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微絮凝—超滤工艺处理黄河水的试验研究 总被引:3,自引:2,他引:1
采用微絮凝—超滤工艺处理黄河水,考察了其对污染物的去除效果。结果表明:微絮凝—超滤工艺对浊度和病原微生物有较好的去除效果,出水浊度〈0.1NTU的保证率可达到95.26%,对总大肠菌群和细菌总数的去除率分别达到了100%和99.7%以上;对UV254的去除效果一般,平均去除率为14.9%。微絮凝—超滤工艺对CODMn的去除效果受进水CODMn的影响较大,当进水CODMn为3.6~4.5mg/L时,出水CODMn〈3.0mg/L;但当进水CODMn为4.6~5.9mg/L时,出水CODMn〉3.0mg/L,不能满足《生活饮用水卫生标准》(GB5749--2006)的要求。 相似文献
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白俄罗斯的科研人员为研究某些添加剂对瓷器白度的影响,使用了如下重量含量的日用瓷生产坯料:高岭土42%、粘土7%、伟晶岩18%、石英砂25%、氧化铝2%,另外6%是二次烧成之后的制品渣。在这100%之外引入0.5%~2%的添加剂,还引入了碳酸钠和水玻璃。据报道,当加入三聚磷酸钠时,瓷器白度提高3%~5%,加入ZrO_2和ZrSiO_4时白度提高 相似文献
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改性氨基磺酸系高效减水剂的研究 总被引:5,自引:1,他引:5
氨基磺酸系高效减水剂ASP具有减水率高、坍落度损失小等特点,但其价格较高、混凝土易泌水离析,限制了其工程应用。将氨基磺酸的聚合物与木质素磺酸盐进行接枝共聚,研制出改性氨基磺酸秉高效减水剂ASM。可使生产成本降低20%。试验研究了ASM对水泥砂浆和混凝土性能的影响,结果表明,水灰比为0.26时,掺ASM的水泥净浆流动度达到248mm,120min后的净浆流动度损失率为12.1%,可满足低水灰比下配制混凝土的需要。掺0.5%ASM的水泥净浆凝结时问比同掺量ASP分别缩短100min~150min。可延缓水泥的初期水化。推迟水泥水化放热峰的出现约16h。掺0.5%ASM的砂浆泌水率由ASP的12.4%下降到1.4%,其保水性能有较大的提高,解决了氨基磺酸系减水剂离析泌水现象。ASM的减水串达到21.9%~26.3%。高于同掺量下ASP的减水率。掺ASM的混凝土2h后坍落度损失仅为13。4%~15.9%,28d混凝土的抗压强度均大于70MPa,达到了高强混凝土的要求。 相似文献
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以磷石膏为原料生产β半水石膏粉,研究了可溶性无水 AⅢ对半水石膏粉的影响,采用常规分析方法、TG-DSC、XRD 和扫描电镜等方法对磷石膏原料,β半水石膏粉和石膏产品进行分析和表征。差热分析结果表明:磷石膏低温脱水出现两个 DSC 吸热峰,峰值仅相差6℃并存在重叠现象,说明脱水反应分两步进行,发生了不同反应,熟石膏粉中存在不同相混合物。半水石膏粉煅烧最佳工艺:焙烧温度在170±5℃内,焙烧时间2 h,熟石膏新粉结晶水含量约3.0%,通过陈化,控制结晶水含量4.8%~5.2%,有利于提高熟石膏粉质量。半水石膏水化热效应结果表明:AⅢ活性高,水化速度快,导致添加减水剂时几乎未见减水增强效果,说明 AⅢ影响熟石膏粉质量。陈化粉添加减水剂能提高石膏制品强度,聚羧酸系 HC 掺量0.7%时,绝干强度达到15.0 MPa,强度提高近64.84%;奈系 FDN 掺量0.7%时,绝干强度达到14.8 MPa,强度提高近62.64%;木质素减水剂掺量0.7%时,绝干强度达到13.9 MPa,强度提高近52.75%。 相似文献
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在实验室条件下,以废玻璃、氢氧化钠、粉煤灰或高炉矿渣为主要原料先制取碱玻璃胶凝材料,然后将此材料在540~570℃下膨胀,可以制得一种新的人造轻骨料、其松散密度为342~569kg/m^3,颗粒密度为670~1011kg/m^3,筒压强度为0.75~2.10MPa、24h吸水率为4.5%~10.1%,软化系数为0.72~0.78,SO3含量为0.3%,Cl含量为0.2%。 相似文献
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G.D. Ransinchung Brind Kumar Veerendra Kumar 《Construction and Building Materials》2009,23(2):1168-1177
Wollastonite with or without microsilica was evaluated as a new material for partial replacement of cement in M40 grade pavement quality concrete. Wollastonite is abundantly available in the Udaipur belt of Rajasthan state in the Indian union as a low cost material. Its physical and chemical properties were analyzed. This particular wollastonite consists of 45.6% of CaO and 48% of SiO2, mainly in amorphous form and has an average specific surface area of 842.7 m2/kg. Five finalized concrete mix proportions including the control mix were investigated for saturated water absorption, rate of water absorption, coefficient of water absorption and chloride ion penetration. Test results indicate that up to 15% of wollastonite and 7.5% microsilica can be advantageously admixed with cement to significantly improve the water tightness of concrete due to reduction in pore space and refinement of microstructure. Mathematical relationships existing between these parameters were studied and predictive graphs were developed. 相似文献
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提出了混凝土实现高性能化的基本技术途径,着重研究了粉煤灰、矿渣、硅灰的单掺对轻集料混凝土强度的影响,得出了硅灰对轻集料混凝土强度的贡献比矿渣和粉煤灰的大,并对硅灰的作用机理进行了探讨,以促进高性能混凝土的研究。 相似文献
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湖北某石墨矿属结晶片岩石墨矿床,其尾矿主要矿物组成为长石、石英、透辉石、透闪石,其次为云母、绿泥石、方解石、黄铁矿等;平均粒度为0.14mm,-200目含量为13.84%,以细粒为主,粘性粒级含量低,含水为2.52%,容重为1.7g/cm3。利用石墨矿尾矿、普通水泥、起泡剂等材料制备泡沫混凝土,试验结果表明:其性能完全达到《泡沫混凝土砌块》(JC/T 1062-2007)中密度等级为B08、强度等级为A3.5的要求。 相似文献
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无水硫酸钙在食品中可以作为稳定剂、凝固剂等,用途十分广泛。虽然国家有强制执行标准GB1892-2007,但只规定了含量等相关要求,并没有对生产工艺进行明确的规定,而这两种工艺煅烧生产的无水硫酸钙在本质上又有区别,为了对比两种工艺的优劣,本文简单介绍了无水硫酸钙的现代煅烧工艺和传统煅烧工艺,选择了有代表的两种煅烧工艺的无水硫酸钙,表征了其微量元素含量、pH值、白度、气味、杂质、干燥减量和稳定性能。结果表明,现代工艺生产的无水硫酸钙各项指标均优于传统工艺,更能满足食品添加剂的要求。 相似文献
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Youngil Cho Charles T. Driscoll Joel D. Blum 《The Science of the total environment》2009,407(20):5392-5401
Patterns of storm runoff chemistry from a wollastonite (calcium-silicate mineral, CaSiO3) treated watershed (W1) were compared with a reference watershed (W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire (NH), USA to investigate the role of Ca2+ supply in the acid–base status of stream chemistry. In the summer of 2003, six storm events were studied in W1 and W6 to evaluate the effects of the wollastonite treatment on the episodic acidification of stream waters. Although mean values of Ca2+ concentrations decreased slightly from 33.8 to 31.7 μmol/L with increasing stream discharge in W1 during the events, the mean value of acid neutralizing capacity (ANC) was positive (1.2 μeq/L) during storm events, compared to negative values (− 0.2 μeq/L) in W6. This pattern is presumably due to enhanced Ca2+ supply in W1 (20.7 to 29.0% of dissolved Ca2+ derived from the added wollastonite) to stream water as a result of interflow along shallow flowpaths. In addition, the application of wollastonite increased pH and dissolved silica (H4SiO4) concentrations, and decreased the concentration of inorganic monomeric Al (Ali) in W1 in comparison with W6 during storm events. Despite an increase in SO42− concentration, likely due to desorption of sulfate from soil after the treatment, the watershed showed an increase in ANC compared to the reference watershed, serving to mitigate episodic acidification. 相似文献