无机盐杂质对铝酸钠溶液晶种分解率的影响

采用对比实验法, 研究了不同类型、不同浓度的无机盐杂质对铝酸钠溶液晶种分解的影响, 并探讨了其影响机理。结果表明, 铝酸钠溶液中氯化钠、碳酸钠、硫酸钠等杂质的存在对晶种分解会产生不利影响, 当NaCl浓度大于10 g/L、Na₂O_s浓度大于5 g/L、Na₂O_c浓度大于10 g/L时, 均将对铝酸钠溶液晶种分解产生明显的抑制作用。无机盐杂质的存在会影响铝酸钠溶液中氢氧化铝颗粒表面的Zeta电位值, 使Zeta电位变得更负, 不利于氢氧化铝晶体颗粒对铝酸根离子的吸附, 从而对铝酸钠溶液晶种分解产生抑制作用。无机盐杂质使铝酸钠溶液表面张力增大, 也阻碍铝酸根离子在晶体表面的吸附, 对晶种分解产生不利影响。     

“轻金属冶金学”课程多位教师联合教学的实践

轻金属冶金学是冶金工程有色金属冶金专业的骨干专业课程,是以培养具有宽厚基础理论知识和较强实践能力的有色轻金属冶金方面的高级专门技术人才为目标,采用多教师联合教学模式取得了可喜的成绩,能在真正意义上促进该目标的实现。在介绍轻金属冶金学专业课程的特点、多教师联合教学模式的优点及其具体教学实践的同时对实践过程中存在的问题进行了深入反思,并提出了相应的解决办法。轻金属冶金学课程由多位教师联合教学的实践可为具有类似特点的冶金工程其他专业课程或其他工程类专业课程的本科教学改革提供参考。     

在科技活动中培养大学生的创新精神和研究工作能力

分析了多年来大学教育只重视基本知识、基本技能的传授,忽略创新精神和研究工作能力培养的不足,强调在大学生中开展科技创新活动的重要性,介绍了黑龙江工程学院测绘工程系在开展大学生科技活动。培养大学生创新精神和科研工作初步能力方面的尝试和体会。     

2250 t/h绳索牵引补偿小车式抓斗卸船机

大连大起集团向宝钢马迹山港提供的2250t／h抓斗卸船机为绳索牵引式补偿小车机型，是在引进吸收先进技术与多年生产经验的基础上设计、制造的又一大型卸船设备，交付使用2年多，技术性能稳定，满足各项设计指标。     

Intensifying digestion of diaspore and separation of alumina and silica

1　INTRODUCTIONDespitetheabundantdepositofbauxitesinChi na ,ofthosepredominantisthediasporictypewithhighalumina ,highsilicaandlowferricoxides .Thebauxitedeposit,withthemassratioofaluminatosil ica(A/S)between 4and 8,accountsfor 80 %ofallthebauxitedeposit.Thenatureofhighsilicacontentdeterminesthatthemainlyadoptedtechniquetopro ducealuminainChinashouldbeBayer sinteringcom binationprocessorevenpuresinteringprocess .Althoughadramaticadvancementinaluminaproductionhasbeenachievedandthetechnolo…     

Temperature dependence of crystal structure and digestibility of roasted diaspore

Through X-ray diffraction patterns and scanning electronic micrographs, temperature dependence of the crystal structure of roasted diasporic bauxite at different temperatures and the digestibility of roasting production were investigated systematically. The lattice parameters of unit cell for chemically purified diaspore and unequilibrium alumina-contained oxide obtained from the diaspore roasted at different temperatures were determined. It is found that, with roasting temperature increasing, the roasting production changes from the original dense and perfect diaspore crystal into imperfect corundum with many microcracks and small pores on its surface and then into perfect corundum with low digestibility. The optimum roasting temperature with best digestibility is approximately 525℃ when residence time is about 25min. It is thought that the change of crystal structure, formation of microcracks and small pores in the temperature field are the main essential reasons for improving digestibility of diasporic bauxite and its roasting production.     

Behavior of calcium silicate hydrate in aluminate solution

Using calcium hydroxide and sodium silicate as starting materials, two kinds of calcium silicate hydrates, CaO · SiO2 · H2O and 2CaO · SiO2 · 1.17H2O, were hydro-thermally synthesized at 120 ℃. The reaction rule of calcium silicate hydrate in aluminate solution was investigated. The result shows that CaO · SiO2 · H2O is more stable than 2CaO · SiO2 · 1.17H2 O in aluminate solution and its stability increases with the increase of reaction temperature but decreases with the increase of caustic concentration. The reaction between calcium silicate hydrate and aluminate solution is mainly through two routes. In the first case, Al replaces partial Si in calcium silicate hydrate, meanwhile 3CaO · Al2 O3 · xSiO2 · (6-2x) H2 O (hydro-garnet) is formed and some SiO2 enters the solution. In the second case, calcium silicate hydrate can react directly with aluminate solution, forming hydro-garnet and Na2O · Al2O3 · 2SiO2 · nH2O (DSP). The desilication reaction of aluminate solution containing silicate could contribute partially to forming DSP.     

坚持特色发展战略 构建应用型工程技术人才培养新模式

回顾黑龙江工程学院测绘工程专业的办学历史,分析在高等教育大众化的背景下坚持特色办学的意义,论述构建应用型工程技术人才培养模式的基本思想和人才特征,设计了人才培养新模式的实践教学环节,并在测绘工程专业应用型人才培养中得到了应用。     

氢氧化铝脱水过程的动力学研究

根据变温DSC-TGA曲线,运用Coats-Redfern方程,对某拜耳法氧化铝厂工业种分氢氧化铝的脱水过程进行动力学研究。结果表明,在温度段268.08℃~308.21℃和473.14℃~548.51℃,氢氧化铝的脱水动力学反应机理分别为三维扩散和化学反应,其表观反应速率常数分别为0.0353 s-1和0.0913 s-1,反应活化能分别为817.13kJ/mol和501.47kJ/mol。     

共沸蒸馏制备超细氧化铝粉

采用共沸蒸馏工艺成功地制备了超细氧化铝粉,通过共沸蒸馏能有效地消除粉末的硬团聚。本文还系统地分析了粉末硬团聚形成的机理,从而制得了粒径d_(50)为0.47μm的超细氧化铝粉。