阴离子交换膜渗析法回收含硫酸钠的高浓度硫酸废水

根据Fick扩散定律 ,提出了测定H2 SO4和Na2 SO4在阴离子交换膜中扩散速度的方法 .静态法测定结果显示 ,对含 2 5 0～ 3 5 0g/LH2 SO4、1 0 0～ 1 2 0g/LNa2 SO4的废水 ,常温下 ,A2 0 和 3 3 62BW膜中H 平均扩散速度分别为 8.0× 1 0 -4m/h和 7.8× 1 0 -4m/h,Na 平均扩散速度分别为 5 .9× 1 0 -5m/h和 6.6× 1 0 -5m/h,这预示两膜都能实现废酸中H2 SO4和Na2 SO4的有效分离 .动态法分离废酸结果表明 ,H2 SO4回收率达 83 .4% ,回收酸中Na2 SO4含量下降至 5 .2 g/L     

扩散渗析法回收精氨酸生产中的盐酸

为了解决精氨酸生产过程中的无机酸回收和循环再利用问题,采用阴膜扩散渗析法,针对模拟的精氨酸和盐酸混合液,在静态扩散条件下测定了盐酸的渗析系数,并考察动态扩散渗析操作参数如流速、流速比对酸回收率的影响.结果表明,采用DF-120阴离子交换膜,在静态扩散渗析中,盐酸能够顺利地透过膜,精氨酸几乎不能透过;动态扩散实验中流速、流速比对酸的回收率和回收酸的浓度有重要影响:随着流速的增加,盐酸的回收率逐渐降低,精氨酸的截留率基本上没有改变,均达到98.5％以上;流速为2 mL/min时,盐酸回收率最高,可达82％;水/料液流速比增大时,盐酸的回收率增大,但是过高的水/料液流速比又会使回收酸的浓度降低.经济核算表明,对于一个年产30 t精氨酸的装置,相对于中和法,膜扩散渗析法一年能节省的化学原料总费用约98万元,投资回收期为8个月.     

扩散渗析法回收硫酸稀土溶液中硫酸研究

对扩散渗析法回收硫酸稀土溶液中硫酸进行了实验研究,结果表明,料液中稀土浓度0～0．2mol／L范围内的较小变化对硫酸回收率没有明显影响;料液流量越大,即设备单位膜面积处理能力越大,硫酸回收率越低,回收液硫酸浓度及稀土截留率也越低,控制硫酸回收率在70％～80％较为合适;水料流量比越大,硫酸回收率越大,但回收液硫酸浓度及稀土截留率均降低,控制水料流量比在1左右较为合适;扩散渗析法能达到有效回收硫酸稀土溶液中硫酸的目的．     

扩散渗析法回收铝箔腐蚀废液中硝酸

采用扩散渗析法回收铝箔腐蚀废液中的硝酸,主要考察流量、废液中硝酸铝浓度和硝酸浓度等因素对回收酸浓度、酸回收率以及铝离子截留率的影响.结果表明:回收酸浓度和酸回收率随着流量的增大而减小,随着废液中硝酸铝浓度的增大而增大;废液中硝酸浓度对回收酸浓度、酸回收率以及铝离子截留率的影响不大.综合本文的实验结果,酸回收率最高为84.90%,此时,流量为0.24L/h(流量比为1∶1)、废液中硝酸浓度为1.30mol/L、硝酸铝浓度为0.49mol/L.     

扩散渗析法回收湿法炼铜厂电解贫液中的硫酸

采用扩散渗析法回收福建某湿法炼铜厂电解贫液中的硫酸.电解贫液经"砂滤保安过滤扩散渗析"处理,回收酸返回"萃取电积"工段,残液送至堆浸循环使用.投产一年半来,已累计回收硫酸3 929.29t,充分回收利用资源,实现循环经济,创造明显的经济效益,解决了该厂电解贫液的开路难题.     

高浓度硝酸溶液的扩散渗析过程研究

采用耐酸性良好的离子交换膜,研究含金属离子高浓度硝酸溶液的扩散渗析过程,用于回收水溶液中的硝酸.分别考察了进料液流量、硝酸浓度、酸水流量比等操作条件对非稳态扩散渗析过程的酸回收率和金属离子截留率的影响.结果 表明,硝酸的回收率随进料液流量的增大先提高后下降,随原料液中硝酸浓度的增大而下降,随酸水流量比的增大而增加.当进...     

渗析法处理氨基酸—盐酸混合液的实验研究

用盐酸溶液在不同渗析条件下考察了聚砜型阴离子交换膜的静态和动态行为．用渗析法处理氨基酸和盐酸的混合液，取得了较为满意的效果．     

扩散渗析回收含铜退镀液中的硝酸

采用扩散渗析法回收含铜退镀液中的HNO3,考察流量、流量比、温度等因素对硝酸的回收率、回收液中硝酸浓度以及铜和镍离子截留率的影响.将单级扩散渗析仪改装成新的三级扩散渗析仪,考察了三级逆流扩散渗析对实验结果的影响.单级扩散渗析的结果表明,最佳条件:水/料的流比为1∶1、流量90 mL/h、温度19℃,其硝酸回收率为86.95％、回收浓度6.04 mol/L、Cu2+和Ni2+的截留率分别为90.19％、92.71％.相对于单级扩散渗析,自行改装的三级扩散渗析过程能达到更高回收酸浓度和单位时间内处理更多的料液.在含铜退镀液体系下,利用国产扩散膜实现了扩散渗析对于H+和金属离子具有良好的分离,同时达到了回收硝酸浓度高于原退镀液的效果.     

废退锡液中硝酸和锡的综合回收

通过考察铁盐、铜盐和亚锡盐对硝酸扩散系数的影响研究了采用扩散渗析法从废退锡液中回收硝酸的可行性,实际样品的研究表明,扩散渗析法回收硝酸的回收率在70％以上．余液利用离子膜-电沉积法回收其中的金属锡,最佳工艺条件为:温度30-40℃、槽电压3．5 V、电流密度1．0-2．3 A／dm2,并保持阳极液搅拌,此时锡的回收率达62％,电流效率在60％以上．结果表明,扩散渗析-离子膜-电沉积组合工艺可有效回收硝酸型废退锡液中的硝酸和锡,以实现其资源化利用．     

酸洗废液和镀锌废渣制备锰锌铁氧体粉体的试验研究

以某钢铁厂的酸洗废液和镀锌废渣为原料,采用化学共沉淀法制备锰锌铁氧体粉体,研究反应温度对粉体收率和粒度的影响,探讨该工艺进行工业化试验的可行性,并对反应产物进行结构、形貌和磁性能分析。结果表明,制备的尖晶石型锰锌铁氧体粉末结晶性能良好,分散性好,粒径范围为1²μm;粉体性能指标符合国家电子行业标准SJ/T 1766—1997中低磁通密度下闭路铁芯制备范围的CL9F、CL10F料粉要求;考虑到工业化生产的生产效率,反应温度控制为452μm;粉体性能指标符合国家电子行业标准SJ/T 1766—1997中低磁通密度下闭路铁芯制备范围的CL9F、CL10F料粉要求;考虑到工业化生产的生产效率,反应温度控制为45⁵0℃时,粉体颗粒粒径小,产品的收率最高。     

Recovery of sulfuric acid from waste aluminum surface processing solution by diffusion dialysis

Diffusion dialysis with anionic ion exchange membranes was employed to recover sulfuric acid from the waste acid solution of aluminum surface processing plant. Experiments were conducted to examine the dialyzer performances under various operating conditions, including feed flow rates, sulfuric acid concentration in the feed solution, temperature and number of pieces of ion exchange membrane. Diffusion dialysis was found very efficient for this purpose. Based on the test results, optimum operating conditions of these variables were identified. Preliminary economic evaluation of the process indicated that diffusion dialysis is highly viable for sulfuric acid recovery due to its short payback period.     

Recovery of H2SO4 from waste acid solution by a diffusion dialysis method

A diffusion dialysis method using anion exchange membrane was used to recover H2SO4 from waste sulfuric acid solution produced at the diamond manufacturing process. Effects of flow rate, operation temperature, and metal ion concentration on the recovery of H2SO4 were investigated. The recovery of H2SO4 increased with the concentration of H2SO4 and operation temperature. It also increased with the flow rate ratio of water/H2SO4 solution up to 1, above which no further increase was observed. The flow rate did not affect the rejection of Fe and Ni ions. About 80% of H2SO4 could be recovered from waste sulfuric acid which contained 4.5M free-H2SO4 at the flow rate of 0.26x10(-3) m3/hm3. The concentration of recovered H2SO4 was 4.3M and the total impurity was 2000 ppm. Preliminary economic evaluation has revealed that the dialysis system is highly attractive one that has payback period of only few months.     

Recovery of nitric acid from waste etching solution using solvent extraction

As part of our efforts to identify effective ways and means to keep source water safe, the concept of risk assessment and management is introduced in this paper to address the issue of risk assessment and management of arsenic in source water in China. Carcinogenic and non-carcinogenic risk are calculated for different concentrations of arsenic in source water using the corrective equation between potential health risk and concentration of arsenic in source water with purification process taken into consideration. It is justified through analyses that risk assessment and management is suitable for China to control pollution of source water. The permissible content of arsenic in source water should be set at 0.01 mg/L at present in China, and necessary risk management measures include control contaminated sources and improvement of purification efficiency.     

Recovery of actinides from their dioxides using organic reagents saturated with nitric acid

The TBP-HNO₃ and N,N′-dimethyl-N,N′-dioctylhexylethoxymalonamide-HNO₃ adducts effectively recovery actinides from solid solutions of their oxides in UO₂ matrix. The adduct of methyl isobutyl ketone and HNO₃ selectively recovers uranium from PuO₂-UO₂ solid solution, separating uranium from plutonium. The optimal composition of TBP-HNO₃ adducts for the recovery of actinides from the dioxide solid solutions was determined. Uranium is recovered with the adduct more rapidly at lower temperatures and smaller volume of the organic phase, as compared to the dissolution of the oxide fuel in aqueous nitric acid. This approach to the processing of spent nuclear fuel can substantially decrease the volume of highly toxic radioactive aqueous and organic wastes arising with the existing technologies.     

Recovery of rare-earth elements from nitric acid solutions by fullerene black impregnated with diphenyl(dibutylcarbamoylmethyl)phosphine oxide

The distribution of microamounts of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates between aqueous HNO₃ solutions and fullerene black impregnated with diphenyl(dibutylcarbamoylmethyl)phosphine oxide (L) was studied. The influence exerted on the efficiency of REE recovery by the HNO₃ concentration in the aqueous phase and concentration of L in the sorbent phase was examined. The degree of REE recovery increases on adding HClO₄ to the aqueous phase.     

Extraction of alkaline-earth elements from nitric acid with a solution of HDBP zirconium salt

Extraction of alkaline-earth metals with acidic zirconium salt of dibutyl hydrogen phosphate (HDBP AZS) increases in the order Ba < Sr < Ca. Magnesium is extracted substantially better than Ba, but by an order of magnitude worse than Ca. The maximal recovery of Sr is observed at Zr: HDBP ratio of 1: 9, similarly to extraction of TPE and REE. The recovery of Sr is possible from weakly acidic solutions (<0.5 M HNO₃); as the acidity increases, the Sr distribution coefficient decreases in proportion to [H⁺]^?3. The presence of TBP in the extractant slightly decreases the Sr extraction but simultaneously increases the extractant capacity. The latter effect is substantially less pronounced than for TPE and REE. In the experiment with model solutions on a bench of centrifugal extractors, the Sr decontamination factor from REE and TPE as high as 50–100 was attained.