BaO对磷铝酸盐水泥合成及性能的影响

发布时间：2018-02-22 08:31

  本文关键词： BaO 磷铝酸钙 铝酸钙 高铁磷铝酸盐水泥 含钡磷铝酸盐水泥　出处：《济南大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文主要研究了BaO对磷铝酸盐水泥合成及性能的影响,通过掺杂Ba2+离子部分取代Ca2+离子,增加磷铝酸盐水泥矿相微结构缺陷,优化熟料矿物组成,提高其水化活性,以期制备出具有良好力学性能的含钡磷铝酸盐水泥熟料。主要从以下几个方面开展研究:将BaO引入到磷铝酸钙和铝酸钙矿物中,使其晶格产生畸变,调节矿物微结构,进一步提高矿物的水化活性;制备高铁磷铝酸盐水泥熟料,研究氧化铁对磷铝酸盐水泥熟料矿相低温形成的影响规律;以单矿物中BaO的掺量研究为基础,将BaO引入高铁磷铝酸盐水泥熟料,获得具有良好性能的含钡磷铝酸盐水泥熟料。主要研究结论如下:(1)掺入适量的BaO,磷铝酸钙矿物的各龄期抗压强度均有所提高。其最佳掺量为20%(摩尔掺量,BaO取代Ca O量)。在最佳掺量条件下,该矿物3d、28d、90d抗压强度分别达到了60.0MPa,109.3MPa和122.7MPa。分别比空白样提高了38.5%,26.0%和18.2%。(2)BaO的掺入使得磷铝酸钙矿物水化明显加快,7d的水化程度达到90%以上,且更容易生成稳定的水化产物C(A,P)H10;磷铝酸钙的水化产物的形态由板状转变为薄片状,且水化产物尺寸更小,大约在2μm~5μm,这使得矿物水化产物相互搭接更为紧密,形成更密实的硬化浆体结构;孔结构分析结果表明,含钡磷铝酸钙矿物的硬化浆体有害孔含量与空白样相比大大降低。(3)掺加BaO可增加CA合成过程中的液相量,减少中间产物C12A7的量;当BaO掺量为7%(摩尔掺量,Ba O取代CaO量)时,试样具有较好的抗压强度;Ba2+离子的引入可稳定CAH10晶格,阻止CAH10向C3AH6的晶型转变,防止后期强度倒缩;随着Ba2+离子掺量的增加,水化产物CAH10最大分解速率温度逐渐增加,水化产物热稳定性提高;CA结构中BaO的最大容纳量为15%,超出该掺量后将出现气硬性矿物BA的衍射峰。(4)高铁磷铝酸盐水泥熟料中Fe2O3最佳含量为11%(质量分数),当煅烧温度为1350℃。该试样1d强度可达70.6MPa,28d强度达到95.5MPa;相应的熟料氧化物质量组成范围为Al2O3 25.0~32.0%,CaO 30.0~40.0%,P2O5 14.0~15.0%,SiO23.0~5.0%,Fe2O3 10.5~11.0%。Fe2O3可以作为磷铝酸盐水泥烧成过程中的一个重要组分,在较低的温度下促进矿物CA1-Y(PY)向特征矿物LHss的转变,调整高铁磷铝酸盐水泥矿物组成;铁相处在主要熟料矿物的间隙中,是一系列固溶体,没有固定的化学组成。(5)含钡高铁磷铝酸盐水泥熟料中BaO最佳掺量为11%(摩尔掺量,BaO取代CaO量),Fe2O3最低掺量为7%(质量分数),最佳煅烧温度为1420℃,相应的熟料氧化物质量组成范围为Al2O3 25.0~32.0%,CaO 30.0~37.0%,BaO 10.5~11.0%,P2O514.0~15.0%,SiO2 3.0~5.0%,Fe2O3 6.0~7.5%。其1d强度为106.5MPa,28d强度达到了143.2MPa;与高铁磷铝酸盐水泥相比,其1d、3d、7d和28d强度分别增长了50.8%、21.0%、27.0%和49.9%。
[Abstract]:In this paper, the effect of BaO on the synthesis and properties of phosphoaluminate cement was studied. By partially replacing the Ca2 ion with Ba2 ion, the microstructural defects of Phosphoaluminate cement were increased, the mineral composition of clinker was optimized and its hydration activity was improved. In order to prepare barium phosphoaluminate cement clinker with good mechanical properties, the following aspects were studied: introducing BaO into calcium aluminate phosphate and calcium aluminate minerals, resulting in lattice distortion and adjusting mineral microstructure, To further improve the hydration activity of minerals, to prepare ferric aluminate cement clinker, to study the influence of ferric oxide on the formation of mineral phase at low temperature, based on the study of the content of BaO in single mineral, BaO was introduced into high iron phosphoaluminate cement clinker, Barium phosphate aluminate cement clinker with good properties has been obtained. The main conclusions are as follows: 1: 1) the compressive strength of calcium aluminophosphate minerals at all ages has been improved with the addition of appropriate amount of Bao. The optimum addition amount is 20% (mol amount of Bao instead of Ca). Under the optimum dosage condition, The compressive strength of the mineral reached 60.0 MPA 109.3 MPA and 122.7 MPA, respectively. The addition of 38.5% and 18.20.2mBaO increased the hydration of calcium aluminophosphate to more than 90%, respectively, compared with the blank sample, and the compressive strength of the mineral reached 60.0MPA 109.3 MPA and 122.7 MPa respectively, which increased the hydration of calcium aluminophosphate by 38.5% and 18.2% respectively, and increased the hydration degree of calcium aluminophosphate to more than 90% in 7 days. It is easier to form a stable hydration product, CnAH10, and the form of hydration product of calcium aluminate aluminophosphate changes from plate to sheet, and the size of hydration product is smaller, which is about 2 渭 m ~ 5 渭 m, which makes the mineral hydration products overlap more closely with each other. The results of pore structure analysis showed that the harmful pore content of hardened paste containing barium phosphate calcium aluminate mineral was much lower than that of blank sample. Addition of BaO could increase the amount of liquid phase in the process of CA synthesis. When the content of the intermediate product C _ (12) A _ 7 is reduced, when the content of BaO is 7% (CaO is replaced by Ba _ (O)), the CAH10 lattice can be stabilized by the introduction of Ba _ (2) ion, which can prevent the transition of CAH10 to the crystal form of C _ (3AH _ 6) and prevent the later strength from collapsing. With the increase of Ba2 ion content, the maximum decomposition rate temperature of hydration product CAH10 increases gradually. The thermal stability of hydration products improves the maximum holding capacity of BaO in CA structure is 15. The diffraction peak of gas-hard mineral BA will appear when the content exceeds this amount.) the optimum content of Fe2O3 in high iron phosphoric aluminate cement clinker is 11 (mass fraction, when calcined temperature is high). The strength of the sample can reach 70.6 MPA / 28d in 1 day at 1350 鈩，

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