阅读说明：本技术 一种含有烧结除尘灰小球的烧结矿及制备方法 (Sintered ore containing sintered dedusting ash pellets and preparation method thereof ) 是由 彭道胜 沈文俊 李军 史先菊 蒋国波 李圣辉 于 2020-11-18 设计创作，主要内容包括：一种含有烧结除尘灰小球的烧结矿,其原料组成及wt%含量：混匀矿：65～75%,返矿：15～20%,燃料：3～6%,熔剂：5～10%,粒径≥3mm的烧结除尘灰球：1～15%,粘结剂：0.05～0.98%；制备步骤：将烧结除尘灰辊磨；制备烧结除尘灰球；将混匀矿、返矿、燃料、熔剂粒径不低于3mm的烧结除尘灰球混合均匀；烧结；常规冷却及筛分；制得烧结矿并待用。本发明既能使烧结除尘灰得到综合利用,对环境无污染,成本较低,又能使所制备的烧结矿性能满足使用要求。(A sinter comprising sintered dust removal small ash balls comprises the following raw materials in percentage by weight: mixing ores uniformly: 65-75%, and returning ores: 15-20%, fuel: 3-6% of flux: 5-10%, and sintering dust removal ash balls with the particle size of more than or equal to 3 mm: 1-15%, binder: 0.05-0.98%; the preparation method comprises the following steps: grinding the sintered dedusting ash roller; preparing sintered dedusting ash balls; uniformly mixing the uniformly mixed ore, return ores, fuels and sintered dedusting ash balls with the particle size of the fusing agent not less than 3 mm; sintering; conventional cooling and screening; and preparing sintered ore for later use. The invention not only can comprehensively utilize the sintering dedusting ash, has no pollution to the environment and lower cost, but also can ensure that the performance of the prepared sintering ore meets the use requirement.)

1. The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 65-75%, and returning ores: 15-20%, fuel: 3-6% of flux: 5-10%, sintered dust removal small balls with the particle size of more than or equal to 3 mm: 1-15%, binder: 0.05-0.98%.

2. A sintered ore containing pellets of sintered fly ash according to claim 1, wherein: the binder comprises the following components in percentage by weight: starch: 20-50%, syrup: 20-50% of quicklime and 20-50% of calcium oxide.

3. A sintered ore containing pellets of sintered fly ash according to claim 2, wherein: the syrup is syrup waste liquid.

4. A sintered ore containing pellets of sintered fly ash according to claim 1, wherein: the blending ore is limonite powder ore or hematite powder ore or concentrate powder ore or pellet and lump ore undersize powder or a mixture of two or more of the limonite powder ore or hematite powder ore or pellet and lump ore undersize powder in any proportion.

5. A sintered ore containing pellets of sintered fly ash according to claim 1, wherein: the fuel is coal powder or coke powder or a mixture of the coal powder or the coke powder in any proportion.

6. A sintered ore containing pellets of sintered fly ash according to claim 1, wherein: the flux is dolomite or limestone or quicklime or a mixture of two or more of the dolomite or the limestone and the quicklime in any proportion.

7. A sintered ore containing pellets of sintered fly ash according to claim 1, wherein: the sintering dedusting ash comprises the following chemical components in percentage by weight: TFe: 55-65%, FeO: 13.0-17% of SiO₂:5.5-9.0%、Al₂O₃:2.5-4.5%、MgO：1.5-3.0%。

8. A method of making a sintered ore containing sintered fly ash pellets according to claim 1, comprising the steps of:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash balls: spraying a binder on the sintered dedusting ash obtained in the step 1) to prepare sintered dedusting ash balls with the particle size not less than 3 mm; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 65-75%, and returning ores: 15-20%, fuel: 3-6% of flux: 5-10% of the sintered dedusting ash balls with the grain size not less than 3mm prepared in the step 2), 1-15% of the raw materials are uniformly mixed, and then the materials are distributed in a sintering machine, wherein the thickness of a material layer is controlled to be 550-950 mm;

4) sintering, wherein the sintering ignition time is controlled to be 1-3 min, the ignition negative pressure is 3000-5000 Pa, and the air draft negative pressure is 9000-10000 Pa;

5) carrying out conventional cooling and screening; and preparing sintered ore for later use.

Technical Field

The invention relates to a method for preparing sintered ore, and particularly belongs to a method for preparing sintered ore containing sintered dedusting ash pellets.

Background

In the sintering production process, a large amount of dust is generated in the processes of raw fuel preparation, sintering air draft and crushing and screening of sinter. The dust contains high iron element and beneficial components such as alkali metal. According to statistics, the dust generated by the sintering process accounts for 2% -4% of the output of the sintering ore, and the total amount of the dust removed by the sintering dust removal system is more than 1500 ten thousand tons every year. If the dedusting ash can be efficiently and intensively treated, not only can energy be saved and emission can be reduced, but also the cyclic utilization of solid waste resources can be realized.

At present, the application of the iron-containing dust is mainly to use the iron-containing dust for sintering, so that the iron-containing dust is intensively and efficiently treated in a steel plant. Because the sintering dedusting ash has the characteristics of fine granularity, strong hydrophobicity and poor granulating effect, the direct addition of the sintering dedusting ash into the mixture can deteriorate the granulating effect of the mixture, thus leading to poor air permeability of a sinter bed and further reducing the production quality of sinter.

In recent years, a process for the composite agglomeration of iron ore powder is developed domestically, aiming at some iron-containing materials difficult to agglomerate, the iron-containing materials are firstly prepared into pellets separately in advance, and then are mixed with the iron ore powder, a flux, a fuel and the like for sintering, so that the high-efficiency treatment of the iron-containing materials difficult to agglomerate can be realized, such as the following steps:

the Chinese patent application No. 201510550944.0 discloses a preparation method of a pellet material of carbon-containing and iron-containing dust difficult to pelletize and application of the pellet material in an iron ore powder composite agglomeration process, which comprises the steps of firstly grinding the carbon-containing and iron-containing dust by a high-pressure roller, then adding humic acid modified bentonite as a binder for pelletizing, and then mixing the dust pellets with other raw materials and then paving the mixture on a sintering machine for roasting.

The invention discloses a Chinese invention patent application No. 201510594704.0, which is an efficient sintering method for iron-containing dust, wherein quicklime or hydroxypropyl cellulose or a mixture of the quicklime and the hydroxypropyl cellulose is used as a binder, low-zinc iron-containing dust collected in an iron making area is made into small balls with the size of 3-12 mm on a disc pelletizer, and then the dust balls are mixed into a mixture for sintering.

The Chinese patent application No. 201810974532.3 discloses a method for treating iron-containing dust by using a sintering process, which comprises the steps of spraying hydrated lime suspension on fly ash, granulating into fly ash particles with the particle size of more than 3mm, uniformly mixing the fly ash particles with other sintering raw materials in a cylindrical mixer, and sintering the obtained mixture.

The Chinese patent application No. 201510550944.0 solves the problems of difficult pelletizing and low green pellet strength of carbon-containing and iron-containing dust, but the added humic acid modified bentonite is difficult to prepare, and elements such as silicon and the like can be brought in to reduce the grade of sinter.

The patent with the patent application number of 201510594704.0 in China uses the dust removal ash to prepare pellets with better strength for sintering, but the pelletizing process is complex, the production capacity is lower, and the requirement of a sintering machine on the consumption of raw materials cannot be met. The patent with the patent application number of 201810974532.3 in the invention of China utilizes a cylinder mixer to spray slaked lime liquid on dust removal particles for pre-granulation and then is mixed with a mixture for sintering, so that the quality of sintered mineral products can be improved, but the production cost is overhigh due to the high proportion of slaked lime.

Disclosure of Invention

The invention aims to provide a sintered ore containing sintered dedusting ash pellets and a preparation method thereof, aiming at the defects that the sintered dedusting ash has strong hydrophobicity and poor balling property, the quality of sintered ore products is reduced due to direct burdening and sintering, and the like, the sintered dedusting ash can be comprehensively utilized, the environment is not polluted, the cost is lower, and the performance of the prepared sintered ore can meet the use requirement.

The measures for realizing the aim are as follows:

the sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 65-75%, and returning ores: 15-20%, fuel: 3-6% of flux: 5-10%, and sintering dust removal ash balls with the particle size of more than or equal to 3 mm: 1-15%, binder: 0.05-0.98%.

It is characterized in that: the binder comprises the following components in percentage by weight: starch: 20-50%, syrup: 20-50% of quicklime and 20-50% of calcium oxide.

It is characterized in that: the syrup is syrup waste liquid.

It is characterized in that: the blending ore is limonite powder ore or hematite powder ore or concentrate powder ore or pellet and lump ore undersize powder or a mixture of two or more of the limonite powder ore or hematite powder ore or pellet and lump ore undersize powder in any proportion.

It is characterized in that: the fuel is coal powder or coke powder or a mixture of the coal powder or the coke powder in any proportion.

It is characterized in that: the flux is dolomite or limestone or quicklime or a mixture of two or more of the dolomite or the limestone and the quicklime in any proportion.

It is characterized in that: the sintering dedusting ash comprises the following chemical components in percentage by weight: TFe: 55-65%, FeO: 13.0-17% of SiO₂:5.5-9.0％、Al₂O₃:2.5-4.5％、MgO：1.5-3.0％。

A method for preparing a sinter comprising sintered fly ash pellets, comprising the steps of:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash balls: spraying a binder on the sintered dedusting ash obtained in the step 1) to prepare sintered dedusting ash balls with the particle size not less than 3 mm; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 65-75%, and returning ores: 15-20%, fuel: 3-6% of flux: 5-10% of the sintered dedusting ash balls with the grain size not less than 3mm prepared in the step 2), 1-15% of the raw materials are uniformly mixed, and then the materials are distributed in a sintering machine, wherein the thickness of a material layer is controlled to be 550-950 mm;

4) sintering, wherein the sintering ignition time is controlled to be 1-3 min, the ignition negative pressure is 3000-5000 Pa, and the air draft negative pressure is 9000-10000 Pa;

5) carrying out conventional cooling and screening; and preparing sintered ore for later use.

Compared with the prior art, the invention has the characteristics that:

1) the invention adds the binder into the sintering dedusting ash which is difficult to pelletize, then the sintering dedusting ash is agglomerated into dedusting ash pellets through the treatment of the prefabricated pellets, and then the dedusting ash pellets are mixed with other sintering raw materials and sintered, the sintering dedusting ash is applied to sintering by using the method of the invention, the average grain diameter of the sintering mixture is improved by 10-20%, and the sintering yield is improved by 5-10%.

2) Compared with the existing process for sintering the dust removal ash after granulation, the invention reduces the addition amount of the binder by 10-20% under the condition of ensuring the strength of the dust removal ash small balls, and reduces the processing cost; in addition, compared with traditional binders such as bentonite and the like, the binder used in the invention can not bring silicon element, and can not reduce the iron grade of the fly ash.

3) The method treats the prefabricated particles of the sintering dedusting ash, aggregates the fine dedusting ash which is easy to float into small balls and adds the small balls into the sintering bedding material, and avoids the pollution of the sintering dedusting ash to the production environment. The sintering dedusting ash can be comprehensively utilized, the added flux has no pollution to the environment, the cost is lower, and the performance of the prepared sintered pellets can meet the use requirement.

Detailed Description

The present invention is described in detail below:

comparative example

The dedusting ash is directly added into a blending material in a ratio of 5% without treatment for blending, and the blending material comprises the following raw materials in percentage by weight: mixing ores uniformly: 69%, return fines: 18%, fuel: 3% of a flux: 5 percent;

the uniformly mixed ore consists of 50% of limonite, 40% of hematite and 10% of concentrate powder by mass fraction, the flux is a mixture of dolomite, limestone and quicklime according to the proportion of 1:1:2, and the fuel is coke powder;

and (3) distributing the uniformly mixed and granulated mixture on a sintering trolley for ignition and sintering, wherein the height of the material layer is 700mm, the ignition time is 1.5 minutes, the ignition negative pressure is 4500Pa, and the air draft negative pressure in the sintering process is 9000 Pa.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 4.1mm, and the air permeability resistance of the sintering material layer is 94.0mmH₂O, the vertical sintering speed is 21.10mm/min, the sintering solid fuel consumption is 70.33Kg/t, the sinter yield is 70.97%, and the drum strength is 60.13%.

Example 1

The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 69%, return fines: 18%, fuel: 3% of a flux: 4.92 percent, sintered dust removal ash balls with the grain diameter not less than 3 mm: 5 percent and 0.08 percent of binder;

the uniformly mixed ore consists of 50 mass percent of limonite, 40 mass percent of hematite and 10 mass percent of concentrate powder;

the flux is a mixture of dolomite, limestone and quicklime in a ratio of 1:1: 2;

the fuel is coke powder;

the raw material composition of the adhesive is as follows: 36% of starch, 22% of syrup and 42% of quicklime;

the preparation process comprises the following steps:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash pellets: spraying 0.08% of binder on the sintered dedusting ash obtained in the step 1), and preparing sintered dedusting ash balls with the particle size being more than or equal to 3mm by using a cylindrical mixer; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 69%, return fines: 18%, fuel: 3% of a flux: 4.92 percent, sintered dust removal ash balls with the grain diameter not less than 3 mm: 5 percent of raw materials are uniformly mixed and then are laid in a sintering machine, and the laying thickness is controlled to be 700 mm;

4) sintering, controlling the ignition time of sintering to be 1.5min, controlling the ignition negative pressure to be 4500Pa, and controlling the air draft negative pressure to be 9000 Pa;

5) carrying out conventional cooling and screening; and preparing the sinter pellets for later use.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 4.8mm, and the air permeability resistance of the sintering material layer is 93.5mmH₂O, the vertical sintering speed is 21.24mm/min, the sintering solid fuel consumption is 70.23Kg/t, the sinter yield is 71.97%, and the drum strength is 60.85%.

Example 2

The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 65%, return fines: 16%, fuel: 6% and flux: 5.9 percent, sintered dust removal ash balls with the grain diameter not less than 3 mm: 7 percent of binder, 0.10 percent of adhesive;

mixing the limonite with the mixed ore to obtain 100 percent limonite;

the flux is a mixture of dolomite, limestone and quicklime in a ratio of 1:1: 2;

the fuel is a mixture of pulverized coal and coke powder in any proportion;

the raw material composition of the adhesive is as follows: 23% of starch, 46% of syrup and 31% of quicklime;

the preparation process comprises the following steps:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash pellets: spraying a binder with the weight percentage of 0.10% of the sintering dedusting ash on the sintering dedusting ash in the step 1), and preparing sintering dedusting ash balls with the particle size of more than or equal to 3mm by using a cylindrical mixer; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 65%, return fines: 16%, fuel: 6% and flux: 5.9 percent, sintered dust removal ash balls with the grain diameter not less than 3 mm: 7 percent of raw materials are uniformly mixed and then are laid in a sintering machine, and the laying thickness is controlled to be 585 mm;

4) sintering, controlling the ignition time of sintering to be 1.9min, and controlling the ignition negative pressure to be 3500Pa and the ventilation negative pressure to be 9080 Pa;

5) carrying out conventional cooling and screening; and preparing the sinter pellets for later use.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 5.0mm, and the air permeability resistance of the sintering material layer is 92.7 mmH₂O, the vertical sintering speed is 21.60mm/min, the sintering solid fuel consumption is 69.9Kg/t, the sinter yield is 72.52%, and the drum strength is 61.25%.

Example 3

The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 71%, return fines: 15%, fuel: 4.55%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: 2 percent; 0.45% of a binder;

mixing the ore evenly to obtain 100% lump ore undersize;

the flux is a mixture of dolomite, limestone and quicklime in a ratio of 1:1: 2;

the fuel is pulverized coal;

the raw material composition of the adhesive is as follows: 41% of starch, 35% of syrup and 24% of quicklime;

the preparation process comprises the following steps:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash pellets: spraying an adhesive with the weight percentage of 0.45% of the sintering dust removal ash on the sintering dust removal ash in the step 1), and preparing sintering dust removal ash balls with the particle size of more than or equal to 3mm by using a cylindrical mixer; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 71%, return fines: 15%, fuel: 4.55%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: 2 percent of raw materials are uniformly mixed and then are laid in a sintering machine, and the laying thickness is controlled to be 630 mm;

4) sintering, controlling the ignition time of sintering to be 2.9min, controlling the ignition negative pressure to be 4100Pa and controlling the air draft negative pressure to be 9350 Pa;

5) carrying out conventional cooling and screening; and preparing the sinter pellets for later use.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 5.2mm, and the air permeability resistance of the sintering material layer is 91.2 mmH₂O, the vertical sintering speed is 21.66mm/min, the sintering solid fuel consumption is 69.3Kg/t, the sinter yield is 72.95 percent, and the drum strength is 61.3 percent.

Example 4

The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 66%, return ores: 17%, fuel: 3.3%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: 6 percent; 0.7% of a binder;

mixing the ore uniformly to obtain 100% pellets;

the flux is a mixture of dolomite, limestone and quicklime in a ratio of 1:1: 2;

the fuel is pulverized coal;

the raw material composition of the adhesive is as follows: 47% of starch, 25% of syrup and 28% of quicklime;

the preparation process comprises the following steps:

1) the dedusting ash generated by sintering is subjected to high-pressure roller milling, so that the specific surface area of the dedusting ash after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash pellets: spraying an adhesive with the weight percentage of 0.7% of the sintering dust removal ash on the sintering dust removal ash in the step 1), and preparing sintering dust removal ash balls with the particle size of more than or equal to 3mm by using a cylindrical mixer; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 66%, return ores: 17%, fuel: 3.3%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: uniformly mixing 6% of the raw materials, and then paving in a sintering machine, wherein the paving thickness is controlled to be 820 mm;

4) sintering, controlling the sintering ignition time to be 2.5min, controlling the ignition negative pressure to be 5000Pa and controlling the air draft negative pressure to be 9980 Pa;

5) carrying out conventional cooling and screening; and preparing the sinter pellets for later use.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 4.8mm, and the air permeability resistance of the sintering material layer is 93.7mmH₂O, the vertical sintering speed is 21.29mm/min, the sintering solid fuel consumption is 70.13Kg/t, the sinter yield is 71.99 percent, and the drum strength is 60.93 percent.

Example 5

The sintered ore containing sintered dedusting ash pellets comprises the following raw materials in percentage by weight: mixing ores uniformly: 68%, return ores: 15%, fuel: 5.02%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: 4 percent; 0.98% of a binder;

the mixed ore is pure hematite;

the flux is a mixture of dolomite, limestone and quicklime in a ratio of 1:1: 2;

the fuel is coke powder;

the raw material composition of the adhesive is as follows: 21% of starch, 31% of syrup and 48% of quicklime; (ii) a

The preparation process comprises the following steps:

1) removing by sinteringDust is subjected to high-pressure roller milling, so that the specific surface area of the dust removed after roller milling reaches 1500cm²·g^-1The above;

2) preparing sintered dedusting ash pellets: spraying an adhesive with the weight percentage of 0.98% of the sintering dust removal ash on the sintering dust removal ash in the step 1), and preparing sintering dust removal ash balls with the particle size of more than or equal to 3mm by using a cylindrical mixer; returning to continue granulating if the particle size is less than 3 mm;

3) mixing the ore: 68%, return ores: 15%, fuel: 5.02%, flux: 7 percent, sintered dust removal ash balls with the particle size of more than or equal to 3 mm: uniformly mixing 4% of the raw materials, and then paving in a sintering machine, wherein the paving thickness is controlled to be 890 mm;

4) sintering, controlling the sintering ignition time to be 2min, the ignition negative pressure to be 4200Pa, and the air draft negative pressure to be 9750 Pa;

5) carrying out conventional cooling and screening; and preparing the sinter pellets for later use.

Through detection and trial, the average grain diameter of the obtained sintering mixture is 4.75mm, and the air permeability resistance of the sintering material layer is 93.9mmH₂O, the vertical sintering speed is 21.30mm/min, the sintering solid fuel consumption is 70.26Kg/t, the sinter yield is 71.90%, and the drum strength is 60.78%.

The above examples are merely preferred examples and are not intended to limit the embodiments of the present invention.