Gemini双季铵盐捕收剂BDDA和EDDA对高岭石、叶腊石、伊利石浮选行为的比较及机理

采用了新型Gemini双季铵盐捕收剂丁烷-1,4-双十二烷基二甲基溴化铵（BDDA）和乙烷-1,2-双十二烷基二甲基溴化铵（EDDA）对比研究了其对高岭石、叶腊石、伊利石的浮选行为及作用机理。单矿物试验结果表明,在广泛的pH范围内,新型Gemini双季铵盐捕收剂BDDA和EDDA对三种铝硅酸盐矿物具有优异的捕收性能,且BDDA的捕收能力强于EDDA。红外光谱和动电位研究表明,Gemini双季铵盐捕收剂对三种铝硅酸盐矿物的作用机理为静电吸附和氢键作用。采用DFT密度泛函理论,在B3LYP／6—31G（d）水平上对捕收剂阳离子BDDA2＋和EDDA2＋进行量化计算,结果表明BDDA的捕收能力强于EDDA。这与单矿物浮选结果、动电位测定结果一致。     

Flotation techniques for separation of diaspore from bauxite using Gemini collector and starch depressant

The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch dep...     

直链烷基胺浮选铝硅矿物机理

研究了一水硬铝石和高岭石、叶蜡石及伊利石等几种含铝硅酸盐矿物在不同pH条件下的动电行为与浮选行为。一水硬铝石、高岭石、叶蜡石及伊利石的等电点（IEP）分别为pH6．2,4．3,2．0,3．4。在pH＞IEP时,烷基胺类阳离子捕收剂主要以静电作用吸附在一水硬铝石矿物表面,其浮选高岭石等3种铝硅酸盐矿物的可浮性大小顺序是叶蜡石＞高岭石＞伊利石。高岭石、叶蜡石和伊利石均是层状硅酸盐矿物,其破碎磨细时,将沿层间断裂,由于晶体结构的原因其层面荷负电荷。烷基胺类阳离子捕收剂以静电作用力吸附于铝硅酸盐矿物表面的层面使矿物疏水上浮。     

Aluminum-silicates flotation with quaternary ammonium salts

1　INTRODUCTIONThediasporic bauxiteinChinaisdifferentfromthegibbsite bauxiteandboehmite bauxiteinothercountriesbyitshighcontentofAl2 O3andSiO2 andlowmassratioofAl2 O3toSiO2 (massratioofAl2 O3toSiO2 =A/S ,usually5 6 ) .Theproductioncostofa luminumoxidefromsuchrefractorybauxiteby“sin tering”or“combining”technologiesismuchhigherthanthatbyBayer sprocess .Sothatthealuminum silicateganguessuchaspyrophyllite ,illiteandkaolin iteinthebauxiteisneededtoberemovedtoincreaseA/S .Hussainetal…     

N-(3-氨丙基)-月桂酰胺对铝硅酸盐矿物的浮选

研究了N-(3-氨丙基)-月桂酰胺对高岭石、伊利石和叶蜡石的浮选性能。结果表明：N-(3-氨丙基)-月桂酰胺对这些铝硅酸盐都有较好的捕收性能，对高岭石、伊利石和叶蜡石的回收率分别在91％，90％和96％以上。矿浆pH值对3种矿物的可浮性影响较小，在一个较宽的pH范围内，3种矿浆的Zeta电位均为负值，矿粒表面荷负电。红外光谱证明，3种矿物中均含有-OH基。酸性介质中，捕收剂分子通过静电引力吸附在矿粒表面；碱性介质中，捕收剂分子通过氢键吸附在矿粒表面。矿粒的扫描电镜照片表明：叶蜡石颗粒主要呈薄片状；伊利石和高岭石颗粒晕不规则形状。     

Flotation of aluminosilicate minerals using alkylguanidine collectors

The flotation mechanism of aluminosilicate minerals using alkylguanidine collectors was studied through flotation experiments, Zeta potential measurements and FT-IR spectrum analysis. It is shown that kaolinite, illite and pyrophyllite all exhibit good floatability with alkylguanidines as collectors at pH 4-12. The flotation recoveries rise with the increase of the carbon chain length. Isoelectric point(IEP) is determined to be 3.5, 3.0 and 2.3 for kaolinite, illite and pyrophyllite, respectively. However, it is anomalous that the presence of cationic collectors has less influence on the negatively charged mineral surfaces. It is explained by the special structure of guanidine which is one of the strongest bases, having two -NH2 groups. One of them maybe interacts with minerals by electrostatic forces, and the other maybe forms hydrogen bonding with OH- ions on the aluminosilicate surfaces or in the aqueous solution, increasing the density of negative charge on the aluminosilicate surface and leading unpronounced positive charge to increase on the aluminosilicate. By combining the flotation tests, Zeta potential and FTIR measurements above, the interaction mechanism can be concluded. The simultaneous presence of cationic and neutral amine groups makes it possible for SAG cation to bind on three aluminosilicate minerals by both electrostatic attraction and hydrogen bonding. While in acidic medium, the interaction of the alkylguanidines on the aluminosilicate surfaces is mainly by means of electrostatic force and hydrogen bond; in the alkaline medium, it is by the way of electrostatic effect and hydrogen bond.     

Synthesis of N-decyl-1,3-diaminopropanes and its flotation propertieson aluminium silicate minerals

1　INTRODUCTIONBauxiteisamajorsourceforaluminaproduction .Bayerprocessfeaturesshortresidencetime ,lowener gyconsumptionandhigh qualityproduct .Asare sult ,itiswidelyusedtotreatthebauxiteofalu minum/silicateratio (A/S)morethan 8.AlthoughthereareabundantaluminiumoxidemineralresourcesinChina ,mostofthemarediasporicbauxitewithhighaluminumcontent ,butlowA/Sratio .Among4 0bauxitediggings ,theaverageAl2 O3andSiO2 con tentsare 6 3.4 1%and 11.5 9% ,respectively ,whiletheaverageA/Sratiois4 6 […     

铝土矿反浮选体系分散与凝聚理论

在铝土矿反浮选脱硅过程中,矿浆悬浮液的分散和凝聚状态对微细粒－水硬铝石的回收和精矿铝硅比有显著影响。要使各种硅酸盐矿物混合物达到有效的选择性分离,首先必需使矿浆悬浮液处于最佳分散状态,避免各种矿物细粒间的相互混杂和矿泥罩盖。针对高硅铝土矿反浮选脱硅过程,根据经典DLVO理论,从颗粒间的相互作用分析了微细粒－水硬铝石在各种含硅脉石矿物表面的粘附情况。结果表明：一水硬铝石与含硅脉石矿物颗粒间的范德化相互作用总是吸引;而它们间的静电相互作用在弱碱性条件下时为排斥,在弱酸性条件下时为吸引,一水硬铝石的夹带上浮较为严重,不利于铝土矿的反浮选。     

捕收剂RL在铝土矿浮选中的应用

研究了一水硬铝石、高岭石及叶腊石等单矿物在RL为捕收剂时的浮选特性,考察了各种调整剂、难免离子对浮选体系的影响,在此基础上进行了人工混合矿和实际矿石的分离试验。实际矿石闭路试验结果表明：采用RL为捕收剂,碳酸钠和六偏磷酸钠为调整剂,精矿中Al2O3和SiO2的品位分别为70．74％和6．37％（精矿铝硅比为11．11）,Al2O3的回收率达到90．52％。     

氯化钠对铝硅矿物浮选的影响及其作用机理

采用季铵盐DTAL作捕收剂,研究了氯化钠对一水硬铝石和叶蜡石浮选的影响及其作用机理.随着氯化钠浓度的增加,叶蜡石的浮选回收率显著提高,而一水硬铝石的可浮性受其影响很小.机理研究表明:氯化钠对一水硬铝石的zeta-电位没有影响,而能显著降低叶蜡石的zeta-电位,增强捕收剂与叶腊石的静电作用,促进捕收剂的吸附而活化其浮选;叶蜡石表面电位的降低是因为氯离子对叶蜡石存在选择性吸附作用并对其结构进行插层,使得叶蜡石的层间距从0.93 nm增大至1.40 nm.溶液化学计算表明:氯化钠改变溶液的离子强度,显著降低了季铵盐阳离子表面活性剂的临界胶束浓度,使得吸附了捕收剂的矿物表面更容易疏水上浮.     

叶蜡石的矿物成分对合成金刚石的影响

通过对闽东矿区五种不同类型叶蜡石所做的化学分析及DTA、TG分析，计算出了其相应的矿物成分。将这几种叶蜡石分别制成传压介质进行了合成金刚石的实验并与北京门头沟叶蜡石作了比较，结果表明：(1)含有一定量石英(20％左右)的叶蜡石做传压介质有利于降低金刚石合成压力，提高金刚石质量；(2)结晶水含量较低的叶蜡石合成出的金刚石质量更好。作者对实验结果进行了分析并指出：在选择作为传压介质的叶蜡石时，不能只要求其硬度低、叶蜡石成分高，而应全面考虑其中所含矿物成分及其在高温高压下可能发生的变化。     

盐酸溶液中阳离子Gemini表面活性剂在碳钢表面的吸附与缓蚀性能研究

 合成并用元素分析和核磁共振(1H-NMR)表征了阳离子Gemini表面活性剂1,2-双亚甲基-双(十烷基二甲基溴化铵)和1,2-双亚甲基-双(十二烷基二甲基溴化铵)(分别简写为10-2-10和12-2-12)，并用失重法研究了1M盐酸溶液中该类表面活性剂在碳钢表面的吸附行为及其缓蚀性能.实验结果表明，其缓蚀机理为表面活性剂在钢铁表面的吸附形成单分子膜，从而阻碍了盐酸对钢铁的侵蚀，其缓蚀效率随着表面活性剂浓度的增加而增加，当表面活性剂浓度接近其临界胶束浓度时达到最大，理论计算表明，在研究的浓度范围内，盐酸溶液中该类Gemini表面活性剂在碳钢表面的吸附行为符合Langmuir吸附等温式.      

含杂原子的双子表面活性剂的合成与应用

以N,N-二甲基十二烷基胺和3-氧杂-1,5-二溴戊烷为原料合成了以3-氧杂戊基为联接基团的季铵盐型双子表面活性剂。产物的结构用红外光谱和核磁共振氢谱进行表征。测定了25℃下双季铵盐水溶液及其与NP-6、NP-8、NP-15、AEO-3的二元复配体系的表面张力。结果表明,与传统单链表面活性剂相比,双季铵盐表面活性剂具有更为优异的表面活性;每一种二元复配体系都具有显著降低表面张力的协同增效作用。与传统杀菌剂1631(十六烷基三甲基溴化铵)相比,双季铵盐表面活性剂具有更为优异的杀菌抑菌性能,其中对苹果轮纹菌、小麦赤霉菌的杀菌抑菌作用最佳。考察了弱碱性介质中双季铵盐水溶液及其复配体系对锌的缓蚀作用,结果表明:当pH值为8,双季铵盐水溶液的浓度低于20 mg/L时对锌具有较好的缓蚀作用,而高于此浓度时的缓蚀效果明显下降并表现出一定的腐蚀作用;在复配体系中,双季铵盐与NP-15的1∶1二元复配体系对锌的缓蚀作用最好。     

An impedance response model for inhibitory effect of antibiotics on bacterial growth in biometallurgy

An impedance response model reflecting the inhibitory effect of antibiotics on bacterial growth in biomet-allurgy was established. Three inhibition parameters, i.e. the maximum amount inhibitory constant of the bacterial growth(K1), the maximum specific growth inhibitory constant(K2) and the lag time inhibitory constant(K3), were included in the model. The influence of these parameters on the response curve was discussed in detail. By fitting experimental data towards the proposed model, three growth parameters (A,μm and λ) in the presence of antibiotics were gained and compared. The results show that the growth ability of bacteria is decreased due to the influence of antibiotics. The experimental and fitted curves have goodness-of-fit in the range of 0. 987-1. 008. Moreover, the kinetic growth parameters obtained from this model are closed to those from the Logistics popular growth model.These results show that the proposed model is validity to reflect the inhibitory effect of antibiotics on bacteria.     

Physicochemical and ceramic properties of clays from jebel kebar (Central Tunisia)

The mineralogical and chemical compositions and the physical properties are determined for three representative clay samples from the Sidi Bouzid area in Tunisia in order to evaluate their industrial aptitude for ceramic applications. The semi-quantitative mineralogical analysis shows that illite and kaolinite are the major clay phases associated with crystalline phases as quartz, K-feldspar and calcite. In addition, some quantities of smectite, interstratified illite–smectite, dolomite and gypsum are also detected. The chemical analysis reveals that the silica phase is relatively high. The CaO rate is approved by the mineralogical analysis. The classification of the selected clays by the Holtz and Kovacs diagram suggests their possible use in the manufacturing of the red bricks in ceramic industry. For the Geotechnical test, ceramic products were prepared by mixing the three clays with different weight proportions (40, 40, and 20% respectively for green clay, red clay and red silty clay samples).     

Nature of (001) and (001) faces and flocculation flotation of kaolinite

Flotation mechanism of kaolinite was investigated through flotation test, SEM analysis and quantum chemical simulation calculation. It is shown that the (001) face of kaolinite easily adsorb cationic collector to exhibit hydrophobicity; the (001) face is easily interacted with the reagent carrying the group of high electronegativity (-O-,-N-, F-) to show hydrophilicity. The cationic and anionic polyacrylamide are adsorbed onto the (001) face of kaolinite and the flocculation of kaolinite particles may take place; the (001) faces are exposed to interact with cationic collector to be rendered hydrophobicity. Thus, the macromolecules can evidently enhance the flotation of kaolinite in alkaline media.     

Nature of (001) and (00) faces and flocculation flotation of kaolinite

1　INTRODUCTIONThediasporicbauxiteresourceinChinaischar acterizedbyhighcontentofAl2 O3andSiO2 andlowmassratioofAl2 O3toSiO2 ,theratioisusually 5 8.ThediasporicbauxitewithlowmassratioofAl2 O3toSiO2 cannotbedirectlyprocessedbyBayer’stechnol ogy .ThesinteringorcombinationofsinteringandBayerprocessareoftenusedtotreatsuchdiasporicbauxite ,showingenergy intensiveandenvironmentalunfriendly[1] .ItisrequiredtoincreasethemassratioofAl2 O3toSiO2 toabove 10byphysicalseparationsothattheBayer…     

Synergistic effect between cationic gemini surfactant and chloride ion for the corrosion inhibition of steel in sulphuric acid

Corrosion inhibition of cold rolled steel in 0.5 mol L⁻¹ sulphuric acid by a quaternary ammonium gemini surfactant, l,3-propane-bis(dimethyl dodecylammonium bromide) (designated as 12-3-12), in the absence and presence of chloride ions was investigated at different temperatures. The results revealed significant synergistic effect between gemini 12-3-12 and chloride ions for the corrosion protection of cold rolled steel in sulphuric acid, and that the novel composite inhibitor system containing cationic gemini surfactant and chloride ions was efficient and low-cost for steel corrosion inhibition in sulphuric acid medium, even when concentration of 12-3-12 was as low as 1 × 10⁻⁶ mol L⁻¹. By fitting the obtained experimental data with Langmuir adsorption model and Arrhenius equation, some thermodynamic and kinetic parameters such as adsorption free energy, the apparent activation energy, and the pre-exponential factor were estimated. The adsorption mechanism of the gemini surfactant onto steel surface in acid medium in the absence and presence of chloride ions was also discussed, respectively.     

Morphology and photoluminescence of colloidal polypyrrole nanoparticles

In order to elucidate the origin of the photoluminescence (PL) of polypyrrole (PPy) colloids, several PPy colloidal samples were prepared under various emulsifying conditions and their PL properties were correlated with the particle morphologies. While highly aggregated fibril- or sheet-like PPy particles were obtained when a cationic surfactant [decyltrimethyl ammonium bromide (DeTAB)] and metal halide oxidant (CuCl₂) were used, employment of anionic surfactant and non-metallic oxidant [sodium di(2-ethyl-1-hexyl)sulfosuccinate (DEHSNa) and ammonium persulfate (APS)] afforded spherical PPy nanoparticles with more regularity. PL measurements of these samples indicated that the highest PL intensity is obtained from the less aggregated and smaller PPy nanoparticles. It was presumed that the smaller particles generate more localized excitons due to shorter π-conjugation length, thereby resulting in stronger PL intensity.     

十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管的细胞毒性

采用十六烷基三甲基溴化铵（CTAB）作为表面活性剂修饰羧基化的单壁碳纳米管（SWNT-COOH/CTAB）,并对原始单壁碳纳米管（SWNTs）与羧基化修饰的单壁碳纳米管（SWNT-COOH）进行材料学特征比较。通过细胞活力和细胞凋亡实验对SWNTs、SWNT-COOH和SWNT-COOH/CTAB的细胞毒性进行比较。结果表明,羧基化修饰的单壁碳纳米管比原始单壁碳纳米管的毒性小,单壁碳纳米管经羧基化后其毒性降低;浓度及时间曲线显示SWNT-COOH/CTAB的毒性与表面活性剂CTAB相关,CTAB和 SWNT-COOH/CTAB的细胞毒性在低浓度范围内（0.5-25μg/mL）是可接受的。十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管在低浓度范围（0.5-25μg/mL）内可以较安全地用于生物医学领域。