| abstract |
A method for controlling colloidal/amorphous silica scale deposition in an aqueous system is described, which comprises adding to the aqueous system an effective amount of a synergistic combination comprising: A) 10% to 90% by weight of at least one carboxylate polymer comprising units derived from one or more carboxylate monomers; and B) 90% to 10% by weight of at least one chelating agent, based on the total weight of said synergistic combination. The carboxylate polymer may be a homopolymer of (meth)acrylic acid, maleic acid, itaconic acid, or their salts, or a copolymer of one or more monomers selected from meth)acrylic acid, maleic acid, itaconic acid, and their salts and, optionally, one or more sulfonic-free ethylenically unsaturated monomers. The chelating agent may be one or more of: methylamine, ethanolamine methylethanolamine (MEA), ethylenediamine (EDA), diethylenetriamine (DETA), ethylenediamine tetraacetic acid (EDTA), ethylenediamine disuccinic acid (EDDS), iminodiaacetic acid (IDA), tetrasodium ethylene diaminetetraacetic acid, and derivatives thereof, among others. |