Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Step-by-step flotation detoxification method for fly ash of medical waste incineration

A technology for incinerating fly ash and medical waste, which is applied in the field of environmental pollution control. It can solve the problems of waste liquid mixed with residual ash, long precipitation time, complex process, etc., and achieve the effects of reduced treatment costs, simple operation, and low cost

Active Publication Date: 2017-07-04
TIANJIN CHENGJIAN UNIV
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method of sedimentation-filtration to separate heavy metals tends to have some shortcomings: for example, the precipitation time is too long, resulting in incomplete filtration, resulting in the waste liquid containing high concentrations of heavy metals mixed into the residual ash, which makes the heavy metals in the residual ash relatively high, and the residual ash must be processed before final disposal. May also need washing or stabilization, complicated process, etc.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Step-by-step flotation detoxification method for fly ash of medical waste incineration
  • Step-by-step flotation detoxification method for fly ash of medical waste incineration
  • Step-by-step flotation detoxification method for fly ash of medical waste incineration

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] See Table 1 for the thermal loss rate, heavy metals, dioxins and chlorine contents of a certain medical waste incineration fly ash. Add 200g of medical waste incineration fly ash and 4 liters of deionized water into the slurry mixing tank at the same time, stir the mortar for 5 minutes to make the fly ash thoroughly wet, during this period, add hydrochloric acid to the mortar to make the pH of the mortar = 6, and add 2.4 grams The kerosene was stirred for several minutes to temper the slurry, during which time 0.6 grams of methyl isobutyl carbinol was added to the mortar and stirred for several minutes to temper the slurry.

[0016] Table 1 Thermal burn rate, heavy metal, dioxin and chlorine content of fly ash from medical waste incineration

[0017]

[0018] The above-mentioned slurry is sent to the flotation column for flotation for the first step of flotation. The hydrophobic carbon components (activated carbon and residual carbon) and dioxin in the slurry are att...

Embodiment 2

[0028] The medical waste incineration fly ash sample used is the same as that in Example 1, nitric acid is added to the mortar in the first step of flotation to make the pH of the mortar=5, and in the second step of flotation, press S 2- The number of moles is the number of moles of all heavy metal ions in the first tailing slurry and adding Na 2 S, other added flotation agents and operating parameters are the same as in Example 1.

[0029] The flotation separation product was analyzed after dehydration and drying, and the results are shown in Table 5. The dioxin content in the residual ash met the dioxin limit required by GB16889-2008 (<3ng TEQ / g). At the same time, the dried residual ash was tested for the leaching concentration of heavy metals according to HJ / T300. The test results are shown in Table 6. The harmful concentration in the leaching solution is lower than the concentration limit of heavy metal pollutants in GB16889-2008, indicating that the residual ash can be d...

Embodiment 3

[0038] The medical waste incineration fly ash sample that adopts is identical with embodiment 1, in the first step flotation mortar pH=7, press S in the second step flotation 2- The number of moles is 3 times of the number of moles of all heavy metal ions in the first tailings and add Na 2 S, other added flotation agents and operating parameters are the same as in Example 1.

[0039] According to the above conditions, the flotation separation products (enriched carbon, residual ash, precipitated salt) were analyzed after dehydration and drying. The results are shown in Table 8. The dioxin content in the residual ash meets the dioxin limit required by GB16889-2008 (<3ngTEQ / g). At the same time, the dried residual ash was tested for heavy metal leaching concentration according to HJ / T300. The test results are shown in Table 9. The harmful concentration in the leaching solution is lower than the concentration limit of heavy metal pollutants in GB16889-2008, indicating that the r...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a sub-step flotation and detoxification method for incineration fly ash of medical garbage. The sub-step flotation and detoxification method is characterized in that coseparation of dioxin and a carbon component is realized by first-step flotation, so that the toxicity of organic pollutants including the dioxin and the like in the fly ash is reduced; meanwhile, soluble heavy metal is eluted; second-step flotation of tail slurry is subjected to a sulfide precipitation flotation method and heavy metal including Pb, Zn and the like is removed and recycled, so that the harms of the heavy metal are eliminated. Separated final products mainly comprise enriched carbon, residual ash, heavy metal sediment salt and the like, wherein the enriched carbon rich in the dioxin is conveyed into a garbage incinerator secondary incineration chamber to be incinerated, so that the high-temperature decomposition of the dioxin is realized by a low cost; the volume and the toxicity of the residual ash are greatly reduced and the residual ash is directly conveyed into a municipal solid waste landfill to be safely treated or reutilized, so that the subsequent treatment cost is greatly reduced; the heavy metal in the fly ash is leached with an acid and vulcanized and then is precipitated, floated and recycled, so that a plurality of purposes are realized. The method can realize harmless treatment and resource utilization of the incineration fly ash of the medical garbage under environment-friendly and low-cost conditions.

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] Fly ash produced by 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". Most domestic medical waste incineration fly ash is only temporarily piled up or simply landfilled, which poses a huge safety hazard. For this reason, the national standard GB16889-2008 provides a temporary disposal method, which allows it to be disposed of in domestic waste landfills after treatment. This expedient measure cannot fundamentally eliminate the environmental pollution caused by fly ash incineration of medical waste . There are obvious differences between medical waste incineration fly ash and domestic waste incinera...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): B03D1/00
Inventor 魏国侠刘汉桥周建国武振华孙磊
Owner TIANJIN CHENGJIAN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Eureka Blog
Learn More
PatSnap group products