PURPOSE: To use waste animal milk, etc., effectively and to separate and to use solid components contained in animal milk readily, rapidly and harmlessly, by successively adding a first flocculating agent and a second coagulating agent to animal milk and dehydrating flocculated and precipitated solid components.

CONSTITUTION: 0.1W0.5cc first flocculating agent comprising 1g/100cc sodium alginate is added to 100cc animal milk such as waste cow's milk, etc., and 2W2.5cc second coagulating agent comprising a solution of lactic acid or aluminum polychloride containing 10W11wt% aluminum oxide is successively added to the milk to flocculate and to precipitate solid components in the animal milk, which are then dehydrated.