| 摘要 |
A process for preparing a ureaform type resin fertilizer as an aqueous suspension which is stable and preferably has an Availability Index of at least 70 which, in a preferred embodiment, comprises: adding urea to an acidic solution of formaldehyde having a pH of 0.25 to 1.75 at a rate of addition to keep the temperature below 98 DEG C. until the mole ratio of formaldehyde to urea is from 3.5:1 to 2.6:1; adjusting the pH of the reaction mixture to between about 5.2 and 6.8 and the temperature from about 75 DEG C. to 92 DEG C. and adding urea until a formaldehyde to urea mole ratio of 0.5:1 to 1.8:1 is attained and the nephelometric turbidity of the reaction mixture is in the range of 200 to 800 NTU units; and then neutralizing the reaction mixture to a basic pH not exceeding about 8.5.
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