A kind of calcium carbide slag absorbent and preparation method thereof

A calcium carbide slag and absorbent technology, applied in the field of carbide slag absorbent and its preparation, can solve the problems of high viscosity of wet carbide slag, reduced pore volume of the absorbent, low purity, etc., achieve desulfurization performance improvement, avoid carbonization or Decomposition, the effect of broad application prospects

Active Publication Date: 2022-05-27
FUJIAN LONGKING DSDN ENGINEERING CO LTD +1
View PDF12 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] (1) Low purity: On the one hand, the direct heating of hot flue gas leads to serious carbonization of calcium hydroxide, which reduces the effective desulfurization components; on the other hand, the existing industrial flue gas directly heats carbide slag, and the flue gas temperature usually exceeds 450°C , resulting in the decomposition of calcium hydroxide, resulting in a further decrease in calcium hydroxide in the product
[0007] (2) The specific surface area is small: First, the quicklime blending method contains other components such as silica and calcium carbonate in the quicklime, which will cause some pores to be blocked by fine dust particles during the blending process; secondly, after the quicklime absorbs water and digests The product accounts for a large proportion of the absorbent, and this part of the slaked lime has underdeveloped pores (small porosity), resulting in a small specific surface area of ​​the prepared calcium carbide slag absorbent; finally, the direct hot flue gas drying method, the surface is prone to carbonization, and the newly formed Calcium carbonate is wrapped on the surface of calcium hydroxide, which shields the original pores of carbide slag and further weakens the desulfurization and denitrification activity
[0008] (3) Small pore volume: The size of the pore volume directly affects the absorption capacity of the acid gas. As explained above, the reason for the small specific surface area also leads to a decrease in the pore volume of the absorbent
[0009] (4) Large particle size: Wet calcium carbide slag has high viscosity, no matter chemical drying or direct flue gas drying, it is easy to agglomerate during the drying process, and the particle size is large

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

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0029] The invention provides a kind of preparation method of calcium carbide slag absorbent, comprises the following steps:

[0030] a) Under an air atmosphere at 200°C to 500°C, superfinely pulverize and dry carbide slag with a moisture content of 5wt% to 40wt%, until the moisture content is ≤3wt%, to obtain a carbide slag absorbent;

[0031] The linear velocity of the superfine pulverization and drying medium is 50m / s˜150m / s.

[0032] In the present invention, under the air atmosphere of 200° C. to 500° C., calcium carbide slag with a moisture content of 5 wt % to 40 wt % is ultrafinely pulverized and dried until the moisture content is ≤ 3 wt % to obtain the calcium carbide slag absorbent. In the present invention, the air is preferably clean air. The invention replaces the hot flue gas (generally at 500°C to 700°C) used in the traditional calcium carbide slag drying process with clean air at 200°C to 500°C. On the one hand, it can strictly control the carbon dioxide conc...

Embodiment approach

[0036] (1) Under an air atmosphere at 200°C to 500°C, dry and pulverize calcium carbide slag with a moisture content of 5wt% to 40wt% using a medium with a linear velocity of 50m / s to 150m / s at the same time, using the above-mentioned specific linear velocity The medium is torn or impacted, so that the wet calcium carbide slag is crushed into fine particles by various crushing forces such as shearing, collision, and friction. During the drying process, the particles are ultra-finely divided, and the contact area with the hot air is greatly enhanced. Rapid drying is achieved, so that the prepared calcium carbide slag absorbent does not introduce other dry components, does not introduce new components due to carbonization or decomposition, and avoids the original pore blockage of carbide slag. It has high purity of calcium hydroxide, rich pores, fine particle size, Features such as high desulfurization and denitrification activity.

[0037] (2) Under the air atmosphere of 200℃~5...

Embodiment 1

[0059] (1) 100g of fresh calcium carbide slag with a moisture content of 30wt% is passed into a pulverizer for ultrafine pulverization and drying. , 0.07% CO in hot air 2 ), drying the carbide slag to a moisture content of 1wt%, to obtain dried and crushed carbide slag, which is discharged from the outlet of the pulverizer;

[0060] Record the drying time for all the carbide slag to pass through the outlet of the superfine pulverizer dryer, and test the properties of the samples obtained in Example 1. The characterization data are shown in Table 1.

[0061] (2) Sorting the dried and pulverized calcium carbide slag obtained in step (1), specifically: the materials that meet the drying and pulverization requirements enter the collection area with the updraft to collect high-quality calcium carbide slag absorbent; Under the action of the classifier, the coarse materials that do not meet the crushing requirements are returned to the crushing chamber of the pulverizer for secondar...

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

PropertyMeasurementUnit
specific surface areaaaaaaaaaaa
specific surface areaaaaaaaaaaa
specific surface areaaaaaaaaaaa
Login to view more

Abstract

The invention provides a calcium carbide slag absorbent and a preparation method thereof. The preparation method comprises the following steps: a) under an air atmosphere of 200° C. to 500° C., ultrafine carbide slag with a water content of 5 wt % to 40 wt % Grinding and drying until the moisture content is ≤3wt%, to obtain the calcium carbide slag absorbent; the linear velocity of the superfine grinding and drying medium is 50m / s-150m / s. Compared with the prior art, the preparation method provided by the present invention can maintain the active component of calcium hydroxide in the calcium carbide slag and fully stimulate the desulfurization of the carbide slag during the drying process of the calcium carbide slag through ultrafine pulverization and drying under specific conditions and parameters. activity, to obtain high-quality calcium carbide slag absorbent; the product has the characteristics of high effective calcium hydroxide content, large specific surface area, high pore volume, uniform and small particle size, and the product has significantly improved desulfurization performance indicators. Experimental results show that the high-quality calcium carbide slag absorbent provided by the present invention has an effective calcium hydroxide content ≥ 80wt%, and a specific surface area ≥ 18m 2 / g, pore volume ≥ 0.13cm 3 / g, D50≤20μm, D90≤70μm.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a calcium carbide slag absorbent and a preparation method thereof. Background technique [0002] "Comprehensive pollution control and waste recycling" is one of the key areas of the national medium and long-term scientific and technological development plan, and is closely related to comprehensive resource zoning and excessive resource consumption. As the country pays more and more attention to environmental protection, "ultra-clean emission" will inevitably become the mainstream trend of flue gas treatment of various industrial boilers, and the demand for high-quality absorbents is becoming more and more urgent. Compared with ordinary absorbents, high-quality absorbents have excellent properties such as high purity, high specific surface area, porosity, fine particle size and large pore volume, which can greatly improve desulfurization efficiency, and at the sam...

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): B01D53/81B01D53/50
CPCB01D53/508
Inventor 张志超廖坤添吴慕正赖毅强林珊珊温明英曹岸张原林春源王建春
Owner FUJIAN LONGKING DSDN ENGINEERING CO LTD
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
Try Eureka
PatSnap group products