Method for preparing Na2[Pb(OH)4] solution and method for recycling lead from lead-containing waste

Abstract

A method for recycling lead from the lead-containing waste comprises the following steps of: converting the lead of the lead-containing waste to a Na2[Pb(OH)4] solution; injecting the Na2[Pb(OH)4] solution in the cathode chamber of an electrolytic cell, and introducing hydrogen gas and a NaOH solution in the anode chamber of the electrolytic cell; adjusting the voltage between the cathode and the anode to ensure that the electrolytic cell is always in a working state of continuous generation; and recycling lead at the cathode of the cathode chamber. A method for preparing the Na2[Pb(OH)4] solution comprises the following steps of: converting the lead and lead oxides of the lead-containing waste to lead sulfate; using the lead sulfate and an excess NaOH solution to react, generate Na2[Pb(OH)4] and obtain a mixed solution with Na2[Pb(OH)4] and NaOH; filtering the mixed solution at 40-115 DEG C; adding a little high purity PbO in the filtrate to ensure that the Na2[Pb(OH)4] of the solution is converted to PbO crystals; and separating out the PbO crystals, and dissolving the crystals in NaOH again to prepare the Na2[Pb(OH)4] solution. By adopting the methods, the power consumption can be obviously reduced and high purity lead can be recycled.

Description

technical field [0001] The invention belongs to the technical field of lead recovery by electrolysis. The invention relates to a method for recovering lead from lead-containing waste by electrolysis. The method does not need to use an external circuit to provide electric energy, and uses the interaction between two electrodes generated by the lead compound and the reducing agent itself during the oxidation-reduction reaction process. The potential difference is used to realize the recovery of high-purity metallic lead. In addition, the present invention also provides a method for preparing Na 2 [Pb(OH) 4 ] solution method. Background technique [0002] Regeneration and recycling of resources are key technologies for the sustainable development of human society. Since the French engineer Plante proposed lead-acid batteries in 1859, lead-acid batteries have been widely used in electric vehicles, automobiles and uninterruptible UPS power supplies due to their cheap price, m...

AI Technical Summary

Problems solved by technology

Although this process can directly obtain electrolytic lead, the shortcomings of the process itself have seriously restricted the industrialization process of the process. The energy consumption of lead is generally 700 to 950KWh; there are relatively high concentrations of lead ions and fluoroboric (silicon) acid remaining in the waste liquid

[0007] Although this process has reduced the toxicity problem caused by the use of fluorine-containing compounds to a certain extent, its main disadvantages are: the energy consumption of the electrolysis process is still high, and the single-cell voltage is as high as 2.9 to 3.3V, resulting in a large amount of secondary lead per ton. The energy consumption is 850 to 1100KWh; a large amount of lead dioxide is produced by the anode, and the cathode current density is low, generally only 150-250A / m 2 , and the lead obtained by electrolysis is a kind of sponge lead with a high specific area, which is easy to cause short circuit of cathode and anode in the electrolysis process, and oxidation in the high temperature melting process; and a large amount of tartaric acid is consumed in the electrolysis process, and the introduction of organic matter increases the solution Resistance and electrolytic tank pressure, coupled with the high toxicity of organic lead compound waste liquid, make post-treatment more difficult

[0014] (1) In the recovery process of acidic wet lead, various processes have different levels of power consumption. In particular, the energy consumption per ton of lead in acidic soluble lead salts is as high as 600 to 1000 kWh, which is much higher than The existing fire method has a level of 550 degrees per ton of lead;

[0015] (2) In the process of electrolytic recovery of waste materials containing lead oxide, the complexing process of lead oxide needs to use complexing agents, such as potassium sodium tartrate, citric acid, etc., which increases the cost of the lead recovery process;

[0016] (3) The current lead recovery process is difficult to achieve high lead purity through one-time electrolysis while taking into account energy consumption;

[0017] (4) Most of the current lead recovery processes are not easy to realize continuous and cyclic operation. For example, the alkaline solid phase paste method adopts non-continuous mechanized operation, which causes great difficulties to the industrialization of lead recovery

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