Hydrothermal deep conversion desulfurization method for waste lead plaster of lead-acid storage battery

Abstract

The invention discloses a hydrothermal deep conversion desulfurization method for waste lead plaster of a lead-acid storage battery. The method includes the steps that the waste lead plaster and aqueous alkali are mixed and then added into a high pressure reactor, and reacting is carried out under the required temperature and nitrogen partial pressure, so that lead sulfate is completely reacted with alkali to remove sulfate radicals; and solid-liquid separation is conducted after the requirement for reaction time is met, sodium sulfate is recovered from desulfuration conversion liquid, and lead is further extracted from desulfuration conversion slug. By the adoption of the hydrothermal mode, the alkaline conversion desulfuration process of the waste lead plaster is strengthened, the sulfate radicals in the waste lead plaster can be removed completely, the consumption of alkaline only accounts for 1.0-1.05 times of the theoretical dose, the desulfurization degree is above 99.0%, and therefore advantage conditions are created for subsequent extraction of lead from the conversion slag.

Description

technical field [0001] The invention relates to a hydrometallurgical process in the field of nonferrous metallurgy, in particular to a hydrometallurgical method for hydrothermal deep conversion desulfurization of waste lead-acid storage battery lead paste. Background technique [0002] Lead is a silvery-white heavy non-ferrous metal. Based on its special physical and chemical properties, it is mainly used to make alloys. Among them, lead-acid batteries are the main consumption area, accounting for more than 80.0% of the world's total lead consumption. Although the weight-to-energy ratio of lead-acid batteries is lower than that of MH-Ni batteries and Li-ion batteries, they are widely used in various fields of the national economy due to their high cost performance, mature technology and good safety performance. More than 70.0% of the secondary battery market share. In recent years, the rapid development of my country's automobile industry has stimulated the rapid developmen...

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Problems solved by technology

The purpose of the desulfurization process of waste lead paste conversion is to remove PbSO from waste lead paste 4 sulfate radical and convert it into lead carbonate or lead hydroxide. The conversion agent used in the desulfurization conversion process mainly includes Na 2 CO 3 、K 2 CO 3 , (NH 4 ) 2 CO 3 , NH 4 HCO 3 , NaOH and KOH, etc. Usually, the removal rate of sulfate radicals in actual operation is only 85-95%. The incomplete desulfurization and low reduction efficiency seriously affect the application effect of this method. The researchers proposed to use supergravity, ball milling and ultrasonic methods Intensified conversion desulfurization process (Pan Junqing et al. Development status of lead-acid battery recycling technology [J]. Journal of Beijing University of Chemical Technology, 2014, 41(3): 1-14.), but still can not achieve the desired effect, the main reason It may be the non-conductive lead sulfate crystals precipitated on the grid of the waste lead-acid battery during the discharge process, which is difficult to react with the reagent in the conventional conversion desulfurization process

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