Method for selectively separating zinc, chromium and iron and recovering multiple metals in electroplating sludge
A selective, zinc-ferrochrome technology, applied in copper sulfate, nickel sulfate and other directions, can solve the problems of difficult recovery of metals, easy generation of waste water, etc., and achieve the effect of eliminating chromium heavy metal waste water, reducing reagent consumption, and reducing the amount of waste residue.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0039] Please refer to figure 1 , the feed liquid is the iron, chromium, zinc sulfate solution prepared in the laboratory: the feed liquid contains Cr4.9g / L, Fe2.0g / L, Zn 1.6g / L. Select sodium sulfite as the reducing agent, add sodium sulfite according to 1.5 times the theoretical amount of the reaction required for complete reduction of iron and chromium, adjust the pH to 2.0 with sulfuric acid, add sodium phosphate according to the molar ratio of phosphate to chromium ion 1.1, and keep stirring at 90 ℃ for 60min. The coarse precipitate of chromium phosphate was obtained by filtration. The concentrations of chromium, iron and zinc in the filtrate were 0.07g / L, 1.67g / L and 1.57g / L, respectively, the chromium deposition rate was 98.59%, the iron deposition rate was 19.21%, and the zinc deposition rate was 98.59% 1.21%. The filter residue is the chromium removal residue, and the filtrate is the chromium removal liquid.
[0040]Take 5g of fresh chromium removal residue, wash wi...
Embodiment 2
[0043] Solution preparation:
[0044] Formulation of Cr under acidic conditions 3+ / Fe 2+ / Zn 2+ Mixed solution ([Cr 3+ ] 初始 =5.00g / L, [Fe 2+ ] 初始 =3.15g / L, [Zn 2+ ] 初始 =2.78g / L);
[0045] Prepare a certain volume of sodium phosphate dodecahydrate solution; prepare a certain volume of sodium hydroxide solution (4.5mol / L).
[0046] Pretreatment of chromium iron zinc solution:
[0047] Add a small amount of sodium sulfite to reduce the pretreatment of chromium-iron-zinc solution to ensure that all the iron in the solution is Fe 2+ form exists.
[0048] Precipitation experiment (atmospheric pressure):
[0049] Measure 0.5L of the ferrochromium mixed solution with a graduated cylinder, add one or two drops of the mixed solution dropwise to a 5% potassium thiocyanate solution, and detect whether there is Fe or not. 3+ Exist (if there is red, add a small amount of sodium sulfite to reduce), if not, add sulfuric acid dropwise to adjust the pH of the solution = 2.0 (measu...
Embodiment 3
[0061] Please refer to figure 2 , the electroplating sludge is dissolved with sulfuric acid to obtain calcium sulfate solid and leaching solution, wherein the leaching solution is Cu, Cr, Ni, Zn, Fe mixed acid solution ([Cu 2+ ] 初始 =1.03g / L, [Ni 2+ ] 初始 =2.04g / L, [Cr 3+ ] 初始 =5.00g / L, [Fe 2+ ] 初始 =3.15g / L, [Zn 2+ ] 初始 =2.78g / L)).
[0062] In the leaching solution, the extractant LIX984 is used to selectively extract copper, and the organic phase after copper extraction is back-extracted with sulfuric acid to obtain copper sulfate.
[0063] In the raffinate phase after extraction of copper, the extraction agent HBL110 is used to selectively extract nickel, and the organic phase after extraction of nickel is back-extracted with sulfuric acid to obtain nickel sulfate.
[0064] Sodium phosphate is added to the raffinate phase after nickel extraction and stirred, and after filtration and separation, chromium phosphate filter residue and iron-containing filtrate are obtai...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More