离心萃取法卤水提硼的研究   总被引：2，自引：1，他引：1       下载免费PDF全文

高成花  邓小川  张琨  王连亮  夏继平 《盐湖研究》2010,18(2)

以青海省东台吉乃尔盐湖酸化提硼母液为原料,采用CTL50-N型小流量环隙式离心萃取器,以异辛醇/磺化煤油为萃取体系萃取析硼母液中的硼。讨论了萃取剂浓度、萃取酸度、相比、流速、转速及萃取级数对萃取工艺的影响。试验结果表明,在最佳工艺参数的条件下其萃取率达到了97%以上,反萃取率在98%以上,通过酸性溶液可使硼酸浓缩到47g/L。本试验将为产业化提硼提供依据,离心萃取器在这一方面也将会有广泛的应用前景。  相似文献   

溶剂萃取法提硼研究概述   总被引：3，自引：1，他引：2       下载免费PDF全文

高成花  邓小川  张琨 《盐湖研究》2010,18(1):49-52

溶剂萃取法作为一种有效的溶液提硼方法之一,对于硼资源的开发利用、环境保护以及其它化学工业的发展具有重要意义。从萃取剂、萃取工艺和萃取设备3个方面讨论溶剂萃取法提硼的研究进展,并对今后溶液提硼的发展方向进行展望。  相似文献   

Accelerated aqueous leaching of selenium and arsenic from coal associated rock samples with selenium speciation using ultrasound extraction     

I. Pumure  J. J. Renton  R. B. Smart 《Environmental Geology》2009,56(5):985-991

Ultrasound extraction was used to compare the accelerated release rates of selenium and arsenic from three rocks (BT700, BT 571 and BT 60) that are associated with mountaintop mining and valley fill coal mining practiced in southern parts of West Virginia, USA. The concentrations of arsenic released from rocks were found to be three orders of magnitude higher than that of selenium. The accelerated leaching rate constants were ten times higher for arsenic compared to selenium. Se (IV) was found to be stable under ultrasound extraction conditions used whereas As (III) was quickly oxidized to As (V). BT700 was found to have more Se (IV) compared to BT571 while BT60 did not have any significant Se (IV) concentrations. Such compositional and kinetic information becomes important when determining suitable mining waste treatment protocols that have to be undertaken to different types of overburden before it is dumped in valleys.  相似文献   

Sustainable groundwater extraction in coastal areas: a Belgian example   总被引：1，自引：0，他引：1  

Alexander Vandenbohede  Emmanuel Van Houtte  Luc Lebbe 《Environmental Geology》2009,57(4):735-747

Water extractions in coastal areas have to deal with salt water intrusion and lowering of hydraulic heads in valuable ecosystems. Therefore, sustainable management of fresh water resources in these areas is crucial. This is illustrated here with two water extractions in the western Belgian coastal plain which extract groundwater from a phreatic dune aquifer. One water extraction faced problems with salt water intrusion, while lowering of hydraulic heads was an issue for both. To remedy the salt water intrusion, it was found that decreasing the extraction rate was the only solution. To offset this and to increase hydraulic heads around both extractions, it was decided to artificially recharge the aquifer of the second extraction with tertiary treated wastewater. By taking these interventions, the combined production capacity of the water extractions was increased with 56% whereas 27% less water was extracted from the dune aquifer itself. Extraction history and the effects of interventions are illustrated for both water extractions with water quality data and fresh water head observations. A more detailed insight in groundwater flow and fresh–salt water distribution in the aquifer is provided by simulating the evolution of the water extractions with a 3D density dependent groundwater flow model.  相似文献   

Micro-Column Separation/Pre-Concentration Combined with Fluorinating Electrothermal Vaporisation-Inductively Coupled Plasma-Mass Spectrometry for Determination of Trace Refractory Elements in Seawater, Soil and Sediment     

Chaomei Xiong  Man He  Bin Hu 《Geostandards and Geoanalytical Research》2009,33(3):385-396

A new, rapid and highly efficient method for the determination of trace amounts of refractory elements (titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum) using micro-column separation/pre-concentration combined with fluorinating electrothermal vaporisation-inductively coupled plasma-mass spectrometry (FETV-ICP-MS) has been developed. In this method, trace amounts of the analytes were selectively adsorbed by a conical micro-column packed with the solid phase extraction material N -benzoyl- N -phenylhydroxylamine loaded on microcrystalline naphthalene at desired pH values. Various factors influencing the separation/pre-concentration, such as pH, sample flow rate and sample volume were studied in detail, and the influences of the organic matrix and the pre-ashing temperature on the determined results were also investigated. Under optimal conditions, the detection limits for Ti, Zr, Hf, V, Nb, Ta and Mo were 0.016, 0.011, 0.010, 0.007, 0.005, 0.006 and 0.003 ng ml⁻¹, respectively, and the relative standard deviations ranged from 3.3% (Nb) to 9.6% (Hf) ( C = 0.20 ng ml⁻¹, n = 9). In order to validate the method, the proposed method was applied to the analysis of three certified reference materials (soils GBW07401 and GBW07425; sediment GBW07301a) and the results obtained were in good agreement with the reference values. The method was also successfully applied to the analysis of real seawater samples with satisfactory results.  相似文献   

土壤和沉积物中重金属生物可利用性的评估   总被引：4，自引：2，他引：2  

王畅  郭鹏然  陈杭亭  舒永红 《岩矿测试》2009,28(2):108-112

土壤和沉积物中重金属被植物吸收利用可通过单一化学萃取方法评估。几种重金属生物可利用态的萃取方法被用于土壤和沉积物中重金属的提取。根据实验萃取结果和文献报道,对中性盐、弱酸、螯合剂和联合萃取法进行评价,对影响生物可利用态萃取方法的因素进行讨论,并对土壤和沉积物中重金属生物可利用性评价方法的建立和有效统一使用提出建议。  相似文献   

包裹体岩片卸洗新方法—索氏抽提法     

王朴  郝运轻  谢忠怀  甄贞  李博 《岩矿测试》2009,28(1):29-31

有机溶剂在恒温常压下封闭系统内,以浸泡淋洗的原理,建立了包裹体岩片卸洗新方法——索氏抽提法,克服了以往卸洗方法手工操作不便、难洗干净、易破碎、不能大批量处理等缺点。方法具有卸洗效率高、省心省力、操作方便、环保等优点,大大地提高了包裹体岩片卸洗的质量和效率。  相似文献   

贵州平坝白云岩风化壳稀土超常富集层中稀土赋存状态的研究   总被引：10，自引：1，他引：9  

李艳丽  孙承兴  王世杰  刘秀明 《地球化学》2004,33(6):627-633

以平坝白云岩风化壳剖面为例,主要利用化学连续提取的方法,结合透射电镜的分析,对碳酸盐岩风化壳岩-土界面附近的稀土超常富集层中REE的赋存状态进行了研究,获得了REE在水溶态及可交换态(相态Ⅰ)、碳酸盐结合态及专性吸附态(相态Ⅱ)、非晶质氧化铁锰结合态(相态Ⅲ)、晶质氧化铁锰结合态(相态Ⅳ)、有机质及硫化物结合态(相态Ⅴ)和残渣态(相态Ⅵ)等6种相态的含量及变化规律.结果表明,REE在富集层中主要以专性吸附态、残渣态和有机态为主.风化前缘可溶态稀土所占比例较高,为稀土在风化壳中的迁移、转化提供可能;基岩中原生含磷稀土矿物的风化产生的稀土磷酸盐矿物的聚集导致了残渣态稀土大量存在于风化前缘;此外,由于风化淋溶的不断进行,可溶态的REE在高的pH值条件与剖面中的有机质、铁锰氧化物和粘土矿物共同作用下沉淀、富集,也导致了风化前缘稀土的超常富集.  相似文献   

Robust statistical approaches for local planar surface fitting in 3D laser scanning data     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

This paper proposes robust methods for local planar surface fitting in 3D laser scanning data. Searching through the literature revealed that many authors frequently used Least Squares (LS) and Principal Component Analysis (PCA) for point cloud processing without any treatment of outliers. It is known that LS and PCA are sensitive to outliers and can give inconsistent and misleading estimates. RANdom SAmple Consensus (RANSAC) is one of the most well-known robust methods used for model fitting when noise and/or outliers are present. We concentrate on the recently introduced Deterministic Minimum Covariance Determinant estimator and robust PCA, and propose two variants of statistically robust algorithms for fitting planar surfaces to 3D laser scanning point cloud data. The performance of the proposed robust methods is demonstrated by qualitative and quantitative analysis through several synthetic and mobile laser scanning 3D data sets for different applications. Using simulated data, and comparisons with LS, PCA, RANSAC, variants of RANSAC and other robust statistical methods, we demonstrate that the new algorithms are significantly more efficient, faster, and produce more accurate fits and robust local statistics (e.g. surface normals), necessary for many point cloud processing tasks. Consider one example data set used consisting of 100 points with 20% outliers representing a plane. The proposed methods called DetRD-PCA and DetRPCA, produce bias angles (angle between the fitted planes with and without outliers) of 0.20° and 0.24° respectively, whereas LS, PCA and RANSAC produce worse bias angles of 52.49°, 39.55° and 0.79° respectively. In terms of speed, DetRD-PCA takes 0.033 s on average for fitting a plane, which is approximately 6.5, 25.4 and 25.8 times faster than RANSAC, and two other robust statistical methods, respectively. The estimated robust surface normals and curvatures from the new methods have been used for plane fitting, sharp feature preservation and segmentation in 3D point clouds obtained from laser scanners. The results are significantly better and more efficiently computed than those obtained by existing methods.  相似文献   

地震波形的分形判别与特征提取   总被引：3，自引：0，他引：3  

解文荣  张莉 《华北地震科学》2004,22(4):22-24

研究地震波的复杂性和它的自相似性以及计算地震道时间序列分数维等一系列特征问题,能得出地震波在复杂构造及断点位置的一系列特征,能轻易地实现地震道异常点的计算机自动拾取。对更深入地研究地震波和更准确地解释地震资料,会有很大的帮助。本文提出了计算地震道分数维的一般方法。实验表明地震道时间序列的分数维在异常点会具有不同的数值,其变化点能够定量指示出异常的准确位置。这对更精确的研究时间剖面上断点及不同地质构造变化有着非常重要的意义。  相似文献