低品位钼镍焙烧矿常压同时浸出钼镍的工艺研究

以低品位的钼镍矿石为原料与CaO混合高温焙烧,所得焙烧矿采用常压氨-碳铵浸出,对同时浸出镍和钼的工艺条件进行了研究。探讨了温度、液固比、浸出时间、碳酸铵的用量等因素对钼和镍浸出率的影响。结果表明,在浸出温度45℃,液固比4∶1(mL/g),浸出时间24h,碳酸铵用量w((NH4)2CO3)∶w(焙烧矿)=0.3的最佳浸出条件下,钼和镍的浸出率分别为94.0%和90.1%。     

高碳镍钼矿制备钼酸铵

研究了高碳镍钼矿制备钼酸铵的工艺,通过氧化酸浸分离镍、钼,制得高品位的钼酸浸出渣。通过单因素、正交实验以及优化实验的探究,确定了氨浸的最佳工艺参数：液固比3∶1,反应温度60℃,反应时间2 h,氨的过量系数为1.6,碳酸氢铵与钼的质量比为0.1,钼的浸出率达98%以上。将氨浸液调节pH、搅拌、加晶种、陈化后析出浅绿色的钼酸铵晶体,产品质量符合GB/T 657-1993标准,钼的总产率达90.67%。     

综合利用镍钼矿提取镍钼的工艺研究

采用酸性氧化预处理—氧化浸出工艺对镍钼矿进行了浸出回收,并确定了各阶段的主要工艺参数。原矿先进行酸性氧化预处理去除碳,NaClO3用量为原矿质量的11%,硝酸浓度为1.0mol/L,90℃下反应1.5h后,再进行氧化浸出,其中H2O2的量为原矿质量的9%,液固比为4∶1,60℃下浸出1.5h。钼的浸出率可达99%左右,镍的浸出率在94%以上。     

从红土镍矿镍铁渣中分离浸取镍铬工艺

将镍铁渣破碎、球磨后磁选富集Ni于精矿中,富集Cr于尾矿中. 磁选后Ni从0.26%富集至2.57%(w),Cr从4.55%富集至4.61%(w). 考察了H2SO4常压酸浸精矿时Ni的浸出规律. 结果表明,在酸浸温度110℃、酸浓度220 g/L、酸浸时间2 h、液固质量比5的优化酸浸条件下,Ni浸出率为91.5%. 在80~120℃内,Ni浸出反应活化能为19.6 kJ/mol. Ni浸出反应主要受扩散控制. 用Na2CO3碱熔焙烧尾矿,在温度1000℃、Na2CO3/渣质量比0.65、时间1 h、镍铁渣尾矿粒度<74 mm的优化条件下,Cr浸出率为94.1%.     

从镍精矿中提取镍铁合金的还原工艺

以镍含量为19.5%的镍精矿为原料,采用氧化焙烧-氢气还原-磁选分离的方法制备了镍铁合金粉. 单因素实验表明,增加还原温度和还原时间以及氧化产物平均粒度在2.25 mm左右均有利于镍铁品位的提高,而增加氢气流量不利于镍铁品位的提高. 设计L9(34)正交实验,确定了最佳工艺条件：还原温度900℃,还原时间8 h,氢气流量1.784 mL/s,氧化产物平均粒度2.25 mm. 利用此方法制备出镍品位56.8%、镍铁含量93.2%的镍铁合金粉,Ni回收率为87.0%.     

硫化叶菌对镍钼硫化矿的浸出作用

对金属硫叶菌浸出镍钼硫化矿进行了研究. 结果表明,有菌组镍的浸出率均在90%以上,而无菌组为77.64%;驯化菌比非驯化菌的浸出率高,前者镍和钼的浸出率分别为94.7%和70.2%,后者为93.1%和68.4%;pH为2时浸出效果最佳,镍浸出率达100%,钼浸出率为66.97%;粒径<0.048 mm和<0.077 mm的浸样镍浸出率均达到100%,钼浸出率分别为68.4%和64.5%;低矿浆浓度比高矿浆浓度的浸出率高,5 g/L矿浆镍和钼的浸出率分别达100%和87.29%;在无菌条件下,浸样添加0.5 g/L Fe3+和对照组的镍浸出率分别为92.8%和76.6%,钼浸出率为52.56%和49.34%;嗜热菌(金属硫叶菌)比常温菌(氧化亚铁硫杆菌)的浸出率高,前者镍钼浸出率分别为93.17%和73.52%,后者为67.34%和38.36%.     

高镁贫镍红土矿煤基还原制备镍铁合金

以含Ni 0.82%、含MgO 31.49%的高镁贫镍红土矿为原料,采用煤基直接还原熔炼方法制备镍含量高于7%的镍铁合金,对产物进行了表征,通过正交实验确定了最优工艺条件.结果表明,原矿主要由蛇纹石、石英和氧化镁组成,81.49%的镍元素取代镁或以吸附态分布于蛇纹石中.温度高于1500℃熔炼过程才能顺利进行.通过L_9(3~3)正交实验确定的最优工艺条件为:熔炼温度1600℃,配碳比C/O=2.0,焙烧时间45 min.该条件下制备出了镍品位7.19%、镍铁含量84.23%的球状镍铁合金,Ni回收率为82%.     

单宁酸-硫酸体系浸出氧化锰矿中锰的研究

为探究单宁酸作为还原剂在硫酸体系中浸出还原低品位软锰矿中锰的可行性,通过单因素实验考察了单宁酸用量、反应时间、反应温度、硫酸浓度等因素对锰浸出率的影响。基于单因素实验结果,通过响应曲面法对工艺参数进行了进一步优化。研究结果表明,在单宁酸用量为3倍理论量、反应时间为3 h、硫酸浓度为1.5 mol/L、反应温度为90 ℃条件下,锰矿中锰的浸出率达到90.86%。反应参数对锰浸出率的影响由大到小的顺序依次为反应温度、单宁酸用量、反应时间、硫酸浓度。该工艺具有锰浸出率较高、硫酸初始浓度低的特点。     

木薯酒糟还原浸出低品位软锰矿工艺研究

用木薯酒糟作还原剂,在硫酸水溶液中浸出低品位软锰矿。通过正交实验和单因素实验,考察了硫酸浓度、反应温度、反应时间和木薯酒糟用量等因素对锰浸出率的影响。结果表明,各因素影响锰浸出率大小的顺序为：硫酸浓度、反应温度、反应时间和木薯酒糟用量。木薯酒糟还原浸出低品位软锰矿适宜条件：硫酸浓度为3.13 mol/L、反应温度为90 ℃、反应时间为3 h、木薯酒糟与软锰矿质量比为0.3。在此条件下,锰的浸出率达到94.8%。     

镍钴锰三元素氢氧化物废料循环回收的工艺研究

实验采用了还原浸出的循环回收处理方法,从镍钴锰三元素氢氧化物废料中重新回收钴、镍和锰,可直接用于重新制备镍钴锰三元素氢氧化物产品,实现废料的循环回收利用。本文研究了还原回收镍钴锰三元素氢氧化物废料的还原剂种类、用量比、反应条件等影响因素对镍、钴和锰元素的回收率的影响。实验结果表明:工艺最佳条件是水合肼是回收镍钴锰三元素氢氧化物废料的最佳还原剂,还原剂用量为1.4倍理论量,反应初始酸度为4 mol·L~(-1),反应温度为50℃,反应液固比为4︰1,反应时间为90 min。钴、镍和锰的回收率分别可达到99.31%、99.75%和99.80%。本工艺简单可行,回收率高,因此适合应用于工业生产。     

硫化钼镍矿加碱焙烧后钼镍的回收率分析

通过焙烧、水浸实现了原生硫化镍钼矿中镍和钼的分离,得到的较优工艺条件为:焙烧时,原矿和无水碳酸钠质量比1:0.9、560℃焙烧6h,650℃焙烧1.5h,焙砂中镍品位为2.67%,钼品位为5.81%;在固液比1:4,温度95℃的条件下,水浸焙烧渣2h,98.21%的镍留在滤渣中,95.43%的钼进入滤液,有效地实现了钼...     

红土镍矿浸出液除杂制备氢氧化镍

以低品位硅镁型红土镍矿硫酸浸出液为原料,用黄钠铁矾[Na2Fe6(SO4)4(OH)12]除铁、NaF除镁、中和沉镍,考察了不同因素的影响。结果表明,添加4 mL/L双氧水对浸出液氧化预处理、用Na2SO4为除铁钠源、控制溶液pH为1.6?2.2、反应时间1.5 h的条件下,铁去除率达92.1%,镍损失率为6.7%,滤渣主相为Na2Fe6(SO4)4(OH)12;除铁后滤液用NaF除去镁离子,最优条件为搅拌速率300 r/min、溶液pH=5.5?6.0及NaF 用量25 g/L,镁去除率达90.9%,镍损失率为6.8%;除杂后净化液用中和水解法提镍,在室温下添加8 g/L NaOH为沉镍剂,中和沉镍提取率达95.1%,得到纯度99.5%的Ni(OH)2产品,镍的综合回收率为82.70%。     

An EXAFS investigation of molybdate-based conversion coatings

The composition of molybdate-based conversion coatings on zinc–nickel alloy electrodeposits was examined by extended X-ray absorption fine structure (EXAFS). The absorption spectra from appropriate standards showed distinct differences between the Mo(IV) and Mo(VI) oxidation states. A pre-edge peak was apparent for the various molybdate species and molybdenum trioxide, with the energy and intensity dependent on the coordination of the molybdenum. A shift in the molybdenum K-edge spectra was also evident between Mo(IV) and Mo(VI) compounds. A qualitative analysis revealed that both Mo(IV) and Mo(VI) species were present within the molybdate-based conversion coating, with a significant prevalence of hexavalent molybdenum.     

机械活化辅助浸出硫化镍矿中有价金属

随着高镍三元锂电池在新能源电动汽车领域的规模化应用,全球镍资源的需求量日益增加,绿色、高效、低成本地从硫化镍矿资源中提取镍的技术备受关注。本工作提出了机械活化辅助氧化浸出硫化镍矿的提取路径,在机械活化过程中通过改变硫化镍矿结构、增加晶体无序化程度、减小粒度和增加比表面积增加硫化镍矿的反应活性,再通过Na2S2O8氧化浸出实现了常压环境中硫化镍矿中有价金属的高效浸出。考察了机械活化和浸出过程中各因素对硫化镍精矿浸出的影响,确定了较优条件。在较优条件球磨转速613 r/min、球料比20:1、球磨时间120 min、酸浓度2 mol/L、过硫酸钠浓度0.42 mol/L、浸出时间60 min、液固比5:1、搅拌速率400 r/min和浸出温度80℃下,Ni, Co, Cu和Fe的浸出率分别达98.9%, 97.7%, 98.2%和98.7%。     

Kinetic correlations in codeposition of coatings of molybdenum-iron group metal alloys

Electrodeposition of Ni-Mo and Fe-Mo alloy coatings from acid citrate electrolyte was investigated over a wide range of cathode potentials and under various hydrodynamic conditions. Such alloys had been found to be deposited with substantial depolarization against iron group metals. With the same electrodeposition conditions, the molybdenum percentage in Fe-Mo coatings is much higher than in Ni-Mo. The molybdenum presence results in a lower overvoltage of hydrogen evolution, so that these alloys are deposited with a current efficiency much lower than that in the separate reduction of iron group metals. For a Ni-Mo system, the Mo percentage in the coating is increased together with increase of the transport rate of ions towards the cathode and with decrease of the cathode potential value being reduced; while for Fe-Mo alloy an inverse relation is observed. When passing from the Ni-Mo to the Fe-Mo system, the control of the molybdenum reduction reaction is changed. In codeposition with nickel it shows a diffusion control, while in discharging with iron its control is of the activation type. The Ni-Mo coatings obtained contained from 1.5–6% molybdenum whereas Fe-Mo deposits contained from 12–40% depending on electrolysis conditions. The quality of the coatings containing more than 20% Mo deteriorated and in these deposits some nonmetallic inclusions were present.     

常压氯化铵焙烧法提取镍磷铁中的镍

采用氯化铵焙烧法处理福泉磷肥厂的镍磷铁并提取其中的镍,研究氯化铵与镍磷铁矿质量比、焙烧温度、焙烧时间等工艺条件对镍磷铁矿氯化焙烧浸出效果的影响。结果表明:当焙烧温度为773 K、焙烧时间为15 min、氯化铵与矿料质量比为0.8∶1.0时,镍在常温下水浸5 min的浸出率为86.19%。     

从加氢失活催化剂中提取有效金属的研究

研究了从负载有钨、钼、镍的加氢失活催化剂中提取有效金属钨、钼、镍的工艺方法。结果表明采用空气焙烧-氨水浸取的方法提取钨、钼,在适宜的条件下提取率能分别达到92.56%、95.03%;以硝酸镍的形式回收镍,镍的回收率能达到66%以上。     

Ni-Mo alloying of nickel surface by alternating pulsed electrolysis using molybdenum(VI) baths

Electrochemical Ni-Mo alloying of the surface of a nickel substrate was investigated using alternating pulsed electrolysis in an aqueous solution containing only molybdate ions (MoO₄²⁻) as a metal ion component. In this electrochemical process, the nickel substrate was slightly dissolved during the anodic pulses, providing nickel ions into the solution in the vicinity of the substrate, while Ni and Mo were both electrodeposited on the substrate surface during the subsequent cathodic pulses. Through the optimization of anodic and cathodic conditions independently based on a set of direct-current electrolysis data, amorphous Ni-Mo alloy layers were found to be formed at the surface of the nickel substrate by the alternating pulsed electrolysis using the MoO₄²⁻ solution of pH 3.0-5.0. The conditions for Ni-Mo alloy formation were discussed in terms of the dissolving regime of ionic species in the electrolytes determined by an equilibrium calculation.