Waste diachylon hydrothermal reduction conversion and low-temperature reduction smelting method

Abstract

The invention discloses a waste diachylon hydrothermal reduction conversion and low-temperature reduction smelting method. Waste diachylon and alkali solution are pulped to feed in a reducing agent to add in a high-pressure reaction kettle for reaction under requested temperature and nitrogen partial pressure; after the reaction time is reached, the solid-liquid separation is performed; sodium sulfate is prepared by hydrothermal conversion liquid; hydrothermal conversion slag and starch are fully mixed for low-temperature reduction smelting by an indirect heating mode; and a produced lead bullion is further purified by electrolytic refining. Firstly, the hydrothermal conversion is performed in presence of both alkali and the reducing agent to realize dual purposes of deep conversion desulfurization and reduction conversion of the waste diachylon; and then, the starch serves as the reducing agent under the indirect heating condition to realize the purpose of producing the lead bullion through low-temperature reduction smelting of hydrothermal conversion slag. The desulfurization rate and the lead dioxide reduction rate both reach above 99.0%; the direct yield of lead reaches above 96.0%; the smelting temperature in the low-temperature reduction smelting process is reduced to 800-850 DEG C; and the method has such advantages as simple operation in the technological process, stable technological index, low labor intensity and low production cost.

Description

technical field [0001] The invention relates to hydrometallurgy and pyrometallurgy processes in the field of nonferrous metallurgy, in particular to a combined method of hydrometallurgy and pyrometallurgy for hydrothermal reduction conversion and low-temperature reduction smelting 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...

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Problems solved by technology

Although we use the deep conversion method of hydrothermal reduction to completely convert the waste lead paste, how to smelt the conversion slag into crude lead? If the existing pyrotechnics is used to smelt crude lead, it is necessary to add reducing agent pulverized coal or coke, and there is a large amount of SiO in their combustion ash 2 and Fe 2 o 3 , all need to make FeO-SiO 2 - CaO ternary system high melting point slag removal (melting point is about 1100-1200 ℃), which greatly increases the production cost of the existing pyrotechnic process, and it is difficult to effectively control the mixture of pulverized coal combustion flue gas and smelting lead-containing flue gas

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