About measuring the bulk density of a ceramic porous material by using the Archimedes method, you may check my answer at: https://www.researchgate.net/post/How_do_i_calculate_for_percentage_porosity_in_a_ceramic_material/1
On the difference between bulk density and apparent density for ceramic porous materials: https://www.researchgate.net/post/what_is_the_difference_between_Bulk_density_and_Apparent_density
These RG discussions may also possibly help: https://www.researchgate.net/post/Can_I_use_water_displacement_test_in_getting_the_density_of_lime https://www.researchgate.net/post/Use_of_Benzene_in_determining_the_density_of_glasses_by_archimedes_principle https://www.researchgate.net/post/How_do_i_determine_the_relative_density_of_my_ceramic_sample