Method for making silicate/aluminate sorbent
AssigneeUniversity of Greenwich
InventorsColin Douglas Hills, Cecilia Louise MacLeod
Life of this patent
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Abstract
Silicate-based substantially non-hydrated sorbent material comprising predominantly calcium silicate and/or calcium alumino-silicate has an atomic framework at least partially de-calcified in that a plurality of calcium atom sites in atomic framework are vacant. The activated material can be used as industrially useful sorbents for contaminant species such as metal ions, in the solidification of waste, in similar applications, and in the absorption of carbon dioxide which might otherwise be exhausted to atmosphere. The material has a further use as a precipitant of certain ionic species e.g. lead, leading to its removal from aqueous solution by precipitation.
Claims9
A method of making a sorbent material which comprises:
- providing a calcium silicate-based clinker or glassy residue including calcium silicate, dicalcium silicate or tricalcium silicate phases:
- grinding or pulverising said clinker or glassy residue;
- adding water to the ground or crushed clinker or glassy residue at a water/solid weight ratio of up to 0.4:1 to form a wet mixture;
- and
- exposing the wet mixture to a medium which is predominantly carbon dioxide, whereby calcium atoms in the atomic framework of the calcium silicate, dicalcium silicate or tricalcium silicate phases are carbonated thereby providing an unhydrated sorbent material in which said atomic framework of the material is at least partially decalcified by carbonation resulting in vacancy of a plurality of calcium atom sites in said framework.
A method of making a sorbent material which comprises:
- providing a calcium silicate-based clinker or glassy residue including calcium silicate, dicalcium silicate or tricalcium silicate phases:
- grinding or pulverising said clinker or glassy residue;
- adding water to the ground or crushed clinker or glassy residue at a water/solid weight ratio of up to 0.4:1 to form a wet mixture;
- and
- exposing the wet mixture to a medium which is a waste gas stream containing carbon dioxide and one or more waste species, whereby calcium atoms in the atomic framework of calcium silicate, dicalcium silicate or tricalcium silicate phases of the calcium silicate-based material are carbonated thereby providing an unhydrated sorbent material in which said atomic framework of the material is at least partially decalcified by carbonation resulting in vacancy of a plurality of calcium atom sites in said framework.
Dependencies are inferred from the claim text.