Comprehensive Utilization Of Complex Rare Earth Metals Mine

With the rapid development of information industry, energy resources industry andmicroelectronics technology, and the increasing demand for rare earth resources provides anexcellent opportunity for the development of rare earth metallurgical technology. The researchdevelopment of the rare earth, tantalum-niobium, beryllium mineral resources is summarized.The basic study on the complex utilization of valuable metals in low-grade refractoryassociated resources containing rare earth, tantalum-niobium and beryllium resource is carriedout to resolve the difficulty of separation and leaching of low-grade refractory associatedresources with rare earth, tantalum, niobium and beryllium. New ways of clean and efficientextraction metallurgy is achieved to get the efficient utilization of rare earth,tantalum-niobium and beryllium mineral resource.In this paper, the comprehensive utilization of the valuable metals(rare earth,tantalum-niobium and beryllium) in the rare earth concentrate of Baer Zhe deposit (801mines)(rare earth20to30%, tantalum-niobium about3%, beryllium3%) is researched and thefollowing conclusions are obtained:1. The effects of different process conditions: sulfuric acid amount, activator dosage,calcination temperature and roasting time on the leaching rate of rare earth, tantalum-niobiumand beryllium are studied; the composition and properties of tantalum-niobium sulfate areanalyzed. The researches show that: weighing1kg of rare earth concentrates, mixed withconcentrated sulfuric acid1L and activator250g, curing for1h after uniform mixing, and thencalcined at260℃for6h, whisking and leaching the product with7.5L water for2h, afterfiltration and washing,8L rare earth concentrate leaching solution is collected, and theleaching rates of rare earth, niobium and beryllium are97.8%,90.3%and99%, respectively.2. The processing conditions of the separation of rare earth, tantalum-niobium andberyllium with oxalate precipitation are studied; the hydrolysis properties ofniobium(tantalum) oxalate complexes under different pH conditions are researched. Theresults show that:(1) After1kg oxalic acid is added into the8L rare earth concentrate leaching solution, the pHvalue is adjusted with sodium carbonate to1.5~2.0, and the precipitation rate of rare earth is97.3%, the precipitation rate of (Ta+Nb) is less than5%, and almost no precipitation ofberyllium is obtained; rare earth oxides is achieved after the firing of rare earth oxalateprecipitation with the rare earth grade of91.0%, the straight yield of96.1%;(2) In the mother liquor of oxalic acid precipitation, the sodium carbonate is slowly added to adjust the pH value, the tantalum-niobium hydrolyzed precipitates are obtained afterhydrolyzing for3h at90℃, pH4.2, and the precipitation rate of (Ta+Nb) is94%, theprecipitation rate of beryllium is about5%; after drying, the tantalum and niobiumprecipitates are mixed with carbon dust (10%), and then roasted under reduction atmosphereat650℃for3h, the calcined material is dissolved with2L dilute sulfuric acid (15%) toremove iron, and the tantalum-niobium oxides are obtained, the tantalum-niobium grade is25.0%, with the direct yield of78%.3. A new beryllium naphthenic acid extraction system is developed, and the effects ofextraction process conditions on the beryllium extraction and purification are studied. Theresults show that:(1) The beryllium in the niobium mother liquor is hydrolyzing extracted with a naphthenate(O: A=3:1), the pH value is adjusted to6.5with continuous addition of (1+1) aqueousammonia solution, the extraction rate of beryllium is greater than98%;(2) Load naphthenate is acid pickled with sulfuric acid (3N, O: A=6:1) twice, theconcentration of iron, aluminum impurity in the organic phase is less than0.01g/L, theelution loss rate of beryllium is about10%;(3) After the removing of impurities,89.5%beryllium is separated by six stagecountercurrent extration with sodium hydroxide solution (6N, O: A=2:1) in the loadnaphthenic acid, high-purity sodium beryllium is obtained with the direct yield>75%.