Process for Roasting Diatomaceous Earth Ore to Reduce Organic Content

A method for processing diatomite comprising roasting a diatomite feed in a first heating zone at a temperature ranging from about 850° F. to about 1600° F. to produce a diatomite product, and calcining the diatomite product in a second heating zone at a temperature greater than about 1600° F. to produce a calcined diatomite product,

• wherein a counter-current flow of gas flows from the second heating zone to the first heating zone, and
• wherein the second heating zone has a higher oxygen content than the first heating zone.

A system for processing diatomaceous earth ore comprising a first heating zone for roasting a diatomite feed at a temperature ranging from about 850° F. to about 1600° F. to produce a diatomite product, a second heating zone for calcining the diatomite product at a temperature greater than about 1600° F. to produce a calcined diatomite product, and a counter-current flow of gas flowing from the second heating zone to the first heating zone,

• wherein the second heating zone has a higher oxygen content than the first heating zone.

A method for processing diatomite, comprising roasting a diatomite feed having a loss-on-ignition of at least about 4% by weight at a temperature ranging from about 850° F. to about 1600° F. for a retention time sufficient to produce a diatomite product having a loss-on-ignition value of less than or equal to about 2% by weight.

A method for processing diatomite comprising roasting a diatomite feed having a first loss-on-ignition value and an impurity content of at least about 2% by weight at a temperature ranging from about 850° F. to about 1600° F. for a retention time sufficient to produce a diatomite product having a second loss-on-ignition value and a reduced impurity content,

• wherein the second loss-on-ignition value is at least about 50% less than the first loss-on-ignition value.