Selective Separation of Metals from Deep-Sea Ferromanganese Nodules by Sulfur Dioxide Reduction

Abstract

An investigation of the reaction of deep-sea ferromanganese nodules with SO₂ has been carried out in the temperature range 300 and 600 [ddot]C. Maximum sulfation occurs with dehydrated nodules after treatment with a SO₂-O₂ gas mixture at 400 [ddot]C. X-ray photoelectron spectroscopy and x-ray diffraction techniques indicate that the oxides of manganese, which are major components in the nodules, are sulfated. The oxides of Cu, Ni, and Co are also converted into their sulfates when reacted with SO₂ and O₂, and Mn, Cu, Ni, and Co can be nearly quantitatively extracted by leaching the sulfated nodules. Iron, which is also a major component and present as goethite, a-FeO(OH), is not sulfated but transformed into hematite, α-Fe₂O₃. Thus it can be separated from other metals which form water-soluble sulfates during the high-temperature sulfation process.     

Separation of Metals from Sulfated Deep-Sea Ferromanganese Nodules by Adsorbing Colloid Flotation

Abstract

Adsorbing colloid flotation (ACF) is applied to aqueous leach solutions of sulfated deep-sea ferromanganese nodules and their process tailings. Metal cations of Cu, Co, Ni, Mn, Al, and Zn are separated simultaneously by flotation with hydroxide collectors and cationic surfactants from the leach liquors of sulfated ferromanganese nodules. Applications of ACF to the nodule tailings also makes possible the recovery of residual Cu, Co, Ni, Ti, Zn, Al, Fe, Mn, and the separation of Pb and V, the most abundant toxic species in the nodules and tailings.     

Separation of Metals from Sulfated Deep-Sea Ferromanganese Nodules with Organic Precipitating Reagents and Adsorptive Bubble Techniques

Abstract

Organic precipitating reagents and adsorptive bubble techniques were used to separate copper, cobalt, nickel, and manganese from the leach liquors of sulfated deep-sea ferromanganese nodules. Recoveries of the four elements were examined as a function of pH and the quantity of the organic precipitating reagent added. Three reagents were studied: 8-hydroxyquinoline, ammonium 1-pyrrolidine-dithio-carbamate, and dithizone.     

The Separation of Metals from Treated Deep-Sea Ferromanganese Nodules by Adsorptive Bubble Techniques Using Salicylaldoxime and Sodium Diethyldithiocarbamate as Organic Precipitating Reagents

Abstract

An adsorptive bubble technique, using two organic precipitating reagents, is applied to separate cobalt, copper, nickel, and manganese from the leach liquors of sulfated deep-sea ferromanganese nodules. Recoveries of the four metal values are studied as a function of pH for each system. The organic precipitating reagents studied are salicylaldoxime and sodium diethyldithiocarbamate.     

Recovery of Metals from Process Streams of Deep-Sea Ferromanganese Nodules by Adsorptive Bubble Techniques

Abstract

A method for the separation of Cu, Co, Ni, and Zn with varying degrees of selectivity from chemically treated deep-sea ferromanganese nodules is described. Quantitative removal of these species is achieved primarily by precipitate flotation of insoluble sulfides. Recovery of residual metal values of Cu, Co, Ni, and Zn in process rejects of the nodules is also possible. The quantitative removal of Pb and V, which are the most abundant toxic elements in nodules and tailings, is achieved simultaneously. Cationic and anionic surfactants are employed for collection depending on zeta potentials of the flocs generated upon addition of Na₂S to sample solutions. Separations are more selective and efficient at lower pH than previously reported for flotation of metals from nodules as insoluble hydroxides. Modifications resulting in slight improvements over previously employed high temperature sulfation processes are also described.     

高铁锰矿熔融还原锰铁分离技术探讨

高铁锰矿往往由于锰、铁矿物之间的密切共生关系、分布力度细,锰铁分类质同向形态的存在,使得传统机械方法难以分离锰铁。铁和猛的氧化物在高温固态分离过程中存在一定相互影响因素,并且随着还原条件的变化,相互迁移渗透力逐渐增强,还原出来的铁猛不利于氧化物的分离。因此,主要以熔融还原铁猛分离技术为对象研究锰铁,从还原工艺流程中展开试验探究,从高铁锰矿熔融还原锰铁分离技术特点展开研究。     

钼尾矿中方解石、白云石分选试验研究

为了分离出钼尾矿基陶瓷掺料中的方解石、白云石矿物,以水玻璃为抑制剂、油酸钠为调整剂、十二烷基胺为起泡剂,采用浮选方法对辽宁某钼尾矿进行了试验研究,并采用热力学计算对油酸钠捕收方解石、白云石的机理进行分析.结果表明,油酸根以化学吸附形式与矿物表面Al3+、Ca2+、Mg2+形成难溶油酸盐,附着于目的矿物表面,调整油酸钠的添加量,可实现金云母、方解石和白云石的分选富集;pH＜ 8.87时,油酸根优先捕收金云母;pH ＞9.3时,油酸根优先捕收方解石和白云石.     

Surface Selective Approach to Separation of Propylene from Propane

Abstract

Membranes with high separation factors and permeation values are important for the success of high temperature membrane reactors. Microporous membranes with molecular sieving ability are potential candidates. In situations were the molecular size of the gases to be separated are very near, however, such size exclusion is not possible. The present paper describes a new technique to modify such microporous membranes by making use of special materials with adsorption selectivity to the gases in question. More importantly, the paper points out that the same adsorption selectivity does not always guarantee gas separation. The total adsorbed volume and the number of available sites are also influential in determining the real separation factors. By using the said technique, a membrane system is developed and tested for use in separating propylene from propane with commendable separation and permeation values.     

Selective Separation of Palladium from Organic Solutions Containing Nickel or Platinum using Polythioamide as a Sorbent

The feasibility of the selective recovery of Pd from organic liquid waste using polythioamide (PTA) as a sorbent has been investigated. PTA effectively sorbed Pd(II) in some organic solutions under not only acidic conditions but also basic conditions. PTA was also able to sorb Pd from organic solutions containing PdCl₂(PhCN)₂ and Pd₂(dba)₃. The results for the molecular structure of a model compound ([Pd(C₁₁H₁₅NS)₄]Cl₂) suggest that the presence of a S donor plays an important role in the sorption of Pd(II) by PTA. The sorbed Pd was quantitatively eluted using 1,3-bis(diphenylphosphino)propane in MeOH, and the recovered PTA can be reused at least five times. The selective separation of Pd(II) was achieved even from organic solutions containing a 100 times larger amount of Ni(II) or Pt(IV) under acidic conditions or basic conditions, respectively.     

Selective Separation of Toluene from n‐Heptane via Emulsion Liquid Membranes Containing Substituted Cyclodextrins as Carrier

Abstract

The selective separation of toluene from n‐heptane is investigated using unsubstituted α‐cyclodextrin (αCD), β‐cyclodextrin (βCD) and also with two substituted CDs as a carrier in oil/water/oil‐type emulsion liquid membranes. The separation factor for toluene to n‐heptane is evaluated from the extraction of an equimolar mixture of toluene and n‐heptane. βCD shows the highest selectivity followed by αCD, hydroxypropyl‐αCD and hydroxypropyl‐βCD. The separation performances, represented by the permeation rate and separation factor, are analyzed systematically by varying the operating parameters: contact time, concentration of carriers, volume fraction of the membrane phase, and the relative amount of solvent. In this paper the effects of carriers and interfacial tension on dispersed phase drop size, internal droplets size, and size distribution are also systematically investigated.     

Selective Separation and Preconcentration of Total Tin Using Quercetin as Chelating Agent

Abstract

Three methods were developed for rapid and selective extraction of total tin as Sn(IV) using quercetin (H5Q) as chelating agent, prior to its determination by hydride generation atomic absorption spectrometry (HGAAS). H5Q was chemically or physically immobilized onto silica gel or polyurethane foam, respectively, and used for the separation of Sn(IV) by the solid phase extraction (SPE) technique. The SPE methods were compared with flotation technique using the oleic acid as surfactant from H5Q solution in amyl alcohol/kerosene solvent. Elemental analysis, thermogravimetry, spectroscopic measurements (IR, UV/vis and magic angle solid state C¹³‐NMR) were used to characterize the resulting modified extractors. The experimental conditions for efficient extraction of Sn(IV) such as: pH, time of stirring, interfering ions and eluent concentration, were optimized for the batchwise separation process. The tolerance limits of heavy metal ions in the sorption of Sn(IV) were reported. The methods were applied for the determination of total tin in water samples, zinc shots and canned beans after digestive oxidation. The suggested SPE and flotation techniques were found to be accurate and not subject to random error with especial preference to the SPE technique as it is cheaper and simpler.     

A Rapid Adsorbing Colloid Flotation Method for the Separation of Molybdenum from Sea water

Abstract

A procedure is described whereby the molybdenum in a 500-ml seawater sample is brought to the surface in 5 min by an adsorbing colloid flotation process which utilizes iron(III) hydroxide, sodium dodecyl sulfate, and air. Statistical studies on a test series for recovery of molybdenum by means of spectrophotometric analysis show a mean recovery of 95.3% and a relative standard deviation of 2.6%.     

Comparative Study of Selective Separation of Magnesium from Brine and Seawater

Abstract

A highly selective, sensitive, and inexpensive procedure for the separation of magnesium from brine and seawaters is proposed. The method is based on the separation of the harmful major constituent (calcium) of saline water. This is achieved by floating both calcium and magnesium as their oleates at the pH of saline water (7.5–8.5) to avoid the effect of NaCl on the precipitation of Ca as CaSO₄. The float is dissolved in HNO₃/methanol, precipitated as CaSO₄, and the mother liquor is refloated as pure magnesium oleate. This purity is confirmed by infrared measurements.     

Selective Hydrogenation of Amides using Ruthenium/ Molybdenum Catalysts

Recyclable, heterogeneous bimetallic ruthenium/molybdenum catalysts, formed in situ from triruthenium dodecacarbonyl [Ru₃(CO)₁₂] and molybdenum hexacarbonyl [Mo(CO)₆], are effective for the selective liquid phase hydrogenation of cyclohexylcarboxamide (CyCONH₂) to cyclohexanemethylamine (CyCH₂NH₂), with no secondary or tertiary amine by‐product formation. Variation of Mo:Ru composition reveals both synergistic and poisoning effects, with the optimum combination of conversion and selectivity at ca. 0.5, and total inhibition of catalysis evident at ≥1. Good amide conversions are noted within the reaction condition regimes 20–100 bar hydrogen and 145–160 °C. The order of reactivity of these catalysts towards reduction of different amide functional groups is primary>tertiary≫secondary. In situ HP‐FT‐IR spectroscopy confirms that catalyst genesis occurs during an induction period associated with decomposition of the organometallic precursors. Ex situ characterisation, using XRD, XPS and EDX‐STEM, for active Mo:Ru compositions, has provided evidence for intimately mixed ca. 2.5–4 nm particles that contain metallic ruthenium, and molybdenum (in several oxidation states, including zero).     

Selective Separation of Gallium from Acidic Leach Solutions by Emulsion Liquid Membranes

Abstract

The separation and concentration of gallium from acidic leach solutions, containing various other ions such as iron, cobalt, nickel, zinc, cadmium, lead, copper, and aluminium, by an emulsion liquid membrane (ELM) technique using tributyl phosphate (TBP) as carrier has been presented. Liquid membrane consists of a diluent, a surfactant (ECA 4360J), and an extractant (TBP), and 0.1 M HCl or 0.1 M H₂SO₄ were used as the stripping solution. The important variables governing the permeation of gallium and their effect on the separation process have been studied. These variables were membrane type and composition, mixing speed, diluent type, surfactant concentration, extractant concentration, HCl concentration in the feed, acid type of stripping phase, feed concentration, and treatment ratio. The optimum conditions were determined. It was possible to selectively extract 96.0% of gallium from the acidic leach solutions, containing Fe, Co, Ni, Zn, Cd, Pb, Cu, and Al, at the optimum conditions.     

铜钼矿石的浮选及铜钼分离工艺

详细阐述了铜钼矿石的分离工艺和进展,包括混合浮选和抑铜浮钼流程;考察了铜抑制剂硫化钠,巯基乙酸及新型铜抑制剂的研究进展。针对铜钼分离中出现的主要问题,详细探讨了电位调节、热处理、充氮浮选、浮选柱及脉动高梯度磁选在铜钼分离中的应用,提出了铜钼分离研究的方向。     

从废旧高温合金的硫酸浸出渣中浸出分离钨钼铼

对废旧高温合金硫酸浸出残渣选择HCl-FeCl3-H2O2体系氧化浸出、浸出后加入NaOH调节溶液pH值,使钨、钼、铼与铌、钽等分离,研究了反应时间、反应温度、HCl用量、FeCl3用量、H2O2用量对钨、钼、铼浸出率的影响. 结果表明,该体系能充分浸出渣中钨、钼、铼3种金属,添加FeCl3可提高钼在盐酸溶液中的浸出率. 在浸出温度70℃、浸出时间5 h、FeCl3用量100 g/L、H2O2用量10 mL/g及HCl初始用量10 mL/g的条件下,钨、钼、铼浸出率分别大于97%, 86%, 91%.     

Separation of Phobane Isomers by Selective Protonation

The industrially important mixture of sym‐ and asym‐phobanes are separated efficiently by selective protonation of the sym isomer with hydrochloric acid; carbonylation catalysts generated from diphosphanes derived from the separated isomers have quite different activities and product selectivities.     

萃取法回收二硫化钼废水中的钼

采用萃取法对二硫化钼废水中钼的回收进行试验研究,得出了较佳工艺参数。研究结果表明:通过萃取使废水中钼含量降到1g/L以下,萃取后废水杂质含量和含油量均达到了排放标准。