a method for manufacturing the nano-size hematite powder against red-tide

摘要

PURPOSE: Provided is a method for preparing hematite ultra-fine particles with high red tide control efficiency, capable of rapidly removing red tide in easy way as mush as a loess suspension method and completely collapsing cells of harmful plankton, thereby reducing consumption of red tide control agent and economically and nature-friendly controlling red tide. CONSTITUTION: The method comprises the steps of (a) dispersing hematite starting material in aqueous solution with a ratio of 1:2.5 to 1:6, wherein the aqueous solution is a sulfuric acid or hydrochloric acid with pH of -0.1 to -0.5, (b) heating and mixing the hematite aqueous solution for 3 hours at a temperature of 70 to 100C, (c) recovering hematite ultra-fine particles with no greater than 100 nm by separating the hematite aqueous solution, wherein the staring material is commercially used hematite powder, natural hematite powder, waste iron oxide, waste catalyst mainly containing Fe2O3 for petroleum refining, or red clay.