Lumps form in cement silos due to several factors: 1) High temperature cement being conveyed into silos, causing dehydration and moisture movement; 2) Entry of humid air which hydrates fine cement; 3) Rough silo surfaces allowing hydration and dislodging of cement. To prevent lumps, the document recommends: reducing cement temperature to below 80°C when conveying; reducing storage time; improving silo ventilation; and adding anhydrate gypsum to slow hydration. Proper silo coating and maintenance can also help reduce lumps forming over time in cement silos.