【摘要】： 本文采用冷凍干燥法,以制備高品質(zhì)超細(xì)碳酸氫鈉為目標(biāo),研究了冷凍干燥法制備超細(xì)碳酸氫鈉的可行性及其工藝規(guī)律,并在此基礎(chǔ)上開(kāi)展了優(yōu)化工藝參數(shù)、提高凍干效率的工藝探索。 本文通過(guò)三個(gè)重要步驟：前驅(qū)液體溶液制取、溶液凍結(jié)和凍結(jié)物冷凍干燥,得到了超細(xì)的碳酸氫鈉粉體。采用XRD、激光粒度儀、SEM對(duì)所制粉體性能進(jìn)行了分析和表征,結(jié)果表明采用冷凍干燥法所制得的粉體粒徑小而均勻、粒度分布狹窄、粒子間團(tuán)聚少、分散性好,且其晶化程度都有一定程度的降低。 在實(shí)驗(yàn)中采用了直接冷凍、真空蒸發(fā)冷凍和噴霧冷凍三種冷凍方式。噴霧冷凍得到的粉體粒徑最小,為2.26um,其中噴射壓力對(duì)碳酸氫鈉粉體的粒徑影響最大,溶液濃度次之。研究發(fā)現(xiàn),高的凍結(jié)速率、低的前驅(qū)體溶液濃度有利于制備顆粒尺寸更為細(xì)小的粉體。 此外,本文研究了工藝條件對(duì)冷凍干燥效率的影響。研究結(jié)果表明,凍結(jié)速率越高、物料厚度越薄、物料升華面積越大則單次干燥越快,耗時(shí)越短,其中物料厚度對(duì)干燥速率的影響較為顯著；在前驅(qū)體溶液中加入5%的叔丁醇可改變?nèi)軇┑慕Y(jié)晶形態(tài),有效加快干燥速率。
[Abstract]:In this paper, the freeze-drying method was used to prepare ultrafine sodium bicarbonate as the target. The feasibility and technological rules of preparing ultra-fine sodium bicarbonate by freeze-drying method were studied, and the technological parameters were optimized. Exploration of improving freeze-drying efficiency. In this paper, ultrafine sodium bicarbonate powder was obtained by three important steps: preparation of precursor liquid solution, freezing of solution and freeze-drying of frozen substance. The properties of the powders were analyzed and characterized by XRD, laser granularity analyzer and SEM. The results show that the powders prepared by freeze-drying method have small and uniform particle size, narrow particle size distribution, less agglomeration between particles and good dispersion. The degree of crystallization is decreased to some extent. Direct freezing, vacuum evaporation and spray freezing were used in the experiment. The particle size of the powder obtained by spray freezing is the smallest, which is 2.26 um.The spray pressure has the greatest influence on the particle size of sodium bicarbonate, followed by the concentration of solution. It was found that high freezing rate and low concentration of precursor solution were beneficial to the preparation of smaller powders. In addition, the effect of technological conditions on freeze-drying efficiency was studied. The results show that the higher the freezing rate, the thinner the material thickness, the bigger the material sublimation area, the faster the drying time is and the shorter the time is, and the more significant the effect of material thickness on drying rate is. The addition of 5% tert-butanol to the precursor solution can change the crystal morphology of the solvent and accelerate the drying rate effectively.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2010
【分類號(hào)】：TB383.3

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李菲;劉義;趙東風(fēng);林浩然;;反溶劑重結(jié)晶法制備超細(xì)碳酸氫鉀粉體[J];現(xiàn)代化工;2012年04期

相關(guān)碩士學(xué)位論文 前1條

1 余紅燕;凍干機(jī)控制系統(tǒng)的研究與設(shè)計(jì)[D];江西理工大學(xué);2012年

，

本文編號(hào)：2399696