超声波辅助硫化镍矿氧化浸出动力学

选用过硫酸盐+银盐作氧化剂,在超声波作用下对硫化镍矿进行直接氧化浸出,研究搅拌速率、过硫酸钠浓度、浸出温度、银盐浓度及粒度对镍浸出率的影响规律,探讨氧化浸出反应机理。结果表明:在一定范围内,在超声波作用下搅拌速率或者粒度的变化对镍浸出率影响不显著;镍浸出率随Na2S2O8浓度的增大以及温度的升高而增加,但是当温度高于70℃后,浸出率的增加不明显;在浸出过程中起主导作用的是S2O82-,少量银盐的存在对浸出反应有促进作用。通过对该体系浸出过程动力学参数的考察,发现其符合缩核模型,过程总体反应速率受界面化学反应控制,表观活化能为39.67kJ/mol,建立了浸出过程的宏观动力学方程。     

聚乙烯生产技术中催化剂研究进展

阐述了目前世界聚乙烯催化剂的新发展,包括Z-N催化剂、茂金属、单中心催化剂、非茂金属催化剂技术进展,聚乙烯生产工艺的催化剂改进,使得催化效率呈现几何级数的提高,从而简化了聚烯烃生产工艺,降低了能耗和物耗,进一步推动我国聚乙烯产品的结构和性能调整。     

低变质粉煤成型热解的研究

以陕北低变质粉煤为原料,采用冷压成型制备型煤,主要研究焦煤添加量、添加水分、成型压力、热解温度的影响。结果表明:以焦煤作粘结剂进行型煤热解实验的研究中,可发现型煤(型焦)的抗压强度均随着焦煤加入量的增大而升高,选用10%的焦煤较为适宜;在一定范围内,型煤的强度随着成型压力的增大而增大,选择60kN的强度较为适宜;型煤的强度随着成型压力的增大而增大,14%的水分更佳;型焦的强度在700℃以上就趋于平稳化,故选择的热解温度为700℃。     

交联壳聚糖吸附树脂的制备

文章用甲醛交联壳聚糖制备了一种新型的吸附树脂,探讨了几种反应因素对交联率的影响,并进行了树脂的表征。结果表明,甲醛交联壳聚糖的反应主要发生在壳聚糖分子的氨基和羟基上;当壳聚糖与甲醛的质量比为1∶5,体系反应温度为60℃,反应时间为1 h,搅拌速率为440 r/min,pH为10时,可制得成球性好,耐酸性强的壳聚糖基树脂吸附材料。     

聚丙烯无纺布预辐射法固相接枝甲基丙烯酸甲酯的研究

研究了以预辐射聚丙烯无纺布为基材,甲基丙烯酸甲酯为单体,采用固相接枝聚合的方法制备接枝共聚物的接枝反应过程。详细讨论了反应温度、反应时间、阻聚剂、单体浓度和交联剂等对接枝率的影响。结果表明,该接枝反应的最佳条件为:温度65℃、时间2 h、单体浓度20%、交联剂5%、阻聚剂(FeSO4.7H2O)0.3 g,在此条件下的接枝率为6.64%。     

硫化镍精矿超声波辅助氧化浸出特性(英文)

The feasibility of oxidation leaching process of nickel from nickel sulfide ore and the form of different components in the lixivium has been studied at first. The method of leaching nickel sulfide concentration directly by oxidants with existence of ultrasonic has been advanced. The process of leaching nickel from nickel sulfide concentration by using the system of persulfate and silver has been determined. The influence of different factors on the leaching rates of nickel, such as with and without ultrasonic, the concentration of Na2S2O8, liquid-solid ratio and the concentration of AgNO3 have been explored. The results show that: (1) in the oxidative leaching system, nickel can be leached completely as Ni2+ or NiSO4(aq.)from nickel sulfide concentration in theory; (2) the nicopyrite can not exist steadily in the persulfate acid leaching system, but Ni2+can. Meanwhile, sulfur may be existed steadily in the leaching process; (3) nicopyrite with much lower electrostatic potential may be leached earlier than chalcopyrite and sideropyrite; and (4) the overall reaction rate of the leaching process can be enhanced with ultrasonic radiation, but it does not change the mecha-nism of leaching. The more oxidant concentration or higher liquid-solid ratio is, the higher leaching percentage of nickel. The leach-ing percentage of nickel can be increased significantly by adding a small amount of AgNO3 during the leaching processes. Under the same conditions, the higher concentration of AgNO3 is, the higher leaching yields of nickel will be obtained.     

环氧氯丙烷交联壳聚糖树脂的制备研究

采用环氧氯丙烷交联壳聚糖制备了一种新型的吸附树脂材料,探讨了反应物配比,反应温度,反应时间,搅拌速率以及体系pH值等因素对交联率的影响,并通过红外光谱进行了树脂的表征。研究结果表明,环氧氯丙烷交联壳聚糖的反应主要发生在壳聚糖分子的氨基和羟基上;当体系反应温度为50℃,反应时间为9 h,搅拌速率为400 r／min, pH值为12,壳聚糖与环氧氯丙烷的质量比为1：6时,可制得耐酸性强、并且交联度高的壳聚糖基树脂吸附材料。