METHOD OF PRODUCING CHELATE COMPLEXES BASED ON BIOACTIVE SALTS OF LIGNOSULPHONIC ACIDS AND BIOGENIC METALS Russian patent published in 2024 - IPC C08H7/00 C05F11/00 C05G5/23 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for synthesis of chelate complexes based on lignosulphonates and biogenic metals used in agriculture as microfertilizers, in animal breeding as a fodder additive, as well as in production of food microelement additives. Method of producing chelate complexes is characterized by that nitration of lignosulphonates is carried out by adding 15–20 wt.% aqueous solution of lignosulphonates of nitric acid solution with concentration of 30.0–55.0 wt.% with constant stirring and maintaining temperature in range of 25–35 °C. Salts of inorganic biogenic metals are added with constant stirring and while maintaining temperature within 35 to 50 °C not earlier than 30 minutes after completion of addition of nitric acid. After dissolution of all components, the solution is stabilized step-by-step by adding KOH or NH₃⋅H₂O to achieve pH 3.0–3.5 for 30 minutes, after which the solution is finally stabilized by adding potassium hydroxide or ammonium hydroxide to achieve pH 4.5–5.5 for 60 minutes.

EFFECT: providing long-term stability of the liquid target complex with high concentration of retained biogenic metals.

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