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A two-step flotation treatment method for medical waste incineration fly ash

A technology for incinerating fly ash and medical waste, which is applied in the field of environmental pollution control, 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: 2018-03-09
TIANJIN CHENGJIAN UNIV
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  • Summary
  • 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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  • A two-step flotation treatment method for medical waste incineration fly ash
  • A two-step flotation treatment method for medical waste incineration fly ash
  • A two-step flotation treatment method for 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 two-step flotation treatment method for incineration fly ash of medical waste. The following steps are adopted: 1) decarbonization flotation to obtain two products of enriched carbon and primary tailings, and sending the enriched carbon product into garbage Combustion in the second combustion chamber of the incinerator; 2) acid leaching filtration: add inorganic acid to the primary tailings obtained in step 1) to carry out acid leaching and then filter to obtain two products: residual ash and heavy metal waste liquid; the residual ash is directly sent to domestic garbage Landfill for safe landfill disposal or reuse; 3) Ion flotation: Add flotation agents to the heavy metal waste liquid obtained in step 2) to carry out ion flotation to obtain two products of heavy metal concentrated foam and waste water; concentrate the heavy metal The foam is sent to the smelter to recover heavy metals Pb and Zn, and the wastewater is neutralized and discharged into the sewage system after reaching the standard. The invention has the advantages of simple operation, low cost, good treatment effect and no secondary pollution.

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 Patents(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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