A kind of method for removing heavy metal in fly ash

A technology for fly ash and heavy metals, applied in the field of coal chemical industry, can solve the problems of poor economic benefit, secondary pollution and high cost

Active Publication Date: 2022-07-26
杭州石炭纪环保科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods all treat heavy metal elements in solid waste by leaching or digestion with additional biochemical materials, resulting in a large amount of treated wastewater, which is easy to cause secondary pollution, and the cost is high and the economic benefit is poor.

Method used

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  • A kind of method for removing heavy metal in fly ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] The fly ash is firstly removed from the iron element by the iron remover, and then 0.02% triethanolamine is added and stirred for 15 minutes, and then the powder is dispersed by vibration. The dispersed powder is heated to 150°C in a heater, and then conveyed to an electrostatic separator by pneumatic force to maintain a flow rate of 1m / s and a flue gas concentration of 90g / Nm 3 . In the electrostatic separator, under the action of 7500V high voltage, the coarse particles in the fly ash are enriched on the electrode plate, and the rapping force is 200g every 60min. The two poles of the electrodes were ripped in turn, and the rapping time was 2 min each time.

[0053] The fly ash in the flue gas enters the centrifugal separator. At this time, the intake air velocity is 1.5m / s, the turbine speed in the primary separation chamber is 1000rpm, and the secondary air component is 1500m 3 / h. After passing through the two-stage separation system, the fine particles leave the...

Embodiment 2

[0056] The fly ash is firstly removed from the iron element through the iron remover, and then 0.05% glycerol is added and stirred for 12 minutes, and then the powder is dispersed by vibration. The dispersed powder is heated to 150°C in a heater, and then transported to an electrostatic separator by pneumatic force to maintain a flow rate of 1.2m / s and a flue gas concentration of 110g / Nm 3 . In the electrostatic separator, under the action of 8500V high voltage, the coarse particles in the fly ash are enriched on the electrode plate, and the rapping force is 360g every 75min. The two poles of the electrode were ripped in turn, and the rapping time was 3.5 min each time.

[0057] The fly ash in the flue gas enters the centrifugal separator. At this time, the intake air velocity is 1.5m / s, the turbine speed in the primary separation chamber is 3200rpm, and the secondary air component is 2000m 3 / h. After passing through the two-stage separation system, the fine particles leav...

Embodiment 3

[0060] The fly ash was firstly removed from the iron element by the iron remover, and then 0.01% stearic acid was added and stirred for 15 minutes, and then the powder was dispersed by vibration. The dispersed powder is heated to 120°C in a heater, and then conveyed to an electrostatic separator by pneumatic force to maintain a flow rate of 1.3m / s and a flue gas concentration of 130g / Nm 3 . In the electrostatic separator, under the action of 8000V high voltage, the coarse particles in the fly ash are enriched on the electrode plate, and the rapping force is 440g every 90min. The two poles of the electrodes were ripped in turn, and the rapping time was 5 min each time.

[0061]The fly ash in the flue gas enters the centrifugal separator. At this time, the intake air velocity is 1.8m / s, the turbine speed in the primary separation chamber is 3200rpm, and the secondary air component is 3500m 3 / h. After passing through the two-stage separation system, the fine particles leave t...

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Abstract

The invention provides a method for removing heavy metals from fly ash, which comprises the following steps: adding a dispersant after magnetic separation of the fly ash and removing iron, stirring evenly, and then dispersing by vibration, performing electrostatic separation, and sieving to obtain a particle size The fly ash particles between 0.1 and 20 μm; the fly ash particles with a particle size between 0.1 and 20 μm obtained by screening enter the first classification chamber for a centrifugal separation, and the large particles settle into the second classification chamber. Secondary air is introduced into the second grading chamber, so that the small particles in it float up into the first grading chamber, and fly ash particles with an average particle size of less than 10 μm are screened out. After the fly ash goes through the steps of iron removal, dispersing, electrostatic separation and centrifugal separation in sequence, the fine particles are completely separated out, and this part of the fine particles is enriched with a large amount of heavy metal elements, so the present invention can effectively reduce dust. Content of heavy metal elements in coal ash.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, and in particular relates to a method for removing heavy metals in fly ash. Background technique [0002] China is the largest coal producer and consumer in the world, producing about 580 million tons of fly ash every year, and the current stockpile has reached 2.5 billion tons. The accumulation of a large amount of fly ash will cause harm to the ecological environment and human health. Therefore, the comprehensive utilization of bulk fly ash is the focus of green and sustainable development. However, the raw coal itself contains heavy metal elements, some of which will be enriched in the fly ash during the coal combustion process, which not only restricts the application of fly ash in water and soil, but also is not compatible with the natural environment due to the accumulation and migration characteristics of heavy metal elements. closely related to human health. Therefore, th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B03C1/30
CPCB03C1/30
Inventor 陈良
Owner 杭州石炭纪环保科技有限公司
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