天然石膏对钛石膏的模拟试验及其改性研究

发布时间：2018-06-06 16:32

本文选题：钛石膏 + 天然石膏　；参考：《济南大学》2015年硕士论文

【摘要】：钛石膏作为一种替代天然石膏的石膏资源,是一项宝贵财富,虽然在水泥缓凝剂及轻质墙体材料中得到了一定应用,但是由于其水化活性比较差,强度难以被激发而被当作垃圾处理,成为应用程度最小、应用范围最窄的工业副产石膏。本课题基于形态组成模拟法,探索导致钛石膏标稠用水量大、力学强度低的原因,并在此基础上,采用物理、化学两种改性方法激发钛石膏活性,改善钛石膏物理性能,将其应用于建材领域,为进一步促成钛石膏的资源化应用开拓新途径。采用粒度分析仪、X射线荧光光谱仪等仪器研究了天然石膏与钛石膏的物理形态与化学组成的区别。测试结果表明,钛石膏的粒径分布范围相对天然石膏要窄,平均粒径比天然石膏小;钛石膏中Fe、Al、Si等杂质元素含量均高于其在天然石膏中含量,尤其是钛石膏中Fe元素含量比天然石膏要大得多;钛石膏与天然石膏的物理性能差别较大,其中钛石膏的标稠用水量是天然石膏的2.57倍,凝结时间明显偏长,2h力学强度极小,根本无法达到GB/T 9776-2008《建筑石膏》的标准要求。通过控制粉磨所用时间,得到粉磨石膏系列,经粒度分析发现,粉磨时间为40min的试样比表面积、平均粒径以及颗粒级配情况和钛石膏基本一致,达到形态模拟钛石膏(以下简称MTG)的状态;MTG的标稠用水量相对于天然石膏略有增加,但其仅为钛石膏标稠用水量的3/5;同时,MTG的初、终凝时间相对于天然石膏分别延长了6min、8min,但比钛石膏的初、终凝时间分别短了14min、24min;MTG的2h抗折抗压强度相对于天然石膏分别降低了31.27%以及13.87%,但是仍与钛石膏存在明显差距,其2h抗折抗压强度分别比钛石膏高198.15%、134.78%。这表明石膏物理形态对石膏水化硬化体的物理性能存在一定影响,但其并非导致钛石膏性能差的决定性因素。在MTG的基础上,依次递加2.69%二氧化硅、1.23%氧化铝、13.01%氧化铁以及17.39%氢氧化铁得到化学组成模拟钛石膏(以下简称CTG)。试验结果表明,依次掺加二氧化硅、氧化铝、氧化铁并未引起试样物理性能明显变化,而氢氧化铁掺加到MTG中,试样的物理性能发生显著变化。单掺氢氧化铁时,MTG的物理性能亦发生了显著变化。氢氧化铁掺量为17.5%时,试样的标稠用水量为149.8%,初终凝时间分别为27min、55min,2h抗折、抗压强度分别为0.295MPa以及0.759MPa,与钛石膏的物理性能基本一致,由此判断导致钛石膏物理性差的因素是氢氧化铁。针对影响因素对钛石膏进行了物化激发,实验结果表明,钛石膏的最佳煅烧温度为180℃,此时试样的标稠用水量相对于100℃煅烧的试样下降了15.8%,初终凝时间分别缩短了27min、39min;2h抗折抗压强度分别为0.46MPa、0.91MPa。经酸洗改性,钛石膏试样的标稠用水量、初终凝时间、2h抗折抗压强度均发生明显改善,其中标稠用水量降低了10.73%,初终凝时间分别缩短了30.43%、19.61%,2h抗折抗压强度分别提高了21.96%、70.20%。萘系减水剂对钛石膏的减水效果最好,其最佳掺量为3.0%。经正交实验确定了复配激发剂的最佳配比为:硫酸钠0.5%、生石灰2.5%、激发剂K1.5%,此时钛石膏试样的物理性能指标如下:标稠用水量80.2%,初终凝时间分别为4min、10min,2h抗折抗压强度分别为1.63MPa、3.17MPa,基本达到GB/T 9776-28《建筑石膏》的标准要求。最后,研究制备了钛石膏发泡材料,研究了双氧水、稳泡剂H以及复合防水剂对钛石膏发泡材料性能的影响,确定了其最佳原料配比为:双氧水5%,稳泡剂H4%,复合防水剂2%,此时钛石膏发泡材料的物理指标如下:密度234kg/m3、导热系数0.065W/(m·K)、抗折抗压强度分别为0.23MPa、0.43MPa、吸水率9.5%,均能满足《山东省建筑外墙用无机保温板性能指标要求》的技术要求。
[Abstract]:As a kind of gypsum resources replacing natural gypsum, titanium gypsum is a valuable asset. Although it has been used in cement retarder and light wall material, it has been used as waste treatment because of its poor hydration activity and hard to be stimulated. This is the industrial byproduct with the smallest application range and the narrowest application range. Based on the form composition simulation method, the cause of high water consumption and low mechanical strength of titanium gypsum is explored. On this basis, two modified methods of physical and chemical modification are used to stimulate the activity of titanium gypsum, improve the physical properties of titanium gypsum, and apply it to the field of building materials, and exploit a new way to promote the resource application of titanium gypsum. The difference between physical form and chemical composition of natural gypsum and titanium gypsum is studied by means of particle size analyzer, X ray fluorescence spectrometer and other instruments. The test results show that the size distribution range of titanium gypsum is narrower than that of natural gypsum, and the average particle size is smaller than that of natural gypsum, and the content of impurity elements, such as Fe, Al, and Si in titanium gypsum, is higher than that in natural gypsum. Content, especially the content of Fe element in titanium gypsum is much larger than that of natural gypsum; the physical properties of titanium gypsum and natural gypsum have great difference, and the thick water amount of titanium gypsum is 2.57 times of the natural gypsum, the setting time is obviously long, the mechanical strength of 2H is very small, and the standard requirement of the GB/T 9776-2008< building gypsum can not be reached. Through control, it is controlled by control. The pulverizing mill was used for grinding the gypsum series. The particle size analysis showed that the specific surface area, the average particle size and the grain gradation were basically the same as the titanium gypsum, and the morphology simulated the state of the titanium gypsum (hereinafter referred to as MTG). The consistency of the MTG was slightly higher than that of the natural gypsum, but it was only 40min. At the same time, the initial setting time of MTG is longer than that of natural gypsum, while the initial setting time of the paste is 6min and 8min, respectively, but 14min and 24min are shorter than that of the titanium gypsum, and the compressive strength of 2h in MTG is reduced by 31.27% and 13.87%, respectively, compared with the natural gypsum, but there is still a significant difference with the titanium gypsum, and its 2H anti folding and anti compression strength is still available. The degree of 134.78%. is 198.15% higher than that of titanium gypsum, which indicates that the physical form of gypsum has a certain effect on the physical properties of the gypsum hydrated hardened body, but it is not the decisive factor that leads to the poor performance of the titanium gypsum. On the basis of MTG, the chemical group is obtained by adding 2.69% silica, 1.23% alumina, 13.01% iron oxide and 17.39% ferric hydroxide. The simulated titanium gypsum (hereinafter referred to as CTG). The experimental results show that the physical properties of the sample have not been obviously changed by adding silica, alumina and iron oxide in turn, but the physical properties of the sample have changed significantly in the addition of iron hydroxide to MTG. The physical properties of MTG have also changed remarkably when the iron hydroxide is mixed with iron hydroxide. At 17.5%, the thick water consumption of the sample is 149.8%, the initial setting time is 27min, 55min, 2h, and the compressive strength is 0.295MPa and 0.759MPa respectively. The physical properties of the titanium gypsum are basically the same, thus judging that the physical poor factor of the titanium gypsum is ferric hydroxide. The results show that the optimum calcining temperature of titanium gypsum is 180 C, at this time the viscosity of the sample is reduced by 15.8% compared with the sample calcined at 100, and the initial setting time is shortened by 27min and 39min respectively. The flexural compressive strength of 2H is 0.46MPa, 0.91MPa. is modified by acid washing, the thick water content of the titanium gypsum sample, the initial end setting time, and the anti compression strength of 2H. The water quantity of the standard thickening was reduced by 10.73%, the initial setting time was reduced by 30.43% and 19.61%, and the flexural compressive strength of 2H was increased by 21.96% respectively. The effect of 70.20%. naphthalene water reducing agent on the water reduction of titanium gypsum was best, and the optimum mixing amount of 3.0%. was confirmed by orthogonal experiment: sodium sulfate 0.5%. Lime 2.5%, activator K1.5%, at this time the physical properties of the titanium gypsum samples are as follows: the standard water consumption is 80.2%, the initial setting time is 4min, 10min, and 2H is 1.63MPa, 3.17MPa, respectively, and basically meets the standard requirement of GB/T 9776-28< building gypsum >. Finally, the titanium gypsum foam material is prepared, and the hydrogen peroxide and stable bubble are studied. The effect of H and compound waterproof agent on the properties of titanium gypsum foam material is determined. The optimum raw material ratio is: hydrogen peroxide 5%, foam stabilizer H4% and compound waterproof agent 2%. At this time, the physical indexes of the titanium gypsum foam material are as follows: density 234kg/m3, thermal conductivity 0.065W/ (M. K), compressive strength of 0.23MPa, 0.43MPa, and water absorption 9.5%, respectively. Foot "technical requirements for the performance requirements of inorganic insulation board for building exterior walls in Shandong".
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ177.37

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