Objective: To optimize processing technology of pyrolusitum. Method: Taking the content of MnO2 as index

orthogonal test was designed to optimize processing technology of pyrolusitum with processing temperature

the amount of vinegar and processing time as factors.Effects of processing technology on the content of MnO2 and microscopic morphology of pyrolusitum before and after processed were investigated. Result: The best processing technology of pyrolusitum were identified as calcining for forty min under temperature of 700 ℃ with vinegar amount of 20%;Under these conditions

the mass fraction of MnO2 in crude and processed products were (6.13±0.50)% and (7.35±3.27)%

respectively;Compared with crude products

after vinegar quenched of pyrolusitum

its transparent crystals number increased which could be observed under an optical microscope

appearance of crytals showed a lump or kidney shaped. Conclusion: This optimized technology was stable and feasible

which could provide a reference for criterion of processing technology of pyrolusitum.