A slurry comprising: a mixture of water; a hydraulic component comprising at least 80% calcium sulfate hemihydrate by weight based on the dry weight of the hydraulic component; and a linear polycarboxylate anionic dispersant consisting essentially of a first monomeric repeating unit A and a second monomeric repeating unit B, and an absence of polyvinyl acetate monomeric units; wherein the first repeating unit A is at least one carboxylic acid functional group containing olefinic moiety of formula I: wherein R is selected from the group consisting of -CH 3, and -CH 2 -C -OH, or a Na, K, or NH 4 + salt thereof; and wherein the second monomeric repeating unit B is at least one vinyl sulfonate according to formula II: wherein X is NH or O; R 1 is H or -CH 3; R 2 is a linear or branched alkylene group having the formula -(C n H 2n)-, wherein n=2 to 6; M= H, Na, K, or NH 4 +; wherein the molar ratio of the first repeating unit A to the second repeating unit B is A is between 1:9 and 9:1; wherein the weight average molecular weight of the linear polycarboxylate anionic dispersant is 3000 to 100000 Daltons; wherein the slurry has a water to calcium sulfate hemihydrate weight ratio of 0.1-1.5:1. a mixture of water; a hydraulic component comprising at least 80% calcium sulfate hemihydrate by weight based on the dry weight of the hydraulic component; and a linear polycarboxylate anionic dispersant consisting essentially of a first monomeric repeating unit A and a second monomeric repeating unit B, and an absence of polyvinyl acetate monomeric units; wherein the first repeating unit A is at least one carboxylic acid functional group containing olefinic moiety of formula I: wherein R is selected from the group consisting of -CH 3, and -CH 2 -C -OH, or a Na, K, or NH 4 + salt thereof; and wherein the second monomeric repeating unit B is at least one vinyl sulfonate according to formula II: wherein X is NH or O; R 1 is H or -CH 3; R 2 is a linear or branched alkylene group having the formula -(C n H 2n)-, wherein n=2 to 6; M= H, Na, K, or NH 4 +; wherein the molar ratio of the first repeating unit A to the second repeating unit B is A is between 1:9 and 9:1; wherein the weight average molecular weight of the linear polycarboxylate anionic dispersant is 3000 to 100000 Daltons; wherein the slurry has a water to calcium sulfate hemihydrate weight ratio of 0.1-1.5:1. wherein R is selected from the group consisting of -CH 3, and -CH 2 -C -OH, or a Na, K, or NH 4 + salt thereof; and wherein the second monomeric repeating unit B is at least one vinyl sulfonate according to formula II: wherein X is NH or O; R 1 is H or -CH 3; R 2 is a linear or branched alkylene group having the formula -(C n H 2n)-, wherein n=2 to 6; M= H, Na, K, or NH 4 +; wherein the molar ratio of the first repeating unit A to the second repeating unit B is A is between 1:9 and 9:1; wherein the weight average molecular weight of the linear polycarboxylate anionic dispersant is 3000 to 100000 Daltons; wherein the slurry has a water to calcium sulfate hemihydrate weight ratio of 0.1-1.5:1. wherein X is NH or O; R 1 is H or -CH 3; R 2 is a linear or branched alkylene group having the formula -(C n H 2n)-, wherein n=2 to 6; M= H, Na, K, or NH 4 +; wherein the molar ratio of the first repeating unit A to the second repeating unit B is A is between 1:9 and 9:1; wherein the weight average molecular weight of the linear polycarboxylate anionic dispersant is 3000 to 100000 Daltons; wherein the slurry has a water to calcium sulfate hemihydrate weight ratio of 0.1-1.5:1.