(1. 北京科技大學(xué) 土木與資源工程學(xué)院，北京 100083；
2. 中國科學(xué)院 過程工程研究所 生化工程重點(diǎn)實(shí)驗(yàn)室，北京 100190)
摘 要: 以焦化廢水為還原劑，在硫酸介質(zhì)中利用收縮芯模型研究焦化廢水加壓直接還原浸出軟錳礦的動力學(xué)，考察攪拌速度、反應(yīng)溫度、軟錳礦粒徑、硫酸濃度和焦化廢水CODcr濃度對錳浸出速率的影響。結(jié)果表明：錳浸出率隨反應(yīng)溫度、硫酸濃度、焦化廢水CODcr濃度的增加和軟錳礦粒徑的減小而增大。在393 K~423 K間，焦化廢水還原浸出軟錳礦受固膜擴(kuò)散控制，表觀活化能為15.2 kJ/mol，硫酸和焦化廢水CODcr濃度的表觀響應(yīng)級數(shù)分別為1.21和0.98。機(jī)理分析表明：軟錳礦氧化焦化廢水中大分子有機(jī)物分解成小分子而被還原溶出，或被小分子直接還原溶出；反應(yīng)過程中，軟錳礦表面殘留的Fe、Si、Al形成孔洞薄壁而影響錳的溶出過程。
關(guān)鍵字: 焦化廢水；軟錳礦；還原浸出；動力學(xué)
（1. School of Civil and Resource Engineering, University of Science and Technology, Beijing 100083, China;
2. National Key State Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China）
Abstract:Using the coking wastewater as reducing agent to pressure leaching the pyolusite, the shrinking core model was used to investigate the kinetics of the manganese reductive leaching process in the sulfuric acid solution. The effects of stirring speed, reaction temperature, the particle size of the pyrolusite and the concentrations of H2SO4 and coking wastewater on the leaching rate were investigated. The results show that the leaching of manganese increases with the increase of the temperature, the concentrations of H2SO4 and coking wastewater, whereas decreases with the increase of particle size. The kinetic equation for the manganese pressure reduction is presented at the temperature ranging from 393 K to 423 K, with the apparent activation energy of the leaching process is obtained to be 15.2 kJ/mol and the reaction orders for the concentration of H2SO4 and coking wastewater are 1.21 and 0.98, respectively. It suggests that the reduction of manganese from pyrolusite is controlled by the diffusion through the ash-inert layer. The mechanism analysis shows that pyrolusite is reduced by the multikey macromolecules of coking wastewater through providing the oxygen atom for the macromolecular organic compounds decomposition, or is reduced directly by small organic molecules. The thin-walled with holes superficial layer constituted by residual of Fe, Si, Al affects the Mn leaching.
Key words: coking wastewater; pyrolusite ore; reductive leaching; kinetics
