磷酸结晶介稳区性质的研究

一、水垢的成因工业锅炉以及家庭用的烧水壶，使用一段时间后在金属表面就会结成水垢，这是由于水中溶有一定数量的钙镁盐类，如碳酸氢盐、碳酸盐、硫酸盐、氯化物、硅酸盐、磷酸盐等同的还含有泥沙和有机物等。

这些盐类在受热过程中发生物理和化学变化而形成水垢。

水中含有的碳酸氢钙在水温升高过程中会分解生成难溶的碳酸钙：Ca(HCO3)2==△==CaCO3+C02↑+H20碳酸氢镁也会分解生成碳酸镁，它在水中不稳定会转化成溶解度更小的氢氧化镁沉淀，因此水垢中还含有少量氢氧化镁。

在碱性条件下，碳酸氢钙会发生如下反应生成碳酸钙：Ca(HCO3)2+20H1-====CaCO3+2H2O+CO2-3此时，如水中含有较多的氯化钙时也会发生如下的生成碳酸钙的沉淀：CaCl2+C02-3====CaCO3↓+2C1-当水中溶有过量的磷酸盐时，氯化钙也会转化成溶解度很小的磷酸钙。

2P03-4+3CaCl2--Ca3(PO4)2↓+6Cl-通常水垢的主要成分是碳酸钙和磷酸钙。

水中还溶解有一定数量的硫酸钙；硅酸钙等其他无机盐类，随着水的蒸发，它们在水中浓度加大，当其浓度超过溶解度之后也会生成沉淀，并沉积在传热表面上。

在工业锅炉中金属表面的铁锈和铜锈等锈垢也会转化成水垢的成分。

由于水垢大都由无机盐组成，故称为无机垢，而且这些水垢结晶致密，比较坚硬，所以又称为硬垢。

实际水垢的成分相当复杂而且成分随着水质情况的不同而变化，所以对不同地区的水垢应作具体分析。

通常根据水垢的主要成分将它分为碳酸盐水垢；硫酸盐水垢，磷酸盐水垢，硅酸盐水垢和锈垢几、大类。

表3—4是用X—射线法测得的各种坚硬水垢的组成。

表3-4 X—射线反射法测得水垢成分在锅炉受热内部和冷却水热交换系统内部积存水垢都是有害的，其危害性主要表现在以下几方面。

(1)增加热损失和燃料消耗通常工业锅炉每结lmm厚水垢，热效率要降低5％。

中国工业锅炉和采暖锅炉的年燃煤量占煤炭总用量垢，发电锅炉的燃煤量占煤炭总用量毵i以工业锅炉和，采暖锅炉平均结垢厚度方lmm，发电锅炉与腐蚀产物平均厚度为0.5mm计算，则将造成45Mt/a的燃料损失，而如果做好防垢清洗工作每年至少可节约45亿元的燃煤费用。

阿奇霉素二水合物在水-有机溶剂中溶解度及三元相图测定曹小雪;吉绍长;匡雯婕;廖安平;蓝平;张金彦【摘要】The solubility of azithromycinin water + isopropanol and propanone + water solvent mixtures were measured at temperatures from 293.15 K to 323.15 K by an analytical method. The water activity of transformation at 293.15, 298.15, 303.15 and 308.15 K were measured, and the phase diagram of alcoholazithromycin-water at that temperature was obtained through solubility property. The solubility data were correlated by the modified Apelblat equation, λh equation and van't Hoff equation. The results showed that the solubility of azithromycin dihydrate obviously increased with the increase of temperature and the volume fraction of isopropanol and propanone, and the water activity of transformation increased and the coexist area decreased with the increase of temperature. The modified Apelblat equation was the best choice in the correlation of the solubility data.%采用静态法测定了293.15～323.15 K范围内,阿奇霉素二水合物在丙酮-水和异丙醇-水混合溶剂中的溶解度,并研究阿奇霉素在293.15、298.15、303.15及308.15 K温度下丙酮-水混合溶剂中转晶水活度,根据溶解度特性绘制丙酮-阿奇霉素-水三元相图,溶解度数据用Apelblat方程、λh方程和van't Hoff方程进行关联.结果表明,阿奇霉素溶解度随着有机溶剂体积分数和温度的升高而增加,转晶水活度随温度的升高增大,阿奇霉素一水二水共存区域随温度的升高减小,Apelblat方程拟合效果更好,R2≥0.988.【期刊名称】《化工学报》【年(卷),期】2019(070)003【总页数】13页(P817-829)【关键词】阿奇霉素二水合物;溶解度;转晶水活度;Apelblat方程;三元相图【作者】曹小雪;吉绍长;匡雯婕;廖安平;蓝平;张金彦【作者单位】广西民族大学化学化工学院, 广西多糖材料与改性重点实验室, 广西高校化学与生物转化过程新技术重点实验室, 广西南宁 530006;广西烟草专卖局, 广西南宁 530006;广西民族大学化学化工学院, 广西多糖材料与改性重点实验室, 广西高校化学与生物转化过程新技术重点实验室, 广西南宁 530006;广西民族大学化学化工学院, 广西多糖材料与改性重点实验室, 广西高校化学与生物转化过程新技术重点实验室, 广西南宁 530006;广西民族大学化学化工学院, 广西多糖材料与改性重点实验室, 广西高校化学与生物转化过程新技术重点实验室, 广西南宁530006;广西民族大学化学化工学院, 广西多糖材料与改性重点实验室, 广西高校化学与生物转化过程新技术重点实验室, 广西南宁 530006【正文语种】中文【中图分类】TQ026.5引言阿奇霉素(9-脱氧-9a-甲基-9a-氮杂-9a-高红霉素A，C38H72N2O12，结构式见图1)，是第一个氮杂内酯类抗生素[1]，衍生自红霉素，是一种在红霉素结构上进行修饰和改造得到的广谱抗生素[2]，其抗菌作用机理同红霉素相仿，都是通过抑制、干扰细菌蛋白质合成发挥作用，与红霉素相比阿奇霉素在剂量和疗效方面都有明显的优势[3-4]，阿奇霉素在酸性环境中稳定，克服了红霉素在酸性环境极易失活的缺点，在体内热力学性质、动力学性质更加稳定，生物利用度高，肠道吸收好，作用更加持久，极大改善了抗菌活性，被广泛应用于治疗呼吸系统、泌尿系统及软组织感染等疾病[5]。

带你全⾯认识结晶技术，这⼀次真是⼤开眼界结晶分离法是⼀个古⽼⽽⼜现代的分离技术，⽤该技术可以制得纳⽶级的化⼯产品，也可以制得直径达⼏英吋的晶柱。

该技术在化⼯⽣产及⼈们的⽇常⽣产中仍发挥着巨⼤的作⽤。

晶体与结晶结晶是分⼦、原⼦或离⼦的有规则地排列⽅式具有⼀定的熔化温度(熔点)和固定的⼏何形状，在物理性质⽅⾯⼜往往具有各向异性的现象。

晶体是有明确衍射图案的固体，其原⼦或分⼦在空间按⼀定规律周期重复地排列。

晶体中原⼦或分⼦的排列具有三维空间的周期性，隔⼀定的距离重复出现，这种周期性规律是晶体结构中最基本的特征。

晶体可分为三⼤晶族，七⼤晶系如下：⾼级晶族：等轴晶系中级晶族：三⽅晶系、四⽅晶系、六⽅晶系低级晶族：斜⽅晶系、单斜晶系、三斜晶系。

结晶的基本原理将⼀个被溶解物放⼊⼀个溶剂中，由于分⼦的热运动，必然发⽣两个过程：(1)固体的溶解，即被溶解物质(溶质)分⼦扩散进⼊液体内部。

(2)物质的沉积，即溶质分⼦由液体中扩散到固体表⾯进⾏沉积，⼀定时间后，这两种分⼦扩散过程达到动态平衡。

我们将能够与固相处于平衡的溶液称为该固体的饱和溶液。

图中两条曲线将温度—浓度图分成三个区域：(1)稳定区：其浓度等于或低于平衡浓度，在这⾥不可能发⽣结晶。

(2)介稳区：⼜可细分为两个区：第⼀个分区称为亚稳区，位于平衡浓度与低于它就基本上不可能发⽣均相成核的浓度之间；第⼆个分区称为过渡区，与这个区相对应的浓度则是有能⾃发成核的浓度，但不马上发⽣，⽽是要经过某⼀时间间隔才发⽣，总的来说，在介稳区，结晶不能⾃动进⾏，但如加⼊晶体，则能诱导结晶进⾏。

这时，主要是⼆次成核。

这种加⼊的晶体称为晶种。

(3)不稳定区：溶液处于不稳定态，特点是结晶马上开始，均相成核，出现连⽣体和树枝状的结晶。

与这⼀状态相应的浓度是超过过饱和曲线的浓度。

理论：在⼀定的条件下，沉淀（结晶）能否⽣成或⽣成的沉淀是否溶解，取决于该沉淀的溶度积。

当沉淀剂加⼊溶液中时，mAn++nBm-=AmBn（固）↓，形成的离⼦浓度的乘积Q=[An+]m[Bm-]n⼤于沉淀物的溶度积（Ksp），即Q＞Ksp时，形成了过饱和溶液，离⼦通过互相碰撞形成微⼩的晶核——成核过程；晶核形成后溶液中的构晶离⼦向晶核表⾯扩散，并沉积在晶核上——晶核⽣长；晶核就逐渐长⼤成晶粒；晶粒进⼀步聚集、定向排列成晶体，如果来不及定向排列则成为⾮晶粒沉淀。

Vol.53 No.6June,2021第 53 卷 第 6 期2021 年 6 月无机盐工业INORGANIC CHEMICALS INDUSTRYaDoi:10.19964/j.issn.1006-4990.2020-0368开放科学（资源服务）标志识码（OSID ）工业级磷酸二氢铵生产工艺研究进展王智娟\韦昌桃2(1.曲靖师范学院化学与环境科学学院，云南曲靖655000；2.云南云天化股份有限公司)摘 要:磷酸二氢铵是典型的精细磷酸盐产品，在农业、消防、食品和材料等领域有广阔的应用及市场前景，需 求量不断增大，工业级以上磷酸二氢铵的生产技术研究越来越引起人们的重视。

制备工业级磷酸二氢铵的技术路线主要有热法磷酸路线、净化湿法磷酸路线。

热法磷酸生产路线耗能高、污染大、成本高,该生产技术路线逐渐受限;溶剂萃取法净化湿法磷酸生产工业级磷酸二氢铵路线，产品纯度高、质量好、自动化程度高，但是流程复杂、投资大、成 本高。

因此近年来探索其他途径制备工业级磷酸二氢铵的研究不断增多。

综述了以热法磷酸、净化湿法磷酸、湿法磷酸、萃余酸和磷酸脲母液为原料制备工业级磷酸二氢铵的技术路线,并且评述了各工艺的特点。

就目前而言，由廉价易得的湿法磷酸直接制备高附加值的工业级磷酸二氢铵是研究的重点，提高产品纯度和五氧化二磷收率、改善料浆的过滤性能、探索氨化除杂后滤渣的再利用途径是该方法急需解决的问题。

关键词:工业级磷酸二氢铵;制备工艺;湿法磷酸中图分类号:TQ126.35 文献标识码:A 文章编号：1006-4990(2021)06-0118-05Research progress on production process of industrial grade ammonium dihydrogen phosphateWang Zhijuan 1, Wei Changtao 2（1.Faculty of Chemistry and Environment Science , Qujing Normal University ,Qujing 655000, China ； 2.Yunnan Yuntianhua Co. ,Ltd. 冤Abstract : Ammonium dihydrogen phosphate is a typical fine phosphate product,which has a wide range of applications and excellent market prospects in agriculture,fire protection,food,materials and many other fields.With the ever-increasingdemand for ammonium dihydrogen phosphate,research on the producing process of industrial grade ammonium dihydrogen phosphate has attracted more and more attention.The main technical routes for the preparation of industrial grade ammoniumdihydrogen phosphate include hot-process phosphoric acid route and wet-process purified phosphoric acid route,the hot-pro ­cess phosphoric acid route shows high energy consumption,high pollution and high cost,which is gradually restricted,while the route of purifying wet-process phosphoric acid route by solvent extraction to produce industrial grade ammonium dihydro ­gen phosphate has high purity,good quality and high degree of automation,but the process is complex,large investment andhigh cost.Therefore,in recent years,more and more research has been carried out to explore other ways to prepare industrial grade ammonium dihydrogen phosphate.Herein,the technical routes of preparing industrial grade ammonium dihydrogenphosphate from thermal process phosphoric acid,purified wet-process phosphoric acid,wet-process phosphoric acid,raffinateacid and urea phosphate mother liquid were reviewed.The characteristics of each process were discussed in detail.At present, producing high value-added high purity ammonium dihydrogen phosphate from wet-process phosphoric acid is the focus of research which is cheap and easy to obtain.It is urgent for this method to increase the purity of product and P 2O 5 yield , toimprove the filtration performance of the slurry and to explore the appropriate reuse methods of filter residues after removingimpurities with ammoniation.Key words : industrial grade ammonium dihydrogen phosphate ； preparing process ； wet-process phosphoric acid工业级以上的磷酸二氢铵(MAP )用途广泛，是 高纯度的氮磷二元复合肥料，也是制备氮磷钾三元 复合肥、水溶肥、滴灌肥和喷施肥的重要原料,可显著提高肥料的利用率,降低水资源消耗[1],在节水节肥、水肥一体化方面发挥着重要作用。

磷酸氢钙制备磷酸二氢钾的工艺研究Ⅱ——母液的净化、蒸发和结晶李春丽;关云山;张志强;邢英;梁之帅;张英智;何全胜【摘要】以明胶厂富产的磷酸氢钙为原料,与硫酸钾在液相中进行复分解反应,得到的母液经净化、蒸发和结晶制备得到磷酸二氢钾.考察了母液净化方式、母液pH、水蒸发量和自然冷却结晶等过程对产品纯度和质量的影响.结果表明:以氢氧化钠作除杂剂,控制母液pH =4.5,水蒸发量为70％(质量分数),自然冷却结晶得到的磷酸二氢钾产品可以达到国家工业一等品标准.%After purification, evaporation, and crystallization, potassium dihydrogen phosphate was manufactured with mother liquid,which was prepared with calcium phosphate by-produced from gelatin plant and potassium sulfate by double decomposition reaction. Influences of the way of purification, pH of mother liquid, evaporation process, and natural cooling crystallization process on the purity and quality of product were also studied. Results showed that when sodium hydroxide was used as trash-removal agent,pH of mother liquid was 4.5,water evaporation was at 70% (mass fraction) ,and natural cooling crystallization was adopted, the quality of potassium dihydrogen phosphate reached the first grade requirement of the national industrial standard.【期刊名称】《无机盐工业》【年(卷),期】2011(043)008【总页数】3页(P51-53)【关键词】磷酸二氢钾;母液;磷酸氢钙;明胶【作者】李春丽;关云山;张志强;邢英;梁之帅;张英智;何全胜【作者单位】青海大学化工学院,青海西宁810016;青海大学化工学院,青海西宁810016;青海大学化工学院,青海西宁810016;青海大学化工学院,青海西宁810016;青海大学化工学院,青海西宁810016;青海大学化工学院,青海西宁810016;青海明胶股份有限公司【正文语种】中文【中图分类】TQ126.35明胶生产中富产大量的磷酸氢钙,主要作为动物饲料添加剂使用，由于该产品技术含量低，因此价格受市场影响大。

AbstractAll that including both sodium phosphite and sodium hypophosphite, as new products of phosphates, are widely applied for chemical industries and materials as various reductors. What the reason exists is that the reducibility of phosphite is weaker and more stable than sodium hypophosphite, to some extent, it is with better stability and safety when replacing sodium hypophosphite as redactor. Research on the production of sodium hypophosphite is seldom carried out in the domestic and overseas now, which is mainly recovered from sodium hypophosphite in industrial waste in the method of metathesis reaction, but products recovered is with low yield, poor quality, complicated operation and no environmental protection. The sodium hydroxide and sodium carbonate, as raw materials, respectively make a neutralization reaction with phosphorous acid to become sodium phosphite in order to obtain high quality sodium phosphite with production process, crystallization thermodynamics and crystallization kinetics studied to acquire the optimized production process and crystallization kinetics equation of disodium hydrogen phosphate, which provides theoretical guidance for industrial production in this paper.There were two transitions in the neutralization titration process between phosphorous acid and sodium hydroxide or sodium carbonate by the potentiometric titration, and the reaction product was mainly in the form of disodium hydrogen phosphite at pH 6 to 8. Effect on the neutralization reaction temperature and time, phosphorous acid concentration and molar ratio to reaction product by single factor test was discussed to obtain the optimum conditions below：(1) phosphorous acid was neutralized with sodium hydroxide to disodium hydrogen phosphite, with 1: 2 as molar ratio (H3PO3: NaOH), concentration of phosphorous acid of below 8.54 mol / L, and no effect on reaction temperature and reaction time to reaction product.(2) sodium carbonate was reacted with phosphoric acid to disodium hydrogen phosphite, with 1: 1 as the molar ratio（H3PO3 : Na2CO3）and no effect on reaction temperature , reaction time and phosphorous acid concentration to reaction product. The products prepared under the optimized conditions were characterized by XRD, and the product was identified as disodium hydrogen phosphite.The crystallization thermodynamics of disodium hydrogen phosphate was investigated by static method to determine the solubility and super solubility in the aqueous solution in temperature of 25 °C to 80 °C. The results showed that the℃℃solubility and super solubility of disodium hydrogenphosphite at 25 to 80 was increasing with the increase of temperature. It was consistent with the classical nucleation theory that the simplified empirical equation of Apelblat was obtained by fitting to obtain the distribution of metastable zone of disodium hydrogen phosphite at 20 to 80 found the metastable zone becoming narrower with the increase of℃℃temperature as well as the stirring rate and the metastable zone becoming widened with the increase of the cooling rate. Crystallization thermodynamics analysis showed that the crystallization operation of bisulfite was carried out under the conditions of℃stirring rate of 200 rpm and cooling rate of 15 / h.The crystallization kinetics of disodium hydrogen phosphite was studied by intermittent dynamic method to prove that phosphorous acid and sodium hydroxide were easy to form uniform and small disodium hydrogen phosphite whose crystal growth was not relevant to particle size at the particle size of above 15 μm. The volume fraction of particle size of the product was measured to gain the nucleation rate of corresponding time interval by laser particle size analyzer based on relationship between grain number balance and mass balance by moment transformation method to be crystal growth rate equation of the reaction with retrogression. a small amount of coarse seeds were added at the position of the central partial in the metastable zone bias over super solubility curve could acquire larger crystal of sodium hydrogen phosphite crystals with the evaporation temperature of ℃roughly 150 and 200 rpm stirring speed crystallization, which was consistent with the conclusion of crystallization thermodynamics.Keywords: disodium hydrogen phosphite; neutral method; crystallization thermodynamics; crystallization kinetic目录摘要 (I)Abstract ..................................................................................................... I II 目录.. (V)第1章文献综述 (1)1.1 磷酸盐的背景及应用 (1)1.2 次磷酸盐的背景及应用 (2)1.3 亚磷酸盐的背景及应用 (3)1.4 亚磷酸钠制备工艺 (4)1.4.1 中和法 (4)1.4.2 复分解法 (4)1.5 蒸发结晶 (5)1.6 课题研究的内容及意义 (6)第2章亚磷酸钠制备工艺研究 (7)2.1 实验材料与仪器 (7)2.1.1 实验材料 (7)2.1.2 实验仪器 (7)2.2实验项目与方法 (8)2.2.1电位滴定分析 (8)2.2.2亚磷酸与氢氧化钠中和反应 (8)2.2.3亚磷酸与碳酸钠中和反应 (9)2.3 实验结果与讨论 (9)2.3.1 电位滴定分析 (9)2.3.2 温度对中和反应产物的影响 (11)2.3.3 反应时间对中和反应产物的影响 (13)2.3.4 亚磷酸浓度对中和反应产物的影响 (14)2.3.5 不同摩尔比对反应产物的影响 (15)2.3.6 优化条件下反应产物的XRD表征 (17)本章小结 (17)第3章亚磷酸钠结晶热力学研究 (19)3.1.1 溶解度简介 (19)3.1.2 溶解度的测定方法 (19)3.1.3 固液平衡 (20)3.1.4 介稳区 (22)3.2 实验材料与仪器 (23)3.2.1 实验材料 (23)3.2.2 实验仪器 (24)3.3 试验项目和方法 (25)3.3.1 亚磷酸钠在水中的溶解度测定 (25)3.3.2 亚磷酸钠在水中的超溶解度测定 (25)3.4 实验结果与讨论 (26)3.4.1 亚磷酸氢二钠在水中的溶解度 (26)3.4.2 亚磷酸钠在水中的介稳区 (27)本章小结 (29)第4章亚磷酸钠结晶动力学研究 (31)4.1 结晶动力学理论 (31)4.1.1 晶核的形成 (31)4.1.2 二次成核 (32)4.1.3 晶体的生长 (33)4.1.4 晶体生长动力学模型 (34)4.2 结晶动力学的测试方法 (35)4.2.1 连续稳态法 (36)4.2.2 连续动态法 (36)4.2.3 间歇动态法 (37)4.3 实验材料与仪器 (39)4.3.1 实验材料 (39)4.3.2 实验仪器 (39)4.4 实验项目和方法 (39)4.4.1 亚磷酸钠结晶动力学 (39)4.4.2 影响亚磷酸钠结晶过程的因素 (40)4.5.1 亚磷酸氢二钠粒度相关性 (41)4.5.2 亚磷酸钠结晶动力学方程 (41)4.5.3 晶种对晶体粒径的影响 (42)4.5.4 晶种加入时机对产品粒径的影响 (42)4.5.5 搅拌速度对晶体粒径的影响 (43)4.5.6 蒸发温度对晶体粒径的影响 (44)本章小结 (45)第5章结论 (47)主要符号说明 (49)参考文献 (53)攻读硕士期间发表的论文 (59)致谢 (61)第1章文献综述1.1磷酸盐的背景及应用磷作为一种化工原料性产品，其用途非常广泛，在我国的经济中占据十分重要的地位[1]。