首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
轻烧粉-氢氧化钠法制备氢氧化镁的研究   总被引:2,自引:1,他引:1       下载免费PDF全文
以轻烧粉经酸化、氧化除铁等精制过程得到的氯化镁溶液为原料,以氢氧化钠为沉淀剂制备氢氧化镁。研究了pH值对轻烧粉酸化除铁的影响,考察了原料的物质的量比、反应温度、加料时间、陈化时间等因素对产品质量的影响,得到了轻烧粉精制和反应制备氢氧化镁的最佳工艺条件。采用扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)和激光粒度分布测试仪等对实验产品进行表征。结果表明,该工艺制备的氢氧化镁纯度达到98%以上,CaO质量分数低于0.1%,颗粒呈片状结构,粒度分布均匀,形貌规则。  相似文献   

2.
通过响应曲面法(RSM)对粉煤灰与硫酸铵焙烧产物的浸出液进行除铁工艺参数的优化.以反应温度、溶液pH值和晶种加入量为变量,反应后溶液中铝离子质量浓度和铁离子质量浓度为相应变量,分别对黄铵铁矾法除铁过程和针铁矿法除铁过程建立相应的数学模型,并对影响因素进行了分析.通过实验对模型进行了检验,其误差在5%以内,表明模型具有一定的可靠性.对模型进行求解后,分别得出黄铵铁矾法除铁和针铁矿法除铁最佳工艺条件.  相似文献   

3.
以11-氰基十一酸(11-CUA)的纯度和收率为目标函数,采用三种不同的氧化剂精制粗品11-氰基十一酸,通过对比实验及对氧化产物的红外光谱解析与熔点测定,确定了双氧水是合适的氧化剂.再利用正交试验对双氧水精制11-氰基十一酸的工艺条件进行研究,得到优化实验条件:在双氧水质量分数为15%、温度为20℃、pH值为2.0、反应时间30 min的条件下精制粗品11-CUA,产品纯度达99.86%,收率93.62%.  相似文献   

4.
以甲壳素与脱脂棉为原料,用6%质量分数NaOH和5%质量分数硫脲混合溶液作溶剂,以5%质量分数硫酸作絮凝剂絮凝得到甲壳素纤维素复合物,研究了甲壳素和纤维素的比例、甲壳素纤维素复合物的用量、吸附时间、吸附温度、溶液pH值对吸附率的影响.实验结果表明,当被吸附对象的用量是40mL10mg/L汞标液,甲壳素与纤维素的比例为2∶1、吸附剂用量为2.5g,吸附时间为2h,温度为40℃,溶液pH值为4.0时,复合物对汞离子吸附率可达94.19%.  相似文献   

5.
次氯酸钠氧化淀粉的制备工艺研究   总被引:1,自引:0,他引:1  
以木薯淀粉为原料,用次氯酸钠作氧化剂制备粉状氧化淀粉,研究了pH值、氧化剂用量、反应温度、反应时间对产品羧基含量的影响.实验条件下,最佳工艺条件的pH值为9.0、氧化剂用量为25%、反应温度为45℃、反应时间为3小时.  相似文献   

6.
为了研究煤矸石酸法提取物硫酸铝的应用及氢氧化铝精细化生产过程,进行了二段种分法制备氢氧化铝微粉的工艺研究.用煤矸石酸法提取的硫酸铝和拜耳法精制的铝酸钠稀释后的溶液反应,生成的浆液经放置老化后即得活性晶种.用活性晶种进行铝酸钠溶液的一段种子分解和二段种子分解,制备氢氧化铝微粉.同时研究了制备过程中种子浆pH、分解温度、种子比值、分解时间、铝酸钠溶液αk及铝酸钠溶液质量浓度对分解率、氢氧化铝微粉颗粒粒度的影响.结果表明,煤矸石提取物硫酸铝做晶种引发剂,在一定的工艺条件下可制得白度大于99%、Fe2O3质量分数小于0.006%、SiO2质量分数小于0.05%、吸油值小于0.70 mL/g、粒度在0.5~6 μm的氢氧化铝微粉.  相似文献   

7.
沉淀吸附法提取苦丁茶中的熊果酸   总被引:15,自引:0,他引:15  
依次用碱和酸作沉淀剂,D型树脂作吸附剂,研究了用沉淀-吸附法提取苦丁茶中中熊果酸的工艺.得到的优化条件为:将苦丁茶的乙醇提取液用质量分数为10%的NaOH溶液碱化至pH值约为10.96,过滤除去多酚等杂质,沉淀后,滤液先用体积分数为10%的H2SO4酸化至pH值为4.00,再用相同体积的pH值为4.00的酸性水溶液稀释,得到熊果酸沉淀粗产品;粗产品用甲醇溶解后,将样品溶液pH值调整为7.07,洗脱液pH值调整为11.0,用D型大孔树脂吸附,分步洗脱,收集体积分数为90%乙醇溶液的洗脱液,浓缩结晶得到熊果酸产品.采用高效液相色谱法测得沉淀分离后产品纯度为23.12%,回收率为92.90%;吸附分离后产品纯度为90.23%,回收率为98.02%,总回收率为89.09%.  相似文献   

8.
用硫铁矿烧渣制备PFC絮凝剂   总被引:3,自引:0,他引:3  
用正交实验的方法研究了用盐酸浸取硫铁矿烧渣制取三氯化铁溶液的工艺条件。浸取时间为1.2h,回流加热温度为110℃,质量分数31%的盐酸与烧渣的液固比为3.0mL/g,浸取率达96.84%,向溶液中加入少量表面活性剂PVA作稳定剂,在50℃下用氢氧化钠溶液调节羟铁尔比n(OH)/n(Fe)至0.2,可得深褐色聚合氯化铁(PFC)液体产品,产品铁质量分数11.7%,密度1.26g/cm^3,碱化度为11.6%,质量分数1%水溶液的pH值1.7,研究结果表明,PFC处理焦化废水的条件为,pH值在6~9范围内,每50mL水样中加入PFC0.3mL时除浊效果最佳,PFC性能优于PC和PFS。  相似文献   

9.
低铁硫酸铝生产新工艺研究   总被引:5,自引:0,他引:5  
介绍了利用铝灰生产硫酸铝 ,采用共沉法除铁新工艺。确定了最适宜工艺条件 :硫酸质量分数 30 % ,m( H2 SO4 ) ∶m( K2 Mn O4 )∶m A=1∶ 0 .0 0 78∶ 0 .0 0 2 6 ,p H值为 3,收率达93.2 %  相似文献   

10.
利用有机巯基类高分子螯合剂(DDTC)对氨羧络合剂电镀镉废水进行螯合处理。研究DDTC投加量,废水pH,絮凝剂投加量,反应温度,反应时间对处理效果的影响。实验结果表明在pH为3,投加DDTC溶液(质量分数2.4 g/L)20 m L,絮凝剂(硫酸铝溶液质量分数4 g/L)投加量5 m L,PAM(质量分数1 g/L,)投加量为2 m L,常温下反应10 min,可以使200 m L氨羧络合剂电镀镉废水(总镉质量浓度为30 mg/L)的镉去除率达到98.5%,残余镉的质量浓度为0.42 mg/L。  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号