废纺织原料中锶-90的检测技术研究

Research on the Detection Technology of Strontium-90 in Waste Textile Raw Material

常见的废纺织原料为棉、棉短绒、废棉、石棉、动物毛纤维、麻纤维等。本文选择棉、麻、丝、毛、尼龙5种代表性废纺织原料为样本,样品灰化后消解,利用碳酸钙共沉淀法富集其中锶(Sr)。通过使用DtBuH18C6冠状醚锶树脂,在适宜酸碱条件下,分离钇(Y)等金属离子,得到目标元素锶。用硝酸溶液、硝酸-草酸溶液洗涤树脂,除去钙(Ca)、钡(Ba)和其他碱土金属离子、稀土离子的干扰。再用稀硝酸溶液解吸树脂柱上的锶,利用低本底αβ测量仪测量放射性物质锶-90含量。在实验过程中,示踪剂采用稳定的锶载体加入,通过重量法得到方法的回收率,以此校正实验数据,从而保证方法的精密度和准确性。通过该方法研究,当使用纺织原料为样品时,该方法的回收率在83%左右,探测下限均值为0.93 Bq/kg。该方法可以快速测定废纺织原料中锶-90的含量,对口岸监管固体废物属性鉴定具有重要意义。

Common waste textile materials include cotton,cotton lint,waste cotton,asbestos,animal hair fibers,and hemp fibers etc.This article selects five representative waste textile raw materials:cotton,linen,silk,wool,and nylon as samples.The samples were digested after ashing,and the strontium was enriched by calcium carbonate co-precipitation method.The target element strontium was obtained by separating metal ions such as yttrium(Y)with DtBuH18C6 coronal-ether strontium resin under suitable acid-base conditions.Wash the resin with nitric acid solution and nitric oxalic acid solution to remove the interference from calcium(Ca),barium(Ba)and other alkaline earth metal ions and rare earth ions.At last,dilute nitric acid solution was used for desorption of strontium and low backgroundαβmeasuring instrument was used to measure the content of Strontium-90(^(90)Sr).During the experimental study,the tracer was added with stable strontium carrier,and the recovery rate of the method was obtained by gravimetric method,so as to correct the experimental data and ensure the precision and aaccuracy of the method.Through the method study,when the textile raw material is used as the sample,the recovery rate of the method was about 83%,and the average detection limit of the method was 0.93 Bq/kg.This method can quickly determine the content of ^(90)Sr in waste textile materials,which is of great significance for the identification of solid waste properties in port supervision.