拜耳法生产氧化铝的分解工艺

种子分解是拜耳法生产砂状氧化铝工艺中一个十分重要的生产单元,它直接影响氧化铝产品的质量.目前国内外生产砂状氧化铝的种子分解工艺共分为一段分解工艺和二段分解工艺.本文根据我国一水硬铝石生产砂状氧化铝的实际情况对一段分解及二段分解进行介绍并完成技术经济评估工作.     

黄磷电炉电尘灰中镓的提取可能性

通过对黄磷生产过程中矿渣灰的定量分析,提出了从电尘灰回收稀散元素镓的建议。综述了目前国内外各种提取方法的优缺点,提出了电炉法生产黄磷电尘灰中镓的提取方法。     

粉煤灰中镓富集与浸出工艺研究

为从粉煤灰中提取金属镓,首先对粉煤灰进行浮选,然后在微波条件下对浮选富集后的粉煤灰进行酸浸,讨论了捕收剂种类、微波时间、盐酸浓度、反应温度和液固比对镓浸出率的影响。通过单因素实验确定优化的粉煤灰中镓富集与浸出工艺条件为:选择十八胺为捕收剂、微波时间15min、盐酸浓度10%、反应温度70℃、液固比5∶1,在此条件下,镓浸出率为84.21%,比常规酸浸法提高了10.13%。     

Preferential extraction of gallium from Bayer liquor using ion exchange chelating resin containing hydroxamic acid functional group

Gallium extraction studies were carried out using resin containing an hydroxamic acid functional group. Extraction was dependant on reaction time and alkali concentration. The resin did not extract aluminium. Vanadium extraction kinetics were slower than those of gallium. The gallium and vanadium separation efficiency increased with decreasing contact time with extractions of 64% and 32% respectively after 1 min. Gallium extraction was independent of alkali concentration up to 250 g dm^?3 and thereafter decreased with increasing alkali concentration. Vanadium extraction decreased with increasing alkali concentration. Cyclic batch and column studies were carried out with synthetic as well as actual Bayer liquor to test the stability and preferential extraction of gallium using the resin. It was observed that using resin partially loaded with gallium, the co‐extraction of vanadium could be minimised. Copyright © 2003 Society of Chemical Industry     

拜耳法中石灰添加量对氧化铝溶出率的影响

在拜耳法高压溶出过程中，添加石灰可以改善氧化铝溶出的工艺过程，石灰添加量对氧化铝溶出率影响极大；最佳的石灰添加量可以获得较好的溶出效果。     

Separation of Gallium and Aluminum from HCl Solution by Microemulsion

Gallium was separated from aluminum in hydrochloric acid medium by a steady microemulsion. In the cetyltrimethylammonium bromide (CTAB)/n-pentanol/n-heptane/HCl/tributyl phosphate (TBP) system, TBP was introduced as the modifier to avoid emulsification of the microemulsion. The extraction efficiency on gallium was also improved by adding TBP. The factors that influenced the separation efficiency were explored. The results of the experiments showed that the gallium and aluminum were effectively separated within a very short time, and the extraction efficiencies of gallium and aluminum were 92% and 5%, respectively. The maximum back-extraction efficiency of gallium was 92% in HCl solution (4 M).     

Synthesis of Gallium Oxide Hydroxide Crystals in Aqueous Solutions with or without Urea and Their Calcination Behavior

Gallium oxide hydroxide (GaOOH· x H₂O) single crystals were synthesized in aqueous solutions by using two different precipitation techniques: homogeneous decomposition of urea and forced hydrolysis in pure water. Precipitation of crystals started at exactly the same pH value (i.e., 2.05 at 85°C) in both cases. The morphology of crystals turned out to be quite different (zeppelin-like with urea, rodlike without urea) in each of the above methods. Calcination of these gallium oxide hydroxide crystals in air at temperatures ≥500°C transformed them into Ga₂O₃. Characterization of the samples was performed by X-ray diffractometry, scanning electron microscopy, thermogravimetry/differential thermal analysis, Fourier transform infrared spectroscopy, and ICP, carbon, and nitrogen analyses.     

吹风气回收装置积灰问题分析与处理

通过对吹风气回收装置增加吹风气的集中除尘器、增加余热锅炉系统的吹灰器及进行必要的工艺调整,解决了装置因积灰导致的换热效率低、蒸发量低、热损失大的问题,使装置基本达产、达效。     

铜渣氯化烟尘中铜的湿法回收

采用盐酸搅拌浸出-N902萃取工艺回收铜渣氯化烟尘中的铜,考察了影响铜渣氯化烟尘浸出的主要因素. 结果表明,在盐酸浓度15%(w)、液固比4 mL/g、60℃的条件下浸出1 h,铜浸出率可达98.95%,铁、锌、镍浸出率分别达91.58%, 95.8%和93.66%,铅浸出率为5.96%. 盐酸浸出可实现铜与铅的有效分离. 萃取剂N902对浸出液中的铜具有较好的萃取选择性,振荡时间120 s、相比为1、N902浓度30%和pH=3.0的条件下,浸出液铜浓度由7.4 g/L降至0.11 g/L,回收率达98.51%,浸出液中Fe, Zn, Ni和Pb萃取率均不高于1.5%.     

三明炼钢粉尘的基本物性及酸浸回收锌的实验研究

采用化学分析、XRD、湿式筛分、显微镜观察、SEM-EDS等方法系统研究了三明炼钢粉尘的元素组成、粒度分布、物相、表面形貌及元素分布等基本物性;并进行其酸性浸出条件实验,考察了初始酸浓度、MnO2加入量、温度、浸出时间等因素对矿浆终点pH值、过滤性能及Zn, Fe, SiO2浸出率的影响. 结果表明,在25℃、初始酸浓度26.6 g/L、加MnO2 0.4 g、浸出120 min后,矿浆pH=3.5~3.7,粉尘中Zn的浸出率达98%,而Fe和SiO2浸出率分别为0.22%和9%,且矿浆的过滤性能良好.     

磷铵干燥尾气湿法除尘系统工艺改进及应用

简介磷铵干燥尾气湿法除尘系统工艺改进,及其在实践中应用效果创造的经济效益。     

大孔偕胺肟树脂的合成及其对镓的吸附性能

采用悬浮聚合法先合成出了丙烯腈(AN)-二乙烯基苯(DVB)交联骨架,制备了具有偕胺肟基团的大孔螯合树脂,表征了其结构和形貌,并用于拜耳溶液中镓的吸附. 研究了二乙烯苯含量、油相稀释剂种类及用量、第三单体、胺肟化反应条件对树脂吸附镓的性能的影响. 结果表明,螯合树脂的吸附性能随DVB含量增加先增加后降低,DVB含量为8%(w)时吸附性能最好,选用60%(w)甲苯和30%(w)航油作油相稀释剂,树脂的吸附率最大,分别为46%和52%. 添加少量(2%)第三单体甲基丙烯酸甲酯使树脂吸附率提高到57%.     

改性拜耳法赤泥两段酸溶法制备 聚合氯化铝铁研究

拜耳法赤泥是拜耳法生产氧化铝所产生的碱性废渣,含有大量未被溶出的铝、铁等金属元素,直接筑坝堆存处理既污染环境又造成资源浪费。以改性拜耳法赤泥为原料,采用两段酸溶法制备高效絮凝剂聚合氯化铝铁（PAFC）,并对制备的聚合氯化铝铁进行絮凝性能实验,结果表明絮凝效果良好。该法与传统工艺比较省去了加碱调节盐基度过程,最大程度地利用了盐酸,节约了生产成本。该研究为无机高分子絮凝剂聚合氯化铝铁的制备提供了一套新的工艺流程,为解决拜耳法赤泥筑坝堆存所造成的环境污染和资源浪费问题提供了一条新途径。     

黄磷生产电尘浆中镓含量的测定——罗丹明B吸光光度法

探索了采用罗丹明B吸光光度法测定电尘浆中镓含量的条件 ,并通过精密度、回收率试验验证该方法精密度较好 ,标准偏差在 0 .0 0 11%～ 0 .0 0 15 %;准确度高 ,加标回收率在 98.8%～ 10 2 .0 %,表明该方法对电尘浆中镓含量的测定可行。     

High Fraction of Penta‐Coordinated Aluminum and Gallium in Lanthanum–Aluminum–Gallium Borates

This study is focused on structural changes induced by increasing treatment temperature of sol‐gel–derived La₂O₃?Al₂O₃?Ga₂O₃?5B₂O₃ system. The structure of samples heated for 30 min up to 900°C was investigated by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and magic‐angle spinning nuclear magnetic resonance (MAS‐NMR) analysis of ²⁷Al, ¹¹B, and ⁷¹Ga nuclei. The vitreous structure is preserved inclusively after 800°C treatment, and starting with 850°C the only crystalline phase evidenced in XRD patterns is of LaAl_2.03B₄O_10.54 type, of La(Al,Ga)_2.03B₄O_10.54 composition. The FTIR results point out the presence of BO₃, AlO₄, and AlO₆, and starting with 800°C treatment also of BO₄ and AlO₅ structural units, but more detailed information related to boron, aluminum, and gallium environments is obtained from the analysis of MAS‐NMR data. These data evidenced in both amorphous xerogels and in crystallized samples a high fraction of penta‐coordinated aluminum and gallium.     

尿素造粒塔粉尘回收工艺的应用

介绍尿素造粒塔粉尘回收工艺流程,特点,主要设备,运行的工艺指标,产生的效益以及粉尘回收装置投运后存在的问题。     

含钙添加剂强化─水硬铝石矿拜耳法溶出过程的作用分析

一水硬铝石型铝土矿在拜耳法过程中很难溶出,加入石灰等添加剂可以改善其溶出性能．本文评述了石灰、其它含钙化合物、合成铁－水化石榴石以及ＣａＯ＋（Ｍｎ／Ｆｅ）等添加剂的作用效果,并对其作用机理进行了分析．     

ANFIS-Based Prediction of the Decomposition of Sodium Aluminate Solutions in the Bayer Process

This article presents the results of nonlinear statistical modeling of the decomposition process of sodium aluminate solution, as part of the Bayer technology for the production of alumina. Based on the data collected in 2011 and 2012 from industrial production in the Bira? Alumina Factory, Zvornik (Bosnia and Herzegovina), nonlinear statistical modeling of the industrial processes was derived. The model was developed as an attempt to define the dependence of the degree of decomposition of sodium aluminate solution as a function of the input parameters of the leaching process: caustic ratio (α_k) of the solution; ratio of the crystallization; content of Na₂O_(caustic) in the solution; the initial temperature of the solution; the final temperature of the solution; average diameter of the crystallized seeds; and duration of the crystallization process. As a tool for statistical modeling, Adaptive Network Based Fuzzy Inference System (ANFIS) was applied. The defined model using ANFIS methodology expressed a high level of fitting, and could be used to effectively predict the degree of decomposition of the sodium aluminate solution as a function of the input process under industrial conditions.     

高铝高镓煤矸石的综合利用

针对湘潭盛家山煤业有限公司云湖桥矿区高铝高镓煤矸石的综合利用,文章对云湖桥矿区废弃煤矸石的特点进行了分析,对研究目标、研究方法、技术路线、预期成果和经济效益分析进行了详细的阐述.     

含铟氧化锌烟尘加压硫酸浸出工艺优化

对含铟氧化锌烟尘加压浸出进行正交实验及单因素实验,考察各因素对浸出的影响. 结果表明,各因素对铟浸出率的影响显著程度为初始硫酸浓度>液固比>压力>温度>时间,对锌浸出率为初始硫酸浓度>液固比>温度>时间>压力. 优化工艺条件为温度140℃,釜内压力0.6 MPa,时间90 min,液固比8 mL/g,初始硫酸浓度160 g/L,搅拌速率500 r/min. 该条件下锌和铟浸出率分别达99%和91%以上,锌与铟可同时高效浸出,浸出液残酸低,工艺稳定性好