Method for absorbing and reclaiming palladium from palladium-containing waste liquid by ion exchange resin

Abstract

The invention relates to a process for adsorbing and recycling palladium in waste liquor containing palladium by ion exchange resin, belonging to the technical field of the separation method utilizing the ion exchange resin as sorbent to treat liquid. The step of the process is to dispose weakly acidic acrylic acid type cation exchange resin as absorption bed layers and utilize the absorption bed layers to absorb the waste liquor containing palladium, absorption time is 40-60 minutes, and operation temperature is 25-85DEG C. Utilizing hydrochloric acid to desorb the waste liquor containing palladium, desorption time is 60-80 minutes, and the operation temperature is 25-85DEG C. Evaporating, concentrating and crystallizing the desorption liquor containing palladium after desorbing, and at last, recycled palladium compound PdCl2 is obtained. The process also can employ repeated cycle to absorb and desorb 2-8 times. The recovery rate of palladium can reach above 72% by employing the process of the invention. Recovery cost is low. The required equipment and technique is simple, and the operation is easy. Resin is easy to regenerate, and the resin after desorption can be used in repeated cycle.

Description

technical field [0001] The technical scheme of the present invention relates to a separation method using ion exchange resin as an adsorbent to treat liquid, specifically, a method for using ion exchange resin to adsorb and recover palladium in palladium-containing waste liquid. Background technique [0002] Most methods of recovering palladium from waste catalysts, waste electronic instruments and waste electroplating liquid secondary resources have to go through the process of extraction and recovery from the solution. Common methods for recovering palladium from solutions in the prior art include precipitation, activated carbon adsorption and solvent extraction. The precipitation method is to add Zn powder or Al powder to the palladium-containing solution to replace palladium, and the obtained crude palladium is boiled and chlorinated with acid, and then undergoes a complicated refining process of dichlorodiamine sub-palladium to obtain palladium powder with high purity. ...

AI Technical Summary

Problems solved by technology

CN1388256 discloses a method for reclaiming palladium from low-concentration palladium ion waste liquid with bacterial cells, wherein the filtered bacterial cells that have absorbed palladium need to be placed at room temperature for 6-48 hours, and finally burned at 550-800 ° C for 1.5 -3 hours, so the operation period of this method is long, and the bacterial cells cannot be reused

CN1400322 discloses a method for separating platinum, palladium, iridium and gold. It uses weakly basic styrene anion exchange resin as stationary phase and hydrochloric acid medium as mobile phase to realize the separation of platinum, palladium, iridium, gold and base metals. The pH of the waste liquid is less than 7, and the adsorbed resin needs to be rinsed in sections, using 0.5mol / L-2mol / L NH 4 CL+1mol / L-3mol / L NH 3 ·H 2 O desorbs palladium, and this method step is various, and certain limitation is arranged on experimental condition and operation condition; CN85100240 has disclosed gold and palladium in reclaiming electroplating waste liquid with mercaptoamine type chelating resin, and the pH value<7 of waste liquid, The resin saturated with palladium needs to be baked in a muffle furnace at 900°C for 2 hours

In a word, the above-mentioned existing methods all have the disadvantages that the recovery rate of palladium is not high, and the operating conditions are complicated.