Method for efficiently separating vanadium and chromium based on pH regulation and control

A vanadium-chromium, high-efficiency technology, applied in the field of waste water resource utilization, can solve the problems of cumbersome separation steps, etc., and achieve the effect of high separation efficiency, simple operation process and guaranteed product purity

Inactive Publication Date: 2021-07-09
NANJING UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] In view of the cumbersome separation steps of vanadium and chromium in the existing vanadium and chromium wastewater or the problem of entraining impurity ions when pH is adjusted to form precipitates, the present invention provides a method for efficiently separating vanadium and chromium based on pH control, which can achieve vanadium and chromium by simple pH control. Chromium is effectively separated without precipitation or entrainment, and has the advantages of high vanadium-chromium separation efficiency, high recovery rate, simple process and low cost

Method used

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  • Method for efficiently separating vanadium and chromium based on pH regulation and control
  • Method for efficiently separating vanadium and chromium based on pH regulation and control
  • Method for efficiently separating vanadium and chromium based on pH regulation and control

Examples

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Effect test

Embodiment 1

[0056] 1) Take 500mL of a mixed solution containing pentavalent vanadium (50mg / L) and hexavalent chromium (50mg / L), and adjust the pH of the solution to 1.0 with concentrated sulfuric acid;

[0057] 2) Add 0.3 g of IRA-900 strongly basic anion exchange resin after pickling with 10% sulfuric acid solution to the solution, and the resin concentration is 0.6 g / L. Using magnetic stirring, the mixture was stirred at room temperature for 10 h at a speed of 300 rpm. During this process, the curve of the concentration of vanadium chromium in the solution is as follows Figure 4 As shown, the concentration of chromium gradually decreases, and the concentration of vanadium remains almost constant. It can be seen that chromium is continuously extracted by resin exchange in the form of negatively charged chromate or dichromate, while vanadium exists in the form of positively charged vanadyl cations. Without being exchanged and extracted by anion exchange resin. The main ion exchange rea...

Embodiment 2

[0075] 1) Take 500mL of a mixed solution containing pentavalent vanadium (1000mg / L) and hexavalent chromium (500mg / L), and adjust the pH of the solution to 1.0 with concentrated sulfuric acid;

[0076] 2) Add 2 g of IRA-900 strongly basic anion exchange resin after pickling with 10% sulfuric acid solution to the solution, and the resin concentration is 4 g / L. Using magnetic stirring, the mixture was stirred at room temperature for 10 h at a speed of 300 rpm. During this process, chromium in the solution is continuously extracted by resin exchange in the form of negatively charged chromate or dichromate, while vanadium is not exchanged and extracted by anion exchange resin because it exists in the form of positively charged vanadyl cation. The main ion exchange reactions that occur are as follows:

[0077] R-SO 4 +2HCrO 4 - →R-(HCrO 4 ) 2 +SO 4 2-

[0078] R-SO 4 +Cr 2 o 7 2- →R-Cr 2 o 7 +SO 4 2-

[0079] 3) separating the resin from the solution by filtering,...

Embodiment 3

[0086] This example is basically the same as Example 2, except that the pH of the mixed solution is adjusted to 1.4 with concentrated sulfuric acid for the first time, and the pH of the solution is adjusted to 4.0 with 10% sodium hydroxide solution for the second time. After extracting with strong basic anion exchange resin for the first time, the chromium in the solution is basically completely removed, and the concentration of vanadium basically does not change; after the second extraction with strong basic anion exchange resin, the concentration of vanadium in the final solution is reduced to 0.9mg / L or so, the chromium concentration is reduced to about 0.6mg / L. The effective separation of vanadium and chromium is achieved and a high recovery rate is achieved.

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Abstract

The invention discloses a method for efficiently separating vanadium and chromium based on pH regulation and control, and belongs to the field of waste water resource utilization. The method comprises the following steps that firstly, the pH value is adjusted to convert chromium in a solution containing vanadium and chromium into chromate or dichromate with negative electricity and convert vanadium into vanadyl ions with positive electricity, and anions in the solution are adsorbed by adopting resin; then the pH value is adjusted to convert the vanadyl ions in the solution into vanadate radicals or polyvanadate radicals with negative electricity, and the anions in the solution are adsorbed by adopting resin; and eluting is conducted to obtain a vanadium-containing solution or a chromium-containing solution. The method provided by the invention can realize effective separation of vanadium and chromium only through simple pH regulation and control, and has the advantages of high vanadium and chromium separation efficiency, high recovery rate, simple process and low cost.

Description

technical field [0001] The invention belongs to the field of waste water resource utilization, and in particular relates to a method for efficiently separating vanadium and chromium from a solution containing vanadium and chromium based on pH control. Background technique [0002] As a strategic metal resource, vanadium is widely used in metallurgy, chemical industry, national defense, aerospace and other fields. At present, the main raw material for the production of vanadium pentoxide in my country is the vanadium slag produced during the smelting process of vanadium-titanium magnetite. After the vanadium slag is roasted and leached, the vanadium element is converted into ions and enters the solution, and can be extracted by ammonium salt precipitation and other methods. However, since vanadium and chromium are two adjacent transition elements in the periodic table of elements, they often exist in natural minerals. When leaching, chromium will also enter the solution toge...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B3/44C22B3/24C22B34/32C22B34/22
CPCC22B7/006C22B34/32C22B34/22Y02P10/20
Inventor 张炜铭余航高亚娟汪林张延扬吕路潘丙才
Owner NANJING UNIV
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