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Method for reclaiming heavy metal in fly ash or secondary fly ash

A secondary fly ash and recovery method technology, applied in the direction of improving process efficiency, can solve the problems of high investment and operating costs, low comprehensive benefits, long process, etc., to achieve no secondary pollution, reduce burden, and flue gas volume small effect

Inactive Publication Date: 2007-05-23
CHINESE RES ACAD OF ENVIRONMENTAL SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still many problems in this method, such as the waste water and waste acid and alkali liquid produced in the extraction process must be strictly treated
Therefore, it has the disadvantages of long process, high investment and operating costs, easy to produce serious secondary pollution, and low comprehensive benefits.

Method used

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  • Method for reclaiming heavy metal in fly ash or secondary fly ash
  • Method for reclaiming heavy metal in fly ash or secondary fly ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Please refer to Figure 1. This embodiment uses a three-circuit high-temperature atmosphere electric furnace device, which has a high-temperature zone, a medium-temperature zone, and a low-temperature zone. Several medium- and low-temperature zones can also be set up according to the needs of the fly ash to be processed.

[0019] According to the composition of heavy metal compounds in the fly ash to be treated, the temperature in the high temperature zone of the three-circuit high-temperature atmosphere electric furnace is raised to the melting point of the fly ash, and the heavy metals in the fly ash are the oxidation of lead, chromium, cadmium, aluminum, zinc and copper. The melting point is 500-1300°C, and the freezing point is higher than 600°C and 200°C respectively. The high temperature zone 4 is set at 1300°C, the medium temperature zone 7 is set at 600°C, and the low temperature zone is set at 600°C. 9 is set to 100°C, and then the corundum ark 6 loaded with fly ...

Embodiment 2

[0022] Please refer to Fig. 1, what this embodiment adopts is that the three-circuit high-temperature atmosphere electric furnace device is the same as embodiment 1.

[0023] According to the composition of the heavy metal compound in the secondary fly ash to be treated, the temperature in the high temperature zone of the three-circuit high-temperature atmosphere electric furnace is raised to a temperature above the melting point of the fly ash. The heavy metals in the fly ash are lead, chromium, cadmium, aluminum and zinc. And copper oxide and chloride, its melting and boiling point is 500-1300 ℃, and the freezing point is higher than 600 ℃ and 200 ℃ respectively, then the high temperature zone 4 is set to 1100 ℃, the middle temperature zone 7 is set to 400 ℃, and the low temperature zone 9 Set it to 50°C, then put the corundum ark 6 loaded with secondary fly ash into the high-temperature furnace 5, close the furnace door, and feed oxygen (also can be air, oxygen, nitrogen, hy...

Embodiment 3

[0025] Please refer to Fig. 1, what this embodiment adopts is that the three-circuit high-temperature atmosphere electric furnace device is the same as embodiment 1.

[0026] Peel and crush the waste batteries to 1-50 mesh, then put them into the corundum ark and send them into the furnace. At this time, set the temperature of the high-temperature zone 4 of the three-circuit high-temperature atmosphere electric furnace to 50-70°C, temporarily set the temperature in the middle-temperature zone 7 and low-temperature zone 9 to 0°C, and then gradually increase the temperature and introduce a non-oxidizing atmosphere with a gas flow rate of 200L / h , to collect mercury. When the temperature in the high temperature zone 4 rises to 400°C, take out the medium and low temperature collection systems 9 and 10, replace a set of collection systems, and gradually increase the temperature in the medium and low temperature zones, and set the distribution to 400°C and 100°C. At the same time, ...

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Abstract

The invention discloses a method for recovering heavy metals from fly ash or secondary fly ash with multi-circuit high temperature air electric furnace. The furnace has one high temperature part, at least one middle temperature part, and at least one low temperature part. The temperature in high temperature part is set as the melting point of the heavy metal, and the temperature in middle and low temperature parts are set as congelation point or solidifying point of the heavy metal. The fly ash or secondary fly ash is put in high temperature part, introducing air, the heavy metal in the ash is melted to mixed composition volatile, which is introduced into parts of middle and low temperature by the air, and then different heavy metals in the ash solidify in middle temperature part and low temperature part respectively. The invention has the advantages of low investment, simple equipments and high metal recovery rate.

Description

technical field [0001] The invention relates to the harmless treatment and recycling technology of heavy metals in fly ash, in particular to a method for recovering heavy metals in fly ash or secondary fly ash. Background technique [0002] At present, incineration is often used to deal with garbage, and the incineration of garbage leads to a huge increase in the output of fly ash. Fly ash contains a large amount of heavy metals and harmful substances. If it is directly landfilled without special treatment, the heavy metals in the fly ash will seep out in large quantities under the acidic conditions of the landfill, pollute the groundwater, soil and even the air, and pass through the heavy metals in animals and plants. If the fly ash is directly used as a raw material for other products without special treatment, heavy metals and harmful substances in the fly ash are likely to be leached during use, directly or indirectly polluting the environment and human health. In addit...

Claims

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Application Information

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IPC IPC(8): C22B7/02C22B9/02
CPCY02P10/20
Inventor 王琪田书磊金晶
Owner CHINESE RES ACAD OF ENVIRONMENTAL SCI
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