US Patent 7927510 Calcium hypochlorite compositions comprising zinc salts and lime

The present invention is directed to a granular water treatment composition, comprising: 35-95 wt % calcium hypochlorite; 1 to 50 wt % magnesium sulfate or a hydrate thereof; 0.1 to 10 wt % lime; and 0.1 to 55 wt % of a water soluble zinc salt or a hydrate thereof; wherein the weight percents are based on the total weight of the composition. The present invention is also directed to a water treatment tablet, comprising 35-95 wt % calcium hypochlorite; 1 to 50 wt % magnesium sulfate or a hydrate thereof; 0.1 to 10 wt % lime; and 0.1 to 10 wt % of a water soluble zinc salt or a hydrate thereof; wherein the weight percents are based on the total weight of the composition.