Thermally and oxidatively stable solid lubricants

A recirculating powder lubricant delivery system having improved oxidative stability wherein said recirculating lubricant is a solid lubricant selected from the group consisting of molybdenum disulfide, graphite and graphite fluoride, wherein said solid lubricant is encapsulated by spray drying from a suspension comprised on a total weight of solids basis of from about 50% to about 75% of said solid lubricant, from about 3% to about 30% of an alkali metal silicate and from about 15% to about 45% of a water soluble acid phosphate.

A recirculating powder lubricant delivery system having improved oxidative stability wherein said recirculating lubricant is a solid lubricant selected from the group consisting of molybdenum disulfide, graphite and graphite fluoride, wherein said solid lubricant is encapsulated by spray drying from a suspension comprised on a total weight of solids basis of from about 50% to about 75% of said solid lubricant, from about 1% to about 30% of an alkali metal silicate, from about 10% to about 45% of monoaluminum dihydrogen phosphate and from about 2% to about 5% of fumed alumina.