固态还原铁捕集法从废有机催化剂中回收铑的研究

我国铑资源十分稀少,需求量大,废催化剂资源丰富,开展从废催化剂中回收铑意义重大。提出采用固态铁捕集法从废有机催化剂富集回收铑的工艺,重点研究了还原制度、添加剂、还原剂、捕集剂对铑回收率的影响。结果表明,在还原温度为1200℃,还原时间为6 h,还原剂煤粉配比为9%,添加剂Ca O配比为8%的条件下进行固态还原,还原产物经细磨、摇床分选后获得含铑铁粉,其中铑的含量为106 g/t,回收率为96.53%。     

选择性还原-磁选回收镍渣中的有价金属

采用选择性还原-磁选工艺富集某镍渣中的镍、铜,通过控制还原过程参数实现选择性还原。结果表明：添加熔剂并适当提高渣料的碱度（CaO与SiO2质量比）有助于镍、铜的富集;对碱度0.15、还原温度1200℃、还原时间20 min、内配煤量5%（质量分数）的优化条件下得到的还原样品,通过磨矿-磁选获得镍、铜、铁品位分别为3.25%、1.20%、75.26%的精矿,镍、铜、铁的回收率分别为82.20%、80.00%、42.17%,实现了镍、铜相对于铁的选择性富集;选择性还原-磁选没有显著降低S、P的含量,两者在工艺过程中的行为需要进一步研究。     

含铑树脂中铑的回收工艺研究

采用水溶液氯化法、王水溶解法和水溶液氯酸钠氧化法等3种湿法工艺从含铑树脂中回收铑,重点研究了溶解体系、反应温度、反应时间和液固比等对铑溶解率的影响。结果表明,在液固比12:1 mL/g、反应温度90℃、反应时间20 h的条件下,采用水溶液氯化法铑溶解率达到95%,经精炼后得到合格铑粉,铑的回收率达到92%。     

铜捕集法从失效汽车催化剂中回收铂、钯和铑的研究

采用铜捕集法从失效汽车催化剂中回收铂族金属,重点研究了Ca O/Si O2质量比、捕集剂、熔炼温度和时间、以及还原剂对Pt、Pd和Rh回收率的影响。结果表明,在Ca O/Si O2=1.05,Cu O配比35%~40%,还原剂配比6%,熔炼温度1400℃,熔炼时间5 h的条件下,Pt、Pd和Rh回收率分别为98.2%、99.2%和97.6%。     

铅试金富集-ICP-AES测定催化剂及含铑废水中的铑

用铅试金富集催化剂及含铑废水的铑并用钯作灰吹保护,得到钯、铑合粒。合粒经溶解后,用ICP-AES测定其中的铑。该法的富集效果好,钯基体对测定没有干扰,测定快速、准确,相对标准偏差小于1%(n=7),回收率大于97%。本法可用于含铑0.x%～0.000x%的测定。     

低品位红土镍矿还原-磁选镍铁的实验研究

利用碳还原-磁选工艺回收低品位红土镍矿中的铁和镍。在对矿物成分、物相分析的基础之上,考察还原反应温度、配碳比(C/O)、助熔剂的添加量(Ca O%)和还原时间等因素对Fe、Ni回收的影响,结果表明,还原反应温度1 375℃、配碳比(C/O)0.8、助熔剂的添加量(Ca O%)12%、还原时间300 min的条件下,低品位红土镍矿中镍和铁的回收率分别为99.47%和97.54%,同时尾矿中Ni、Cr含量低于0.04%。     

从合成三(三苯基膦)氯化铑产生的有机废液中回收铑

针对三(三苯基膦)氯化铑合成过程中产生的含铑有机废液的特点,采用火-湿联用工艺成功回收废液中的铑,回收率约达99％.该工艺的主要工序包括:蒸馏回收乙醇和除去水分、焚烧灰化、氯化、净化、氢还原,最终获得纯铑粉.     

废贵金属催化剂中铑回收工艺研究进展

综述了废贵金属催化剂中铑的回收、富集及精炼工艺,对铑回收技术发展前景进行了展望。     

铑催化剂在NBR加氢领域的应用及回收方法

研究了铑催化剂在丁腈橡胶(NBR)均相加氢领域的应用,并开发了一种新的水相萃取回收铑的方法,首次以氯化亚锡为络合剂,2mol/L盐酸为萃取剂,可以很容易从氢化丁腈橡胶(HNBR)胶液中脱除铑催化剂。主要研究反应温度、时间、络合剂用量及萃取剂用量等条件对脱除铑催化剂的影响,在得到铑络合催化剂的最佳脱除条件下,铑催化剂的脱除率可达99%以上。IR以及1HNMR表征表明这种脱除铑催化剂工艺对HNBR的结构无影响,且不影响耐油的CN基团。     

失效汽车催化剂精炼渣中铂族金属的碱焙烧富集

针对难溶解的失效汽车尾气净化催化剂精炼渣,采用碱焙烧-水浸工艺去除渣中的硅和铝,使铂钯铑得到富集。考察了碱用量、焙烧温度、焙烧时间、料层厚度和水浸温度等因素对精炼渣溶解率的影响。结果表明,当碱料比1:1、焙烧温度650℃、焙烧时间3 h、料层厚度4 cm、水浸温度70℃时,精炼渣溶解达到90%以上,富集渣中铂族金属品位提高10倍。     

从有机废料中回收铑的技术进展

有机铑废料中的铑具有很高的价值,且铑资源十分匮乏,从有机废料中回收铑意义重大。目前从含铑有机废料中回收铑的技术主要包括火法工艺、湿法工艺以及其他工艺。火法工艺中焚烧法具有技术简单,铑回收率较高等特点,是目前含铑有机废料回收常用的方法,但焚烧过程温度控制要求比较严格,且存在着环保问题;湿法工艺相对简单,但主要存在铑回收率低等问题;其他工艺尚未得到应用。开发高效清洁的新工艺是今后含铑有机废料回收技术发展的重要方向。     

锌浸渣还原焙烧-磁选回收铁

在查明锌浸渣工艺矿物学的基础上,采用还原焙烧将铁酸锌分解为氧化锌和磁性氧化铁,再通过磁选的方法回收铁,达到锌、铁分离的目的。实验考查了焙烧温度、焙烧时间、还原剂用量对铁酸锌分解率、铁回收率和铁品位的影响。结果表明:在焙烧温度为950℃、焙烧时间为1 h及还原剂添加量为10%和5%的条件下,铁酸锌分解率达到72.05%,铁回收率可达到91.79%,精矿中铁的品位为50%左右。焙烧及磁选过程中颗粒的团聚包裹是铁精矿品位不高的主要原因。     

从废铑催化剂中提取铑粉

介绍了从大庆石化总厂丁辛醇生产装置排出的废铑催化剂回收Rh的工艺流程及其生产方法，包括焚烧、溶解、电解回收、酸洗、焙烧等工序，该回收工艺简单，成本低，Rh总回收率＞95％，所得Rh纯度＞99.5%。     

Recovery of iron from waste ferrous sulphate by co-precipitation and magnetic separation

Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows: n(CaO)/n(Fe²⁺) 1.4:1, reaction temperature 80 °C, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe³⁺ to Fe²⁺ in the reaction solution 1.9–2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.     

Efficient enrichment of nickel and iron in laterite nickel ore by deep reduction and magnetic separation

The process of deep reduction and magnetic separation was proposed to enrich nickel and iron from laterite nickel ores. Results show that nickel–iron concentrates with nickel grade of 6.96%, nickel recovery of 94.06%, iron grade of 34.74%, and iron recovery of 80.44% could be obtained after magnetic separation under the conditions of reduction temperature of 1275 °C, reduction time of 50 min, slag basicity of 1.0, carbon-containing coefficient of 2.5, and magnetic field strength of 72 kA/m. Reduction temperature and time affected the possibility of deep reduction and reaction progress. Slag basicity affected the composition of slag in burden and the spilling and enriching rate of nickel–iron from a matrix to form nickel–iron particles. Nickel–iron particles were generated, aggregated, and grew gradually in the reduction process. Nickel–iron particles can be effectively separated from gangue minerals by magnetic separation.     

加压氢还原法分离铑铱

用加压氢还原分离铑铱,考察了温度、氢压、反应时间、铑铱浓度比和氯离子浓度等因素对选择性还原铑的影响,指出本法可用于从大量铱中分离少量铑。     

Reduction roasting–magnetic separation of vanadium tailings in presence of sodium sulfate and its mechanisms

Reduction roasting with sodium sulfate followed by magnetic separation was investigated to utilize vanadium tailings with total iron grade of 54.90 wt% and TiO_2 content of 17.40 wt%. The results show that after reduction roasting–magnetic separation with sodium sulfate dosage of 2 wt% at roasting temperature of 1150 °C for roasting time of 120 min, metallic iron concentrate with total iron grade of 90.20 wt%, iron recovery rate of 97.56 % and TiO_2 content of 4.85 wt% is obtained and high-titanium slag with TiO_2 content of 57.31 wt% and TiO_2 recovery rate of 80.27 % is also obtained. The results show that sodium sulfate has a catalytic effect on the reduction of tailings in the novel process by thermodynamics, scanning electron microscopy(SEM) and X-ray diffraction(XRD) and reacts with silica and alumina in the tailings to form sodium silicate and sodium aluminosilicate. Migration of elements and chemical reactions destroy the crystal structures of minerals and promote the reduction of vanadium tailings, resulting in that iron grains grow to large size so that metallic iron concentrate with high total iron grade and low TiO_2 content is obtained.     

Recovery of iron from Baotou rare earth tailings by magnetizing roast

The difference of physicochemical properties among minerals in Baotou rare earth tailings is not significant,which leads to a great difficulty in separation of minerals.In this article,the process of magnetizing roast and low-intensity magnetic separation was used to recover iron.Effect of calcination temperature,holding time and carbon/oxygen ratio on roasting efficiency was investigated.The parameters evaluating magnetizing roast efficiency and theoretical value were determined.X-ray diffraction(XRD)analysis was used to investigate the conversion of Fe phase after roasting.The results show that the best magnetizing roast conditions are calcination temperature of 650℃,holding time of 2.5 h,and carbon/oxygen molar ratio of 3.85.The best magnetization rate is 2.36,which is close to the theoretical value of 2.33.Based on experiments of low-intensity magnetic separation under different intensities,the best current intensity is 2.0 A to obtain the best separation results.Under the best condition,the concentrate grade of iron is 45.45% and the recovery of iron is 68.36%.Most of rare earth,fluorine,and phosphorus are enriched in the magnetic separation tailings.The XRD analysis shows that Fe exists in Fe2O3 before roasting and exists in Fe3O4after roasting.