Ceramic electrolytes and secondary recovery

离子导电陶瓷的两个重要应用是高温原位传感器和固体氧化物燃料电池。不幸的是，在炼钢过程中用于测定溶解氧的稳定氧化锆在低氧浓度下由于部分分解而变得不准确。目前正在研究两种更稳定的新型固体电解质Y2O3-CaO和Dy2O3-CaO，以开发更精确的氧传感器。针对CO2、SO2、NOx等污染气体和温室气体的气体传感器存在的主要问题是响应缓慢、灵敏度差和浓度范围有限。为了克服这些困难，微电子技术的小型化和一种新的气相沉积方法——极化电化学气相沉积，正被应用于含有氧盐或B”-Al2O3电解质的传感器。气相沉积技术在提高固体氧化物燃料电池复合阳极的电化学活性和稳定性方面得到了推广。氧化钇稳定的氧化锆沉积在先前丝网印刷的镍上，以提供独特的复合微观结构-两相是连续的，以尽量减少电阻损失。这项工作包括在镍上沉积铈，以改善催化行为，并在天然气上测试陶瓷涂层是否限制了麻烦的碳沉积。对油砂粉煤灰在焦炭燃烧形成过程中的矿物学变化进行了详细的研究，在较小程度上，在添加添加剂的焙烧过程中，部分地导致了从这种废物中回收钒和几种副产物的过程。此外，还提出了一种方法，利用另一种废物油砂焦，将油砂尾矿中的锆石转化为更有价值的氧化锆。用添加剂焙烧实现的矿物转化正在扩大到处理其他复杂和有潜在危险的废物产品，以便回收有价值的金属或使有毒元素对环境无害，例如铁酸锌残渣、电弧炉炼钢粉尘、铜镍砷硫化物废物。

Two important applications for ionically conducting ceramics are high temperature in situ sensors and solid oxide fuel cells.  Unfortunately, stabilized zirconia used for determining dissolved oxygen during steelmaking operations becomes inaccurate at low oxygen concentrations due to partial decomposition.  Two new solid electrolytes that are more stable, Y2O3-CaO and Dy2O3-CaO, are being studied in an effort to develop a more accurate oxygen sensor.  Major problems associated with gas sensors for polluting and greenhouse gases, e.g., CO2, SO2, NOx, are sluggish response, poor sensitivity and limited concentration range.  To help overcome these difficulties, miniaturization using microelectronic techniques and a new vapour deposition method, polarized electrochemical vapour deposition, are being applied to sensors involving oxysalt or B"-Al2O3 electrolytes.  The vapour deposition technique has been extended to improve the electrochemical activity and stability of the composite anode in the solid oxide fuel cell.  Yttria stabilized zirconia is deposited on previously screen printed nickel to provide a unique composite microstructure - both phases are continuous to minimize resistance losses.  Included in this work are ceria deposition on nickel to improve catalytic behaviour and testing with natural gas to see if the ceramic coating restricts troublesome carbon deposition.   A detailed investigation of oil sands fly ash on mineralogical changes occuring during its formation from coke combustion and, to a lesser extent, during roasting with additives has, in part, led to a process for the recovery of vanadium and several byproducts from this waste product.  Also, a process has been proposed to convert zircon from the oil sands tailings to much more valuable zirconia using another waste product, oil sands coke.  Mineral transformations, achieved by roasting with additives, are being extended to treat other complex and potentially hazardous waste products either to recover valuable metals or make toxic elements environmentally benign, e.g., zinc ferrite residue, electric arc furnace steelmaking dust, copper-nickel-arsenic sulphide waste.