Study on influencing factors of total sulfur determination in coal by coulometric method

WANG Jian; YIN Zhiyuan; WU Bihai; XU Jun

doi:10.3969/j.issn.1007-7677.2025.01.014

Abstract：Accurate determination of total sulfur content in coal is of great significance for understanding coal proper-ties and guiding production applications,thus it is necessary to summarize the influencing factors of the Coulomet-ric method for measuring total sulfur in coal.Based on the principle of the Coulometric method for measuring total sul-fur content in coal,by analyzing the main factors that affect the accuracy of measurement results,three factors were selected:pumping flow rate,tungsten trioxide spreading effect,and sample weighing mass,which are greatly influ-enced by instrument conditions and personnel operation.Each factor was set at three levels,and an orthogonal exper-imental design was conducted using an L9(34)table.Before the experiment,comprehensive maintenance and curve calibration were performed on the equipment to ensure its stability and reliability.Certified coal standard samples with low,medium,and high sulfur contents within the calibration range were selected for testing,and vari-ance analysis techniques were used to statistically analyze the results.The results indicated that when the sample mass was within the range of(50±5)mg,the sample mass had no significant effect on the results at a significance level of 95%;however,as the total sulfur content in the coal sample increased,the pumping flow rate and tungsten trioxide spreading effect gradually had a significant impact on the results at a significance level of 95%.This provides empiri-cal guidance for the practical application of the Coulometric method in measuring total sulfur in coal and serves as a reference for the development and improvement of intelligent Coulometric sulfur analyzers.