The invention relates to a
fertilizer preparation method, in particular to a method of utilizing waste liquid and waste residue of corn pulping to prepare
fertilizer, and aims to solve the problem that existing methods of using corn
straw as a
raw material for composting are long in composting time and bad for storage and utilization of
nutrition. The method includes: step 1, feeding corn
straw into a smasher after feeding the corn
straw into a high-speed vibration screen to enable a material to be in a suspended or half-suspended state; step 2, at normal pressure, soaking corn straw
skin in soaking liquid, extruding out low-concentration waste liquid through an extruder after soaking, and collecting the low-concentration waste liquid; step 3, using a two-
roller mill to mill the corn straw
skin raw material after being soaked, feeding size after milling and separating through the two-
roller mill into a high-concentration pulping
machine, extruding out high-concentration waste liquid through the extruder after pulping, and collecting the high-concentration waste liquid; step 4, concentrating the low-concentration waste liquid, and mixing the same with the high-concentration waste liquid and waste residue obtained in the step 1 for composting; step 5, discharging, packaging or mixing with sterilized clay for
granulation to complete. The method is used for preparing the
fertilizer.