提高化工工艺学教学质量的几点探索

针对化工工艺学教学中存在的普性问题,从课程本身的内容和特性出发,采用归纳性、创新性、理论性、前沿性教学方法,增加教学的知识性、趣味性、连贯性,提高学生的使命感和认知感,增进了教学效果,提高了教学质量.     

酰氯的合成方法及其应用新进展

以羧酸和酰化试剂为原料进行反应,是现今合成酰氯的主要方法。根据酰化试剂的不同,系统地介绍了三氯化磷法、五氯化磷法、氯化亚砜法、光气法、固体光气法和四氯化碳法。同时对酰氯作为中间体在医药、农药、资源环境等方面的研究和应用进行了相应的介绍和展望。     

Flotation of aluminosilicate minerals using alkylguanidine collectors

The flotation mechanism of aluminosilicate minerals using alkylguanidine collectors was studied through flotation experiments, Zeta potential measurements and FT-IR spectrum analysis. It is shown that kaolinite, illite and pyrophyllite all exhibit good floatability with alkylguanidines as collectors at pH 4-12. The flotation recoveries rise with the increase of the carbon chain length. Isoelectric point(IEP) is determined to be 3.5, 3.0 and 2.3 for kaolinite, illite and pyrophyllite, respectively. However, it is anomalous that the presence of cationic collectors has less influence on the negatively charged mineral surfaces. It is explained by the special structure of guanidine which is one of the strongest bases, having two -NH2 groups. One of them maybe interacts with minerals by electrostatic forces, and the other maybe forms hydrogen bonding with OH- ions on the aluminosilicate surfaces or in the aqueous solution, increasing the density of negative charge on the aluminosilicate surface and leading unpronounced positive charge to increase on the aluminosilicate. By combining the flotation tests, Zeta potential and FTIR measurements above, the interaction mechanism can be concluded. The simultaneous presence of cationic and neutral amine groups makes it possible for SAG cation to bind on three aluminosilicate minerals by both electrostatic attraction and hydrogen bonding. While in acidic medium, the interaction of the alkylguanidines on the aluminosilicate surfaces is mainly by means of electrostatic force and hydrogen bond; in the alkaline medium, it is by the way of electrostatic effect and hydrogen bond.     

中碱度条件下乙氧羰基硫脲浮选分离铜硫

对乙氧羰基硫脲和丁黄药组合捕收剂方案浮选德兴铜矿进行了小型和工业试验研究.结果表明,与丁黄药单一捕收剂方案相比,组合捕收剂方案可使石灰用量降低2/3,实现铜铁混合精矿在pH值为10.5左右的高效浮选分离,显著提高矿山铜、金和钼的回收率.采用普遍化微扰理论和密度泛函B3PW91/6-31G(D)计算对上述实验结果进行了理论分析.ECTU的反应中心为硫代羰基中的硫原子,ECTU的最高占据分子轨道与次最高占据分子轨道的能量接近,主要由硫代羰基中的硫原子组成.ECTU的最低未占据分子轨道由官能团-O-C(=O)-N-C(=S)-N-中各原子的pz轨道组成,为一大π键,具有强烈接受和分散电子对的能力.ECTU易与表面电子组态为(t2g)6(eg)3Cu(Ⅱ)或t6e4 Cu(Ⅰ)的硫化铜矿物形成正配键和反馈键,而难与表面电子组态为(t2gа)3(egа)2 Fe(Ⅲ)或(t2g)6Fe(Ⅱ)的硫化铁矿物作用.UV和FTIR光谱结果进一步证实了ECTU对铜矿物具有优异的捕收能力,对硫矿物具有较好的选择性.     

十二烷基胍对铝硅矿物的浮选分离

采用含有胍基的长碳链季铵盐作捕收剂,研究-水硬铝石、高岭石、叶腊石和伊利石单矿物的浮选行为、铝硅人工混合矿样的浮选分离以及河南铝土矿的精选.结果表明:在捕收剂用量为2×10-4mol/L条件下,在广泛的pH范围内,十二烷基胍对硅酸盐矿物具有较好的捕收能力,平均浮选回收率可达80%;强碱性条件下,一水硬铝石的浮选回收率从80%急剧下降至20%,与高岭石、叶腊石和伊利石之间形成较大差异:以十二烷基胍为捕收剂可望实现铝硅矿物反浮选分离:实际铝土矿(原矿铝硅比为5.70)经过反浮选脱硅,精矿铝硅比达11.08,铝浮选回收率为75%;与传统的阳离子捕收剂十二胺相比,胍类阳离子捕收剂对硅酸盐矿物浮选能力强、受pH的影响小,是一种新型高效的铝硅矿物浮选分离捕收剂.     

Effect of N-substituents on performance of thiourea collectors by density functional theory calculations

Using density functional methods, some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges, which are related to the reactive behavior of thioureas containing different N-substituent groupings. The calculation results indicate that the N-substituent groupings have significant effect on the flotation performance of thiourea collectors. The order of electron-donating ability is N-propyl-N′-benzyl-thiourea (PBZYTU)＞N-propyl-N′-ethyl-thiourea (PETU) ＞N-propyl-N′-allyl-thiourea (PALTU)＞＞ N-propyl-N′-acetyl-thiourea (PACTU) ＞N-propyl-N′-ethoxycarbonyl- thiourea (PECTU) ＞N-propyl-N′-benzoyl-thiourea (PBZOYTU), and the order of feedback-electron-accepting ability is PBZOYTU＞PACTU＞PECTU＞＞ PALTU＞PETU＞PBZYTU. This implies that PBZOYTU, PACTU or PECTU can react with copper atoms having (t2g)6(eg)3Cu(II) or t6e4Cu(I) configuration on the surfaces of copper sulfide minerals through normal covalent bond and back donation covalent bond, and exhibit excellently collecting performance for copper sulfide minerals. These are consistent with the experimental data reported in the literatures.     

我国文化贸易在金融危机背景下的发展对策探讨

所谓文化贸易就是以文化传播为主体的贸易,是以文化产业为基础的。文化传媒包括传媒出版、旅游、影视等各个领域。正因为如此,文化贸易才具有多样性。随着经济的迅速发展,各行各业呈现欣欣向荣的景象,随着人们生活水平的提高,精神层次的追求也步入新的台阶,文化贸易因此大放异彩。尤其是在金融危机的背景下,文化贸易的发展显得更加突出。本文将主要对我国文化贸易的现状进行分析,就如何在金融危机的背景下促进文化贸易的发展进行探讨。     

钢筋混凝土板冲切破坏机理的试验研究及冲切承载力计算

本文研究了钢筋混凝土板的冲切破坏机理，试验中采用了较先进的混凝土内部测试元件，对冲切破坏斜面上混凝土变形进行了量测，总结出破坏斜面上混凝土应分布及裂缝的形成和发展规律；对比了普通混凝土与浮石轻骨料混土板冲切破坏的异同；建立了半经验－半理论冲切承载力计算公式。     

Al-Sn-Ga-Bi-Pb-Cd合金电极低温海水电化学性能研究

制备了一种Al-Sn-Ga-Bi-Pb-Cd新型铝合金阳极,研究铝阳极在常温及低温海水中的电化学性能和腐蚀形貌。结果表明:低温海水环境使铝阳极开路电位正移,20℃时开路电位约在-1.23 V(vs.SCE),4℃海水中开路电位偏移至-0.91 V。低温海水环境使电荷转移电阻(Rt)增大,减弱了合金的活化能力,20℃下Rt为1.56 m~2,4℃时增大到3.39 m~2。恒电流放电实验显示,20℃海水中阳极激活时间为5 min,稳定电位达到-1.31 V,而4℃时激活时间为30 min,稳定电位为-1.15 V。铝阳极溶解为局部腐蚀,电流密度在3 A/dm~2使铝阳极溶解更为均匀,溶解过程有部分金属发生脱落,腐蚀产物主要为氢氧化铝以及少量镁钙的氢氧化物。     

Reverse flotation separation on diaspore and kaolinite in the presence of cationic polyacrylamide polymers

1　INTRODUCTIONChinaisrichindiasporebauxiteresources[1,2 ]whichpossessspecialpropertiessuchashighgradeofbothAl2 O3andSiO2 andlowFecontent,buttheAl/Si(massratioofAl2 O3toSiO2 )valueislow .Inordertotreatthediasporebauxite ,unitedmethodsandsin teringmethods[3] arestillappliedalthoughsufferingfromdisadvantagesincludingcomplextechnologyflowchart,highenergyconsumption ,highproduc tioncost ,andrestrainingfurtherdevelopmentofalu minaindustry .However ,byimprovingbauxiteAl/Si>10 ,wecanchoosem…