(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083； 2. 有色金屬資源循環(huán)利用湖南省重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083； 3. 有色金屬資源循環(huán)利用湖南省工程研究中心，長(zhǎng)沙 410083)
摘 要: 以粗鉍堿性精煉過(guò)程中產(chǎn)生的碲渣為研究對(duì)象，采用Na2S浸出-Na2SO3還原的新工藝選擇性分離回收碲。考察Na2S濃度、浸出溫度、浸出時(shí)間和液固比等工藝參數(shù)對(duì)碲浸出率的影響，以及Na2SO3過(guò)量系數(shù)、反應(yīng)溫度和反應(yīng)時(shí)間等因素對(duì)碲還原率的影響。結(jié)果表明：在Na2S濃度40 g/L、浸出溫度50 ℃、浸出時(shí)間1 h、液固比8的條件下，碲的浸出率達(dá)87.77%；在Na2SO3過(guò)量系數(shù)2.0，反應(yīng)溫度30 ℃，反應(yīng)時(shí)間30 min條件下，碲還原率達(dá)98.84%，還原產(chǎn)物中碲含量達(dá)97.34%，XRD結(jié)果顯示其為單質(zhì)態(tài)碲。Na2S浸出-Na2SO3還原新工藝可以有效地分離回收碲渣中碲，實(shí)驗(yàn)過(guò)程簡(jiǎn)單、清潔，生產(chǎn)成本低，具有產(chǎn)業(yè)化前景。
關(guān)鍵字: 碲渣；分離；回收；新工藝；浸出率
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China; 2. Hunan Key Laboratory of Nonferrous Metal Resources Recycling, Changsha 410083, China; 3. Hunan Engineering Research Center of Nonferrous Metal Resources Recycling, Changsha 410083, China）
Abstract:A novel process, including sodium sulfide leaching and sodium sulfite reduction, was proposed to selectively separate and recover tellurium from tellurium slag, which came from basic refining of bismuth crude. The effects of Na2S concentration, leaching temperature and time, liquid to solid ratio on leaching efficiency of tellurium, and Na2SO3 multiple of stoichiometric, reacting temperature and time on reduction efficiency of tellurium were investigated. The results show that the leaching efficiency of tellurium reaches 87.77% under the conditions of Na2S concentration 40 g/L, leaching temperature 50 ℃, leaching time 1 h, L/S 8, and the reduction efficiency of tellurium reaches 98.51% under the conditions of Na2SO3 multiple of stoichiometric 2.0, reacting temperature 30 ℃, reacting time 30 min. The content of tellurium in the reduction product reaches 97.34%, and the XRD results show that reduction product is a single Te element phase. Tellurium can be effectively extracted and recovered from tellurium slag by sodium sulfide leaching and sodium sulfite reduction. The process is simple, clean and low cost, which is promising for industrialization in the future.
Key words: tellurium slag; separation; recovery; novel process; leaching efficiency
