Abstract: Process for making thermally stable macro porous spheres with or without central core cavity includes steps of homogenizing dry pulverized selective constituents with or without burnable core particles and with <25% combustibles; sprinkling over pan pelletizer wetted with PVA aqua sol binder and rolling to form spheres having <25% moisture and dry compacting in pelletizer before oven drying at 90-100° C. until moisture and core particles are partially destroyed and sintering under rotary motion of the spheres for 45-60 minutes at 1350-1380° C. before being rapidly cooled down to ambient temperature and sieving and recovering therefrom low-to-high temperatures >90% loose fill macro porous spheres for catalyst and moulded bricks/monoliths forming refractory insulation applications.