冰醋酸-过氧化氢氧化法脱除煤中有机硫的研究

在用多种氧化剂对煤炭脱硫效果进行比较研究的基础上，筛选出脱硫效果最好的冰醋酸与过氧化氢混合物氧化剂，采用单因子法考察了氧化剂种类，煤与氧化剂的配比，氧化反应温度，反应时间，煤的粒度，冰醋酸与过氧化氢的配比对脱硫率的影响。优选出了冰醋酸与过氧化氢氧化法脱除原煤中有机硫的最佳工艺条件为；冰醋酸与过氧化氢的体积比为1：1，反应温度为104℃，反应时间为1h，煤与氧化剂的配比为3g:50mL，煤的粒度为粒径小等于0.23mm，在最佳条件下，原煤脱硫率可达到60.8%。     

不同煤矸配比脱硫试验分析

以一台130t／h循环流化床锅炉为研究对象，采用不同煤矸配比，以当地工业废渣为固硫剂，在不增加任何试验设备的情况下，进行炉内脱硫试验。结果表明，锅炉脱硫效果明显，试验取得了一定的成功。     

煤矸石烧结砖脱硫研究

在保证质量的前提下,以碳酸钙、生石灰、电石渣作为脱硫添加剂,通过各种调整配比,研究脱硫效果,结果表明:随着脱硫添加剂剂量的增加,效果都有增加,其中电石渣对煤矸石烧结砖的效果最佳,在950~1000℃烧成范围内,脱硫率能达到89%。     

固硫剂制备工艺探讨

探讨了循环流化床锅炉脱硫方法中固硫剂的制备工艺，对几种石灰石破碎设备及工艺进行了分析比较，通过柱磨机粉磨石灰石的工业试验，了解其产品粒度分布，从而择优确定固硫剂制备工艺流程。     

湿法烟气脱硫喷嘴雾化特性研究

通过大量系统的试验,从喷嘴体积流量、雾化粒径、雾化角、雾化粒度分布等方面对空心锥旋流喷嘴、螺旋喷嘴和实心锥喷嘴的雾化性能进行了详细的比较和分析，为湿法烟气脱硫工作中喷嘴的选型提供了依据。     

环保文摘

新的消石灰工艺应用石灰作吸收剂的烟气脱硫(FGD)系统,需将石灰消化为氢氧化钙(镁)细粒。粒度愈细,脱硫效果愈好。目前应用最广的消石灰装置是球磨机,存在负荷调节性能问题,并且不宜间歇运行。近年出现了二种新的工艺:一、立式搅拌磨搅拌磨(见示意图)的立式     

油页岩在流化床燃烧过程中放硫与固硫的数学模拟研究

为预测油页岩粒度、床温、钙硫比、床中灰分含量等参数对流化床二氧化硫排放量的影响，本文开发了耦合油页岩燃烧放硫、石灰石固硫和灰粒固硫的综合模型，并将该模型的预测值与实验结果进行了比较，发现两者吻合良好。本文的工作是研究工业化连续式油页岩流化床燃烧脱硫的基础，对茂名建设５万千瓦油页岩流化床燃烧热电站有重要的参考价值，并对于研究煤的燃烧利用有借鉴意义。     

简易湿式脱硫技术的试验研究

试验研究简易湿式脱硫技术中各种参数对脱硫塔阻力和脱硫效率的影响规律，并分析了脱硫塔内的气体速度分布状况。结果表明脱硫塔阻力小于３００Ｐａ，脱硫效率大于５０％，是一种投资省，阻力低，占地少，适合我国国情扔脱硫技术，具有广阔的开发应用前景。     

用于烟气脱硫脱氮的活性焦的研制

介绍了制备活性焦的工艺条件及其对活性焦性能的影响。制备活性焦的最佳工艺条件，原料配比为褐煤半焦；焦煤：煤焦油（质量比）为65：25：10；褐煤干馏温度为600℃，干馏气体介质为氮气；活性焦活化温度为850-950℃，活化时间为60-90min，活化气体介质为水蒸气/在最佳工艺条件下制备的活性焦，转鼓强度为96%-98%，碘吸附率为49%以上，经改性处理后的活性焦，脱硫率为90%以上，脱氮率为75%，试验结果表明，以沈阳地区的劣质褐煤为主原料制备的活性焦，不但对燃煤烟气具有良好的同时脱硫脱氮性能，而且具有价格低，催化活性高及机械强度高的特点。     

湿法脱硫废水处理技术

针对脱硫废水的特点，采用中和、絮凝、沉淀的原理，自主开发设计了一套脱硫废水处理装置，投资仅80万元，解决了脱硫废水二次污染问题，为湿法脱硫废水处理提供了一种有效的方法。     

Impact of different particle size distributions on anaerobic digestion of the organic fraction of municipal solid waste

Particle size may significantly affect the speed and stability of anaerobic digestion, and matching the choice of particle size reduction equipment to digester type can thus determine the success or failure of the process. In the current research the organic fraction of municipal solid waste was processed using a combination of a shear shredder, rotary cutter and wet macerator to produce streams with different particle size distributions. The pre-processed waste was used in trials in semi-continuous ‘wet’ and ‘dry’ digesters at organic loading rate (OLR) up to 6 kg volatile solids (VS) m^?3 day^?1. The results indicated that while difference in the particle size distribution did not change the specific biogas yield, the digester performance was affected. In the ‘dry’ digesters the finer particle size led to acidification and ultimately to process failure at the highest OLR. In ‘wet’ digestion a fine particle size led to severe foaming and the process could not be operated above 5 kg VS m^?3 day^?1. Although the trial was not designed as a direct comparison between ‘wet’ and ‘dry’ digestion, the specific biogas yield of the ‘dry’ digesters was 90% of that produced by ‘wet’ digesters fed on the same waste at the same OLR.     

The adsorption characteristics of heavy metals by various particle sizes of MSWI bottom ash

The incineration rate of municipal solid waste (MSW) has been increased because of difficulty in securing a proper disposal site for MSW in Korea. The advantage of incineration is reduction of the volume of waste; however, significant amounts of bottom ash and fly ash were generated in the incineration process. Their treatment has attracted growing interest because of the potential toxicity of hazardous heavy metals. Generally, heavy metals are less released from bottom ash than from fly ash. In this study the adsorption characteristics of heavy metals were investigated using various particle sizes of MSWI bottom ash. Since bottom ash has a broad particle size distribution, it was sieved to size classes of +20, -20, -48, -80, -100 mesh. Cation exchange capacity (CEC) was analyzed by the ammonium acetate method to evaluate the potential as an adsorbent. The CEC values and surface areas increase as the range of particle size becomes finer. The adsorption experiment was conducted using synthetic (Cu and Ni) and plating rinse water as a function of reaction time (10-180 min), liquid/solid ratio (2-100) and particle size (+20 to -100 mesh), respectively. The adsorption rate increased with decreasing particle size and with increasing liquid/solid ratio; however, the removal efficiency of Cu was higher than that of Ni. In the case of plating rinse water, the adsorption rate decreased sharply at high liquid/solid ratio, and it showed over 80% of adsorption rates for Cu and Ni at an initial pH of 3.     

Application of Dispersion Modelling for Analysis of Particle Pollution Sources in a Street Canyon

The dominating source of particles in urban air is road traffic. In terms of number concentration, its main contribution is within the range of ultrafine particles (Dp < 100 nm). The dispersion conditions, i.e. transport and dilution, of the submicrometer particles are expected to be like for gases and therefore the particle concentrations in a street canyon can be calculated using gaseous pollutants dispersion models. Such processes, like coagulation or condensation, are less important due to the short residence time within the street canyon environment.Two extensive measuring campaigns were conducted in the street Jagtvej in Copenhagen, Denmark. The particle size distributions were measured by a Differential Mobility Analyser (DMA) coupled to a particle counter, providing high time resolution data (1/2 hourly) on a continuous basis. Measurements of NO_x, CO and meteorological parameters were also available. The measured particle number concentrations, especially below 100 nm, reveal very similar dependence on the meteorological conditions as the NO_x concentrations. This underpins the conclusion that dilution properties are similar for particles and NO_x. For particle sizes over 100 nm, somewhat different behaviour is observed. This points toward existence of additional particle sources, not related to traffic emissions within the street canyon. A significant contribution is believed here to be attributed to long-range transport. The total particle emission from traffic, including daily variation and size distribution, has been calculated using the OSPM dispersion model. Results are in accordance with a previous analysis based on statistical modelling.     

Size distribution and metal composition of airborne particles in a waste management facility

Journal of Material Cycles and Waste Management - The objective of the current study was to measure the particle mass concentration, mass size distribution, and metal composition of airborne...     

Characterization and Leaching of Coal Fly Ash

Physical characteristics, chemical composition and leaching behaviour of a waste fly ash from a coal-fired power station are reported. Particle size distribution was studied by the following techniques: sedimentation in a liquid medium; sedimentation in an air flow; and Fraunhofer diffraction of a laser beam. Results obtained by the different methods are in good agreement. Mineralogical content and chemical composition were determined by X-ray diffraction, electronic microprobe and X-ray fluorescence. Acid leaching of the samples was investigated, using the following strong acids in sequence: HCl+ HNO₃, H₂F₂, HClO₄. Analysis of leachates by atomic absorption shows trace metals In, Tl, Ge, Cu, Ga, Pb, Ni, Co, Mn, Cd, Zn, Cr.In this work fly ashes from a Spanish power plant are characterized according to the type of particles, size distribution and chemical composition by means of physical methods. Three particle size fractions are leached by acids and analysis of trace elements in the leaching liquor is carried out. The concentration of trace metals is somewhat higher in the particles of smallest size.     

Novel fry-drying method for the treatment of sewage sludge

The purpose of this study is to introduce an efficient drying method named “fry-drying technology” for the treatment of sewage sludge. The basic principle of this method lies in the rapid escape of moisture from sludge material through its pores into the oil medium driven by the strong pressure gradient formed between sludge and oil media. This beneficial pressure distribution for moisture transfer can be established by the subtle combination of the difference of physical properties of specific heat and boiling temperature between water and oil. In order to determine the physical characteristics of this fry-drying technology, a series of experiments were performed in which important parameters, such as heating oil temperature, drying time, oil type, and sludge size, were varied. Numerical calculations using a single solid spherical particle model without any porosity were used to resolve the particle size effect associated with sludge drying.     

冷冻胶粉粒度对橡胶胶料力学性能的影响

研究了冷冻胶粉粒度对橡胶胶料力学性能的影响,发现添加冷冻胶粉会使胶料的力学性能下降,胶粉粒度越大,胶料性能下降的程度越严重。同时还发现,薄通处理可以改善胶粉的表面活性,减轻胶粉粒度对胶料性能的影响,改善胶料的力学性能。     

Characterization of metal concentration,heavy metal elution,and desalination behavior of municipal solid waste incineration bottom and grate sifting deposition ash based on particle size

Resource and environmental safety protocols of incineration residues were evaluated by analyzing the metal concentration, heavy metal elution, desalination behavior, and chlorine removal ratio owing to particle size differences between bottom ash (BA) and grate sifting deposition ash (GA). In the total content test, Cl, Zn, and Cr in the incinerator BA exceeded the cement acceptance standard (Cl: 1000 mg/kg; Zn: 1700 mg/kg, and Cr: 170 mg/kg) at almost all of the particle sizes, while Au, Ag, Pd, and Zn had high contents in the GA. When using BA as a construction material, heavy metal elution values and contents are restricted as per the product quality standards based on the Japanese soil pollution control law. Lead within the BA and GA exceeded the standard values for most particle sizes. We predicted that there would be a limit on the elution of K by only washing with water. The removal ratio of total chlorine by particle size was approximately 20–70%, where the effect of the particle size on the removal ratio was small, suggesting that the elution of chlorine was complete in approximately 6 hours. These results contribute to information on the recycling of BA and GA.

     

Nature of Atmospheric Aerosols over the Desert Areas in the Asian Continent: Chemical State and Number Concentration of Particles Measured at Dunhuang,China

Measurements of aerosol were made in August and October 2001, and January 2002, at Dunhuang, China (40°00N, 94°30E), to understand the nature of atmosphericparticles over the desert areas in the Asian continent. Balloon-borne measurements with an optical particle counter suggested that particle size and concentration had a noticeable peak in size range of super micron in not only the boundary mixing layer but also the free troposphere. Thickness of the boundary mixing layer, from distributions of particle concentration, was about 4 km in summer (17 August 2001), about2.5 km in fall (17 October 2001), and about 3 km in winter (11 January 2002), which suggest active mixing of particles near the boundary in summer. Number-size distribution of particleshowed a noticeable peak in the super micron particles size range inthe mixing boundary layer: 0.4–2 particles cm^-3 at diameter>1.2 m in summer, 0.05–4 particles cm^-3 at diameter >1.2 m in fall, and 0.1–5 particles cm^-3 at diameter>1.2 m in winter. In winter strong inversion of atmospherictemperature was found in the height range from the boundary to about 3 km and vertical distribution of particle concentration well corresponded with the temperature distribution. Chemical elements of individual aerosols, which were collectedin the boundary layer atmosphere at Dunhuang (18 October 2001) were analyzed with an electron microscope equipped with EDX. Thosesingle particle analysis suggested that most of the particles with supermicron size were soil particles, and those particles had littlesulfate on its surface. This is a very important different point,comparing with the chemical state of soil particles, which weretransported from the desert area of China to Japan, and showed frequentlythe existence of sulfate on the particle surface. Therefore, it isstrongly suggested that dust particles can be chemically modifiedduring their long-range transport from desert areas to Japan.     

Sinterability study of ceramic bodies made from a mixture of mineral coal bottom ash and soda-lime glass cullet.

The aim of this study was to investigate the sinterability to improve the technical properties of ceramic bodies made from coal bottom ash and soda-lime glass cullet. Different mixtures of bottom ash and glass cullet were formulated. The amount of bottom ash was 100, 70, 50 and 30 wt.%. The particle size distribution was the same for all formulations. The mixture containing 50 wt.% bottom ash also had its particle size distribution changed. Samples were formed by dry pressing and then fired at 950, 1050 and 1150 degrees C. Samples were evaluated for linear shrinkage, water absorption, flexural mechanical resistance, scanning electronic microscopy, pyroplastic deformation and thermodilatometric analysis. The higher firing temperature led to a decrease in water absorption and increased linear shrinkage, mechanical resistance and pyroplastic deformation. This effect was also observed for addition of glass up to 50 wt.%. The effect of smaller particles of bottom ash was more significant for linear shrinkage and mechanical resistance of ceramic bodies fired at 1150 degrees C. The use of a finer powder contributed to increase these properties. The influence of finer particles on water absorption and mechanical resistance of ceramic bodies fired at 950 and 1050 degrees C was not significant.