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Method for treating sludge containing trivalent chromium and recovering heavy metal

A technology of heavy metals and trivalent chromium, applied in sludge treatment, non-metallic elements, sustainable waste treatment, etc., can solve problems such as increased difficulty, difficult separation, complex acid leaching solution components, etc., to eliminate hidden dangers of pollution, The effect of high purity

Active Publication Date: 2013-04-03
武汉巍川环保科技有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the composition of the acid leaching solution is complex, and the chromium mud contains a large amount of acid-soluble substances, such as iron, zinc, nickel, copper, aluminum, silicate, phosphate, etc.
Acid dissolution makes these ions enter the acid immersion solution, and further separation is more difficult. In addition, alkali-dissolution oxidation converts low-toxic trivalent chromium into highly toxic hexavalent chromium, and the difficulty of meeting emission standards is greatly increased.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] A method for treating sludge containing trivalent chromium and recovering heavy metals, comprising the steps of:

[0039]1. Analysis of components and content in chromium-containing sludge (mass percentage): The chromium-containing sludge produced by an electroplating enterprise has a water content of 60% and a dry basis of 40%; the dry basis is analyzed by X-fluorescence emission spectroscopy. Contains 11.7% by weight of silicate, 9% of phosphate, 11.3% of sulfate, 1.7% of iron hydroxide, 3.7% of aluminum hydroxide, 47.4% of chromium hydroxide, 0.1% of copper oxide, 11.5% of zinc oxide, oxide 0.05% nickel, 0.7% calcium hydroxide, 0.3% magnesium hydroxide and a small amount of potassium salt, sodium salt, etc.;

[0040] 2. Dilute the chromium-containing sludge: Weigh 100kg of chromium-containing sludge, add 70kg of water, stir and beat in the mixer, and make the chromium-containing sludge slurry after the chromium-containing sludge is evenly dispersed;

[0041] 3. Ammo...

Embodiment 2

[0050] A method for treating sludge containing trivalent chromium and recovering heavy metals, comprising the steps of:

[0051] 1. Analysis of the component content in the chromium-containing sludge: the chromium-containing sludge produced by a steel company has a water content of 50wt% and a dry basis of 50wt%; the dry basis is analyzed by X-ray fluorescence spectrometer and contains silicate by weight percentage 19.5%, 4.5% phosphate, 36.7% sulfate, 0.7% iron oxide, 2.9% aluminum oxide, 3.4% chromium oxide, 1.6% zinc oxide, 29.3% calcium oxide, 0.4% magnesium hydroxide and a small amount of potassium salt and sodium salt etc.; 2. Dilute chromium-containing sludge: Weigh 100kg of chromium-containing sludge, add 100kg of water, stir and beat in a mixer, and make chromium-containing sludge slurry after the chromium-containing sludge is evenly dispersed;

[0052] 3. Ammonium salt and ammonia water treatment: Add 20 kg of industrial ammonium sulfate and 5 kg of industrial ammoni...

Embodiment 3

[0061] The difference with embodiment 1 is:

[0062] Step 2, add water 1000 kg,; Step 3 adds industrial ammonium chloride 900kg, industrial ammoniacal liquor, 1000kg; The concentration of sodium hydroxide aqueous solution is 1mol / L in the step 4, and the weight ratio of filter residue and sodium hydroxide aqueous solution is 1:10, The stirring time is 10 hours; the concentration of hydrochloric acid in step 5 is 10 mol / L, and the weight ratio of filter residue to acid solution is 1:10. The discharged waste residue and waste water were analyzed by 721 spectrophotometer to check that the chromium content was 0.02μg / ml and 0.02μg / ml.

[0063] The slurry obtained in Example 3 has low concentration and low viscosity, which is convenient for stirring and dispersing, requires little torque for the equipment, and is convenient for equipment selection. Gained each product all can reach the effect described in embodiment 1. But because the input of each raw material in this case of em...

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Abstract

The invention discloses a method for treating sludge containing trivalent chromium and recovering heavy metal. The method comprises the following steps: analyzing the content of components in sludge containing chromium to dilute the sludge containing chromium; and treating the sludge containing chromium by ammonium salt, ammonia water, alkali and acid to obtain pigment grade chromium oxide, single metal or other products. The method is applied to the disposal and recovery process of the sludge containing chromium generated in the industries, such as steel, electroplating and tanning to achieve a good pollution control and resource recovery effect.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for treating sludge containing trivalent chromium and recovering heavy metals. Background technique [0002] A large amount of chromium-containing wastewater and sludge will be produced in the production of steel rolling, electroplating, and tanning. The treatment process of chromium-containing wastewater is relatively mature, but there is no effective treatment method for chromium-containing sludge. Large-scale stacking will not only cause land It will also cause certain pollution to the environment, and it is also a waste that the chromium resources in the chromium-containing sludge cannot be fully utilized. [0003] The patent number is [87105027.7] titled "Method for Treating Trivalent Chromium-Containing Sludge", which uses a sulfuric acid medium solution to convert trivalent chromium sludge into sulfate precipitation, and the precipitat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/00C02F1/52C22B7/00C22B34/32C01B33/20C01G9/06C01F11/46C04B7/24C04B18/30
CPCY02P10/20Y02P40/10Y02W30/91
Inventor 宋乐山周冲张译
Owner 武汉巍川环保科技有限责任公司
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