A glance on cement appearance history
Archeological discoveries and researches performed on remaining parts of ancient buildings and of historians issues show that Romans were the first people found out the quality and application of cement and its concepts regarding setting and hardening. Since 2600 BC to the mid-eighteenth century, in addition to clay and gypsum, another cohesive material called baked lime was produced synthetically which was obtained by baking limestone called quicklime (cao) and then it could be changed to slake lime by sprinkling water which subsequently it turned into limestone powder. Lime mortar which was mentioned above was used exclusively to construct brick walls, temples and the like, but it was not used in construction of channels because it could not become hard in the water. Therefore it could not satisfy needs of marine construction such as bridges, dams, jetties and so forth. After centuries Romans were achieve a great discovery and added a substance to lime powder called pozzolan which was added to quicklime powder. They added water and made a mortar which could stay hard after setting under water and in the air. After this great discovery, the benefits of the mixture containing baked lime and clay were realized which is considered as the first step to make cement.
In that age, a product obtained via combination of pozzolan and lime was named CAEMENTE, derived from the Greek word “CAEDER “(meaning cutting, to be cut and break) which was referred to the broken stones (rubble). CAEMENTE, up to the mid-eighteenth century was applied for those materials used in mixture with an object and therefore led to increase the object’s hardness.
Cement with its contemporary meaning was first used by Parker (PARKER) Englishman in 1796. The word “cement” in German, English and French are used to refer to all the materials(except asphalt)with adhesion properties which are used in buildings and roads. In Germany, Cement was standardized for the first time in 1878 with the symbol DIN 1164.
Toward unknown borders
The year 1756 AD is considered as the beginning of a new chapter in the history of Portland cement. Because in this year, an Englishman, JOHN SMAETONE, who lived between 1792-1724 discovered a great and valuable point. He needed a water resistant mortar for reconstruction of the lighthouse building (seaside lights) to guide ships in the PLYMOUTH EDDYSONE LEUCHTTURM port. Finally after great efforts and tests and through baking limestone (GLAMORGAN) for the first time he discovered a special quality of hydraulic lime mortar by which he became aware of a very significant phenomenon. This means that chemical analysis of limestone indicated the existence of clay in the mixture. But this great discovery was not welcomed until 1796 when an Englishman named JAMES PARKER by baking London Marley stones obtained a product called ROMANCEMENT.
Between 1819-1815 the two great French scientists called Wicca VICAT (1861-1786) and another German scientist named J. FJOHN (1847e-1782) reviewed separately this research and concluded that baking the mixture of lime stones and clay to the amount of 25 to 30 , will result the most appropriate hydraulic product. Aspdin (JOSET ASPDIN), an English architect, in 1824 made an artificial mixture from limestone and clay and then gridded it in a wet method to be changed to slurry and well homogenized. Then it was heated in a temperature lower than melting temperature. The obtained product is called Portland cement due to its similarity with a yellow stone called PORTLANDSTONE which was extracted in the Portland island of England. Aspdin – W in the year 1843, the son of Joseph Aspdin, began to produce Portland cement in the newly established factory, and when was making British Parliament building found out that the cement was much better than Roman cement. Further investigations made clear that the main reason of this excellence is that the Portland cement mix has been heated to the sweating point (sintering).
Chemistry at the service of Cement:
Scientists like Mykalys W. MICHAELS (1911-1840), Loshatlyih lechatelier (1936-1850), Hans Kohl HANS KUEHL (1969-1879) and others went to look an unknown world and performed scientific researches in the field of chemistry of cement. German scientist (ELAGEN) in 1862 discovered the latent hydraulic property (LATENTHYDRAULIC) of furnace slag and finally in 19014 discovered sulfate slag cement where the sulfate had the role of slag activator. High aluminum cement or aluminum cement called TONERDESCHMELZZEMENT) melted alumin cement was discovered by French chemist called JULE BIED In 1908 and was produced for the first time during the first International War I (1918-1914)
Completion process of cement burning technology:
Rotary kiln entered cement burning technology by the Englishman RANSOME for the first time in 1885 which its next stage of evolution was a turning point in the cement industry and then was completed by an American engineer. The first rotary kiln in Germany was set up by V. FORELL in 1897 in LOLLAR located on GIESSEN district based on Ransome invention . The Length of this kiln was 16 meters with a daily capacity of 30tons. In Germany, Portland cement was produced in BUXTEHUDE city for the first time in 1850, based on the method which was usual in England. Founder of Portland cement in Germany was a person named BEEIBTREU(1881-1824) constructed the two cement factory, one in TUELCHOW (1855) STETTIN near OBERKASSEL and the other near Bonn (1858).
At the end of the nineteenth century, Rotary kiln entered the cement baking technology with slurry method. In this method, at first, raw materials become slurry in a basin in order to be highly homogeneous. Pioneers of slurry System are the companies polysius, Krupp, MIAG, FELLNER and ZIEGLLER from Germany and Smith L.F from Denmark. The next step occurred in 1929 and that was the innovation of the system named (LEPPOL LELLEP POLYSIUS) which is known in America as (ALLIS-CHALMERLELEPP) (ACL).
(LELEPP is the name of the above mentioned system inventor). This is considered as another major advance in cement technology, because the system is equipped with mesh pre heaters which are considered as special properties of this system. since it was economical and from fuel consumption point of view had more advantages in compare with the other systems. years later, for the first time, the kiln equipped with a cyclone pre heater was entered the market of the cement industry by KLOCKNER-HUMBOLDT-DEUTZ which is the most common dry system in cement technology world now.
In recent years in order to develop the kiln tonnage a kind of secondary or auxiliary pre heater has been developed so that a significant proportion of the materials become calcinated before entering the kiln and therefore this causes an increase in tonnage.
Cement making industry in Iran:
The first stage of cement application in Iran entered by the foreigners for using their facilities in public places such as churches, embassies, commercial ports and so forth. But social revolutions and industrialization movements of the country increased the necessity of supplying cement. From the time of the construction of large buildings such as the state railways, bridges and tunnels and stations, cement began its role as an import item in the country whereas the mentioned goods were not produced So each year some of the exchanges Log out of the country while the raw material for cement production was available in the country in a great amount.
Therefore the government decided to purchase necessary machineries to build a small factory with one hundred tons of cement production capacity. In 1310 earnings of sugar and sugar productions which were allocated for railway construction, actually allocated to the establishment of cement factory and the action was performed in February 1310 in 7 km far from south of Tehran near the Bibi Shahrbano and sorsore mountains and ended in December 1312. Machineries of FL Smith factory (FL SMIDT), Danish factory, were purchased and installed in late Year 1312 and started the operation. But whereas consumption of cement is increasing more and more and the products of above mentioned factories do not satisfy internal demands, therefore construction of new plants with capacity of 200 tons of cement in south of the previous plant building established in .
Construction of this building started at 1315 and ended in early 1316. New machineries purchased from German factory (Polysius) and then installed. People welcomed produced cements and the government decided to purchase and install three hundred ton kilns and also purchased another plant in the vicinity of Polysius and all necessary steps performed to purchase the said machinery and construction was started, but because of the second World War and lack of connection with Germany, the projects was stopped. Finally in 1330, based on the building materials co. suggestion and MPO approval to set up the plant whose construction progress was about 57 percent during 1318 to 1320, the action was taken and, machineries were purchased from German company and installed and became in operation in second half of 1334. In 1317, making a hundred-ton plant in Lorestan province and three hundred-ton plant in Tabriz, Mashhad and Shiraz were planned by the ministry of Industries and Mines which remained suspended due to the second international war.
History of cement plants – Publication of Abyek cement training center
(Mr. Seyed Mohammad Ali Akhbari )