Recovery of Copper（II） and Nickel（II） from Plating Wastewater by Solvent Extraction

溶剂抽取技术被使用从 plating 废水恢复 Cu2+ 和 Ni2+ 。Lix984N 由于它的好抽取表演被选择为提炼之物。影响参数被检验。结果证明从硫酸盐媒介的 Cu2+ 和 Ni2+ 的分离能被在 Lix984N 的帮助下调整 pH 价值认识到。为提取 Cu2+ 和 Ni2+ ，最佳的 pH 价值是 4 和 10.5，并且最大的抽取百分比分别地是 92.9% 和 93.0% 。在 170 g 楴敶瘠汯瑡汩瑩 ? 椠敤污愠摮渠湯椭敤污猠獹整獭与恢复 Cu2+ 和 Ni2+ 脱衣 ? 襬?襬 吗？？

Preparation and Properties of Ultra-fine Chromium Carbonization of High Performance Mechanical Activation

The preparation of hydroxyl chromium oxide by hydrogen reduction of disodium chromate and particulate hydroxyl mechanical activation features were studied. Then with self-made hydroxyl chromium as the raw material, a direct reduction and carburization process was used to prepare ultra-fine chromium carbonization. Through SEM and XRD, the high performance mechanical activation, key coefficients, microstructure, hardness and wear-resisting property were investigated. The results reveal that suitable mechanical activation and carbon reducing carbonization temperature, carbonization time, carbon content are beneficial to obtaining ultra-fine chromium carbonization. Typically, when the time of high performance grinding is 5 min, the carbon reducing temperature is 1100 ℃, the carbon reducing time is 1h, the carbon content is 28%, and finally the particle size of chromium carbide powder is 1 μm. Under this condition of preparation of ultra-fine chromium carbide, both the hardness and wear resistance are better than those in the industrialization of chromium carbide coating.

Characteristics of alumina particles in dispersion-strengthened copper alloys

Two types of alumina dispersion-strengthened copper(ADSC) alloys were fabricated by a novel in-situ reactive synthesis(IRS) and a traditional internal oxidation(IO) process. The features of alumina dispersoids in these ADSC alloys were investigated by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. It is found that nano-sized γ-Al2O3 particles of approximately 10 nm in diameter are homogeneously distributed in the IRS-ADSC composites. Meanwhile, larger-sized, mixed crystal structure alumina with rod-shaped morphology is embedded in the IO-ADSC alloy. The IRS-ADSC composites can obtain better mechanical and physical properties than the IO-ADSC composites; the tensile strength of the IRS-ADSC alloy can reach 570 MPa at room temperature, its electrical conductivity is 85% IACS, and the Rockwell hardness can reach 86 HRB.

Variation law of gas holdup in an autoclave during the pressure leaching process by using a mixed-flow agitator

The multiphase reaction process of pressure leaching is mainly carried out in the liquid phase. Therefore, gas holdup is essential for the gas–liquid–solid phase reaction and the extraction rate of valuable metals. In this paper, a transparent quartz autoclave, a six blades disc turbine-type agitator, and a high-speed camera were used to investigate the gas holdup of the pressure leaching process. Furthermore, experiments determining the effects of agitation rate, temperature, and oxygen partial pressure on gas holdup were carried out. The results showed that when the agitation rate increased from 350 to 600 r/min, the gas holdup increased from 0.10% to 0.64%. When the temperature increased from 363 to 423 K, the gas holdup increased from 0.14% to 0.20%. When the oxygen partial pressure increased from 0.1 to 0.8 MPa, the gas holdup increased from 0.13% to 0.19%. A similar criteria relationship was established by Homogeneous Principle and Buckingham's theorem. Comprehensively, empirical equation of gas holdup was deduced on the basis of experimental data and the similarity theory, where the criterion equation was determined as ε=4.54×10^(-11)n^(3.65)T^(2.08)P_g^(0.18). It can be seen from the formula that agitation rate made the most important impact on gas holdup in the pressure leaching process using the mixed-flow agitator.

白钨矿NaOH-SiO_(2)焙烧-水浸高效提取钨

针对NaOH-SiO_(2)焙烧-水浸法从白钨矿中高效提取钨进行了研究。首先,对NaOH-SiO_(2)焙烧分解白钨矿热力学进行了分析,结果表明在该焙烧条件下CaWO_(4)转化成Na_(2)WO_(4)和Na_(2)CaSiO_(4)从热力学角度是可行的;其次,研究了焙烧分解与水浸工艺参数对提取钨的影响,在Na_(2)O与WO_(3)摩尔比为2.2、SiO_(2):WO_(3)摩尔比为1、焙烧温度为700℃、焙烧时间2 h的条件下,通过控制液固比为3.2:1、水浸温度为80℃、浸出4 h后,钨的浸出率达到99.33%,浸出渣含钨为0.71%。进一步的物相分析表明,在NaOH-SiO_(2)焙烧过程中,白钨矿中的CaWO_(4)高效转化成Na_(2)CaSiO_(4)和Na_(2)WO_(4)。本研究结果为白钨矿采用火法高效提取钨提供了新路径。

Characterization and Thermodynamics of Al_2O_3-MnO-SiO_2(-MnS)Inclusion Formation in Carbon Steel Billet

A method to extract inclusion particles from solid steel by electrolysis with organic electrolyte solution was introduced;meanwhile,thermodynamics of inclusion formation was calculated using FactSage software.The results showed that there were two kinds of inclusions in the billet,i.e.Al2O3-MnO-SiO2-MnS(AMS-MnS)and Al2O3-MnO-SiO2(AMS).Most of AMS-MnS inclusion particles,with diameter of 10-30μm,showed three-layer structures:SiO2-rich core with a small quantity of Mn,intermediate AMS layer,and MnS outer layer containing small quantities of Al and O.Most AMS inclusion particles were 50-90μm and exhibited homogeneous composition.Thermodynamic results indicated that SiO2-rich core could form firstly by Si reacting with O in molten steel at temperatures above 1 923 Kduring Si-Fe alloy addition,and then,the SiO2-rich core could react with Mn and Al to form liquid AMS enveloping the SiO2-rich core at 1 823-1 873 K.MnS began to precipitate from AMS when temperature reached 1 728 K.Liquid AMS could form by coupled reaction among Si,Mn,Al and O in molten steel.

Fe^3+/Fe^2+自沉淀催化人工闪锌矿的氧压酸浸

本文研究了Fe^3+/Fe^2+自沉淀催化闪锌矿氧压酸浸的机理。利用ZnS和FeS烧结制备了具有不同铁含量的人造闪锌矿,并将其用于加压酸浸实验。利用自行设计的电位高压釜,研究了压力浸出系统的电势变化。结果表明,与不含铁闪锌矿相比,加压浸出过程中含25.70%铁的人造闪锌矿与溶解氧之间发生剧烈的氧化还原反应。催化机理归因于氧化还原对Fe^3+/Fe^2+,其中Fe3+氧化H2S气膜,还原的Fe2+随后被溶解氧氧化。此外,研究了温度、H2SO4浓度和氧分压对不同铁含量的人造闪锌矿的影响。与不含铁的样品相比,含铁的闪锌矿样品更容易溶于硫酸。铁含量为25.70%(22.26k J/mol)的人工闪锌矿的活化能比不含铁样品的活化能低(32.31k J/mol),并分别得到H2SO4浓度(1.10和1.36)和氧分压(1.29和1.41)的表观反应级数。根据实验数据和拟合的动力学图谱,建立了相关的动力学模型,并得到了Fe^3+/Fe^2+自沉淀催化闪锌矿浸出的动力学方程。

湿法酸浸锌渣硫酸熟化-富氧氯化浸出提取铅、银的实验研究

常规湿法炼锌过程中会产生大量的酸浸渣,该残渣含有大量各种有价值的金属。本研究的目的是评估使用硫酸熟化、水浸和氯化浸出(吹氧技术)回收铅和银的能力,接着通过冷却结晶并用铅片置换出银,实现酸浸锌渣中所有有价金属的全面回收,该工艺取得了良好的效果。条件实验研究得出最佳工艺条件如下:硫酸用量为原样质量的70%,焙烧温度300℃,焙烧时间2 h,焙烧渣按液固比5꞉1室温水浸1 h,此时锌、铁的浸出率最高(锌:98.69%,铁:92.36%)。氯化浸出系统主要参数如下:Cl−浓度300 g/L,Fe3+浓度25 g/L,酸浓度2 mol/L,液固比9 mL꞉1 g,温度90℃,浸出时间0.5 h,该条件下铅和银浸出率分别高达98.87%和96.74%;最后,对在富氧介质下使用Cl−浸出银进行动力学研究,发现浸出过程受内扩散控制,活化能为19.82 kJ/mol。

Palladium-catalyzed cyclization of 1-alkynyl-8-iodonaphthalene and double isocyanides for the synthesis of acenaphtho[1,2-b]pyrroles

A palladium-catalyzed formal[2+2+1]cyclization of 1-alkynyl-8-iodonaphthalene with double isocyanides is developed herein.The transformation worked well to produce a series of 7 H-acenaphtho[1,2-b]pyrrole with a broad reaction scope.Isocyanides play a dual role in the reaction.One is a C1 building block,and another is used as C1 N1 component.In the process,the[2+2+1]cyclization involves imidoylation,regioselective addition of imidoylpalladium species into alkyne,double imidoylation,and another addition of the resulting imidoylpalladium species into imine bonds.

4-叔丁基-2-(α-甲基苄基)苯酚萃取分离碱液中的钾和钠

本文研究了在碱性溶液中用取代酚类萃取剂分离钾和钠。4-叔丁基-2-(α-甲基苄基)苯酚(t-BAMBP)比4-仲丁基-2-(α-甲基苄基)苯酚(BAMBP)具有更好的提钾效果。最佳萃取条件为:1 mol/L t-BAMBP,相比(O/A)3:1,萃取级数两级。通过错流萃取,钾的萃取率达90.8%。用去离子水按4:1的相比进行4级洗涤,钠的洗涤率为88.2%。用1 mol/L H_(2)SO_(4)按3:1的相比反萃,钾的反萃率达94.2%。钾/钠(K/Na)浓度比从料液中的0.15增加到了反萃液中的2.3,增加了14.3倍。使用t-BAMBP进行溶剂萃取,可实现碱液中钾和钠的高效分离。

Non-ammonia enrichment of rare earth by magnesium oxide from rare earth leaching liquor in magnesium salt system

In order to solve the problem of ammonia-nitrogen pollution in the enrichment process of the ionadsorption type rare earth ore,the technology of non-ammonia precipitation with magnesium oxide precipitant was carried out.It is determined that the rare earth precipitation efficiency is 99.6%and the purity of rare earth concentrates is only 85.89 wt%under the optimum precipitation conditions.And the contents of MgO,SO3 and Al2O3 in the rare earth concentrates are 5.12 wt%,6.77 wt%and 1.78 wt%,respectively.Furthermore,the thermo-decomposition process of precipitates was investigated by TGDSC,XRD and FI-IR.The thermal decomposition process consists of two stages:the dehydration of rare earth hydroxide and alkaline rare earth sulfate within 900℃and the thermal decomposition of RE2O2SO4 at 900-1300℃.Therefore,a high-temperature calcinations method for removing SO3 from precipitates is proposed.When the precipitates are calcined at 1300℃for 2 h,the rare earth concentrates with a purity of 92.03 wt%can be acquired.Moreover,the content of SO3 in the concentrate is only 0.46 wt%.In the MgO precipitation and high-temperature calcinations process,the raw material cost is low and the quality of rare earth concentrates is acceptable.It could have great significance for nonammonia enrichment of rare earth from the rare earth leaching liquor,and finally solve the problem of ammonia nitrogen in the extraction process of the ion-adsorption type rare earth ore within magnesium salt system.

Recovery of rare earths from ion-absorbed rare earths ore with MgSO_4-ascorbic acid compound leaching agent

The magnesium sulfate leaching technology for the ion-absorbed rare earths ore can solve the ammonia pollution problem existing in ammonium sulfate leaching process. However, the leaching capacity of magnesium sulfate is slightly weaker than that of ammonium sulfate, resulting in a bigger consumption of magnesium sulfate. In this paper, the MgSO_4-ascorbic acid compound leaching agent had been demonstrated to deal with the ion-absorbed rare earths ore. The ascorbic acid could form a stable coordination with rare earth ions, so that it can strengthen the leaching of ion-exchangeable phase.Moreover, ascorbic acid has a strong reductive property, it can leach the colloidal sediment phase rare earth as well. The present study investigates the effect of the initial pH and the composition of leaching agent on the rare earth leaching. It is determined that the rare earth leaching efficiency is 107.5% under the condition of pH 2.00,0.15 mol/L magnesium sulfate and 1.0 g/L ascorbic acid in leaching agent. In this case, the content of the ion-exchangeable phase and colloidal sediment phase rare earth in the leaching residues are both only 0.02‰. The leaching efficiency of colloid sediment phase rare earth can be 85.7%,so that the Ce partition in the leaching liquor increases to be 5.77%. The magnesium-ascorbic acid compound leaching agent is proposed to be a promising choice to deal with the ion-absorbed rare earths ore, which can realize the efficient leaching, low consumption of MgSO_4 and environmentally friendly leaching.

Photoredox-Catalyzed Functionalization of Alkenes w ith Thiourea Dioxide:Construction of Alkyl Sulfones or Sulfonamides

Summary of main observation and conclusion Sulfonylation of alkenes through photoredox-catalyzed functionalization of alkenes with thiourea dioxide under visible-ight rradiation is achleved,The reaction of alkenes,thiourea dioxide and electropiles provides a green and fficient access to alkyl sul-fones and sulfonamides.A broad reaction scope is presented with good functional group compat bility and excellent regiaselectivity.A plausible mecha-nism involving a radical addition process with sulfur dioxide rpdical anion(SO2-)derived from the oxidation of sulfur dioxide anion(S02^-2) is proposed,which is supported by fluorescence quenching experiments.

High Strength Electrospun Single Copolyacrylonitrile(coPAN)Nanofibers with Improved Molecular Orientation by Drawing

High-performance carbon nanofibers are highly dependent on the performance of their precursors,especially polyacrylonitrile(PAN).In this work,the copolymer of PAN(coPAN)was synthesized for electrospinning.A self-assembling set-up was used for the stretching of single coPAN nanofibers.FTIR and Raman spectroscopies were used to characterize the chemical structure of coPAN nanofibers.Scanning electron microscopy(SEM)and atomic force microscopy(AFM)were used to monitor the morphology of single coPAN nanofibers under different drawing times.Micro-tensile test was used to determine the mechanical properties of single coPAN nanofibers.The results indicated that the drawing led to an increase in degree of molecular orientation along the fiber axis from 0.656 to 0.808,tensile strength from 304 MPa to 595 MPa,and modulus from 3.1 GPa to 12.4 GPa.This research would provide fundamental information of high-performance electrospun coPAN nanofibers and offer opportunities for the preparation of high-performance carbon nanofibers.

Strength Activity Index of Air Quenched Basic Oxygen Furnace Steel Slag

Air quenched basic oxygen furnace steel slag(BOF-SS)is processed at very high cooling rate,which is expected to have different cementitious properties from conventional slowly cooled BOF-SS.For this purpose,the strength activity indexes of air quenched and slowly cooled BOF-SS are investigated.The results reveal that,under the specific surface area(S) of 490m^2/kg,the compressive strength activity index reaches 1.24 after 28days with replacement of 15% air quenched BOF-SS and reaches 1.05 after 28days with replacement of 20% air quenched BOF-SS and 30% granulated blast furnace slag(GBFS).The cementitious activity of air quenched BOF-SS is obviously higher than that of slowly cooled BOF-SS,mainly because it contains more C_3S and glassy phases.