Abstract:Through the application research on the reaction principle for the wet ablating chromite by sulfuric acid at high temperature(～330 ℃), the sample dissolution method for determination of chromium in chromite was improved. The sample was heated (in a 2000 W electric furnace) with sulfuric acid until thick sulfur trioxide smoke appeared and then soared for >6 min. Then the sample was heated again with phosphoric acid until thick smoke appeared and soared to the level of about 2/3 height of the beaker wall. After the sample was cooled properly, diluted and oxidized, the chromium contents were determined by normal method. By comparing the analytical results of the production samples with the standards and the verification experiments (RSD=0.15%～0.18%, n=10), it concluded that the improved sample dissolution method can give satisfactory results.