锌精矿氧压酸浸液中铟的提取研究

对锌精矿氧压酸浸液中铟的提取进行了研究,在1.0m o l/L的H2SO4介质中,铟可被P204定量萃取,当萃取相比为O/A=1/4,进行三级萃取,平衡时间为3m in时,In萃取率达97%以上;对负载有机相用3m o l/L的HC l进行三级反萃,O/A=5/1,平衡时间为3m in,In反萃率为99.62%。     

Adsorption phenomena in hydrometallurgy, 1 The uptake of copper,nickel and cobalt by oxide adsorbents in aqueous ammoniacal solutions

The uptake or adsorption of copper, nickel and cobalt by finely divided oxide solids in aqueous ammoniacal medium has been investigated experimentally in order to determine how adsorption on leach residues can affect the recovery of leachable metals. Hematite, rutile, alumina and quartz were used as model solid adsorbents. In the case of ammoniacal leach solutions the controlling metal species appears to be the aqueous neutral hydroxo species. Adsorption behavior was found to have maxima and minima as a function of pH, the magnitude of which depends on ammonia concentration, the metal cation, and the adsorbent.     

High pressure equilibrium of nickel and cobalt between metal and mantle minerals

In order to test the effect of very high pressures on the siderophile behaviour of two elements, Ni and Co, we have carried out diamond anvil cell experiments on Ni- and Co-bearing systems, up to 70 GPa. Observation of recovered samples by analytical transmission electron microscopy shows that Ni and Co remain siderophile at least up to 70 GPa, but that their siderophile character decreases with pressure, as already observed in previous studies at lower pressures. Our results also suggest that the abundances of Ni and Co observed in the Earth’s upper mantle cannot be explained by very high pressure equilibrium between silicate perovskite, magnesiowüstite, and metal.     

铜镍尾矿砂微波加热硫酸溶解实验研究

通过尾矿砂微波加热硫酸溶解新方法的实验,研究了硫酸浓度、液固比及反应时间等因素对尾矿砂酸蚀率的影响。结果显示,在无需搅拌的情况下,微波加热实验的最佳条件酸浓度5mol/L、液固比5.0mL/g都较传统水热法有优势,在反应时间上,微波加热15min就能达到传统水热法2～3h的效果。在酸蚀率相同的情况下,微波加热所用时间仅为传统水热法的1/6,而所用的酸浓度、液固比都较传统水热法小很多。先对尾矿砂直接微波辐照一段时间,然后再加入硫酸进行微波辐照加热溶解,能够促进尾矿砂的溶解,提高尾矿砂的酸蚀率。微波加热条件下,尾矿砂在硫酸浓度8mol/L、液固比5.0mL/g条件下无需搅拌,反应1h后,除透闪石没有完全溶解外,绝大部分的矿物被溶解。与传统加热方式相比,微波加热可显著提高尾矿砂酸溶解速率。     

金川铜镍矿山尾矿砂酸溶性实验研究

为研究金川铜镍矿山酸性废水溶解尾矿砂实现综合治理废液与废固的可能性,进行了尾矿砂在硫酸中的溶解实验。结果表明,尾矿砂在硫酸浓度大于3mol/L、温度保持90℃以上并在液固比6.0下强力搅拌,能够较好地溶解于硫酸中,生成无定形二氧化硅;300℃的马弗炉焙烧4h有助于尾矿砂中绿泥石的溶解,对透闪石的溶解影响不大。尾矿砂中橄榄石、蛇纹石和透辉石较容易被硫酸溶解,透闪石、斜长石则比较难溶解,这与尾矿砂中矿物性质有密切关系。     

Silver losses from ammoniacal solutions on complex sulphide and chalcopyrite ammonia leach residues

Extraction and subsequent loss of silver from leach liquor during oxidative ammonia leaching of complex sulphide and chalcopyrite concentrates have been observed. The lost silver value from the leach liquor was unrecoverable when the residues were treated with ammonia-ammonium sulphate buffer (pH=9.5) solutions at 27°C. However, when the same slurry was heated to 75°C in an autoclave under an atmosphere of oxygen, almost all the silver value could be redissolved. The leach residues lost their silver absorbance property from ammoniacal solutions on repeatedly heating and cooling the leached slurries in the presence of oxygen. In this work, silver losses from ammoniacal solutions on various leach residues, synthetic iron oxides, and freshly precipitated Fe(II) and Fe(III) hydroxides are reported. None of the major constituents present in the leach residues were responsible for the silver losses but small amounts of Fe(II) associated with the residues could take up silver from the leach solutions.     

Dissolution kinetics of soil clays in sulfuric acid solutions: Ionic strength and temperature effects

Significant amounts of sulfuric acid (H₂SO₄) rich saline water can be produced by the oxidation of sulfide minerals contained in inland acid sulfate soils (IASS). In the absence of carbonate minerals, the dissolution of phyllosilicate minerals is one of very few processes that can provide long-term acid neutralisation. It is therefore important to understand the acid dissolution behavior of naturally occurring clay minerals from IASS under saline–acidic solutions. The objective of this study was to investigate the dissolution of a natural clay-rich sample under saline–acidic conditions (pH 1–4; ionic strengths = 0.01 and 0.25 M; 25 °C) and over a range of temperatures (25–45 °C; pH 1 and pH 4). The clay-rich sample referred to as Bottle Bend clay (BB clay) used was from an IASS (Bottle Bend lagoon) in south-western New South Wales (Australia) and contained smectite (40%), illite (27%), kaolinite (26%) and quartz (6%). Acid dissolution of the BB clay was initially rapid, as indicated by the fast release of cations (Si, Al, K, Fe, Mg). Relatively higher Al (pH 4) and K (pH 2–4) release was obtained from BB clay dissolution in higher ionic strength solutions compared to the lower ionic strength solutions. The steady state dissolution rate (as determined from Si, Al and Fe release rates; R_Si, R_Al, R_Fe) increased with decreasing solution pH and increasing temperature. For example, the highest log R_Si value was obtained at pH 1 and 45 °C (−9.07 mol g⁻¹ s⁻¹), while the lowest log R_Si value was obtained at pH 4 and 25 °C (−11.20 mol g⁻¹ s⁻¹). A comparison of these results with pure mineral dissolution rates from the literature suggests that the BB clay dissolved at a much faster rate compared to the pure mineral samples. Apparent activation energies calculated for the clay sample varied over the range 76.6 kJ mol⁻¹ (pH 1) to 37.7 kJ mol⁻¹ (pH 4) which compare very well with the activation energy values for acidic dissolution of monomineralic samples e.g. montmorillonite from previous studies. The acid neutralisation capacity (ANC) of the clay sample was calculated from the release of all structural cations except Si (i.e. Al, Fe, K, Mg). According to these calculations an ANC of 1.11 kg H₂SO₄/tonne clay/day was provided by clay dissolution at pH 1 (I = 0.25 M, 25 °C) compared to an ANC of 0.21 kg H₂SO₄/tonne clay/day at pH 4 (I = 0.25 M, 25 °C). The highest ANC of 6.91 kg H₂SO₄/tonne clay/day was provided by clay dissolution at pH 1 and at 45 °C (I = 0.25 M), which is more than three times higher than the ANC provided under the similar solution conditions at 25 °C. In wetlands with little solid phase buffering available apart from clay minerals, it is imperative to consider the potential ANC provided by the dissolution of abundantly occurring phyllosilicate minerals in devising rehabilitation schemes.     

Segregation roasting of nickel,copper and cobalt from deep-sea manganese nodules

The recovery of nickel, copper and cobalt from ocean manganese nodules by a segregation roasting technique was investigated under a wide range of conditions with several nodule samples all of which gave similar results. The best conditions for the segregation of the metals were achieved with CaCl₂ as the chloride source at a batch retention time of approximately two hours; the highest recoveries were obtained at approximately 850°C for copper and at 1,050°C for nickel and cobalt. At 850°C, copper recovery was 75%, but nickel and cobalt recoveries were only about 25%. At 1,050°C, the nickel and cobalt recoveries were increased to about 60%, but the copper recovery dropped to only 35%. Electron-probe microanalysis showed the segregated metal to be an alloy, indicating that gaseous reactions play an important role in the reduction of chlorides to metal during the process.     

Crystal chemistry of cobalt and nickel in lithiophorite and asbolane from New Caledonia

The crystal chemistry of Ni- and Co-bearing manganese oxides (lithiophorite and asbolane) has been investigated by X-ray Absorption Spectroscopy (XAS). The Mn oxides come from the lateritic weathering profiles of the ultrabasites of New Caledonia. The distinct behaviours of Ni and Co concern both oxidation states and local structures.The electronic structure and short range order around Co atoms do not depend on the nature of the Cocontaining phase. Co atoms are trivalent and 6-fold coordinated. Co-(O, OH) and Co-(Co, Mn) interatomic distances derived from EXAFS are equal to those found around Mn atoms which rules out the possibility of an adsorption of Co atoms directly above and below vacancies of MnO₂ layers. The high structural order around Co contrasts with the structural disorder observed around Mn. Cobalt atoms do not occupy specific Mn sites and are not randomly distributed within the octahedral Mn layers.Unlike Co, Ni exhibits distinct surroundings in both phases. In asbolane, Ni atoms build partial Ni(OH)₂ layers. Ni-OH distances are lower as compared with the free Ni hydroxide because of the formation of hydrogen bonds between Ni(OH)₂ and MnO₂ layers. In lithiophorite Ni atoms are located in the hydrargillite layer (Al(OH)₃). Both chemical composition and structural considerations militate for a Ni for Li substitution in lithiophorite. Finally, evidence is given for the existence of a mixed-layering between lithiophorite and asbolane and the chemical variations generally observed in these Mn oxides are interpreted as a variable proportion of (Mn, Co)(O, OH₂, Ni(OH)₂ and (Al, Li, Ni)(OH)₃ layers.     

Removal of cadmium and humic acid from aqueous solutions using surface modified nanozeolite A

The sorption of cadmium and humic acids from aqueous solutions using surface-modified nanozeolite A has been investigated under various examination conditions. The morphology of untreated and treated nanozeolite was studied under scanning electron microscope and transmission electron microscope. Isotherms of cadmium adsorption onto surface-modified nanozeolite A were studied at different pH, solid to liquid ratio, adsorbate concentration and interaction time. Kinetic and equilibrium studies were conducted and the equilibrium data have been analyzed using Langmuir and Freundlich isotherm models. The study revealed that experimental results were in agreement with the Freundlich model. The Langmuir monolayer adsorption capacity was found to be 1666.67 g cadmium and 6.75 g humic acid per gram of modified nanozeolite A, which is higher than that of reported value for other zeolites. The sorption ability was enhanced by surface modification and reduction in size and enabled the zeolite to adsorb cadmium. The adsorption of cadmium and humic acid on nanozeolite was found to be the highest at pH 6 and 3, respectively. Results showed that solid to liquid ratio and pH are the most important factors for cadmium and humic acid removal, respectively. Effect of competitive ions was studied and results showed that there is no competition between cadmium and humic acid sorption and presence of these ions.     

Removal of chromium (VI) from aqueous solutions using Lewatit FO36 nano ion exchange resin

The removal of the chromium (VI) ion from aqueous solutions with the Lewatit FO36 ion-exchange resin is described at different conditions. The effects of adsorbent dose, initial metal concentration, contact time and pH on the removal of chromium (VI) were investigated. The batch ion exchange process was relatively fast and it reached equilibrium after about 90 min of contact. The ion exchange process, which is pH dependent showed maximum removal of chromium (VI) in the pH range 5.0–8.0 for an initial chromium (VI) concentration of 0.5 mg/dm³. The equilibrium related to Lewatit FO36 ion- exchange capacity and the amounts of the ion exchange were obtained using the plots of the Langmuir adsorption isotherm. It was observed that the maximum ion exchange capacity of 0.29 mmol of chromium (VLVg for Lewatit FO36 was achieved at optimum pH value of 6.0. The ion exchange of chromium (VI) on this cation-exchange resin followed first-order reversible kinetics.     

Vanadium,nickel and cobalt variations in eclogites from Roberts Victor Mine,South Africa

The V-Ni-Co variation trend of Roberts Victor eclogites is toward the enrichment of vanadium at the expense of nickel with relatively little change of cobalt. The systematic V-Ni-Co variation together with petrographic evidences suggest that Group I and Group II eclogites from Roberts Victor Mine were most probably formed by fractional crystallization.     

Adsorption phenomena in hydrometallurgy, 2. Electrophoretic behavior of oxides in aqueous ammoniacal solutions of copper,nickel and cobalt

The electrophoretic mobilities of finely divided oxides in aqueous ammoniacal solutions of copper, nickel, and cobalt have been measured. The solids used were rutile, alumina, quartz, and hematite. The effects of pH, ammonia-ammonium concentration, and metal-ion concentration on the electrophoretic behavior were investigated. The experimental results indicate that oxide colloids may undergo as may as five charge reversals in aqueous ammoniacal solutions of hydrolyzable ammine-forming metal ions.     

Speciation and solubility relationships of Al, Cu and Fe in solutions associated with sulfuric acid leached mine waste rock

 Solutions from oxidized waste rock originating from an acid-leached waste dump were studied. The dissolution data suggest that after the majority of the soluble solid phases are removed, remaining solid phases continued to buffer the solutions in the acidic pH range. Incorporating the solution data into MINTEQA2 identified controls on the solubility of Al, Cu and Fe at pH values from about 2.5 to slightly over 5. Sulfate appears to play a significant role in the formation of solubility controlling solid phases for Al and Cu. This is not the case for Fe, and is suggested that Fe and Cu solubility may be controlled by cupric ferrite at low pH values. Received: 5 April 1998 · Accepted: 27 July 1998     

Mineralogical and chemical characterization of wastes from the sulfuric acid industry in Falun, Sweden

 Wastes from the sulfuric acid industry are an environmental concern, because of the emission of acids, heavy metals, and sulfate to the environment. The wastes in Falun consist of 70–80% iron oxides, 10–20% silicates, less than 10% residual sulfides, and small amounts of secondary precipitates (iron hydroxides and Fe-, Zn- and Cu-sulfates). Due to the different behavior of sulfides during the roasting process, pyrrhotite and sphalerite are the major sulfide residues associated with lesser amounts of pyrite, chalcopyrite, and galena. The leachates are low-pH and enriched in Zn, Fe, and SO₄. The acid ferric Fe-rich solution promotes the dissolution of sphalerite and favors the formation of Pb-sulfate coatings on galena, providing an armoring effect which slows down the further oxidation of the galena. The residual sulfides are the potential source for acid generation and metal release. During the roasting process, iron oxides retain small amounts of sulfur and sphalerite forms alteration rims containing Zn-oxides. The iron oxides and Zn-oxides are important contributors to SO₄ and Zn in the leachates. The conditions in the waste deposit are favorable for the precipitation of Zn-, Cu-Fe-sulfates (e.g. gunningite, chalcanthite, Zn-copiapite). The highly soluble sulfates play important roles in controlling the concentrations of Cd, Cu, Fe, Zn, and SO₄ in the leachates. The mineralogical and geochemical data help to develop the reclamation strategies of this type of industrial wastes. Received: 26 April 1996 · Accepted: 27 July 1996     

硫酸和硝酸对桂林毛村碳酸盐岩溶蚀的室内模拟

硫酸和硝酸对碳酸盐岩的溶蚀会减少岩溶碳汇量,但其定量关系有待进一步研究。文章根据野外水体中SO42-、NO3-浓度,在室内封闭条件下分别设计了碳酸（0.033 mol?L-1）、硫酸和硝酸（0.1~1.7 mmol?L-1）（CSN酸）及硫酸、硝酸（0.1~1.7 mmol?L-1）（SN酸）对碳酸盐岩的溶蚀实验,实验历时144 h。结果表明:CSN酸中泥晶灰岩和白云岩的溶蚀速率均大于SN酸的。CSN酸中,泥晶灰岩溶蚀速率总体均高于白云岩,平均值分别为1.34 mg?（cm2?d）-1和1.21 mg?（cm2?d）-1。而在SN酸中,二者溶蚀速率差别不大,平均值分别为0.92 mg·（cm2?d）-1和0.93 mg·（cm2?d）-1;HCO3-浓度与溶蚀速率结果对应,泥晶灰岩和白云岩在CSN酸溶蚀液中HCO3-平均值分别为1.43 mmol?L-1和1.33 mmol?L-1,而在SN酸中泥晶灰岩的HCO3-低于白云岩,平均值分别为0.33 mmol?L-1和0.39 mmol?L-1。CSN酸中HCO3-浓度随酸浓度的增大而减小,而SN酸中其浓度随酸浓度的增大而增大。当SO42-、NO3-浓度为0.1~0.3 mmol?L-1时,碳酸对白云岩的溶蚀作用占75.89%~58.64%,对泥晶灰岩的溶蚀作用占80.21%~59.06%,当SO42-、NO3-浓度大于0.44 mmol?L-1时,其溶蚀作用小于50%。当SO42-、NO3-浓度为0.0~0.2 mmol?L-1时,野外实测数据与模拟数据基本吻合;当浓度>0.2 mmol?L-1时,野外实测碳酸对碳酸盐岩的溶蚀比例高于模拟实验。研究结果进一步说明了硝酸和硫酸对碳酸盐岩溶蚀作用的显著影响,可为其他酸对岩溶碳汇影响提供参考。      

Scandium,chromium, iron,cobalt and nickel in some basic and ultrabasic rocks from west Norway

Sixteen eclogites and ultrabasic rock samples from west Norway have been analyzed for Sc, Cr, Fe, Co and Ni by instrumental neutron-activation analysis.In gneiss-eclogites, Sc and Co give values from about 30 to 60 ppm and Cr and Ni from 180 to 700 ppm. An eclogite surrounded by a peridotite body shows nearly the same content of Sc and Co as do the gneiss-eclogites, but up to 20 times more Cr. Ni is only slightly more enriched in this particular eclogite than in the others.The ultrabasites have only a few ppm Sc, Co concentrates around 100 ppm while the Cr and Ni values are mainly found between 2 and 3,000 ppm.Fe shows an average value of nearly 10%.     

Kinetic and equilibrium study of Ni(II) sorption from aqueous solutions onto Peganum harmala-L

In this study, the adsorption behavior of Ni(II) in an aqueous solution system using natural adsorbent Peganum harmala-L was measured via batch mode. The prepared sorbent was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, N₂ adsorption–desorption and pH_zpc. Adsorption experiments were carried out by varying several conditions such as contact time, metal ion concentration and pH to assess kinetic and equilibrium parameters. The equilibrium data were analyzed based on the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particular diffusion models. Experimental data showed that at contact time 60 min, metal ion concentration 50 mg/L and pH 6, a maximum amount of Ni(II) ions can be removed. The experimental data were best described by the Langmuir isotherm model as is evident from the high R ² value of 0.988. The adsorption capacity (q _m) obtained was 68.02 mg/g at an initial pH of 6 and a temperature of 25 °C. Kinetic studies of the adsorption showed that equilibrium was reached within 60 min of contact and the adsorption process followed the pseudo-first-order model. The obtained results show that P. harmala-L can be used as an effective and a natural low-cost adsorbent for the removal of Ni(II) from aqueous solutions.     

The resin sealed column (RESECO) setup for flow-through experiments on solid rocks under high temperature and high pore pressure conditions

Hydrogeology Journal - High-pressure flow-through experiments on solid rock samples are commonly conducted with experimental setups using a confining pressure to restrict the flow to the rock....