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1.
简谈预浸     
列举实例,提出了对预浸的看法,在多数情况下,预浸能取得较好的电镀效果。  相似文献   

2.
较系统地介绍了溶浸采矿法的堆置浸矿法,就地破碎溶浸采矿法,原地溶浸采矿法的国内外应用情况,同时分别阐述了它们的发展方向。  相似文献   

3.
浸渗技术     
本文概述了浸渗技术发展概况,并对浸渗技术的三要素:浸渗剂、浸渗工艺与浸渗设备作了介绍,列举了应用实例。  相似文献   

4.
本文根据复合材料低成本制造技术,介绍了预浸料技术的新进展,包括可常温储存的预浸料;低温固化温使用的预浸料;大丝束碳纤维预浸料和快速固化预浸料。  相似文献   

5.
钴钼废催化剂回收钼的方法   总被引:1,自引:0,他引:1  
针对从钴钼废催化剂中提取钼现今比较普遍的几种方法,通过对它们的实验原理、工艺流程、回收率、经济效益等方面的比较,认为氢氧化钠碱浸法在多方面具有优势,是回收钼的首选方法。  相似文献   

6.
对用于浸渍石墨的三种磷酸的浸渍剂的配制,浸渍和热处理工艺以及氧化过程进行了研究,结果表明磷酸盐可明显提高石墨材料的抗氧化性能,经三种浸渍剂处理过的石墨材料分别在700℃,800℃和900℃以下基本不氧化。  相似文献   

7.
氨浸 - 碳化法制活性氧化锌   总被引:3,自引:0,他引:3  
对以菱锌矿为原料,用硫化碱为除杂剂,二氧化碳为沉锌剂的活性氧化锌制备方法进行了研究,重点考察了除杂和碳化沉锌过程的工艺条件,实验得出,除杂时硫化碱加入量为理论量的120%较好;碳化沉锌终点定在pH值为8时较为适宜;碳化时采用较低的温度,较高的二氧化碳浓度和较高的空塔气速(0.04-0.05m/s)为宜。  相似文献   

8.
预浸料技术的新进展   总被引:2,自引:0,他引:2  
本文根据复合材料低成本制造技术,介绍了预浸料技术的新进展,包括可常温储存的预浸料;低温固化高温使用的预浸料;大丝束碳纤维预浸料和快速固化预浸料。  相似文献   

9.
湿法冶金提纯废弃焦粉的热力学研究   总被引:1,自引:0,他引:1  
湿法冶金反应过程中的热力学研究可以揭示反应过程中反应热变化规律、反应进行的可能性以及反应自动进行的条件。选用云南某地产出的废弃焦粉作为研究对象,对其采用湿法冶金两段浸出过程进行了热力学分析。研究结果为采用湿法冶金方法降低废弃焦粉灰分含量的实验研究提供理论依据。所获得优质焦粉经造球成型后,作为冶金、化工(主要指电石)等行业替代还原剂使用具有较好的应用前景。  相似文献   

10.
邓范君  陈文良 《炭素》1997,(2):38-40,33
对浸铝合金炭石墨制品变形,开裂等原因进行了分析和探讨,从而提出了减少变形的一些实验可行的措施。  相似文献   

11.
以正己烷为溶剂,提取烟草中的茄尼醇,在浸提工艺前,引入氨浸预处理技术来有效增强提取效果。综合运用组分分析、液质联用、扫描电镜等技术分析了氨浸预处理的必要性和氨浸预处理机制。结果表明,氨浸预处理可以有效脱除木质素,破坏烟草细胞壁结构,促进茄尼醇释放,并可对茄尼酯进行水解皂化生成游离态茄尼醇,同时溶解部分杂质,从而强化茄尼醇的提取效果,简化后续纯化过程。提取对比实验表明,对烟叶原料进行氨浸预处理后,提取平衡时间从3 h缩短至1.5 h,茄尼醇提取率从89.24%±1.54%提高到104.63%±2.44%,浸膏纯度从16.72%±0.6%提高到21.03%±0.6%,效果显著。该法可为其他天然产物的提取工艺开发提供新的思路和方法。  相似文献   

12.
This paper reports a study in the wet tropics of Queensland on the fate of urea applied to a dry or wet soil surface under banana plants. The transformations of urea were followed in cylindrical microplots (10.3 cm diameter × 23 cm long), a nitrogen (N) balance was conducted in macroplots (3.85 m × 2.0 m) with 15N labelled urea, and ammonia volatilization was determined with a mass balance micrometeorological method. Most of the urea was hydrolysed within 4 days irrespective of whether the urea was applied onto dry or wet soil. The nitrification rate was slow at the beginning when the soil was dry, but increased greatly after small amounts of rain; in the 9 days after rain 20% of the N applied was converted to nitrate. In the 40 days between urea application and harvesting, the macroplots the banana plants absorbed only 15% of the applied N; at harvest the largest amounts were found in the leaves (3.4%), pseudostem (3.3%) and fruit (2.8%). Only 1% of the applied N was present in the roots. Sixty percent of the applied N was recovered in the soil and 25% was lost from the plant-soil system by either ammonia volatilization, leaching or denitrification. Direct measurements of ammonia volatilization showed that when urea was applied to dry soil, and only small amounts of rain were received, little ammonia was lost (3.2% of applied N). In contrast, when urea was applied onto wet soil, urea hydrolysis occurred immediately, ammonia was volatilized on day zero, and 17.2% of the applied N was lost by the ninth day after that application. In the latter study, although rain fell every day, the extensive canopy of banana plants reduced the rainfall reaching the fertilized area under the bananas to less than half. Thus even though 90 mm of rain fell during the volatilization study, the fertilized area did not receive sufficient water to wash the urea into the soil and prevent ammonia loss. Losses by leaching and denitrification combined amounted to 5% of the applied N.  相似文献   

13.
电解锰渣中氨氮是限制其综合利用的主要因素,草酸浸取可高效脱除电解锰渣中氨氮。本文研究影响电解锰渣氨氮浸出的工艺条件,通过FT-IR、XRD、XPS、SEM和EDS等技术表征物质变化,通过动力学分析和热力学计算建立氨氮浸出模型、探讨浸出机理。结果表明:用浸取-洗渣二级洗涤工艺,在液固比为2、草酸用量为10%、浸取时间为20 min时,氨氮剩余浓度13.85 mg/L,除氨率达98%。电解锰渣磷酸铵盐主要存在于难溶的硫酸钙晶格中,草酸促进硫酸钙晶格间磷酸铵盐的释放。氨氮浸出速率受化学反应和界面传质混合控制,铵根离子与草酸分子1∶1配位时释放能量最多,结构最稳定。  相似文献   

14.
锌冶金渣尘作为一种重要的锌二次资源,来源广、储量大、具有较高的综合回收利用价值。以NH3-CH3COONH4-H2O为浸出体系,考察粒度、反应时间、搅拌速度、液固比、总氨浓度、NH3与NH4+物质的量比和温度对锌浸出率的影响,结果表明:控制浸出温度为25 ℃、总氨浓度为5 mol/L、液固体积质量比为5 mL/g、n(NH3)/n(NH4+)=1:1、搅拌速度为300 r/min、浸出时间为60 min,在此条件下锌的浸出率可达84%。含锌冶金渣尘浸出动力学分析显示,浸出反应表观活化能为22.66 kJ/mol,锌浸出过程的浸出速率受固体膜层扩散及界面化学反应共同控制,并获得了浸出锌的动力学速率方程。  相似文献   

15.
The experiments of agitation leaching were carried out in aqueous ammonia/ammonium carbonate solution, to recover copper from the flotation tailings of waste copper oxide residue. The main copper minerals contained in the flotation tailings are chrysocolla, malachite, and cuprite, with the copper grade of 1.12%. Effects of lixiviant concentration, solid‐to‐liquid ratio, stirring speed, and reaction temperature on copper leaching ratios at various time were investigated. It is found that the leaching ratio almost cannot be affected by time after 90 min of leaching. The optimised processing conditions have been determined, under which the leaching ratio of 70.6% is obtained. Kinetics analysis indicates that the copper leaching ratio is controlled by diffusion through the product layer in the initial 60 min of leaching, and corresponding measures to strengthen the copper extraction is proposed, with the activation energy of 32.3 kJ/mol. © 2012 Canadian Society for Chemical Engineering  相似文献   

16.
房祥华  安莲英  唐明林  黄硕 《江苏化工》2008,36(5):23-25,30
主要研究了冶炼废渣中铜、锌的浸出,通过对废渣成分的分析选择了氨性浸出,首先通过四因素三水平的正交试验得到了氨性浸出的优化条件:石灰用量5%,碳酸氢铵用量30%,固液质量比为1:4,浸出时间为36 h,铜、锌的浸出率分别为58.6%和42.6%,由正交试验可以看出碳酸氢铵用量为显著因素.然后考察了石灰用量、碳酸氢铵用量、固液比、浸出时间以及氧化剂5个因素对铜锌浸出的影响,优化了氨性浸出的条件,在石灰用量5%,碳酸氢铵用量30%,固液质量比1:4,浸出时间36 h,氧化剂(次氯酸钠)用量6%的条件下铜、锌的浸出率分别为76.4%和63.4%.对同一矿样多次浸出铜、锌浸出率分别达到90.1%和84.1%.  相似文献   

17.
研究了高碳镍钼矿制备钼酸铵的工艺,通过氧化酸浸分离镍、钼,制得高品位的钼酸浸出渣。通过单因素、正交实验以及优化实验的探究,确定了氨浸的最佳工艺参数:液固比3∶1,反应温度60℃,反应时间2 h,氨的过量系数为1.6,碳酸氢铵与钼的质量比为0.1,钼的浸出率达98%以上。将氨浸液调节pH、搅拌、加晶种、陈化后析出浅绿色的钼酸铵晶体,产品质量符合GB/T 657-1993标准,钼的总产率达90.67%。  相似文献   

18.
以大洋锰结核经氨浸工艺提取钴、镍、铜等金属后的粉末状固体残渣(氨浸渣)为颜填料、与水混合制成色浆,再与苯丙乳液和辅助原料混合,制备水性防锈涂料。色浆组成(质量分数,下同)为:氨浸渣55.15%,水42.63%,辅助原料2.22%;防锈涂料配方为:色浆60%,苯丙乳液30%,辅助原料10%。防锈涂层的抗冲击强度≥490N·cm,耐盐水性超过21d。研究表明:氨浸渣富含Fe2O3,对被保护物品具有屏蔽和物理防锈作用。氨浸渣中的Zr,Zn等元素可与受腐蚀的铁或与环境中的SO42-反应,生成惰性氧化物或难溶化合物,具有化学防腐作用。氨浸渣中的稀土元素和锰能促进漆膜分子网络交联,可缩短涂层的固化成膜时间,并提高涂膜的强度和耐水性。  相似文献   

19.
氨配合法制备活性氧化锌过程研究   总被引:3,自引:0,他引:3  
以粗氧化锌为原料,用氨水-碳酸氢铵作浸取液,经粗氧化锌溶解,除杂净化,蒸氨结晶,洗涤脱水,干燥,煅烧可制得活性氧化锌,有本文方法制得的活性氧化锌的质量符合HG/T72572-94标准。  相似文献   

20.
A hydrometalhirgical process to extract silver from the silver-lead ore in Boorchi, Mongolia by using thiourealeaching solution is studied in this work. Through the observation of optical and scanning electron microscopes, and energyspectral analysis, it is determined that 5 kinds of silver minerals exist in the ore, including argentite, Ag-tetrahedrite,Ag-Zn-Sb-tetrahedrite, freibergite and acanthite. The experimental results of direct thiourea leaching of the ore show that56%~60% of silver is leached. The main reason for the low leaching rate is due to silver minerals enveloped in galena andother minerals, even though the ore is ground to the particle size of 75 μm. When the ore is pretreated with ammoniumcarbonate solution under oxidation, the experimental results of thiourea leaching show that the leaching rate of silver increasesto near 75% with the pretreatment. Based on the leaching experiments, a principle hydrometallurgical technological route toextract silver from the Ag-Pb ore is proposed.  相似文献   

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