US 12,479,745 B2
Method for treating polluted acidic wastewater from smelting with activated pyrite concentrate
Yong Yang, Kunming (CN); Keyuan Sun, Kunming (CN); Weiwei Liu, Kunming (CN); Xingyong Qin, Kunming (CN); Huajun Chen, Kunming (CN); Guohuan Xiong, Kunming (CN); Yanbing Liu, Kunming (CN); Wei Zou, Kunming (CN); Hongxu Zhu, Kunming (CN); Anlei Yue, Kunming (CN); Sen Yan, Kunming (CN); and Weizhi Diao, Kunming (CN)
Assigned to KUNMING METALLURGICAL RESEARCH INSTITUTE CO., LTD., Kunming (CN)
Filed by KUNMING METALLURGICAL RESEARCH INSTITUTE CO., LTD., Kunming (CN)
Filed on Jun. 13, 2025, as Appl. No. 19/237,046.
Application 19/237,046 is a continuation of application No. PCT/CN2024/135092, filed on Nov. 28, 2024.
Claims priority of application No. 202410002536.0 (CN), filed on Jan. 2, 2024.
Prior Publication US 2025/0304476 A1, Oct. 2, 2025
Int. Cl. C02F 1/66 (2023.01); C01G 49/12 (2006.01); C02F 1/36 (2023.01); C02F 1/52 (2023.01); C02F 1/00 (2023.01); C02F 103/16 (2006.01)
CPC C02F 1/66 (2013.01) [C01G 49/12 (2013.01); C02F 1/36 (2013.01); C02F 1/5236 (2013.01); C01P 2006/80 (2013.01); C02F 2001/007 (2013.01); C02F 2103/16 (2013.01); C02F 2209/02 (2013.01); C02F 2209/06 (2013.01); C02F 2209/22 (2013.01); C02F 2209/44 (2013.01); C02F 2301/026 (2013.01); C02F 2305/00 (2013.01)] 9 Claims
 
1. A method for treating a polluted acidic wastewater from a smelting with an activated pyrite concentrate, comprising:
A, a pyrite concentrate pretreatment: drying and grinding a pyrite concentrate to produce a pyrite concentrate powder, and washing the pyrite concentrate powder twice with purified water and absolute ethanol successively to produce a washed pyrite concentrate powder for a later use, wherein the pyrite concentrate comprises the following components: 42.56% to 48.95% of Fe, 43.28% to 49.26% of S, 3.0% or less of SiO2, 1.12% or less of Zn, and 0.44% or less of Pb;
B, a pyrite concentrate activation: thoroughly mixing the washed pyrite concentrate powder and a Na2S powder in a mass ratio of 10:(1-2) to produce a mixed powder; feeding the mixed powder into a reactor, and adding purified water, wherein a mass-to-volume ratio of the mixed powder to the purified water is (400-500) g:1,000 mL; allowing a reaction for 3.5 h to 4.5 h at 105° C. to 115° C., 0.3 MPa to 0.5 MPa, and 160 r/min to 200 r/min, and naturally cooling to a room temperature to produce a reaction solution; filtering the reaction solution to produce the activated pyrite concentrate; and subjecting the activated pyrite concentrate to an aeration and a standing, a drying, and a grinding to produce an activated pyrite concentrate powder for a later use, wherein the activated pyrite concentrate powder comprises the following components: 37.28% to 42.56% of Fe, 42.64% to 48.54% of S, 4.76% to 8.65% of Na, 2.35% or less of SiO2, 0.97% or less of Zn, and 0.38% or less of Pb; and
C, a polluted acidic wastewater treatment: adding a first lime slurry to the polluted acidic wastewater to adjust a pH of the polluted acidic wastewater to 2.0 to 4.0; adding the activated pyrite concentrate powder at an amount of 12.0 g to 20.0 g per 1.0 L of the polluted acidic wastewater, and allowing an ultrasonic treatment at an ultrasonic frequency of 25 kHz to 28 kHz, wherein a temperature of the polluted acidic wastewater is maintained at 28° C. to 32° C., a continuous stirring is conducted at a rotational speed of 140 r/min to 180 r/min for 5 h to 6 h, and a dissolved oxygen content of the polluted acidic wastewater is maintained at 10.0 mg/L to 15.0 mg/L; allowing a first static settlement for 30 min to 60 min to produce a first supernatant; adding a second lime slurry to the first supernatant to adjust a pH of the first supernatant to 8.0 to 9.0; further allowing a second static settlement for 30 min to 60 min to produce a second supernatant; and centrifuging the second supernatant to obtain a final treated water.