There are two main methods for analyzing powder samples by XRF spectroscopy: powder pressing method and melting method. For microanalysis with a very small amount of sample, there is also a thin sample method, which will not be introduced here.
The melting method is a widely used sample preparation method, which can better eliminate the influence of particle size effect and mineral effect. However, the fusion method also has disadvantages: the measurement intensity of light elements is reduced because the sample is diluted and absorbed by the flux; the sample preparation is complicated and takes a lot of time; the cost is also high.
The advantages of the powder compression method are simple, fast and economical. It is widely used when the analysis workload is large and the analysis accuracy is not too high. It is also commonly used in the analysis of trace elements. Judging from the recent two collections of papers published by the CHINA Science XRF Spectrometer Association and the CHINA Phillips X-ray Analytical Instrument Association, articles that use powder compression to prepare samples account for a large proportion. In practical applications such as the analysis of cement, rock, and chemical exploration samples, powder pressing is still a widely used XRF sample preparation method.
There are three main steps in the powder compression tablet preparation method: drying and roasting; mixing and grinding; tabletting. There are methods such as powder direct compression, powder dilution compression, and binder substrate and bordering.
