different site affinities depending on the metal concentration, according to the previous hypothesis of two kinds of uptake mechanisms for copper biosorption. Regeneration tests gave good results in terms of yield of regeneration and also concentration ratios.