Treatment method for two-step flotation of medical waste incineration fly ash

A technology for incinerating fly ash and medical waste, which is applied in the field of environmental pollution control. It can solve the problems that it is difficult to ensure that the leaching of heavy metals in residual ash reaches the standard, the separation and recovery of heavy metals cannot be achieved, and the effect of primary flotation decarbonization is affected, so as to achieve harmless The effects of efficient treatment and resource utilization, saving landfill space, and low cost

Active Publication Date: 2015-12-16
TIANJIN CHENGJIAN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the above method, an acid extractant needs to be added before the decarburization flotation in the first step to leach heavy metals, but too low a pH value will not only affect the decarburization effect of the first flotation, but also the Na added in the second flotation 2 S will react with H under strongly acidic conditions + The reaction produces toxic gas H 2 S, produces gas secondary pollution
If less acid extractant is added, it is difficult to ensure that the leaching toxicity of heavy metals in residual ash reaches the standard, and it is impossible to achieve the purpose of separation and recovery of Pb and Zn heavy metals in fly ash

Method used

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  • Treatment method for two-step flotation of medical waste incineration fly ash
  • Treatment method for two-step flotation of medical waste incineration fly ash
  • Treatment method for two-step flotation of medical waste incineration fly ash

Examples

Experimental program
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Effect test

Embodiment 1

[0020] See Table 1 for the thermal loss rate, heavy metals, dioxins and chlorine contents of a certain medical waste incineration fly ash.

[0021] Table 1 Thermal burn rate, heavy metal, dioxin and chlorine content of fly ash from medical waste incineration

[0022]

[0023] Adopt the method provided by the invention to process above-mentioned medical waste incineration fly ash, please refer to figure 1 , take the following steps:

[0024] 1) Decarbonization flotation

[0025] 1.1) Mix the incineration fly ash of medical waste with flotation agents and water to make mortar;

[0026] Add 200g of medical waste incineration fly ash and 4 liters of deionized water into the slurry mixing tank at the same time, and stir the mortar for 5 minutes to make the fly ash thoroughly wet. During this period, add 2.4 grams of kerosene and stir for several minutes to reconcile the slurry. During this time, 0.6 g of methyl isobutyl carbinol was added to the mortar and stirred for several...

Embodiment 2

[0041]The sample of fly ash from incineration of medical waste used is the same as in Example 1, the process flow for the fly ash from incineration of medical waste is the same as in Example 1, and the step 1) decarbonization flotation is also the same as in Example 1. The difference from Example 1 lies in step 2) and step 3), step 2): in the acid leaching procedure, nitric acid is added to the primary tailings to make the pH of the primary tailings=2, and then acid leaching, acid leaching After filtration, filter to obtain two products of residual ash and heavy metal waste liquid; step 3): add dodecylsulfuric acid (SDS) to the concentration of 0.2g / L in the heavy metal waste liquid, add methyl isobutyl at a concentration of 0.1% methyl alcohol (MIBC).

[0042] The above-mentioned enriched carbon products and residual ash were dehydrated and dried, and then tested and analyzed. The results are shown in Table 5. The dioxin content in the residual ash meets the dioxin limit requ...

Embodiment 3

[0051] The sample of fly ash from incineration of medical waste used is the same as in Example 1, the process flow for the fly ash from incineration of medical waste is the same as in Example 1, and the step 1) decarbonization flotation is also the same as in Example 1. The difference from Example 1 lies in step 2) and step 3), step 2): in the acid leaching procedure, nitric acid is added to the primary tailings to make the pH of the primary tailings=2, and then acid leaching, acid leaching After filtration, two products of residual ash and heavy metal waste liquid are obtained; step 3): add dodecyl sulfuric acid (SDS) according to the concentration of 0.30g / L in the heavy metal waste liquid, add methyl isobutylate according to the concentration of 0.1% methyl alcohol (MIBC).

[0052] The above-mentioned enriched carbon products and residual ash were dehydrated and dried, and then tested and analyzed. The results are shown in Table 8. The dioxin content in the residual ash mee...

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Abstract

The invention discloses a treatment method for two-step flotation of medical waste incineration fly ash. The method includes the following steps that (1) decarbonization flotation is conducted, the two products of enriched carbon and primary tail pulp are obtained, and the enriched carbon product is fed into a secondary combustion chamber of a waste incinerator for helping to combust; (2) acid leaching and filtering are carried out, inorganic acid is added into the primary tail pulp which is obtained in the first step to be filtered after acid leaching is completed, and the two products of residual ash and heavy metal waste liquor are obtained; the residual ash is directly conveyed to a municipal solid waste landfill to be subjected to secure landfill disposal or reuse; (3) ion flotation is performed, flotation reagents are added into the heavy metal waste liquor which is obtained in the second step for ion flotation, and the two products of heavy metal concentration foam and waste water are obtained; the heavy metal concentration foam is fed into a smelting plant to recycle heavy metal Pb and Zn, and after reaching the standard through neutralizing treatment, the waste water is discharged into a sewage system. The treatment method has the advantages of being easy to operate, low in cost, good in treatment effect, free of secondary pollution and the like.

Description

technical field [0001] The invention relates to a method for treating environmental pollution, in particular to a method for treating fly ash from incineration of medical waste. Background technique [0002] The fly ash produced by the incineration of medical waste is extremely harmful due to the enrichment of a considerable amount of toxic substances such as dioxins (PCDD / Fs) and heavy metals, and has been included in the "National Hazardous Waste List". At present, most medical waste incineration fly ash in China is only temporarily piled up or simply landfilled, which poses a huge safety hazard. Domestic and foreign researches on waste incineration fly ash treatment methods mainly focus on domestic waste incineration fly ash, mainly aiming at reducing the leachation of heavy metals and decomposing dioxins, forming cement solidification, chemical stabilization, solvent leaching, electrodialysis , Accelerated carbonation, medium and low temperature heat treatment, mechanoc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B03D1/00
Inventor 魏国侠刘汉桥张蕊徐仙臧丹丹孙磊
Owner TIANJIN CHENGJIAN UNIV
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