Rotary kiln (furnace) for manufacturing Portland cement clinker.Inset view inside the kiln.
Clinker & Gypsum Clinker GypsumPortland cement clinker is formed by burning calcium and siliceous rawmaterials in a kiln. This particular clinker is about 20 mm (3¼ - 4 in.) indiameter.Gypsum, a source of sulfate, is interground with Portland clinker to formPortland cement. It helps control setting, drying shrinkage properties, andstrength development.
Hydraulic Portland Cement A cement that sets and hardens by chemical interaction with water and capable of doing so underwater A cement that contains only hydraulic Portland clinker, 5% limestone and gypsum A cement that has prescriptive requirements
Blended Hydraulic Cement A cement that consists of two or more inorganic constituents, one which is not a Portland cement clinker or a cement Ingredients are proportioned and prescribed with some performance attributes
Performance Cement A Blended Hydraulic Cement A Cement that consists of two or more inorganic constituents A cement that performance criteria alone governs the product constituents
Portland Cement Shipments by Type Type V White TYPE III3% 0% Blended 3% 1% Types I & II 93%
Slag - Manufacture Iron Blast FurnaceIron Ore Limestone/CoalFusion at1400 to 1600 C Slag Pig Iron
Slag - Manufacture Molten blast furnace slag is tapped from the blast furnace, moved through a hot runner on the blast-furnace work floor. Dropped in a “blow” box to a jet-process granulator. GGBF is glassy - with the right chemistry and morphology to form hydraulic cement when finely ground.
Slag Cement Slag Cement, also known as ground granulated blast furnace slag, Ggbfs Slag Cement is a ground glassy granulated material formed when molten blast-furnace slag is rapidly chilled as by immersion in water
What is Fly Ash?• Finely divided material that is removed from the exhaust gas of a high temperature combustion process of coal burning power plants.
Source of Coal Fly Ash• Coal Source and Ash Composition• Stack Gases Contain Liquefied Minerals• Cooling of Gases form Spherical Particles• Electrostatic or Bag-House Precipitators
Silica Production & Silica FumeSilica fume is a byproductof producing silicon metalor ferrosilicon alloys in anelectric-arc furnace.The raw materials goinginto the furnace, theelectric-arc furnace (2000C), and the smokecollection system areshown.
What is Silica Fume? Very fine non-crystalline silica produced in electric arc furnaces as a byproduct of the production of elemental silicon ….. -- ACI 116R
What is Silica Fume?• Cement grains (left) and silica fume particles (right) at the same magnification.• The longer white bar in the silica fume side is 1 µm long.• ACI 234R-96, Guide to the Use of Silica Fume in Concrete.
Historical Prospective Ancient Egyptians used calcined gypsum Greeks and Romans used calcined limestone Romans combine volcanic ash and lime (Pozzuoli, near Vesuvius)
Roman Structures Coliseum in Rome Pantheon in Rome
Beginning of the Industry • John Smeaton, Commissioned in 1759 to rebuild Eddystone Lighthouse • Mixing of Pozzolana with limestoneIsle of Portland quarry stone (after which Portland cement was named)next to a cylinder of modern concrete.
Natural Cement Stronger than a hydraulic lime Manufactured in Rosendale, New York (1800’s) Used to build Erie Canal, 1818
Hydraulic Cement Joseph Aspdin, patented “Portland Cement”, 1824 Portland cement, resemblance to color of natural limestone Limestone quarried: Isle of Portland off English Channel
Portland Cement Exports to North America, 1865 Shipments to United States, 1868 First Portland Cement produced in US, Coplay, Pennsylvania 1871
IntroductionPlease return to Blackboard and watch thefollowing video: Video 1: Chemical Compounds in Portland Cement