36 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



LIME. 



Lime or "quick lime" is chemically an oxide of calcium or 

 calcium and magnesium.' It is formed ordinarily by burning lime- 

 stone, although shells and other calcium carbonates may be used 

 for the same purpose. Limestone when burned gives up carbon 

 dioxide. The residue after burning forming a lime, consists of a 

 calcium oxide, when a pure calcium carbonate limestone is used; 

 or of calcium and magnesium oxide when a dolomitic limestone is 

 used. The reaction in the case of a pure limestone is as follows : 

 CaC03 when heated breaks up into Ca0+CO2, In the case 

 of dolomitic limestone a magnesium oxide as well as calcium 

 oxide is formed. 



The character of the lime varies according to the amount 

 of magnesium present in the limestone from which it is made. 

 Peppel* offers the following classification of the ordinary or 

 "white limes", including in that term limes containing not more 

 than 5 per cent of sandy and clayey impurities : 



(i) High-calcium; or "hot" or "quick" limes. Made from limestones 

 containing not less than 85 per cent, of carbonate of calcium. 



(2) Magnesium limes. Made from limestone containing between sixty- 

 five and eighty-five per cent, carbonate of calcium and between ten and thirty 

 per cent, of carbonate of magnesium. 



(3) Dolomitic, or "cool" or "slow" limes. Made from limestones con- 

 taining more than thirty per cent, of carbonate of magnesium. 



These limes differ slightly among themselves. The high cal- 

 cium or "hot" or "quick" limes set more quickly, while the mag- 

 nesium and dolomitic limes set more slowly. Limes thus serve 

 different purposes, the high calcium limes being used when a quick- 

 setting lime is desired, while the other limes are used when slow- 

 setting limes are desired. After calcination, the lime may be 

 placed on the market as quick lime, or it may be slaked and placed 

 on the market as hydrated lime, Hydrated lime is said to be desir- 

 able for certain purposes since tlie lime if properly slaked breaks 

 up into exceedingly fine powder. 



The total quantity of quick and hydrated lime made in Florida 

 during 1913 amounted to 18,917 tons, valued at $100,335. The 

 companies reporting production of lime in Florida during 191 3 

 were as follows : 



*Bulletin No. 4, 4th Series, Ohio Geol. Survey, p 254, 1906. 



