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1.
试验研究了温度和添加剂对MoO3挥发的影响。结果表明,温度越高,MoO3挥发越激烈,1 600℃时挥发率达到13.22%。当添加CaO时,MoO3挥发率降低,1 600℃下当w(CaO)达到20%~30%时,MoO3的挥发率降低到2%左右。XRD分析结果表明,CaO与MoO3生成了CaMoO4,从而降低了MoO3的活性,因此添加CaO能有效抑制MoO3的挥发。  相似文献   

2.
氧化钼直接合金化炼钢的发展   总被引:1,自引:0,他引:1  
 介绍了氧化钼直接合金化炼钢的理论依据和电炉炼钢过程中的最佳加入时期,总结了抑制氧化钼挥发的研究成果并对比分析了国内外氧化钼炼钢工艺流程的差别。由此得出,采用氧化钙、碳酸钙、氧化镁或氧化铁和三氧化钼混加的方式能显著抑制三氧化钼的挥发,提高钼的收得率。  相似文献   

3.
添加uf-Al2O3降低镁铬砖高温挥发性的研究   总被引:1,自引:0,他引:1  
根据固相-气相挥发理论,添加uf-Al2O3能够有效地抑制再结合镁铬砖的高温挥发,保持结构稳定,提高砖的抗渣性和耐剥落性。uf-Al2O3的加入量以3%为宜。  相似文献   

4.
高溶性工业氧化钼的生产研制   总被引:1,自引:3,他引:1  
从。MoO2氧化动力学过程及热力学过程入手,对MoO2氧化成MoO3可能性及各种参数分析,对生产炉窑的选型作了分析论证,制定了高溶性工业氧化钼的生产工艺并选取了采用电磁感应加热式密闭、富氧回转窑作为高溶性工业氧化钼生产设备。经过工业试验选取了最佳生产工艺条件及各项参数。  相似文献   

5.
采用氧化钼代替钼铁直接合金化冶炼含钼钢可减少钼铁生产流程、降低成本,但氧化钼的高温挥发特性阻碍了氧化钼直接合金化技术的应用。为保证转炉采用氧化钼合金化过程取得较高的钼收得率,研究了转炉吹炼不同阶段氧化钼还原反应的热力学机理,发现炼钢温度下金属液中各元素可作为还原剂与氧化钼产生还原反应,吹炼前中期熔池中还原剂含量高,氧化钼挥发率低,此时加入氧化钼可获得较高的钼收得率。分析了氧化钼反应动力学环节,发现反应限制性环节为还原剂向氧化钼表面的扩散。在此基础上进行了高温试验,结果表明氧化钼合金化的冶金效果优于钼铁,吹炼前中期金属液中[C]、[Si]含量较高,此时进行氧化钼合金化钼收得率在95%以上。对成品钢中的夹杂物进行了分析,夹杂物主要为硫化物和氧化铝,采用氧化钼合金化不会增加钢中夹杂物。研究结果为炼钢过程采用氧化钼直接合金化冶炼含钼钢提供了理论和技术支撑。  相似文献   

6.
研究了采用空气氧化、氢氧化钠浸出、硝酸酸化工艺从废钼催化剂中回收 Mo、Co、Ni等有价金属。试验结果表明:在空气流量30 L/min、氢氧化钠加入量为金属Mo理论耗量1倍、浸出温度85℃条件下,钼浸出率达99.8%;碱浸渣用硝酸酸化、双氧水除铁,双氧水加入量为铁理论量的2~3倍,反应温度70℃;滤液用NaO H溶液调p H为9.5,镍、钴以氢氧化物形式沉淀,酸溶后,用P507萃取剂萃取分离钴、镍。该工艺采用空气氧化,避免了传统焙烧工艺MoO3的挥发损失;用NaOH浸出Mo ,生产成本降低,工艺流程简单,金属回收率较高。  相似文献   

7.
白钨矿和氧化钼直接还原合金化的理论分析及工业试验   总被引:2,自引:0,他引:2  
对白钨矿和氧化钼直接还原合金化进行了热力学和动力学计算和分析.炼钢过程中,[C]、[Si]、[Al]都能还原白钨矿和氧化钼.(WO3)和(MoO3)还原过程的限制性环节分别是WO3及MoO3在熔渣中的扩散.并成功进行了全部用白钨矿和氧化钼冶炼高速钢M2(M2Al)的工业试验.  相似文献   

8.
熔融还原法冶炼高速钢   总被引:5,自引:1,他引:5  
对用白钨矿、氧化钼和钒渣冶炼高速钢进行了热力学和动力学的计算与分析。在熔融还原过程中,CaWO4、MoO3、V2O5将被C、CaC2、Si-Fe、SiC还原。反应过程包括:固一固反应、液一固反应、铁浴反应和液一液反应。开发了低温快速还原、控制渣量、抑制沸腾等技术。还原WO3的限制性环节是WO3在熔渣中的扩散,改善渣的流动性,扩大反应界面能加快WO3的还原;使用阻尼剂能有效抑制钼的挥发。用20t的AC电弧炉还原氧化钨矿工业化生产高速钢M-2已取得成功,具有质量高、缩短工序、节约资源、降低能耗、提高成品率和改善环境等优点。综合上述功效,生产每吨M-2钢可节约成本1780元。应用这一新技术,重庆特钢公司累计生产M-2钢7981t。  相似文献   

9.
在MoO2还原为钼粉的过程中,大颗粒钼粉(指筛上物)的杂质含量会远远高于小颗粒钼粉。本文采用"核收缩"的理论模型来解释了这一现象。在MoO2氢还原为Mo的过程中,产生一种比起钼的其他化合物挥发性更强的氧化钼的水合物MoO3.H2O或MoO2(OH)2,这种水合物结合从MoO2收缩核中扩散出来的杂质,挥发沉积到长大的Mo颗粒的表面。大颗粒Mo粉的表面积大、表面能低,挥发性水合物更容易沉积在由众多细小颗粒团聚而成的大颗粒表面,从而造成大颗粒钼粉的杂质含量较高。  相似文献   

10.
采用"两段式"焙烧新工艺,即利用悬浮态焙烧技术在预反应器中脱除辉钼矿精矿中的大部分硫,然后在回转窑内脱除残余硫,在试验室模拟悬浮态装置中考察焙烧温度、焙烧时间等参数对脱硫效果的影响以及钼精矿的预反应过程。结果表明,相对于焙烧时间而言,焙烧温度对残硫量的影响相对较小;在脱硫率≤80%时,绝大部分氧化钼以MoO2形式存在,不会产生MoO3大量升华损失的情况;在焙烧温度700780℃、物料停留时间1780℃、物料停留时间13s时,悬浮态焙烧技术可以实现50%以上的表观脱硫率;相对于堆积态焙烧,脱硫效率大大提高。  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
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。  相似文献   

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13.
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。  相似文献   

14.
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.  相似文献   

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16.
The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.  相似文献   

17.
Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.  相似文献   

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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)  相似文献   

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