METHOD OF PRODUCING MANGANESE (II) FUMARATE FROM MANGANESE METAL AND MANGANESE (III) OXIDE

摘要

FIELD: chemistry.;SUBSTANCE: invention relates to an improved method of producing manganese (II) fumarate from manganese metal and its oxide (III) through direct reaction of the metal and its oxide Mn₂O₃ with an acid in the presence of a liquid phase and a stimulating iodine additive in a vertical type bead mill with glass beads as grinding agent. The metal and its oxide are loaded in molar ratio (2±0.1):1 in total amount of 7.87 to 10.93% of the mass of the load. Acid is added with 15 to 25% excess of the calculated value, equal to the number of moles of metal and twice the number of moles of metal oxide in the load. The base of the liquid phase is isoamyl alcohol, in which the iodine stimulating additive is dissolved in amount of 0.02 to 0.05 mol/kg. Glass beads are loaded first, in mass ratio to the reaction mixture of 1.35:1, and then later the liquid phase solvent, acid and stimulating additive, and after brief stirring, metal oxide and metal, stirring all the while. Taking this moment as the beginning of the process, forced cooling is introduced right away. Operating temperature is stabilised in the range 33 to 45°C and in this mode, the process is carried out until virtually quantitative conversion of metal and its oxide to the target salt, after which stirring and forced cooling are stopped. The reaction mixture is separated from the glass beads, cooled to temperature 5 to 6°C and kept at that temperature for 1 to 2 hours. The solid phase of the target salt is filtered off and washed with isoamyl on a filter cooled to approximately the same temperature, after which it is taken for purification by recrystallisation. The filtrate and the cleaning solvent, containing excess acid, the bulk of the stimulating additive and a certain amount of dissolved target salt, are returned for loading in the repeated process. The process is carried out in light temperature conditions. The target substance can be easily separated.;EFFECT: design of a low-waste method, which allows for obtaining target product from available manganese oxide with an easy to implement process.;9 ex