Industrial Uses of Hydrated Lime

Industrial ingredient supplier Bell Chem’s hydrated lime (calcium hydroxide) is used across industries in myriad functions. Many customers wonder about the difference between quicklime and hydrated lime: hydrated lime and quicklime differ in reactivity, with quicklime (calcium oxide) being more reactive. Hydrated lime is simply quicklime with water added to convert oxides to hydroxides before the product is baked and pulverized (a process known as “slaking”). It is considered calcium hydroxide, or hydrated lime, at that time, although it is also known as slack lime, builders’ lime, or pickling lime. 

Hydrated lime is available in several strengths. The specific hydrated lime depends on the catalysts utilized and the type of quicklime. High calcium hydrated lime contains 72%-74% calcium oxide; dolomitic hydrated lime contains 46%-48% calcium oxide and 33%-34% magnesium oxide; and dolomitic hydrated lime (pressurized) combines 40%-42% calcium oxide with 29%-30% magnesium oxide. The remaining percentages are all water.

 Uses of hydrated lime are many and varied, including:

• Steel manufacturing: The largest scale use of lime is in the steel industry, where hydrated lime neutralizes impurities in plants where coke is a by-product. Steel plates are often sheathed in hydrated lime since it acts as an effective short-term barrier to oxygen corrosion.

• Chemical manufacturing: A variety of chemicals are manufactured with hydrated lime as a basic component. Included are bromide, caustic soda, fluoride, magnesia, lactate, nitrate, oleate, and stearate. Many organic and inorganic calcium salts, such as calcium carbide, calcium hypochlorite, calcium magnesium acetate, and calcium phosphate, begin production with hydrated lime. Hydrated lime also plays a role in citric acid purification.

• Flue gas treatment: Hydrated lime catalyzes particles emanated after combustion in cement plants, coal fire plants, glass industries, and other incendiary plants. Acidic pollutants normally released into the environment, such as hydrogen fluoride, hydrogen chloride, sulfur dioxide, selenium, and fine particulate matter are captured by hydrated lime’s anions, eventually rendering them into calcium sulfate.

• Sugar production: Both cane and beet sugar rely on hydrated lime to react with impurities and elevate pH. Hydrated lime also removes impurities in the manufacture of maple syrup, sorghum, or other viscous forms of sugar. Carbonation before the final product is packaged removes excess lime.

• Acid reduction: As milk is separated into cream and skimmed milk, lime water is added to the cream portion prior to producing butter to reduce the acid content. Lime added to the remaining milk produces either lactic acid, when combined with a low pH chemical, or calcium lactate, a boon for medicinal supplements.

• Baking powder creation: Baking powder (monocalcium phosphate) is a reaction of phosphoric acid with high calcium lime. 

• Masonry binding: Hydrated lime is used to bind with sand to form plaster and stucco. Adding 15% hydrated lime to cement significantly reduces shrinkage and cracking. Road and building foundations, earthen dams, and airfields all rely on hydrated lime. 

• Paint formation: Limewash painting is achieved when water and pigment are added to hydrated lime to form a paste-like consistency before it is applied. 

• Soil amending: Adding basic hydrated lime to acidic soil stabilizes the pH for superior plant growth.

Bell Chem is an industrial ingredient supplier based in Longwood, FL (just north of Orlando) with hundreds of products stocked in their 50,000+ square-foot warehouse, including hydrated lime. You can expect the highest quality products, expedited shipping options for maximum efficiency, and unrivaled personalized customer service. Let our knowledgeable and friendly customer service representatives and accounting staff personalize all your needs by either calling 407-339-BELL (2355) or by sending us an online message.