Our customer service department answers many questions regarding our lime products for all the industries we serve. The questions range from lime applications and use to storage, shipping and handling. As a resource to our customers and website viewers, the listing below represents the most frequently asked questions.
- Can I store the lime outside?
- What is the shelf life of lime products in a storage tank?
- How many types of lime are there? I am confused by terms like “agricultural lime”, “quicklime”, slaked lime, hydrated lime. Are these all the same?
- What precautions should I take in handling quicklime or hydrated lime?
- What test methods are available to determine quality of lime and lime-based products?
- Where can I find information on physical and chemical properties of lime, bulk handling and storage of lime in bins and silos, solutions to common lime handling and flow problems, and descriptions of lime slaking equipment and lime slurry feeding systems?
No, quicklime and hydrated lime are very hydroscopic and can react with the moisture in the air. Quicklime and hydrated lime products should be stored in silos or at a minimum for a very short period under roof.
Lime products should be stored in silos or at a minimum under roof. Shelf life depends on the amount of exposure to air and the elements. Products stored in moisture proof silos can last several months or more if air infiltration can be kept to a minimum.
There are several types of products that are referred to as “lime.” Most lime is the natural chemical oxide (CaO), which is commonly referred to as lime, quicklime or burned lime. The name quicklime comes from an old meaning of “quick” as in alive or lively, since quicklime reacts vigorously with water. The name burned lime is used because quicklime is produced by burning limestone quarried or mined from the earth.
Quicklime resembles white pebbles and is usually produced in sizes ranging from 1-3/4 inch to 1/8 inch. Agricultural lime is usually ground limestone, which is the natural chemical calcium carbonate (CaCO3). Another type of quicklime is dolomitic lime, which contains about 40% magnesium oxide (MgO) in addition to calcium oxide.
Hydrated lime or hydrate is a dry powder of calcium hydroxide formed by mixing 1 part of quicklime with 1 part of water. Hydrated lime is produced at lime manufacturing plants and shipped to users in bags or in bulk trucks. Hydrated lime resembles talcum powder. Slaked lime, hydrated lime and hydrate refer to products formed from reaction of quicklime with water. Quicklime reacts with water to form calcium hydroxide [Ca(OH)2].
Lime slurry is a fluid mixture of calcium hydroxide and water formed by mixing 1 part of quicklime with about 4 parts of water. Users of lime usually produce this mixture themselves in equipment called lime slakers or they use hydrated lime slurrying equipment. Lime Slurry resembles a milk shake and is sometimes called “milk of lime.”
Quicklime and hydrated lime are both reactive natural chemicals, and like any chemical refer to (MSDS) Material Safety Data Sheets prior to use. An MSDS sheet for quicklime and hydrated lime can be obtained in our products listing.
The most widely used testing standards are the American Society of Testing and Materials (ASTM) and the American Water Works Association (AWWA). The ASTM Annual Book of Standards Volume 04.01 Cement; Lime; Gypsum is available for purchase from ASTM at www.astm.org. Methods for chemical analysis of lime and lime products are found in method C 25. Physical methods are found in method C 110. The AWWA standard B202-07: Quicklime and Hydrated Lime is available for purchase from AWWA at www.awwa.org
Where can I find information on physical and chemical properties of lime, bulk handling and storage of lime in bins and silos, solutions to common lime handling and flow problems, and descriptions of lime slaking equipment and lime slurry feeding systems?
An excellent guide to solutions on lime handling, storage, and usage is the booklet Lime: Handling, Application, and Storage. To purchase a copy of the guide go to the publication library available at the The National Lime Association website www.lime.org.