废催化剂选择法浸渣中提取钯新工艺

New Technology for Pd Recovery from Selectively Leached Residue of Waste Palladium Catalyst

在含钯废催化剂的选择溶解法废弃渣中,仍然残留10~100 g/t的Pd,本文分析了可能存在的5个动力学因素(重新吸附、自发扩散、水解、取代、包裹),提出并实验证明采用弱碱性溶液和强配位剂转型是很有效的. 对于磨细至-150目的样品,钯含量由51.6 g/t降低至1.2 g/t,对于同品位球形颗粒料,槽浸渣钯含量降低至3.0 g/t,浸出率分别达97.7%和94.2%;活性炭(AC)直接吸附浸液中的钯,富氧焚烧载钯AC后,采用氨络合法可制得纯度>99.95%的钯粉. 此工艺具有设备要求低、流程简单、金属回收率高等特点.

There is still 10~100 g/t Pd in the selectively leached residue of waste catalyst, and five factors are considered to probably cause the result: reabsorption, diffusion resistance in pores, hydrolysis, partial substitution, inclusion etc. Using weak alkaline leaching agent CN as an alternative was proposed and testified to be effective. By this technique, Pd content in 150 mesh milled residue was dropped from 51.6 g/t to 1.2 g/t. In a 100 t scale vat leaching test with granular materials, Pd was dropped to 3.0 g/t. The leaching recovery is respectively 97.7% and 94.2%. Pd in leaching solution was directly adsorbed with AC (active carbon) with high absorption rate and good selectivity. Pd loaded AC was burned in oxygen-rich fire, and above 99.95% purity of Pd powder was made by the amino-complexing method. This technology has the features of simple process, less facilities required, high metal recovery and high product purity etc.