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The method of making cement from limestone (CaCO 3) and low-silica bauxite (Al 2 O 3) was patented in France in 1908 by Bied of the Pavin de Lafarge Company. The initial development was as a result of the search for a cement offering sulfate resistance. The cement was known as "Ciment fondu" and "Ciment électro-fondu" in French. [2] [3]
Calcium oxide is a crucial ingredient in modern cement, and is also used as a chemical flux in smelting. Industrial calcination generally emits carbon dioxide (CO 2). A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing (550–1150 °C, or 1000–2100 °F) within a controlled ...
Equipment for pyroprocessing includes kilns, electric arc furnaces and reverberatory furnaces. Cement manufacturing is a very common example of pyroprocessing. The raw material mix is fed to a kiln where pyroprocessing takes place. As with most industries, pyroprocessing is the most energy-intensive part of the industrial process.
These HPCs will be high strength, highly durable, and exhibiting greater strength-development in contrast to HPCs made from untreated Portland cement. [24] Treating Portland cement with the EMC Activation process may increase the strength development by nearly 50% and also significantly improve the durability, as measured according to generally ...
Ground granulated blast furnace slag is a latent hydraulic binder forming calcium silicate hydrates (C-S-H) after contact with water. It is a strength-enhancing compound improving the durability of concrete. It is a component of metallurgic cement (CEM III in the European norm EN 197).
Portland cement clinker was first made (in 1825) in a modified form of the traditional static lime kiln. [2] [3] [4] The basic, egg-cup shaped lime kiln was provided with a conical or beehive shaped extension to increase draught and thus obtain the higher temperature needed to make cement clinker.
The cement industry uses the LOI method by heating a cement sample to 900-1000 °C until the mass of the sample stabilizes. Once the mass stabilizes, the mass loss due to LOI is determined. This is usually done to assess the high water content in the cement or carbonation, as these factors diminish the quality of cement. [10]
Post weld heat treatment (PWHT) is a controlled process in which a material that has been welded is reheated to a temperature below its lower critical transformation temperature, and then it is held at that temperature for a specified amount of time. [1]