Calcium Soap Greases:

Tallow (animal fat) based calcium greases were the earliest lubricants developed during 1845. As a result, calcium greases were relatively inexpensive to manufacture and are still in use since then.[3]. While there are three types of calcium greases but anhydrous calcium grease is the most economical multipurpose grease. Besides, the other two greases are hydrated calcium and calcium complex. In addition to multipurpose anhydrous calcium, hydrated calcium or lime grease is one of the most economical greases for general-purpose wet applications.

Three common types of calcium greases:

  • Hydrated calcium grease (lime grease)
  • Anhydrous calcium Grease
  • Calcium complex  

Hydrated calcium soap grease

Hydrated calcium grease has mineral oil, animal fat (tallow), and lime in its composition. Grease has a 90°C (194°F) dropping point, whereas the useable temperature is around 65°C (149°F). Still being manufactured on a large scale, it is one of the most economical greases.  Due to the chemical reaction of hydrated lime with tallow, lime greases need water to retain their grease structure. A small amount of water acts as a stabilizer. Lime greases have limited use because of lower useable temperatures and the need for water to stay as grease.

Uses (applications) of hydrated calcium grease

  • Machines in a wet environment
  • Agricultural and farming machinery exposed to water
  • Water pumps
  • Non-bearing axles
  • Chassis lubrication

Advantages of hydrated calcium (lime) grease

  • Smooth structure
  • Good low-temperature properties (depending upon the base oil)
  • Excellent water resistance (don’t form an emulsion with water)
  • Good adhesion (adhere to surface applications)
  • Pumpable

Disadvantages of hydrated calcium lime grease

  • Low drop point 90-100°C (195-210°F)
  • The maximum working temperature is 65°C (149°F).
  • Not suitable for high-speed application (bearings)
  • Grease structure breaks without water
  • Poor storage stability
  • Poor shear/mechanical stability

Anhydrous calcium soap grease 

Anhydrous calcium grease is an economical multipurpose grease. Calcium 12-Hydroxy Stearate, or anhydrous calcium grease has 12HSA (12-hydroxystearic acid) instead of animal fat (tallow/stearic acid) as a thickener. As a result, 12HSA eliminates the need for water in calcium greases. In the same way, it is also possible to use blend of 12HSA and HCO (hydrogenated castor oil) or stearic acid with an 85:15 ratio. The grease has a 150°C (300°F) dropping point, good thermal stability, excellent water resistance, and good mechanical stability. Therefore, it is the best multipurpose grease for applications where equipment running at the ambient temperature or up to 90°C (194°F) max. Theoretically, it is okay for up to 110°C (230°F) because of 150°C (300°F) dropping point, but as layman selection criteria use it for non-powered machinery.

Composition/formulations of anhydrous calcium grease

Learn More:

Composition/formulation of multipurpose NLGI-2 anhydrous calcium grease (target ISO VG 110)
Components Percent Wt
Base Oil (Group I SN600) 75%
Bright Stock 5%
12-Hydroxystearic Acid 11.9%
Hydrogenated Castor Oil 2.1%
Calcium Hydroxide 2%
Additives 4%
Composition/formulation of multipurpose NLGI-2 anhydrous calcium grease (target ISO VG 220)
Components Percent Wt
Base Oil (Group I SN600) 41%
Bright Stock 39%
12-Hydroxystearic Acid 11.9%
Hydrogenated Castor Oil 2.1%
Calcium Hydroxide 2%
Additives 4%

How to make grease:

The process to make anhydrous calcium soap grease. See the above example for composition or formulation.

1. Charged 15% of the total base oil to an open kettle. 

2. Heat is applied to reach 50-60°C (122-140°F) with stirring.

3. 12-hydroxy stearic acid and hydrogenated castor oil added (the preferred ratio is 85:15 up to 50:50).

4. Reached 80°C (176°F) with continuous stirring to melt the acids. 

5. At 80-90°C (194°F), the slurry of calcium hydroxide is added slowly to the kettle over 20 minutes. 

6. Added the calcium hydroxide slurry; 30 minutes further mix time is completed, maintained below 100°C (194°F) temperature to avoid foaming.

7. Following the 30 minutes mixing time, the temperature increased stepwise to complete the reaction and water removal.

8. At 110°C (230°F), the heat increased to initiate the temperature ramp to the 140°C (284°F) process maximum. A portion of the base oil is added multiple times during this process.

9. At 140-145°C (284°F) temperature stage, cooling oil is applied at a slow, controlled rate. 

10. Cooling started, below 90°C (194°F), antioxidants, EP, and other additives added. The grease is milled, and the penetration and dropping point tested. 

11. Final adjustment base oil added to achieve the desired grade.

Comparison and specification of calcium greases
Description Hydrated Calcium Grease Anhydrous Calcium Grease
Dropping Point 90°C (194°F) 150°C (300°F)
Useable Temp °C Max 65°C (149°F) 110°C (230°F)
Appearance Fibrous Buttery
Good for Use as Economical General-Purpose Economical Multi-Purpose
Water Resistance Good to Excellent Excellent
Work Stability Fair to Good Good to Excellent
Oxidation Stability Poor to Excellent Fair to Excellent
Rust Protection Poor to Excellent Poor to Excellent
Oil Separation Poor to Good Good

Uses (applications) of calcium 12-hydroxystearate grease

  • Multipurpose grease for wet environment
  • Wet industrial machinery
  • Sewage plant and machinery
  • Agricultural, farming machinery exposed to water, tractors, mine cars, and textile machinery
  • Water pumps and bearings
  • Slow-moving axle grease
  • Chassis lubrication

Advantages of calcium 12-hydroxystearate grease

  • Smooth translucent structure
  • Good low-temperature properties (base oil-dependent)
  • Available in EP (extreme pressure)
  • Excellent water resistance (don’t form an emulsion with water)
  • Good adhesion (good for adhere-to-surface applications)
  • Excellent shear stability
  • Pumpable

Disadvantages of calcium 12-hydroxystearate grease

  • Low drop point of 150°C (302°F)
  • The low continuous use temperature of 52 to 66°C (125 to 150°F) up to 90°C(194°F). The absolute max is 110°C (230°F)
  • Fair storage stability
References:

[1] Dropping Point of Lubricating Grease

[2] ASTM grease definition

[3] History of Automotive Lubrication SAE Technical Paper 961949 By SQA Rizvi

[4] NLGI Grease Guide

48 Responses

  1. Hi sir
    I have some question.
    1. what should be the highest temperature for making tallow base grease …?
    2. when should i stop heating i mean does grease become tight when its water evaporates ..?
    plz assist me step by step about mfg process of tallow base calcium grease.

  2. Need to know what role does caustic soda play in the formation of Lime based grease. We use caustic soda (lye) for forming the Calcium Greases.

  3. Hi sir I m prabhat
    I liked your information and I am working in grease department Even I am developing in lab

    I need your help sir
    To develop more
    If I get this chance to work with you
    Really I am feeling I am very lucky I want to work with you on some formula and development.

    1. Hi prabhat

      are you working on grease mfg..?

      can you assist me regarding calcium base grease manufacturing if you have grease production knowledge.

  4. Hlo sir
    Can I get any video of anhydrous calcium grease or hydrated calcium grease manufacturing process.

      1. Please share formulation for calcium & lithium complex if possible. need to start production in my plant.

    1. At 110°C (230°F), the heat increased to initiate the temperature ramp to the 140°C (284°F) process maximum. A portion of the base oil is added multiple times during this process. — This is process —my problem soap not smooth / It lime+12HSA gathered into small lumps

  5. Hello!
    Have some questions about formulation and blending process.
    -How is shaft speed affect yield.
    -What is the difference between 2-HSA and HCO? And why use both in grease blending as raw
    materials?
    -Any required ratio of LiOH:12 HSA:HCO to get maximum yield.
    -How is intermediate and final temperature & ramp time during grease blending affect yield and grease properties?
    -How hold time for final temp before addition base oil for cooling affect yield and grease properties?
    -How does start quantity base oil affect yield and grease properties?
    -How does cooling rate affect grease properties?
    If you provide more services, kindly contact me via the mentioned e-mail.
    Thanks.

    1. Yes, To manufacture calcium soap grease, hydrated lime (calcium hydroxide) and water are added to a stirring mixture of fat (animal fat), and oil. For making hydrated calcium grease (lime grease), the usual fatty component is tallow. In case of an open kettle, the temperature must be below 100°C, the boiling point of water. If animal fat alone is used as the starting material, the addition of a certain amount of water is necessary to facilitate saponification. Animal fat base calcium grease required the presence of at least 1–2 % water to maintain grease structure.

  6. Hello,
    I tried to make fat based on calcium, stearic acid, hydrogenated castrol oil, and an improver, but the final texture was very very soft, so, what’s the matter please.

    1. Please share your formulation including base oil and type of improver. There are many factors that can lead to low yield or loose grease.

    2. Try to make grease with hydrogenated caster oil only, no stearic acid. With stearic acid you may need 16-22% fat to make NLGI 3 grease.

    1. Pressure vessel is better but open kettle is completely fine too. Most manufacturers use open kettle for anhydrous grease manufacturing.

  7. Thanks .
    Very useful formulation of anhydrous calcium grease.
    If we add 5% sebacic acid with 12HSA then its drop point would not increase 150c to 150c.
    PLEASE SUGGEST ME.
    Thanks and Regards
    D .Ghosh.

    1. Commercial calcium complex greases contain complex soap of three acids.
      1- Soap of a higher fatty acid
      2- Soap of lower fatty acid,
      3- Soap of aromatic fatty acid.
      Preferred higher fatty acids are (12-HSA) 12-Hydroxystearic acid, and hydrogenated castor oil (HCO). similarly, benzoic acid is a choice for aromatic fatty acids. Highly preferred lower fatty acid is acetic acid. You can use alternatives, but 12-HSA, benzoic acid, and acetic acids are economical.
      Calcium complex greases can replace lithium and lithium complex greases in many applications but are inferior to lithium greases in terms of dropping point, mechanical stability, and heat resistance. Calcium complex greases tend to harden during long-term storage and are not recommended in some bearings. Surface hardening is a problem in many calcium complex greases.
      Calcium sulfonate complex grease is a superior alternative to lithium and lithium complex grease. Due to the record high price of lithium hydroxide, Calcium sulfonate greases are gaining popularity.

          1. Hi
            I am from chennai, India.
            We make both lithium and calcium grease.

            Looking for calcium sulphonate grease formulation.

            Thanks
            Bajnath Singh

        1. Dear Sir,
          I want to Make calcium base Grease.
          I Have Palmitic Fatty acid, ca(oh)2 and mineral Oil.

          Please Help me make calcium base Grease.
          Thanks,
          Wimalasena

          1. The complete process for the manufacturing of anhydrous calcium grease is given in the above article. If you still have issues please provide details so I can give you a solution.

        2. Manufacturing calcium sulfonate complex greases is not easy and requires special grease-making equipment. We will publish articles for calcium sulfonate complex greases very soon. Stay updated for the latest articles at this website.

          1. can i use hco & lithium and Azelaic acid only, and when should i use Azelaic acid means addition temperature etc??

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