基于团粒法造粒工艺在固相中合成晶体

发布时间：2018-06-04 22:07

本文选题：团粒法 + 固相　；参考：《山西师范大学》2017年硕士论文

【摘要】：本文介绍了一种固相生长晶体的方法,包括直接固相法和间接固相法。该方法建立在化肥造粒的基础上。主要使用团粒法造粒工艺,以腐植酸、蘑菇渣为原料,以石膏作粘结剂,加入其它所需的原料,在溶剂辅助的作用下,研磨并成粒。经过一段时间的放置,晶体在颗粒表面长出。其中,腐植酸、蘑菇渣为晶体生长提供环境,石膏作为粘结剂将物料紧密团聚在一起,溶剂的挥发促进了晶体在固相中的生长,研磨过程辅助了固相中的物料之间发生物理或化学反应。首先,以腐植酸、蘑菇渣、磷酸二氢钠、尿素、石膏为原料制得的化肥颗粒中,经过放置生长出了无色针状的尿素晶体,晶胞参数为a=5.6427?;b=5.6427?,c=4.7168?,α=90°,β=90°,γ=90°,分析了晶体在其中形成的原因,同时讨论了水量和颗粒大小对晶体生长情况的影响。发现腐植酸、蘑菇渣作为生长环境,疏松多孔,为晶体生长提供了通道,而溶剂的挥发为晶体生长提供了牵引力,这些因素共同促进了晶体的生长。此外,当水量适当时,化肥颗粒的硬度较大,形状较规则,生长出的晶体也较长。颗粒直径在4-5 mm左右时,晶体生长的较好。其次,通过间接固相生长方法,以腐植酸、石膏、氟化铵、尿素为原料,在化肥造粒基础上生长得到了硫酸铵晶体,其晶胞参数为a=7.7814?;b=5.9936?,c=10.6484?,α=90°,β=90°,γ=90°,并分析了硫酸铵晶体在固相中生成的原因及晶体的生长情况。发现硫酸铵晶体的形成是由于原料中的硫酸钙和氟化铵发生了化学反应,生成了氟化钙和硫酸铵。腐植酸的疏松结构和硫酸钙的坚固的棒状结构共同组成了蜂窝状的通道结构,供晶体在其中生长。造粒的过程中,物料之间互相挤压产生的机械压力,成为晶体生长的驱动力。此外,在样品袋中下层的固相环境较为稳定,水分蒸发缓慢,因而得到的晶体的质量较上层固相中的好。最后,在不直接提供尿素和氯化铵的情况下,以腐植酸、硫氰酸铵、硫酸铵、尿素、氯化钾、磷酸一铵、石膏为原料,通过间接法固相生长,得到了针状的尿素氯化铵晶体,其晶胞参数为a=7.9177?;b=17.1305?,c=8.0557?,α=90°,β=90°,γ=90°,并对其性质进行了测定。由硫酸铵、硫氰酸铵等提供铵根离子,氯化钾提供氯离子,与尿素分子作用共同形成了尿素氯化铵分子。发现当原料中硫氰酸铵与尿素的物质的量比为1:5时,可以生长出尿素氯化铵单晶。总之,在团粒法造粒工艺的基础上通过直接及间接固相生长得到了尿素晶体、硫酸铵晶体和尿素氯化铵晶体。分别探讨了加入不同原料后晶体在其中形成的原因、过程以及部分条件对晶体生长情况的影响,分析了腐植酸、硫酸钙在晶体生长中的重要性。通过对固相生长机理的探讨,有利于进一步结合固相晶体生长技术生长其它晶体,同时完善该方法的理论体系。
[Abstract]:In this paper, a method of solid phase growth is introduced, including direct solid phase method and indirect solid phase method. The method is based on chemical fertilizer granulation. The granulation process was mainly used, with humic acid and mushroom dregs as raw materials, gypsum as binder, and other necessary raw materials added, which were ground and granulated with the help of solvent. After a period of time, the crystal grows on the surface of the particle. Among them, humic acid and mushroom dregs provide the environment for crystal growth, gypsum acts as binder to agglomerate materials closely, and the volatilization of solvent promotes the growth of crystals in solid phase. The grinding process assists in the physical or chemical reaction between the materials in the solid phase. Firstly, a colorless needle-like urea crystal was grown from fertilizer granules made from humic acid, mushroom dregs, sodium dihydrogen phosphate, urea and gypsum. The cell parameters of the crystal were as follows: a ~ (5.6427) B ~ (5. 6427) C ~ (4) 7168 ~ (8), 伪 ~ (90 掳), 尾 ~ (90) 掳, 纬 ~ (90) 掳. The reason of crystal formation was analyzed. The effects of water content and particle size on crystal growth were also discussed. It is found that humic acid and mushroom dregs as growth environment are porous and provide a channel for crystal growth, while volatilization of solvent provides tractive force for crystal growth. These factors promote crystal growth together. In addition, when the amount of water is appropriate, the hardness and shape of chemical fertilizer particles are larger, and the crystal is longer. When the particle diameter is about 4-5 mm, the crystal grows well. Secondly, ammonium sulfate crystals were obtained from humic acid, gypsum, ammonium fluoride and urea by indirect solid-phase growth on the basis of chemical fertilizer granulation. The cell parameters of the crystal are as follows: a 7.7814 ~ 5.9936 ~ (6) C ~ (10) ~ (6484), 伪 ~ (90 掳), 尾 ~ (90 掳) and 纬 ~ (90) 掳. The reasons for the formation of ammonium sulfate crystal in solid phase and the growth of the crystal are analyzed. It was found that the formation of ammonium sulfate crystal was due to the chemical reaction between calcium sulfate and ammonium fluoride, which resulted in the formation of calcium fluoride and ammonium sulfate. The loose structure of humic acid and the firm rod-like structure of calcium sulfate form honeycomb channel structure for crystal growth. In the process of granulation, the mechanical pressure produced by extrusion between materials becomes the driving force of crystal growth. In addition, the solid environment in the lower layer of the sample bag is stable and the evaporation of water is slow, so the quality of the crystals obtained is better than that in the upper solid phase. Finally, using humic acid, ammonium thiocyanate, ammonium sulfate, urea, potassium chloride, monoammonium phosphate and gypsum as raw materials, the needle-shaped urea ammonium chloride crystal was obtained by indirect solid-phase growth without directly supplying urea and ammonium chloride. The unit cell parameters are 7.9177B ~ (17. 1305) ~ 8.0557H, 伪 ~ (90 掳), 尾 ~ (90 掳) and 纬 ~ (90 掳), and its properties are determined. Ammonium sulfate, ammonium thiocyanate and potassium chloride provide ammonium radical ions, and potassium chloride provides chloride ions, which interact with urea molecules to form urea ammonium chloride molecules. It is found that when the ratio of ammonium thiocyanate to urea is 1:5, the urea ammonium chloride single crystal can be grown. In conclusion, urea crystal, ammonium sulfate crystal and urea ammonium chloride crystal were obtained by direct and indirect solid phase growth on the basis of granulation process. The reason and process of crystal formation and the influence of some conditions on crystal growth after adding different raw materials were discussed. The importance of humic acid and calcium sulfate in crystal growth was analyzed. By discussing the mechanism of solid phase growth, it is advantageous to further combine solid state crystal growth technology to grow other crystals, and to perfect the theoretical system of this method at the same time.
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O78

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