| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for recovering and using a sludge without discarding it by reproducing the sludge generated by a washing wastewater treatment after a phosphate formation treatment as a phosphate pigment and the phosphate pigment obtained by the method. SOLUTION: A manufacturing method for a pigment including a process (1) to do the phosphate formation treatment, a process (2) to do a washing treatment after the process (1), a process (3) to do an electrolysis treatment of the washing wastewater in the process (2) and a process (4) to dry the sludge generated by the process (3) by a drum dryer is provided. The pigment obtained by the manufacturing method has an average particle diameter of 1 to 50μm, includes water soluble part of 0.1 to 1.0 mass % and has a true specific gravity of 1.5 or 2.5.</p> |
