改性油页岩吸附水中苯酚的研究

研究了不同条件改性后油页岩对苯酚的吸附能力,讨论了改性油页岩对苯酚的吸附动力学和Freundlich等温吸附方程.结果表明,经950℃热解2h、10%NaOH溶液改性及500℃热解4h、65%HNO3溶液改性的两种油页岩对苯酚具有很好的吸附能力,且前者的吸附能力远大于后者,前者的吸附方式主要为化学吸附,后者主要为物理吸附.     

油页岩灰陶粒吸附苯酚的实验研究

以油页岩灰为主要原料,通过烧结法制备陶粒,用其作为吸附剂,使油页岩资源得到综合利用.通过吸附苯酚实验,确定了陶粒中油页岩灰的最佳含量为90%,最佳烧结温度为1 150 ℃;苯酚的吸附率随着陶粒用量的增加而增大,对25.0 mL 0.1g/L的苯酚溶液,陶粒用量为2.0 g时,具有较好的吸附率;随着吸附时间的增加,苯酚的吸附率也逐渐增加,150 min达到吸附平衡;当苯酚初始质量浓度大于0.1 g/L时,陶粒对苯酚的吸附率达到70%左右,具有较好的应用价值.     

Study on non-saponification extraction process for rare earth separation

The purpose of this study was to overcome the disadvantages of ammonia-nitrogen wastewater pollution and high cost of sodium saponification in rare earth separation process. The study focused on the non-saponification extraction technology with magnesia. The influences of the content and particle size of magnesia, reaction time, reaction temperature, and O/A on cerium extraction rate were also discussed. The results showed that the hydrogen ions of extractant were exchanged by rare earth ions when organic extractant and rare earth solution were mixed with magnesia powder, and then the exchanged hydrogen dissolved magnesia to make the acidity of the system stable. The magnesium ions were not participated in the extraction reaction. Non-saponification extraction process of rare earth had been realized. The cerium extraction rate could reach up to 99% in single stage within the optimal reaction conditions.     

Study on preparation and application of novel saponification agent for organic phase of rare earths extraction

In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the natural rich and cheap dolomite as raw material through carbonation process. The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched. The results showed that the concentration of Fe, Al, Si impurities ions was less than 5 ppm in the saponification agent through the development of effective removal technology, respectively. When the novel saponification agent was used in the extraction and separation, magnesium utilization rate was more than 95%, and rare earths extraction rate above 99.5% has achieved. Therefore, the technology could replace ammonia-water to saponify the organic phase in rare earth extraction and separation process.     

Effect of impurity ions on preparation of novel saponifier for rare earth extraction

Magnesium bicarbonate,prepared by the carbonation of magnesium hydroxide slurry,was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process.The effect of impurity ions introduced by system on the carbonation reaction of magnesium hydroxide was studied in the work.The results showed that the presence of Ca2+ could lead to side reactions so as to reduce the conversion rate of magnesium hydroxide,and a small number of rare earth ions would have great influence on the carbonation reaction.What’s more,there was no influence on carbonation reaction with the low concentration of Na+or Mg2+,the conversion rate of magnesium hydroxide could reach above 96%.This paper showed a practical theory which could provide scientific guidance for the preparation of novel saponifier in rare earth extraction separation process.     

白云鄂博混合型稀土精矿在惰性气氛下的热分解行为（英文）

为了开发和应用白云鄂博混合型稀土精矿的先进冶炼技术,采用Kissinger公式、TGA-DSC和XRD等分析方法,研究在氮气氛下白云鄂博混合型稀土精矿的热分解行为,包括热分解动力学、物相变化规律、铈氧化效率以及物相变化对稀土浸出率的影响。结果表明：在500～550℃焙烧时,焙烧质量损失率约10%、热分解活化能(E_a)为148 k J/mol。550℃焙烧2 h,白云鄂博混合型稀土精矿中氟碳铈矿完全分解,并转化为稀土氧化物和氟氧化物,铈氧化率最大值为0.58%。600℃焙烧2 h,稀土最大浸出率达49.1%。     

稀土萃取分离废水制备氢氧化镁工艺研究

以白云石和稀土萃取分离过程中产生的氯化镁废水为原料制备氢氧化镁,为解决所得氢氧化镁料浆难过滤的问题,考察了温度、加料方式、加料速度、添加晶种、添加硫酸根以及直接碱转等工艺条件对料浆沉降过滤性能的影响。结果表明,与其它几种方式相比,采用轻烧白云石粉料加入氯化镁废水中的直接碱转方式,可以实现氢氧化镁料浆的快速沉降和过滤,并制备得到质量符合行业标准的氢氧化镁产品,利用XRD、SEM对其进行了表征。该工艺实现了氯化镁废水和白云石资源的综合利用。     

ICP-AES法测定稀土萃余液中HEH(EHP)含量

目前90%以上的稀土均采用溶剂萃取的方式进行冶炼分离,其中常用的萃取剂为HEH(EHP)。由于萃余液中萃取剂HEH(EHP)含量较低,无法直接检测其含量。采用硝酸和高氯酸高温分解的方法,将酸性磷类萃取剂HEH(EHP)中的磷全部转化为正磷酸盐,用电感耦合等离子发射光谱法(ICP-AES)测定样品中的磷含量,从而通过测量磷含量推断得到萃余液中萃取剂含量,建立了一种简单快捷高效的处理和测试样品的方法。试验结果表明,最佳的分析谱线波长为213.618 nm,该方法测试检出限达到0.06 mg·L~(-1),磷加标回收率达到97.5%～103.0%,同时样品的测试标准偏差控制在5%以内。通过对提纯后的HEH(EHP)进行称重消解测试分析发现,采用硝酸和高氯酸混合分解的方法可以将有机磷完全转化为正磷酸盐,从而验证了本方法的可行性。此方法将大大提高萃余液中萃取剂含量的分析速度和测量精度,为稀土冶炼分离过程中萃余液中萃取剂含量的分析检测提供了技术保障。     

离子吸附型稀土矿硫酸镁浸取尾矿中钙、镁的淋出行为

研究采用去离子水、氯化钙溶液、石灰水淋洗剂淋洗,离子吸附型稀土矿硫酸镁浸取尾矿中镁、钙的淋出行为。结果表明,浸取尾矿中的镁主要以水溶态形式存在,这部分镁易被淋洗脱除。采用石灰水淋洗,淋洗剂中的绝大部分钙可被静电吸附在淋洗后尾矿中,同时浸取尾矿中的部分水溶态镁因Mg2+在黏土矿物上的反吸附作用而逐渐转化为交换态镁,这与淋洗后尾矿pH值的升高有关。采用石灰水淋洗,当液固比为0.80时,淋洗后尾矿中速效镁、钙含量分别为104.4~207.6和201.7~1426.3 mg/kg,满足植物的生长需求。该研究为离子吸附型稀土矿原地浸矿场的环境修复提供一种有潜力的解决方案。     

硫酸镁溶液高效制备碳酸氢镁及皂化萃取分离稀土（英文）

为实现包头混合型稀土精矿冶炼分离过程中硫酸镁废水的循环利用,开展硫酸镁溶液碱转制备氢氧化镁、CO₂碳化制备碳酸氢镁溶液,以及硫酸稀土溶液的皂化HDEHP萃取分离转型技术研究。研究碳酸氢镁制备过程关键影响因素及碳化机理,以及碳酸氢镁皂化萃取过程中稀土、钙、镁元素的分布规律。结果表明,碳化过程中硫酸钙会抑制碳酸氢镁的转化,而提高硫酸镁浓度和降低碳化温度均会促进碳酸氢镁的转化。在优化的工艺条件下,实现碳酸氢镁溶液的稳定、高效制备,碳酸氢镁转化率大于95%,Fe、Al、Si等杂质含量低于15 mg/L;硫酸稀土溶液经过多级串级萃取,稀土萃取回收率大于99.5%,未出现硫酸钙结晶析出现象,萃余水相为硫酸镁溶液,循环用于制备碳酸氢镁溶液。