Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for digesting free calcium oxide in steelmaking dedusting ash

A technology of free calcium oxide and digestion container, which is applied in the field of solid waste treatment and can solve problems such as potential safety hazards, long time required, iron oxidation, etc.

Active Publication Date: 2020-10-30
河北蓝海智投环保科技有限公司
View PDF4 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems that it takes a long time to digest the steelmaking dust removal ash, there are potential safety hazards in high temperature and high pressure, the iron in the steelmaking dust removal dust will be oxidized, and the obtained product has uneven particle size, the invention provides a digestion method for free calcium oxide in the steelmaking dust removal dust

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
  • Method for digesting free calcium oxide in steelmaking dedusting ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The present embodiment provides a kind of digestion method of free calcium oxide in steelmaking dedusting ash, and this digestion method comprises the following steps:

[0028] S1. Put the steelmaking dust removal ash in the digestion container; inject carbon dioxide into the digestion container after vacuuming, and repeat the operations of vacuuming and injecting carbon dioxide until the oxygen content in the gas in the digestion container is <1% v / v;

[0029] S2. Inject saturated water vapor into the digestion vessel and adjust the concentration of carbon dioxide so that the molar weight of water molecules in the saturated water vapor is 65% of the molar weight of carbon dioxide, and the internal pressure of the digestion vessel is kept within the range of 0.18-0.19 MPa;

[0030] S3. Raise the temperature in the digestion vessel to 200°C at a rate of 65°C / min, keep it at 190-210°C for 20 minutes, and use a pre-cooled to 7°C under the condition that the pressure in the ...

Embodiment 2

[0032] The present embodiment provides a kind of digestion method of free calcium oxide in steelmaking dedusting ash, and this digestion method comprises the following steps:

[0033] S1. Put the steelmaking dust removal ash in the digestion container; inject carbon dioxide into the digestion container after vacuuming, and repeat the operations of vacuuming and injecting carbon dioxide until the oxygen content in the gas in the digestion container is <1% v / v;

[0034] S2. Inject saturated water vapor into the digestion vessel and adjust the concentration of carbon dioxide so that the molar weight of water molecules in the saturated water vapor is 50% of the molar weight of carbon dioxide, and the internal pressure of the digestion vessel is kept within the range of 0.16-0.18 MPa;

[0035] S3. Raise the temperature in the digestion vessel to 240°C at a rate of 80°C / min, keep it at 230-250°C for 15 minutes, and use a pre-cooled to 5°C under the condition that the pressure in the ...

Embodiment 3

[0037] The present embodiment provides a kind of digestion method of free calcium oxide in steelmaking dedusting ash, and this digestion method comprises the following steps:

[0038] S1. Put the steelmaking dust removal ash in the digestion container; inject carbon dioxide into the digestion container after vacuuming, and repeat the operations of vacuuming and injecting carbon dioxide until the oxygen content in the gas in the digestion container is <1% v / v;

[0039] S2. Inject saturated water vapor into the digestion vessel and adjust the concentration of carbon dioxide so that the molar weight of water molecules in the saturated water vapor is 80% of the molar weight of carbon dioxide, and the internal pressure of the digestion vessel is kept within the range of 0.18-0.20 MPa;

[0040]S3. Raise the temperature in the digestion vessel to 160°C at a rate of 50°C / min, and keep it at 150-170°C for 30 minutes. Carbon dioxide replaces the gas in the digestion vessel, and cools th...

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 relates to the technical field of solid waste treatment, in particular to a method for digesting free calcium oxide in steelmaking dedusting ash. The digestion method mainly comprises the following steps of: putting steelmaking dedusting ash into a digestion container, replacing gas in the digestion container with carbon dioxide, then injecting saturated steam, performing digesting under specific pressure and temperature conditions, replacing gas in the digestion container with precooled carbon dioxide, and performing cooling. According to the digestion method, too high reactiontemperature and pressure are not needed, the needed reaction time is shorter, the digestion efficiency is high, and large-scale digestion of the steelmaking dedusting ash in production is facilitated.The steelmaking dedusting ash obtained after digestion is uniform in particle size distribution, the elemental iron cannot be excessively oxidized in the digestion process, and resource utilization of the steelmaking dedusting ash and recovery of the elemental iron in the steelmaking dedusting ash are facilitated.

Description

technical field [0001] The invention relates to the technical field of solid waste treatment, in particular to a method for dissolving free calcium oxide in steelmaking dust removal dust. Background technique [0002] Steelmaking dust is a by-product of the steelmaking process and can be used as a concrete admixture or aggregate for building materials. However, steelmaking dust removal ash contains more free calcium oxide (f-CaO), which is easy to absorb water and produce volume expansion. When used in building materials, concrete engineering, roads, building material products, etc. can be cracked. Therefore, the free calcium oxide must be digested in the resource utilization of steelmaking dust. [0003] At present, the traditional digestion methods mainly include hot splashing method, water quenching method, wind quenching method, hot stewing method and so on. Compared with other methods, the thermal braising method takes the shortest time, has strong adaptability, and r...

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 Applications(China)
IPC IPC(8): C04B18/08C04B20/02C04B20/04
CPCC04B18/08C04B20/04C04B20/023Y02W30/91
Inventor 任张超于英杰
Owner 河北蓝海智投环保科技有限公司