Clean wet-method solid-liquid two-phase electroreduction lead recovery method

Abstract

The invention relates to a wet-method electroreduction clean lead recovery method with closed circulation. In the method, based on an electrochemical principle, a solid-liquid two-phase one-step reduction reaction is performed by establishing a closed electrolyte circulation and by the lead-containing material activation of an active agent and the catalytic oxygen absorption action of a high-efficiency anode so as to convert waste lead storage batteries or the lead-containing waste material from lead storage battery production plants into metal lead directly. Thus, the method is a novel environmentally-friendly and energy-saving wet-method electroreduction lead recovery method, and is a novel technique that can be used for large-scale industrial production.

Description

Technical field: [0001] The invention relates to a clean wet solid-liquid two-phase electrolytic reduction and recovery method for lead, which belongs to the field of waste lead material regeneration lead wet metallurgy. Background technique: [0002] Lead-acid batteries, as an indispensable electrical energy storage device for vehicles such as automobiles, are consumed and scrapped rapidly with the consumption of automobiles and electric vehicles. In 2002, the consumption of lead in lead-acid batteries in my country reached 645,000 tons, an increase of more than 150% over 2000. According to statistics from the China Physical and Chemical Power Industry Association, China's lead consumption will reach more than 2 million tons in 2008, accounting for more than 23% of the world's total lead consumption. Due to the contradiction between the limited existing lead mine resources and the increasing demand, lead prices have risen day by day. How to efficiently recycle lead-acid batter...

AI Technical Summary

Problems solved by technology

In 1985, German patent (DE, 3402338A) and British patent (1368423 and 1428957) successively reported the principle of forming the negative plate of lead-acid battery, fixing the lead paste of waste battery on a metal plate or metal basket, and in dilute sulfuric acid solution As the cathode for electrolytic reduction, metallic lead and sulfuric acid are obtained, but due to the limited solubility of lead sulfate in dilute acid, the current density and laminate thickness are small, resulting in low utilization of equipment, resulting in small cathode reduction depth, high tank pressure, and energy efficiency. Consumption is large; and the concentration of recovered sulfuric acid is only about 10%, thus limiting industrial promotion

Chinese patent ZL2008101114308.3 (method for recycling waste lead-acid battery battery lead by acid-type wet electrolysis) uses dual power sources and activators to greatly increase the reduction speed and efficiency of lead sulfate, and realizes lead-acid battery lead paste and grid The direct reduction of the lead-acid battery realizes the power consumption of 600-700KWh per ton of lead, and can recycle up to 30% of sulfuric acid. The disadvantage is that this process requires separate electrolytic treatment of the monomers of the lead-acid battery during the electrolysis process, which is not easy to achieve large-scale Industrial production

The disadvantage of this method is that due to the complex composition of the waste lead material, there will be a significant difference between each batch of materials due to Pb and PbO 2 The difference in composition leads to a significant difference in the resistance of the paste itself, so the actual electrolysis current varies greatly under constant voltage electrolysis conditions, and it is difficult to determine the end point of electrolysis by using the electrolysis current to drop to 15-35% of the peak current, so in the actual product There is still a lot of unelectrolyzed lead compounds, usually 85-96% electrolyzed

Due to the characteristics of the constant voltage electrolysis current floating change, the actual current in the mid-term of electrolysis is very large, and a large part of the voltage drops on the polarization of the two electrodes and the internal resistance of the solution, which makes the actual power consumption of this method very uneconomical, per ton Lead needs 547-880 degrees of electricity

[0009] Compared with the mature pyrolysis process, although the wet process improves the recovery rate of lead to a certain extent, the power consumption of up to 600-1000 degrees increases the production cost, coupled with the high energy consumption and corrosiveness of acidic electrolysis Large, and the non-continuous mechanized operation of alkaline solid phase paste, it is currently difficult to apply in actual industrialization

Images