Cement News tagged under: chemistry

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Effects of age and type

21 September 2015, Published under Cement News

Limestone, a key element in the cement raw material mix, does not occur as a homogenous body of rock, but can vary widely in age and type across the world. These differences can have significant effects on cement production. Arthur Harrisson considers the effects of limestone age and type on the rock’s properties such as hardness, chemistry, grindability and burnability in various stages of the cement production process. Limestone deposits used for cement manufacture vary widely in ag...

Dealing with natural variation

26 January 2015, Published under Cement News

The variability in deposition environment and the depth of its location in the quarry mean that limestones show significant variation at different places. For the cement producers, this presents challenges to obtain a uniform raw material supply. Stratigraphical variation in the quarry presents challenges to obtain a uniform raw material supply Cement clinker is made primarily from naturally-occurring raw materials, the highest proportion of which is limestone. Most limestones w...

The importance of raw materials

17 February 2014, Published under Cement News

Proper analysis and identification of raw materials are essential to achieving the best clinker in the kiln. All clinkers will have a small degree of unwanted elements, but much can be learnt about reaching the desired levels of strength, setting time and crystal content by understanding what makes good- and poor-quality clinker. For a new cement plant the main raw material selection is generally the first and most important phase of development. If the everyday supply of limestone is not...

Kiln feed and clinker quality

16 December 2013, Published under Cement News

Commissioning a new cement plant generally centres around the performance in terms of tonnes per day, kWh/t, or other operational matters. It is easy to lose sight of the need to achieve the required quality while fulfilling these other requirements. The following article describes a case study of quality issues and the means of improvement during the commissioning of a 4000tpd precalciner kiln. Coarse (brown) alite crystals, coarse prismatic C3A and degraded alite indicating poor-qua...