CN102676837A

CN102676837A - Method for recycling palladium from silver electrolyte by using dimethylglyoxime

Info

Publication number: CN102676837A
Application number: CN201210167124XA
Authority: CN
Inventors: 江继明; 江启明; 黄明; 程兰
Original assignee: SIHUI HONGMING PRECIOUS METAL CO Ltd
Current assignee: SIHUI HONGMING PRECIOUS METAL CO Ltd
Priority date: 2012-05-25
Filing date: 2012-05-25
Publication date: 2012-09-19

Abstract

The invention discloses a method for recycling palladium from a silver electrolyte by using dimethylglyoxime. The method comprises the following steps: adding dimethylglyoxime into a palladium-containing electrolyte for precipitating palladium; performing solid-liquid separation, returning filtrate as an electrolyte, and eluting filter residue with nitric acid acidification water to obtain a dimethylglyoxime palladium crude product; dissolving the dimethylglyoxime palladium crude product with aqua regia, and then precipitating palladium with ammonium chloride; eluting an obtained ammonium chloropalladate precipitate with an ammonium chloride solution until filtrate is colorless; and adding water, heating, and dissolving; filtering, and cooling filtrate; adding ammonia water, complexing and dissolving; cooling, filtering, and eluting the filter residue with ammonia water; adding hydrochloric acid for acidifying filtrate; filtering to obtain a diammonium dichloropalladite precipitate; and reducing the precipitate by hydrazine hydrate to obtain palladium sponge with the grade of 99.99%. Heating and pH regulation are not required, and only quantitative precipitation of palladium is required; the selectivity is good; and the precipitated dimethylglyoxime palladium can achieve a very high purity after simple eluting, so that the palladium purifying process is greatly shortened and the palladium recycling rate is improved; the using amount of dimethylglyoxime is low; and except a small amount of ethanol, other ions are not brought, so that the reuse of the electrolyte is not affected.

Description

A kind of method that adopts dimethylglyoxime to reclaim palladium in the silver electrolyte

Technical field:

The present invention relates to a kind of smelting process of precious metal, be specifically related to a kind of method that adopts dimethylglyoxime to reclaim palladium in the silver electrolyte.

Background technology:

Palladium in the silver electrolytic process anode is had an appointment and 60% is got into electrolytic solution, and the method one that tradition reclaims palladium is use charcoal absorption, but has following shortcoming: gac is wanted pre-treatment and regeneration, and electrolytic solution need be heated to 80-90 ℃ before adsorbing; Hydro-oxidation sodium adjustment PH to 1.5-1.8, and the sodium ion of bringing into run up to behind the finite concentration can the heavy palladium of influence after the re-using of electrolytic solution; Gac not only adsorbs palladium, also adsorbs metals such as a large amount of silver, bismuth, and poor selectivity also increases difficulty to postorder purification palladium.The 2nd, precipitate palladium with xanthate, its shortcoming is: also needs before the deposition electrolytic solution is heated to 80-90 ℃, and adjustment PH to 2.0; The coprecipitation of part silver is also arranged when sinking palladium, can produce a kind of unpleasant gas, contaminate environment when sinking palladium in addition.

Summary of the invention:

The purpose of this invention is to provide a kind of heating and adjust pH of need not, selectivity is good, and purity is high, and the recovery of palladium is high, and the short employing dimethylglyoxime of flow process reclaims the method for palladium in the silver electrolyte.

Employing dimethylglyoxime of the present invention reclaims the method for palladium in the silver electrolyte, it is characterized in that may further comprise the steps:

To contain palladium-silver electrolytic solution and be transferred in the heavy palladium stirred pot, and take by weighing dimethylglyoxime in quality than the ratio of palladium: dimethylglyoxime=1:2.5, and it is dissolved in ethanol; In silver electrolyte, drip the dimethylglyoxime ethanolic soln then while stirring, do not generate the orange-yellow palladium terminal point that is precipitated as to drip dimethylglyoxime at last, after heavy palladium finishes; Through solid-liquid separation, liquid returns as electrolytic solution, and solid use pH is 1 nitric acid soured water washing; It is colourless to be washed till wash water, promptly obtains dimethylglyoxime palladium bullion, and dimethylglyoxime palladium bullion is used aqua regia dissolution; Add the heavy palladium of ammonium chloride then and produce until no chlorine palladium acid ammonia precipitation, it is colourless that gained chlorine palladium acid ammonia precipitation is washed till filtrating with massfraction 10% ammonium chloride solution, and the chlorine palladium acid ammonia precipitation after the washing adds in the pure water of 5 ~ 6 times of its quality; Heating for dissolving is filtered and is obtained ammonium palladous chloride solution, adds ammoniacal liquor complexing dissolving to ammonium palladous chloride solution; The tetrachloro that generates flesh pink when adding ammoniacal liquor earlier closes palladium acid four ammino palladiums deposition, continues to add ammoniacal liquor to PH8-9, and resolution of precipitate becomes the inferior palladium solution of chlorination four amminos of light color; The dissolving postcooling filters, and filtrating adds hcl acidifying, and control PH=1 precipitates; Precipitate complete after-filtration and promptly get the inferior palladium deposition of dichloro two amminos, it is colourless to use massfraction to be that 1% hydrochloric acid is washed till washing lotion again, with Hydrazine Hydrate 80 directly reduction obtain palladium sponge.

The present invention compares and prior art, has the following advantages:

1. the present invention adopts the dimethylglyoxime deposition to reclaim the method for palladium in the silver electrolyte, and silver electrolyte need not heating, need not to adjust pH, and schedule of operation is simple.

2. dimethylglyoxime is good to palladium deposition selectivity, do not precipitate other metals, and palladium can precipitate fully.

3. the sedimentary palladium purity of dimethylglyoxime is high, purifies easily, reclaims palladium according to method of the present invention; The recovery of palladium reaches more than 99%; The content of dimethylglyoxime palladium reaches more than 98%, and the purity of gained palladium is up to more than 99%, and the dimethylglyoxime consumption is little; Do not bring other ions into, electrolytic solution can continue to use behind the heavy palladium.

Description of drawings:

Fig. 1 is recovery technical process of the present invention.

Embodiment:

Below be to further specify to of the present invention, rather than limitation of the present invention.

Embodiment 1:

Silver electrolyte 3000L, its component is: silver-colored 86g/L, palladium 0.43g/L, copper 23g/L.

The silver electrolyte that (1) will contain palladium is transferred to heavy palladium stirred pot; Mass ratio by palladium: dimethylglyoxime=1:2.5 takes by weighing dimethylglyoxime; And it is dissolved in the ethanol; In silver electrolyte, drip the dimethylglyoxime ethanolic soln then while stirring, do not generate the orange-yellow palladium terminal point that is precipitated as to drip dimethylglyoxime at last;

(2) after heavy palladium finishes, adopt press filtration to carry out solid-liquid separation, filtrating argentiferous 86g/L, copper 23g/L, palladium 0.005g/L.Filtrating is returned and is made electrolytic solution.Filter residue is with the nitric acid soured water washing of pH=1.0, and it is colourless to be washed till wash water, promptly obtains dimethylglyoxime palladium bullion;

(3) dimethylglyoxime palladium bullion is used aqua regia dissolution; Add the heavy palladium of ammonium chloride then; Add during heavy palladium behind the ammonium chloride of theoretical amount after amount 5%, obtain chlorine palladium acid ammonia precipitation thus, gained chlorine palladium acid ammonia precipitation with the ammonium chloride solution of massfraction 10% be washed till filtrate colourless.Chlorine palladium acid ammonia precipitation after the washing adds in its quality 5-6 zero(ppm) water doubly, and heating for dissolving is filtered and obtained ammonium palladous chloride solution; Add ammoniacal liquor complexing dissolving to solution, the tetrachloro that generates flesh pink when adding ammoniacal liquor earlier closes palladium acid four ammino palladiums deposition, continues to add ammoniacal liquor to PH8-9; Resolution of precipitate becomes the inferior palladium solution of light chlorination four amminos, and the dissolving postcooling filters; Filter residue is with the ammonia scrubbing of massfraction 1%, and complex solution adds hcl acidifying, and control pH=1.0 precipitates; Precipitate complete after-filtration and promptly get the inferior palladium deposition of egg xanchromatic dichloro two amminos; It is colourless that the inferior palladium deposition of dichloro two amminos is washed till washing lotion with the hydrochloric acid of mass and size mark 1%, and the inferior palladium deposition of dichloro two amminos after the washing is directly reduced the palladium sponge that obtains grade 99.99% with Hydrazine Hydrate 80, and the recovery is 99%.

Claims

1. one kind employing dimethylglyoxime reclaims the method for palladium in the silver electrolyte, it is characterized in that, may further comprise the steps:

To contain palladium-silver electrolytic solution and be transferred in the heavy palladium stirred pot, and take by weighing dimethylglyoxime in quality than the ratio of palladium: dimethylglyoxime=1:2.5, and it is dissolved in ethanol; In silver electrolyte, drip the dimethylglyoxime ethanolic soln then while stirring, do not generate the orange-yellow palladium terminal point that is precipitated as to drip dimethylglyoxime at last, after heavy palladium finishes; Through solid-liquid separation, liquid returns as electrolytic solution, and solid use pH is 1 nitric acid soured water washing; It is colourless to be washed till wash water, promptly obtains dimethylglyoxime palladium bullion, and dimethylglyoxime palladium bullion is used aqua regia dissolution; Add the heavy palladium of ammonium chloride then and produce until no chlorine palladium acid ammonia precipitation, it is colourless that gained chlorine palladium acid ammonia precipitation is washed till filtrating with massfraction 10% ammonium chloride solution, and the chlorine palladium acid ammonia precipitation after the washing adds in the pure water of 5 ~ 6 times of its quality; Heating for dissolving is filtered and is obtained ammonium palladous chloride solution, adds ammoniacal liquor complexing dissolving to ammonium palladous chloride solution; The tetrachloro that generates flesh pink when adding ammoniacal liquor earlier closes palladium acid four ammino palladiums deposition, continues to add ammoniacal liquor to PH8-9, and resolution of precipitate becomes the inferior palladium solution of light chlorination four amminos; The dissolving postcooling filters, and filtrating adds hcl acidifying, and control PH=1 precipitates; Precipitate complete after-filtration and promptly get the inferior palladium deposition of dichloro two amminos, it is colourless to use massfraction to be that 1% hydrochloric acid is washed till washing lotion again, with Hydrazine Hydrate 80 directly reduction obtain palladium sponge.