ENGLISH CORPORATE HOME ABOUT US SUSTAINABILITY MARKETS & SOLUTIONS INNOVATION PEOPLE AND CAREERS CONTACT Home All about Lime & Minerals Glossary ALL ABOUT LIME & MINERALS LIME AND MINERALS IN YOUR DAILY LIFE WHAT CAN THEY DO? WANT TO KNOW MORE ABOUT… PRODUCT CATEGORIES MANUFACTURING PROCESSES HOW IS CLAY MANUFACTURED? LIMESTONE ORIGINS LIME THROUGHOUT HISTORY GLOSSARY GLOSSARY TERM DESCRIPTION AAC Aerated Autoclaved Concrete, AAC, is used for building and is also commonly called cellular concrete or "Aircrete" Absorb In flue gas treatment processes, hydrated lime captures acidic pollutants from flue gas (HCl, SO2, SO3, HF) by absorption. Acidification Acidification is the reduction of the pH of soil, waterways and lakes. Adsorb In flue gas treatment processes, this capture is an acid-base chemical neutralization, producing salts such as CaCl2, CaSO4 or CaF2 Aggregate Aggregate is a granular material used in construction. The most common natural aggregates of mineral origin are sand, gravel and crushed rock. (< 95% CaCO3) Air Lime Calcic or dolomitic limes are called air limes because they combine and harden with the carbon dioxide present in the air. Annular Shaft Kiln The Annular Shaft Kiln (ASK) is one of the numerous types of lime kiln technologies. Starting with a vertical shaft, external combustion chambers have been installed at two levels. There are either 4 or 5 chambers on each level, depending upon the size of the kiln. An internal cylinder creates an annular zone through which the charge passes, hence the name “annular kiln”. The inner cylinder is set under negative pressure; this creates the conditions for a recirculation loop of gas flow inside the kiln, which increases the effective zone of calcination compared to other vertical kilns. This allows production of a more reactive lime, as compared to lime produced in classic shaft kilns. Bind In building market processes, lime reacts either with CO2 or with the silica in sand to form calcium carbonate or hydrated calcium silicates. This produces strong and durable bonds. Lime reacts with pozzolanic materials to bind mortars and plasters and leads to a hard structure. Blast Furnace Blast Furnace technology is used in the steel making process to reduce iron oxide into metallic iron (also called pig iron) and to remove impurities from the iron ore. BOF - Converter Basic Oxygen Furnace technology is used in the steel making process to transform pig iron into steel, removing carbon and impurities. Calcination Calcination is heating material to release volatile constituents or change the crystal structure. Calcined Products - Oxides : Quicklime, dolime Calcite Calcite is the crystalline mineral consisting of calcium carbonates. Calcium Carbonate CaCO3 (limestone) is an abundant mineral on earth. Lhoist selects the purest deposits that are suitable for a wide range of applications. Clay - Ball Clay Ball Clay – is a disordered kaolin-like clay that is the water deposited sediment that has been chemically altered and mixed with sand, organic materials, and other constituents. The ideal kaolin mineral structure has been altered by substitutions of other elements for the aluminum and silicon atoms in the kaolin crystals. The imbalance created by these substitutions produces a desirable “plasticity” characteristic when ball clay is used with water in the formation of ceramic articles. Coagulate, Flocculate For water purification or effluent treatment, fine solids suspended in water can be agglomerated and removed by coagulation and flocculation with agents such as lime, FeCl3 and polymers. Coat In the paper industry, lime is first transformed into a milk of lime (lime slurry) and then into PCC (precipitated calcium carbonate – CaCO3). PCC is used as a coating pigment to finish the paper surface. Coating Pigment Coating pigments for paper are usually supplied as slurry. They are a mixture of very bright, clean particles, such as pulverized limestone or kaolin. Compaction Compaction is a reduction in bulk volume of soil or aggregate by applying energy such as rolling and tamping. Concentration Concentration defines the quantity of an active substance in a mixture. Desulfurization Desulfurization is the removal of sulfur in the steel making process or in flue gas treatment. Dewatering Dewatering processes remove water. Disinfect Due to their high basicity values, Lhoist oxides and hydrated products are used in agricultural processes to destroy pathogens, bacteria and viruses in animal living spaces. In sludge treatment, lime prevents fermentation, limits odors and eliminates pathogens by raising the sludge pH to over 12 (stabilization & hygienisation). Dolime Dolime, CaO.MgO, is also called calcium magnesium oxide or burnt dolomite. Dolomite Dolomite, CaCO3.MgCO3, is also called calcium magnesium carbonate, dolomitic limestone, magnesian limestone or dolostone. Dolomitic Limestone Dolomitic limestone is metgrade limestone that contains varying proportions of magnesium carbonate. Dry In sludge treatment, lime absorbs water to form hydrated lime. This hydration generates heat and also contributes to water reduction. Lime treatment before solid-liquid separation also improves dewatering effectiveness, reducing sludge quantities. In civil engineering activities, lime is used to dry out wet soils. Effluent Effluent is the final discharge from processes. Electric Arc Furnace An electric arc furnace refines iron and scrap into steel using graphite electrodes. The electric arc travelling between the electrodes and the metallic charge creates intense heat which melts the charge. Alloying elements can be added during the process. Enrich In sludge treatment, Lhoist products enrich sludge with calcium and magnesium, which is desirable for agriculture purposes. Exothermic An exothermic reaction is a chemical reaction that generates heat. Fertilize In agricultural processes, calcium and magnesium are essential plants nutrients. Filler Fine ground limestone or dolomite stone can serve as a filler in asphalt, plastics, paint and paper. Fillers are substances added to a system or product to increase bulk, weight, viscosity, opacity, or strength and are often used to reduce cost. In civil engineering activities, limestone is used as a filler and hydrated lime is used as an asphalt additive to stiffen the asphalt mortar and increase the quality of asphalt mixtures used in road surface layers. Fine Lime Fine lime is one of the three main size categories of lime, generally below 2mm. Flocculant Flocculation is a process where a solute comes out of solution in the form of floc or flakes. Flocculation and sedimentation are widely employed in the purification of drinking water as well as in sewage treatment and treatment of other industrial wastewater streams. In civil engineering activities, with clayey soils, lime rapidly modifies soil structure, reducing plasticity. These two functionalities lead to improving the soil's bearing capacity for on-site transportation and compacting. Flux In the glass making processes, flux reduces the melting point of the silica sand (in complement to other flux agents such as Na2O), and this saves energy in industrial glass furnaces. In the steel making processes, limestone and lime reduce the melting point and increase fluidity of the slag. Flux is a type of chemical lime and is an agent that is normally a blended lime-based product utilizing fluidizers that will speed up the dissolution of the material so that it can collect impurities in the steel making process during gas stirring in the ladle or vessel. It is utilized to influence the reduction of active oxygen in slag and steel. GCC Ground Calcium Carbonate, GCC, is produced by crushing and grinding a carbonate rock, typically limestone, chalk or marble. Grain Lime Grain lime is one of the three main size categories of lime, generally from 2 to 12mm. Grinding Grinding is a process of size reduction, generally down to 2/3 mm. Gypsum Gypsum is the common name for the mineral consisting primarily of fully hydrated calcium sulfate, CaSO4 x 2H2O or calcium sulfate dihydrate. Gypsum occurs naturally in many areas and is produced by some wet Flue Gas Desulfurization (FGD) processes. Half-burnt Dolomite Half-burnt dolomite, CaCO3.MgO, is also called calcium magnesium carbonate oxide, dolomite calcined, half-calcined dolomite, calcium magnesium carbonate oxide or dolomitic lime. Half-hydrated Dolime Half-hydrated dolime, Ca(OH)2.MgO, is also called calcium magnesium (di)hydroxide oxide, half-slaked dolime, hydrated dolime or slaked dolime. Harden Hardening corresponds to an event where either via drying or a chemical reaction, a structure is strengthened. Examples include the drying of soils, binding of airlime with CO2 and the reaction of silica and calcium leading to hydrated calcium aluminates. Hardening is often also referred to as binding. Hydrated Dolime Ca(OH)2.Mg(OH)2, calcium and magnesium tetrahydroxide is obtained when dolime is mixed with water under pressure and temperature. Cf Type S Hydrated Lime Ca(OH)2, calcium hydroxide is obtained when calcium oxide is mixed, or 'slaked' with water. Hydrated lime is also called slaked lime. Cf Type N Hydration Hydration is the process used to transform an oxide (lime or dolime) into an hydroxide (hydrated lime or hydrated dolime). This process can be complete or partial. Hydraulic Lime Hydraulic lime is a chemically impure form of air lime with varying hydraulic properties. The hydraulic characteristics are generated by appreciable amounts of silica, alumina and usually some iron, chemically combined with lime, which will exhibit a hydraulic reaction when exposed to water. Hydraulic lime is usually used as binder for plaster and mortar. Industrial Minerals Industrial minerals are ‘naturally occuring chemical compounds’. Kaolin Kaolin is the generic name for the mineral kaolinite, a six-sided plate-like crystal formed of the oxides and hydroxyls of silicon and aluminum. When treated to remove any sand and organics, kaolin is desirable for use as a filler, a coating for brightness and as a source of aluminum in glass making and ceramics. Kaolin is also used as an additive in adhesives, paints and other products. Kilns Kilns employ industrial technologies used in the lime industry to remove CO2 from carbonates, to sinter dolomitic stones or to dry industrial minerals. Multiple types of technologies are used. Lake Liming Lake liming involves spreading pulverized limestone in lakes to combat acidification. Landfill A landfill is a disposal facility where waste is placed in or on land. Limestone Limestone is a sedimentary rock composed of the mineral calcite (calcium carbonate or CaCO3). Limestone can be processed into a crushed, granulated, ground or milled product. Loss on Ignition (LOI) LOI is the loss of weight under temperature effect and is used to determine bonding H2O and residual CO2 levels. Lump lime Lump lime is one of the three main size categories of lime, generally above 12mm. Magnesian Limestone Magnesian limestone contains appreciable amounts of magnesium, at least 90% calcite, and no more than 10% dolomite. Melting Point The melting point of a solid is the temperature at which it begins to liquefy. Milk of Lime Also known as lime slurry, milk of lime is a suspension of calcium hydroxide particles in water. These particles give the solution a milky appearance. Milling Milling is a process of size reduction, generally below 100µm. Mixed-Feed Shaft Kiln A mixed-feed shaft kiln is one of the numerous types of lime kiln technologies. In this kiln, the limestone (or dolomitic stone) is mixed with a charge of solid fuel, fed at the top of the kiln. Lime cooling air, blown from the baseline serves as combustion air. When the cooling air progressing upward meets the solid fuel (descending with the charge), it generates high temperature peaks. This allows the production of industrial lime that has a very low reactivity, possibly even dead-burned limestone or dolomite. On some other vertical kilns, fuel is injected through lateral lances inside the charge, directly in the calcination zone. Mortar Mortar is a mix of one or more inorganic or organic binders, aggregates, fillers, additives and/or admixtures. Neutralize In agricultural processes, Lhoist products reduce soils acidity to enhance the availability of plant nutrients, to boost biological activity and to improve the soil structure. In flue gas treatment, contaminant capture is an acid-base chemical neutralization, producing salts such as CaCl2, CaSO4 or CaF2. For water purification or effluent treatment, Lhoist products correct the acidity of water or effluents by adjusting their pH closer to neutrality (pH=7) or to the process pH target. Natural waters containing excessive CO2 (compared to equilibrium) are aggressive. This excessive CO2 is neutralized with the addition of carbonate-based products to recover water pH equilibrium. Nourish In agricultural processes, calcium and magnesium are essential elements in animal feed. Parallel Flow Regenerative Kiln (PFRK) The Parallel Flow Regenerative Kiln (PFRK) is one of the numerous types of lime kiln technologies, that is very energy efficient. This kiln technology is composed of 2 or 3 shafts interconnected by a crossover channel. The fuel is injected to the kiln via a series of lances that are plunged into the charge. This kiln operates in alternating modes: when a shaft is in burning mode, it receives energy from the tips of the lances while the other shaft is in preheating mode, where the flue gas transfers its energy to the limestone. Approximately every 12 minutes, the cycle is reversed. The temperature of the limestone increases as it moves down through the kiln until it reaches the level of the lance tip. This is followed by a calcination phase at an intermediate temperature (less than 1100°C) which ensures that reactive limes are produced. PCC Precipitated Calcium Carbonate, PCC, is manufactured via a series of controlled chemical reactions. Quicklime is usually mixed with water to form a slurry to which carbon dioxide is added. The resulting reaction produces a very fine precipitated calcium carbonate (CaCO3). This filler is used in paper production to enhance the paper's whiteness, opacity and texture. Pebble Refer to lump lime. Pozzolanic The term pozzolanic is used to describe a reaction of reactive silica- and alumina-containing materials (puzzolanic materials) consuming calcium hydroxide, forming hydrated calcium silicates to a hard mass. Precipitate For water purification or effluent treatment, heavy metals are less soluble in water in specific pH ranges, where they form precipitates. Other ions such as sulfates, phosphates or fluorides can also be eliminated from water by pH adjustment. Protect Dolime is a very stable refractory material due to its high melting point (2400°C). Consequently, dolime offers good resistance to very high temperatures. Additionally, with highly reduced porosity, dead-burned products also provide better resistance to: • Hydration (before use) • Liquid phases infiltration (in customer processes) In steel making processes, lime, especially dolime, prolongs the life of the refractory lining. Purify In steel making processes, lime and dolime remove impurities from iron ore, mainly silica and aluminia, by reacting with them to form a molten slag. They also remove minor impurities such as sulfur (S) and phosphorus (P). Putty Putty is a mixture of lime (calcium hydroxide) in water which is used for the production of lime plasters, renders and mortars. PV Pore Volume, PV (measured in cm³/g), is the direct measure of the accessibility of SSA. Quicklime Quicklime, CaO (calcium oxide), is produced by the calcination of limestone, also called hical lime. Reactivity Reactivity is a measure of the rate at which lime or dolime reacts with water. 'Moderate', 'medium', and 'low' reactivity are used as broad classifications for quicklimes. Refining Refining is the removal of impurities in general, and in the lime manufacturing process the term is also used for milling, hydration or milk of lime (lime slurry) production. Regenerate In the paper industry, lime is used in the chemical pulp-making process to recover and regenerate Na(OH), which is a reagent used to extract cellulose fibers from wood. Remineralize In water purification or effluent treatment, drinking waters lacking minerals (e.g. dissolved Ca++ and HCO3-) are remineralized through the addition of lime. Depending on the water/CO2 equilibrium, CO2 will be added simultaneous (bubbling). This remineralization generates dissolved calcium bi-carbonates Ca(HCO3)2 that stabilize the water at its equilibrium pH. Rendering Mortar Rendering mortars are durable coatings of lime and aggregate which provide a protective covering for building walls. Rise In the building industry, rise describes the volume increase during the rising process that is used to produce aerated autoclaved concrete. Rotary Kilns The Rotary Kiln (RK) is one of numerous types of lime kiln technologies. The rotary kiln is a long inclined tube, about one hundred meters in length, fed with stone sizes ranging from 50mm down to less than 3mm. The rotation and the inclination of the tube force the limestone to roll from the top to the bottom. The charge occupies only 10% of the cross-sectional area of the shell; the remaining area is occupied by the ascending gas flow, sucked by an exhaust fan. Fuels are injected in a main burner, positioned down the tube just before the cooler. These kilns can generate various flame profiles and are used to produce high quality lime with low CO2 residual, controlled reactivity and low sulphur content. Sandlime Bricks Sandlime bricks are calcium silicate bricks produced by autoclaving a mixture of sand and lime. Slag Slag is a by-product in iron making and steel making. Slag consists of oxides from fluxing agents, raw material impurities and undesired elements which are oxidized during the process. Slaked Lime Slaked lime is also known as hydrated lime. Sludge Sludge is any solid, semisolid or liquid waste generated from a municipal, commercial or industrial wastewater treatment plant, water supply treatment plant or air pollution control facility (wet scrubbers). It is also any other such waste that has similar characteristics. Slurry Slurry is particles in a water suspension. Soft Burned Lime Soft burned lime is lime that is highly reactive. Soften In water purification or effluent treatment, hard water contains high levels of soluble bicarbonates HCO3-. Softening via lime addition involves the precipitation of these bicarbonates in the form of insoluble carbonates CaCO3 or MgCO3. Solubility The solubility (S) of a compound is the maximum quantity of that compound that can be dissolved in one liter of water (measured in mg/L). Sorbent In some combustion systems, sorbent is the term applied to chemical compounds that are added to the gas side of a steam generator to reduce emissions. For example, limestone is used in fluidized-bed steam generators to reduce sulphur dioxide emissions. SSA Specific Surface Area is a measure of total accessible surface (m²/g). In flue gas treatment, SSA characterises the contact surface of hydrated lime with gases. Stabilize In civil engineering activities, lime reacts with pozzolanic materials to produce binders that progressively harden in the presence of water. This functionality is used to stabilize clayey materials used in embankments and pavement layers. In glass processes, CaO and MgO block the crystallization process, stabilizing the amorphous and transparent glass. Structure In building, limestone aggregates form the skeleton of concrete structures. In civil engineering activities, limestone aggregates are used in capping and pavement layers to distribute loads, thus reducing road structure failures due to heavy traffic. This structural functionality can also be obtained with lime treated soils. In agricultural processes, liming improves the soil's physical structure, improving water and air penetration. In sludge treatment, lime improves sludge structure in a granular form, resulting in easier handling and treatment (piling, storage, transport). Stucco Stucco is a form of plaster for coating walls. Stucco is also referred to as render. Tadelakt Tadelakt is a bright, nearly waterproof lime plaster which can be used both on the inside and outside of buildings. Type N Hydrated lime with an average/Normal behavior toward the Emley test, which combines water retention and shear force. Type S Hydrated lime with a guaranteed behavior towards the Emley test, which combines a high water retention and shear force. Special hydrated lime is an ASTM designation to distinguish a structural hydrated from a normal hydrated lime. Whiten In the paper industry, lime is first transformed into a milk of lime (slurry) and then into PCC (precipitated calcium carbonate – CaCO3). PCC is added as a filler to cellulosic fibers, in order to increase paper brightness, whiteness, opacity and bulk. Sources : Lhoist Group, EULA Glossary Lhoist - Minerals and lime producer HOME ABOUT US SUSTAINABILITY MARKETS & SOLUTIONS INNOVATION PEOPLE AND CAREERS CONTACT ALL ABOUT LIME & MINERALS DOWNLOAD CENTER MEDIA GALLERY Copyright Lhoist Disclaimer Privacy Policy