Determination of total sulfur in coal by ultraviolet fluorescence method based on the large capacity combustion framework

In this paper, a systematic method for determination of total sulfur in coal by ultraviolet fluorescence is established based on a self-developed large capacity combustion framework (LCCF). The simple oxidation-combustion mode is upgraded to the pyrolysis-oxidation-combustion mode with the help of LCCF. Thus, components to be analyzed is pyrolyzed slowly and the whole decomposition process of sample is prolonged, which could improve the consistence of test results. The sampling size to be sent into LCCF is significantly increased, and the representativeness of samples is secured, which promotes the improvement of accuracy of testing results. Detection limits are augmented without additional hardware or software improvements by this way. The test systems equipped with conventional combustion tube (CCT) and self-developed LCCF are established differently to test standard coal samples (SCS) and ordinary coal samples (OCS) with different total sulfur range. Accuracy and precision of the two test systems are tested and the optimal injection quantity of the system with LCCF is determined. The results show that LCCF could support the injection quantity of 1000mg and ensure stable and complete combustion of sample, which is far more than that of CCT. The accuracy and precision of the test results are better than the requirements of the existing conventional analysis standards, which shows the excellent structure of LCCF and good performance. The new analysis system can further expand the application of ultraviolet fluorescence method in field of coal and others.