Ethylenediamine tetramethylenephosphonic acid as a selective collector for the improved separation of chalcopyrite against pyrite at low alkalinity

Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment and associated precious metals recovery. Therefore, in this study, the green and odourless ethylenediamine tetramethylenephosphonic acid(EDTMPA) was introduced as a novel chalcopyrite collector. Flotation results from the binary mineral mixture and real ore demonstrated that EDTMPA could realize the selective separation of chalcopyrite from pyrite relative to ethyl xanthate(EX) without any depressants within the wide p H range of 6.0–11.0, and might replace the traditional high-alkaline lime process. Electrochemical and Fourier transform infrared spectra measurements indicated that the difference in adsorption performance of EDTMPA on chalcopyrite and pyrite was larger than that of EX, suggesting a better selectivity for EDTMPA. Density functional theory calculations demonstrated that there were stronger chemical bonds between P—O groups of EDTMPA and the Fe/Cu atoms on chalcopyrite in the form of a stable six-membered ring. Crystal chemistry calculations further revealed that the activity of metal atoms of chalcopyrite was higher than that of pyrite. Therefore, these basic theoretical results and practical application provide a guidance for the industrial application of EDTMPA in chalcopyrite flotation.

Crystal Structures of Co(Ⅱ) and Cu(Ⅱ) Complexes and Ammonium Salt Involving Ethylenediamine

The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N＇-bis（salicylidene）ethylenediamine with Cu（OAc）2·H2O results in the formation of Cu（II） complex III. C14H37CoNaO8 （I）： triclinic, space group P1, a = 8.6296（12）, b = 12.0291（17）, c = 12.1108（17） A, α = 75.335（2）, β = 69.991（2）, γ = 72.248（2）°, V= 1109.4（3） A3, Z = 2, ρcaloa = 1.342 g/cm3, the final R= 0.0342 for 4817 observed reflections with I 〉 2σ（I） and Rw = 0.1263 for all data. C6H16N204 （II）： space group P1, a = 5.5513（10）, b = 5.5589（11）, c = 7.4437（14） A, α = 94.332（4）, β = 104.497（4）, γ = 103.487（4）°,V= 214.06（7） A3, Z = 1, ρcalcd = 1.398 g/cm3, the final R = 0.0431 for 829 observed reflections with I〉 2σ（I） and Rw = 0.1263 for all data. C14H37CuN40 （III）, space group P21/n, a = 9.050（9）, b = 18.434（17）, c = 11.659（11） A, β = 107.134（19）°, V= 1859（3） A3, Z = 4, ρcalcd =1.443 g/cm3, the final R = 0.0616 for 3308 observed reflections （O 〉 2σ（I）） and Rw = 0.1229 for all data. Their structures were all determined by X-ray diffraction, elemental analysis and IR.

STUDIES OF THE INITIATION MECHANISM OF VINYL POLYMERIZATION WITH THE SYSTEM PERSULFATE/N-ALKYL SUBSTITUTED ETHYLENEDIAMINE DERIVATIVES

Effects of N-alkyi substituted ethylenediamine derivatives on vinyl polymerization using persulfate as initiator were studied. The apparent kinetic equations and overall activation energies of acrylamide polymerization were determined using the above mentioned system as initiator. The promoting activities of different diamine derivatives on vinyl polymerization are in the order of tertiary diamine>secondary diamine>primary diamine. Diamines having methyl groups as the substituent on their nitrogen atom possess higher promoting activity than that of having larger alkyl groups. The initial free radicals produced through the redox reaction of persuifate and diamines were studied by spin strapping technique and ESR spectroscopy. The results obtained confirm the fact that the initial free radicals of the diamine species can initiate vinyl polymerization and become the amino end group of the resulting polymers.

α-Oxoketene Cyclic S, S-cetals Chemistry-Substitution Reaction of α,α'-Dicinnamoyl Ketene Cyclic S, S-Acetals with Ethylenediamine

α,α'-Dicinnamoyl ketene cyclic S, S-acetals 4 were reacted with ethylenediamine to afford α,α'-dicinnamoyl ketene cyclic N,N-acetals 5. This process provides a new method for thesynthesis of 5 in high yield under mild conditions.

Synthesis,Crystal Structure and Antimicrobial Study of N,N,N'-Tris(3-aminopropyl)ethylenediamine Copper(Ⅱ) Diperchlorate

The title compound [Cu（C11H29N5）]（ClO4）2 was synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The compound crystallizes in the monoclinic system, space group P21/n with α = 9.405（2）, b = 14.495（3）, c = 14.715（3） A, β= 90.262（3）°, V=2006.1（7） A^3,M,=493.83,Z=4,F）（000）= 1028,Dc= 1.635 g/cm^3, T= 298（2） K,μ= 1.403 mm^-1 and = 0.71073 A. The was refined to R = 0.0508 and wR = 0. 1250 for 2293 observed reflections with I 〉 2σ（I）. The Cu（Ⅱ） atom possesses a five-coordtinate CuN5 environment which shows a slightly distorted square-pyramidal geonetry. Antimicrobial activity study found that the complex is active against Salmonella species, Staphylococcus aureu, Bacillus pumilus and Bacillus coliforms.

STUDY ON THE SYNTHESIS AND PROPERTIES OF MACRORETICULAR IPN POLYACRYLAMIDE—POLY(VINYL—ETHYLENEDIAMINE)CHELATE SORBENTS

A new series of MR-IPN polyacrylamide—poly(vinyl-ethylenediamine)chelate sorbents were prepared by the reaction of ethylenediamine with MR-IPN matrixes.The new chelate sorbent showed good sorption properties for auric and platinic ions.

α-Oxoketene Cyclic S,S-Acetals Chemistry──Reaction of α,α′-Dioxo (ester)ketene Cyclic S,S-Acetals with Ethylenediamine

α, α′ -Dioxo (ester ) ketene cyclic S, S-acetais 2 were reacted withethyleneddriine to chrd α, α′-dioxo (ester)ketene cyclic N, N-acetals 3 Thisprocess provides a new method for the synthesis of 3 in gnd yteld under mildcondition. All products are confirmed with elementai analpeis, IR, 1H NMR and13~C NMR

Electroless copper plating process of N, N, N, N′-tetrakis (2-hydroxypropyl) ethylenediamine system with high plating rate

Electroless copper plating process of N, N, N′, N′-tetrakis (2-hydroxypropyl)ethylenediamine(THPED) chelating agent was researched comprehensively. The results indicate that plating rate decreases with the 3H2O has a bad effect on deposits quality, but 2, 2′-dipyridyl and PEG make deposits quality improve greatly. Low concentration of 2-mercaptobenzothiozole (2-MBT) increases plating rate and improves deposits quality, but decreases plating rate and worsens deposits quality when 2-MBT reaches 5 mg/L. The optimal conditions of this electroless MBT are 16.8 g/L, 16.0 mL/L, 13.3 g/L, 0.5 g/L, 5.0 mg/L and 2.0 mg/L, respectively, pH value is 12.75,bath temperature is 30 ℃. Plating rate reaches 9.54 μm/h plating for 30 min in the bath. The SEM images demonstrate that the surface of copper film is smooth and the crystal is fine.

Synthesis and Characterization of Free and Copper (II) Complex of N,N′-<i>Bis</i>(Salicylidene)Ethylenediamine for Application in Dye Sensitized Solar Cells

Dye sensitized solar cell represents a promising method for the conversion of solar energy to electric energy. In the present work free N,N'-bis(salicyli-dene)ethylenediamine and its copper (II) complex were synthesized, characterized, and investigated for use as dye sensitizers in the fabrication of dye sensitized solar cells. The dyes were characterized using UV-Vis, Steady State Florescence, and Fluorescence Lifetime, Thermogravimetric Analysis, Differential Scanning Calorimetry, and Cyclic Voltammetry. The thermogravimetric analyses of the ligand and the ligand Copper complex demonstrate the stabilizing effect of the copper ion on the ligand complex. Additionally, the copper ion is shown to stabilize the structure, as evidenced by the 150oC increase in the extrapolated onset temperature of the decomposition event. The ligand copper complex is further stabilized by the presence of the copper, which is determined by the 6.34% residue that remained at the end of the thermogravimetric analysis, compared with 0% residue when applying the same condition for the ligand without copper. The current-voltage characteristics of the cells and the electrochemical impedance were determined. The photovoltaic performance of the solar cell devices fabricated using N,N'-bis(salicylidene) ethylenediamine dye was found to be slightly better than those produced from the copper complex. The solar to electric power efficiency of the ligand-based dye sensitized solar cell was 0.14% and that of the copper complex was found to 0.12%. Although the difference in the cell efficiency is quite small, it is obvious that the insertion of Copper into the ligand did not enhance the performance of the solar cells. The photocurrent-photovoltage results are consistent with the absorption spectra that showed a more prominent band for the ligand. The free hydroxyl groups, present in the ligand but absent from the copper complex owing to their coordination with the copper metal, could be responsible for the difference in the performance of the devices. The hydroxyl groups get attached to the TiO2 and facilitate the transfer of electrons.

Cosmetic Lifting Effect of a Formula Combining Tetrahydroxypropyl Ethylenediamine, Ononis Spinosa and Glycerin as Shown by a New 2-D Imaging Method

Facial sagging is a major aging change that affects the overall shape of the face. Sagging can negatively impact self-perception and consequently quality of life. In order to fight against this aging sign, we developed a combination of three active ingredients: Tetrahydroxypropyl Ethylenediamine (THPE), Ononis Spinosa extract and Glycerin. In a clinical study, we assessed the efficacy of this association on facial sagging and wrinkles, with a special focus on immediate and lasting effects. Thirty-nine women applied the tested product daily during an eight-week treatment period. Clinical grading by experts and a new, easy to operate, 2-D imaging method were performed at different time points. The 2-D imaging method measured the upper eyelid lifting effect. The results showed an immediate and significant improvement in sagging and wrinkle parameters;these benefits were still observed seven hours after the first application. Results also showed a significant long-term improvement. The lifting effect calculated from the 2-D pictures was 1.08 mm immediately after application;the same method showed a 1.80 mm lifting effect following the eight-week treatment period. These results suggest that a skin care product combining THPE, Ononis Spinosa and Glycerin properties may be used to reduce sagging as well as wrinkles with both immediate and long term benefits.

Thermal Behavior of N,N'-Bis[N-(2,2,2-trinitroethyl)- N-nitro]ethylenediamine

The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N,N-bis[N-(2,2,2-tri-nitroethyl)-N-nitro]ethylenediamine in a temperature-programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of this reaction are 3(1-a)2/3, 203.67 kJmol-1 and 1020.61 s-1, respectively. The critical temperature of thermal explosion of the compound is 182.2 ℃. The values of DS, DH and DG of this reaction are 143.3 Jmol-1K-1, 199.5 kJmol-1 and 135.5 kJmol-1, respectively.

One-pot synthesis of pyrrolo[1,2-a]pyrazines via three component reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives

An effective route to pyrrolo[1,2-a]pyrazines is described via reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives in the presence of 20 mol%of sulfamic acid.

Capillary Electrophoresis for the Simultaneous Determination of Metals by Using Ethylenediamine Tetraacetic Acid as Complexing Agent and Vancomycin as Complex Selector

A new separation system of capillary electrophoresis for the simultaneous determination of metals by using ethylenediamine tetraacetic acid （EDTA） as complexing agent and employing vancomycin as complex selector was described. The Z-shape cell capillary electrophoresis was used to enhance the sensitivity for the determination of the complexes of Cu（Ⅱ）, Ni（Ⅱ）, Co（Ⅱ） and Fe（Ⅲ） with EDTA. The partial filling method （co-current mode） was used in order to increase the selectivity of the electrophoretic method, meanwhile vancomycin was not present at the detector path during the detection of metal-EDTA complexes. The vancomycin concentration, phosphate concentration and pH of the buffer strongly influenced mobility, resolution and selectivity of the studied analytes. Under the optimal condition, the relative standard deviations （n=5） of the migration time and the peak area were less than 3.14% and 7.35%, respectively. Application of the Z-shape cell capillary electrophoresis method with UV detection and vancomycin loading led to the reliable determination of these metal ions in tap water and the recoveries were 97%-101%. The detection limits based on a signal to noise ratio of 3 ： 1 were found in the range of 2-10 μg·L^-1.

Water-soluble pillar[4]arene[1]quinone: Synthesis, host-guest property and application in the fluorescence turn-on sensing of ethylenediamine in aqueous solution, organic solvent and air

Water-soluble pillar[5]arenes are a class of typical macrocycles and have aroused tremendous attention for its easy to modify, abundant host-guest properties and extensive applications. However, up to now, all the reported water-soluble pillar[5]arenes acted as the host molecules, whereas they failed to be postsynthetically modified, which seriously impeded the development of the pillar[5]arene-based supramolecular chemistry. In this work, a new water-soluble pillar[5]arene, pillar[4]arene[1]quinone, was designed and synthsized with eight quaternary ammonium groups as well as a quinone units. Such a new water-soluble pillar[4]arene[1]quinone was capable of forming 1:1 stable complex with sodium 1-octanesulfonate in aqueous solution. Since the 1,4-quinone unit of WP[4]Q[1] could react with ethylenediamine (EDA) to form a conjugated quinoxaline structure, so pillar[4]arene[1]quinone could apply to the facile fluorescence turn-on sensing of EDA in aqueous solution, organic solvent and air.

Application of EDTMPS as a novel calcite depressant in scheelite flotation

In this study, the innovative use of ethylenediamine tetramethylene phosphonic sodium(EDTMPS) as a calcite depressant in scheelite flotation was investigated by flotation experiments, and its selective depression mechanism was revealed by contact angle measurement, FTIR analysis, Zeta potential test and XPS analysis. The flotation experiment results showed that scheelite and calcite could be efficiently separated under the following conditions: pulp p H=9.5, Na OL concentration of 1.5×10^(-4)mol/L, EDTMPS concentration of 3.0×10^(-5)mol/L, a scheelite concentrate with WO3grade of 65.49%, recovery of 83.29%and separation efficiency of 65.29% could be obtained from the artificially mixed minerals. The analysis results of mineral surface properties demonstrated that EDTMPS was strongly adsorbed onto the calcite surface through the reaction between the phosphonate group and the calcium ions, which hindered Na OL adsorption and increased the hydrophilicity of calcite. However, EDTMPS had weak adsorption strength on the scheelite surface, which didn’t affect further adsorption of Na OL, hence, the scheelite remained hydrophobic. Consequently, the selective adsorption of EDTMPS on the two minerals’ surfaces increased a difference in wettability and thus enabling them to be separated by flotation. Finally, the mechanism model of this flotation separation process was established.

Effect of Amine Type on Lignin Modification to Evaluate Its Reactivity in Polyol Construction for Non-Isocyanate Polyurethanes(NIPU)

Polyols are groups of organic compounds which contain carbon and are randomly linked to other atoms,especially carbon-carbon and carbon-hydrogen.These compounds are mainly used as reactants to make other polymers.Among biopolymers,lignin is regarded as the base of a new polymer in polyol construction.The present study aimed to investigate the effects of amine type(diethylenetriamine and ethylenediamine)on the modification of lignin-based polyols,so as to provide an alternative to petroleum polyols and,in turn,increase functional groups and reduce their harm to humans’health and the environment.To this aim,first,lignin was extracted from raw liquor.Next,the extracted lignin was reacted with diethylenetriamine(DETA)and ethylenediamine(EDA).Finally,the Mannich method was used for the reaction between amine lignin and propylene carbonate.The results of the Fourier Transform Infrared(FTIR)spectroscopy analysis showed that modification with DETA led to more structural change in lignin and peak 1100 indicates the presence of C–O bond related to urethane bonds in modified lignin.Moreover,adding propylene carbonate to aminated lignin did not result in much change in the results of the FTIR analysis.Additionally,urethane bonds can be seen in the results of GPC at 400℃–500℃.Furthermore,a slight decrease in thermal stability was observed in lignin modified with amine and propylene carbonate,compared to the raw lignin sample.

Profile improvement during CO_2 flooding in ultra-low permeability reservoirs

Gas flooding such as CO2 flooding may be effectively applied to ultra-low permeability reservoirs, but gas channeling is inevitable due to low viscosity and high mobility of gas and formation heterogeneity. In order to mitigate or prevent gas channeling, ethylenediamine is chosen for permeability profile control. The reaction mechanism of ethylenediamine with CO2, injection performance, swept volume, and enhanced oil recovery were systematically evaluated. The reaction product of ethylenediamine and CO2 was a white solid or a light yellow viscous liquid, which would mitigate or prevent gas channeling. Also, ethylenediamine could be easily injected into ultra-low permeability cores at high temperature with protective ethanol slugs. The core was swept by injection of 0.3 PV ethylenediamine. Oil displacement tests performed on heterogeneous models with closed fractures, oil recovery was significantly enhanced with injection of ethylenediamine. Experimental results showed that using ethylenediamine to plug high permeability layers would provide a new research idea for the gas injection in fractured, heterogeneous and ultra-low permeability reservoirs. This technology has the potential to be widely applied in oilfields.

Amine-immobilized HY zeolite for CO_(2) capture from hot flue gas

Solid amine-based adsorbents were widely studied as an alternative to liquid amine for post-combustion CO_(2)capture(PCC).However,most of the amine adsorbents suffer from low thermal stability and poor cyclic regenerability at the temperature of hot flue gases.Here we present an amine loaded proton type Y zeolite(HY)where the amines namely monoethanolamine(MEA)and ethylenediamine(ED)are chemical immobilized via ionic bond to the zeolite framework to overcome the amine degradation problem.The MEA and ED of 5%,10%and 20%(mass)concentration-immobilized zeolites were characterized by X-ray diffraction,Fourier-transform infrared spectroscopy,and N_(2)-196℃ adsorption to confirm the structure integrity,amine functionalization,and surface area,respectively.The determination of the amine loading was given by C,H,N elemental analysis showing that ED has successfully grafted almost twice as many amino groups as MEA within the same solvent concentration.CO_(2)adsorption capacity and thermal stability of these samples were measured using thermogravimetric analyser.The adsorption performance was tested at the adsorption temperature of 30,60 and 90℃,respectively using pure CO_(2)while the desorption was carried out with pure N_(2)purge at the same temperature and then followed by elevated temperature at 150℃.It was found that all the amine@HY have a substantial high selectivity of CO_(2)over N_(2).The sample 20%ED@HY has the highest CO_(2)adsorption capacity of1.76 mmol·g^(-1)at 90℃ higher than the capacity on parent Na Y zeolite(1.45 mmol·g^(-1)only).The amine@HY samples presented superior performance in cyclic thermal stability in the condition of the adsorption temperature of 90℃ and the desorption temperature of 150℃.These findings will foster the design of better adsorbents for CO_(2)capture from flue gas in post-combustion power plants.

CONDENSATION OF 1,2-DIAMINES AND CARBOXYLICACIDS UNDER MICROWAVE IRRADIATION

A facile method of preparation of benzimidazoles by microwave irradiation was described. The mixtures of o-phenylenediamine and carboxylic acids were heated by microwave irradiation, to give 2-substituted benzimidazoles with yields of 49%～93%. The reaction time was shortened to 3～6 min. However, the reaction of ethylenediamine with carboxylic acids did not give imidazoles but the N,N-diacyl ethylenediamines. The alphatic diamines lacked the activity to form imidazole ring. With adipic acid, intermolecular acylation took place to afford poly(ethylene adipamide).

Hydroxy- and Aminoethyl Imidazolines of Cottonseed Oil Fatty Acids as Additives for Diesel Fuels

In the research, aminoethyl imidazolines of cottonseed oil fatty acids with diethylenetriamine have been synthesized using the ultrasonic device creating the effect of cavitation. The yield of imidazolines was 90% - 95%. The influence of the synthesized imidazolines on lubricity quality of low sulfur diesel fuels having low lubricating quality was studied. The results showed that at concentrations 200 - 250 ppm the synthesized imidazolines can be applied as additives enhancing lubricity quality of diesel fuels.