What is cold lime soda process?

Cold lime softening process is used to reduce raw water hardness, alkalinity, silica, and other constituents. This helps prepare water for direct use as cooling tower makeup or as a first-stage treatment followed by ion exchange for boiler makeup or RO Reject recycle.

What is lime soda treatment process?

Lime softening (also known as lime buttering, lime-soda treatment, or Clark’s process) is a type of water treatment used for water softening, which uses the addition of limewater (calcium hydroxide) to remove hardness (deposits of calcium and magnesium salts) by precipitation.

What is the formula for lime soda process?

Basic principle: Lime [Ca(OH)2] and soda [Na2CO3] are the reagents used to precipitate the dissolved salts of Ca+2 and Mg+2 as CaCO3 and Mg(OH)2. The precipitated CaCO3 and Mg(OH)2 are filtered off. Lime reacts with temporary hardness, CO2, acids, bicarbonates and alums.

What are the limitations of lime soda process?

Disadvantage of Lime-Soda Process:

• For efficient and economical softening, careful operation and skilled supervision in required.
• Disposal of large amounts of sludge (insoluble precipitate) poses a problem.
• This can remove hardness only up to 15 ppm, which is not good for boilers.

Which coagulants is used in cold lime soda process?

Use of sodium aluminate as coagulant also helps the removal of silica as well as oil, if present in water. Cold L-S process provides water, containing a residual hardness of 50 to 60 ppm.

Why coagulants are used in cold lime soda process?

If process is carried out at room temperature it is called cold lime soda process. Coagulant is necessary because at room temperature precipitate is finally divided. But do not settle easily & cannot easily filtered. i) Reactions take place faster.

Which chemicals are used in lime soda process?

Chemicals normally used are lime (calcium hydroxide, Ca(OH)2) and soda ash (sodium carbonate, Na2CO3).

What is meant by Clark’s method?

Cold lime softening, also known as Clark’s process, is used to reduce raw water hardness, alkalinity, silica, and other constituents. This helps prepare water for direct use as cooling tower makeup or as a first-stage treatment followed by ion exchange for boiler makeup or RO Reject recycle.

What are the components of soda lime?

Soda lime consists of 94% calcium hydroxide and 5% sodium hydroxide with a small amount of potassium hydroxide (less than 0.1%). It has a pH of 13.5 and a moisture content of 14–19%. Some modern types of soda lime have no potassium hydroxide.

What are the advantages and disadvantages of lime soda process?

It is slow process because reactions during water softening takes place in very dilute solutions and room temp. It does not give soft water having residual hardness less than 50-60 ppm. It requires coagulant for setting particles of ppt.

Why coagulants are used in lime soda method?

Explanation: Coagulants helps in the formation of coarse precipitate.