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.

Highly Sensitive Spectrofluorimetric Determination of Trace Amounts of Indium(Ⅲ) with Salicylaldehyde Salicyloylhydrazone

The fluorescent reaction of salicylaldehyde salicyloylhydrazone(SASH) with indium(Ⅲ) was studied in detail. Based on this chelation reaction, a sensitive spectrofluorimetric method was developed for the determination of indium in a water ethanol(volume ratio 3∶7) medium at pH 4 0. Under the condition, the In SASH complex displays an excitation and emission maxima at 396 and 461 nm, respectively. The linear range of the method is from 4 7 to 1000 ng/mL and the detection limit is 0 94 ng/mL. The molar ratio of indium to the reagent is 1∶1. The interferences of other ions were studied. The method was successfully applied to the determination of indium in the chemical reagents of lead, tin, zinc, zinc chloride and geological samples by standard addition method.

Spectrofluorimetric Determination of Trace Amounts of Gallium with Salicylaldehyde Benzoylhydrazone

The fluorescent reagent salicylaldehyde benzoylhydrazone(SABH) was synthesized and its ionization constants were estimated spectrophotometrically. The fluorescent reaction of this reagent with gallium was studied. Based on this chelation reaction, a spectrofluorimetric method was developed for the determination of gallium in a water medium at pH 3.2. Under these conditions, the Ga SABH complex has excitation and emission maxima at 372 and 455 nm, respectively. The linear range of the method was 0～150 μg/L and the detection limit was 0.36 μg/L of gallium when a standard addition method was used in the assay. The molar ratio of gallium to the reagent was 1∶3. The interference of other ions was studied. The extraction with n butyl acetate from a 6 mol/L hydrochloric acid medium was used to separate Ga from the interfering elements in semiconductor silicon and geological samples, and themethod has been successfully applied to the determination of gallium in these samples.

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.

Synthesis, Characterization and Thermodecomposition Kinetics of Terbium(Ⅲ) Complex with Novel Schiff Base Salicylaldehyde-Taurine and 1,10-Phenanthroline

A complex of terbium(Ⅲ) with Schiff base salicylaldehyde-taurine and 1,10-phenanthroline was synthesized. The molecular formula was [Tb (sal-taurine) (1,10-phen) (NO_3)]·2H_2O (sal=salicylaldehyde, 1,10-phen=1,10-phenanthroline). The composition of the title complex was determined by elemental analysis and EDTA volumetic analysis. IR, Molar conductivity and X-ray powder diffraction were performed for its characterizations. The thermal decomposition kinetics of the complex were investigated under non-isothermal condition using the Achar differential method and the Coats-Redfern integral method. The kinetic equation for the second step corresponds to the mechanisms of the Zhuralev, Lesokin and Templman equation were obtained.

Microcalorimetric Character of Inhibition of Salicylaldehyde Glucosamine Schiff Base SG on Bacterial Metabolism

The power time curves of the reaction of E.coli with SG at different temperatures were determined by microcalorimetric method and the mutliplication rate constant k , generation time G , ratio I , and thermogenetic quantity Q , Q 0 and 0 were calculated.The function formulas have been established. It was found that P max , t g, t and 0 can be used to characterize the bacterial growth metabolism of E.coli and the antibacterial activity of SG.

Microwave Preparation and Spectroscopic Investigation of Binuclear Schiff Base Metal Complexes Derived from 2,6-Diaminopyridine with Salicylaldehyde

The binuclear Schiff base complexes prepared by condensation 2,6-diamino-pyridine and salicylaldehyde (LH) by using microwave and adding metal salts to ligand by same ratio. The Schiff base ligand was checked by infrared, electronic spectra and 1HNMR spectroscopy and prepared complexes characterized by molar conductivity, infrared, electronic spectra and susceptibility measurements. The values of molar conductivities reveal that the complexes are non-electrolytes, from obtained data of electronic spectra and magnetic moment, an octahedral geometry was suggested, coordinated to the metal ions in a manner with N donor sites of imine groups, and oxygen of phenolic OH group.

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.

Effect of butanol on flotation separation of quartz from hematite with N-dodecyl ethylenediamine

In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.

Ultrasonic-assisted condensation of chitosan with salicylaldehyde

In order to synthesize an improved adsorbent for heavy metal ions,we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base.The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods.The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical.The reaction conditions,including solvents,ultrasonic power density and irradiation time,pH,and reactant ratio,were optimized by orthogonal design.A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method.A condensation degree of 89.63% was achieved using the optimized conditions:i.e.ultrasonic irradiation at 180 W for 60 min;95% ethanol as the solvent,pH 4.0,and salicylaldehyde:chitosan ratio of 6:1.

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.

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.

Crystal Structures of O－Vanillin－semicarbazide and Salicylaldehyde－semicarbazide

o-Vanillin-semicarbazide C_9H_(11) N_3O_3, written simply as cpl, M_r= 209. 21 is a yellow crystal. Cp1 crystallizes in the monoclinic space group P2_1/a with unit cell parameters: a= 6. 596(6) , b=20. 534(6) , c=7. 108(6) , β=99.00(8)°,Z=4, D_c=1. 46 g/cm￣3, V=951 , μ=1. 05cm￣(-1), F(000)=440, R=0. 058, R_w =0. 056. Salicylaldehyde-semicarbazide C_8H_9N_3O_2, written simply as cp2, M_r=179.18 is a colorless crystal. cp2 crystallizes in the triclinic space group P1 with a= 5.276 (3), b=7. 116(4) , c=24. 286(3), a=86. 72(3) ,β=83. 99(3),γ=68.22(5) °,Z=4 , D_c=1. 41 g/cm￣3, V=841.9,μ=0. 98 cm ￣(-1),F (000)=376, R=0.066,R_w= 0. 067. The dihedral angle between plane 1 formed by benzene ring and plane 2 by N(2) , C(2), N(3), and O(3) is 161.40°for cp1, while the angle between plane 3 made by benzene ring (or benzene ring in the other molecule)and plane 4 by N(2) , C (18) , N(3) and O(3) For N(5),C(28) , O(4) , and N(6)]is 15. 07°(or 15. 15°) for cp2. The temperature of the thermodecomposition of cp1 is higher than that of cp2.

Thermodynamics of solubility of Cu_2(OH)_2CO_3 in ammonia-ammonium chloride-ethylenediamine(En)-water system

In order to decrease the evaporating rate of ammonia and increase the solubility of copper in the solution,ethylenediamine was added into the ammonia-ammonium chloride system to leach the copper-containing oxide ores.The thermodynamic model was constructed and the solubility of malachite Cu2(OH)2CO3 in the ammonia-ammonium chloride-ethylenediamine(En)-water system was calculated using the exponential computation method based on both mass balance and charge balance.It is found that the solubility of copper can be increased and the free ammonia concentration can be decreased by submitting partial ammonia with ethylenediamine.The lower free ammonia concentration in the solution is a guarantee to the lower evaporating rate of ammonia.The conditions of malachite Cu2(OH)2CO3 converting to atacamite Cu(OH)1.5Cl0.5 were also studied.A group of experiments were designed to validate the veracity of the results of the thermodynamic calculation.It is found that the thermodynamic model is reliable and it can guide the leaching process.

Selectively leaching Cu(Ⅱ) and Ni(Ⅱ) from acid mine drainage sludge by using ethylenediamine-ammonium sulfate

A method based on controlling the complexation precipitation equilibrium of metal ions was proposed to selectively recover nickel and copper from hydroxide sludge formed by lime neutralization of acid mine drainage(AMD). Ethylenediamine(EDA) and ammonium sulfate were chosen as complex reagent and precipitating reagent, respectively, to dissolve target metal hydroxides from sludge and limit useless metal ions in the pregnant solution. Results from both synthetic and natural samples show the excellent selectivity for the target metals(copper and nickel) against Fe(Ⅲ), Ca(Ⅱ) and Mg(Ⅱ), 99% recovery of Cu(Ⅱ) and Ni(Ⅱ) and shorter leaching time can be reached by this process, and the resultant solution can be used for direct electrowinning. The optimum operating conditions are: pH=9～11, ρ (EDA)=40 g/L, ammonium sulfate 50 g/L, leaching time 5 h(for natural sample) and 2.5 h(for synthetic sludge), liquid to solid ratio being 4 with mechanical stirring at room temperature.

Optical Properties, Electronic Energy Level Structure and Electroluminescent Characteristics of Salicylaldehyde Anil Zinc

A new electroluminescent material, salicylaldehyde anil zinc （SAZ） was synthesized, which can form high quality, thermal stability, nano-scale amorphous films by vacuum evaporation. Its structure, thermal stability were characterized by infrared （IR） spectra, differential thermal analysis-thermogravimetry （DTA-TG） analysis, respectively. The optical properties of SAZ were investigated by UV absorption spectra, Photoluminescence （PL） excitation and emission spectra. The highest occupied molecular orbits （HOMO）, lowest unoccupied molecular orbits （LUMO） and optical band gap were evaluated by cyclic voltammetry curve and optical absorption band edge. The electroluminescent devices using SAZ as the emissive layer emit green light with a peak wavelength at 509 nm and a brightness of about 3.1 cd/m^2.

Synthesis, Characterization, Thermal Decomposition Mechanism and Non-Isothermal Kinetics of Salicylaldehyde Salicylhydrazone and Its Complex of Erbium(Ⅲ)

The salicylaldehyde salicylhydrazone and its complex of Er(Ⅲ) were synthesized. The formulae K·4H_2O(HL=[C_(14)H_(10)N_2O_3]^(2-), the bivalent form of the salicylaldehyde salicylhydrazone) were determined by elemental analysis and EDTA volumetric analysis. Molar conductance, IR, UV and X-ray power diffraction were carried out for the characterizations of the complex and the ligand. There are two stable five-numbered and six-numbered circles in the complex. The thermal decompositions of the ligand and the complex with the kinetic study are carried out by non-isothermal thermogravimetry. The stages of the decompositions were identified by TG-DTG curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by the corresponding kinetic parameters.The activation energy value of the main step decomposition are also calculated by Kissinger′s method and Ozawa′s method.

Synthesis and spectral studies of macrocyclic Pb(Ⅱ),Zn(Ⅱ),Cd(Ⅱ)and La(Ⅲ) complexes derived from 1,4-bis(3-aminopropoxy)butane with metal nitrate and salicylaldehyde derivatives

Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis（3-aminopropoxy）butane with metal nitrate and 1,3-bis（2-formylphenyl）propane or 1,4-bis（2-formylphenyl）butane and their structures were proposed on the basis of elemental analysis, FTIR, UV-vis, molar conductivity measurements, ^1H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1： 1. The complexes are 1：2 electrolytes for Pb（II）, Zn（II） and Cd（II） complexes and 1：3 electrolytes for La（III） as shown by their molar conductivities （Am） in DMSO at 10^-3 mol L^-1. Due to the existence of free ions in these complexes, such complexes are electrically conductive. The configurations of La（III） and Pb（II） were proposed to probably octahedral and Zn（II） and Cd（II） complexes were proposed to probably tetrahedral.

A Novel Potassium Complex Based on the Taurine-salicylaldehyde Schiff Base:Synthesis,Crystal Structure and Spectroscopy

A novel two-dimensional self-assembly network formulated as [K（TSSB）]n （TSSB= taurine-salicylaldehyde Schiff base） has been synthesized via the reaction of salicylaldehyde with taurine at the presence of potassium hydroxide in water-methanol solution,and was structurally characterized by elemental analysis,IR,UV-VIS spectra and X-ray diffraction.It crystallizes in the monoclinic system,space group P21/c with a=20.245（3）,b=7.2905（9）,c=7.5458（10）,β= 94.1920（10）o,V=1110.8（2）3,Mr=267.34,Z=4,Dc=1.599 g/cm3,μ（MoKα）=0.663 mm-1 and F（000）=552.The units of K[TSSB] are linked into a one-dimensional double chain structure via the sulfonic groups from the taurine-salicylaldelyde Schiff base,and such chains are further extended through O-K-O bond interactions resulting in a two-dimensional supramolecular architecture.In the complex,the K（I） ion displays a slightly distorted dodecahedral geometry with an eight-coordination number.