Objective To sample and analyze leaking areas of drum in simulating drying test in concentrate drum to understand main causes of drum leakage. Methods Leaking areas of the drying drum was sampled by cutting. The sample pieces were decomposed based on subsequent analysis and test. The chemical composition, metallographic structure and grain size of the material of drying drum were analyzed and tested. The morphology in the corrosion area was been observed by SEM. Furthermore, the corrosion product was analyzed by energy spectrum. Afterwards, the results of analysis were compared with interrelated standards. Results The chemical composition of the material of drying drum conformed to regulation values of 304 stainless steel in ASME A240. The content of nonmetallic satisfied requirements of general engineering steel. The level of grain size was 6.5, but there were austenite and ferrite in the material of drying drum. This disagreed with the metallographic phase of 304 stainless steel. Lots of pit points and "rock candy shaped" corrosion product were observed in the sample. Corrosion also existed in areas without pit. Clear grain could be observed. The type of corrosion was pitting corrosion of stainless steel. Moreover, the Cl and F were also found in the corrosion product. Conclusion The corrosion of the container is induced mainly by the austenitic and ferrite metallographic in the container material. In addition, the existence of Cl and F also play certain role in the corrosion case.