Method For Treating Clay And Clay-Bearing Aggregates And Compositions Therefor

摘要

The present invention provides compositions and methods involving the use of a carboxylate graft polymer having high molecular weight and low ratio of acid-to-polyoxyalkylene groups. Such clay-mitigation is particularly useful for treating clay and clay-bearing aggregates, particularly those aggregates used for construction purposes. The present invention minimizes the need to wash the aggregates, thus preserving fine aggregates (“fines”) content in construction materials, and thereby beneficiating the performance and/or properties of construction materials containing the clay-bearing aggregates.

主权项

1. A carboxylate graft polymer composition for treating clay or clay-bearing aggregates, comprising:
(A) a first component represented by the following structure:wherein R1, R2, and R3 each independently represent hydrogen, C1-C3 alkyl, —COOH, —CH2COOH, or mixtures thereof; X represents hydrogen or an alkali metal; and
(B) a second component represented by the following structure:wherein R4, R5, R6, R7, and R8 each independently represent hydrogen, C1-C3 alkyl, —COOH, or mixtures thereof; Y represents —O—, —COO—, —OOC—, —COHN—, or —NHCO—; Z represents (CH2)n wherein “n” represents a whole number of 0 to 6; and “m” represents an integer of 25 to 200;
(C) optionally a third component comprising a repeating unit of polymerized (meth)acrylamide, N-alkyl (meth)acrylamide, N,N-dialkyl (meth)acrylamide, 3-acrylamido-2-methylpropane sulfonic acid or its salts, and styrene sulfonic acid or its salt, or mixtures thereof; and wherein the molar ratio of said first component A to said second component B is in the range of 50:100 to 100:40 and the weight-average molecular weight of the carboxylate graft polymer is in the range of 22,000 to 250,000; and wherein, if the molar ratio of said first component A to said second component B is greater than 100:55, then the weight-average molecular weight of the carboxylate graft polymer is in the range of 70,000 to 250,000.