Method for chromium residue innocent treatment by utilizing rubbish percolate

A technology for landfill leachate and harmless treatment, applied in the removal of solid waste, etc., can solve the problems of large water quality changes, high ammonia nitrogen content, high cost, etc., and achieve the effect of reducing raw material costs, complex components, and investment costs

Inactive Publication Date: 2010-10-27
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 2. CODcr and BOD 5 High concentration
[0006] 3. The content of ammonia nitrogen is high, and it will increase with the extension of landfill time, up to 1700mg / L
[0007] 4. Water quality changes greatly
After the lake sediment and chromium slag are evenly mixed, they are placed in a microwave field for oxidation-reduction reaction, and the hexavalent chromium in the chromium slag is reduced to trivalent chromium, which can basically detoxify the chromium slag; The difficulty of large-scale application is not trivial

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Dry the chromium slag, grind it to a 2mm sieve, and mix it with landfill leachate at a mixing ratio of landfill leachate COD Cr The mass ratio of the total amount to the chromium slag is 0.2. The mixture is fed into the inner cylinder of the externally heated rotary kiln through a screw feeder for preheating and drying, and the residence time of the mixture in the inner cylinder of the externally heated rotary kiln is 0.5 hour, so that the moisture content of the dried mixture is lower than 5%.

[0031] The reduction combustion furnace uses natural gas as fuel, and the air excess coefficient in the reduction combustion furnace is controlled to be 1. The temperature of the generated hot gas is about 500°C, and the oxygen content is less than 0.5%. The generated high-temperature hot gas is introduced into the internal heating type pyrolysis furnace.

[0032] Send the mixture preheated by the external heating rotary furnace into the internal heating pyrolysis furnace, and ...

Embodiment 2

[0037] Dry the chromium slag, grind it to a 2mm sieve, and mix it with landfill leachate at a mixing ratio of landfill leachate COD Cr The mass ratio of the total amount to the chromium slag is 0.5. The mixture is fed into the inner cylinder of the externally heated rotary kiln through a screw feeder for preheating and drying, and the residence time of the mixture in the inner cylinder of the externally heated rotary kiln is 1 hour, so that the moisture content of the dried mixture is lower than 5%.

[0038] The reduction combustion furnace uses natural gas as fuel, and the Uno air excess coefficient in the reduction combustion furnace is controlled to be 0.8. The temperature of the generated hot gas is about 300°C, and the oxygen content is less than 0.5%. The generated high-temperature hot gas is introduced into the internal heating type pyrolysis furnace.

[0039] Send the mixture preheated by the external heating rotary furnace into the internal heating pyrolysis furnace, ...

Embodiment 3

[0044] Dry the chromium slag, grind it to a 2mm sieve, and mix it with landfill leachate at a mixing ratio of landfill leachate COD Cr The mass ratio of the total amount to the chromium slag is 0.1. The mixture is fed into the inner cylinder of the externally heated rotary kiln through a screw feeder for preheating and drying, and the residence time of the mixture in the inner cylinder of the externally heated rotary kiln is 0.5 hour, so that the moisture content of the dried mixture is lower than 5%.

[0045] The reduction combustion furnace uses natural gas as fuel, and the Uno air excess coefficient in the reduction combustion furnace is controlled to be 0.8. The temperature of the generated hot gas is about 900°C, and the oxygen content is less than 0.5%. The generated high-temperature hot gas is introduced into the internal heating type pyrolysis furnace.

[0046] Send the mixture preheated by the external heating rotary furnace into the internal heating pyrolysis furnace...

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Abstract

The invention relates to a method for chromium residue innocent treatment by utilizing rubbish percolate. Rubbish percolate is utilized as additive, chromium residue and the rubbish percolate are mixed in certain ratio, the mixture is fed into an externally heated rotary furnace to be dried and then is fed into an internally heated pyrolyzing furnace for carrying out pyrolysis reaction, high temperature reducing gas in the internally heated pyrolyzing furnace is led in from a reducing combustion furnace, and pyrolysis product after reductive treatment is discharged after water quenching. The tail gas of the internally heated pyrolyzing furnace is mixed with air by virtue of a dilution tank and then enters into the externally heated rotary furnace to directly dry the mixture of rubbish percolate and chromium residue. The invention has simple technological flow, low investment cost and available additive raw material, and reaction effect is satisfactory, and optimal utilization of rubbish percolate value is effectively realized while detoxifying chromium residue, thus having obvious environmental protection benefit and economic benefit.

Description

technical field [0001] The invention relates to a method for harmless treatment of chromium slag, in particular to a method for harmless treatment of chromium slag by utilizing landfill leachate. It belongs to the category of "three wastes" treatment in the field of environmental protection. Background technique [0002] Landfill leachate is a secondary pollutant produced during the garbage disposal process. Landfill leachate is the sewage leached out due to fermentation, rainwater washing, and surface water and groundwater immersion during the process of garbage stacking and landfilling. There are four main sources: the water contained in the garbage itself, the water produced by the biochemical reaction of garbage, the reverse osmosis of underground diving, and atmospheric precipitation. Among them, atmospheric precipitation is concentrated, short-term and repetitive, accounting for most of the total leachate. [0003] Landfill leachate is a kind of high-concentration org...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B09B3/00
Inventor 何圣兵张大磊杨峰峰戴鼎立李亚红
Owner SHANGHAI JIAO TONG UNIV
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