Method for recovering precious metal platinum in car dead catalyst through pyrogenic process

Abstract

The invention discloses a method for recovering precious metal platinum in a car dead catalyst through a pyrogenic process. The method comprises the steps that (1) the car dead catalyst is pretreated,and then the car dead catalyst is sealed for standby application; (2) the car dead catalyst obtained in the step (1) is evenly mixed with a carbon reducing agent, a trapping agent and a slagging material according to a certain percentage to prepare blocky mixtures; (3) the mixtures obtained in the step (2) are broken to be placed into a direct current electric arc furnace for high-temperature smelting to obtain melted liquid; and (4) upper-layer slag liquid of the melted liquid obtained in the step (3) is poured out to prepare glassy state or wee glass balls, and a lower-layer precious metalplatinum containing alloy is naturally cooled at room temperature. The method is suitable for high-grade materials, can be used for recovering precious metal platinum from low-grade materials, the process is simple, and the period is short.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for recovering precious metal platinum in waste automobile catalysts by means of pyrolysis. Background technique [0002] Due to its excellent physical and chemical properties, precious metal platinum is widely used in agriculture, petroleum industry, military industry, high-tech and other industries. Especially with the rapid development of science and technology in recent years, the demand for precious metal platinum in various industries is increasing day by day. At this stage, the main sources of precious metal platinum are mineral resources and secondary resources. However, the mineral resources of the precious metal platinum are extremely limited. In addition, the grade of platinum in the raw ore is low and most of them are paragenetic ores. As a result, it has become unsustainable to use mineral resources to extract precious metal platinum to meet ...

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Problems solved by technology

[0005] The main problem with the method of using Cu as the collector is: the process of reprocessing the Pt-Cu alloy in the later stage of smelting to obtain platinum metal. Generally, there are two methods to obtain platinum metal, oxidative blowing and electrolysis of anode copper, but these two methods It has the disadvantages of increasing the cost of extracting platinum metal, increasing the entire extraction cycle, and the subsequent waste residue and waste liquid are not easy to handle.

However, the use of Fe as the collector mainly has the following disadvantages: (1) most of the existing methods use metallic iron as the collector, and the density of metallic iron is relatively high, and most of the platinum in the spent catalyst is a platinum-containing compound. The compound needs to be reduced to metal platinum by a reducing agent to form an alloy with the collector. In the preparation process of the existing method, due to the high density of iron, when the platinum compound has not been transformed into metal platinum, some or even large Part of the Fe sinks to the bottom of the melt, resulting in waste of the collector Fe and insufficient capture of the platinum in the spent catalyst; (2) In the existing method of using Fe as the collector, most of the smelting equipment used is a resistor Furnaces, induction furnaces, etc., resistance furnaces, induction furnaces take a long time to reach the melting temperature (1600 ° C ~ 2000 ° C), resulting in a longer melting time for the mixed material, resulting in melt viscosity that cannot meet the requirements for rapid separation of slag and gold in a short time. Make the separation time of slag and gold longer, so that the cycle of the whole extraction of metal platinum is prolonged, which increases the cost of the extraction process; (3) in the existing method of using Fe as the trapping agent, the waste residue produced cannot be directly discarded and must be further processed It can be discarded later, which increases the process cost and prolongs the extraction cycle

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