氨-硫酸铵法生产饲料级氧化锌中除砷工艺研究

以锌焙砂和氨-硫酸铵溶液为原料生产饲料级高纯氧化锌,对除砷进行了重点研究.采用沉淀混凝吸附法,先用氧化剂氧化砷(Ⅲ)成砷(Ⅴ),再用沉淀吸附剂沉淀砷(Ⅴ).结果表明,温度为60℃,砷与氧化剂及沉淀吸附剂的物质的量比为1,0:1.2:1.2,搅拌浸出2 h,静置1 h,除砷效果最好.通过除砷所得氧化锌产品各项指标都符合HG 2792-1996标准.革新了氨法生产氧化锌的除砷工艺.     

从烟道灰制备饲料级氧化锌

研究了以含氯烟道灰为原料,经酸浸、除杂、合成制得中间产物碱式碳酸锌,碱式碳酸锌经过滤、洗涤、干燥、煅烧制备饲料级氧化锌的新工艺.重点考察了制备工艺中酸浸、除杂条件以及煅烧温度和时间对产品质量的影响.结果表明:采用质量分数为30%的硫酸浸取,可使锌浸出率达到95%;采用质量分数为27.5%的过氧化氢溶液氧化除铁和锌粉两段置换可彻底除杂;控制煅烧温度800℃,煅烧时间4 h,可制备氧化锌质量分数达到98%的饲料级氧化锌产品.该方法利用了廉价的烟道灰,具有原料来源广泛、生产成本低的优势,制备的产品质量可达到HG/T 2792-1996饲料级氧化锌一等品标准.     

Influence of ammonia concentration on anodic deposition of nickel oxide

Nickel oxide was prepared by anodic deposition in a basic solution comprising nickel chloride, ammonium chloride and ammonia. The influence of ammonia was investigated using galvanostatic reduction techniques and cyclic voltammetry (CV). It was found that the oxidization peak potentials shift positively with decreasing ammonia concentration, while the oxidization peak currents firstly increase with decreasing ammonia concentration and then decrease when the ammonia concentration is lower than 1.67 mol L⁻¹. This is mainly attributed to the fact that the equilibrium concentration of Ni(OH)_2(aq) varies with the ammonia concentration. A potential plateau at about 0.75 V was observed in galvanostatic reduction curves for nickel oxide, and the length of the potential plateau in solution with 1.67 mol L⁻¹ ammonia concentration was longer than that in the other solutions, which agreed well with the CV results.     

氨配合氧化法由氧化锌烟灰制备活性氧化锌

本研究以氧化锌烟灰或粗氧化锌为原料，用氨水—碳酸氢铵—双氧水作浸取液。将氧化锌烟灰或粗氧化锌浸取、除杂净化、蒸氨沉锌、洗涤干燥、煅烧即可制得高品位的活性氧化锌。     

蒸氨法氨回收工艺及装置简介

农药厂IDAN法草甘磷在碱解反应中产生大量的含氨气体,采用中压蒸氨工艺回收氨。介绍了低压解吸蒸氨工艺和中压蒸氨工艺各自的特点,阐述了中压蒸氨工艺流程、产品质量、消耗指标、工艺指标、主要设备,介绍了生产成本、收益情况,并进行了分析。     

饲料磷酸氢钙生产技术进展

分析了近年来中国两段中和法生产饲料磷酸氢钙工艺路线的进展及存在的问题。虽然改进的工艺带来了饲肥比的提高，但其脱氟渣（粗肥）的存在，使饲料磷酸氢钙产品的总磷收率仍然偏低。为了进一步提高五氧化二磷收率，探讨了磷酸预分解磷矿，再中和脱氟的新工艺，该工艺不仅流程短，不产生粗肥，生产环境好，而且节省20％-30％的硫酸，少用了近50％的石灰，五氧化二磷收率明显提高，给饲料磷酸氢钙生产带来较好的经济效益。     

高温水解和水蒸气蒸馏样品处理法在氧化锌中氟和氯含量测定的比较

氧化锌中氟和氯的主要形态有NaCl,KCl,Zn₅(OH)₈Cl₂·H₂O、Pb(OH)Cl和PbClF。分别采用高温水解法和水蒸气蒸馏法提取了不同氟、氯存在形态的氧化锌样品,采用离子色谱法测定氟和氯含量,对两种提取方法的测定结果进行比较。实验结果表明两种方法的测定值一致,高温水解法较水蒸气蒸馏法处理样品检测结果精密度更高,操作简便,硫酸根离子残留少,离子色谱洗脱耗时短。     

利用次氧化锌粉制备活性氧化锌工艺研究

研究了利用硫酸浸出次氧化锌粉制备活性氧化锌的工艺。讨论了浸出过程中液固比、硫酸浓度对浸出率的影响;采用加氧化锌粉末、加热、调节pH和锌粉置换的方法提纯硫酸锌溶液;采用碳酸氢铵作为沉淀剂制备前驱体碱式碳酸锌。通过实验,确定了利用次氧化锌粉制备活性氧化锌的工艺参数。采用扫描电镜和X射线衍射对活性氧化锌进行了表征,结果表明：活性氧化锌的粒度分布均匀,形貌为球形立方,产品纯度高,氧化锌质量分数为99.48%。     

饲料级脱氟磷酸三钙生产工艺研究

本文简要介绍了饲料级脱氟磷酸三钙的发展前景、国内外生产现状、生产原理以及生产原料磷矿的分布情况和特点,重点综述了国内外饲料级脱氟磷酸三钙生产工艺的优缺点及开发应用现状,并对我国脱氟磷酸三钙工业的发展提出了建议。     

In-situ study of electrophoretic deposition of zinc oxide nanosheets and nanorods

In the present work, the effects of two different morphologies of zinc oxide nanoparticles (nanosheets and nanorods) were investigated by in-situ measurement of deposition weight, and current density. ZnO nanosheets and nanorods were synthesized by microwave-assisted method using co-surfactant route. The average thickness of obtained nanosheets, and the average diameter of nanorods were measured to be about 26 nm and 139 nm, respectively. ZnO films were obtained by electrophoretic deposition from suspension of nanoparticles in ethanol under different voltages. Results indicated that ZnO nanosheets tend to have greater deposition rate than ZnO nanorods under similar conditions. The compactness of the film obtained from nanosheet suspension was higher than the one obtained from nanorod suspension. However, the film obtained from ZnO nanorods displayed more uniformity at different voltages in comparison to the film obtained from ZnO nanosheets, which can be due to different active surface area, and also different way of motion under hydrodynamic forces in the suspension.     

反应精馏过程模拟研究进展

对均相反应精馏和非均相催化精馏过程的各种模拟计算方法进行了评述，分析了各种算法的优缺点和适用范围，指明了目前研究中存在的不足和今后的发展方向。