表面活性剂法分离皂脚混合脂肪酸

表面活性剂法分离皂脚混合脂肪酸,系国内外比较先进的分离方法.本文通过分离工艺参数的探讨、中试车间设计和试生产,着重介绍分离原理、影响分离效果的主要因素,分离工艺、主要设备及产品质量指标.     

复合活化剂组分质量比对活性炭微球电容性能的影响

为了制备高体积比电容活性炭微球(AMCMB),以KOH/NaOH为复合活化剂,在850℃下对中间相沥青微球(MPMB)进行活化处理。考察了KOH/NaOH复合活化剂不同组份质量比对AMCMB收率、振实密度及比电容的影响。结果表明:随着NaOH含量的增加,AMCMB的比电容呈现先增加后减小的趋势,并在质量比ζ(KOH:NaOH)=5:1时达到最大值81F/cm3,其孔径以微孔为主,中孔含量较高,平均孔径约为2.21nm,比表面积达2788m2/g,适合用作超级电容器电极材料。     

复合激发剂激发的碱矿渣混凝土的应用研究

本文通过使用市场销售的S95级矿粉、复合激发剂、水、砂、石以及现有传统水泥混凝土生产设备,实现碱矿渣混凝土工业化生产,并研究该碱矿渣胶结材的性能特点,认为其生产方便、性价比较高,可以在场地硬化、道路混凝土方面推广应用.     

Rheology of alkali-activated slag pastes. Effect of the nature and concentration of the activating solution

An understanding of the rheological behaviour of OPC-based products has been widely studied, for it is essential to determining and predicting the fresh and hardened characteristics and properties of pastes, mortars and concretes. The rheology of alkali-activated material (AAM) systems has been much less intensely researched, however.The present study aimed to ascertain the effect of factors such as the nature and concentration of the alkaline activator on the rheological behaviour of alkali-activated slag (AAS) pastes, with a comparison between the rheological parameters and fluidity of these pastes to the same parameters in OPC. More specifically, the study explored how paste rheology was affected by the nature of the alkaline activator (NaOH, 50/50 wt% NaOH/Na₂CO₃ or waterglass – Wg), its concentration (3–5% Na₂CO₃ of slag weight) and, in the waterglass solution, the SiO₂/Na₂O ratio.The findings showed that AAS paste rheology is affected by the nature of the activator. The rheological behaviour in AAS pastes activated with NaOH alone or combined with Na₂CO₃ was similar to the rheology observed in OPC pastes, and fit the Bingham model. Conversely, the AAS pastes activated with waterglass fit the Herschel–Bulkley model and their rheology proved to depend on both the SiO₂/Na₂O ratio and the Na₂O concentration. Moreover, regardless of the activator used (NaOH, Na₂CO₃ or waterglass), an increase in Na₂O concentration implies a raise of shear stress.The formation of primary C–S–H gel in Wg–AAS and its effect on paste rheology were confirmed. Gel formation was likewise shown to be related to the SiO₂/Na₂O ratio and activator concentration.     

污泥含炭吸附剂的制备工艺优化及性能表征

采用先活化剂浸泡活化在干燥热解炭化的化学活化法制备污泥含炭吸附剂.实验结果表明,有机污泥在活化温度为450℃、ZnCl2药剂和干泥质量比为0.7:1、活化时间为1.5 h、锯末添加剂投加量为2%的条件下,制得的含炭吸附剂碘值在510 mg/g以上,收率>60%,比表面积>390 m2/g.由扫描电镜观察可见孔径分布以微孔和中孔为主.     

Effect of Lanthanum and Cerium on Expression of RSCU-PA-32k Gene in Saccharomyces Cerevisiae

Ｃｕｒｒｅｎｔｌｙｔｈｅｉｎｃｉｄｅｎｃｅａｎｄｌｅｔｈａｌｉｔｙｏｆｔｈｒｏｍｂｕｓｉｌｌｎｅｓｓａｒｅｖｅｒｙｈｉｇｈ ,ａｎｄｉｔｓｅｒｉｏｕｓｌｙｔｈｒｅａｔｅｎｓｐｕｂｌｉｃｈｅａｌｔｈ .Ｔｈｒｏｍｂｏｌｙｓｉｓｉｓｏｎｅｏｆｔｈｅｒｅｌａｔｉｖｅｌｙｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄｓｔｏｔｒｅａｔｔｈｅｄｉｓ ｅａｓｅ .Ｓｉｎｇｌｅ ｃｈａｉｎｕｒｏｋｉｎａｓｅ ｔｙｐｅｐｌａｓｍｉｎｏｇｅｎａｃｔｉｖａｔｏｒ (ｓｃｕ ＰＡ 3 2ｋ )ｏｆｌｏｗｍｏｌｅｃｕｌａｒｗｅｉｇｈｔ(3 2ｋＤ)ｗａｓｄｉ…     

Analyses of the gaseous species in halide-activated cementation coating packs

The partial pressures of equilibrium gaseous species in pack-cementation diffusion processes using pure condensed Al(l), Cr(s), and Si(s) metals activated by various halide salts under Ar or reducing environments which contain different amounts of hydrogen have been calculated. The analyses indicate that the presence of hydrogen gas in the system does not significantly alter the equilibrium partial pressures of gaseous species for a pack containing Al at unit activity. In general, the partial pressures of CrCl₂ and SiCl₂ are higher in a chloride-activated pack than in a fluoride-activated pack. Therefore, the codeposition of Cr or Si with Al is possible when a chloride salt is used as the activator with a masteralloy of composition dilute in Al. The addition of hydrogen to the gas phase decreases the partial pressure of Cl₂ and thereby the partial pressures of CrCl₂ and SiCl₂. However, the presence of hydrogen and the formation of hydrogen halides and metal hydrides could increase the kinetics of the transporting processes, particularly for the coatings of Cr and Si. The study also indicates that the vapor pressures for the volatile chlorides of Fe are significantly higher than those for Ni or Co, so that displacement reactions leading to the loss of Fe from the substrate are expected for coating processes involving high halide activities.     

Synthesis of heat and ambient cured one-part geopolymer mixes with different grades of sodium silicate

The use of solid activators in the manufacture of geopolymer enhances its commercial viability as it aids the development of a one-part “just add water” geopolymer mixture, similar to the conventional Portland cement-based materials. This study is aimed to synthesize heat and ambient cured one-part geopolymer mixes. Appropriate combinations of low calcium (Class F) fly ash, slag and hydrated lime as the aluminosilicate source materials were activated by three different grades of sodium silicate and a combination of sodium silicate and sodium hydroxide powders. A conventional two-part geopolymer mix with the commonly used sodium hydroxide and sodium silicate solutions was also made for comparison. Effects of the type and amount of the solid activator, the amount of fly ash replacement with slag and hydrated lime and water content on short term mechanical properties of the heat cured one-part geopolymer mixtures including workability of the fresh mix, hardened density and compressive strength were evaluated. Subsequently, effects of ambient curing on the properties of the developed one-part geopolymer mixes were also investigated. Moderate to high compressive strength of over 37 MPa developed for the heat and ambient cured one-part geopolymer mixes. The 28-days compressive strengths of the ambient cured one-part geopolymer mixtures, regardless of the type of activator and geopolymer source materials, were comparable to those of the counterpart heat cured one-part geopolymer mixes. Such one-part geopolymer mixes could enhance the commercial viability and large-scale applications of the geopolymer in the construction industry.     

利用钛矿渣制备超轻发泡混凝土的研究

利用普通硅酸盐水泥与钛矿渣,采用化学发泡工艺制备了干密度小于250 kg/m3的发泡混凝土,研究了钛矿渣、水胶比以及激发剂对发泡混凝土抗压强度的影响,同时对发泡混凝土气孔结构及微观结构进行了分析。结果表明:随着粉磨90 min的钛矿渣掺量增加,发泡混凝土28 d及56 d抗压强度先提高后降低,掺量为15%时达到最高;掺入6%的激发剂有利于钛矿渣发泡混凝土抗压强度的提高。粉磨90 min的钛矿渣取代30%的水泥,并掺入6%的激发剂制备的发泡混凝土干密度为243.0 kg/m3,28 d及56 d抗压强度分别为0.48 MPa、0.52 MPa;掺入30%钛矿渣与6%激发剂一定程度上减小了气孔孔径,改善气孔均匀性,提高了孔间壁致密程度。     

都龙矿区螺旋溜槽尾矿中锡石回收工艺试验研究

都龙矿区新田选矿厂+37μm粗粒级锡石重选工艺中螺旋溜槽尾矿采用摇床重选的作业回收率仅35%左右,难以达到高效回收细粒级锡石的目的。鉴于细粒锡石浮选工艺技术在生产中已获得成功应用,采用浮选工艺回收螺旋溜槽尾矿中锡石可以获得锡粗精矿含锡品位8.03%、作业回收率89.23%的试验指标,相对摇床重选工艺能大幅度提高锡石的回收率。同时将浮锡尾矿尾水回用,在获得相近指标的条件下,可降低药剂耗用量10%~20%,有利于降低药剂成本。