Sustainable Mining and Metallurgy

High temperature arsenic-containing flue gas will be produced when arsenic-containing concentrate is treated in non-ferrous smelting industry. The conventional arsenic flue gas recovery process is a one-step quenching method, which has problems such as low grade of arsenic trioxide products in crude arsenic, low dust collection efficiency and service life of electrostatic precipitators. Therefore, this paper proposed a new process of arsenic-containing flue gas grading and quenching treatment, that is, to cool the flue gas by grading absorption, to set up a first-stage quenching tower at the inlet of the electrostatic precipitator, to spray and absorb the impurities such as sulfur trioxide, hydrogen fluoride and hydrogen chloride in the flue gas, and to set up a second-stage quenching tower at the outlet of the electrostatic precipitator. The flue gas is rapidly cooled by spraying liquid water, which effectively improves the arsenic trioxide grade in the crude arsenic in the arsenic recovery system after the second-stage quenching tower. After the process optimization, the grade of arsenic trioxide produced is more than 95%, which is much higher than the grade of 70%-80% of arsenic trioxide produced by one-step quenching method, and the recovery rate of valuable metals such as gold, silver and copper in flue gas is improved. When the ore grade is the same, the grading treatment process can greatly reduce the crude arsenic production and the corresponding disposal cost of the arsenic collection system, which is more conducive to the resource utilization of crude arsenic and can bring obvious economic benefits to the enterprise.