氧化铝水合物酸溶性的研究

本文对市售的工业氢氧化铝、细氢氧化铝、拟薄水铝石及凝胶氢氧化铝进行了酸溶性对比实验。XRA、DTA及粒度分析数据表明,氧化铝水合物的酸溶性,主要取决于晶形,其次是晶化程度。     

碳分母液二次碳分产物的应用途径

简要说明了碳分母液二次碳分回收粗氢氧化铝的意义,主要研究了粗氢氧化铝的酸溶解试验、制备高、低αK偏铝酸钠试验、拜耳法精液添加试验、4A沸石母液溶解试验、一次脱硅过程添加试验,讨论了粗氢氧化铝的应用途径。     

SH—M75氢氧化铝新产品的开发与生产

简介了SH－M75氢氧化铝的用途及中州铝厂开发生产非冶金级氢氧化铝的优势。根据SH－M75氢氧化铝生产方法的开发情况,确定了以连续碳分工艺和闪蒸干燥技术进行生产。在生产中通过采取各种措施,控制了产品的许多关键指标,产品性能良好,供不应求。     

黄药浮选氧化铜矿物时螯合剂的协同活化作用

螯合剂初步疏水性活化作用包括对矿物表面活化和对黄药吸附性能的活化，并且活化作用与药剂的化学活性和矿物的溶解特性有关。这类螯合剂更适合于活化孔雀石型或主要由易溶性铜矿物组成的矿石。     

种分法制备超细氢氧化铝过程中的粒度控制

超细氢氧化铝具有许多优点,应用广泛。超细氢氧化铝的粒度分布和颗粒形貌对产品的性能有很大影响。根据湿化学法颗粒成核与生长机理从理论上分析了超细氢氧化铝制备过程中需控制的工艺条件,研究了二段分解工艺中晶种添加量和温度等对分解产品粒度分布的影响,得出了温度和种子添加量对氢氧化铝粒度分布的影响规律。     

氢氧化铝在苛性碱中溶解动力学研究

实验研究了氢氧化铝在苛性碱中溶解的表现动力学方程,在氢氧化铝溶解过程中存在着一对可逆过程,最终建立两相平衡体系.从动力学方程推测了氢氧化铝在苛性碱中溶解的机理,在溶解过程中没有发生化学反应.仅是氢氧化铝晶体的氢键断裂.氧化铝在苛性碱溶液中以Al(OH)3单分子形态存在.在溶解结束或者种分过程结束时,在苛性碱溶液中,液相中的Al(OH)3与固相通过氢键的生成或断裂构成的两相吸附平衡.实验得到了在平衡状态下,液相中氧化铝的平衡浓度与苛性碱浓度、温度以及固相量的关系,与经验公式数值吻合较好.     

冰晶石的生产方法

直到目前为止所采用的生产方法都是从氟原料一氟石中生产冰晶石。按此法首先生产氟酸,然后再用一般的方法从氟酸中制取冰晶石。所采用的氟石在纯度上有特殊的要求,所以它的价格是相当高的。其次,还有一种方法,即是使氟硅酸钠在加入高温水的情况下与氧化铝或氢氧化铝反应成冰晶石和胶态溶解硅酸。     

高白度氢氧化铝中疵点的来源及控制方法

通过分析疵点对高白度氢氧化铝质量的影响 ,查清了氢氧化铝中疵点的主要来源 ,找到了生产中有效控制高白度氢氧化铝中的疵点的方法 ,通过采取措施成功地生产出各项指标合格的高白度氢氧化铝。     

从碳分母液回收化工用碳酸铝

我厂烧结法生产氧化铝，返回配料的碳分母液携带Ａｌ２Ｏ３量高达７万吨／年，实际作用仅限于替代铝矿石配制生料。以市场需求为导向，追踪技术发展动态，开发出碳分母液生产化工用含ＣＯ２的氢氧化铝（国外称碳酸铝）。该品平均含Ａｌ２Ｏ３５８．９％、ＣＯ２２．９４％、Ｎａ２Ｏ３．１１％、ＳｉＯ２０．６４％，所含ＣＯ２遇酸逸出，将Ａｌ（ＯＨ）３颗粒崩裂细化，使酸溶性为工业氢氧化铝的３－５倍。鉴于ＳｉＯ２不溶于酸，故     

从碳分母液中回收化工用碳酸铝

山东铝厂烧结法生产氧化铝，返回配料的碳分母液携带Ａｌ２Ｏ３量高达７万吨／年，实际作用仅限于替代铝矿石配制生料。以市场需求为导向，追踪技术发展动态，开发出碳分母液生产化工用含ＣＯ２的氢氧化铝（国外称碳酸铝）。该品平均含Ａｌ２Ｏ３５８．９％、ＣＯ２２．９４％、Ｎａ２Ｏ３．１１％、ＳｉＯ２０．６４％，所含ＣＯ２遇酸逸出，将Ａｌ（ＯＨ）３颗粒崩裂细化，使酸溶性为工业氢氧化铝的３－５倍。鉴于ＳｉＯ２不溶于酸     

超细氢氧化铝筛上物形成原因及解决措施

根据影响氢氧化铝粒度大小的因素,得到筛上物主要来自原料中的杂质以及分解过程产生的大颗粒的结论。对超细氢氧化铝的生产条件进行了详细分析,通过降低自分解影响、保证种子浆活性、保证分解最佳温度以及清洗分解槽等一系列措施来减少超细氢氧化铝筛上物的形成。     

拜耳法赤泥凝胶法制备防腐颜料三聚磷酸铝

本文以拜耳法赤泥和工业磷酸为主要原料,用盐酸溶出拜耳法赤泥中的铝,来制备三聚磷酸铝。在制备工艺中,分别对拜耳法赤泥中铝的溶出和三聚磷酸铝的制备等相关参数进行了系统研究,得到了拜耳法赤泥制备三聚磷酸铝的最佳工艺参数。对产品进行测试分析,研究表明,按最佳工艺参数生产的三聚磷酸铝产品具有很好的防腐性能,且达到工业指标,并与工业氢氧化铝合成工艺进行比较表明,凝胶氢氧化铝合成工艺可以降低能耗、缩短周期。因此,该工艺具有非常好的环保意义和应用前景。     

Untersuchungen zur Morphologie von Aluminiumhydroxiden und anodischen Aluminiumoxiden mit dem Rasterelektronenmikroskop

Investigations on the morphology of aluminium hydroxides and anodic aluminium oxide films using scanning electron microscope Hydroxide films of spongy structure are originated on aluminium surfaces if aluminium is trated with hot water for short periods. By increasing the reaction time the hydroxide layers start to become more compact until films are growing coherent showing a porous surface. If the reaction time exceeds 4 hours at a reaction temperature of 98°C crystalline scales appear on the top of the films. During the anodic oxydation of hydroxide coated aluminium in citric acid solutions, thin hydroxide films transform into barrier layer type oxides. If the anodization occurs in aggressive electrolytes the existing hydroxide dissolves and oxide layers with porous structure are obtained. Oxide layers produced by anodizing in hot citric acid solutions in the absence of a hydroxide film show a current density dependent morphology. At higher current densities barrier layer type oxides are growing. Using low current densities oxide layers with a character are predominating.     

Korrosionsinhibierung bzw. -stimulation von Aluminiumpigmenten im alkalisch wäßrigen Medium durch Polyacrylsäuren

Corrosion inhibition resp. stimulation of aluminium pigments in aqueous alkaline medium by polyacrylic acids Flakelike aluminium pigments (aluminium content > 99.5%) are corroded in a mixture of water and butyl glycol at pH = 10 by the evolution of hydrogen. Low-molecular weight polyacrylic acids inhibit the corrosion of aluminium pigments with addition of 0.3–0.5 weight-% significantly better than high-molecular weight polyacrylic acids. By addition of very low amounts (0.05–0.1 weight-%) of polyacrylic acid the low-molecular ones show no effect whereas high-molecular polyacrylic acids stimulate the corrosion reaction. That means that high-molecular weight polyacrylic acids show a contrary action depending on their concentration. The measurement of dissolved aluminium(III) by atomic absorption spectroscopy indicates the formation of (at least partial) soluble aluminium(III)-polyacrylate-complexes whereby the solubility with addition of low-molecular weight polyacrylic acids is lower than with high-molecular.     

沙漠浮土中可溶性盐对铝的大气腐蚀影响

通过干湿循环加速试验模拟Al表面沉积沙漠浮土情况下的大气腐蚀过程,利用失重分析、扫描电镜（SEM）和大气腐蚀监测仪（ACM）研究浮土中可溶性盐对Al的大气腐蚀的影响。结果表明：浮土中的可溶性盐会使发生大气腐蚀的相对湿度范围变宽,随着可溶性盐含量的提高,Al的腐蚀不断恶化。在可溶性盐成分中,MgCl₂对Al的腐蚀影响最大,NaCl次之, MgSO₄和Na₂SO₄的影响较小。     

气体硬化水溶性砂芯的性能研究

以电熔刚玉为骨料、氢氧化钡为粘结剂、铝粉为添加剂的型芯混合料在吹入CO_2气体后即可实现硬化。本文研究了这种型芯的硬化工艺和常温特性,并采用X射线衍射分析、失重—示差热分析等方法,结合粘结膜的扫描电镜照片,对型芯的受热物理化学变化、高温强度、水溶性等行为进行了实验研究。     

Effect of some nitrogen containing organic compounds on the corrosion and polarization behaviour of aluminium in 1M solutions of sodium hydroxide and hydrochloric acid with and without calcium

The effects of some organic compounds namely formamide, pyridine, gramine, dipyridyl, piperidine, benzoyl piperidine and dibenzyl disulphide on the corrosion of 2S aluminium in 1M sodium hydroxide and 1M hydrochloric acid have been investigated. All the compounds are not effective as inhibitors by themselves in sodium hydroxide solution but their conjoint action with calcium enhances their inhibition efficiency to a great extent. In 1M hydrochloric acid their inhibition efficiency is high and calcium, contrary to its behaviour in sodium hydroxide, does not possess any beneficial effect on the influence of these compounds. The polarization behaviour of aluminium in the acidic and the alkaline solutions in the presence of these compounds is discussed.     

Einfluß des pH-Wertes auf die Korrosionsinhibierung von Aluminiumpigmenten durch Styrol-Maleinsäure-Copolymere

Effect of pH on the corrosion inhibition of aluminium pigments by styrene-maleic acid copolymers Aluminium pigments corrode in a mixture of water and butyl glycol in the ratio 9:1 with the evolution of hydrogen. The aluminium pigment without corrosion inhibitors reacts at pH 10 faster than at pH 8. Styrene-maleic acid copolymers inhibit this corrosion reaction; the corrosion inhibiting effect increases with decreasing acid number of the copolymers. With addition of low-molecular styrene-maleic acid copolymers (relative molar mass ≤ 60000) less hydrogen is evolved at pH 8 than at pH 10; the solubility of aluminium(III) in the corrosion medium is at pH 8 lower than at pH 10. With addition of high-molecular styrene-maleic acid copolymers (relative molar mass ≥ 100000) it is just the other way round: At pH 8 more hydrogen is evolved than at pH 10; the solubility of aluminium(III) in the corrosion medium is at pH 8 higher than at pH 10.     

Buffering effects on electrograining of aluminium in nitric acid

Electrograining of a binary Al-Si alloy has been undertaken in nitric acid based electrolytes, with the resultant surfaces examined by scanning and transmission electron microscopies. Depending on electrograining conditions, the pit appearance varies from hemispherical to large lateral pits, with the latter favoured in relatively acidic electrolytes. The conditions prevailing in the pit have been explored through use of aluminium ion additions to the nitric acid electrolyte as well as additions of species which influence the precipitation and dissolution of aluminium hydroxide. These confirm that control of the pit solution pH, through hydroxide generation, as a result of the selected electrograining conditions and consequent anodic and cathodic polarisation, enables tailoring of the resultant electrograined surface appearance.