A method for harmless treatment of arsenic-containing sludge

A technology for harmless treatment of arsenic sludge, applied in oxidation treatment of sludge, chemical instruments and methods, sludge treatment, etc., can solve the problem of low solidification rate, achieve low roasting temperature, low temperature, and improve solidification effect Effect

Active Publication Date: 2017-05-24
KUNMING METALLURGY INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The commonly used and feasible method for arsenic-containing sludge disposal is solidification and stabilization treatment. The most commonly used solidification agents are lime, fly ash, etc. Common solidification treatment has disadvantages such as low solidification rate. How to further improve the solidification effect is still under further study

Method used

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  • A method for harmless treatment of arsenic-containing sludge

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Experimental program
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Effect test

Embodiment 1

[0041] (1) Sludge pre-treatment: first dehydrate the arsenic-containing sludge to make the moisture content of the arsenic-containing sludge 60%.

[0042] (2) Material mixing: Mix 500g of arsenic-containing sludge in step (1) with 25g of fly ash evenly, and then make particles with a diameter of 0.5-1.5cm.

[0043] (3) Sludge preheating treatment: Under normal pressure, use microwaves to pretreat and heat the sludge particles treated in step (2) for 5 minutes, and the heating temperature is 100°C.

[0044] (4) One-stage microwave oxidation roasting: Under normal pressure, control the material treated in step (3) to 300°C for 30 minutes, and feed 10% oxygen. This process oxidizes trivalent arsenic in the sludge into pentavalent arsenic.

[0045] (5) Two-stage microwave oxidation roasting: Under normal pressure, 10% oxygen is continuously introduced, and the material treated in step (4) is brought to a temperature of 500°C and kept for 40 minutes. for further oxidative decompo...

Embodiment 2

[0048] (1) Sludge pretreatment: first, dehydrate the arsenic-containing sludge to make the moisture content of the arsenic-containing sludge 60-70%.

[0049] (2) Material mixing: Mix 500g of arsenic-containing sludge and 50g of fly ash in step (1) evenly, and then make particles with a diameter of 0.5-1.5cm.

[0050] (3) Sludge preheating treatment: Under normal pressure, use microwaves to pretreat and heat the sludge particles treated in step (2) for 5 minutes, and the heating temperature is 100°C.

[0051] (4) One-stage microwave oxidation roasting: Under normal pressure, control the material treated in step (3) to 350°C for 25 minutes, and feed 20% oxygen. This process oxidizes trivalent arsenic in the sludge into pentavalent arsenic.

[0052] (5) Two-stage microwave oxidation roasting: Under normal pressure, continuously feed 20% oxygen, bring the material treated in step (4) to a temperature of 550°C, and keep it warm for 35 minutes. for further oxidative decomposition. ...

Embodiment 3

[0055] (1) Sludge pretreatment: first, dehydrate the arsenic-containing sludge to make the moisture content of the arsenic-containing sludge 60-70%.

[0056] (2) Material mixing: Mix 500g of arsenic-containing sludge in step (1) with 100g of fly ash evenly, and then make particles with a diameter of 0.5-1.5cm.

[0057] (3) Sludge preheating treatment: Under normal pressure, use microwaves to pretreat and heat the sludge particles treated in step (2) for 5 minutes, and the heating temperature is 100°C.

[0058] (4) One-stage microwave oxidation roasting: Under normal pressure, control the material treated in step (3) to 400 ° C for 20 minutes, and feed 30% oxygen. This process oxidizes trivalent arsenic in the sludge into pentavalent arsenic.

[0059] (5) Two-stage microwave oxidation roasting: Under normal pressure, continuously feed 30% oxygen, bring the material treated in step (4) to a temperature of 600°C, and keep it warm for 30 minutes. for further oxidative decomposit...

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Abstract

The invention discloses a method for harmless treatment on arsenic-containing sludge. The method comprises pre-treatment, first-stage microwave oxidizing roasting and second-stage microwave oxidizing roasting. Concretely, the method comprises carrying out dehydration on arsenic-containing sludge until water content is in a range of 60-70%, adding a curing agent into the arsenic-containing sludge, carrying out mixing to obtain a uniform mixture, processing the mixture to obtain particles, heating the particles at a temperature of 90-110 DEG C for 4-6min, carrying out microwave heating at a temperature of 300-500 DEG C, feeding oxygen into the particles, carrying out roasting for 10-30min so that trivalent arsenic in the sludge is oxidized to form pentavalent arsenic, continuously feeding oxygen into the sludge, carrying out microwave heating at a temperature of 500-700 DEG C, and carrying out heat preservation for 20-40min so that trivalent arsenic is further oxidized and organic arsenic obtained by oxidizing roasting cracking in the step C is further oxidized and decomposed. The arsenic-containing sludge is subjected to microwave catalytic oxidation so that curing effects are improved, process is simple, roasting time is short, a temperature is low, no secondary pollution is produced in the whole process, arsenic-containing sludge stacking-caused environmental pollution problem is solved, and good economic benefits, environmental benefits and social benefits are obtained.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for harmlessly treating arsenic-containing sludge. Background technique [0002] With the development of economy and society, the sources of arsenic-containing sludge have become more and more complex and extensive, such as non-ferrous metal smelting, chemical raw material production, chemical manufacturing and other industries. A large amount of arsenic-containing sludge is produced, and the arsenic in the sludge has the characteristics of long residual time, strong concealment and high toxicity. If not handled properly, the arsenic in the sludge can have an impact on the environment through soil, air, water and other media, especially the impact on groundwater. Once polluted, the consequences will be very serious. [0003] Arsenic-containing sludge is mainly produced in the treatment process of wastewater discharged from non-ferrous metal ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F11/00C02F11/06
Inventor 欧根能陶辉旺姜永利刘维维陈华君李啸寅丁怡然王少龙栾景丽杨勇熊国焕
Owner KUNMING METALLURGY INST
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