| 摘要 |
<p>[Problem] When producing lithium hexafluorophosphate or an electrolyte resulting from dissolving lithium hexafluorophosphate in an organic solvent, to reduce the phosphorus concentration and fluorine concentration in the wastewater that arises to a level such that it is possible to discharge into the sea or the like with little dilution, performing said reduction by means of an easy process and with little energy loss. [Solution] A method for processing wastewater containing fluorophosphate compounds is characterized by having: a breakdown step for breaking down fluorophosphate compounds by means of causing the inclusion of hydrogen chloride in the wastewater containing fluorophosphate compounds in a manner so that the concentration of hydrogen chloride becomes 11-25 mass%, and then heating the wastewater to at least 50°C and less than 80°C; an immobilizing step for immobilizing phosphorus and fluorine in the wastewater by adding a calcium compound to the wastewater after the breakdown step, causing the pH of the wastewater to be at least 6; and a solid-liquid separation step for obtaining wastewater with a reduced concentration of fluorine and phosphorus by eliminating the solid material immobilized in the immobilizing step.</p> |
