树脂吸附法从含钼废水中回收制备三氧化钼

采用A325树脂对某含钼废水进行吸附,回收废水中的钼并制得了三氧化钼产品。整个过程分为废水中钼的吸附、解吸、除杂净化和三氧化钼的制备等几个步骤。在钼的吸附过程中,当原料液钼浓度2.8g/L时,适宜的工艺条件是:v(料液)∶v(树脂)=45∶1,料液pH值为3.0、料液温度25±2℃、料液流速10mL/min,钼的吸附率可达到94.3%。解吸时,采用10%的氨水溶液作为解吸液,v(解吸液)∶v(树脂)=2∶1进行配料。富钼解吸液再经除杂净化、酸化沉淀、过滤、洗涤、烘干、煅烧,制得三氧化钼产品。

回收制备烧结Nd-Fe-B磁体的磁性能与耐热性能

以废旧钕铁硼磁体为原料,采用短流程回收制备技术制备了烧结Nd-Fe-B磁体,通过添加镨钕混合稀土研究了磁体的磁性能和耐热性能。结果表明,在回收磁体中添加2%PrNd,制备的烧结Nd-Fe-B磁体的剩磁为1.31T、矫顽力为1 474.86kA/m、磁能积为353.90kJ/m^3。与一次成品相比矫顽力恢复到102%,剩磁恢复到95%,磁能积恢复到90%。在293~393K范围内未掺杂PrNd磁体的矫顽力温度系数为-0.589 9%/K,掺杂2%PrNd磁体的矫顽力温度系数为-0.556 4%/K,提高了磁体在高温下的耐热性能。这是由于添加混合稀土PrNd增强了主相晶粒间的去磁交换耦合作用,提高了主相的磁晶各向异性场,从而提高了磁体的矫顽力和耐热性能。

探讨不同基质农药残留分析方法的建立程序

以英国食品分析能力评价体系(FAPAS)组织的一次小麦粉中的农药残留能力验证为例,在实验室原有检测方法上进行改进,从空白加标回收试验样品的制备、分析方法的确定、上机测定、数据处理等方面,探讨了不同基质农药残留分析方法的建立程序。

Preparation of boric acid from low-grade ascharite and recovery of magnesium sulfate

Boric acid and kieserite were prepared from low-grade ascharite by sulfuric acid method.This method results in the recovery of 71.06%and 45.03%for boric acid and kieserite,respectively.Meanwhile,the boric acid was precipitated from the filtrate at low temperature and the solution was recycled without discharging waste liquid in the whole process.The influence of amount of sulfuric acid,mass fraction of sulfuric acid,reaction temperature and reaction time on the leaching rate of boric acid were studied. The results show that the leaching rate of boric acid reaches 93.80%under the following conditions:the amount of sulfuric acid is 85%of theoretical dosage;the mass fraction of sulfuric acid is 25%;reaction temperature is 95℃;and the reaction time is 100 min. Meanwhile,the effects of mass fraction of magnesium sulfate,crystallization temperature and crystallization time on the crystallization of kieserite were investigated and the optimal crystallization conditions are obtained:the mass fraction of magnesium sulfate is 28%;the crystallization temperature is 180℃and the crystallization time is 4h.

Cobalt recovery and microspherical cobalt tetroxide preparation from ammonia leaching solution of spent lithium-ion batteries

A process for recovering Co and preparing microspherical Co_(3)O_(4)through NH_(3)distillation and phase transformation from ammoniacal solution was investigated.As the basis of thermodynamics,the solubility of Co at different NH_(3)and CO_(3)^(2-)concentrations was studied,and then the effects of different NH_(3)distillation conditions on Co recovery rate were discussed.Over 94%Co and 96%NH_(3)were recovered through NH_(3)distillation,and the cobalt was precipitated in form of cobalt carbonate ammonium compound salt.Through the analysis of the formation mechanism of the precursor,the precipitation process of cobalt could be divided into two stages,and the cobalt precipitation rate was significantly accelerated in the second stage.In phase transformation,the effect of temperature on the roasted product was investigated.The microspherical Co_(3)O_(4)with a microporous structure was prepared at 300°C,and Co_(3)O_(4)with a mesoporous structure and high-spin state was obtained at 750°C.

Recovery and Recycling of Ti Supported Bimodal Mesoporous Catalysts Prepared via Ship-in-a-bottle Method in the Epoxidation of Cyclohexene

Ti/BMMs （Ti supported bimodal mesoporous silica） catalysts have been prepared via self-assembly route com- bined with ship-in-a-bottle method. The recovery and recycling performances of Ti/BMMs were investigated in the epoxidation of cyclohexene. In order to the evaluate the regeneration methods and to examine the deactivation behaviors, the deactivated Ti/BMMs catalysts were washed in chloroform or calcinated at 450 ℃ for 6 h and then activity of the recovery catalysts were examined. Meanwhile, the structure features and surface properties of the regenerated catalysts were characterized by X-ray diffraction, N2-sorption analysis, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravi- metric analysis, UV visible spectroscopy and X-ray photoelectron spectroscopy. The results showed that the typical bimodal mesoporous structure of recycled Ti/BMMs catalysts was still maintained, and the phenomenon of Ti leaching during the catalytic process and recovery was negligible. In particular, spectroscopic observations indicated that the effects of the regeneration methods on the tetrahedrally-coordinated Ti species and catalytic deactivation were remarkable. The main reasons were related to the polarities of used solvents during recovery tests, the environment medium of adsorbed water inside mesopore channels and the deposition of bulky mole- cules of by-products on the mesoporous surface.

From Rubbish to a Large Scale Industry： A Simple Fabrication of Superfiber with Multitasking Applications

In the whole earth, people increased dramatically from generation to generation which had created a large scale of broken environment so that people are facing more various types of garbage. Most of garbages are not useful and as a matter of fact, they are used to be neglected. Furthermore, many efforts have been conducted to change it by many types of recycled methods. Here, a simple technique is proposed with and without using fires to transform the useless natural or man-made rubbish things to be a superfiber as well as thin film with multitasking applications in human daily life. Since most of earth environment is covered by oceans, here the authors show how the ocean related garbage such as the crab skins, broken coral reefs and beach stones were changed to be superfiber and a multitasking device prototype.

Fabrication of cost effective iron ore slime ceramic membrane for the recovery of organic solvent used in coke production

Improvement of coking properties of sub-bituminous coal （A） and bituminous coal （B） was done using blended organic solvents, namely, n-methyl-2-pyrrolidinone （NMP） and ethylenediamine （EDA）. Various solvent blends were employed for the coal extraction under the total reflux condition. A low-cost ceramic membrane was fabricated using industrial waste iron ore slime of M/s TATA steel R＆D, Jamshedpur （India） to separate out the dissolved coking fraction from the solvent-coal mixture. Membrane separations were carried out in a batch cell, and around 75 % recovered NMP was reused. The fractionated coal properties were determined using proximate and ultimate analyses. In the case of bituminous coal, the ash and sulfur contents were decreased by 99.3 % and 79.2 %, respectively, whereas, the carbon content was increased by 23.9 % in the separated coal fraction. Three different cleaning agents, namely deionized water, sodium dodecyl sulphate and NMP were used to regain the original membrane permeability for the reusing.