【作者】 戴艳阳；

【导师】 钟海云；

【作者基本信息】 中南大学 ， 冶金工程， 2013， 博士

【摘要】 摘要：我国现行钨冶炼工艺以湿法碱处理为主,几乎所有的钨碱浸渣(以下称钨渣)中都含有少量的W、Fe、Mn、Ta、Nb、Sc等有价金属,目前我国堆存的钨渣已近100万吨,具有较大的综合回收价值。然而,目前对钨渣的处理基本上还停留在简单回收钨、钪的阶段,而对钽、铌等均未进行回收。本论文针对目前钨渣的特点,以高钙高硅低钨含量的钨渣为原料,研究了钨渣湿法处理回收钨、富集钽铌、锰锌软磁铁氧体粉末制备,开发了从钨渣中综合回收钨、钽、铌、铁、锰等多种金属的新清洁工艺,分析了该工艺过程中的放射性污染和三废处理,得出以下主要结论：系统研究了钨渣中钨的回收工艺及提高钨回收率的新方法。详细考察了钨渣的工艺矿物学特征,比较了各工艺因素对钨回收率的影响。结果表明：酸法处理钨渣时钨分散在固液两相中,钨浸出率最高达到79.2%,但酸浸液成分复杂,回收效果不佳；碱法处理时采用预焙烧-水浸工艺,浸出液杂质含量低,含钨浸出液的循环利用有利于提高钨回收率,浸出液经三次循环后钨含量可达到16.6g·L-1,钨的总回收率达到88%以上对钨渣中钽、铌的富集行为进行了较系统的研究。比较了钨渣的盐酸直接处理工艺、硫酸溶液直接处理工艺、浓硫酸焙烧-络合浸出工艺、苏打烧结-水浸出工艺、酸碱混合处理工艺中钽、铌的富集行为和回收率。研究表明：钽、铌盐类在酸、碱溶液中的溶解度不同导致钽、铌的回收率和富集效果的差异；钨渣低温低酸度酸处理时钽、铌的回收率最高可分别达到80.1%、72.3%,而高温高酸度处理可以得到∑(Ta2O5+Nb2O5)含量达到5.34%的富集物；浓硫酸焙烧-络合浸出法则获得了∑(Ta2O5+Nb2O5)含量达到13.03%的钽铌富集物,可以直接作为钽铌冶炼原料；酸碱混合处理所得钽铌富集物∑(Ta2O5+Nb2O5)含量比钨渣直接酸或碱处理均有所提高,但总的金属回收率降低；酸碱混合处理过程中,酸碱处理顺序对钽铌的富集行为有一定的影响；碱处理过程中少量钽、铌进入溶液。首次以钨渣为原料制备了锰锌软磁铁氧体粉末,实现了铁锰资源的高值化利用。提出了钨渣“硫酸浸出-溶液净化-共沉淀-烧结”制备锰锌软磁铁氧体粉的工艺,结果表明：制备的锰锌软磁铁氧体粉末主金属配比接近理论配比,杂质元素的含量低,其中硅0.023%,钙0.021%,镁0.027%,满足软磁铁氧体粉末的要求；而且通过对共沉淀前液的成分调控,可获得各种不同配方的软磁铁氧体粉末。研究了从钨渣中回收制备四氧化三锰的新工艺。采用两段硫酸化焙烧法分离钨渣中的铁、锰,钨渣与质量分数为50%硫酸混合后在200℃温度下焙烧60min,然后升温至700℃温度下焙烧120min,焙烧产物经水浸出获得含锰溶液,溶液中锰铁质量比达到3000以上,铁浸出率仅为0.01%,分离效果良好。含锰溶液经净化、水解沉锰、H202氧化,获得粒度小于0.1μm的超细四氧化三锰粉末,产品质量的主要指标基本达到HG/T2835-1997标准。研究了钨渣中有价元素综合回收清洁工艺。研究表明：采用苏打烧结-水浸出-硫酸浸出-浸出液净化-共沉淀-烧结工艺可以有效综合回收钨渣中的钨、钽、铌、铁、锰,各金属的总回收率分别为88.1%、78%、56%、95.2%、68.5%。对工艺过程放射性及三废处理的研究表明：钨渣属于极低放射性固体废弃物,处理过程中放射性元素主要集中在富集钽铌的硫酸浸出渣中,富集渣总比放18556Bq/Kg,可直接用于钽铌冶炼。该工艺三废量少,易于处理,较好地实现了钨渣的清洁处理,不仅回收利用了工业废料,同时还提供了新的锰资源来源。图73幅,表67个,参考文献136篇。更多还原

【Abstract】 Abstract:Wet processing are mainly used in tungsten metallurgy. Almost all of basic leached residue from tungsten concentrate (hereinafter referred to as the’tungsten residue’) contains a small amount of valuable metals such as tungsten, iron, manganese, tantalum, niobium, scandium, and so on. For the present, piled tungsten residues with a total capacity of nearly one million tons may have greater value of comprehen-sive recovery. The present treatments of tungsten residue mainly focuse on the recovery of tungsten and scandium, while tantalum and niobium are neglected.According to the characteristics of tungsten residue, hydrometallurgi-cal recovery of tungsten, concentration of tantalum and niobium and preparation of manganese-zinc ferrite powder were investigated by using tungsten residues with high calcium and silicon and lower tungsten as the raw material. A new clean process involving comprehensively covery of tungsten, tantalum, niobium, iron and manganese from tungsten residue was developed. And radioactive contamination and "three wastes" treatment of the technology were analyzed. The main conclusions derived from this study are:The recovery process of tungsten from the residue and the way to increase its recovery were systematically investigated. The characteristics of the technological mineralogy of tungsten residue was in detail inspected. And the impacts of several technical factors on the tungsten recovery were compared. Tungsten scattered in both solid and liquid during acid processing and the recovery of tungsten topped out at79.2%. However, it’s difficult to obtain product due to the complex composition of acid leaching solution. Using the process of preroasting-water leaching, leach liquor contains low contents of impurities. It is found that recycling of tungsten bearing leach liquor benefit the increases of tungsten recovery. The amount of tungsten in the solution may reach16.6g·L-1and total recovery of tungsten may over88%after three cycles.The enrichemnt of tantalum and niobium from tungsten residue was systematically studied. Enriching behaviors and recoveries of tantalum and niobium were compared in the technologies such as hydrochloric acid treatment directly, leaching directly by sulfuric acid solution, concentrated sulfuric acid roasting and complexation leaching, the technology of soda sintering and water leaching, combining acid&alkaline process. According to the experimental results, the different solubilities of tantalum and niobium salts in the acid and alkaline solution led to differences of the enrichment effect and recoveries. Recoveries of tantalum and niobium ran up to80.1%and72.3%respectively as the tungsten residue was processed at low temperature and low acidity. Concentrate carried Ta2O5and Nb2O5with the total content as5.34%can be gained at high temperature and high acidity. And concentrate with the total content of Ta2O5and Nb2O5as13.03%was gained via process involving concentrated sulfuric acid roasting and complexing leaching, which could be used as the feed for tantalum and niobium metallurgy. The total content of Ta2O5and Nb2O5in concentrate from the combining technology was higher than acid treatment or alkaline treatment directly, while the overall recovery decreased. The application sequence of the acid and alkaline in the combining technology had some effects on the enriching behavior of tantalum and niobium. Few tantalum and niobium turned into solution when alkaline treated.Preparation of manganese-zinc ferrite powder from tungsten residue has been studied for the first time, which comprised high-value utilization of manganese and iron. Process of manganese-zinc ferrite powder prepara-tion involving leaching by sulfuric acid, purification of leaching liquor, coprecipitation and sintering has been investigated. The experimental results demonstrated that proportion of main metals in manganese-zinc ferrite powder near the theoretical value and the powder has low contents of impurities, for instance, silicon0.023%, calcium0.021%, magnesium0.027%, which can meet the quality requirements of manganese-zinc ferrite powder. Manganese-zinc ferrite powder with different ingredients may be obtained by compositional controlling of liquor before coprecipita-tion.Process of the preparation of manganic manganous oxide from tungsten residue has been investigated. Two-stage sulphating roasting was adopted to separate manganese from iron. The tungsten residue&50%sulfuric acid mixture was roasted at200℃for60min and then the temperature is raised to700℃and keep120min. Manganese beraing solution, in which mass ratio of manganese and iron could reach more than3000, was gained by water-leaching and the leaching efficiency of iron was only0.01%. The results show good separation of manganese and iron. Ultrafine manganic manganous oxide powder with particle size of less than0.1μm was prepared by means of purification of solution, neutralization and precipitation of manganese and oxidation of hydroxide by H2O2. The major product quality indexes basically can meet the enterprise standard (HG/T2835-1997).The clean process involving comprehensively recovery of valuable metals in tungsten residue was developed. Investigation shows that tungsten, tantalum, niobium, iron and manganese could be recovered effectively from tungsten residue via the technology composed of soda sintering, sulfuric acid leaching, liquor purification, coprecipitation and sintering procidure. And the total recoveries of tungsten, tantalum, niobium, iron and manganese weres reported to88.1%,78%,56%,95.2%,68.5%respectively. According to researches on the radioactivity and three-wastes treatment during comprehensive recovering procee, the radioactive elements were distributed in many kands of products, mainly in the leach sludge from sulfric acid processing with a specific radioactivity as18556Bq/Kg, which meets discharge standards and may be used in tantalum and niobium metallurgy. The technology has better achieved clean processing of tungsten residue due to less three wastes which are easily disposed. It not noly recycled industrial wastes but also opened new doors for manganese resource ferrite industry via its production from tungsten residue. There were73figures,67tables and136references.更多还原