【作者】 朱晓帆；

【导师】 张允湘；

【作者基本信息】 四川大学 ， 化学工艺， 2002， 博士

【摘要】 利用软锰矿进行烟气脱硫，不仅可脱除烟气中低浓度SO₂，还可副产品具有工业价值的MnSO₄。本文采用空气（或氮气）和纯SO₂气体按一定比例混合成模拟烟气，用清水配制软锰矿浆，模拟烟气连续通过喷射鼓泡反应器进行吸收，考察该设备和工艺的脱硫浸锰效果。本研究在对SO₂与MnO₂的反应机理进行分析和研究基础上，在国内外首次对锰矿浆处理低含量SO₂系统的动力学进行了研究，并率先将喷射鼓泡反应器引入锰浆脱硫过程，并对该过程的工艺参数、工艺组合以及催化作用等进行了较为深入的研究，得出：（1）该过程属气膜控制。这可由过程的反应速度随气相搅拌强度增大而增大，与气液相界面积成正比以及反应速度基本不随液相搅拌强度变化得到证实。过程的宏观动力学方程：其中 通过实验确定喷射鼓泡反应器（JBR）较佳结构参数。气体喷射系统：喷射口插入深度（h）100～240mm；喷射速度（V）6～9m/s；喷射口直径（d₀）3mm。矿浆搅拌系统：采用上旋式搅拌器；搅拌器的直径d与反应器直径D之比为d/D=0.35；搅拌器下端离反应器底部的距离y与搅拌器直径d之比为y/d=0.5；搅拌转速500-600r/min。同时JBR反应器将SO₂吸收和浸锰放在一个设备中进行（如图4—14），省去了矿浆外部循环系统，避免了泵的能耗和磨损，该反应器传质、反应速度快，处理能力大。（3）对烟气脱硫率（η）与锰浸出率（X_B）之间关系的实验数据进行线性回归，得到n和X_B的实用数学模型。单级JBR反应器连续运行时，η=0.945-0.472X_B²；两级串联JBR反应器连续运行时，η=0.982-0.23X_B²。（4）采用两级串联JBR反应器的连续运行可同时获得80％～85％的脱硫率和 四川大学博士学位论文锰浸出率。吸收液经过滤、除Fe、AI、Ca、Mg、Co、Ni、Ph等杂质，结晶后，可获得达到国家一级标准（GB 622E6）的MnSO。·Hp产品。u)实验中发现在JBR反应器中，搅拌强度可影响软锰矿浆脱硫反应过程。对用空气配制的低含量 SO。烟气，当搅拌转速 ＜ 500dIYlln时，SO。主要与 MnO。反应生成MnSO4；当搅拌转速 3 1000rlinin时，溶解氧增多，SO。主要在锰离子的催化作用下生成HpO尸因此，在高搅拌强度下，可用软锰矿催化氧化脱硫制得含量约为20％的稀酸。这也是本研究的又一新发现。更多还原

【Abstract】 Flue gas desulfurization with pyrolusite pulp, it not only can remove low concentration SO2 in flue gas, but also gain valuable by product MnSO4. In experiment applying Jet Bubbling Reactor (JBR) made by us as SO2-absorbing apparatus, using air(or N2)-SO2 mixtures as simulated flue gas, and mixing ore powder (<0.1mm) and water as ore pulp. Simulate flue gas was absorbed continually through JBR loading pyrolusite pulp, and desulfurization ratio and ratio of leaching Mn2+ were examined under various experimental conditions. On the basis of discussion and analysis for reaction mechanism and process of SO2 and MnO2, first studying on macro-kinetics of process of pyrolusite pulp absorbing SO2 at home and abroad. At the same time for the first time drawing JBR into desulfurization process with pyrolusite pulp. Furthermore, studying deeply on various technological parameters, combination of technological unite, as well as SO2 oxidized H2SO4 under catalytic function of Mn2+ at high agitation rate. Experimental results and study show that (1) The reaction rate of process is limited by diffusion of SO2 gas into aqueous phase. The conclusion is supported by reaction rate goes up with increase of stirring speed of gas phase(Fig. 3-6) , and is in linear relationship to gas-liquid phase area(Fig. 3-8). Finally the model of macro-kinetic is established to describe the reaction rate of the process:in which:(2) Optimum construction parameters of JBR are determined by experiment. Jet system of flue gas: the depth (h) of 100~240mm for jet hole plunging in solution; Jet velocity (V) of 6~9m/s; Diameter (do) of 3mm for jet hole. Agitation system of pyrolusite pulp: a ratio of the agitation diameter (d) to reactor diameter (D) : d/D =0.35; a ratio of distance (y) of agitation from the bottom of reactor to agitationdiameter (d): y/d = 0.5; agitation rate of 500~600r/min. Also, JBR has the feature that absorbing SO2 and leaching Mn2+ were carried out in the same apparatus , so there is no out-circling equipment system to avoid ore pulp pump. (3) The model between n and XB relationship are determined by fitting the experimental data to a linear regression equation. For single JBR running continually : * = 0.945 - 0.472XB ; For two connection of JBRs running continually : = 0.982-0.23XB? (4) Both desulfurization rate and rate of leachingMnz+ may reach 80%~85% using two-connection JBRs,. Furthermore, leaching solution were filtered, removed impurities, such as Fe, Al, Ca, Mg, Co, Ni and Pb, and crystallized lastly. MnSO4 H2O could be gained which can meet National Standard (GB1622-86). (5) Stirring speed can influence reaction of desulfurization with pyrolusite pulp. When stirring speed < 500r/min, SO2 mainly react MnO2 to produce MnSO4, and when stirring speed >1000r/min, because of increase of solving oxgen in solution, SO2 was oxidized to H2SO4 under the Mn2+ catalysis. Thus, it is a another new finding that SO2 in flue gas could be oxidized to rare H2SO4(10%~20%) with pyrolusite pulp under high agitation rate.更多还原