从失效催化剂中回收钯的试验研究

研究了采用氧化焙烧—还原—氯化浸出工艺流程从失效催化剂中回收钯,考察了焙烧温度、焙烧时间、还原剂种类及用量、氧化剂种类、盐酸浓度等对钯浸出率的影响。试验结果表明,失效催化剂在575℃下焙烧2h,控制还原剂水合肼(N2H4·H2O)用量为2.5g/L,以氯酸钠(NaClO3)作氧化剂(用量为3.0g/L),用5mol/L的盐酸进行浸出,钯浸出率在98%以上,二段浸出后,钯总回收率达99%以上。     

从抛光废料中回收稀土的研究

探索了从抛光废料中回收稀土并确保稀土回收率在80%以上的工艺.通过分析现有抛光废料成分,有针对地提出了初步回收其中稀土成分的方法.整个试验过程分为两部分,小试主要探索原料前处理方式、酸的种类、酸的浓度、浸出温度、浸出时间和添加剂种类等因素对抛光废料中稀土回收率的影响.试验最佳条件为:加入添加剂B,用8 mol/L的盐酸在92℃下直接浸出2 h.经过除杂、萃取分离、沉淀、灼烧工序后,稀土回收率最高可达85.94%.然后根据小试确定的最佳条件进行综合扩试,所得稀土回收率能稳定在81%以上.初步概算,处理1 t该废料收益可达2000元左右.      

从废荧光粉中回收稀土的工艺研究

研究了从废荧光粉(REO^12.00%)中回收稀土元素的工艺。采用碳酸钠焙烧-酸浸出工艺回收废荧光粉中的稀土,研究了碳酸钠加入量、焙烧温度、焙烧时间以及浸出条件对稀土回收率的影响。研究结果表明,碳酸钠焙烧试验的最佳条件为碳酸钠与荧光粉焙烧比例1∶2,焙烧温度700℃,焙烧时间1 h;焙烧产物用盐酸浸出,浸出试验最佳条件:盐酸浓度、液固比、浸出温度、浸出时间分别为3 mol/L、10∶1、70℃、2 h,在上述焙烧及浸出最优条件下,稀土总回收率(REO)达97%以上。     

灼烧还原容量法测定钯有机物中钯含量

试样通过马弗炉灼烧分解有机物,将灼烧残留物用水合肼还原后,用硝酸-盐酸(1+3)混酸溶液溶解,采用EDTA络合丁二肟析出硝酸锌返滴定测定钯含量。考察了试样中有机成分的分解条件和氧化钯还原条件,以及滴定干扰因素。与丁二肟重量法比对所得结果一致,加标回收率99.67%~100.02%,相对标准偏差(RSD)为0.25%~0.29%。建立了一种快速、简便、准确的钯有机物容量分析方法。     

金属铂加压氰化溶解动力学实验研究

室温加压下金属铂不能被氰化钠溶解是动力学因素, 高温加压氰化已应用于含铂族金属的废催化剂和含铂钯硫化物浮选精矿的铂钯提取. 研究了高温加压氰化金属铂溶解的各种因素. 实验结果表明, 温度越高, 越有利于铂溶解. 搅拌速率对金属铂的溶解基本无影响, 氰化钠浓度越大, 金属铂溶解的速度越快, 氧的分压增大铂溶解降低. 转速600 r·min-1. 温度180 ℃左右, 氰化钠浓度12.5 g·L-1, 氧的分压1.0 MPa和2 h时间以内易于铂溶解.     

报废汽车高值元器件的氧化浸出试验

以报废汽车高值元器件废催化剂为原料,探讨了铂、钯、铑的浸出条件。分别研究了氧化浸出过程中盐酸浓度、时间、温度、氯酸钾百分比、固液比等对铂、铑、钯浸出率的影响。结果表明,较佳浸出工艺条件为:盐酸浓度9mol/L、反应时间2h、反应温度90℃、氯酸钾百分比5%、固液比0.20g/mL、搅拌速率400r/min,在上述工艺条件下,铂、钯、铑的浸出率分别为95.15%、96.44%、83.30%。     

用盐酸从独居石“碱饼”中溶解铀、钍及稀土

研究了用盐酸溶液从独居石精矿碱分解产物"碱饼"中溶解铀、钍及稀土,考察了盐酸用量、溶解温度、液固体积质量比、溶解时间等因素对铀、钍及稀土溶解率的影响。试验结果表明:在盐酸用量135%、余酸浓度0.3mol/L、液固体积质量比2∶1、溶解温度20℃、溶解时间5h条件下,"碱饼"中铀、钍及稀土的溶解率分别为91.88%,93.49%,93.64%;"碱饼"中磷的含量对盐酸溶解铀、钍和稀土有重要影响。     

活性炭吸附富集原子吸收光谱法测定矿石中的金

试样在660℃左右灼烧除硫,先用盐酸再用王水溶解,用活性炭吸附富集矿石中的金,在800℃将活性炭灰化、灼烧,金被还原成单体金,再以王水溶解,用火焰原子吸收法直接测定。该方法提高了测定金的准确性和灵敏度,降低了捡出限,相对标准偏差小于6.0%,回收率在99%以上。     

正交实验法研究煤矸石中镓的提取工艺条件

采用正交实验法探讨了煤矸石中镓的提取工艺条件。实验采取了高温酸性浸出法,用正交实验方法设计实验工艺条件。探讨了酸的浓度、灼烧温度、灼烧时间、酸浸温度、酸浸时间等多个因素对镓提取率的影响,得到提取镓的较优工艺条件。即酸的浓度为6 mol/L,灼烧温度为600℃,灼烧时间0.5 h,酸浸温度为100℃,酸浸时间为6 h。使提取率达95%以上,为煤矸石中镓的提取提供了可行的实验条件。     

从含钌废料中分离提纯钌工艺研究

研究采用化学溶解—草酸还原法从含钌废料中分离提纯钌,考察固液质量体积比(m(含钌物料)∶V(NaOH溶液)∶V(NaClO溶液))、溶解温度、溶解时间、草酸还原过程中金属钌与草酸质量比、反应温度、反应时间对钌回收率的影响。结果表明:在固液质量体积比1∶6∶30、溶解时间5h、溶解温度80℃溶解条件下,及钌与草酸质量比1∶5、反应温度70℃、反应时间50min草酸还原条件下,钌回收率为97.7%,回收效果较好。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Rehabilitation of disorders of the breaking of voice

The adolescent's breaking of the voice is the result of the substitution of the chest voice (or heavy mechanism) for the head voice (or light mechanism). In cases of late breaking, the voice is abnormally high-pitched and feeble, often with a distorted timbre, while the larynx is normal and pubescent. Such people are generally not fully aware of their voices' real nature. Therapy classically resorts to laryngeal manipulations, of which a new technique is put forward. Another therapeutic approach is based, on the one hand, on critical listening compared with a control male voice, thus enabling the subject to become aware of his own voice, and, on the other hand, on high intensity work which helps passing from head to chest voice.