Patent ID: 7182808

Claim:
An accelerator composition adapted to be used with sprayed cementitious compositions, comprising an aqueous solution or dispersion of a blend of Components 1–4: Component 1—aluminium sulphate Component 2—at least one of an alkanolamine, an alkylene diamine or alkylene triamine Component 3—hydrofluoric acid Component 4—at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, magnesium carbonate, sodium sulphate, potassium sulphate, magnesium sulphate or lithium sulphate; Optionally with at least one of Components 5–7: Component 5—at least one of C 1 –C 10 aliphatic mono-carboxylic acids, C 1 –C 10 aliphatic dicarboxylic acids or their metal salts; Component 6—aluminium hydroxide; or Component 7—at least one of phosphoric acid or phosphorous acid; the components being present in the following proportions (active ingredients by weight of total accelerator composition) and having an alkali metal equivalent content greater than 1% Na 2 O equivalent; Component 1—from 30% to 60%, calculated on the basis of Al 2 (SO 4 ) 3 .14.3H 2 O; Component 2—from 0.1% to 15% Component 3—from 0.2% to 8% Component 4—greater than 0% to 15% Component 5—up to 15% Component 6—up to 15% Component 7—up to 5%.