| 摘要 |
<p>PURPOSE:To obtain a high purity metal copper particle with a desired particle shape and size, in obtaining a copper salt and the metal copper particle by reacting Cu2O with an acid, by controlling a reaction condition. CONSTITUTION:Dilute acid solution is continuously flowed int a reaction tank in such a flow amount that a predetermined stay time is obtained corresponding to the objective particle size of a metal copper particle to be prepared while a Cu2O particle is added at a speed so as to hold the pH of the reaction tank to a predetermined value. If the addition ratio of Cu2O to an acid is made large, the pH of the reaction system becomes high and it is avoided to generate the precipitation of impurities during reaction while, in order to rapidly advance reaction without leaving Clu2O, pH is held to about 2.5 or less. In the next step, a reaction temp. is set to 50 deg.C or less and mutual agglomeration of fine metal copper particles is avoided. In this case, the stay time is a numerical value obtained by dividing the volume of the reaction tank by the inflow and outflow amount of a slurry per a unit time and a metal copper particle with a smaller perticle size is obtained as the stay time becomes shorter. The metal copper particle in a drain liquid is recovered by solid-liquid separation. Furthermore, by raising a reaction temp. to above 50 deg.C, one with a special particle shape can be obtained.</p> |
