X射线衍射标准曲线法测定氧化锌富集物中游离态氧化锌

氧化锌富集物的进口能弥补我国锌矿资源的不足,但要求其游离态ZnO不小于50%。目前常采用YS/T 1171.10—2017(Na₂EDTA滴定法)测定氧化锌富集物中ZnO含量,该方法测定过程冗长繁琐,测定1个样品需要2 d时间,已不能满足大批量氧化锌富集物进口快速通关的需要。故实验建立了采用X射线衍射(XRD)标准曲线法测定氧化锌富集物中游离态ZnO的方法。采用YS/T 1171.10—2017对进口氧化锌富集物样品进行定值,然后选取15个ZnO含量具有梯度的样品作为校准样品,选用ZnO最强衍射线(101)作为测量谱线,建立起积分强度对ZnO含量的标准曲线,曲线呈现较好的线性。采用标准曲线法、全谱图拟合法、化学方法分别测定了3个进口氧化锌富集物中ZnO含量,标准曲线法测定值与化学方法测定值一致,全谱图拟合法测定值与化学方法测定值偏差较大。实验方法测定1个样品仅需26 min,能够满足大批量氧化锌富集物进口快速通关的检测需求。

Determination of free zinc oxide in zinc oxide enrichment by X-ray diffraction standard curve method

The import of zinc oxide (ZnO) enrichment can make up for the shortage of zinc mineral resources in China. The content of free ZnO should be higher than 50%. At present, the content of ZnO in ZnO enrichment is usually determined by YS/T 1171.10-2017 (Na₂EDTA titration). However, this method is tedious and time-consuming. Two days are required to determine one sample, which cannot meet the requirements of faster customs clearance during the import of large quantities of ZnO enrichment.A determination method of free ZnO in ZnO enrichment by X-ray diffraction (XRD) standard curve was established. The constant value analysis of imported ZnO enrichment sample was conducted by YS/T 1171.10-2017. Then 15 samples with ZnO content gradient were selected as the calibration sample to prepare the standard curve between integral intensity and ZnO content using the strong diffraction line (101) as the measuring line. The standard curve showed good linearity. The content of ZnO in three imported ZnO enrichment samples was determined using the proposed standard curve method, full spectrum fitting method and chemical method, respectively. The found result of standard curve method was consistent with that of chemical method. The measured value of full spectrum fitting method had great difference with that of chemical method. Only 26 min was required to determine one sample for the proposed standard curve method, which could meet the detection requirements of faster customs clearance during the import of large quantities of ZnO enrichment.