Cement News tagged under: belite
Producing boron cement24 August 2021, Published under Cement NewsThe creation of low-energy belite clinker is a specific area of research that aims to reduce CO 2 emissions from the cement manufacturing process. Boron minerals, of which Turkey has 73 per cent of the world’s reserves, are a possible raw material that can be used in the production of belite cements. TÜRKÇIMENTO, the Turkish cement manufacturers’ association has carried out a study into the use of colomonite boron ores to determine their suitability for the production of boron cement. By Se... |
Belite size distribution13 April 2021, Published under Cement NewsBelite size is affected by several factors ranging from raw materials, the length of the burning zone, the fuels used in the production process as well as the conditions in the cooling zone. Figure 1: example of belite crystal size distribution The sizes of belite crystals in Portland cement clinker depend on a number of factors that relate to the raw materials, burning zone length, fuels used and combustion efficiency. Raw materials The relative proportions of alite and ... |
Process, mineralogy and cement quality08 December 2020, Published under Cement NewsThis month Arthur Harrisson looks at the relationship between temperature differences in the clinker manufacturing process, the composition of clinker produced and the quality of the final cement. Figure 1: variation of iron oxide and alumina in alite with clinker exit temperatures In a project to explore the influence of different temperature profiles on clinker characteristics, a range of commonly available measurements relating to the clinker manufacturing process were matche... |
Belite-based low-carbon clinker cements10 March 2020, Published under Cement NewsWhile Portland cement is expected to remain the most-used cement type in concrete production, alternative cements are gaining importance. This has seen the continued development of alternative clinkers, such as belite-based low-carbon clinkers with a belite content of more than 40 per cent, in China over the last two decades. By Tongbo Sui, Sinoma Research Institute, China, Hao Sui, Monash University, Australia, and Bin Wang, Sinoma Research Institute, China. Clinker used in the produ... |
Belite in Portland clinker22 July 2019, Published under Cement NewsWhile belite is often represented as a pure dicalcium silicate, in practice the phase contains a range of impurities. Arthur Harrisson highlights the differences in belite composition and examines the causes of such impurities. Type I belite crystals with dark laminations containing exsolved matter The belite phase in Portland cement clinker is often characterised as dicalcium silicate or C 2 S, implying a lime-to-silica ratio of 2:1. The ratio refers to the number of CaO units ... |
Belite appearance in clinkers11 April 2019, Published under Cement NewsThis month Arthur Harrisson looks at the second-most abundant constituent of cement – belite – and its appearance in clinkers. Figure 1: Type I belite with multiple sets of parallel laminations. The blue crystals are alite Of the four main constituents of cement clinker, the tricalcium silicate known as alite is the most abundant and is the one that is conventionally maximised to react with water to produce calcium silicate hydrate, the material required to achieve strength in a... |
Crystal clusters in clinker13 December 2017, Published under Cement NewsWith increasing use of alternative fuels, short homogenisation times in precalciner kiln systems and the requirement for high alite cement, the presence of crystal clusters is not expected to be a thing of the past. While the impact of crystal clusters in clinker on quality is not always clear, some effects can be seen. Figure 1: brown and lighter blue belite crystals surrounding liquid phase Cement clinker for general-purpose Portland cement is composed essentially of four... |
C2S solid solution reactivity in high-belite cement28 November 2017, Published under Cement NewsThe key cause of the high energy intensity in the cement production process is the high heat required to form alite, the main constituent of Portland cement. One option is to lower the alite content, which leads to a higher share of belite. However, such high-belite cement often has a lower early strength, impacting on the quality of the final product. To address this issue, achieving a suitable control of belite reactivity is essential. By Dr Eng Daisuke Kurokawa and Shun Niijima, Taiheiyo... |
Crystal inclusions in Portland cement clinker10 August 2016, Published under Cement NewsThe nature of inclusions in clinker crystals provides clues about the burning environment and are therefore important indicators of clinker quality. Figure 1: blue belite inclusions in alite crystals Of the four main crystalline compounds that are found in Portland cement clinker, two are produced as solids and two are present in the burning zone of the cement kiln as a liquid, which then crystallises on cooling. Microscopic examination of clinker has been employed as a quali... |
How much alite?18 May 2015, Published under Cement NewsThe content of alite and other cement phases such as belite, aluminate and ferrite can have significant effects on the strength of the final mortar. This article looks at the correlation between alite and other cement phases on the 28-day strength of cement as well as some of the production conditions required to produce high-quality cement in these circumstances. Figure 1: quantity of alite and 28-day strength from seven cement plants It is well known that the four main phases ... |