氟化钙在磷酸铵-氨水溶液中的溶解行为研究

磷酸铵、氨水和氟化钙混合高压浸出白钨矿生成氟磷酸钙,并一步得到钨酸铵溶液,避免了传统氢氧化钠分解-离子交换转型工艺带来的废水污染,是实现白钨绿色冶炼的有效途径.氟化钙作为固体氟源,其在浸出过程的溶解一定程度上决定了白钨的分解效果.为此,研究了氟化钙在磷酸铵-氨水混合溶液中的溶解行为.考察了磷酸铵用量、氨水浓度、温度、保温时间和液固比对氟化钙浸出率的影响.实验结果表明:随磷酸铵用量和保温时间的增大,氟化钙浸出率逐渐增大;随氨水浓度、温度和液固比的增大,氟化钙浸出率先增大而减小.当磷酸铵用量为理论量的25倍、氨水浓度为3 mol/L、温度为180℃、液固比(指质量比,下同)为50∶1以及保温时间为180 min时,氟化钙浸出率达到91.1%.     

废弃稀土抛光粉再生利用的研究

通过对废弃稀土抛光粉再生利用的研究发现,以浓硫酸为浸出液时,硫酸和废弃抛光粉质量比为1.5,浸出反应温度160℃,浸出时间3 h时,稀土的浸出率达到92.3%。通过扫描电镜发现稀土氧化物随着煅烧温度的升高粒径逐渐变小。在550℃时,稀土氧化物晶体开始形成小颗粒有规则的晶体。对抛光粉的抛光性能研究发现,再生抛光粉比市售的抛光粉性能要好。氧化铈含量为85.37%的再生抛光粉,抛光60 min,抛蚀量可以达到437nm/min,并随着再生抛光粉的氧化铈含量的增加会提高打磨性能。     

废旧镍氢电池负极板中稀土的回收

采用湿法冶金工艺,回收废旧镍氢电池负极板中的稀土（RE）元素,用硫酸浸出负极板中的有价金属,分析硫酸浓度、浸出温度、浸出时间等因素对稀土元素浸出率的影响,在硫酸浓度为2.0 mol/L、浸出温度为60℃、浸出时间120 min下,RE的浸出率为92.31%.采用磷酸二异辛酯（P204）为萃取剂萃取浸出液中的稀土,当P204在煤油中的比率为20%时,萃取率为92.86%.用硫酸钠沉淀溶液中的稀土,浸出液中稀土元素回收率可达98.78%.采用XRD和SEM分析表征回收的稀土氧化物的物相和表面形貌,结果表明,回收产物为铈系稀土氧化物,为立方晶系,呈面心立方结构,表面形貌为棱柱形.     

废弃荧光粉浸出液中稀土的沉淀工艺研究

本文研究废弃的荧光材料稀土沉淀过程,考察不同沉淀剂、不同沉淀剂浓度、不同陈化时间及不同沉淀反应温度对废弃的荧光材料中稀土沉淀率和稀土氧化物在沉淀中的纯度的影响。实验结果表明:草酸和碳酸氢铵的沉淀率在合适的沉淀条件下,所以实验选用碳酸氢铵和草酸都可以作为废弃的荧光材料中稀土的沉淀剂。草酸浓度70g/L、陈化时间3h,此时稀土沉淀率较高为90.804%;在60℃用碳酸氢铵沉淀废旧荧光粉中稀土的最佳工艺条件为:碳酸氢铵浓度1.0mol/L、陈化时间3h,此时稀土沉淀率较高为89.844%。如果考虑纯度,草酸作为沉淀剂,焙烧后沉淀中的稀土氧化物的纯度没有碳酸氢铵的高。所以选择碳酸氢铵作为沉淀剂会更适宜。不同反应温度下稀土的浸出率不同,随着温度升高,稀土浸出率也升高。     

某离子型稀土矿浸出试验

以中国南方地区某离子型稀土矿为研究对象,采用搅拌浸出和柱浸的方式,研究不同条件下矿样中稀土及杂质元素的浸出情况,为离子型稀土矿产资源的绿色高效开采提供参考。结果表明,浸出液固比对离子相稀土浸出率影响较大,浸出时间影响较小,离子相稀土浸出过程时间短,反应迅速;柱浸过程中离子相稀土流出速率最快,达到平衡时间短,杂质元素前期浸出浓度高,后续拖尾严重;离子相稀土浸出率随着样品深度的增加不断降低,符合南方离子型稀土成矿规律;硫酸铵浸出过程中铵根离子损失量较大,最低损失率超过11.31%,硫酸根不参与金属离子的交换反应过程,回收率最高可达99.22%。     

柠檬酸盐配位浸出风化壳淋积型稀土矿回收稀土的研究

选用柠檬酸盐作为风化壳淋积型稀土矿的浸取剂,并将柠檬酸盐对稀土的浸出效果与硫酸盐和氯化盐等浸取剂进行了对比,考察了柠檬酸铵作为浸取剂时的最佳浸取工艺。实验结果表明,柠檬酸铵作为风化壳淋积型稀土矿浸取剂时,柠檬酸根离子与稀土离子的配位作用,能促进矿石稀土离子交换,提高稀土回收率,降低浸矿剂铵盐的用量,减小氨氮废水的污染。采用柱浸回收稀土的最佳工艺条件为:柠檬酸铵浓度3 g/L,液固比2∶1,浸取剂pH 6.0~8.0,淋洗流速0.5 min/m L,稀土浸出率可达90.01%。     

催化剂污泥中稀土浸出及其动力学研究

以催化废水治理产生的污泥为原料,用盐酸浸出污泥中的稀土,进行了浸出酸度、固液比、浸出温度等条件对浸出率的影响以及稀土浸出过程中动力学研究,结果表明,浸出酸度、固液比对稀土浸出率影响较大,温度的影响较小,在初始的30 min内,盐酸浸出污泥的反应已经完成,在随后的时间内,污泥的反应虽然仍在进行,但是浸出率的增加极小,固定盐酸的浓度为2 mol/L时,浸出反应的浸出过程受到固体内扩散的控制,反应的表观活化能为4.11 k J/mol。     

离子型稀土矿浸出过程主要物质浸出规律研究

采用柱浸法研究硫酸铵浸取离子型稀土矿过程中水、稀土、硫酸铵及其他杂质离子的浸出规律. 研究表明,离子型稀土矿矿土对水有较强的吸附能力,浸矿后,矿土的含水率由17.74 %增加到33.7 %.浸出过程中,稀土浸出率可达99.98 %,杂质中Al3+浸出量比较大,SiO₃2-浸出量较小,而Fe3+几乎不浸出,各离子的浸出先后顺序为:SiO₃2-、RE3+、Al3+、Fe3+,杂质Al3+的浸出略滞后于稀土的浸出. Al3+、Fe3+浓度达到峰值时,pH值最低,随着浸矿剂和顶水的加入,浸出液的pH值开始上升,直至达到硫酸铵溶液的pH值和顶水的pH值.      

萤石在HCl-AlCl_3体系的解离反应研究

萤石是包头稀土矿物中的一种重要伴生矿物,在研究包头稀土精矿络合浸出工艺理论过程中发现萤石对络合解离过程影响较大,针对萤石矿在HCl-AlCl3体系中的解离反应规律展开了深入研究。分别探讨了反应温度、反应时间、液固比、HCl浓度、Al Cl3浓度等条件对萤石解离过程的影响。结果表明:液固比、HCl浓度和Al Cl3浓度对萤石分解影响较大,确定了萤石最佳的分解工艺参数为:反应温度90℃、反应时间40 min、液固比20∶1、HCl浓度3. 0 mol·L-1、Al Cl3浓度1. 7 mol·L-1。此时萤石的分解率达到95. 4%。通过条件实验的研究掌握了萤石在HCl-AlCl3体系中的分解规律,通过X射线衍射(XRD)物相分析确定浸出渣的主要成分是Si O2,扫描电镜(SEM)和能谱分析(EDS)分析发现含铁化合物已经被分解进入溶液,矿物粒度对分解过程也存在一定影响。     

超声波强化浸出高品位混合稀土精矿

针对目前混合稀土精矿提取稀土工艺过程中存在的稀土浸出率低、浸出时间长、产品纯度低、"三废"污染严重等问题,采用超声波强化浸出过程,利用化学分析、X射线衍射(XRD)等实验手段表征了酸浸过程中HCl浓度、固液比、酸浸时间、酸浸温度、超声频率对稀土提取过程的影响。实验结果表明:当HCl浓度为7 mol·L-1、固液比为1∶3.77、酸浸时间为50 min、酸浸温度为60℃、超声功率为70 W时,稀土浸出率和Ce浸出率可以达到64.01%和69.26%;稀土浸出率和Ce浸出率均比无超声波强化浸出分别提高了24.40%和26.91%;当反应时间延长至180 min,无超声波强化浸出的稀土浸出率和Ce浸出率与反应时间为50 min时的超声强化浸出基本相同,但超声强化浸出的反应时间相比无超声波强化浸出的反应时间却缩短了72.22%,超声波对于混合稀土精矿的浸出具有明显的强化作用。     

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。     

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。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.