碘化钾 正丙醇 锗三元缔合物萃取分离锗

探讨了碘化钾 正丙醇 锗三元缔合物萃取分离锗的行为及与一些金属离子分离的条件。结果表明, 氯化钠能将正丙醇的水溶液分成两相,在分相过程中,Ge与碘化钾生成的GeI62-与质子化正丙醇(C3H7OH2+)形成的缔合物［GeI62-］［C3H7OH2+］2能被正丙醇相完全萃取。当正丙醇、碘化钾和氯化钠的浓度分别为30%（V/V)、80×10-3 mol/L、020 g/mL时, Ge的萃取率达到984%以上,Zn2+、Fe2+、Mg2+、Ni2+、Co2+、Mn2+、Ag+、Al3+和Cr3+基本不被萃取,实现了Ge与上述金属离子的分离。     

Thermodynamic aspects of the selection of sulfur-containing collectors during flotation of sulfide ores

Investigations into the complexing ability of sulfur-containing collectors relative to metal ions (Cu²⁺, Ni²⁺, Fe²⁺, Co²⁺) at 298 K and an ion force of 0.075–0.75 mol/L (NaNO₃) are carried out. It is established that potassium dibutyl dithiophosphate possesses the largest affinity to metal ions among phosphorus-containing collectors, while the maximal complexing ability is characteristic of the Co²⁺ ion. Series of thermal stability are found; the variations in enthalpy, entropy, and the Gibbs energy, as well as temperature-dependent and temperature-independent contributions of complexes of metal ions with collector anions into ΔG ⁰, are calculated.     

Formation and recovery of Co,Ni, Cu macromolecular complexes with polystyrene and acrylic acid

The formation and structure of Co²⁺, Ni²⁺ and Cu²⁺ macromolecular complexes with a series of polystyrene and acrylic acid copolymers (PSt/AA) were studied. Both the copolymers and the metal complexes (M-PSt/AA) were characterized by FTIR, elemental analysis, Gel Permeation Chromatography and AAS. It is shown that the PSt/AA copolymer has rather strong coordination ability to the metal ions by chelation with the carboxylate group, and the microstructures of the M-PSt/AA complexes can be well controlled. Its adsorption behavior toward Co²⁺, Ni²⁺ or Cu²⁺ and various related parameters in the separation process were determined. The results indicate that the adsorption capability varies with pH and the maximum adsorption capacities were 337 mg/g for Co²⁺, 338 mg/g for Ni²⁺ and 341 mg/g for Cu²⁺ at around pH 7. Adsorption isotherms reveal that the adsorption process is consistent with the Freundlich equation. Experiments show that PSt/AA can recover Co²⁺, Ni²⁺ or Cu²⁺ with a high adsorption rate and high selectively coefficient from a simulated industry solution containing Ca²⁺ and Mg²⁺ as impurities. The resin can be readily stripped with acid and recycled for re-use after transformation to its sodium form.     

Solubility and activity of oxygen in liquid germanium and germanium-copper alloys

The solubility of oxygen in liquid germanium in the temperature range 1233 to 1397 K, and in liquid germanium-copper alloys at 1373 K, in equilibrium with GeO₂ has been measured by the phase equilibration technique. The solubility of oxygen in pure germanium is given by the relation log(at. pct 0)=-6470/T + 4.24 (±0.07). The standard free energy of solution of oxygen in liquid germanium is calculated from the saturation solubility, and recently measured values for the free energy of formation of GeO₂, assuming that oxygen obeys Sievert’s law up to the saturation limit. For the reaction, 1/2 O₂(g)→O_Ge ΔG° = -39,000 + 3.21T (±500) cal = -163,200 + 13.43T (±2100) J. where the standard state for dissolved oxygen is that which makes the value of activity equal to the concentration (in at. pct), in the limit, as concentration approaches zero. The effect of copper on the activity of oxygen dissolved in liquid germanium is found to be in good agreement with that predicted by a quasichemical model in which each oxygen was assumed to be bonded to four metal atoms and the nearest neighbor metal atoms to an oxygen atom are assumed to lose approximately half of their metallic bonds. On leave at the Department of Metallurgy and Materials Science, University of Toronto, when this investigation was undertaken.     

Solubility and activity of oxygen in liquid germanium and germanium-copper alloys

The solubility of oxygen in liquid germanium in the temperature range 1233 to 1397 K, and in liquid germanium-copper alloys at 1373 K, in equilibrium with GeO2 has been measured by the phase equilibration technique. The solubility of oxygen in pure germanium is given by the relation R470 log(at. pct 0)=-6470/T+4.24 (±0.07). The standard free energy of solution of oxygen in liquid germanium is calculated from the saturation solubility, and recently measured values for the free energy of formation of GeO₂, assuming that oxygen obeys Sievert’s law up to the saturation limit. For the reaction, 1/2 O₂(g)→ OGe ΔG° =-39,000 + 3.21T (±500) cal = -163,200 + 13.43T (±2100) J. where the standard state for dissolved oxygen is that which makes the value of activity equal to the concentration (in at. pct), in the limit, as concentration approaches zero. The effect of copper on the activity of oxygen dissolved in liquid germanium is found to be in good agreement with that predicted by a quasichemical model in which each oxygen was assumed to be bonded to four metal atoms and the nearest neighbor metal atoms to an oxygen atom are assumed to lose approximately half of their metallic bonds. K. FITZNER was on leave at the Department of Metallurgy and Materials Science, University of Toronto, when this investigation was undertaken.     

Some ion exchange properties of exfoliated vermiculite

Exfoliated vermiculite was used as an ion exchange medium for the removal of transition metal ions from dilute aqueous solutions. Two different grades of a commercial exfoliated vermiculite were employed.Ion exchange was effected by continuous flow through a packed column. A simple favourable-equilibrium model for the breakthrough curve was found to fit the data provided the flow rate was less than 1.5 ml/cm² min. Diffusion coefficients for the ions in the vermiculite were estimated from the model to be of the order of 10^?9 cm² sec^?1.The times taken to breakthrough were in the order Ni²⁺ > Cu²⁺ > Zn²⁺ > Cr³⁺. It was found that the breakthrough time of the smaller vermiculite particles was considerably greater than that of the larger particle size.Total cation exchange capacities were determined by batch equilibration. Those of nickel and zinc were of the order of 1 meq/g, whilst those of copper and chromium were of the order of 2 meq/g. These values are of the same magnitude as those found in the literature for similar ions.     

Extraction of metals using poly[N-(dithiocarboxylato)-iminoethenehydrogenoiminioethene]

The polymer poly [N- (dithiocarboxylato)iminoethenehydrogenoiminioethene] (PIED) reacts with metal ions such as iron, cobalt, nickel, copper, zinc and silver to produce stable compounds in which the metal is co-ordinated to the sulphur atoms in the dithiocarboxylate groups. The capacity of the polymer PIED for a particular metal is a function of the sulphur content, pH, complexing agents, and other metals which are present in solution. The polymer rapidly takes up the metals (e.g. Co²⁺ at pH 6.5 has a $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of one and a half minutes). The polymer is stable between pH values of 6.5 and 9.0 but rapidly decomposes at low pH due to the protonation of the amino group adjacent to the dithiocarboxylate groups and the loss of carbon disulphide. The pK_a values of these amino groups is over the range 3.5 to 6.5. Above a pH of 10 the polymer dissolves but is reprecipitated on the addition of acid. The stable metal—polymer complexes can be used for metal extractions over a wide pH range e.g. cobalt(II)—PIED can be used to extract silver from a solution containing cobalt and silver. Consequently the metal salts are recommended for metal extraction. It is not possible to elute the metals using standard reagents such as cyanide but the cobalt—PIED is reduced by hydrogen at 1400 K to give cobalt metal although the polymer backbone is destroyed. The nickel(II)—PIED compound can be quantitatively oxidised to nickel(IV)—PIED which is stable in air and in which all of the nickel ions are oxidised to nickel(IV).     

硫酸铵-碘化钾-十二烷基三甲基氯化铵微晶吸附体系浮选分离镉(Ⅱ)

研究了硫酸铵-碘化钾-十二烷基三甲基氯化铵微晶吸附体系浮选分离镉(Ⅱ)的行为及其与常见离子定量分离的条件。结果表明,在0.5 g (NH₄)₂SO₄的存在下,当体系中Cd²⁺、KI、DTMAC同时存在时,体系中形成的三元缔合物(DTMAC)₂(CdI₄) 沉淀被定量吸附在DTMAC ⁺·I^-微晶物质表面而被浮选至盐水相上,Cd²⁺被定量浮选,Co²⁺、Ni²⁺、Zn²⁺、Mn²⁺、Fe³⁺、Al³⁺等离子留在水相中而不被浮选,实现了Cd²⁺与这些离子的定量分离,据此建立了一种微晶吸附体系浮选分离Cd²⁺的新方法。通过扫描电镜图片确证了DTMAC ⁺·I^-微晶物质的产生,探讨了Cd²⁺的浮选分离机理。方法成功用于合成水样中Cd²⁺的定量浮选分离,浮选率为95.4%～105.3%。     

Structural and electronic properties of bastnaesite and implications for surface reactions in flotation

The structural and electronic properties of bastnaesite were studied by using the first-principles method based on the density functional theory(DFT).The geometry structure of bastnaesite was first optimized,and then the Mulliken populations,electron density and density of states were calculated and further analyzed in detail.The calculation results reveal that it mainly ruptures along the ionic Ce-O and Ce-F bonds during the cleavage of bastnaesite,leaving≡Ce~+,≡F~-and≡CO_3~-dangling bonds exposed on the cleavage surface of bastnaesite.Combined with contact angle measurement,surface complexation theory and XPS analysis,the implications of structural and electronic properties on bastnaesite flotation reactions were studied.The hydration of exposed strong ionic bond on cleavage surface results in hydrophilic surface.According to surface complexation theory,the formed surface groups are≡CeOH~0,≡CO_3 H~0 and≡FH~0 groups.The investigated metal ions and flotation reagents complex with surface≡CeOH~0 groups,while≡CO_3 H~0 and≡FH~0 groups are not involved in the complexation.The high activity of Ce atoms facilitates these surface reactions.     

Effects of Calcium and Chloride Ions in Iron Ore Reverse Cationic Flotation: Fundamental Studies

ABSTRACT

In this work, the simultaneous effects of Ca²⁺ and Cl^? ions in an aqueous solution at pH 10.5 on the flotation of quartz (the main impurity in itabiritic iron ore) and hematite by starch and amine was investigated. A strong depression in the flotation of both quartz and hematite conditioned with CaCl₂ was observed. This effect was higher for hematite than for quartz. Based on zeta potential measurements and the speciation diagram of calcium in aqueous solutions, the physical adsorption of Ca²⁺ on the surfaces of both minerals was inferred. The infrared spectrum of quartz conditioned with CaCl₂ at pH 10.5 was similar to its reagent-free reference spectrum. However, a new band at the wavenumber of 1465 cm^?1 was identified in the spectrum of hematite conditioned with CaCl₂; this band did not exist in its reference spectrum. This new band may indicate the chemical adsorption of Cl^? ions on the hematite surface. The complexation of Ca²⁺ by ethylenediaminetetraacetic acid enabled complete quartz recovery with amine. For hematite, recovery was partially restored, probably because of the positive chloro-complexes on the hydrated iron surfaces of hematite, which prevented the adsorption of aminium ions at these sites. Therefore, the selective inverse cationic flotation of itabiritic iron ore at pH 10.5 in water containing Ca²⁺ is possibly only after complexing them with EDTA.     

Anion/Cation(H2PO4- and Fe3+)induced dual luminescence quenching effect based on terbium solid sensor

An investigation on the photophysical properties of the newly designed terbium imidazole-4,5-dicarboxylic acid complex encapsulated in the inert matrices(tetraethoxysilane,TEOS)was performed.The composite material was very stable and showed strong green emission in pure water.Interestingly,we discovered that the luminescence of hybrid material was selectively responsive to H2PO4-.1H-NMR and fluorescence spectra supported that the receptor had strong affinity to dihydrogen phosphate.Meanwhile,the luminescence was quenched by Fe3+ when adding different metal ions such as Fe3+,Pd2+,Cd2+,Co2+ and Mn2+ concomitantly.Moreover,thin film was successfully prepared by the same materials and it also exhibited selective recognition behavior to the above two ions.     

Formation of complex compounds of univalent copper at the Cu<Superscript>0</Superscript>-Cu<Superscript>2+</Superscript> interphase boundary in chloride solutions

Kinetics and a mechanism of formation of compounds of univalent copper at the interphase boundary Cu⁰-Cu²⁺ in the solution containing excess chlorine anions are investigated by the spectrophotometry method. It is shown that the [CuCl₂]^? and [CuCl₃]^2? complex anions are formed during the contact of metal copper with the Cu²⁺ ions. The former ones are characterized by the appearance of the band in the region of 233 nm in the spectra of electron absorption, and the latters ones—in the region of 273 nm. The dependence of intensity of absorption bands on the contact time of the Cu²⁺ ions with copper is used to estimate the kinetic parameters of formation and oxidation of the [CuCl₂]^? and [CuCl₃]^2? ions. A thickness of the reaction layer, in which they are formed, is determined. The formation of the Cu(I) compounds during the contact interaction of copper with the Cu²⁺ ions is confirmed by the results of electrochemical investigations. The mechanism of cathode reduction of copper-containing compounds on a copper electrode is suggested.     

Comparative study of dewatering characteristics of metal precipitates generated during treatment of monometallic solutions

The sludge dewatering properties (settling, filtration and centrifugation) of metal precipitates generated during treatment of monometallic solutions (0.020 mol/L) have been evaluated in this research. The precipitation tests carried out on 15 different metals gave metal removal yields generally similar to those predicted by MINEQL+ software, with the exception that kinetic aspects should be considered during precipitation of metal sulphides and phosphates. Hydroxides precipitation at pH 10.0 was the most efficient technique for the removal of eight metallic ions (Al³⁺, Cd²⁺, Co²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Mn²⁺, Ni²⁺), whereas phosphates precipitation (at pH 6.0 with an addition of 0.0133 mol PO₄^3?/L) gave highest removal yields for Ba²⁺, Ca²⁺, Cr³⁺. Sulphides precipitation (at pH 7.0 and using, 0.020 mol S^2?/L) has been found the most efficient technique only for Cu²⁺ and Sn²⁺ precipitation, whereas carbonates precipitation (at pH 8.0 and using 0.020 mol CO₃^2?/L) gave better removal yield only for Pb²⁺. Results have also shown that metal phosphates have generally better dewatering characteristics (SVI, filtration capacity, SRF, sludge solids content) than metal carbonates, sulphides and hydroxides. In fact, considering only the sludge dewatering characteristics, phosphates precipitation appears the most appropriate technique for the precipitation of many metals (Al³⁺, Ba²⁺, Cd²⁺, Co²⁺, Cr³⁺, Fe²⁺, Fe³⁺, Ni²⁺ and Zn²⁺). Metal hydroxides formation constitutes the best option for Ca²⁺, Cu²⁺, Mg²⁺ and Sn²⁺ removal, whereas precipitation of metal carbonates is particularly interesting for treatment of Mn²⁺ and Pb²⁺ containing solutions.     

Energy transfer from Tb3+ to Eu3+ in zinc lead borate glass

In order to sensitize the luminescence of Eu³⁺ ions in heavy metal glass, zinc lead borate glass samples containing various concentrations of Eu³⁺ and Tb³⁺ ions were prepared to study the Tb³⁺ to Eu³⁺ non-radiative energy transfer phenomena. Energy level structures of Tb³⁺ and Eu³⁺ ions were plotted to show the excitation and energy transfer routes. Efficient energy transfer from Tb³⁺ to Eu³⁺ was observed and studied qualitatively in terms of doping concentrations. The sensitization turned out to be less effective than expected. Further studies to characterize the oxidation of Tb³⁺ into tetravalent state and to examine the mechanism of energy transfer are proposed.     

Complexes of carboxymethylcellulose in water. Part 2. Co2+ and Al3+ remediation studies of wastewaters with Co2+, Al3+, Cu2+, VO2+ and Mo6+

The properties of carboxymethylcellulose (CMC) complexes and Co²⁺ and Al³⁺ are reported in this work. The complexing power of CMC was greater to Al³⁺ than to Co²⁺, although it was not possible to determine some of the equilibrium constants. The infrared (IR) spectroscopy and thermal analysis helped in showing the existence of these complexes in the solid state. The films observed by scanning electron microscopy (SEM) provided a certainty that the chains of the biopolymer were not extensively broken by the use of strong mineral acid employed in some of the experimental steps of this study.Two water solutions — bidistilled and deionized water and an Iraí River, Curitiba, PR (Brazil) sample — were obtained by adding metal salts of Al³⁺, Co²⁺, Cu²⁺, Mo⁶⁺(initially in the form of molybdate) and VO²⁺ to which CMC was later added as a remediation agent. At different times, aliquots of those water samples were analyzed for their metal contents and showed ability to sequester different percentages of each of the metal ions, therefore, rendering the water samples within the Brazilian and Spanish standards for potable water (varying from < 0.3 to 5 mg/L depending on toxicity). The CMC complexes could be recovered by mechanical removal at the pH where these complexes are not very soluble. This process can be applied to municipal wasterwater treatment plants as CMC is a more cost-effective and non toxic alternative material than commercial employed alum. The metals can be recycled after the decomplexing process from the recovered solid complexes and with the additional benefit of using CMC that it will leave no trace of Al³⁺ ions in the water rising from the use of alum.     

The electrical conductivity of some liquids in the system CaF2+CaO+Al2O3

The conductivity of slags in the binary systems CaF₂+Al₂O₃, CaF₂+CaO and the ternary system CaF₂+CaO+Al₂O₃ has been measured, using a four-lead electrode technique at a frequency of 1 kHz. The cell design used ensured that only molybdenum metal was in contact with the slag at high temperature and that the slag was wholly contained in molybdenum. No frequency dispersion could be detected at frequencies between 0.8 to 10 kHz. It is suggested that the formation of complex ions (e.g. AlO₂F₂ ³⁻ and AlOF ₂ ⁻ ) might account for the observed effects in CaF₂+Al₂O₃, CaF₂+CaO+Al₂O₃ liquids as has been previously suggested. an oxide ion clustering mechanism may explain the conductivities found in CaF₂+CaO.     

Sorption technology of recovery of indium from solutions of zinc production

Sorption of indium ions from polycomponent solutions with preliminarily reduced iron(III), which contain, g/dm³, 0.084 In³⁺, 6.2 Fe²⁺, 67.0 Zn²⁺, and 19.6 H₂SO₄, on the Metosol reagent, is investigated in the dynamic mode. The Metosol reagent represents montmorillonite of composition (Na,Ca)_0.3(Al,Mg)₂Si₄O₁₀(OH)₂(H₂O) _n , modified with di(2-ethylhexyl)phosphoric acid. The absorption dynamics of ions by it is investigated by frontal chromatography. The values of working (DEC) and total (CDEC) dynamic exchange capacities of the mineral sorbent are determined depending on the eluent specific passing rate and temperature. The main parameters of the sorption technology of the selective recovery of indium from process solutions of the zinc production on the Metosol reagent in columns followed by the desorption of metal with the hydrochloric acid solution (1: 1) are substantiated and calculated.     

氢化物发生-原子荧光光谱法测定处理废水中砷

研究了氢化物发生-原子荧光光谱法测定砷钙渣固化、高砷烟尘湿法中和、苄基砷酸及仲钨酸铵生产等废水中砷的最佳条件。实验表明,废水样经化学处理,在稀盐酸介质中用硫脲-抗坏血酸将砷预还原为砷,Fe³⁺、Ca²⁺、Na⁺、Cu²⁺、F^-、S^2-、Bi³⁺、Sn⁴⁺、Sb⁵⁺等23 种离子的允许量（mg/50 mL）中高者达250或低至0.5。载液盐酸浓度为5%（V/V）,定量样品与15 g/L硼氢化钾碱性溶液混合生成砷化氢。在选定条件下, 砷量在 2～100 μg/L范围内线性关系良好,检出限（3σ/K）为0.001 4 μg/L。方法用于实际废水样品分析, 相对标准偏差（n=9～11）为1.6%～5.9%,加标回收率在93%～118%之间,固化废水测定值与砷锑钼蓝光度法相符。     

Leaching kinetics of ionic rare-earth in ammonia-nitrogen wastewater system added with impurity inhibitors

Ammonia-nitrogen wastewater is produced during the dressing and smelting process of rare-earth ores.Such wastewater includes a very high concentration of NH4＋, as well as other ions（e.g., NH4＋, RE3＋, Al3＋, Fe3＋, Ca2＋, Cl–, and Si O32–） with a p H of 5.4–5.6.Its direct discharge will pollute, yet it can be recycled and used as a leaching reagent for ionic rare-earth ores.In this study, leaching kinetics studies of both rare earth ions and impurity ion Al3＋ were conducted in the ammonia-nitrogen wastewater system with the aid of impurity inhibitors.Results showed that the leaching process of rare-earth followed the internal diffusion kinetic model.When the temperature was 298 K and the concentration of NH4＋ was 0.3 mol/L, the leaching reaction rate constant of ionic rare-earth was 1.72 and the apparent activation energy was 9.619 k J/mol.The leaching rate was higher than that of conventional leaching system with ammonium sulfate, which indicated that ammonia-nitrogen wastewater system and the addition of impurity inhibitors could promote ionic rare-earth leaching.The leaching kinetic process of impurity Al3＋ did not follow either internal diffusion kinetic model or chemical reaction control, but the hybrid control model which was affected by a number of process factors.Thus, during the industrial production the leaching of impurity ions could be reduced by increasing the concentration of impurity inhibitors, reducing the leaching temperature to a proper range, accelerating the seepage velocity of leaching solution, or increasing the leaching rate of rare earths.     

Separation and recovery of palladium(II) from base metal ions by melamine–formaldehyde–thiourea (MFT) chelating resin

Melamine–formaldehyde–thiourea (MFT) resin, a chelating resin, was synthesized by reaction with melamine, formaldehyde and thiourea in aqueous solution. This chelating resin was used in the separation and recovery of palladium(II) from copper(II) and zinc(II) base metal ions. Effect of initial acidity, adsorption capacities of the metal ions by batch method and adsorption, elution, separation factors and column adsorption capacity of the metal ions by column method were examined. The optimum initial acidity was determined as pH 4. Adsorption capacities of the MFT resin were found as 15.29 mg/g (0.144 mmol/g) for palladium(II), as 1.612 mg/g (0.025 mmol/g) for copper(II) and as 0.453 mg/g (0.007 mmol/g) for zinc(II). In addition the protonation capacity of the resin was found as 0.110 mmol H⁺/g. It was concluded that ionic interaction between protonated amines on the resin and chloro-palladate complex (PdCl₄^2?) was very effective as well as chelation. In the column studies, dynamic adsorption capacities were calculated as 1580 μg/g (14.85 μmol/g) for palladium(II), as 250 μg/g (3.93 μmol/g) for copper(II) and as 25 μg/g (0.38 μmol/g) for zinc(II). MFT resin showed higher affinity to palladium(II) ions according to copper(II) and zinc(II) ions. It was seen that palladium(II) can be separated from copper(II) and zinc(II) and concentrated by melamine–formaldehyde–thiourea chelating resin.