Patent ID: 7947334

Claim:
A method of preparing an accelerator for sprayed cementitious compositions, consisting essentially of the steps of (i) dissolving aluminium sulphate and aluminium hydroxide in water, which contains at least one amine dissolved therein, to give a clear solution; (ii) adding a stabiliser; and (iii) optionally adding at least one defoaming agent; the proportions of ingredients present being such that the final product contains from about 3% to about 12% by weight of aluminium sulphate (measured as Al 2 O 3 ), from greater than 0% up to about 30% by weight of amorphous aluminium hydroxide, from greater than 0% up to about 15% by weight amine, from 0% up to about 3% solids by weight of the whole composition defoaming agent and from 0.1 mol/kg up to about 1.5 mol/kg stabiliser comprising glycolic acid.