Acid rain effects on the exterior durability of architectural coatings on wood

Acid rain is an important consequence of pollutants generated by modern industrial societies and is known to cause damage to ecological systems, construction materials and cultural artifacts. The assessment of the damage caused to paint films has included laboratory, exposure chamber, and exterior weathering experiments. This study uses visual assessment of paints applied directly to southern yellow pine and exposed at 30° south to either natural acid rain or deionized water spray sites in North Carolina and Ohio to determine damage by acid rain. An acrylic latex paint with a pigment volume concentration (PVC) of 52 and a volume solids (VS) of 35% was formulated with calcium carbonate or sodium potassium alumino-silicate extenders. This high PVC paint formulation is one known to stress the binding capacity of the latex and thus produce early grain cracking failures over bare wood. Major effects observed include severe yellowing and increased mildewing of the carbonate containing paints exposed to acid rain. While acid rain can damage exterior paints, much of the damage can be minimized by careful selection of the polymers and pigments used in the formulation.     

铝土矿的细菌浸出及微生物代谢产物试验研究

就细菌浸出方式、矿物品格结构、菌种的不同来源及其分解代谢物种类、数量、能力等四个方面对铝土矿的硅酸盐细菌浸硅效果的影响进行了试验研究和分析。结果表明,五种不同来源的硅酸盐细菌都能较好地从各种铝土矿中浸出硅,硅浸出率范围为35.3%-65.3%,其中JXF-1菌株浸出硅的效果最好;试验采用了四种不同的浸出方式,其中,利用预先在有被浸矿样且含蔗糖的培养基中培养的菌种,然后在有糖培养基质中对矿样进行浸出,硅的浸出率最好,从各种矿样中浸出硅的范围为25.7%-65.3%,比其它浸出方式高10%以上。在各种类型的被浸矿样中,细菌对层状结构的绿泥石浸出效果最好,可浸出其中65.3%的硅,而架状结构的正长石被细菌浸出的硅只有25.7%。硅酸盐细菌在不同的培养基中可以合成大部分的氨基酸、多糖和酒石酸、柠檬酸、苹果酸等四种主要的有机酸,各种代谢产物均对高岭石中的硅有一定的浸溶作用,试验表明,氨基酸、有机酸、多糖三者混合物溶解高岭石中硅的量比单独代谢产物的溶解硅的量分别高357.99%、291.89%、1186.1%。     

粉煤灰地聚合物溶出聚合机理及其性能研究

研究粉煤灰在碱性激发剂作用下硅、铝、钙的溶出聚合机理,并研究了生成的粉煤灰地聚合物的抗压强度、微观结构和形貌特征.研究表明:在地聚合反应中,粉煤灰玻璃质球体溶蚀,硅铝相不断溶出且逐渐增加,继而再聚合生成地聚合物凝胶,钙质成分部分键合在地聚合物中以平衡电价,部分参与水化反应生成相应的水化产物;粉煤灰地聚合物在75℃养护8...     

铝硅酸盐玻璃拉薄方法研究

对铝硅酸盐玻璃生产进行了科学计算,对超薄玻璃拉薄过程中存在的问题进行了原因分析,并结合实际情况开发了新的拉薄工艺,有效地实现了铝硅酸盐的拉薄生产。     

Novel inorganic ion exchange materials based on silicates; synthesis, structure and analytical applications of magneso-silicate and magnesium alumino-silicate sorbents

Two novel inorganic ion exchange materials magneso-silicate and magnesium alumino-silicate have been synthesized under identical conditions. The structure of these materials was established by chemical analysis, X-ray diffraction, thermogravemetric and differential thermal analyses, Fourier transform infrared spectroscopy and X-ray fluorescence analysis. Magneso-silicate and magnesium alumino-silicate were found to have the formulas MgSi(5.59)O(12.18).5.93H(2)O and MgAl(2.32)Si(5.2)O(14.88).18.23H(2)O, respectively. The structure of both sorbents was arranged and predict according to the ChemDraw Ultra program. The ion exchange capacities of these materials for some radionuclides and heavy metals Cs(+), Co(2+), Cd(2+), Zn(2+) and Cu(2+) were investigated and the data obtained showed that magnesium alumino-silicate has a higher capacity for these cations compared to magneso-silicate. Distribution coefficients in nitric acid medium have been evaluated to explore the separation potentiality of magneso-silicate and magnesium alumino-silicate for Cs(+), Co(2+), Cd(2+), Cu(2+), Zn(2+) and Fe(3+) ions. Sorption isotherms for all cations were investigated and the data showed the applicability of Freundlich isotherm for all cases.     

ASP驱油过程中蒙脱石的碱溶规律研究

研究了蒙脱石与碱剂（Na2CO3,NaOH)间的作用,考察了浓度,聚合物和NaCl对蒙脱石与碱剂相互作用的影响,蒙脱石在强碱和弱碱溶液中都发生了溶蚀作用,在氢氧化钠溶液中还生成了新硅铝酸盐沉淀,蒙脱石在强碱溶液中溶蚀更剧烈,并随强碱溶液浓度增大溶蚀加剧,聚合物加入到碱剂中对蒙脱石的溶蚀影响不大,加入NaCl于碱剂中蒙脱石的溶蚀略有增大,蒙脱石在Na2CO3溶液中有明显膨胀。     

湿法处理钠硅渣回收氧化铝工艺研究

对钠硅渣脱碱后的水化石榴石通入CO₂气体转型的反应进行了热力学分析, 研究了温度、时间、改性次数、Na₂CO₃浓度对转型效果的影响, 并且研究了转型后渣溶铝过程中, 苛性碱浓度、温度、液固比、反应时间对氧化铝溶出率的影响。结果表明: 钠硅渣脱碱后形成的水化石榴石能被CO₂分解, 在分解过程中硅化合物易形成CaO·SiO₂·H₂O、6CaO·6SiO₂·H₂O。反应时间的延长, 适当的反应温度, 有利于提高水化石榴石的转化率, 同时改性处理也可以提高转化率。在溶铝过程中, 时间延长, 液固比提高, 碱浓度升高, 以及适宜的反应温度均可提高溶铝效率。试验最佳工艺条件为: 转型最佳工艺为时间2 h, 液固比5～10, 温度50 ℃, 改性一次; 溶铝最佳工艺为温度50 ℃, 液固比为10, 时间1 h, 碱浓度大于50 g/L, 最优条件下氧化铝溶出率达60%以上, 弃渣中铝硅比A/S小于0.6。     

GPC精铸面砂的应用

由于优质面层材料锆英砂的短缺及其价格的不断上涨,寻找面层错英砂的替代品成为一种必然趋势.主要介绍了采用淮北煤系高岭土开发的精铸面砂,部分替代面层锆英砂在精铸行业上的应用.结果表明,该砂可以用于碳钢、低合金钢以及铝、铜等有色合金和部分不锈钢铸件的生产.     

高碱铝硅酸盐玻璃的研究综述

高碱铝硅酸盐玻璃是一种含铝量高且含碱量也高、并适合于化学强化的高强度玻璃。综合概述了高碱铝硅酸盐玻璃的基本成分、关键生产技术及强化处理,并简单介绍了其应用领域。     

Kinetic frictional behaviour of alumino-silicate ceramics

The frictional behaviour was experimentally investigated of alumino-silicate ceramics (3Al₂O₃, 2SiO₂) rubbing against a hard steel surface under static and kinetic friction conditions. Tests were carried out on a pin-on-disc machine under both dry and wet contact conditions. Results showed that the frictional behaviour under either static or kinetic conditions was highly dependent on the ceramic body phase transformation which in turn was controlled by the firing temperature during ceramic processing and treatment. Lower friction values were evident when using specimens of ceramic bodies containing a high mullite crystalline phase, which are attained at high firing temperatures. Both the running speed and applied loads had insignificant effects at high loads.During kinetic friction tests lower frictional values were displayed than for static friction tests under wet contact conditions, and under dry conditions when using high mullite ceramic bodies. For specimens of ceramics fired at relatively low temperatures, kinetic friction tests produced higher frictional values than static friction tests.