水泥生料品质在线激光检测稳定性的技术研究  

Study on Stability Technology of Laser Based on Line Cement Raw Material Quality Monitoring

作　　者：弓瑶 张雷[1,2] 李郁芳[1] 赵洋[1] 赵书霞[1] 董磊[1,2] 马维光[1,2] 尹王保[1,2] 张向杰 肖连团[1,2] 贾锁堂[1,2] 

机构地区：[1]山西大学激光光谱研究所量子光学与光量子器件国家重点实验室,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006 [3]太原紫晶科技有限公司,山西太原030006

出　　处：《山西大学学报（自然科学版）》2016年第2期251-257,共7页Journal of Shanxi University(Natural Science Edition)

基　　金：国家重点基础研究发展计划(973计划)(2012CB921603);国家自然科学基金(61475093;61127017;61178009;61108030;61378047;61275213;61205216);国家科技支持计划(2013BAC14B01)

摘　　要：实时掌握水泥生料成分变化对于及时调整水泥原料配比和提高水泥产品质量具有重要意义。文章建立了一套喷射气粉混合物式的激光诱导击穿光谱(LIBS)水泥生料品质在线检测实验装置,并进行了以下优化:首先,发展了脉冲激光平均功率反馈稳定技术,稳功后激光器输出平均功率长期保持在设定值附近;接着加入了带中孔的凹面镜和扩束镜用以增大收光立体角和减小激光发散角,等离子体光谱中Ca(Ⅱ)318nm谱线强度从7 000提升到9 000,相对标准偏差(RSD)由3.49%降至1.34%,Mg(Ⅱ)279.7nm谱线强度从3 000提升到4 000,RSD由5.75%降至3.22%;最后,引入了一束照向喷射气粉混合物的405nm连续激光,将其散射光作为光谱归一化的参考值,使归一化后的光谱RSD由35%降至23%,明显优于全谱归一化的RSD值28%。为了验证经过上述优化后LIBS装置的测量稳定性效果,利用400组样品用于定标,其余100组用于验证。实验结果显示,经过优化后测量平均相对误差(ARE)由1.01%降至0.43%,且没有出现大的随机偏差。Mastering the change of cement raw materials composition in real time has important significance to timely adjusting the proportion of raw materials and improving the quality of cement products.We developed an experimental laser-induced breakdown spectroscopy（LIBS）device for on-line cement raw materials quality monitoring in the way of ejecting gas-powder mixture,and enhanced the measurement stability through the following approaches.Firstly,to stabilize the pulsed laser output power by adding laser power feedback adjusting.With stabilization,the laser output power has maintained at the pre-set value for a long time.Secondly,a beam expander（BE）and a concave mirror（CM）with a middle hole were employed to increase the excitation efficiency as well as the fluorescence collection efficiency.As a result,the line intensities of Ca（Ⅱ）318.0nm and Mg（Ⅱ）279.7nm was increased of 30% while the RSD was decreased of nearly 50%.Finally,a 405 nm continuous laser beam that pointed to the gas-powder mixture was employed in our LIBS device.The scattered laser was used as a spectral normalization parameter to make the RSD of normalized spectra decrease from 35%to 23%,which was much better than that of full spectrum normalization 28%.In order to verify the measurement stability of the optimized LIBS device,400 samples were used for calibration and the 100 samples were for validation.The results show that,the average relative error（ARE）has decreased from 1.01%to 0.43%,without any accidental large fluctuations.

关 键 词：激光诱导击穿光谱(LIBS) 在线检测 气粉混合物 脉冲激光平均功率稳定 光路优化 散射光光谱归一化 

分 类 号：O437[机械工程—光学工程] TN249[理学—光学]