复杂钴白合金硫化焙烧酸浸过程中钴的提取行为

本文针对钴白合金中钴难以实现高效节能回收的研究现状,以复杂钴白合金为研究对象、辉钼矿为焙烧硫化剂,通过钴白合金硫化焙烧-常压硫酸浸出工艺实现了钴的高效选择性提取。考察了焙烧温度、辉钼矿添加量和焙烧时间等对钴浸出的影响,并且通过XRD分析了焙烧及酸浸过程中的物相转变。结果表明：在焙烧温度1050℃、辉钼矿和钴白合金的质量比2∶1、焙烧时间90 min的条件下,钴白合金与辉钼矿反应转化为高浸出性能的三元硫化物(M_xMo₆S₈,M=Co, Fe, Cu;x=0～2),随后在常压硫酸浸出过程中,钴和铁被选择性浸出,浸出率均大于99%;而钼和铜不被浸出,以Cu_0.5Mo₃S₄和Mo₃S₄的形式富集于浸出渣中。此外,辉钼矿中的钼被转化为三元硫化物(MxMo6S8),钼的浸出性能也大大提高。     

氧化焙烧从废弃锰矿中回收钴的研究

采用氧化焙烧的方式对废弃的菱锰矿中微量钴进行了提取工艺条件的研究,实验考查了焙烧温度,焙烧时间,浸取温度和浸取剂的浓度等对钴浸出率的影响,结果表明：焙烧温度为９００℃时,焙烧停留时间为１ｈ,硫酸浸取剂为３００￣４００ｇ／ｌ,浸取温度为９０℃,浸取时间为１ｈ,固液比为１：５,钴的浸出率达到８５％以上,铁的浸出率为４０％以上,锰的浸出率为３０％,达到了初步分离富集的目的。实验结果表明当焙烧温度在７００     

从钼钴废催化剂中回收钼

采用加压浸出从钼钴废催化剂中分离钼,在原料摩尔比Na_2CO_3/Mo=1.3,浸出温度150℃的条件下,钼的浸出率达90%。浸出液经酸化处理后采用N235萃取回收,在有机相为20%N_(235)-10%异辛醇-煤油的条件下,经4级萃取钼的萃取率可达到99.6%。反萃液经酸沉回收钼,产品钼酸铵质量较好。本工艺流程简单、有价金属回收率高、对环境友好。     

从钼钴废催化剂中回收钼

采用加压浸出从钼钴废催化剂中分离钼,在原料摩尔比Na2CO3/Mo=1.3,浸出温度150℃的条件下,钼的浸出率达90%.浸出液经酸化处理后采用N235萃取回收,在有机相为20%N235-10%异辛醇-煤油的条件下,经4级萃取钼的萃取率可达到99.6%.反萃液经酸沉回收钼,产品钼酸铵质量较好.本工艺流程简单、有价金属回收率高、对环境友好.     

湿法炼锌净化渣酸浸的动力学

对湿法炼锌净化渣的浸出动力学进行了研究,并探讨了硫酸浓度、反应温度、粒度等对钴、锌浸出率的影响规律。从动力学的角度分析了整个浸出过程,得到优化条件：液固比50：1(mL/g),硫酸浓度100 g/L,反应温度70°C,粒度75~80μm,反应时间20 min。在此优化条件下钴的浸出率为99.8%,锌的浸出率为91.97%。结果表明：在硫酸体系中钴的浸出符合不生成固体产物层的“未反应收缩核”模型。通过 Arrhenius 经验公式求得钴和锌表观反应活化能分别为11.693 kJ/mol和6.6894 kJ/mol,这表明浸出过程受边界层扩散控制。     

复杂高硅钴白合金碱焙烧脱硅预处理

针对高硅钴白合金结构复杂、难以直接硫酸浸出问题,开展碱焙烧脱硅预处理研究以破坏稳定致密的硅铁合金结构。结果表明:经碱焙烧预处理后,钴白合金形貌发生明显改变。碱焙烧条件如下:温度600℃,NaOH用量为硅、铁反应所需理论量0.64倍。在上述条件下焙烧2 h后,所得渣经水洗,硅的脱除率达到66.57%;再经常压硫酸浸出,钴、铁浸出率均高达99%以上,而铜则完全保留在浸出渣中,实现了钴和铜分离,渣中的铜经第二段氧化浸出得以回收。进一步基于工艺矿物学分析,对碱焙烧脱硅预处理后钴白合金的常压浸出行为进行解析。     

还原酸浸法从低品位水钴矿中提取铜和钴

以Na2SO3为还原剂从水钴矿还原酸浸液中提取铜和钴,研究了还原剂种类及用量、浸出温度、硫酸浓度等因素对水钴矿还原酸浸过程中有价金属铜和钴浸出率的影响。结果表明,Na2SO3是较适宜的还原剂;在还原剂用量为水钴矿原矿质量的10%、硫酸浓度为3 mol/L、浸出温度为60℃、液固比为2-1、浸出时间为60 min的条件下,铜和钴的浸出率分别达99.06%和98.87%。并提出了"M5640萃铜→黄钠铁矾法除铁→碳酸钠除铝→氟化钠除钙、镁→蒸发结晶得钴产品"的后续分离净化流程,能有望应用于水钴矿及类似物料中有价金属的提取与分离的工业生产。     

硝酸氧化浸出难冶炼高砷钴矿

在100g钴矿加入39mL浓硫酸、浸出温度80℃、浸出时间2h、液固比2:1时,采用常规的硫酸浸出,钴浸出率仅为16.86%;当100g钴矿中加入42.5mL浓硫酸、在焙烧温度630℃、焙烧时间1.5h的焙烧条件下,采用硫酸化焙烧后硫酸浸出,钴浸出率达到67.48%;在100g钴矿中加入39mL浓硫酸和56mL浓硝酸、浸出温度60℃、浸出时间4h、液固比为3:1时,采用硝酸氧化下硫酸浸出,钴浸出率为96.35%。     

新疆喀拉通克铜精矿的加压酸浸研究

针对新疆喀拉通克铜精矿进行了加压酸浸工艺研究。通过对影响加压酸浸过程各主要因素的逐因素研究、优化，确定了适宜的热压酸浸工艺条件。在所确定的适宜条件下，取得了Cu浸出率平均96．89％，Ni浸出率平均97．98％，加压酸浸S回收率平均85．65％的良好指标。     

硫铜钴矿生物浸出过程中细菌的作用及其溶解反应途径

研究硫铜钴矿生物浸出过程中细菌的作用及其溶解反应途径。结果表明,间接作用机制和接触作用机制均对硫铜钴矿生物浸出过程产生影响。当细菌吸附到矿物表面时,矿物溶解速率显著加快,说明浸出过程中接触作用机制对硫铜钴矿的溶解有重要影响。浸出过程中硫元素氧化价态的变化顺序为S?2→S0→S+4→S+6,并有单质硫沉淀在矿物表面,说明硫铜钴矿生物浸出过程按照多硫化物途径进行。硫铜钴矿表面被细菌严重腐蚀,出现许多大小不一的腐蚀坑洞,并有单质硫、硫酸盐及亚硫酸盐生成。这些氧化产物在矿物表面形成一层钝化层。     

Study of decomposing carbonyl slag

1 Introduction Carbonyl slag is a kind of solid from the material with nickel by carbonylation. It usually contains Cu, Ni, Co, Fe, S, As, Sb, Au, Ag and platinum metals, and holds great recovery value. At present, with the development of the technology o…     

水钴矿中选择性提取铜和钴的新工艺

针对某水钴矿的特点,采取还原酸浸旋流电积新工艺选择性提取其中的铜和钴。系统考察初始硫酸浓度、温度、时间、Na2SO3用量、液固比等因素的影响,确定浸出最佳条件如下:初始硫酸浓度为75g/L,Na2SO3用量为7%,液固比L/S=4 mg/L,温度为70℃,时间为0.5 h。对浸出液进行了旋流电积提取铜和钴的探索实验研究,得到纯度分别为99.95%、99.97%的电积铜、钴产品,铜、钴的直收率分别达到98.23%和94.54%。     

Extraction of arsenic from arsenic-containing cobalt and nickel slag and preparation of arsenic-bearing compounds

The arsenic extraction from the arsenic-containing cobalt and nickel slag, which came from the purification process of zinc sulfate solution in a zinc smelting factory, was investigated. The alkaline leaching method was proposed according to the mode of occurrence of arsenic in the slag and its amphoteric characteristic. The leaching experiments were conducted in the alkaline aqueous medium, with bubbling of oxygen into the solution, and the optimal conditions for leaching arsenic were determined. The results showed that the extraction rate of arsenic was maximized at 99.10% under the optimal conditions of temperature 140 °C, NaOH concentration 150 g/L, oxygen partial pressure 0.5 MPa, and a liquid-to-solid ratio 5:1. Based on the solubilities of As₂O₅, ZnO and PbO in NaOH solution at 25 °C, a method for the separation of As in the form of sodium arsenate salt from the arsenic-rich leachate via cooling crystallization was established, and the reaction medium could be fully recycled. The crystallization rate was confirmed to reach 88.9% (calculated on the basis of Na₃AsO₄) upon a direct cooling of the hot leachate down to room temperature. On the basis of redox potentials, the sodium arsenate solution could be further reduced by sulfur dioxide (SO₂) gas to arsenite, at a reduction yield of 92% under the suitable conditions. Arsenic trioxide with regular octahedron shape could be prepared successfully from the reduced solution, and further recycled to the purification process to purify the zinc sulfate solution. Also, sodium arsenite solution obtained after the reduction of arsenate could be directly used to purify the zinc sulfate solution. Therefore, the technical scheme of alkaline leaching with pressured oxygen, cooling crystallization, arsenate reduction by SO₂ gas, and arsenic trioxide preparation, provides an attractive approach to realize the resource utilization of arsenic-containing cobalt and nickel slag.     

硬质合金刀具钴和碳化钨的浸出研究

硬质合金刀具在高速切削时,必须使用水基加工液。然而发现使用时水基加工液会使硬质合金中的钴、碳化钨浸出。本文通过浸泡试验,借助于扫描电镜和能谱分析,研究了不同温度时三乙醇胺溶液、碳酸钠溶液和苯并三氮唑溶液对硬质合金刀具中钴和碳化钨浸出的影响。实验结果表明:三乙醇胺溶液对硬质合金刀具中的钴有浸出的作用,常温下钴的浸出率为17.32%,随着温度的升高浸出作用明显,150℃时钴的浸出率为47.72%;碳酸钠溶液对硬质合金刀具中碳化钨有浸出作用,常温下钨的浸出率为13.28%,随着温度的升高,碳化钨的氧化溶解加剧,钨元素的浸出更加明显,150℃时钨的浸出率为45.59%;苯并三氮唑溶液对硬质合金中的钴无浸出作用,对硬质合金中的钨浸出作用不明显,150℃时钨的浸出率为1.28%。     

Extraction of cobalt from laterite ores by citric acid in presence of ammonium bifluoride

Citric acid was used to selectively extract cobalt from limonite-type laterite ores in the presence of ammonium bifluoride. The results show that ammonium bifluoride enhances the leaching of cobalt by citric acid, and 84.5% cobalt is extracted from a laterite ore containing 0.13% Co when leached at ambient temperature for 2 h with 30 g/L citric acid and 10 g/L ammonium bifluoride. Pyrolusite is reduced by citric acid during leaching, cobalt intergrown with which is liberated and subsequently chelated by the citric acid. The extraction of cobalt is enhanced in the presence of ammonium bifluoride because the matrix of silicate minerals is destroyed by ammonium bifluoride and the adsorbed cobalt is subsequently liberated.     

Recovery of Mn^2＋, Co^2＋ and Ni^2＋ from manganese nodules by redox leaching and solvent extraction

The recovery of Mn, Co and Ni from deep-sea manganese nodules was conducted by acid oxidative leaching and solvent extraction. The results indicate that pyrrhotite used during leaching can effectively facilitate the leaching out of manganese, cobalt and nickel. The leaching behaviors of Mn, Ni and Co were determined and the influences of temperature, leaching time and sulphuric acid concentration on leaching rate were also investigated. Co and Ni are precipitated from the leaching liquor by adding sodium sulfide into solution with agitation for 2 h at 50 ℃, and the manganese sulphate is obtained by concentrating the resulting solution. By re-dissolving the precipitates of cobalt and nickel, the separation of cobalt and nickel is performed using di（2-ethylhexyl） phosphoric acid （D2EHPA） for impurities elimination with 8 stages at organic-to-aqueous（O/A） volume ratio of 3：5, and 2- ethylhexyl phosphonic acid mono-2-ethylhexyl ester （known as PC88A or P507） for cobalt extraction with 3 stages counter-current operations at O/A volume ratio of 2：3 followed by their scrubbings and strippings, respectively. The final maximum recovery rates for manganese, cobalt and nickel are 85%, 75% and 78%, respectively.     

Dissolution of lateritic nickel ore using ascorbic acid as synergistic reagent in sulphuric acid solution

The dissolution of nickel and cobalt from Caldag lateritic nickel ore using the combination of sulphuric and ascorbic acids was investigated. The use of other organic acids, namely citric, maleic and stearic acids, as synergistic reagents was studied for comparison. The results revealed that the use of ascorbic and citric acids markedly improved the dissolution of cobalt compared to the other two organic acids that only showed slight synergistic effect on the leaching rate. In terms of nickel dissolution, ascorbic acid is the most effective synergist, followed by citric, maleic and stearic acids in descending order. Under the most optimized conditions found in this study, i.e., using 1 mol/L of sulphuric acid with the presence of 4 g/L of ascorbic acid at 80 °C and solid-to-liquid ratio of 1/10, more than 99% and 98% leaching rates of cobalt and nickel, respectively, can be achieved within 4 h of leaching. In addition, the leaching performance is relatively insensitive to the change of ascorbic acid concentration from 2 to 4 g/L which is highly desirable from operational perspective.     

抑制硬质合金中金属W、Co水解的复合防锈剂研究

采用工业上常用的几种水基加工液防锈添加剂对纯钴片和硬质合金刀具在常温下进行浸泡实验,用纯钴片和钨片做电极与饱和甘汞电极组成原电池测定电动势,根据电动势的大小结合电镜扫描分析判断不同防锈剂溶液对金属Co、W的溶解浸出情况。优选出抑制金属Co、W浸出效果好的防锈剂,将其按不同的比例复配进行电化学测定实验。实验结果表明:苯并三氮唑和钼酸钠对金属Co、W的浸出有明显的抑制作用。