Lime is extensively used to neutralize acidity. Hydrated lime, quicklime or dolomite lime is mixed with water to give alkaline slurry which neutralises the low pH of acids.Milk of lime can also be used to avoid the need for slurring equipment. Often insoluble calcium salt is precipitated during the reaction; this can help to remove impurities from the system.
Lime is extensively used to neutralize acidity. Hydrated lime, quicklime or dolomite lime is mixed with water to give alkaline slurry which neutralises the low pH of acids.Milk of lime can also be used to avoid the need for slurring equipment. Often insoluble calcium salt is precipitated during the reaction; this can help to remove impurities from the system.
Quicklime when mixed with cement, sand or PFA, water and aluminium powder, it gives a slurry compound that rises and then settles down to form honeycomb structured blocks that have excellent thermal and sound insulation properties. This is how the process happens. The heat generated when quicklime reacts with water in alkaline conditions combined with aluminium powder generates hydrogen bubbles that cause the blocks to rise. Subsequent thermal energy created during the process helps the slurry compound to settle. The blocks are then heated in an autoclave, which promotes reactions between calcium and silicates in the sand or PFA and gives extra strength.Dolomite lime and/or modified quicklime can be added to reduce excessive shrinkage or cracking.
Calcium Carbonate, quicklime and hydrated lime are used to adjust the pH balance in soils and give them optimum growing conditions thereby improving crop yield. The use of quicklime, hydrated lime and / or blends of these with Calcium Carbonate helps speed up pH adjustment that helps treat adverse soil conditions.
Quicklime is used as a flux in smelting of copper, lead, zinc and other metals from their ores. Quicklime reacts with silica, alumina and other impurities to form a molten slag, whichcan be easily removed during the process. Slaked lime is used during the extraction of aluminium from bauxite.
A vast variety of organic and inorganic sludge can be treated using quicklime or dolomite lime in order to increase the solids content. Biological sludge can be sanitised by the increase in temperature and pH obtained by adding these materials.
Calcium Silicate Bricks can be made by mixing quicklime or hydrated lime with silica sand. The bricks are pressed into shape and then heated in an autoclave, which promotes reactions between calcium and silicates in the sand and gives extra strength.
One of the main applications of lime, dolomite lime and their derivatives is as a raw material in the manufacture of commonly used chemicals. The two main areas of usage of lime are production of inorganic chemicals and oil additives. Lime or its derivatives are essential building blocks in the manufacture of many inorganic salts such as Calcium Phosphate - a toothpaste additive, Calcium Citrate - a food and drink additive and Calcium Nitrite - an additive for sludge treatment. Hydrated lime is widely used in the production of oil additives for lubricants specifically sulphonates, phenates and salicylates. The oil additives are used as detergents that improve engine life in cars, ships etc.
Contaminated land can be treated using lime, dolomite lime and / or lime binder mixes to adjust pH and immobilise sulphates, phosphates and heavy metals.
During any manufacturing process that requires a 100% dehydration, like PVC, Plastics or Rubber, quicklime finds its entry as a fool proof desiccant. Quicklime will react with any free water present to form hydrated lime. This removes the water from the system and can be useful when dealing with products that are heated during the manufacturing process.
Flue gases and acid effluents containing oxides of sulphur can be treated by introducing limestone, chalk, quicklime or hydrated lime as a powder or slurry, promoting a reaction to form insoluble calcium sulphate or gypsum that can then be collected separately. If carried out under prescribed conditions, this process produces gypsum as a by-product which is off immense commercial value.
Hydrated lime and/or milk of lime are used to remove temporary hardness from drinking water and to adjust its pH for optimum purification conditions. They precipitate out the heavy metals in the form of insoluble hydroxides.
Many industrial processes use acids or acidic species as part of the manufacturing process. Stringent legislation has made it mandatory that the acidic effluent be treated before it is discharged. The common method is to treat effluents on site in a treatment plant where lime plays a crucial part in the neutralisation of the acidic species. And Lime is the versatile solution to this application. Lime also has the additional benefit of removing the toxic heavy metals present as an insoluble salt which is removed by filtration.
Hydrated lime or quicklime is used to adjust pH of water systems to give it an optimum environment for effective breeding of fish. Quicklime can also be used in pest control, such as starfish and parasites.
In Flue Gas Treatment, hydrated lime is sprayed into the flue gas stream in the form of a dry powder, or a suspension in water. This enables reaction with any pollutants (gases such as hydrochloric or sulphuric acids or heavy metals) to form insoluble salts. The spent sorbent is then removed by large filter units before cleaned gases are emitted into the atmosphere. On larger sites, quicklime can be slaked in site to produce a hydrated lime suspension.
Hydrated Lime is utilised in fruit stores to aid the capture of Carbon Dioxide emitted from ripening fruits.This process keeps the fruits fresh over a longer period.
The continuing demand for power has resulted in an increase in the burning of fossil fuels. Many such fuels contain sulphur and the resultant emissions into the atmosphere are the principal cause of acid rain. Other sources of acid rain can be incinerators whether they burn municipal or industrial waste, clinical waste, animal carcasses or natural fuels. Almost all incinerators around the world have utilised lime as a means of removing harmful gases for many years and proved lime to be cost effective, efficient and sustainable.
Hydrated lime helps to de-hair and "plump" hides before the tanning process is initiated.
Lime Wash is a traditional method of painting walls that provides a colour base and allows the masonry to breathe. It also sanitises the surface. Many traditional buildings use limewash wall colours even now.
Lime Putty has been used in construction for many centuries. It reduces absorption of water into masonry and allows the walls to breathe. It also gives plasticity to the wet mortar and helps it to penetrate into fine crevices, forming a strong even bond thereby ensuring joints of sympathetic tensile and compressive strength. The best quality lime putty is made by slaking quicklime. This method of building is widely used for Historic Building Conservation and is becoming ever more popular in modern applications.
By using the lime cycle, we can increase the purity and consequently the brightness of calcium carbonate by calcining, hydrating and then re-carbonating back to calcium carbonate. This process is used to make fillers and coating products that are used in the paper industry extensively. The caustic properties of hydrated lime are utilised in the sulphate process during the manufacture of paper and pulp.
A wide number of organic and inorganic sludge can be treated using quicklime or dolomite lime to increase solids content. Biological sludge can be sanitised by the raise in temperature and pH obtained by adding these materials. Bio solids treatment up Advanced Treated is achievable with this method.
Although widely known as Soil Stabilisation, there are a number of distinct processes that which can be carried out by adding quicklime to waterlogged, clay bearing or contaminated land. Improvement is the first step in the process, which is drying out of water bearing material by the heat generating reaction with quicklime; this also converts some of the free water to hydrated lime. Using this process, it is possible to convert an unworkable site into a solid working platform within a short time.
Dolomitic stones can be used as a coolant and slag modifier in BOS steelmaking. Dolomitic lime can be added to BOS and Electric Arc Steelmaking processes to modify slag viscosity, protest refractories and to help flux the lime. It is also used to aid with the removal of impurities.
Sugar manufacturers use lime in order to precipitate out impurities from beet and sugar cane extract. Lime is also used to neutralise the odours which are generated during beet washing and transport.
Hydrated lime suspensions or milk of lime is used to neutralise and coat wire after it is acid cleaned.This acts as a slip agent to reduce friction during the drawing process and helps protect the wire during storage.