1.Introduction

Manganese is one of the most important deoxidizing agent and alloying agent in steelmaking process, and silicon is the most important alloying element next to manganese in pig iron and carbon steel. A large amount of manganese and silicon are added to the liquid steel in the form of silicon-manganese alloy to optimize the structure of steel and improve the mechanical properties of steel products. Therefore, it is necessary to accurately determine the content of elements in silicomanganese alloy, which is not only related to the cost of steelmaking production, but also related to whether the quality of steel products can meet the needs of customers. The content of manganese silicon phosphorus and other elements in silicomanganese alloy is usually determined by chemical wet method or ICP analysis, time-consuming and complicated operation requires a large number of chemical reagents. The production of acid gas and waste liquid in the detection process pollutes the environment, which is difficult to meet the requirements of rapid batch detection, and does not meet the green environmental protection requirements of steel enterprises. X - ray fluorescence spectrometry (XRF) has wide range, high accuracy and high detection speed, It can quantitatively analyze various elements in solid, powder and liquid samples and has become an important chemical composition detection technology widely used in iron and steel metallurgical raw materials and products. XRF analysis adopts conventional low-pressure tablet for sample preparation, which is simple and fast, but cannot eliminate sample size and mineral effect. Moreover, powder is easy to drop during detection, affecting detection results and damaging the X-ray tube of the instrument. The borate melting sample preparation technology can eliminate the mineral and matrix effects of the samples to the greatest extent, but the platinum crucible is easy to be eroded by the alloy in the high temperature melting state, which leads to the high cost. The UHPS ultra-high pressure system of Ruishenbao is used in a steel plant to directly press the sample, the main element and impurity elements are rapidly detected simultaneously , the test steps are simplified, the labor intensity is reduced, the pollution is avoided, and satisfactory results are obtained.The sample preparation method is as follows:

2. Sample making equipment and tools

2.1. The equipment

Ultra-high Pressure System-UHPS

2.2. Sample cup

Polyethylene sample cup (hereinafter referred to as PE cup)

2.3. Ginding equipment

Vibratory Disc Mill PrepM-01

3. Sample preparation

In a chrome steel grinding box of 100ml volume, place 3/1 of ferrosilicon. Using prepm-01 vibration disc mill, set at 1200 RPM,  grind the sample particles for 3min to 75 μm(which can pass through 200 mesh sieve), and pour out the sample for use.

Spread the sample in the PE cup,( The required sample quantity is just enough to fill the entire mold). Gently place the mold filled with samples into the groove of the sample table of the UHPS press prototype to avoid the sample splashing (please make sure the sample table is clean before placing the sample). After placing the sample, cover the tungsten carbide gasket and press the gasket into the sample slot with your finger to ensure that the upper surface of the tungsten carbide gasket cannot exceed the upper surface of the mold. At the same time,  close the protection door and start the program. Set the parameters of the UHPS press machine as pressure 2000KN, pressure holding time 20S, exhaust time 6S. Click start to automatically start pressure holding. After the time of pressure holding, automatic pressure relief, automatic sample drawing, take off the mold cover, and take off the sample.

4. Conclusion

A number of standard samples and samples were selected and pressed into samples, and then XRF was used for analysis and determination, After four tests, the same sample was compared with the conventional low-pressure tablet sample (40T). Some results are shown in the table below. The results in the table show that both different samples and the same sample have good precision, and the measured value has a good consistency with the standard value, and its analysis accuracy is within the tolerance range stipulated by the national standard, which can fully meet the needs of daily production inspection. The sample doesn‘t need to be pretreated, and no additional chemical reagent is needed. It only takes a few minutes for a sample to make a sample tablet, which is economical, simple and environmentally friendly.