Method for producing microelement concentrate

The invention discloses a method for producing microelement concentrate, comprising the following steps: taking the mixture of medical stone, cay and shell which are smashed as a raw material, adding concentrated sulphuric acid and distilled water, stirring continuously in the adding process, causing the concentrated sulphuric acid to react with the mixture, forming a suspension after the completion of the reaction, adding ferrous sulphate in the suspension, and standing for at least 15 hours; stirring again, adding buffer CMG-40 and buffer bicine, standing for at least 72 hours, taking out the clear liquid on the upper layer, and filtering to remove the suspension impurities therein. The invention adopts natural material to extract microelements, reduces the use of chemical agents containing microelements, and can greatly reduce the production cost of seawater crystal; as the natural material contains most microelements in the sea, the types of the microelements in the microelement concentrate are up to 22,