再生骨料透水混凝土体积法配比设计关键参数的优化选择

以再生骨料配制的透水生态混凝土为研究对象,用体积法进行配合比设计并调整不同的配比参数,研究保证再生骨料配制透水生态混凝土透水性和强度的最佳配比参数,并比较再生骨料与天然骨料配比设计中参数选择的异同。     

Possible use of waste serpentine from Abdasht chromite mines into the refractory and ceramic industries

There are approximately 20.5 million tons of waste rocks in Abdasht chromite mines which might cause considerable environmental problems in the near future. Serpentine is one of the most important rocks that can be abundantly found in this mine. In this work, the waste serpentine was processed by dry magnetic drum separator. Chemical analysis showed high content of MgO in the non-magnetic fraction (NMF) serpentine that reached to 47.85% after calcining at 1050 °C. The XRD result revealed that antigorite was the main phase of the NMF-serpentine while the major phase of the samples fired at 1050–1650 °C was forsterite. Considerable water absorption after 2 h dwell time at 1650 °C, indicated high refractoriness and high sintering temperature of the waste serpentine from Abdasht mines. These results proved the potential capability of waste serpentine from Abdasht mines as a raw material to be used in high temperature refractory and ceramic products.     

Performance of different process additives on the properties of mango powder obtained by drum drying

The use of process additives was evaluated in the drum drying of commercial mango pulp, using corn starch, maltodextrin 10/20 DE, and glyceryl monostearate (GMS). The mass flow rate (MFR) and some powder properties were analyzed: moisture content, vitamin C, total phenolic compounds, carotenoids, β-carotene, glass transition temperature (T_g), hygroscopicity, solubility, color, rheological behavior and color of reconstituted pulp. The pulps presented non-Newtonian and pseudoplastic fluid behavior, while T_g values ranged from 29°C to 38°C. The process performed with 3% corn starch and 0.5% GMS (dry basis) resulted in greater MFR (8.0?±?0.2?kg/h?m²) and vitamin C retention (61.0?±?0.7%).     

Improving the cold flow properties of biodiesel from waste cooking oil by surfactants and detergent fractionation

The use of surfactants and detergent fractionation to improve the cold flow properties of biodiesel from waste cooking oil (BWCO) was investigated. The effect of five types of surfactants, including sugar esters (S270 and S1570), silicone oil (TSA 750S), polyglycerol ester (LOP-120DP) and diesel conditioner (DDA) on the reduction of the cold filter plugging point (CFPP) of the BWCO, was evaluated, with the greatest reduction to the CFPP of the BWCO (from −10 °C to −16 °C) being was achieved by the addition of 0.02 wt% of polyglycerol ester (LOP-120P). Detergent fractionation of the BWCO was performed by first mixing partially crystallized biodiesel with a chilled detergent (sodium dodecylsulfate) solution accompanied by an electrolyte (magnesium sulfate), and then separating the mixture by centrifugation to obtain the BWCO liquid. An orthogonal experimental design was utilized to investigate the effects of the various parameters on detergent fractionation. The optimal parameters, as obtained by range analysis, were as follows: detergent loading 0.3 wt%, electrolyte loading 1.0 wt%, and water loading 150 wt%. The CFFP of the liquid biodiesel from waste cooking oil (LBWCO) was −17 °C with a yield of 73.1% when the detergent fractionation was performed under these conditions. A limited number of biodiesel physical and chemical properties were analyzed before and after the addition of surfactants and detergent fractionation.     

UASB-BIOFOR工艺处理柠檬酸废水

采用UASB-BIOFOR滤池组合工艺处理柠檬酸废水,对操作步骤及注意事项进行了详细介绍.实验结果表明,该组合工艺对柠檬酸废水处理效果良好,系统出水能够达到国家《污水综合排放标准》(GB 8978-1996)中的一级标准.     

硫酸法钛白粉生产废水治理的实验研究

硫酸法钛白粉废水含有大量的废酸,通常利用石灰制成的氢氧化钙乳浊液进行中和处理.电石渣是氯碱行业产生的废渣,主要成分为氢氧化钙,理论上可以替代石灰作为硫酸法钛白粉废水治理的药剂使用.实验通过对比石灰和电渣处理硫酸法废水的效果,分析电石渣替代石灰的技术可行性,为废物的利用寻求一个合理的途径.     

多晶硅金刚线切割废料制备Al-Si合金过程中的热力学和动力学分析

通过X射线衍射仪、X射线荧光光谱分析仪、傅里叶变换红外光谱仪分析了金刚线切割多晶硅废料的组分及其体系中存在的硅氧化物，研究了铝与切割废料合金化过程中可能存在的化学反应过程，采用HSC Chemistry 6.0软件对其反应体系进行了热力学分析，利用差热分析法研究了铝热还原切割废料中SiO2的动力学过程，对金刚线切割多晶硅废料进行了掺铝制备铝硅合金的实验研究。结果表明，金刚线切割多晶硅废料和铝粒按不同铝硅摩尔比兑掺后，在电磁搅拌的作用下，合金化的温度范围为800~1600℃，铝热反应可将废料中少量的SiO2杂质还原成单质Si，铝热还原二氧化硅的活化能为364.1 kJ/mol，反应级数为0.91，实验样品的EPMA和XRD等表征结果表明合金成分和渣相与热力学分析完全吻合，合金化效果明显。     

Improving the cold flow properties of biodiesel from waste cooking oil by ternary blending with bio-based alcohols and diesel from direct coal liquefaction

The utilization and popularization of biodiesel are always limited by its poor cold flow properties. Both bio-based alcohol and diesel from direct coal liquefaction (DDCL) has potential to enhance the cold flow properties of biodiesel. In this study, ternary blends of waste cooking oil biodiesel (BWCO) with DDCL and bio-based ethanol (ET) or 1-butanol (BT) were conducted to improve the cold flow properties of biodiesel. The pour point (PP), cold filter plugging point (CFPP), and cloud point (CP) of BWCO-ET, BWCO-BT, and BWCO-DDCL binary blends, and BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends were comparatively assessed. Ternary phase diagrams were also applied to analyze the blending effect of the three components on the cold flow properties of biodiesel. Results showed that both DDCL, ET, and BT can remarkably enhance the cold flow properties of BWCO. When the ternary blends contain 20 vol.% BWCO and less than 40 vol.% ET or BT, DDCL together with ET or BT exerted positive effects on enhancing the low-temperature flow properties of BWCO, especially on the CP and CFPP. For ternary blends in 20:10:70 blending ratio, BWCO-BT-DDCL exhibited the lowest PP, CFPP, and CP of −23, −19, and −17°C, respectively. The crystallization behavior and crystal morphology of blended fuels are also observed via a polarizing optical microscope, and find that DDCL together with BT in biodiesel can effectively retard the aggregation of large crystals and inhibit crystals growth.     

Preparation of silica/poloxamer composite by sol-gel process and pore control of silica gel obtained from the composite

Silica gels that controlled the pore size were prepared by calcination of silica/organic polymer (50/50 wt %) composites prepared by the sol-gel process. Poly(ethylene oxide) (PEO)-poly(propyrene oxide) (PPO)-PEO triblock copolymers, which are called poloxamers, were used as an organic polymer. The pore control of the silica gels was carried out by changing the molecular weight of PEO or PPO in the poloxamers. The silica gels obtained by the above procedure had a dual pore size of around 4 nm and below 2 nm in diameter, and the specific surface area was 500–1000 m²/g. The poloxamer molecules were supposed to be dispersed monomolecularly in the composites. Therefore, the pore structure of the silica gels reflected the structure of the poloxamer and, particularly, the radius of gyration of PPO in the composites. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 763–768, 1997     

酸溶置换法回收废甲醇催化剂中铜锌的研究

研究了采用酸溶置换法回收废甲醇催化剂中铜和锌的工艺，并着重对酸溶、置换、沉锌等环节进行了改进。探讨了回收废催化剂中铜和锌的过程中，废催化剂粒度、煅烧温度、酸溶的硫酸用量及质量分数、酸溶时间、锌置换铜的用量及时间、焙烧铜粉温度及时间、氧化铜与硫酸反应的时间及温度、沉锌时pH对锌回收率的影响，得出了适宜的工艺条件。在适宜工艺条件下，可以制备出产品纯度与附加值高的活性氧化锌和五水硫酸铜，回收率分别达94．3％与93．7％，产品质量分别达到GB／T3185-1992和GB437-1980标准，具有较好的经济效益和社会效益，市场前景广阔。     

Accelerated aging and contact with food simulants in adhesion of amorphous hydrogenated carbon films obtained by the PECVD process from recycled PET from packaging

This work focuses principally on the influence of time, temperature, and contact with food simulants in adhesion of amorphous hydrogenated carbon (a‐C:H) films obtained by the plasma enhanced chemical vapor deposition process in recycled PET from packaging. Shelf life of packaging used in soft drinks, fruit juice, etc. is known to be ～ 6 months, with possible variations. The a‐C:H film, used in this study as a functional barrier against possible contaminants in recycled PET, was analyzed to determine possible alterations in its physical and chemical properties. The film underwent an accelerated aging test and was exposed to contact with food simulants listed by the FDA. In this case, adhesion is one of the properties most in need of conservation. This property was analyzed by means of the tape test and scanning electronic microscopy. Superficial chemical alterations resulting from both the accelerated aging test and contact with liquids were examined by the contact angle. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Modification of the properties of concrete by a new pozzolan—a waste catalyst from the catalytic process in a fluidized bed

The zeolitic waste material studied (fluidized bed cracking catalyst, FBCC) is characterised by a content of more than 90 wt.% of SiO₂ and Al₂O₃, a mean grain size within 20-80 μm, and a specific surface above 100 m²/g. Its chemical composition makes it similar to some fly ashes and metakaolin. The present work was devoted to the study of the mechanism of interaction of FBCC with Portland cement and of the pozzolanic activity. Concretes were made with FBCC additions of 10% and 20% (relative to the mass of cement) used as a substitute for the sand aggregate fraction, and the following properties of the concretes were determined under nonaggressive conditions: compressive strength, porosity, water absorption, frost resistance, and steel passivation ability. It has been found that FBCC has pozzolanic properties, and its pozzolanic activity depends on its grain size. FBCC favourably modifies the porous structure of the concretes, increases their compressive strength, density, and frost resistance, and reduces water absorption. The effectiveness of FBCC increases under conditions of strong dispersion. FBCC does not deteriorate the steel passivation ability of concrete when used as a 10% additive, but at a content of 20 wt.%, it can make difficult the formation of a passive layer that conforms to the Polish standards.     

酸法联二脲生产中的缩合反应废水在加气混凝土砌块生产中的利用

将酸法联二脲生产过程中产生的缩合反应废水经简单处理后,用于加气混凝土砌块生产中,既减少此废水的排放量,又有助于实现ADC发泡剂的清洁生产。介绍了其原理与工艺流程。     

Determination of paraffin and aromatic hydrocarbon type chemicals in liquid distillates produced from the pyrolysis process of waste plastics by isotope-dilution mass spectrometry

Isotope dilution mass spectrometry was developed for the determination of composition of paraffins, olefins, naphthenes and aromatics in distilled oil produced from the pyrolysis reaction of mixed waste plastics using labeled hydrocarbon internal standards including octane-d₁₈, dodecane-d₂₆, hexadecane-d₃₄, benzene-d₆, toluene-d₈, ethylbenzene-d₁₀, 1,3,5-trimethylbenzene-d₁₂ and naphthalene-d₈. This technique made it possible to thoroughly quantify more than three hundred peaks in plastic-derived pyrolysis oil, classify pyrolysis oil into four hydrocarbon groups of paraffin, olefin, naphthene and aromatic, and determine the weight percent of each hydrocarbon group simultaneously. Compared with commercially available petroleum oil, distilled plastic-derived pyrolysis oil contained much more aromatics amounting to 60-82 wt% of whole hydrocarbons. Toluene (C7-benzene) and trimethylbenzenes (C9-benzenes) were the predominant species amounting to 40-50% of whole hydrocarbons in pyrolysis oil with a gasoline range boiling point and 25-35% of whole hydrocarbons in pyrolysis oil with a diesel range boiling point, respectively.