Utilisation of high volumes of limestone quarry wastes in concrete industry (self-compacting concrete case)

In limestone quarries, considerable amounts of limestone powders are being produced as by-products of stone crushers. High amounts of powders are being collected and utilisation of this by-product is a big problem from the aspects of disposal, environmental pollution and health hazards. In conventional concrete, the introduction of high volumes of limestone quarry dust to concrete mixes is limited due to its negative effects on water demand and strength of concrete. However, these fines can be efficiently utilised as viscosity enhancer particularly in special concrete (like self-compacting concrete—SCC) applications. Thus, the successful utilisation of this quarry dust in SCC could turn this material into a valuable resource.In this paper the usability of a quarry dust limestone powder in self-compacting paste and concrete applications was investigated. In the first part, the physical and mechanical properties of cement pastes incorporating quarry waste limestone powder (QLP) and a powder produced by direct grinding of limestone (PLP) were compared. In the second part, the performance of quarry waste limestone powder in SCC applications were tested and discussed. Results showed that, it is possible to successfully utilise high amounts of quarry waste limestone powder in producing normal-strength SCCs. Among its observed mechanical advantages, employment of quarry waste limestone powders improved the economical feasibility of SCC production.     

石灰石湿法烟气脱硫试验研究

介绍了湍球塔石灰石湿法烟气脱硫系统，通过试验，研究分析了床层阻力，脱硫效率，ＣａＣＯ３利用率等因素，试验证明烟气脱硫的效率可达５０％￣８５％，是一种简易的烟气脱硫方法。     

湿法烟气脱硫用石灰石溶解数学模型研究

石灰石／石膏湿法烟气脱硫是我国广泛应用的脱硫技术,其中石灰石活性对优化脱硫装置的设计,降低脱硫成本．提高脱硫效率显得尤为重要。通过实验对石灰石活性进行了研究,在固定pH值的条件下,采用酸滴定石灰石浆液的方法．研究了不同pH值以及Cl-对石灰石溶解率的影响。结果表明,在所测的pH值范围内,较低的pH值有利于石灰石的溶解,pH值每降低0．5,石灰石的溶解率增加8％左右。但为了保持吸收溶液的脱硫效果,一般选择pH值在5．0．5．5之间。Cl-阻碍石灰石的溶解,Na^＋促进石灰石的溶解,且pH值越高作用越明显。此外,建立了石灰石溶解的数肇模型并与实验结果进行了比较．得到了较好的相似性。     

腐殖酸钠在湿法石灰石烟气脱硫系统中阻垢性能的研究

介绍了腐殖酸钠(HAS)的阻垢机理,研究了HAS在石灰石湿法烟气脱硫系统中的阻垢效应,同时在相同的条件下与己二酸的阻垢效果作了对比实验.结果表明,HAS对pH在5.5～6.5、质量分数为3.5%的石灰石脱硫浆液有很好的缓冲作用;并在此浓度的脱硫浆液中,质量浓度为1.5g/L的HAS的阻垢效果达到最佳.石灰石浆液中挂片上的结垢量对比实验得出,添加最佳浓度己二酸时的结垢量,只比添加最佳浓度HAS时的结垢量平均少1.8×10-4g/cm2.     

山东省石灰岩山地的适生树种资源

本文简述了山东省石灰石岩山地的概况，列出了山东省石灰岩山地的适生树种名录，编制了分类检索表，提出了加速瘠薄山地绿化的建议和措施。     

以石灰石和石灰为脱硫剂的镁强化FGD过程对比研究

目前石灰石和石灰仍是湿式烟气脱硫(FGD)的2种主要脱硫剂。因二者物理性质不同，其利用率和脱硫率等随操作参数的变化规律亦有差异。为了分析这种差异，依据旋流板塔镁强化石灰石／石灰FGD实验结果，研究得出了脱硫率等随操作参数变化的拟合方程，计算了不同浆液pH值下石灰石和石灰的利用率，对比分析了相关方程的导数。结果表明，镁强化石灰FGD过程的脱硫率因入口气体SO2浓度的增大而下降的幅度小于镁强化石灰石的过程；在设备条件等相同的情况下，为实现高效净化，镁强化石灰石FGD过程的操作液气比大于镁强化石灰的过程；石灰的利用率随浆液pH值的降低而提高的幅度较小，而在保证脱硫率的前提下，降低操作pH值则可有效提高石灰石的利用率。     

石灰石还原态脱硫中各阶段物料的热重和电镜分析研究

阐述了石灰石还原态脱硫时硫化、氧化过程的热重分析研究结果，并通过数学处理给出了各自的动力学方程；对颗粒各阶段微孔结构的电镜分析，得出了硫化过程不会发生孔闭塞现象，可以在较低石灰石用量的前提下，获得高的脱硫效率。     

石灰石-石膏湿法脱硫废水的产生和处理工艺

本文论述了燃煤电厂石灰石-石膏法湿法脱硫技术脱硫废水的来源、水质和产生量,分析了脱硫废水处理的工艺、原理,并提出了脱硫废水的合理综合利用途径。