Method for preparing polyferric chloride by using wastewater produced in pickling of steel with hydrochloric acid

• Main Authors: ZHANG DAKUI, XUE ZHANQIANG, WANG LIYING, ZHANG ZHAN, MU CHUNFENG
• Format: Patent
• Language: Chinese; English
• Published: 22.01.2019
• Subjects: CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; INORGANIC CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

The invention relates to a method for preparing polyferric chloride by using wastewater produced in pickling of steel with hydrochloric acid. The method comprises the following steps: pretreating hydrochloric acid pickling wastewater, and quantitatively feeding the filtered hydrochloric acid pickling wastewater into a reaction kettle; adding a phosphate buffer in batches, wherein 0.03 to 0.04 tonof the phosphate buffer is added for per ton of the concentrated hydrochloric acid pickling wastewater; carrying out sufficient stirring to completely dissolve the phosphate buffer; and adding an oxidizing agent under the conditions of stirring and constant-temperature heating for an oxidative polymerization reaction, wherein the concentration of the oxidizing agent is 120-150 mg/L, 0.7 to 1.1 kg/h of the oxidizing agent is added for per ton of the concentrated hydrochloric acid pickling wastewater, the rotating speed of an agitator in a reaction vessel is 200 to 400 rpm, a reaction temperature is 40 to 60 DEG C, and