A kind of preparation method of sodium iron edetate

Abstract

The invention discloses a preparation method of sodium ferric EDTA, comprising the following steps: (1) weighing a predetermined amount of ferrous sulfate heptahydrate and adding it to deionized water; weighing a predetermined amount of bicarbonate, carbonic acid The mixture of salt or bicarbonate and carbonate is added in the ferrous sulfate solution, and the reaction obtains large particle ferrous hydroxide precipitation; Bubbling air is fully oxidized to ferrous hydroxide powder for subsequent use; ( 2) Weigh a predetermined amount of EDTA and sodium hydroxide, add deionized water; (3) according to a predetermined molar ratio, add ferric hydroxide to the solution obtained in the step (2) under agitation powder, adjust the pH to 4.5-6.0, heat to 60 ℃-80 ℃, stir and react for 30min-50min, the solution is filtered and crystallized to obtain the finished product of sodium iron ethylenediaminetetraacetate. The ferric hydroxide prepared by the on-site oxidation of ferrous hydroxide in the method of the invention has high reaction activity, short subsequent chelation reaction time, high product yield and greatly improved production efficiency.

Description

Technical field [0001] The invention relates to a chelated trace element fertilizer, in particular to a preparation method of sodium ferric ethylenediaminetetraacetate. Background technique [0002] Although iron is low in crops, it has two important functions: first, it is an important part of certain enzymes and many electron transport proteins; second, it can regulate the synthesis of chloroplast protein and chlorophyll. Iron deficiency in plants will cause chlorosis between leaf veins, which will affect plant photosynthesis and respiration, resulting in reduced crop yields and quality. The main supplements to iron are inorganic iron fertilizers, such as ferrous sulfate, iron sulfate, ferric chloride, etc., and chelated iron fertilizers, such as sodium iron ethylenediaminetetraacetate, sodium iron diethylenetriaminepentaacetate, Ethylenediamine di-o-hydroxyphenyl sodium iron acetate and so on. Inorganic iron fertilizer is easy to precipitate, has low utilization rate, and is...

AI Technical Summary

Problems solved by technology

[0004] 1. When ferric chloride or ferric sulfate is used as raw material for direct preparation in the process, the product will contain a large amount of inorganic salt by-products such as sodium chloride and sodium sulfate, which will be difficult to separate later and increase the cost of industrial production

[0005] 2. When disodium edetate is used as raw material in the process, there will also be a large amount of sodium ions in the product, which will reduce the purity of the product

[0006] 3. When iron oxide is used to prepare chelated iron, due to the low reactivity of iron oxide, high reaction temperature is required, and the reaction time will be greatly extended at the same time, resulting in high energy consumption and low efficiency.

Colloids are difficult to filter and wash, which will bring difficulties to subsequent production