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Lime Information & Resources

 

Safety

Like most chemicals in common use, hydrated lime (Ca(OH)), unslaked lime (CaO), and dolomitic lime (CaOMgO) are safe to work with provided a few simple precautions are taken.

  • All types of lime and dolomite are strongly alkaline (caustic).
  • Hydrated lime can cause drying and irritation of the skin.
  • Unslaked lime and dolomitic lime react with moist skin and can cause skin burns.

When lime comes into contact with water it causes a reaction that gives off heat, which results in steam generation and temperatures sometimes in excess of 100°C.

Care should therefore be taken when opening manhole covers on slakers, or when using water to flush away spillage to avoid steam burns.

When working under these circumstances the wearing of long sleeved overalls, gloves, safety boots and safety goggles is essential.

Protective Measures

If the following recommendations are followed the possibility of burns or skin irritations will be minimised.
  • Wear long sleeved overalls and laced up boots
  • Eye protection:
    Wear snug fitting dust goggles when dust levels are high (padded where they contact the skin). Provide an eye wash station. At minimum, sterile water in eye wash bottles.
  • Mouth, nose and lung protection:
    A government mining engineer / Department of Labour approved dust mask must be worn when dust levels are high. (Approved standard FF2/NIOSH N95). Care should be taken to avoid perspiration where the mask contacts the skin.
  • Wear gloves of leather or plastic when handling lime. The gloves should cover the sleeves and have elasticised wrists. These will protect the skin on the hands from burns and drying out.
  • A cheese-cloth scarf worn around the neck absorbs perspiration and prevents lime dust entering the overall.
  • A dust cap worn under the hard hat extending over the overall collar prevents lime dust from falling down the back.
  • Protective creams: A barrier cream such as Momar may be used on exposed skin. If properly applied it forms a thin protective film, which is easily removed by washing after work.
  • All clothing should be washed at regular intervals. This removes lime dust, which builds up and can dry out the skin.

After Work

A bath or shower after work is essential.

Personal hygiene is most important and thorough washing of the body is advisable as soon as possible after contact with lime.

First Aid

  1. Skin irritation: wash with soap and water.
  2. Burns: as above but obtain medical attention.
  3. Lime in eyes: Flush out immediately with lots of water. Obtain medical attention after washing eyes.

Clean Up

  • Unslaked lime spillage should be swept up or vacuum cleaned.
  • Do not use water if large quantities of lime have to be cleaned up.
  • An area should be hosed down only if small amounts of unslaked lime dust are to be removed.
  • Where possible return spillage to the process.
  • Where dumping is necessary this must be done safely, to accepted standards and be authorised by local management.

Bulk Bags

Bulk bags are designed for single trips only and are to be disposed of responsibly after emptying.
The bags are not to be used to load other products because of the dangers of:
  1. Reaction with remaining lime.
  2. Incorrect use of the new product because the bag is marked lime.

Tanker Off-Loading

During tanker off-loading the system is under pressure therefore the following precautions should be taken.
  1. In-plant personnel to ensure that pipework and couplings are in a good condition.
  2. The number of people in the off-loading area should be kept to a minimum.
  3. The off-loading crew is to follow their correct off-loading procedures.
  4. Once off-loading commences the off-loading crew should stand back from the flexible pipe.
  5. People in the off-loading area should wear full safety equipment at all times, namely:
    - long sleeve overalls.
    - hard hats.
    - safety boots.
    - safety goggles.
    - dust masks - gloves.
  6. Pipes must not be decoupled until the vessel has been completely depressurised.

Additional Resources

Description Link

Summarises lime treatment of acidic gases for air pollution control (flue gas treatment).

Read -articel (1)

Summarises the use of lime for treatment of acidic wastewater.

Read -articel (2)

In-depth description of acid neutralisation with lime for environmental control and manufacturing processes.

Read -articel (3)

Evaluation of FGD processes, dry scrubbing vs wet scrubbing

Read -articel (4)

An introduction to proven and effective methods used to add hydrated lime to asphalt to reduce stripping and enhance performance (2003, 14pp, 1.3 MB).

Read -articel (5)

Overview of lime stabilisation procedures and benefits. (Updated 2001)

Read -articel (6)

Lime in soil stabilisation

Read -articel (7)

Provides detailed overview of construction steps to use lime for soil drying, temporary modification, or permanent stabilisation. Discusses pros and cons of alternative applications. Focuses on highway pavements, but non-highway applications also addressed. 11th ed., 2004, 41 pp.

Read -articel (8)