Method for treating stainless steel pickling waste liquor and recovering iron, chromium and nickel

A technology of pickling waste liquid and recovery method, which is applied in metallurgical wastewater treatment, chemical instruments and methods, water/sewage multi-stage treatment, etc., can solve the problems of low recovery rate and high treatment cost, and achieve low equipment cost and excellent treatment process Simple and easy to operate, the effect of objective economic benefits

Inactive Publication Date: 2015-07-29
NANYANG NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But its main problem is the low recovery rate and high processing cost

Method used

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  • Method for treating stainless steel pickling waste liquor and recovering iron, chromium and nickel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Get stainless steel pickling waste liquid 100mL and pour in 500mL beaker, the concentration of ferric ion is about 75mg / L after measuring, and chromium (III) ion concentration is 20mg / L, and nickel ion concentration is 18mg / L.

[0025] First use iron oxide scale to neutralize part of the acid in the waste liquid, after filtering, use 1 mol / L sodium hydroxide solution to adjust the pH value to 2.8, and obtain the preliminary separated Fe(OH) after filtering again 3 precipitation. In the filtrate, add ammonia solution and 1g of sodium sulfite with a molar ratio of 6:1 to nickel ions, adjust the pH value to 7.8, and obtain a solution containing Cr(OH) after filtration. 3 and a small amount of Fe(OH) 3 Filter residue 1 and filtrate 1 of nickel element. The filter residue 1 is adjusted to pH 12.2 through 1 mol / L sodium hydroxide solution, and the secondary separated Fe(OH) is obtained after precipitation and filtration. 3 Precipitate and chromium (III) ion filtrate, use 1...

Embodiment 2

[0027] Get stainless steel pickling waste liquid 100mL and pour in 500mL beaker, the concentration of ferric ion is about 79mg / L after measuring, chromium (III) ion concentration is 23mg / L, and nickel ion concentration is 19mg / L. The difference from Example 1 is that sodium bisulfite is used as a reducing agent, and the adjustment of pH value is different from Example 1 according to the dosage of ammonia and sodium hydroxide solution added.

[0028] First use iron oxide scale to neutralize part of the acid in the waste liquid, after filtering, use 1 mol / L sodium hydroxide solution to adjust the pH value to 2.5, and obtain the preliminary separated Fe(OH) after filtering again 3 precipitation. In the filtrate, add ammonia solution and 1.5g sodium bisulfite in a molar ratio of 6:1 to nickel ions, adjust the pH value to 8, and obtain a solution containing Cr(OH) after filtration. 3 and a small amount of Fe(OH) 3 Filter residue 1 and filtrate 1 of nickel element. The filter res...

Embodiment 3

[0030] Different from Example 1 is to adopt the stainless steel pickling liquid waste water that laboratory simulation is configured into, and wherein use raw material is Cr(NO 3 ) 3 , Ni(NO 3 ) 2 and Fe(NO 3 ) 3 , take an appropriate amount of weight and add deionized water and hydrochloric acid to adjust the pH value to 2.2, and the concentration of chromium and nickel ions in the solution is 50mg / L, and the concentration of iron ions is 100mg / L. Take 100mL of the prepared solution and pour it into a 500mL beaker.

[0031] Directly use 1 mol / L sodium hydroxide solution to adjust the pH value to 2.5, and obtain the preliminary separated Fe(OH) after filtration 3precipitation. In the filtrate, add ammonia solution and 3g of sodium sulfite in a molar ratio of 6:1 to nickel ions, adjust the pH to 7.8, and obtain a solution containing Cr(OH) after filtration. 3 and a small amount of Fe(OH) 3 Filter residue 1 and filtrate 1 of nickel element. The filter residue 1 is adjus...

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Abstract

The invention discloses a method for treating stainless steel pickling waste liquor and recovering iron, chromium and nickel. According to the method, a sodium hydroxide solution is adopted to control the pH of the stainless steel pickling waste liquor to achieve the purpose of recovery of iron, chromium and nickel through fractional precipitation. Because pH ranges of deposition of the iron, chromium and nickel elements are overlapped, part of iron oxide-hydroxide is precipitated firstly in a separation and recovery process, residual iron and chromium elements are co-precipitated out, and then chromium is precipitated and dissolved under the strong alkaline condition to realize final separation of iron and chromium. Due to presence of ammonia water and a reducing agent, the nickel element exists in the form of ions or a nickel ammine complex, is dissolved in the waste liquor, and finally reacts with a sulfide to precipitate NiS. The method has the characteristics of low cost, easiness in control, high separation and recovery rate of the iron, chromium and nickel elements and the like. The method can treat the stainless steel pickling waste liquor effectively, and the natural environment cannot be polluted after emission; the recovered metal elements have the recycling economic benefits, and the method has high application value and important technological innovation meaning.

Description

technical field [0001] The invention belongs to the technical field of environmental protection for the recovery and reuse of industrial waste water, and in particular relates to the treatment of stainless steel pickling waste liquid and the recovery method of iron, chromium and nickel. Background technique [0002] my country is currently a big producer and consumer of stainless steel profiles, and the production and demand for industrial stainless steel continue to increase. In the production process of stainless steel, a metal oxide layer will be formed on the surface of the material after annealing. In order to remove the metal oxide layer, strengthen the surface of the stainless steel, and improve the corrosion resistance of the stainless steel, nitric acid, hydrofluoric acid or mixed acids are usually used to treat the stainless steel. The surface of the product is cleaned and oxidized. A large amount of iron ions, chromium ions, nickel ions, manganese ions and fluori...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B23/00C22B34/32C02F9/04C02F103/16C02F101/20C02F101/22
CPCY02P10/20
Inventor 高远飞张晓莉谢明森朱原原谢海泉
Owner NANYANG NORMAL UNIV
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