calcium content in lithium EP grease

[majid]

Hi
I find about 1400 ppm Calcium in Lithium EP grease. Why producers add Calcium to this kind of grease. This is not LI-Ca grease and it is only Lithium EP grease. What is the function of calcium in Lithium Grease? What is the source of Calcium? Is it additive like TBN booster or another form of Calcium component?

Thank you

 

[MolaKule]

Grease Technology Part I

 

[RDMgr]

Some EP greases, including some lithium or lithium complex greases, may contain calcium in the form of calcium carbonate for EP. Another potential source is a neutral or overbased calcium sulfonate rust inhibitor. An overbased calcium sulfonate may be used as a rust inhibitor and an EP additive. 5.6% of a 2.5% OB calcium sulfonate would yield 1400 ppm of calcium, great rust protection, moderate EP and possibly improved water resistance.

 

[majid]

Thank you RDMgr.
Where is the source of OB calcium sulfonate? Is it from calcium sulfonate TNB booster as an additive or calcium sulfonate complex grease which is added to lithium grease?

 

[majid]

Thank you

 

[RDMgr]

A neutral calcium sulfonate would be for rust prevention. An OB calcium sulfonate would be for rust prevention and possibly an EP boost. The excess of calcite might be enough to boost EP. In a grease it isn't likely for the TBN benefit. Acidification is not usually a problem in multipurpose greases.

 

[majid]

Dear RDMgr
Many thank for your useful information..