Method for producing agricultural fertilizer by using waste liquid of monosodium glutamate

Abstract

The invention discloses a method for producing farm fertilizer by monosodium glutamate tail washings with a primary raw materials: monosodium glutamate tail washings containing a solid content of 8-50%, active sludge with an organic matter content more than 50%, sulphuric acid with a concentration of 90-98%, potassium chloride with a pureness of 95-98%, powdered monoammonium phosphate with a total nutrition of 55-60%, liquid ammonia. The potasium bisulfate is got by a reaction of potassium chloride and concentrated sulfuric acid. A mixing ammonium liquid is obtained by introducing the powdered monoammonium phosphate and active sludge into the monosodium glutamate tail washings. The mixing ammonium liquid mixes with the potasium bisulfate to form mixed acid. Slurry is produced by feeding the gas ammonia into the mixed acid for a neutralization reaction. The slurry produces the compound fertilizer of potassium sulfate style and organic-mineral compound fertilizers by spouting of stock, prilling and drying. The method can make the material fully mix and get an even slurry liquid with an excellent flowability which fits for the spouting of stock and prilling. Therefore, it may produce standard compound fertilizer containing organic matters and organic-mineral compound fertilizers in potassium sulfate style with a low, medium, high concentration.

Description

technical field [0001] The invention relates to a method for producing agricultural fertilizers, more precisely a method for producing potassium sulfate type compound fertilizer containing organic matter and potassium sulfate type organic-inorganic compound fertilizer by using monosodium glutamate tail liquid. Background technique [0002] my country is a big producer of MSG, and its annual output ranks first in the world. During the production process of each ton of MSG, 15 tons of high-concentration organic tail liquid will be discharged. The MSG tail liquid contains 8% solids, and the N, P, and K contained in it , S, and organic amino acids can be fully utilized by agriculture to increase production, improve soil, and control MSG wastewater pollution. [0003] There are two common treatment methods now: one is to concentrate the tail liquid into a concentrated liquid with a solid content of about 40%, and then spray and granulate the concentrated liquid to make a fertilize...

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Problems solved by technology

[0003] There are two common treatment methods now: one is to concentrate the tail liquid into a concentrated liquid with a solid content of about 40%, and then spray and granulate the concentrated liquid to make a fertilizer with a nitrogen content of 16%, which does not meet the requirements. National fertilizer standards have caused great difficulties in market sales. At the same time, because of the low pH value of this fertilizer (around 3), long-term use will have adverse effects on the soil; and because of the high water content of the concentrate, the spray granulation is dry. The production capacity of the machine is reduced; the other is to concentrate the tail liquid into a concentrated liquid with a solid content of about 40%, spray-dry the concentrated liquid into powder, and then add solid phosphate fertilizer and potassium fertilizer for secondary drum granulation to produce granules Shaped compound fertilizer, because this method requires secondary processing of fertilizer, wastes energy, and the product quality is poor, so this process is rarely used

[0004] Chinese patent CN00116087.7 ​​discloses the "method for producing compound fertilizer from monosodium glutamate organic waste water". 24.5-25.5 degree concentrated solution, the concentrated solution contains 16% nitrogen and 20% sulfur, then put it into the stirring tank, add monoammonium phosphate or potassium chloride, or a mixture of monoammonium phosphate and potassium chloride, and stir to form a homogenous slurry , pumped into the spray granulator, and then cooled and sieved into a series of compound fertilizers. The biggest defect of this process is that the neutralized MSG concentrate can only dissolve a small amount of powdered monoammonium phosphate, and potassium chloride is almost insoluble in the MSG concentrate. liquid, so this process technology is limited to theory and cannot be applied in actual production

In addition, now all monosodium glutamate manufacturers are directly spraying and granulating the concentrated monosodium glutamate tail liquid. Since the concentrated liquid is only concentrated to about 40% solid content, the monosodium glutamate concentrated liquid contains about 60% water, so it is directly processed Shotcrete granulation consumes a lot of energy per ton of product fertilizer, which makes the production capacity of the spray granulator very low, and the product only contains 16% nitrogen, which is a fertilizer that does not meet any national or industry or local agricultural fertilizer standards. fertilizer, so it caused great difficulties to the sale of fertilizer

[0005] In summary, at present, there is no better method to produce agricultural fertilizers that meet the standards with MSG tail liquid at home and abroad.

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