共查询到20条相似文献,搜索用时 843 毫秒
1.
我厂碳铵改产尿素工程自1986年底投产以来,经过一年的运行,经测定各项技术指标均达到设计水平。1987年共产尿素33403吨,合格率90%,但是一级品率很低,只有8.3%。进入1988年后,我们把提高尿素产品一级品率作为车间和班组管理的重要目标之一。针对出现的问题,认真分析原因,对设备、工艺进行了改造,使一级品率不断提高。1988年1~5月份共生产尿素18487.35吨,合格品率99.9%,一级品率37.8%,4月份一级品率已达到61.5%。我们采取的措施及过程如下; 1.缩二脲是尿素生产过程中的副产物,贯串在生产的全过程。其反应速度和生成量与氨的分压、尿液的温度及在系统设备管道中的停留时间有关。在尿素塔内,虽然反应温度高,停留时间 相似文献
2.
从低品位铅锌矿制备氧化锌和红丹 总被引:2,自引:0,他引:2
研究了从低品位铅锌矿直接制备出高质量的氧化锌和红丹的工艺条件,从氯化锌溶液中净化除去杂质的方法,制成氧化锌和红丹的技术条件等。结果表明,氧化锌和红丹的质量都超过了国家标准一级品,还可以综合回收矿物中的其它有价元素。 相似文献
3.
4.
5.
将活性氧化锌等量或减量替代间接法氧化锌应用于轻载轮胎胎面胶中(配方含胶率不变),可使胶料物理机械性能接近或稍高于应用间接法氧化锌的胶料,并使胶料成本有所下降。 相似文献
6.
采用有机锌替代氧化锌在硫黄硫化体系、高促低硫有效硫化体系和过氧化物硫化体系以及不同用量的有机锌进行实验。结果表明,在不同硫化体系中均可替代氧化锌,用量5份可达到氧化锌6 份的效果,性能不变。在生产配方中使用,胶料性能和产品质量符合标准,有较好的经济效益和环境效益。 相似文献
7.
本文依据全面质量管理原理,应用简便的数理统计方法(二表二图),细致地查明搪瓷高脚痰盂在生产过程中存在的各种提出改进质量的具体措施,达到显著提高一级品率和合格率。 相似文献
8.
介绍了使用全木浆生产粘胶长丝的工艺控制,以及使用全木浆出现的问题和解决措施。使用全木浆生产粘胶长丝,木浆所制得的粘胶质量比棉浆差,纺丝可纺性较差,粘胶长丝的质量指标能达到等级品水平,但一级品率很低。 相似文献
9.
介绍氧化锌包覆物的制备及其在天然橡胶(NR)中的应用。采用直接沉淀法优化工艺制备以碳酸钙和碳酸镁为内核、以氧化锌为外壳、氧化锌质量分数约为0.60的氧化锌包覆物。氧化锌包覆物为球形颗粒,表面均匀覆盖长度为100 nm的六方柱状氧化锌。用氧化锌包覆物等量替代间接法氧化锌用于NR中,胶料的密度略有减小,硫化特性和物理性能基本不变。 相似文献
10.
《建筑玻璃与工业玻璃》2004,(2):33-34
洛阳浮法玻璃集团公司引进的国际最先进水平的玻璃微缺陷检测仪,正式投入运营以来,1毫米超薄玻璃总成品率达到87%,一级品率达到95%,切裁率达到85%,切裁率比世界最先进的日本厂家高出9个百分点。 相似文献
11.
室温下采用氨浸出锌灰制得碱式碳酸锌,再经煅烧制得超细氧化锌。研究了在合成碱式碳酸锌过程中表面活性剂对碱式碳酸锌和氧化锌颗粒尺寸与形貌的影响。结果表明,聚乙二醇(PEG20000)和聚乙烯吡咯烷酮(PVP-K30)这两种表面活性剂对颗粒的分散效果最好,制得的碱式碳酸锌颗粒为无定形片状且分散均匀,平均粒径为1 μm,煅烧后的氧化锌颗粒为六方晶系纤锌矿结构,粒径约为0.7 μm。添加PVP-K30比添加PEG20000的碱式碳酸锌热分解温度高。添加PEG和PVP的碱式碳酸锌反应活化能分别为139.9 kJ/mol和146.8 kJ/mol。 相似文献
12.
Field experiments with wheat were conducted for two years on flood plain alluvial soils to study the effectiveness of soil application of zinc sulphate and zinc oxide at 0, 15, 45, 60, 75 and 90 days after sowing. Yield and zinc uptake of wheat increased significantly with the application of zinc. Delaying the application of both zinc sulphate and zinc oxide up to 45 days of sowing did not adversly affect the zinc nutrition of wheat. However, delaying the application for 75 or 90 days after sowing eliminated the response. Zinc sulphate, when applied within 60 days of sowing performed better than zinc oxide. In a laboratory study, zinc sulphate maintained a higher level of zinc in the soil solution than zinc oxide at least over a 3-week period. 相似文献
13.
用锌渣制备高纯氧化锌 总被引:7,自引:0,他引:7
介绍了利用锌渣为原料生产高纯氧化锌的方法。采用黄铁矾法除去大部分铁,通过控制pH值进一步除铁,用锌粉或锌屑还原除去重金属,用氨水为沉淀剂,最终可使氧化锌的含量达99.86%以上。 相似文献
14.
15.
Electrowinning of zinc from zinc chloride solutions, acidified by HCl, was conducted in a cation exchange membrane cell. The current efficiency was correlated with the deposit morphology. The deposits having lesser surface defects, which act as active sites for hydrogen adsorption, exhibited higher current efficiency. The (1 1 0) preferred texture was observed on the deposits grown in high acid solution containing gelatin. High temperature (40 ºC) and high current density decreased the current efficiency and the preferred texture. 相似文献
16.
17.
18.
R. Renuka L. Srinivasan S. Ramamurthy A. Veluchamy N. Venkatakrishnan 《Journal of Applied Electrochemistry》2001,31(6):655-661
The behaviour of zinc and zinc oxide in 5.3 M KOH in the presence of alkaline earth oxides, SnO, Ni(OH)2 and Co(OH)2 was examined by cyclic voltammetry. The influence of the alkaline earth oxides was compared with additives of established effects (Bi2O3, LiOH, Na2CO3 and CdO). The alkaline earth oxide each exhibits a distinct behaviour towards zincate. Whereas, a single process of interaction with zincate was shown by CaO; two modes of reaction were obtained with SrO and BaO. Solid solution formation was noticed with BeO and MgO. The other additives forming solid solution with ZnO were CdO, SnO. The ionic sizes of Ni(OH)2 and Co(OH)2 allow solid solution formation with Zn(OH)2. Both Bi2O3 and Na2CO3 enter into complexation with zincate. LiOH forms two distinct zincates, of which one is an oxo zincate leaching the `hydroxyl' functionality. Cyclic voltammetry revealed the deposition of the oxide/hydroxide additives as metal prior to the onset of zinc deposition and the potential range for this additive metal deposition is almost the same for different additives (SnO, CdO, Ni(OH)2). The beneficial action of these additives to zinc alkaline cells is associated with a substrate effect. The implication of this electrocatalytic deposition of metals on a zinc oxide electrode is also discussed. 相似文献