Preparation method for magnetic pigment precursor from iron and zinc-containing waste acid solution

• Main Authors: ZHANG YING, LIU JIAYUAN, SHI XIANG, GAN ZAIJING, HE YANGYI, LI MINGRUI, XU XUELI, LU YONGSHENG
• Format: Patent
• Language: Chinese; English
• Published: 02.08.2019
• Subjects: CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; INORGANIC CHEMISTRY; METALLURGY

The invention discloses a preparation method for a magnetic pigment precursor from an iron and zinc-containing waste acid solution. The preparation method comprises the following steps: 1, performingpretreatment: oxidizing all ferrous iron in the iron and zinc-containing waste acid solution into ferric iron by using an oxidant; 2, carrying out iron-ion precipitation: slowly adding an alkaline substance and adjusting the pH of the waste acid solution to be 3.5 to 5.0, thereby making ferric iron completely precipitated, and performing solid-liquid separation to obtain a crude ferric hydroxide product; 3, precipitating and purifying ferric hydroxide: repeatedly washing and carrying out solid-liquid separation on the crude ferric hydroxide product by using a pickling aqueous solution of whichpH is 4.0 to 5.0, and repeating for multiple times to obtain high-purity iron hydroxide; 4, performing calcination: placing high-purity iron hydroxide in a muffle furnace and carrying out high-temperature calcination to obtai