Preparation method capable of absorbing Ca material from magnesium sulfate waste water

The invention relates to a preparation method capable of absorbing a Ca material from magnesium sulfate waste water. According to the method, a reusable absorptive powder material with high selectively to calcium ions can be obtained by taking cheap attapulgite clay as a carrier material and adopting a Ca mark template reaction technology, and processes such as Ca mark template polymerization modification and molecular cross linkage. The method is mainly used for separating the calcium ions and magnesium ions from calcium-magnesium mixed liquid, and for a decalcification procedure of the waste water of the nickel laterite ore metallurgical industry.