A zero-waste process for the management of MSWI fly ashes: production of ordinary Portland cement.

Municipal solid waste incineration (MSWI) fly ashes are hazardous waste since they contain organic pollutants, heavy metals and an important amount of various soluble salts. However their chemical composition is interesting for their valorization in cement production. The objective of this paper is to assess the possibility of MSWI fly ashes reuse as cement raw meal, after pre-treatment, at a laboratory scale.

Identification of solvated species present in concentrated and dilute sodium silicate solutions by combined 29Si NMR and SAXS studies.

Both concentrated and diluted sodium silicate solutions have been investigated by combining (29)Si NMR spectroscopy and SAXS experiments. The chemical nature of the entities responsible for the high siliceous species solubility observed in such alkaline concentrated sodium silicate solutions and their evolution according to dilution have been identified. For the most concentrated solution ([Si]=7 mol/l; pH=11.