CN116219159A - Sintered material with flue gas desulfurization ash - Google Patents

Abstract

The invention relates to a sintered material added with flue gas desulfurization ash, which comprises a base material, a flux, flue gas desulfurization ash and an external proportioning material; the base material comprises the following components in percentage by mass: 30% of kali powder, yang Di% of Brazil high silicon powder, 6% of Newman screen powder, 5% of pellets, 2% of miscellaneous ore, 2% of iron oxide scale, 1% of blast furnace primary ash and 2% of steel slag granulated iron; the flux comprises dolomite powder, limestone powder, quicklime powder and sintering powder; the external proportioning material comprises coke powder and return ores. The invention provides a high-efficiency sustainable internal circulation sintering scheme of flue gas desulfurization ash, and the flue gas desulfurization ash serving as a calcium-based material can partially replace fluxing agent used in the sintering process, so that the sintering cost is reduced; at the same time SO generated in the sintering process of the flue gas desulfurization ash ₂ Can be further recycled for sulfuric acid production, thereby creating benefits。

Description

Sintered material with flue gas desulfurization ash

Technical Field

The invention relates to the technical field of desulfurization ash recycling, in particular to a sintered material added with flue gas desulfurization ash.

Background

Sulfur dioxide SO ₂ Is one of the most common pollutants in the atmosphere, SO ₂ The large amount of emission of (3) causes the urban air pollution to be increased continuously, causes great harm to the environment and human health, and is receiving more and more attention worldwide. Considering that the steel industry is the largest SO in China ₂ One of the emission industries, therefore, has conducted extensive researches on flue gas desulfurization methods in steel plants, such as wet, semi-dry, activated carbon adsorption, etc. The wet process technology is mature, the operation is reliable, the desulfurization efficiency is high, but the problem of waste water of the wet process is not relieved, and the byproduct is not free to sell and occupies a large area; the semi-dry method not only reduces the initial investment cost, but also reduces the water consumption, but also has the defects of low desulfurization efficiency, high running cost and the like. In contrast, the dry flue gas desulfurization method injects a calcium-based adsorbent into the flue gas to mix it with SO ₂ The reaction can obtain higher SO without consuming water ₂ The removal rate. However, the by-products of flue gas desulfurization (flue gas desulfurization ash) are usually alkaline and also cause environmental pollution problems. Thus, various recycling techniques are urgently needed to eliminate further pollution.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a sintered material added with flue gas desulfurization ash, which can effectively solve the problems of environmental hazard and the like caused by long-term stacking of the flue gas desulfurization ash.

The technical scheme adopted by the invention is as follows:

the invention provides a sintering material added with flue gas desulfurization ash, which comprises a base material, a flux, the flue gas desulfurization ash and an external proportioning material;

the base material comprises the following components in percentage by mass: 30% of kali powder, yang Di% of Brazil high silicon powder, 6% of Newman screen powder, 5% of pellets, 2% of miscellaneous ore, 2% of iron oxide scale, 1% of blast furnace primary ash and 2% of steel slag granulated iron;

the flux comprises dolomite powder, limestone powder, quicklime powder and sintering powder; the dolomite powder accounts for 3.8% of the total mass of the base material and the flux; the limestone powder accounts for 5.5% of the total mass of the base material and the flux; the quicklime powder accounts for 3.5% of the total mass of the base material and the flux; the sintering powder accounts for 6% of the total mass of the base material and the flux;

the flue gas desulfurization ash accounts for 0.25% of the total mass of the base material and the flux;

the external proportioning material comprises coke powder and return ores; the coke powder accounts for 4% of the total mass of the base material, the flux and the external proportioning material; the return ore accounts for 20% of the total mass of the base material, the flux and the external proportioning material.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a high-efficiency sustainable internal circulation sintering scheme of flue gas desulfurization ash, and the flue gas desulfurization ash serving as a calcium-based material can partially replace fluxing agent used in the sintering process, so that the sintering cost is reduced; at the same time SO generated in the sintering process of the flue gas desulfurization ash ₂ Can be further recycled for sulfuric acid production, thereby creating benefits.

Drawings

FIG. 1 is a schematic diagram of the size distribution of sintered clinker under the condition of adding different proportions of flue gas desulfurization ash;

FIG. 2 is a graph showing the yield of sintered ore and the index of a rotary drum under the condition of adding flue gas desulfurization ash in different proportions;

FIG. 3 shows coke breeze burn-up with different proportions of flue gas desulfurization ash;

FIG. 4 is a graph showing the sintering utilization coefficient under the condition of adding different proportions of flue gas desulfurization ash.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

The invention provides a sintering material added with flue gas desulfurization ash, which comprises a base material, a flux, the flue gas desulfurization ash and an external proportioning material;

the base material comprises the following components in percentage by mass: 30% of kali powder, yang Di% of Brazil high silicon powder, 6% of Newman screen powder, 5% of pellets, 2% of miscellaneous ore, 2% of iron oxide scale, 1% of blast furnace primary ash and 2% of steel slag granulated iron;

the flux comprises dolomite powder, limestone powder, quicklime powder and sintering powder; the dolomite powder accounts for 3.8% of the total mass of the base material and the flux; the limestone powder accounts for 5.5% of the total mass of the base material and the flux; the quicklime powder accounts for 3.5% of the total mass of the base material and the flux; the sintering powder accounts for 6% of the total mass of the base material and the flux;

the flue gas desulfurization ash accounts for 0.25% of the total mass of the base material and the flux;

the external proportioning material comprises coke powder and return ores; the coke powder accounts for 4% of the total mass of the base material, the flux and the external proportioning material; the return ore accounts for 20% of the total mass of the base material, the flux and the external proportioning material.

The flue gas dry desulfurization ash is mixed into sintering raw materials, and the influence rule of the flue gas desulfurization ash with different proportions on the quality index of the sintering ore and the sulfur balance is researched through a sintering cup experiment. Five experimental schemes were designed in total, corresponding to the flue gas desulfurization ash ratios of 0% (benchmark), 0.05%, 0.10%, 0.25% and 0.50%, and the specific bill of materials is summarized in table 1. The sintering cup experiment was carried out by firstly proportioning according to the proportions of table 1, then carrying out water distribution and primary mixing for 15min, then carrying out secondary mixing granulation for 5min, and obtaining the sintering mixed raw material. The sintered mixed raw material was distributed to a sintered cup (diameter 300mm, height 900 mm) by a distributor, and finally was ignited for the experiment. The sintering ignition temperature is 1100 ℃, the ignition time is 120s, the ignition negative pressure is 5.5kPa, the sintering negative pressure is 16.0kPa, and the cooling negative pressure is 8.0kPa.

Table 1 sintered cup experimental plan (raw material ratio:%)

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The test process parameter detection records of the sintering cup are summarized in Table 2 under five different flue gas desulfurization ash ratios.

Table 2 sinter cup experimental process parameter detection

Regarding the product quality index, the grain size distribution of the sintered clinker is shown in figure 1 under five different flue gas desulfurization ash ratios, and compared with the standard, the addition of the desulfurization ash has little influence on the grain size distribution of the sintered clinker; wherein, the proportion of the particles with the particle diameters of more than 40mm is maintained below the level of 2.5%, and the proportion of the particles with the particle diameters of less than 5mm is slightly reduced compared with the standard after the desulfurization ash is added, and particularly, the proportion of the particles with the particle diameters of less than 5mm is less than 20% under the condition of 0.10% desulfurization ash proportion.

Under the condition of adding flue gas desulfurization ash with different proportions, the yield and the drum index of the sinter are shown in figure 2, and as the proportion of the desulfurization ash is increased, the yield and the drum index of the sinter both show the trend of rising and then reducing, and under the condition that the proportion of the desulfurization ash is 0.25%, the yield and the drum index respectively reach 79.14% and 67.7%. Therefore, the Ca in the desulfurization ash plays a key promoting role in the liquid phase formation and the strength improvement of the sinter in the sintering process under the condition of 0.25 percent of desulfurization ash proportion.

Under the condition of adding flue gas desulfurization ash with different proportions, the burning rate of the coke powder in the sintering process is shown in figure 3, and from the figure, the burning rate of the coke powder in the sintering process shows a trend of decreasing first and then increasing second along with the increase of the desulfurization ash proportion, and when the flue gas desulfurization ash proportion is 0.25%, the burning rate of the coke powder is the lowest and is 61.45kg/t, and compared with the standard, the burning rate of the coke powder is reduced by 5.72%.

Further examining the sintering utilization coefficient under the condition of adding flue gas desulfurization ash with different proportions, as shown in fig. 4, the result shows two characteristics: firstly, when the ratio of the desulfurized fly ash is gradually increased from 0.05% to 0.25%, the water distribution is reduced by about 1% compared with the standard, the improvement of the quality index of the sintered mineral products is attributed to the reduction of the vertical sintering speed to a certain extent, and the sintering process time is prolonged from 25min to nearly 32min under the standard condition, so that the bonding of liquid phase in the sintering process is facilitated, and the improvement of the yield and the burnup are facilitated; secondly, when the proportion of the desulfurized fly ash is further increased to the level of 0.50%, the water distribution is restored to the level of 8.3%, under the experimental condition, the air permeability of the material layer is improved along with the improvement of the granulating effect, and the sintering time is shortened to restore the utilization coefficient to 2.16 t.m ^-2 ·h ^-1 Horizontal.

Through analysis of various production quality indexes after the sintering cup experiment, the fact that under the experimental condition, the overall production quality index of the sinter is obviously improved along with the gradual increase of the proportion of the flue gas desulfurization ash to the level of 0.25 percent, which is partially due to the reduction of the vertical sintering speed, can be found, and the full bonding of the liquid phase is promoted. In addition, when the desulfurization ash proportion is increased to the level of 0.50%, the air permeability of the material layer is improved by optimizing granulation through water distribution, and the vertical sintering speed is increased, although the yield and the drum index are reduced, the burnup is increased, but the result is not worse than the result under the condition of not adding desulfurization ash (reference) as a whole.

Therefore, even if the proportion of the flue gas desulfurization ash is at the level of 0.50%, the sintering process index and the quality of the sintered ore are not negatively affected, and the yield and the burnup are improved. At the same time, the acceptable utilization coefficient is 1.8t.m ^-2 ·h ^-1 Under the horizontal condition, the proportion of the flue gas desulfurization ash is more recommended to be controlled at the level of 0.25 percent.

The invention is not a matter of the known technology.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the design of the present invention.

Claims (1)

1. The sintered material added with the flue gas desulfurization ash is characterized by comprising a base material, a flux, the flue gas desulfurization ash and an external proportioning material;

the base material comprises the following components in percentage by mass: 30% of kali powder, yang Di% of Brazil high silicon powder, 6% of Newman screen powder, 5% of pellets, 2% of miscellaneous ore, 2% of iron oxide scale, 1% of blast furnace primary ash and 2% of steel slag granulated iron;

the flux comprises dolomite powder, limestone powder, quicklime powder and sintering powder; the dolomite powder accounts for 3.8% of the total mass of the base material and the flux; the limestone powder accounts for 5.5% of the total mass of the base material and the flux; the quicklime powder accounts for 3.5% of the total mass of the base material and the flux; the sintering powder accounts for 6% of the total mass of the base material and the flux;

the flue gas desulfurization ash accounts for 0.25% of the total mass of the base material and the flux;

the external proportioning material comprises coke powder and return ores; the coke powder accounts for 4% of the total mass of the base material, the flux and the external proportioning material; the return ore accounts for 20% of the total mass of the base material, the flux and the external proportioning material.

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