(1. 江西理工大學(xué) 材料冶金化學(xué)學(xué)部，贛州 341000；
2. 江西理工大學(xué) 贛州市綠色冶金與過(guò)程強(qiáng)化工程技術(shù)研究中心，贛州 341000)
摘 要: 在離子型稀土浸出液氧化鈣沉淀過(guò)程中，硫酸根會(huì)參與反應(yīng)產(chǎn)生堿式硫酸稀土，使所得混合稀土氧化物中硫酸根含量過(guò)高。針對(duì)這一問(wèn)題，本文基于競(jìng)爭(zhēng)配位除硫的思路提出采用丙二酸鈉對(duì)氧化鈣沉淀富集物進(jìn)行攪洗以除去其中的硫酸根，在攪洗反應(yīng)溫度45 ℃，攪洗時(shí)間10 min，丙二酸鈉溶液濃度0.10 mol/L、體積30 mL的條件下，獲得了稀土純度為91.36%、硫酸根含量為3.02%(質(zhì)量分?jǐn)?shù))的混合稀土氧化物。通過(guò)對(duì)反應(yīng)過(guò)程的質(zhì)量衡算和TG-DSC、XRD、FI-IR等測(cè)試表征，確定了在攪洗過(guò)程中丙二酸根與堿式硫酸稀土中的硫酸根以摩爾比1:1競(jìng)爭(zhēng)配位。丙二酸根的引入可有效降低硫酸根含量，但是其攪洗循環(huán)效果有待進(jìn)一步提高。
關(guān)鍵字: 離子型稀土礦；氧化鈣；混合稀土氧化物；丙二酸根；硫酸根
（1. Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. Ganzhou Engineering Technology Research Center of Green Metallurgy and Process Intensification, Jiangxi University of Science and Technology, Ganzhou 341000, China）
Abstract:The process of calcium oxide precipitation enrichment can be linked to the magnesium salt composite leaching technology to realize the circulation of calcium and magnesium, in turn, solve the ammonia nitrogen problem in the ionic rare earth ore processing, including leaching and enriching. However, sulfate will participate to form basic rare earth sulfate in the precipitation process, resulting in a high content of sulfate radical in the roasted product. As continuation of the idea of desulfurization by competitive coordination, this paper proposes to remove sulfate radical from the calcium oxide precipitation enrichment in the stirring washing process using malonate as exchanged ligand. Mixed rare earth oxides with rare earth purity of 91.36% and sulfate content of 3.02% (mass fraction) are obtained at 45 ℃ and the washing time of 10 min, sodium malonate concentration of 0.10 mol/L and sodium malonate volume of 30 mL. 1:1 coordination of the malonate and the sulfate in the basic rare earth sulfate during the stirring washing process is determined by the mass balance calculation of the reaction process and the characterization of TG-DSC, XRD, FI-IR, etc. The content of sulfate radical can be effectively reduced by exchanging with malonate, but its cycle stability needs to be further improved.
Key words: ionic rare earth ore; calcium oxide; mixed rare earth oxides; malonate; sulfate
