Four main uses of diatomite can be found in the United States; these applications are listed as follows: Filter media (56%), cement additive (15%), fillers (14%), absorbents (13%), and other (2%). The properties of diatomite that make it useful in these filter media (56%), cement additive (15%) fillers (14%), absorbents (13%), and other (2%).
For most applications the ore is either calcined or flux calcined in a rotary kiln to agglomerate the diatoms and produce the desired grade. This is an energy intensive process. The ore is heated to temperatures in excess of 1800 F. 80-90% silica, with 2-4% alumina (attributed mostly to clay minerals) and 0.5 to 2% iron oxide. There are a handful of rotary kiln operations in Lompoc, California and elsewhere to follow up.