秸秆添加量对自蔓延高温合成纳米氧化锡的影响

针对目前我国秸秆资源利用率较低、浪费严重的现状，首次将农作物秸秆粉末引入纳米氧化锡自蔓延高温合成体系（SHS）构建。以固定比例Mg、Al、Sn、CuO、Fe3O4、SnO2和CaF2组成总量一定的基础合成体系为研究对象，利用激光粒度仪和原子吸收分光光度计对所得纳米氧化锡进行表征，分析秸秆添加量在0~40%（重量比）范围内纳米氧化锡有效转化率、粒径和组成元素的变化规律，借助常规函数拟合与数学建模，演绎秸秆添加条件下纳米氧化锡的形成过程，获得秸秆添加量对纳米氧化锡的影响机制，证明利用秸秆粉末进行纳米氧化锡的自蔓延高温合成具备可行性。结果表明，秸秆添加量的有效范围在0~28.57%之间，且于28.57%处获得最佳效果，可使纳米氧化锡有效转化率提升19.87%，但超出此范围，纳米氧化锡中将出现含Cu杂质。在有效范围内，秸秆添加质量比和纳米氧化锡有效转化率及含锡量的关系，均能通过二次多项式表达，拟合决定系数分别高达0.997 95和0.999 97，标准化残差低至0.000 12和0.000 00，随秸秆添加量增大，纳米氧化锡有效转化率和含锡量均增大；但秸秆添加质量比和纳米氧化锡平均粒径之间不存在简单函数关系，尚无法仅通过调整秸秆添加量来调控纳米氧化锡的粒径大小。

Influence of Addition Amount of Straw on Nano-tin Oxide Product Prepared by SHS Method

Owing to the status of low utilization rate and severe waste of crop straw resources in our country, this paper introduced crop straw powder for the first time to nano-tin oxide prepared by self-propagating high-temperature synthesis system (SHS). Taking fixed proportion of Mg, Al, Sn, CuO, Fe3O4, SnO2 and CaF2 to compose a basic synthesis system with certain quantum as research objective, this paper characterized nano-tin oxide products by a laser particle analyzer and atomic absorption spectrophotometer; analyzed the nano-tin oxide effective percent conversion, grain size and changing law of component when the straw addition quantity varied from 0~40%（weight ratio）by common function fitting and mathematical modeling; deduced the formation process of nano-tin oxide products under condition of adding crop straw; and obtained mechanism affecting nano-tin oxide by straw addition quantity. Thus, the feasibility of using crop straw powder for SHS of nano-tin oxide was proved. Results showed that appropriate crop straw addition quantity could be varified from 0~28.57%, and 28.57% could obtain the best effect, increasing the effective conversion rate by 19.87%. But if over this range, nano-tin oxide would contain Cu impurity. Within effective range, the relationship of straw addition quantity with effective nano-tin oxide conversion rate and Sn content of nano-tin oxide products could be described by a quadratic polynomial with determination coefficients of 0.997 95 and 0.999 97. The standard residual were less than 0.000 12 and 0.000 00, and the effective conversion rate of nano-tin oxide and Sn content would increase along with the increasing of straw addition quantity. But, there was no simple function relationship between straw addition mass ratio and mean grain size of nano-tin oxide, meaning it was impossible to control the partical size of nano-tin oxide only by adjusting straw addition quantity.