Abrégé

Disclosed is a method for recovery of manganese based compounds from dust of an electric furnace, comprising:(i) a first refining process that includes acid cleaning dust containing Mn and filtering the treated dust to recover alkali metals contained in the dust which is dissolved in a filtrate solution, so as to increase content of Mn in the filtered powder mixture (sludge of the dust); (ii) a reduction process that heats the sludge together with a reducing agent to prepare reduced powder; (iii) an impurity removal process that includes dissolving the reduced powder obtained by the reduction process in acid to prepare a solution, adjusting the pH of the solution in a range of 4 to 7 and filtering the solution, so as to remove impurities except Mn in a sludge state and prepare a solution containing dissolved Mn except the impurities; (iv) a process for precipitation of an Mn compound that includes adjusting the pH of the solution without the impurities due to the impurity removal process in a range of 9 to 12 to precipitate the Mn compound; and (v) a process for recovering the Mn compound that includes separating the Mn compound obtained by the precipitation process from the precipitate, and washing and drying the separated product. The present invention is effective for commercial recovery of manganese contained in dust in a state of an Mn compound, and also for additionally recovery of alkali metal compounds as well as byproducts such as ammonium sulfate depending on types or kinds of acid and base used in production of the Mn compound.

Classes IPC  ?

• C01G 45/00 - Composés du manganèse

Abrégé

Disclosed relates to a process for preparing N (5)- ethylglutamines economically without a specific purification process via a simplified and safe process, in which glutamic acid derivatives, represented by formula 1, protected by phthaloyl groups react with ethylamine to cause an amidation and a deprotection reaction in turn under the same reaction condition, thus preparing N (5) -ethylglutamines .

Classes IPC  ?

• C07C 227/26 - Préparation de composés contenant des groupes amino et carboxyle liés au même squelette carboné à partir de composés contenant des groupes carboxyle par réaction avec HCN, ou un de ses sels, et avec des amines, ou à partir d'aminonitriles