Intensification of solid–liquid separation by thermal sedimentation in pressure oxidative leaching process of chromite

•Thermal sedimentation was firstly adopted in the separation of chromite leaching.•Thermal sedimentation method can shorten the separation time by up to 71.9%.•Alkali solution after thermal sedimentation separation can be directly reused.•When sedimentation temperature was 150 °C, sedimentation efficiency was higher.