Cement clinker

– Composition and preparation:
– Portland clinker consists of four minerals: alite, belite, tricalcium aluminate, and calcium aluminoferrite.
– Raw materials for clinker include limestone mixed with clay or silicon dioxide.
– Second raw materials depend on limestone purity and can include clay, shale, sand, iron ore, bauxite, fly ash, and slag.
– Production involves heating raw materials in a rotary kiln at high temperature.
– Special cements require limiting tricalcium aluminate formation.

– Uses:
– Portland cement clinker is ground to a fine powder and used as a binder in various cement products.
– Addition of gypsum is necessary to prevent flash setting of tricalcium aluminate.
– Clinker is used in different types of cement like Ordinary Portland Cement (OPC) and pozzolanic cements.
– Clinker is an ingredient in artificial rock called pulhamite for landscaping.
– Clinker can be stored for months without quality loss and is traded internationally.

– Clinker grinding aids:
– Gypsum is added to prevent flash setting and aid in grinding by preventing agglomeration.
– Organic compounds like triethanolamine are used as grinding aids.
– Other additives such as ethylene glycol, oleic acid, and dodecyl-benzene sulfonate are sometimes used.

– Clinker minerals hydration:
– Clinker minerals react with water to form hydrates and set as concrete.
– Calcium silicate hydrates are the main glue components in concrete.
– Initial setting occurs in the first 28 days, and hydration requires water for hardening.
– Desiccation must be prevented to avoid cracks in young concrete.
– Curing compounds can be used to create a water-impermeable coating on concrete surfaces.

– Contribution to global warming:
– Cement production accounted for about 8% of global carbon emissions in 2018.
– Most emissions are generated during the clinker manufacturing process.https://en.wikipedia.org/wiki/Clinker_(cement)