dissolution reaction of carbon dioxide with rocks

Hello everyone, I am a beginner, I want to simulate the dissolution reaction of carbon dioxide with rocks, but I don’t know how to achieve dissolution, do I need a REAXFF force field, and probably what command can I achieve dissolution? Thank you

This is less a question about LAMMPS but about how to do your research. That makes it off-topic for this forum category and rather a topic for discussion with your adviser or tutor. You cannot learn how to do research from an online forum.
The step that any decent adviser would recommend is to first survey the published literature for any studies that have done similar things. As a beginner, you should not start something new without guidance.