高硫矿物化学解离与旋转离散电极协同强化电解脱硫机制

Based on lower desulfurization ratio resulted from poor contact of sulfur and oxidant, synergistic desulurization method for ore dissociation and rotary dispersion electctrode together was suggested in this work. Sulfur dissociation was strengthen through control of electrolyte composition, making sulfur passed from matrix to surface easily. Considering smaller surface area of panel electrode and lower lifetime of oxidant from water electrolysis, the rotary dispension electrode was carried out to strengthen mass transfer of oxidant in electrolyte and interface between electrode and ore particle. Mass transfer of sulfur and oxidant was improved through the synergy of ore dissociation and rotary dispersion electctrode, resulting in the incrase in contact between sulfur and oxidant, boosting electrolysis desulfurization ratio. Dissociation of sulfur in matrix was improved by controlling of composition and structure of organic and inorganic solvent. Mechanism of mass transfer for oxidant in electrolyte and interface between electrode and ore particle strenghened by rotary dispension electrode was examined through control of ball material, paricle size, quantity and ratary rate. Synergistic mechanism of sulfur removal strengthen by sulfur dissociation and rotary dispersion electrode was studied through electrolysis desulurization kinetics and process of synergistic mass transfer between sulfur and oxidant, to supply theoretical basis for electrolysis desulfurization technology.

由于矿物基体硫与水电解产生氧化基团接触机会少，导致电解氧化脱硫效率低，项目提出了矿物活化解离与旋转离散电极协同强化传质的思路。通过调控电解液配方，强化电解液对矿物基体硫的活化解离作用，使硫由矿物颗粒基体向表面传递。通过旋转离散电极强化氧化基团在电解液、电极与矿物颗粒界面的传递。通过矿物解离活化与旋转离散电极的协同调控，强化硫在颗粒内部传质与氧化基团传质的协同，增加硫与氧化基团的接触机会，提高矿浆电解脱硫率。 通过调控电解液中有机、无机溶剂组成与结构，探索矿物基体硫活化解离机制。通过调控小球材料、数量、粒度、旋转速率强化氧化基团传递能力，解析旋转离散电极强化氧化基团在电解液、电极与矿物颗粒界面传质机制。通过研究矿物活化解离与旋转离散电极协同脱硫动力学及硫和氧化基团协同传质动力学，揭示矿物解离活化与旋转离散电极协同强化电解脱硫机制，为电解脱硫技术提供科学依据。

针对高硫矿物硫赋存状态及电解水活性氧的形成特点，项目采用调控电解组成强化高硫矿物的化学解离，解析了有机硫和无机硫化学解离机制；通过采用旋转离散电极、超声、加压等方式，强化了电解水产生活性氧的种类与数量，增加了活性氧与硫元素的接触几率，提高电解脱离效率。研究表明电解液中加入离子液体或NaOH等可将高硫矿物中的硫元素进行解离，从而使得从矿物颗粒本体迁移或断裂，形成矿物表面硫。研究表明离散电极不仅强化了活性氧形成和传递，而且也使得矿物颗粒细化，暴露出更多的硫原子，便于电解氧化脱除；同样的超声、加压过程也细化了高硫矿物颗粒，如煤颗粒、铝土矿颗粒；更重的是强化阴阳两极的活性氧的种类和数量，如羟基自由基、超氧负离子。羟基自由基是电解过程最重要的活性氧，对脱硫的贡献最大。.通过ESR和电化学表征，解析了外场强化活性氧形成机制，证明了旋转离散电极、超声、加压等外场不仅强化了活性氧前驱体在边界层的传递，而且强化了在电极表面的电子得失。研究表明超声和加压外场增加了羟基自由基存在电位范围，拓宽了存在介稳区间。超声不仅强化了羟基自由基形成，也强化羟基自由基在电极表面的脱附，强化了有效活性氧的数量。结合量子化学密度泛函理论计算，解析了羟基自由基氧化黄铁矿机理，表明羟基自由基对S、Fe原子的吸附尤为关键，羟基自由基通过对Fe原子的完全氧化，增加了Fe-S的断裂机会，导致溶液中硫代硫酸根离子浓度增加，强化了电解脱硫。而碱性体系下，氢氧根是抑制Fe3+存在的关键，不仅生成Fe(OH)3强化活性氧的形成，同时抑制了Fe3+的氧化作用。