N,N-二甲基-N-丙烯基十六烷基溴化胺的合成及表征

红外光谱、核磁共振氢谱和质谱证实,以溴代丙烯与N,N-二甲基十六烷基胺为主要原料所合成的产品为阳离子表面活性剂单体N,N-二甲基-N-丙烯基十六烷基溴化胺,并且其纯度很高.     

N，N-二甲基-N-丙烯基十六烷基溴化胺的合成及表征

红外光谱、核磁共振氢谱和质谱证实,以溴代丙烯与N．N-二甲基十六烷基胺为主要原料所合成的产品为阳离子表面活性剂单体N,N-二甲基-N-丙烯基十六烷基溴化胺,并且其纯度很高．     

邻硝基苯基萤光酮-溴化十六烷基三甲基铵分光光度法测定微量铬

本文研究了在表面活性剂(CTMAB)存在下,邻硝基苯基萤光酮与铬(Ⅵ)的显色反应。在pH=5.4—6.3范围内铬(Ⅵ)与O-NPF形成稳定的兰色络合物,最大吸收波长为590nm,表观摩尔吸光系数1.26×10~5摩尔~(-1)·升·厘米~(-1),铬在0—7微克/50毫升范围围服从比尔定律,络合物组成Cr∶O-NPF=1∶2。本法可用于化工厂废水和钢铁中微量铬的测定。     

N,N-二羟乙基十二胺对赤铁矿和石英的浮选性能研究

以赤铁矿反浮选脱硅体系为载体,通过单矿物浮选试验和人工混合矿分选试验考察了N,N-二羟乙基十二胺对赤铁矿和石英浮选行为的影响。单矿物浮选试验结果表明,N,N-二羟乙基十二胺对石英具有很好的捕收能力,在矿浆自然pH、N,N-二羟乙基十二胺用量大于13.33 mg/L时,石英回收率保持在90%以上;N,N-二羟乙基十二胺对赤铁矿的捕收能力较弱,在考察的捕收剂用量范围内,赤铁矿回收率不超过70%。人工混合矿分选结果表明,在矿浆自然pH、N,N-二羟乙基十二胺用量为20 mg/L、淀粉用量为3.33 mg/L条件下,可获得精矿铁回收率为86.86%、铁品位为65.28%的分选指标;N,N-二羟乙基十二胺可应用于石英和赤铁矿矿物的浮选分离。动电位测试结果表明,N,N-二羟乙基十二胺在石英表面发生了静电吸附。     

偶氮氯膦Ⅲ──溴化十六烷基三甲基铵──α-噻吩甲酰三氟丙酮体系光度法测定瓷土中离子吸附型稀土元素总量

研究了偶氯氯膦Ⅲ（CPAⅢ）-溴化十六烷基三甲基铵（CTMAB）──α-噻吩甲酰三氟丙酮（TTA）显色体系和测定瓷土中离子吸附型稀土元素总量的条件．配合物组成比为Ce：CPAⅢ:CTMAB＝1:2:4；摩尔吸光系数εCe＝6．04×104L·mol-1·cm-1,εy＝5．45×104L·mol-1·cm-1．相对标准偏差为0．58％（n＝7）,加料回收率99％．     

N,N二烷基取代酰胺与三辛基氧膦从硝酸底液中萃取铀(Ⅵ)的研究

本文研究N,N二正戊基乙酰胺(DPAA)、N,N二正辛基乙酰胺(DOAA),N,N二正戊基丙酰胺(DPPA)、N,N二甲庚基乙酰胺(N503)从硝酸底液中萃取U(VI),实验分别测得单元平衡常数logβ_(10)依次为0.218,0.639,0.702和0.955。文中还测定了三辛基氧膦TOPO莘取U(VI)平衡常数logβ_(20)=2.87。本文还研究了二元体系DPAA+TOPO与N503+DPAA萃溶液萃取UO_2(NO_3)_2,实验发现有BB类二元协同萃取,其协萃平衡常数为logβ_(12)=1.03(DPAA+TOPO体系):logβ_(13)=1.36(DPAA+N503)。     

甲烷在表面活性剂水溶液中溶解度的实验研究

在进行煤层注水或巷道喷雾时,若改变水溶液性质使之能够吸收甲烷,则可有效降低煤层瓦斯含量,实现煤层消突.研制加工了瓦斯溶解实验装置,选择增溶能力较强的不同类型表面活性剂,进行了不同温度、体积分数和压力条件下的甲烷溶解实验测试.结果表明,甲烷溶解度均随体积分数的增大呈对数增大,随温度的升高呈逆指数降低,随压力的升高呈对数增加;加入聚丙二醇甲烷溶解度最大,常温常压下,体积分数为10％的溶解度为24.66 mL/100 mL溶液,是纯水的7.45倍,4种表面活性剂增溶能力的顺序为:聚丙二醇＞聚乙烯醇＞十二烷基硫酸钠＞F-500.根据实验结果建立了不同条件下甲烷溶解度的计算方程,估算值和实验值吻合较好,为矿井水力化措施提高瓦斯治理效果提供了依据.     

Hydrophobic aggregation of alumina in surfactant solution

The aggregation behavior of ultrafine alumina in surfactant solution is examined by particle size analyzer. Electrokinetic and contact angle measurements are used to discuss the adsorption mechanism of sodium dodecyl sulfate (SDS) and dodecylamine (DDA) chloride at alumina. The PZC value of alumina is 9.1. SDS and DDA made alumina surface hydrophobic, respectively at pH < PZC and pH > PZC, and hydrophobic aggregation between alumina particles take place. The interfacial interaction energies between alumina particles in solution have been obtained based on polar interfacial interaction theory and contact angle measurements. The classical DLVO theory only considering the electrostatic and van der Waals interaction fails to explain the hydrophobic aggregation of ultrafine alumina, which can be well explained in the extended DLVO theory concerning polar interfacial interaction.     

密度-温度关联法在硝酸铵溶液浓度在线测量中的应用

在使用硝酸铵水溶液配制炸药水相原料过程中,需要实时、快速在线测量硝酸铵溶液的浓度。利用质量流量计能同时测量液体密度、温度的功能,参照硝酸铵溶液的物性数据,由控制器依据密度-温度关联法,对硝酸铵溶液浓度进行在线测量,实现了快速、准确配制水相原料的目的。通过在配料过程中的实际运用,证明了本方法的实用性。     

粉煤灰在处理水溶液中铬的应用

粉煤灰是一种可再资源化的工业固体废弃物,在建材、化工、农业和环保等领域都有广泛的用途。本文介绍了当前粉煤灰及其改性产品在处理含铬水溶液中的应用现状,讨论了温度、pH值、接触时间、铬离子浓度和粉煤灰用量对粉煤灰吸附性能的影响,介绍了粉煤灰对Cr(Ⅵ)和Cr(Ⅲ)的去除机理。     

Degradation of thiocyanate in aqueous solution by persulfate activated ferric ion

Thiocyanate formation from cyanidation of gold bearing ores is becoming a more common problem during gold processing. In this work, the application of an advanced oxidation process based on the use of persulfate (S₂O₈²⁻) as an environmentally friendly oxidant in the presence of ferric ion for destruction of a persistent and non-volatile inorganic contaminant, such as thiocyanate, in aqueous solutions is reported for the first time. The influence of various reaction parameters like ferric ion and persulfate dosage, initial thiocyanate concentration and the influence of radical scavenger are examined. An accelerated reaction using S₂O₈²⁻ to destroy thiocyanate can be achieved via chemical activation with Fe³⁺ to generate highly reactive sulfate anion-radicals (SO₄⁻). The results showed that degradation efficiency was negligible when persulfate was used alone, ferric ions significantly improved the degradation efficiency of thiocyanate at ambient temperature. Under the optimum molar ratios ([S₂O₈²⁻]:[SCN⁻] = 5:1 and [S₂O₈²⁻]:[Fe³⁺] = 1:0.2), 99% of thiocyanate present in aqueous solution at the initial concentration range of 1.72–17.2 mM was degraded within 60 min of reaction time. To evaluate the contribution of reactive free radicals generated through Fe(III)-mediated activation of persulfate to thiocyanate degradation, quenching experiments using methanol as the radical quenching agent were carried out. The obvious decrease in thiocyanate oxidation efficiency in the presence of methanol confirmed that the radical-based pathway was the dominant mechanism in Fe³⁺/S₂O₈²⁻ system. The degradation of thiocyanate was accompanied by the formation of cyanide as the main final product of the reaction. Thus the catalytic oxidation of thiocyanate makes it possible to return NaCN into the production process for leaching of precious metals. The work presents an efficient and environmentally acceptable wastewater treatment process applicable in mining facilities utilizing cyanidation of sulfide ores and/or concentrates.     

宁明膨润土对水中铜离子的吸附行为

为开发广西宁明膨润土资源在重金属离子废水治理方面的用途,研究了该膨润土对水溶液中Cu2+的吸附行为。静态吸附试验结果表明,该膨润土对Cu2+的吸附速率快,吸附平衡时间短,单位质量吸附量随温度、溶液初始Cu2+浓度及一定范围内溶液初始pH值的提高而增加;试验数据与有关数学模型的拟合结果表明,吸附动力学特性符合准二级动力学方程,等温吸附特性更符合Langmuir等温式;热力学参数计算结果表明,吸附过程为自发的吸热过程。     

Cleaner production of ammonium paratungstate by membrane electrolysis-precipitation of sodium tungstate solution

The production of ammonium paratungstate(APT) is riddled with the generation of wastewater,which causes environmental problems.To solve the problem of wastewater generation at source,a membrane electrolysis-NH₃·H₂O precipitation method,which prevents wastewater generation and recycles the reagents used in the process,was proposed and investigated in this study.The electrolysis process was investigated based on parameters such as initial cathodic and anodic NaOH concentratio...     

表面活性剂改性膨润土吸附水中六价铬

采用十六烷基三甲基氯化铵(HTMAC)作为有机改性剂制备有机改性膨润土(HTMAC-Bent),用于吸附水中六价铬(Cr(Ⅵ)),并考察了反应时间、初始p H值、投加量、初始浓度、温度等影响因素对HTMAC-Bent吸附水中Cr(Ⅵ)的影响。试验结果表明,HTMAC-Bent对水中Cr(Ⅵ)的吸附具有较好p H值适应性,去除率可达90%以上,投加量和初始浓度对吸附过程影响显著。     

Dispersion of kaolinite and talc in aqueous solution: nano-morphology and nano-bubble entrapment

Nano-morphological structure of well-crystallised kaolinite, micronised talc and micronised talc ground in a ring mill has been compared using field emission scanning electron microscopy (SEM) and atomic force microscopy (AFM). The kaolinite and ground talc dispersed in water immediately after shaking whereas the majority of the micronised talc remains at the air–water interface. AFM micrographs revealed more three-dimensional details of growth steps and attached colloid particles on basal planes of the crystallites than high resolution SEM micrographs. Two-dimensional ordered surface structure on the molecular level was measured by AFM. There are major differences in nano-morphology and surface structure between these three samples. The compact, blocky kaolinite crystals show large, relatively flat (<1.5 nm) basal planes with distinctive step growth on their surfaces. The irregular, thin, curved platelets of the micronised talc have much less complex surface structure with flat, smooth basal surfaces. Micronised talc platelets have much larger aspect ratios than either kaolinite or the ground talc. For micronised talc, the total edge contribution to the specific surface area is 13% whereas ground talc and kaolinite edges contribute 21% and 30–50%, respectively. The low edge contribution to total surface area in micronised talc contributes to its poor dispersion. Highly porous re-entrants and folds are frequently displayed at the edges and between sheets of the micronised talc. These voids, observed in both SEM and AFM micrographs, are filled by air nano-bubbles causing poor dispersion and high floatability when the talc is mixed with water. After grinding, the micronised talc particles are smaller, have reduced aspect ratios and much reduced porosity at edges and between sheets. Hence, the morphological differences in aspect ratio and air entrapment in the porous structure of talc are possible causes for the poor dispersability of micronised talc in comparison to kaolinite and ground talc samples.