Thermodynamics of Cu(Ⅱ)-NH_3-NH_4Cl-H_2O system

1 INTRODUCTIONAmmonia metallurgy has the merits of a highleaching rate , good selectivity , easy purificationprocess ,so until nowit was still studiedin a greatarea[1 4]. We have previously studied on the ther-modynamics in the systems of Zn(Ⅱ)-NH3-(NH4)2SO4-H2O[5], Zn(Ⅱ)-NH3- ( NH4)2CO3-H2O[6]and Zn(Ⅱ)-NH3-NH4Cl-H2O[7]and dis-covered the rules of zinc solubility in these sys-tems .The former two systems were usedto supplethe theoretic basis for producing the high gradezinc o…     

聚醚添加剂对Zn(Ⅱ)-NH_3-NH_4Cl-H_2O体系电积锌的影响

针对现行氨法电锌存在的阴极锌板表面不平整、疏松多孔、边缘毛刺突出等一系列问题,研究聚醚添加剂对Zn(Ⅱ)-NH_4Cl-NH_3-H_2O体系电积锌的影响,并考察添加剂浓度对沉积锌表面形貌、沉积锌晶体结构、电流效率、平均槽电压和能耗等各项工艺参数的影响。结果表明:添加剂的使用可以使电积得到的阴极锌表面光滑平整,致密与无毛刺,锌晶面表现出高择优取向,生长择优方向为(110)晶面,晶体为六方密堆结构,晶粒细小;在最佳浓度为1.0 g/L时,平均槽电压为2.76 V,电流效率可高达92.88%,单位能耗为2435.72 k W·h/t。     

Thermodynamics of Cu（ Ⅱ ）-NH3-NH4Cl-H20 system

The thermodynamics of a complex solution system, Cu（ Ⅱ ）-NHa-NH4Cl-H2O, was presented both theoretically and experimentally. Firstly, according to the principles of simultaneous equilibrium and aqueous electronic charge neutrality of the system, a nonlinear mathematical thermodynamic model with multi-members was set up. In this model, there were six unknowns： pH value, concentration values of free Cl^- , free NH3 , total concentration values of Cu^2＋ , Cl^- and NHa, four equilibrium equations and three equilibrium equations of total quantum of Cu^2＋ , Cl^- and NH3 , as well as an equilibrium equation of electric charge, were involved in the model. Then after specifying the values of total concentrate of NH3 and Cl^- , the model was solved precisely using MATLAB language, and the other four unknowns were obtained. According to the values obtained above, various valuable figures regarding thermodynamic relation of the system were protracted also with MATLAB, including two and three dimensions figures. These figures and data can supply the theoretic conference for optimizing the ratio of leaching reagents in copper extraction through ammonia hydrometallurgy. Finally, the solubility of CuO were measured in the system of NHa-NH4Cl-H2O. The results show that the model and the thermodynamic data obtained are reliable.     

Zn(Ⅱ)-NH3-Cl--CO32--H2O体系中Zn(Ⅱ)配合平衡

用双平衡法研究Zn(Ⅱ)-NH3-Cl--CO32--H2O体系中Zn(Ⅱ)配合平衡热力学,求出氨水浓度和氯离子浓度在0～10 mol/L范围内变化时,体系中各物种的平衡浓度,绘制热力学平衡图,并对热力学计算结果进行实验验证和差异分析.结果表明:锌离子浓度理论计算值与实验值之间的平均相对误差为7.47%,这说明该热力学模型是正确的,所选数据的准确性较好.     

Anodic reaction kinetics of electrowinning zinc in system of Zn （Ⅱ）-NH3-NH4Cl-H2O

The anodic reaction kinetics of zinc electrowinning was investigated on the titanium base RuO2 anode in the system of Zn(Ⅱ)-NH3-NH4Cl-H2O. The effects of stirring speed, ammonium chloride concentration and tem-perature on anodic reaction rate were studied through the curve measurement of potentiostatic polarization. The re-sults reveal that the electrochemically controlled anodic reaction obeys Tafel equation and the anodic reaction order for ammonium chloride is 1. 056, with the apparent activation energy of 40. 17 kJ/mol. The general equation of a-nodic reaction kinetics was obtained.     

NH_3-NH_4Cl-H_2O体系低品位硫化铜矿氧化浸出-脉冲电积工艺

采用单因素试验法,研究某低品位硫化铜精矿(Cu 7.42%(质量分数))在NH_3-NH_4Cl-H_2O体系中的氧化浸出行为。结果表明:在液固比4:1、[NH_3·H_2O]=1 mol/L、[NH4Cl]=3 mol/L、氧化剂过量系数1.4、原料粒度94～124μm、浸出时间2h、温度30℃的条件下,该低品位硫化铜矿浸出率98.89%;并在此基础上开展了从该低品位硫化铜精矿铜氨浸出液中直接脉冲电积铜的工艺优化试验。结果表明:在[NH_4Cl]=3 mol/L、[NH_3·H_2O]=1.5 mol/L、[Cu~(2+)]=20 g/L、明胶0.06 g/L、硫脲0.05 g/L、脉冲电流密度600 A/m2、占空比90%的条件下,可以获得平整光滑且有金属光泽的阴极铜,阴极电流效率87.97%。阴极铜XRD分析结果表明:氨-氯化铵体系中脉冲电积铜晶体主要沿(220)晶面生长,其余晶面未见明显反射峰,表现出类单晶结构。SEM分析显示:该阴极铜表面光滑致密且无瘤状物产生,铜在阴极表面的生长方式呈与阴极面垂直的一维方向生长。     

Thermodynamics and technology of extracting gold from low-grade gold ore in system of NH4Cl-NH3-H2O

1 Introduction Hydrometallurgy with ammoniacal ammonium chloride as extracting system is a new developing field with many merits. Above all, NH3 and Cl- ions existing in the system have relatively high complex ability with some heavy or noble metal ions. …     

Thermodynamic calculation of Sn(IV)-NH~(4 )-Cl~--H_2O system

1　INTRODUCTIONAntimonydopedtinoxide ,forshortATO ,withexcellentconductivityperformance ,isakindofmetaloxide powders .Duetoitswideapplication ,thepreparationandapplicationareabroadintheworld .Atpresent ,tincompoundssuchasSnCl4 ·5H2 O ,SnO2 andSn(OH) 4areusuallyusedtoprepareATOpowders[18] .Allthesestanniccompoundsarepre paredbypure ,expensivetin ;furthermore ,SnCl4 isveryeasytovolatilize ,whichcauseshardmeasure ment ;inaddition ,usingSnO2 orSnO2 ·2H2 Otopre pareATOdemandforrigo…     

硅锌矿在(NH_4)_2SO_4-NH_3-H_2O体系中的浸出机理

对硅锌矿在(NH4)2SO4-NH3-H2O体系中的浸出行为进行了系统研究,揭示浸出反应机理,阐明其难以浸出的内在原因。结果表明:硅锌矿浸出反应方程为Zn2SiO4(s)+(2i-4)NH3(aq)+4NH4+=2[Zn(NH3)i]2++SiO2(s)+2H2O(l),i=1～4。浸出中,硅锌矿中的硅溶解进入溶液,再以无定形SiO2形态从溶液中析出。SiO2在(NH4)2SO4-NH3-H2O体系中的溶解度很低,仅略高于0.3 g/L,而其从溶液中的析出速度非常缓慢,是硅锌矿在该体系中难以浸出的主要原因。当液固质量比从5提高至500时,锌浸出率将从2.72%提高至84.15%。     

新型萃取剂YORS萃取Zn(Ⅱ)-NH_3配合物体系中的锌

为有效地富集低品位氧化锌矿氨浸液中的锌离子,使用新型萃取剂2-乙酰基-3-氧代-二硫代丁酸-十四烷基酯(YORS)从Zn(Ⅱ)-NH3配合物体系中萃取锌。研究结果表明:在有机相组成50%YORS+45%H(稀释剂)+5%P(添加剂)、相比V(A)/V(O)=2-1、温度298.15 K、振荡时间5 min、总氨浓度2 mol/L、水相初始pH 9~11的最优条件下,锌的平均萃取率达97%以上,分配比Dex=41.74。对萃取剂和负载有机相进行红外光谱和紫外光谱分析,得到萃取剂和萃合物的分子结构,并证实在锌的萃取过程中萃取剂中的β-二酮与游离态Zn2+作用生成配合物,NH3未被萃取。     

Synthesis and Structure of Tetrapyridine Diperrhenate Zinc(Ⅱ) Complex py_4Zn(OReO_3)_2

Although a considerable nUmber of perrhenates of alkaline, alkaline-earth and transitionmetals have been Prepared and some of theirstrUctlires were determined [1,2], only a few ofthe complexes in which ReO. acts as the anionor ligand were synthesized and the crystal smicfores were described. For example, the comPlexes L.Cu(ReO.), (L=NH,, py) prepared by reaction of Cu(ReO.), with ammonia or pyridinewere reported [3], but no crystal struCtUre wasdetermined. The s~e of Ni(tmp),' ReO. was…     

采用Mextral54-100从Zn(Ⅱ)-NH_4Cl-NH_3配合物溶液中萃取锌

研究了采用β-二酮类萃取剂Mextral54-100(HA)从Zn(Ⅱ)-NH4Cl-NH3配合物溶液中萃取锌的行为,考察了溶液初始p H、温度、萃取剂浓度、氯离子浓度和总氨浓度对锌萃取的影响,结果表明:溶液p H、总氨浓度对锌萃取率的影响较显著。总氨浓度的增加降低了锌的分配比。当水相初始p H6.81时,分配比随着p H的增加而下降。萃取过程由于受锌氯配位影响,分配比随氯离子浓度升高呈下降趋势。萃取过程是一个放热的反应,298 K下,反应焓变为-4.720 k J/mol,温度升高不利于锌的萃取;锌以自由锌离子被萃取,萃合物的组成为Zn A2。萃合物的红外光谱表明:萃取剂分子中的β-二酮互变为烯醇式参与配位键的形成,锌氨络合物不被萃取。     

Synthesis of GdF3 from the Gd2O3-NH4HF2 system

GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.     

制取活性锌粉的Zn(Ⅱ)-NH3*H2O-(NH4)2SO4体系电解法

研究了在Zn(Ⅱ ) NH3 ·H2 O (NH4 ) 2 SO4 体系中电解制取活性锌粉新工艺。结果表明 :在常温下 ,电流效率高达 88.19%,每吨产品能耗为 32 5 4.37kW·h ,其产品质量符合GB6 890 86标准 ;活性锌粉杂质含量低 ,锌含量≥ 98.78%,有效锌含量≥ 96 %,锌的总回收率为 97.97%。该法与以金属锌为原料的蒸馏法、雾化法相比较 ,成本大幅度降低。     

硅酸盐在(NH_4)_2WO_4-(NH_4)_2CO_3-NH_3-H_2O体系中反应行为的热力学分析（英文）

含硅组分在(NH4)2WO4-(NH4)2CO3-NH3-H2O体系中的反应行为对仲钨酸铵清洁生产新技术的研发具有重要意义。为了探索此体系中硅的脱除方法,对含硅组分的反应行为进行系统的热力学分析。热力学计算结果表明,钨矿物焙烧熟料中的硅酸盐在浸出过程中会发生部分分解,25°C条件下溶出体系中硅浓度在热力学上可达到150～160 mg/L。溶液中溶解的硅可采用镁盐沉淀法除去,体系中低碳酸根浓度和高铵浓度有利于硅的脱除,当体系中总碳酸根浓度高于1.5mol/L时,硅酸镁沉淀难以形成。在合适的除硅条件下,在溶液中添加镁盐,硅浓度可降至8～10 mg/L。此外,研究体系中的钙和镁的反应行为,发现实验结果与理论计算结果一致。     

仲钨酸铵在(NH_4)_2CO_3-NH_3?H_2O-H_2O体系中的溶解行为（英文）

研究(NH_4)_2CO_3-NH_3?H_2O-H_2O体系中温度、氨水浓度和碳酸铵浓度对仲钨酸铵(APT·4H_2O)溶解行为的影响。结果表明:当温度低于90℃时,随着温度的升高、时间的延长、氨水浓度的增加和碳酸铵浓度的降低,APT·4H_2O溶解量增大;而当温度高于100℃时,溶解过程中APT·4H_2O溶解量先升高再下降;当温度低于90℃时,未溶解物仍以APT·4H_2O形态存在;当温度高于100℃时,未溶解物则主要以焦绿石型三氧化钨(WO_3·5H_2O)形态存在;溶解过程中,APT·4H_2O先溶解为仲钨酸根离子继而部分转变为正钨酸根离子,最终溶液中正钨酸根离子和仲钨酸根离子共存。该研究可为APT·4H_2O生产新工艺的开发和WO_3·5H_2O的制备提供新思路。     

Zn(Ⅱ)-Glu2--CO32--H2O体系热力学平衡分析

针对碱式碳酸锌(2ZnCO3·3Zn(OH)2)在L-谷氨酸一钠溶液中的热力学行为,根据配位化学理论绘制谷氨酸根(Glu2-)和碳酸根(CO32-)在溶液中的形态分布图;根据双平衡法理论研究Zn(Ⅱ)-Glu2--CO32--H2O体系中Zn(Ⅱ)的配合平衡热力学,并绘制L-谷氨酸一钠浓度在0～5 mol/L范围和pH在7～14范围内变化时的热力学平衡图,研究L-谷氨酸一钠浓度、pH值和游离碳酸根离子浓度对L-谷氨酸一钠浸出碱式碳酸锌的影响.同时对热力学计算结果进行实验验证.结果表明:在一定的L-谷氨酸一钠浓度下,当pH=10时,溶液中总锌浓度达到最大值;锌离子浓度理论计算值与实验值之间相对误差的绝对平均值为11.39%.     

制取活性锌粉的Zn(Ⅱ)-NH3·H2O-(NH4)2SO4体系电解法

研究了在Zn(Ⅱ)-NH3*H2O-(NH4)2SO4体系中电解制取活性锌粉新工艺.结果表明在常温下, 电流效率高达88.19%, 每吨产品能耗为3254.37kW*h, 其产品质量符合GB6890-86标准; 活性锌粉杂质含量低, 锌含量≥98.78%, 有效锌含量≥96%, 锌的总回收率为97.97% .该法与以金属锌为原料的蒸馏法、雾化法相比较, 成本大幅度降低.     

Kinetics of Thermal Decomposition for Complex [Zn(C_(16)H_(18)FN_3O_3)_2(NO_3)_2]·2H_2O

1 ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓ ,ｔｈｅｉｎｔｅｒａｃｔｉｏｎｂｅｔｗｅｅｎｎｏｒｆｌｏｘａｃｉｎａｎｄｃｅｒｔａｉｎｍｅｔａｌｌｉｃｉｏｎｓｈａｓｂｅｅｎｖａｌｕｅｄｗｉｄｅｌｙ[1～ 4].Ｂｕｔｔｈｅｎｏｎ ｉｓｏｔｈｅｒｍａｌｋｉｎｅｔｉｃｓｏｆ[Ｚｎ(ＮＦＡ) 2 (ＮＯ3) 2 ]·2Ｈ2 Ｏｔｈｅｒｍａｌｄｅｃｏｍ ｐｏｓｉｔｉｏｎｈａｓｒａｒｅｌｙｂｅｅｎｓｔｕｄｉｅｄ .Ｉｎｔｈｉｓｐａｐｅｒ ,ｗｅｄｉｓｃｕｓｓｅｄｉｔｓｔｈｅｒｍａｌｄｅｃｏｍｐｏｓｉ ｔｉｏｎｂｅｈａｖｉｏｒｂｙ…