Lime (material) ,
The Difference between Hydrated Lime & Quicklime
Production of lime is one of humankind's oldest chemical transformations, with roots going back before recorded history. There are two kinds of lime, quicklime and hydrated lime, which differ in their chemical composition and uses. Solid bars of quicklime were once heated in theatrical spotlights to produce an intense white light called the limelight. Hydrated lime once was used in outhouses to sanitize and kill odors. Today, both forms of lime are essential materials in industry, agriculture and construction.
Lime is a manufactured alkaline product created from limestone, or calcium carbonate. Limestone is crushed and fed into a huge rotary kiln. It is heated to about 2,000 degrees Fahrenheit by natural gas and combustion air to form lime by a process of controlled burning called calcination in which carbon in the limestone is driven off.
Quicklime Is Thirsty
Quicklime is calcium oxide. It is a white powdery substance that comes out of the lime kiln after calcination is complete. If the original limestone was a dolomitic rock that included magnesium carbonate along with the calcium carbonate, the dolomitic quicklime made from it will contain magnesium oxide along with the calcium oxide. Both pure quicklime and dolomitic quicklime have a strong chemical affinity to absorb water.
Slaking Quicklime's Thirst
Hydrated lime, sometimes called slaked lime, is quicklime to which water has been added until all the oxides of calcium and magnesium have been converted to hydroxides. The water has slaked quicklime’s thirst. Hydrated lime made from pure calcium oxide will be roughly 74 percent calcium oxide and 24 percent chemically combined water. Dolomitic hydrated lime will have about 48 percent calcium oxide, 34 percent magnesium oxide and 17 percent water. Hydrated lime is white and powdery.