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1.
针对当前砷碱渣处理过程砷碱分离效果差、分离的砷酸钠或钙砷渣安全处置难等问题,提出“水浸-水热沉砷-碳热还原”回收金属砷新工艺。以湖南某冶炼厂砷碱渣为对象,开展砷碱渣水浸砷锑分离、氧化钙水热沉砷砷碱分离、沉砷渣碳热还原回收金属砷等环节的工艺研究。研究结果表明:在浸出时间30 min、液固比3:1、浸出温度45℃、搅拌速度600 r/min的水浸条件下,砷、锑浸出率分别为95.3%和1.6%。在初始pH=11、水热温度180℃、反应时间6 h、Ca/As物质的量比为24:1的水热沉砷条件下,沉砷率达95.3%,沉砷渣主要为碳酸钙、氢氧化钙和砷酸钙。在碳粉添加量10%、温度1 000℃、还原时间3 h条件下,砷挥发率为93.1%,挥发产物砷质量分数达92.0%。砷碱渣“水浸-水热沉砷-碳热还原”新工艺,具有可实现砷锑碱梯级分离、砷以无毒的单质砷回收、沉砷剂氧化钙可循环使用、全流程未引入难处理的阴阳离子等优点。  相似文献   

2.
控制电位氧化法铅阳极泥脱砷   总被引:5,自引:0,他引:5  
采用压缩空气和双氧水作氧化剂,通过控制氢氧化钠体系中的电位来氧化浸出铅阳极泥中的砷。试验中考察电位、NaOH浓度、反应温度、反应时间和液固质量比对脱砷效果的影响,确定碱性浸出过程中预脱砷的最佳工艺条件:NaOH浓度为2 mol/L,温度为80℃,液固质量比为5:1,通入0.2 MPa的压缩空气4 h后用双氧水调节体系的电位至-180 mV,反应时间为2 h。在此条件下,砷的浸出率可达98%以上。碱浸液经冷却过滤掉结晶砷酸钠后,返回浸出过程,砷的浸出率达98%以上,实现碱浸液的循环利用以及砷与其他金属的有效分离。  相似文献   

3.
为解决传统浸砷工艺的浸出率低和操作时间长等问题,利用次氯酸钠溶液中OH-的溶砷作用和ClO-的氧化脱硫功能,用次氯酸钠溶液作浸出剂,研究磷酸富砷渣中砷浸出时次氯酸钠溶液用量、浸出温度以及浸出时间对砷浸出率和浸出液中AsS33-氧化脱硫程度的影响规律。结果表明,与传统的碱浸和空气氧化浸出工艺相比,次氯酸钠溶液一步法的浸出时间由原来的十多个小时缩短到10 min。在次氯酸钠的用量为理论用量的4倍、浸出时间为10 min、浸出温度为30℃时,砷浸出率达98.52%,浸出液中AsS33-的硫被完全氧化脱出,实现了砷高效浸出和硫完全脱出的一步法工艺。  相似文献   

4.
采用氨浸法回收含砷石灰铁盐渣中锌,研究了不同浸取剂、浸取剂的组成、总氨浓度、氨水与铵盐配比、液固比等工艺条件对锌浸出效果的影响,分析了锌的浸出动力学.结果表明:以氨水和碳酸铵组成的浸取体系为浸取剂,当总氨浓度为5 mol/L,氨-铵盐摩尔浓度比为2∶3,液固比为4∶1时,锌的浸出率为56.21%.由宏观模型得出锌的浸出在温度为288~323 K内遵循"未反应核缩减"模型,受内扩散控制,浸出动力学方程为:1-2α3-(1-α)2/3=232×exp(-32245/RT)t,浸出表观活化能为32.24 kJ/mol.  相似文献   

5.
高砷河道尾砂还原焙烧脱砷研究   总被引:1,自引:1,他引:0       下载免费PDF全文
【目的】对河道尾砂富集分离形成的高砷尾砂进行脱砷处理,使之达到高炉冶炼的要求。【方法】在前期氧化焙烧脱砷研究的基础上,分别采用煤基还原焙烧工艺和气基还原焙烧工艺对含砷量为0.47%的河道尾砂氧化焙烧渣进行脱砷试验。考察焙烧温度、时间、还原气氛CO/(CO+CO_2)和空气流速等主要影响因子对脱砷效果的影响。【结果】气基还原焙烧的脱砷效果优于煤基还原焙烧。气基还原焙烧的适宜条件:焙烧温度900℃、焙烧时间约30min、CO/(CO+CO_2)浓度20%、气体流量0.5m3/h;在适宜的气基还原焙烧条件下,焙烧尾砂中砷的含量可降至0.058%,脱砷率达87.66%。【结论】经气基还原焙烧工艺得到的河道尾砂还原焙烧渣能满足高炉炼铁的要求。  相似文献   

6.
对苛性碱溶液氧压浸出高砷锑烟尘进行研究,考察NaOH浓度、O2分压、温度、浸出时间和液固质量比等因素对砷、锑和铅浸出行为的影响。研究结果表明:在火法处理铅阳极泥产出的高砷锑烟尘中,砷、锑的主要物相分别为As2O3和Sb2O3,锑也有少量以Sb2O5存在;在苛性碱溶液氧压浸出高砷锑烟尘过程中,As(Ⅲ)氧化为溶解度更大的As(Ⅴ)进入溶液,同时Sb(Ⅲ)氧化为Sb(Ⅴ),并形成难溶化合物Sb2O3·2Sb2O5、Pb2Sb2O7和NaSb(OH)6,进入浸出渣中;实验确定的最佳工艺条件为:NaOH质量浓度40 g/L,O2分压2.0 MPa,浸出温度140℃,浸出时间2 h,液固质量比10。在此条件下,As的浸出率可达95%以上,而Sb和Pb的浸出率均小于1.0%。  相似文献   

7.
采用氢氧化钠溶液浸出硫化砷滤饼,有效实现As与Cu和Bi等金属的分离,对浸出液经氧化脱硫后配入黑铜泥的酸性浸出液制备砷酸铜.研究结果表明:当NaOH的浓度为1.5mol/L、液固比10∶1、反应温度70℃、反应时间1.5h、搅拌速度为400r/min时,硫化砷滤饼中As的浸出率达到96.56%,Cu浸出率仅为0.12%;经氢氧化钠浸出,浸出渣中Cu、Bi的质量分数分别从原来15.93%和1.96%增加到56.31%和6.92%,使Cu和Bi得到高度富集;所制备的砷酸铜w(Cu)>29.8%,w(As)>26.19%,砷酸铜的结构式为Cu5As4O15.9H2O.  相似文献   

8.
无污染砷碱渣处理技术工业试验   总被引:6,自引:0,他引:6  
以锑冶炼产生的砷碱渣为原料,在80 ℃下,搅拌约2 h浸出脱锑;在脱锑后液中通入二氧化碳气体,脱除碳酸盐;调整脱碱后液的pH值,在酸性条件下加入适量的硫化钠脱除砷."无污染砷碱渣处理技术"工业试验结果表明:锑和铅的回收率分别达到99.0%和99.6%;砷、碱和硫酸钠的浸出率分别达到90%,99%和100%;碳酸盐中碱含量达到95%,砷含量在1%左右;砷硫化物中砷含量达到37%;在脱砷过程中产生的少量硫化氢采用氢氧化钠溶液吸收,吸收液返回脱砷系统;水溶液闭路循环,无废水外排;锑精矿、碳酸盐返回锑冶炼;砷硫化物、硫酸钡作为产品销售.采用该技术无废气、废水、废渣产生,工艺流程简单,操作条件容易控制,设备投资少.  相似文献   

9.
根据目前广西区大量砷渣得不到有效利用的现状,以磷酸净化过程中产生的含砷废渣为原料,通过物相分析确定了碱浸出法回收砷的工艺,考察了浸出温度、摩尔比、液固比和反应时间等工艺条件对砷浸出率的影响。结果表明,n(NaOH)∶n(As2S3)是影响砷浸出率的主要因素,较适宜的碱浸工艺条件为:浸出温度为70℃,n(NaOH)∶n(As2S3)=6.0∶1,液固比=6.0∶1,反应时间为30 min,在此条件下砷浸出率可达97.1%。在现有基础上,该工艺为磷酸废砷渣的综合利用提供了一条简单高效的技术路线。  相似文献   

10.
为了充分利用我国含砷铁矿资源,采用CaO+CaF2、CaC2+CaF和Si-Ca-Ba合金+CaF2对钢液进行脱砷研究,获得较高的脱砷率,其中Si-Ca-Ba合金+CaF2脱砷效果最明显,其脱砷率最高可达67.7%.在相同实验操作条件下,通过实验室研究,分析比较了温度、传质系数和S含量对不同脱砷剂脱砷效果的影响.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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