原位一步合成CuAl-LDHs-聚磷酸铵及其在聚丙烯阻燃中的应用

采用原位一步法合成铜铝类水滑石（CuAl-LDHs）,通过控制铝酸钠/聚磷酸铵（NaAlO₂/APP）的质量比（0.82~3.28）合成CuAl-LDHs-APP。采用XRD、FTIR、SEM和TG对所制备的CuAl-LDHs及CuAl-LDHs-APP进行表征。采用极限氧指数（LOI）、垂直燃烧（UL-94）测试、弯曲及拉伸试验等考察了CuAl-LDHs/聚丙烯（PP）及CuAl-LDHs-APP/PP复合材料的阻燃性能及力学性能。SEM 观察表明:LDHs结构为片状,随着NaAlO₂与APP质量比的减小,CuAl-LDHs-APP颗粒粒径相应减小,当NaAlO₂与APP的质量比为0.82时,CuAl-LDHs-APP颗粒粒径达到20 nm左右,比表面积为183.5 m2/g。TG分析表明:CuAl-LDHs-APP在高温下有较好的热稳定性。当PP中加入质量分数为20%的CuAl-LDHs及CuAl-LDHs-APP时,LDHs/PP复合材料表面形成炭层;当NaAlO₂与APP质量比不大于1.64时,CuAl-LDHs-APP的添加可抑制PP燃烧时产生的熔滴现象;与CuAl-LDHs/PP复合材料相比,CuAl-LDHs-APP/PP复合材料具有更好的阻燃性能和力学性能;与PP材料相比,CuAl-LDHs-APP/PP复合材料的弯曲强度和拉伸强度等力学性能的下降也不明显。      

水热法合成一维纳米级MoO_3微粉

以仲钼酸铵为钼源,选用强弱不同的酸使仲钼酸铵酸化水解生成中间体,经洗涤、干燥、焙烧,制备了淡灰蓝色纳米级MoO3微粉;研究了溶液酸度、钼酸铵浓度、焙烧温度等因素对MoO3微粉相对结晶度、晶体尺寸和形貌的影响。     

双极膜电渗析制备偏钨酸铵溶液的初步研究

提出了一种双极膜电渗析制备偏钨酸铵的新工艺并对该工艺进行了初步的试验研究。结果表明,双极膜电渗析能有效将钨酸铵溶液转化为偏钨酸铵溶液,过程运行稳定,电流效率达73.84%,每吨WO3直流电耗仅为864.3 kW·h,WO3直收率大于99.5%。新工艺直接采用工业钨酸铵溶液为原料,具有原料成本低、收率高,产品质量好和环境友好等特点。     

山东焦家金矿爆破工艺优化研究

随着焦家金矿开采深度的不断下移,岩石硬度系数逐渐变大,普通乳化油炸药配合角柱式掏槽或五角梅花空心掏槽技术爆破效率低,已无法满足高效生产形势的要求。本文通过引进“粒状乳化铵油炸药”及其大直径中心空眼螺旋掏槽技术,提高了单循环作业进尺。同时,由于其爆破技术产生的有毒和有害气体相对减少,缩短了通风时间,加快了作业循环,提高了工效。这项技术大大提升了掘进工作面的进尺,加快了开拓工程进度。     

钼精矿焙烧烟道灰中铼的回收

含铼钼精矿经外加热式回转窑焙烧,伴生的稀贵金属铼进入烟尘,采用自激式高效收尘方式和装置进行回收,对焙烧烟尘中的主要成分进行分析,研究了浸出过程的主要影响因素:浸出剂、酸度、温度、时间、液固比等,把回收的含铼钼粉尘进行溶解,通过添加氧化剂,提高铼的浸出率,将含铼溶液,选择强碱性阴离子交换树脂201×7吸附,再用萃取剂萃取,用7N的氨水反萃,铼进入反萃液中,再用氨水解吸、蒸发、结晶得高铼酸铵。该工艺有效的回收了烟尘中的铼,粉尘回收率可达到98%以上,减少粉尘排放,降低环境污染;烟尘中的铼的浸出率在98%以上;溶液中铼的吸附率在99%以上,附铼树脂上铼的解析率在99%以上;铼酸铵纯度≥99.99%,总回收率≥98%;提高了矿产资源综合利用率及经济效益,为企业增加了新的经济增长点。     

十二钼酸铵焙解工艺研究

通过研究焙解十二钼酸铵制备高纯三氧化钼工艺,探讨钼酸铵焙解工艺各个影响因素之间的关系;在不同条件下制备出形貌各异、粒度不同的高纯三氧化钼,阐述了钼酸铵焙解条件与高纯三氧化钼特征影射关系。     

钼酸铵生产的湿法冶炼工艺

钼酸铵是冶金化工生产的一种重要的深加工原料。以钼焙砂为原料生产钼酸铵的湿法冶炼工艺比较多,目前应用比较广泛的主要有2种,既经典氨浸法和离子交换法。本文对2种工艺作了利弊分析,研究认为离子交换法所排放的生产污水氨氮含量低,基于环境保护国策,我国今后钼酸铵生产项目的改扩建或新建工程宜采用离子交换工艺。     

影响酸性铵盐沉淀因素的研究

以钒渣氧化钠化焙烧—水浸后的钒液为原料,进行间断式酸性铵盐沉钒试验。讨论了沉淀原液浓度、pH值、温度、氯化铵加入量、沉钒时间、钒液杂质(P/Si)等对钒酸铵质量的影响。试验结果证明,采用酸性铵盐沉钒的最佳工艺条件:沉淀原液浓度20～21 g/L、pH值8～9、磷含量<15 mg/L、硅含量<500 mg/L、沉钒初始温度控制在40～50℃,最终温度控制在95～100℃、加铵系数0.5～0.6、沉淀沸腾时间20～30 min,可制得品位高、杂质含量低的钒酸铵。     

Evaluation of 0.1% Ammonium Hydroxide to Replace Sodium Tripolyphosphate in Fresh Meat Injection Brines

ABSTRACT:  Paired USDA Select beef strip loins ( n  = 10), aged 2 d, were injected with either an alkaline-based (3.6% sodium chloride, 1% Herbalox seasoning, adjusted to pH 10 with ammonium hydroxide [approximately 0.1%, FFC grade]) or a phosphate-based (3.6% sodium chloride, 1% Herbalox seasoning, 4.5% sodium tripolyphosphate) brine. Steaks were evaluated for 19 d. Overall, phosphate-injected steaks performed better than alkaline-injected steaks with respect to cook yield, water holding capacity, lipid oxidation, color stability, tenderness, and juiciness. Phosphate-injected steaks also had less purge than alkaline-injected steaks, as confirmed by composition analysis. Phosphate-injected steaks were higher in moisture and ash content, and were nearly 2% lower in protein content. Alkaline-injected steaks had significantly lower aerobic (approximately 1 log lower) and anaerobic (approximately 2 log lower) plate counts. Final meat pH probably contributed to the differences observed between treatments. The final pH of phosphate-injected steak was 5.99 while that of alkaline-injected steak was 5.73. Further research should be conducted to determine the concentration of ammonium hydroxide needed in the alkaline-based brine to increase the final meat pH to similar levels found in the phosphate-injected steaks.     

Kinetics of Dissolution of Tenorite in Ammonium Media

In this work, the dissolution kinetics of tenorite (CuO) in a NH₄OH-H₂O system was studied. The studied temperature range was 5–55°C, ammonium hydroxide concentration between 0.1 and 0.75 M, and a particle size range of 5–24 µm. The stirring speed, pH of the ammonia solution, and various agents were also studied. The results indicated that the leaching of tenorite occurred quickly with a particle size of 5 µm in a 0.45 M solution of NH₄OH for a pH value equal to 10.5. Dissolution of CuO also increases as temperature and the concentration of NH₄OH increase. For concentrations less than 0.10 M, there is almost no leaching tenorite. By decreasing the particle size, the dissolution of CuO increase. Results show the stirring speed had no significant effect on the leaching rate of tenorite for values above 250 rpm. Leaching kinetics was analyzed using the model of the surface chemical reaction. The reaction rate was of the order of 2.2 with respect to the concentration of ammonium hydroxide and inversely proportional to the initial particle size. Activation energy of 59 kJ/mol was estimated for the temperature range of 5–55°C.