氧化铝

Alcoa recently announced that its Alcoa World Alumina and Chemicals affiliate and the Government of Jamaica have signed an agreement in principle to expand the Jamalco alumina refinery in Clarendon, Jamaica, by more than 1.5 million metric tons per year.

Alcoa公司最近宣布了其分公司－世界氧化铝及化学产品分厂将在牙买加的Clarendon扩充氧化铝产量的决定，该决定是和牙买加政府的合作下完成的，预计扩产后的氧化铝年产量将比原来的产量多出一倍，达到2800万吨/每年。

The main works of this paper are as follows:(1) The various methods for determining the cryolite ratio of electrolyte were summarized and compared. The phase constituents of aluminium electrolyte system were studied, the various cryolite ratio definitions for this reason were discussed.

本文研究和测定了工业铝生产中与电解质相关的几项重要的物理化学参数，包括铝电解质分子比的测定研究，氧化铝溶解性能的研究及测定，氧化铝浓度的测定及工业铝电解槽氧化铝浓度—槽电阻曲线的绘制，铝在电解质中溶解度的研究及测定。

School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）Abstract: By analyzing the crystal growth habit of gibbsite theoretically using Morphology program, the morphology character of crystal grain and the theoretic habit of gibbsite were studied.

摘 要：对氢氧化铝晶体生长习性进行Morphology理论研究，明确氢氧化铝晶粒长大后的晶粒形态特征及氢氧化铝的理论晶体生长习性。

The major products of the company are superfine particles of all levels of or surface activated powders, such as aluminum hydroxide, high temperature aluminum oxide products, and low sodium aluminum oxide.

本公司现主要产品由各级超细微粒或表面活化微粉。如氢氧化铝、高温氧化铝系列品种、低钠氧化铝。

Hydrothermal treatment and pH value swing could shift the micropore distribution of alumina to macroporous direction, and decreased surface areas; the surfactants addition could shift the micropore distribution of alumina to microporous direction, and increase surface areas.

其中pH值交替变动和水热处理使氧化铝微孔分布向大孔方向迁移，比表面降低；加入表面活性剂使氧化铝微孔分布向小孔方向迁移，比表面增加，制备出了低比表面≤150平方公尺g^(-1和高比表面≥250平方公尺g^(-1的大孔容氧化铝载体。

For more upgrade aluminium oxide yield, optimize indices, energy conservation and save cost, it is necessity to desilicify steps reconstruction.In order to overcome the shortcoming of the desilication used in Shangdong Alumina Corpotation,three technology such as indirect heating, continious desilication,deep desilication by separation of the sodium-silicon residue.

本文通过对理论界关于烧结法生产氧化铝脱硅原理的研究，结合国内主要氧化铝生产厂家脱硅实践方面的经验，针对山东铝业公司烧结法氧化铝生产脱硅工序的现状，运用间接加热连续脱硅、钠硅渣分离深度脱硅和HCAC法高效脱硅三项科研成果，对原有的三次脱硅工艺改为二次脱硅工艺。

In order to study the aldol condensation of 2.15-hexadecanedione on the surface of aluminium, the intermolecular condensation mechanism of acetone occurring on aluminum was simulated by using semi-empirical AM1 method embodied in MOPAC 6.0 program package. The optimized structures and geometry parameters of 5 transition complexes and 4 intermediates were given.First, 2 molecules of acetone coordinated with aluminum by electrostatic attraction.One atom of hydrogen of acetone migrated to aluminum because of t...

为了研究2，15－十六烷二酮在氧化铝表面的环合机理，选择小分子丙酮为模型化合物，用量子化学半经验AM1方法研究双分子丙酮在氧化铝表面的醛醇缩合机理，给出了反应过程中的5个过渡态和4个中间体的结构和几何参数，该催化反应可以认为是氧化铝分子与两分子丙酮分子发生静电络合作用，然后借助氧原子的负电荷导致脱氢并实现缩合，根据中间体的能量变化，推测有较稳定的铝复合物生成。

The results reveal that spectra obtained by different parametric methods are similar. The spectra of normal cells' voltage have only one noticeable lobe due to fluctuation of molten alumina at anodes, while spectra of other abnormal cells have one mainlobe and one sidelobe. In cells with carbon in bath the spectral mainlobe of cell voltage is still due to the fluctuation of molten alumina at anodes and the sidelobe is due to the fluctuation of carbon in bath; in cells with metal pad wave, the spectral mainlobe is due to metal pad waving and the sidelobe is still due to the fluctuation of molten alumina at anodes. Compared with wavelet packet analysis, spectral analysis is simpler and takes less time in calculation, which is a big merit in the large-scale application of online diagnosis systems of working conditions in aluminum reduction cells.

研究结果表明：不同的参数估计法得到趋于一致的频谱分析结果，正常槽只有1个尖锐谱峰，对应于阳极下熔融氧化铝涌动的特征峰，其他故障槽都有2个特征谱峰，即1个主峰和1个次峰，碳渣槽的主峰仍然对应着阳极下熔融氧化铝涌动特征峰，次峰对应悬浮碳渣的涌动特征峰；铝液波动槽主峰对应铝液波动特征峰，次峰对应着熔融氧化铝涌动的特征峰；频谱分析相对于小波包分析具有算法简单、耗时少、物理意义明确等特点，在槽况在线诊断系统的大规模推广中具有优势。

Based on the phenomena that the particles of product Al_3 have similar and big size but with poor intensity in sintering process whereas in Bayer process they have good intensity with poor particle size,this paper systematically studied the effect of carbonization seeds on precipitation of sodium aluminate solution.

结合烧结法氧化铝生产过程中存在氢氧化铝粒度均匀、粗大，但强度较差；拜耳法生产的氢氧化铝强度好，但粒度存在周期性爆发细化的问题，系统研究了碳分晶种对铝酸钠溶液分解的影响。

On the basis of the masteries for the aluminum oxide ore pulp drying and calcination, a mathematical model was developed for simulating the process of heat transfer and the calcination of two-phase flow in a new type furnace designed by Zhongzhou Branch Company, China Aluminium Corporation Limited. The fields of velocity, temperature and pressure of the two-phase flow and the reaction time were gained by optimizing calculation under the condition of different operational parameters and geometric parameters. The effect of vent position velocity and atomization particle diameter on the drying and calcination technology of aluminum oxide ore pulp was discussed.

在了解氧化铝矿浆干燥、烧成工艺及设备的基础上，针对中国铝业股份有限公司中州分公司开发的一种新的氧化铝矿浆干燥和烧成炉，建立了矿浆干燥、烧成炉内气固两相流的流动传热以及烧成过程的数学模型，就干燥、烧成炉运行参数及各几何参数进行优化计算，得出了炉内气固两相流动的速度场、温度场、压力场以及颗粒干燥和烧成反应时间，并分析讨论了喷口位置、喷口速度、颗粒雾化粒径等参数对氧化铝矿浆干燥、烧成工艺的影响。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。