微波辐射干燥单水氢氧化锂的研究

本文研究了利用微波辐射干燥单水氢氧化铝的工艺，并分析了微波功率、辐射时间、物料重量和物料厚度对物料脱水率的影响。     

石膏型干燥工艺研究

通过微波炉和鼓风烘干箱烘干，研究石膏型的干燥规律。干燥工艺中，采用同一配比不同填料（铝矾土、石英砂）制成的实验试样，研究微波功率和微波干燥时间对干燥效果的影响，得出石膏型的微波干燥规律。结果表明微波炉作为干燥设备更具有优越性。     

微波干燥高钛渣的响应曲面法优化

采用基于Box-Behnken设计的响应曲面法,考察微波干燥温度、时间和料重的交互作用对高钛渣含水率和试样失水速率的影响,通过实验设计、方差分析、模型拟合、参数优化及结果验证等,得到最优化工艺条件为:干燥温度76℃,时间10s,料重45g,在此条件下,预测试样含水率0.25%,实际实验值0.28%,预测值和实验值吻合性较好。     

铸造用膨润土的夯压改性试验研究

采用夯压法对广西宁明钙基膨润土进行钠化改性,研究了钠化剂种类、钠化剂用量、夯压时间、物料含水率及干燥温度等因素对钠化效果的影响.通过理化性能检测分析,Na2CO3为广西宁明钙基膨润土夯压改性最佳的钠化试剂.当Na2CO3用量为膨润土质量的5％,物料含水率18％,夯压时间20min,干燥温度120℃以下制备的钠基膨润土钠化效果最好.     

微波活化焙烧辉钼矿生产低硫氧化钼

对比研究了微波功率、作用时间及物料质量对辉钼矿预活化焙烧后的脱硫效果的影响,并采用气-固多相反应的未反应收缩核模型研究了辉钼矿氧化焙烧的动力学。结果表明,辉钼矿的吸波性能良好,在微波功率0.64 k W、物料质量30 g、微波作用6 min的条件下,微波可比常规处理方式显著降低硫含量0.256%;辉钼矿氧化焙烧是强放热反应,温度越高,辉钼矿氧化速率越快;540~630℃时转化率明显增高,界面化学反应是控制性环节。微波对于辉钼矿在常规氧化焙烧之前的活化作用已得到试验验证,若应用于工业生产,可采用短时间活化焙烧预处理来辅助常规的氧化焙烧。     

微波活化焙烧辉钼矿生产低硫氧化钼（英文）

对比研究了微波功率、作用时间及物料质量对辉钼矿预活化焙烧后的脱硫效果的影响,并采用气-固多相反应的未反应收缩核模型研究了辉钼矿氧化焙烧的动力学。结果表明,辉钼矿的吸波性能良好,在微波功率0.64 k W、物料质量30 g、微波作用6 min的条件下,微波可比常规处理方式显著降低硫含量0.256%;辉钼矿氧化焙烧是强放热反应,温度越高,辉钼矿氧化速率越快;540~630℃时转化率明显增高,界面化学反应是控制性环节。微波对于辉钼矿在常规氧化焙烧之前的活化作用已得到试验验证,若应用于工业生产,可采用短时间活化焙烧预处理来辅助常规的氧化焙烧。     

烟化炉产氧化锌烟尘的介电特性及温升特性

为了研究微波焙烧脱除氧化锌烟尘中氟氯的可行性以及氧化锌烟尘的吸波特性,采用谐振腔微扰法对不同物料密度氧化锌烟尘的介电特性（ε′,ε″和tanδ）进行测定。氧化锌烟尘的介电常数、介电损耗和损耗角正切值与氧化锌烟尘的表观密度成正比。在微波场下研究物料质量和微波功率对氧化锌烟尘升温特性的影响。结果表明,氧化锌烟尘对微波具有较强的吸波能力,其表观升温速率与微波焙烧功率成正比,与质量成反比,在8 min内温度可到达800℃。     

喷雾干燥结合微波煅烧法制备微米级球形钼粉的研究

本文以仲钼酸铵(优级纯)为原料,通过结合气流式雾化干燥法和微波煅烧氢还原法制备出球形、微米级、比表面积大、分散性好的钼粉。重点研究雾化造粒过程和微波煅烧氢还原阶段的升温速率对最终Mo粉的形貌、粒度以及比表面积的影响及规律。研究结果表明,控制一定的参数可以制备出球形、微米级、分散性好的钼酸铵前驱体粉末;最终Mo粉的微观形貌受升温速率的影响,升温速率越低制备的Mo粉破碎越严重,且有少量团聚现象,升温速率越高制备的Mo粉球形度越高,分散性越好;升温速率也直接影响平均粒度和比表面积,升温速率越低,平均粒度越小,而比表面积越大,升温速率越高,平均粒度相应增大,比表面减小。     

高功率微波等离子体对单晶金刚石同质外延生长的影响

目的 为了优化单晶金刚石大批量生长的等离子体环境,研究高功率微波等离子体环境对单晶金刚石外延生长层的影响。方法 利用实验室自主研发的915 MHz–MPCVD装置,在20～35 kW高功率微波馈入的条件下,具体研究了高功率等离子体环境中甲烷浓度、微波功率及基片温度对单晶金刚石外延生长层的影响。利用光学显微镜、激光拉曼光谱及光致发光光谱对所生长的单晶金刚石进行形貌质量表征,利用等离子体发射光谱对高功率微波等离子体环境进行诊断。结果 在馈入25 kW的微波功率时,将甲烷的体积分数从6%下降至3%,可以使单晶金刚石更易于出现层状生长结构;保持甲烷体积分数为3%,将微波功率从25 kW提高到35 kW,可以进一步优化单晶金刚石生长的层状结构,提高单晶金刚石的生长质量和生长速率;保持微波功率为35 kW,当甲烷体积分数为3%时,将基片温度从800℃提高到1 210℃可以明显提高单晶金刚石的生长速率,但会易于引入非金刚石相;保持甲烷体积分数为3%,将微波功率提高到35 kW,可以在等离子体中激发更多有利于金刚石快速生长的含碳活性基团;当微波功率为35 kW、甲烷体积分数为3%、基片温度为950℃时...     

基于单片机的微波连续干燥机控制系统设计

针对目前物料微波干燥过程中温度和湿度存在耦合关系导致执行机构工作稳定性差、干燥能耗大、效率低、烘干不均匀等问题,设计基于单片机的智能控制系统,分析并选择了温度、湿度、水分传感器等主要器件。该系统采用温湿度传感器来检测干燥箱内的信息,能够完成干燥箱内参数值的设定,实现温湿度超限报警并自动调节相应装置。试验结果表明:该智能控制系统控制性能好,自动化纯度高,可以有效保证物料干燥品质。     

微波场下渗硼介质的温度特性研究

利用渗硼介质吸收微波的特性可实现钢铁表面渗硼层的制备，渗硼介质与微波作用产生的温度特性是影响渗硼层形成最主要的因素。用热电偶精确测定微波场下渗硼介质的温度，采用MATLAB对实验数据进行了曲面插值拟合和分析，结果表明：微波功率（900-3600W）和渗硼剂质量（40-160g）对升温速率和稳定温度有较大影响，且当微波功率为1800W和2700W时，加热温升曲线符合Boltzmann方程；加热过程可以分为开始升温阶段、升温阶段和温度稳定三个阶段。     

微波快速测量球团铁精矿混合原料水分新方法

对目前几种测量水分的方法进行了评述，研究了用微波快速测量球团混合铁精矿原料水分的新方法，并分析和讨论了不同混合铁精矿原料水分含量对检测结果的影响。实验结果为：当球团混合铁精矿原料的含水量为6．97％-9．81％时，检测误差小于0．17％。该研究有望为球团混合铁精矿原料水分快速测量提供一种新力法．     

微波辅助磨碎钛铁矿

研究微波加热对攀枝花钛铁矿磨矿性能的影响。微波辐射时间、微波功率密度和样品质量是磨矿过程的重要参数。将40g样品在微波功率1kW下辐射30s,然后进行水淬处理。SEM分析结果表明：经过微波辐射处理的钛铁矿在有用矿物和脉石间产生了裂纹,能够有效地促进矿物与脉石的解离。在随后的磁选实验中,经过微波辐射处理的钛铁矿的回收率从44%提高到72%。     

The influence of microwave heating on the mechanical properties of wood

The drying of wood can be a time-consuming process. The timber industry has been using several methods to reduce the drying time of timber for many years; these include drying the wood at elevated temperatures in conventional ovens or kilns, drying in radio frequency or microwave ovens, or a combination of the two. Little attention has been given to quantifying the effect of drying method on the mechanical properties of the wood, especially where this involves microwave energy with its interior to exterior heating characteristics. In this study, Carribean pine timber was dried to pre-determined moisture contents using several drying methods. The wood specimens were then subjected to tensile loading in order to determine the mechanical properties of the dried timber samples. The wood was dried in air at ambient temperature, in a conventional oven at two elevated temperatures and in a microwave oven at two different power settings. The results of the mechanical tests were then compared for the various drying methods. These revealed that microwave drying reduced the strength of the dried timber by as much as 60%.     

铸造型砂智能水分测量系统研究与设计

铸造型砂水分含量直接影响型砂性能,进而影响铸件质量.智能微波水分测量系统集成了微波水分测量与智能测量的技术优势,能够实现快速、高精度、高可靠性、高稳定性的在线式型砂水分测量.基于微波能量衰减法测量水分,应用非线性智能算法实现温度补偿,由水分传感器与温度传感器实时测得的两路信号变送至单片机,单片机完成数据处理并输出控制信号以控制实时加水量.在对所构建的智能微波水分测量系统的特点进行描述的基础上,着重分析了测量系统总体构成、测量装置原理及其组件功能、测量系统的硬软件实现等方面.     

水玻璃砂微波硬化强度的试验研究

采用微波加热技术来加热硬化水玻璃砂,通过改变水玻璃的加入量、调整微波加热时间和加热功率等工艺因素,分析微波加热对砂型试样抗拉强度的影响规律。试验结果表明,采用539 W功率加热,水玻璃的加入量为3.0%时,其抗拉强度在25 min时达到的最大值为1.11 MPa,可满足型砂的使用要求。     

微波辐射Mg(OH)2制备轻质活性MgO新工艺

探讨了微波辐射Mg(OH)2制备轻质活性MgO的可行性，研究了微波功率、微波辐射时间、物料重量对Mg(OH)2分解率的影响，得到了微波辐射Mg(OH)2制备轻质活性MgO的最佳工艺：微波功率800W，微波辐射时间8分钟．物料重量4克，其煅烧时间只有传统方法的1／10，Mg(OH)2分解率为99．62％，氧化镁含量95．09％，碘吸附值为78．68mg／g，产品指标达到了沪Q/HGll-238-82一极标准。     

X-ray images of defect formation in porcelain ceramics during drying

The drying phase during the manufacture of ceramic pieces is often the point of failure owing to the formation of cracks. In this study, non-destructive microfocus X-ray imaging has been employed to study the onset of cracking in porcelain and correlate it with the moisture content. Samples of moist porcelain paste were extruded through dies of 30 and 50 mm diameter. Sections of the extrudate were placed into an X-ray transparent oven and imaged while drying at constant temperature and low humidity. The time to the onset of cracking was found to be a function of temperature. The mode of failure was consistent across the temperature range 40–120 °C.The higher the drying temperature, the shorter the time to failure and the higher the moisture loss at failure. For a particular paste consistency and sample geometry there was found to be a critical moisture content below which cracking began to occur. This moisture threshold was observed to be weakly temperature dependent; it appears to be more sensitive to sample geometry and paste consistency. A safe drying curve has been constructed which provides a boundary for the process parameters which prevent cracking. The implication is that during the drying of a ceramic piece, different sections may have different safe parameter boundaries and the process must be designed to keep all sections within the safe region.     

Properties of sodium silicate bonded sand hardened by microwave heating

The sodium silicate bonded sand hardened by microwave heating has many advantages,such as low sodium silicate adding quantity,fast hardening speed,high room temperature strength,good collapsibility and certain surface stability. However,it has big moisture absorbability in the air,which would lead to the compression strength and the surface stability of the sand molds being sharply reduced. In this study,the moisture absorbability of the sodium silicate bonded sand hardened by microwave heating in different humidity conditions and the effect factors were investigated. Meanwhile,the reasons for the big moisture absorbability of the sand were analyzed.Some measures to overcome the problems of high moisture absorbability,bad surface stability and sharply reducing strength in the air were discussed. The results of this study establish the foundation of green and clean foundry technology based on the microwave heating hardening sodium silicate sand process.