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21.
用硫酸铁铵容量法测定钛精矿中二氧化钛含量   总被引:2,自引:0,他引:2  
样品在过氧化钠熔融、水浸取及盐酸酸化后,在盐酸和硫酸介质中,隔绝空气,用金属铝将钛(Ⅳ)还原至钛(Ⅲ),以硫氰酸盐为指示剂,用硫酸铁铵标准溶液滴定。  相似文献   
22.
首钢外购焦炭质量恶化后的高炉生产实践   总被引:2,自引:0,他引:2  
张思斌  王涛  李颖 《炼铁》2004,23(1):18-21
针对焦炭质量劣化的状况,高炉操作以活跃炉缸为主,从上下部调剂入手,采取疏导煤气、控制合理的实际风速和鼓风动能、缓解焦炭在高温区的粉化等措施,有效地改善了高炉的顺行状况,并逐步恢复高炉指标。  相似文献   
23.
安阳化学工业集团公司(以下简称安化集团)现有2套200 kt/a尿素装置及1套60 kt/a甲醇装置.尿素及甲醇装置在生产过程中会产生大量的尿素解吸废液和甲醇残液,废液中的氨氮(NH3-N)含量和化学需氧量(CODCr)较高,给该公司废水的达标排放带来很大压力.  相似文献   
24.
25.
杨恩林  张杰 《中国陶瓷》2008,44(5):35-37
研究了用黄磷渣代替部分粘土作陶瓷原料,既可以解决磷渣对环境的污染和堆放占用耕地问题,使该固体废弃物资源化,又能缓解陶瓷原料的短缺。  相似文献   
26.
前言 近20年来,随着改革开放和国民经济的飞速发展,我国建筑卫生陶瓷行业也得到快速发展,产量连年增长,成为世界上建筑卫生陶瓷的最大生产国和消费国,也是出口大国.2007年全国卫生陶瓷的产量达到15 000万件,占世界产量的40%,出口量达到5 525万件,占产量的40%.  相似文献   
27.
The cooling and solidification of melted drops during their movement in an immiscible cooling medium is widely employed for granulation in the chemical industry, and a study of these processes to provides a basis for the design of the granulation tower height and the temperature of the cooling medium is reported. A physical model of the cooling and solidification of the drop is established and the numerical calculation is performed. The influences of the key factors in the solidification, i.e., Bi number, drop diameter, temperature of the cooling medium, etc. are presented. The cooling and solidification during wax granulation in a water‐cooling tower and during urea granulation in an air‐cooling tower (spraying tower) are described in detail. Characteristics of the solidification and temperature distribution within the particle at different times are shown. The model and calculations can be used for structure design of the granulation tower and optimization of the operation parameters.  相似文献   
28.
Carboxyl‐terminated butadiene‐acrylonitrile rubber (CTBN) has often been used to improve the toughness of cyanate ester (CE) resin while sacrificing modulus and thermostability. In this paper, the addition of the appropriate amount of epoxy resin (EP) to the CE/CTBN system is shown to not only increase the modulus and thermostability of the blend, but also improve the toughness. The values of impact strength showed a maximum for the CE/CTBN/EP 100/5/5 blend. The temperature of 10 % weight loss (T10) improves from 376 °C for CE/CTBN 100/5 to 407 °C for the CE/CTBN/EP 100/5/2.5 blend. It is proposed that addition of the appropriate amount of EP can decrease the mobility and increase the stability of CTBN via the reaction between the terminal carboxyl group of CTBN and the hydroxyl group of EP. But a very high EP concentration will decrease the crosslinking density of CE, consequently reducing the mechanical properties and thermostability of the blends. Copyright © 2004 Society of Chemical Industry  相似文献   
29.
From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry  相似文献   
30.
Poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐para‐phenylene vinylene] (MEH‐PPV)/silica nanoparticle hybrid films were prepared and characterised. Three kinds of materials were compared: parent MEH‐PPV, MEH‐PPV/silica (hybrid A films), and MEH‐PPV/coupling agent MSMA/silica (hybrid B films), in which MSMA is 3‐(trimethoxysilyl) propyl methacrylate. It was found that the hybrid B films could significantly prevent macrophase separation, as evidenced by scanning electron and fluorescence microscopy. Furthermore, the thermal characteristics of the hybrid films were largely improved in comparison with the parent MEH‐PPV. The UV‐visible absorption spectra suggested that the incorporation of MSMA‐modified silica into MEH‐PPV could confine the polymer chain between nanoparticles and thus increase the conjugation length. The photoluminescence (PL) studies also indicated enhancement of the PL intensity and quantum efficiency by incorporating just 2 wt% of MSMA‐modified silica into MEH‐PPV. However, hybrid A films did not show such enhancement of optoelectronic properties as the hybrid B films. The present study suggests the importance of the interface between the luminescent organic polymers and the inorganic silica on morphology and optoelectronic properties. Copyright © 2004 Society of Chemical Industry  相似文献   
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