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浅谈水泥用煤外水含量过高对生产的影响
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作者 焦艳红 王明军 +1 位作者 何录君 江超 《科技风》 2008年第14期10-10,共1页
原煤外在水分(Mar)是在开采、运输等过程中附在煤表面和裂隙中的水分,是在一定条件下与周围空气湿度达到平衡时所失去的水分,含外水高的煤粉对生产有很大影响。
关键词 水泥用煤外水含量 生产 处理措施
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水泥用煤燃烧特性评价的实践
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作者 杨德吉 《四川水泥》 2019年第1期6-7,27,共3页
水泥工业中煤的燃烧行为比较复杂,本文通过三十余种烟煤、无烟煤的差热分析试验,从应用的角度,结合本公司水泥工业分解炉炉型的特点,提出了煤的可燃性指数Cb、燃烧稳定性指数G、燃尽特性指数SN和燃烧特性指数等Hj四个评价指标。并引入... 水泥工业中煤的燃烧行为比较复杂,本文通过三十余种烟煤、无烟煤的差热分析试验,从应用的角度,结合本公司水泥工业分解炉炉型的特点,提出了煤的可燃性指数Cb、燃烧稳定性指数G、燃尽特性指数SN和燃烧特性指数等Hj四个评价指标。并引入了评分法对煤炭进行评价,构造了一个相对的可比为本公司水泥工业用煤采购提供了较好的参考。 展开更多
关键词 水泥用煤 可燃性指数 燃烧稳定性指数 燃尽特性指数 燃烧特性指数 燃尽度
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Na_2Cr_2O_7和NaClO_4对水泥窑用煤燃烧特性的影响 被引量:2
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作者 王世杰 吕源 +3 位作者 黄陈杰 秦瑾 刘瑞芝 胡芝娟 《武汉科技大学学报》 CAS 2011年第4期289-292,共4页
以煤的着火点、燃尽点、燃烧烈度、平均放热强度和发热量为评价指标,利用TG-DSC分析添加剂Na2Cr2O7和NaClO4对水泥窑用煤燃烧特性的影响。结果表明,两类燃煤添加剂均能改变水泥窑用煤的燃烧特性。两类添加剂的加入降低了水泥窑用煤燃烧... 以煤的着火点、燃尽点、燃烧烈度、平均放热强度和发热量为评价指标,利用TG-DSC分析添加剂Na2Cr2O7和NaClO4对水泥窑用煤燃烧特性的影响。结果表明,两类燃煤添加剂均能改变水泥窑用煤的燃烧特性。两类添加剂的加入降低了水泥窑用煤燃烧的着火点和燃尽点,使其能够在较低的温度下进行燃烧,提高煤的燃烧性和燃尽性,同时降低了煤的燃烧烈度,使煤的燃烧更加平稳,有利于煤在水泥窑内的燃烧;Na2Cr2O7和NaClO4均能使煤的发热量增加,且加快煤粉热量的释放,促进了煤的完全燃烧。 展开更多
关键词 水泥用煤 添加剂 TG-DSC 燃烧特性
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水泥窑用煤燃烧动力学研究
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作者 王世杰 吕源 +3 位作者 黄陈杰 秦瑾 刘瑞芝 胡芝娟 《武汉科技大学学报》 CAS 2011年第5期373-375,共3页
采用热重分析法对南宁无烟煤在加入催化剂ZnO、NaClO4、Na2Cr2O7、Fe2O3和MnO2前后的燃烧动力学特性进行研究。结果表明,添加的5种催化剂都具有催化效果,但对煤燃烧动力学特性影响程度有所不同;催化剂Na2Cr2O7能改变燃烧反应机理,提高... 采用热重分析法对南宁无烟煤在加入催化剂ZnO、NaClO4、Na2Cr2O7、Fe2O3和MnO2前后的燃烧动力学特性进行研究。结果表明,添加的5种催化剂都具有催化效果,但对煤燃烧动力学特性影响程度有所不同;催化剂Na2Cr2O7能改变燃烧反应机理,提高煤的燃烧速率,更有利于煤的完全燃烧;催化剂能够不同程度地降低煤燃烧的表观活化能,使煤的着火点降低;5种催化剂的催化效果依次为:Na2Cr2O7>NaClO4>ZnO>Fe2O3>MnO2。 展开更多
关键词 水泥用煤 劣质燃烧 催化剂 热分析 动力学参数
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基于灰色关联分析和层次分析法的水泥回转窑用煤质量指标综合评价 被引量:2
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作者 周斌 艾玉强 +1 位作者 费延梅 冯富宁 《水泥工程》 CAS 2020年第5期23-26,31,共5页
本文结合现行国家标准和行业规范,确定水泥回转窑用煤综合评价指标体系和评价指标划分方案,建立基于灰色关联分析和层次分析法(AHP)的水泥回转窑用煤质量等级评价模型,以集团内6家公司进厂煤炭进行综合评价研究。该方法不仅能够反映不... 本文结合现行国家标准和行业规范,确定水泥回转窑用煤综合评价指标体系和评价指标划分方案,建立基于灰色关联分析和层次分析法(AHP)的水泥回转窑用煤质量等级评价模型,以集团内6家公司进厂煤炭进行综合评价研究。该方法不仅能够反映不同级别样本之间的差别,而且还能反映同一级别的样本质量优劣,可用于不同公司或不同供应商之间的煤炭质量综合评价对比,为回转窑用煤使用价值最大化,合理确定进厂验收指标提供决策依据。 展开更多
关键词 灰色关联分析 层次分析法 综合评价 水泥回转窑用煤
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〈水泥回转窑用煤技术条件〉标准修订说明
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作者 张玉昌 刘淑云 《建材标准化与质量管理》 2000年第5期24-25,共2页
关键词 水泥回转窑用煤 标准 修订
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Influence of ultra-fine fly ash on hydration shrinkage of cement paste 被引量:15
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作者 高英力 周士琼 《Journal of Central South University of Technology》 EI 2005年第5期596-600,共5页
Hydration shrinkage generated by cement hydration is the cause of autogenous shrinkage of high strength concrete. It may result in the volume change and even cracking of mortar and concrete. According to the data anal... Hydration shrinkage generated by cement hydration is the cause of autogenous shrinkage of high strength concrete. It may result in the volume change and even cracking of mortar and concrete. According to the data analysis in a series of experimental studies, the influence of ultra-fine fly ash on the hydration shrinkage of composite cementitious materials was investigated. It is found that ultra-fine fly ash can reduce the hydration shrinkage of cement paste effectively, and the more the ultra-fine fly ash, the less the hydration shrinkage. Compared with cement paste without the ultra-fine fly ash, the shrinkage ratio of cement paste reduces from 23.4% to 39.7% when the ultra-fine fly ash replaces cement from 20% to 50%. Moreover, the microscopic mechanism of the ultra-fine fly ash restraining the hydration shrinkage was also studied by scanning electron microscopy, X-ray diffraction and hydrated equations. The results show that the hydration shrinkage can be restrained to a certain degree because the ultra-fine fly ash does not participate in the hydration at the early stage and the secondary hydration products are different at the later stage. 展开更多
关键词 ultra-fine fly ash cement paste hydration shrinkage MECHANISM
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Low-temperature Synthesis of Belite Cement from Reactive Mixtures Based on Coal Fly Ash 被引量:1
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作者 Nadezda Stevulova Ivana Filkova Kestutis Baltakys 《Journal of Civil Engineering and Architecture》 2012年第2期189-196,共8页
This paper summarizes the selected results of an extensive investigation of application of two methods (hydrothermal and mechanochemical) assisted by calcination for synthesizing belite cement from reactive mixtures... This paper summarizes the selected results of an extensive investigation of application of two methods (hydrothermal and mechanochemical) assisted by calcination for synthesizing belite cement from reactive mixtures (CaO/SiO2 molar ratio of 2) consisting of various waste kinds from fluidized brown coal combustion in Slovakian power plant and CaO addition. Based on XRD diffraction patterns and infrared spectra ofpre-treatment products, the formation of the new profiles corresponding to CSH phases with low degree of ordering as belite precursors after hydrothermal treatment as well as metastables calcium silicates and aluminosilicates in mechanosynthesized products was confirmed. Calcination of hydrothermally treated products led to transformation of CSH phases to wollastonite (CS), belite and gehlenite phase, whereas creation oft^- and I^-C2S or wollastonite in milled reactive mixture took place. Differences in phase composition of products before and after calcination depend upon waste quality and precursor's synthesis conditions. Bottom ash isn't suitable as raw material for synthesizing belite phase because of high CaO content fixed in anhydrite form (44.1%). Coal fly ash with low CaO content in anhydrite form (4.2%) and its mechanochemical or hydrothermal treatment in combination with subsequent heating offer opportunities for the utilization of coal fly ash as raw material for belite production. 展开更多
关键词 Coal fly ash hydrothermal pre-treatment MECHANOSYNTHESIS belite.
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Effective Utilization of Coal Fly Ash in Building Material Production
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作者 Jozef Junak Nadezda Stevulova 《Journal of Chemistry and Chemical Engineering》 2011年第8期724-728,共5页
This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power pla... This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power plant in Novsky (Si/Al = 3,1) as a partial cement replacement in concrete on compressive strength of hardened composites after 28 and 90 days was investigated. Alkaline activation of coal fly ash was realized in an autoclave at 130 ℃ and pressure of 160 kPa during 5 hours and in a reactor under normal conditions (equal temperature during 36 hours) at solid/liquid ratio of 0.5. Coal fly ash/cement mixtures were prepared with 25 % cement replacement by starting and modified coal fly ash and given in forms. Compressive strengths of composites after 28 and 90 days of hardening were compared to referential composite without coal fly ash and evaluated according to the standard of STN EN 450 by the value of relative strength KR (compressive strength of coal fly ash/cement composite to compressive strength of comparative concrete). The final compressive strengths of hardened composites based on alkaline activated coal fly ash reached values in the range of 6 up to 50 MPa. In the set of experimental composites based on alkaline activated coal fly ashes, the highest value of relative strength after 28- and 90- days of hardening reached composite with cement replacement by coal fly ash zeolitized in autoclave (105% of compressive strength of referential sample), what is connected with formation of zeolitic phases on surface of coal fly ash particles. The achieved results confirm that alkaline activation of coal fly ash in an autoclave under observed conditions can be successfully used as a partial cement replacement in concrete of C20/25 and C25/30 in accordance with requirements of standards (STN EN 450 and STN EN 206). 展开更多
关键词 coal fly ash chemical activation CONCRETE compressive strength ZEOLITE
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