| 摘要 |
Zeolites of small and uniform size are formed having high magnesium exchange capacities. Zeolite A is disclosed having an average particle size less than 1.7 microns, a calcium carbonate exchange capacity of more than 230 mg calcium carbonate per gram zeolite and a magnesium exchange capacity of more than 140 mg magnesium carbonate per gram zeolite. This zeolite A is produced from a reaction mixture having a water to sodium oxide molar ratio of less than 35:1, and a sodium oxide to silica molar ratio of between 1:1 and 4:1, wherein the silica to alumina molar ratio is greater than 3:1 when the sodium oxide to silica molar ratio is less than 4:3 and the sodium oxide to alumina molar ratio is greater than 4:1 when the sodium oxide to silica molar ratio is greater than 4:3. Zeolite X is disclosed having an average particle size less than 2.2 microns, a calcium carbonate exchange capacity of more than 205 mg calcium carbonate per gram zeolite, and a magnesium exchange capacity of more than 130 mg magnesium carbonate per gram zeolite. This zeolite X is produced from a reaction mixture having a silicate alumina molar ratio greater than 5:1. A combination of zerolite A and zeolite X can be produced from the same reaction mixture.
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