(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 以燕麥秸稈為還原劑，在硫酸介質(zhì)中直接浸出某低品位軟錳礦，研究浸出過程的工藝條件和動(dòng)力學(xué)。結(jié)果表明：在硫酸濃度為150 g/L、液固比為9 mL/g、麥稈與軟錳礦質(zhì)量比為0.3、浸出溫度90 ℃、浸出60 min的條件下，錳浸出率可達(dá)96.1%，此時(shí)，鐵浸出率為46.8%，浸出液化學(xué)需氧量(COD)值為6.2 g/L。動(dòng)力學(xué)研究表明：錳的浸出過程在333~363 K內(nèi)符合未反應(yīng)核縮減模型，浸出過程主要受界面化學(xué)反應(yīng)步驟控制，其浸出表觀活化能為69.4 kJ/mol。
關(guān)鍵字: 軟錳礦；燕麥秸稈；還原浸出；動(dòng)力學(xué)；COD
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The extraction of manganese from low-grade pyrolusite ore was investigated using oat straw as a reducing agent in dilute sulfuric acid medium. The optimal conditions and the kinetics from manganese dioxide ores by reductive leaching were discussed. The results show that the leaching rate of manganese reaches 96.1% while the iron dissolved is 46.8% and chemical oxygen demand (COD) is 6.2 g/L under the optimal condition as follows, H2SO4 concentration of 150 g/L, liquid-to-solid ratio of 9 mL/g, mass ratio of oat straw to pyrolusite ore of 0.3, leaching time of 60 min at 90 ℃. The kinetics studies indicate that the leaching process follows the shrinking-core model in the temperature ranging from 333 K to 363 K, the leaching rate of manganese is controlled by the interface chemical reaction during the leaching process, and the apparent activation energy is 69.4 kJ/mol.
Key words: pyrolusite ore; oat straw; reductive leaching; kinetics
