| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method in which additional cost is suppressed, halogen and cadmium included in crude zinc oxide can be efficiently removed in production of zinc oxide ore.SOLUTION: A production method of zinc oxide ore includes: a wet process S20 in which fluorine and cadmium are removed; a desiccation heat process S30 in which crude zinc oxide cake passing a wet process S20 is performed by desiccation heat; and a waste water treatment process S40 in which a discharge liquid discharged from the wet process S20 is performed by separation treatment, wherein in the wet process S20, a first wet process ST21 in which cadmium is removed into a first process liquid having a pH of at most 6.5, and a second wet process ST22 in which after the first wet process, fluorine is removed into a second process liquid having a pH of at least 7.0 are performed, in the second wet process ST22, a second pH adjustment liquid that is a waste water treatment rear liquid passing the waste water treatment process S40 is added to the second process liquid, thereby a pH of the second process liquid is optimized.</p> |
