This paper provides on-the-ground accounts of epistemic violence against Black immigrant children in mathematics classrooms. From a critical feminist perspective, we introduce Dotson's notion of silencing as an enactment of epistemic violence. According to Dotson, one way to enact epistemic violence is to damage a particular group's ability to speak and be heard. A successful act of communication depends on the audience's willingness and ability to "hear" the speaker. Therefore, denying this reciprocity in communication is a form of epistemic violence. Using this conceptualization, we conducted a secondary data analysis from a larger study aimed at enhancing teachers' knowledge and abilities to implement problem-solving teaching. We identify and characterize three practices of silencing Black immigrant students in Chilean mathematics classrooms that damage their agency as knowers and doers of mathematics. Beyond language issues, we show that silencing is a form of anti-Black onto-epistemic violence that prevents Black immigrant students from being recognized as legitimate subjects of knowledge in mathematics classrooms.