Where is limestone used for?
It is the raw material for the manufacture of quicklime (calcium oxide), slaked lime (calcium hydroxide), cement and mortar. Pulverized limestone is used as a soil conditioner to neutralize acidic soils (agricultural lime). Is crushed for use as aggregate—the solid base for many roads as well as in asphalt concrete.
To make Portland cement—the most common type of cement—powdered limestone is heated in a rotary kiln. As a source of calcium, it joins with powdered clay to produce a product called clinker, which is then ground with a source of sulfate, like gypsum. It is mixed with water, sand and crushed rock to create concrete.
- Limestone is an alkaline agent with the ability to neutralize, or partially neutralize strong acids. The neutralization process occurs when strong acids, in intimate contact with limestone chips, react with Calcium Carbonate (CaCO3, the primary constituent of limestone) to form water, carbon dioxide, and calcium salts.
- The plasticity or workability of the mix is better. When hydrated lime is added to the mix, the sand and the cement do not separate. The final mortar also is more waterproof. Shrinkage cracking often can be eliminated or minimized when hydrated lime is used.
- Limestone is most often mined from a quarry. However, underground limestone mines are found at places in the central and eastern United States, especially in and near cities. Underground mining of limestone has some advantages over surface quarrying and will probably increase in the future.
Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal, and fecal debris.
- Limestone is formed in two ways. It can be formed with the help of living organisms and by evaporation. Ocean-dwelling organisms such as oysters, clams, mussels and coral use calcium carbonate (CaCO3) found in seawater to create their shells and bones.
- Lime is a soil amendment made by grinding limestone, a naturally occurring type of rock that is very high in calcium. Two types of lime are commonly used in lawns and gardens, agricultural lime and dolomitic lime. Agricultural lime, also sold as garden lime, is made from calcium carbonate.
- Limestone is an organic, sedimentary rock. Limestone is formed in layers - called bedding planes. These bedding planes contain vertical cracks called joints. Joints and bedding planes make the rock permeable.
Soil acidity is one of the factors that can influence plant growth and can seriously limit crop production. By spreading agricultural lime onto the paddock or soil, the calcium carbonate content of the limestone is capable of neutralising some of the acid in the soil.
- Lime, particularly quicklime, is an alkaline material that is reactive in the presence of moisture. Workers handling lime must be trained and wear proper protective equipment. Eye Hazards—Lime can cause severe eye irritation or burning, including permanent damage. Inhalation Hazards—Lime dust is irritating if inhaled.
- Lawn grasses tolerate a pH of between 5.5 and 7.5. It takes 20 to 50 pounds of ground limestone per 1,000 square feet to correct a mildly acidic lawn. Strongly acidic or heavy clay soil may need as much as 100 pounds. In small garden beds, you can estimate the amount of lime you need with the following information.
- Causes of Soil Acidity. Soil acidity can be caused by a number of factors: Acidic soils tend to be high in iron and aluminum oxides, as they are the slowest minerals to weather in soil. Aluminum in these increasingly acidic soils is solubilized and will combine with water to release additional hydrogen ions (acidity).
Updated: 3rd October 2019