CN115874047A - Fluxed pellet containing specularite and preparation method thereof - Google Patents
Fluxed pellet containing specularite and preparation method thereof Download PDFInfo
- Publication number
- CN115874047A CN115874047A CN202211541274.2A CN202211541274A CN115874047A CN 115874047 A CN115874047 A CN 115874047A CN 202211541274 A CN202211541274 A CN 202211541274A CN 115874047 A CN115874047 A CN 115874047A
- Authority
- CN
- China
- Prior art keywords
- specularite
- percent
- magnetite
- pellets
- pellet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention aims to solve the problems of effective use of specularite in pellet production in the prior art, and provides a fluxed pellet containing specularite and a preparation method thereof. The technical scheme of the fluxed pellet containing specularite comprises the following raw materials in percentage by mass: 80 to 100 percent of specularite (calculated by dry ore), 20 to 0 percent of magnetite (calculated by dry ore), 7 to 12 percent of anthracite powder, 1.0 to 5.5 percent of limestone powder and 1.5 to 2.5 percent of composite bentonite; and the alkalinity ranges from 0.6 to 1.2. The addition proportion of specularite is larger, the addition of other raw materials can not reduce the iron grade of the pellet, and the cost of the pellet is reduced.
Description
Technical Field
The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a technology for producing oxidized pellets by specularite.
Background
In recent years, pellets have become important charging materials for blast furnace iron making, and the importance of the molten pellets is increasing for iron and steel enterprises. The high-quality magnetite concentrate obtained by mineral separation is mainly used for producing the pellet, and the production cost of the high-quality iron concentrate is higher. In order to reduce the production cost and improve the performance index of the pellet as much as possible, iron and steel enterprises begin to explore specularite which is considered not to be suitable for pellet production before the specularite is added into iron ore concentrate. Specularite, as an iron ore, has the advantages of high iron grade, less harmful impurities, large existing reserves and relatively low price. However, as the specularite has good crystal size, smooth particle surface and compact structure, the hydrophilicity and the balling performance of the specularite are poor, and the balling is not easy to occur or the balling index is poor when the specularite is used. Meanwhile, due to poor high-temperature reaction performance of specularite, low-melting-point compounds are difficult to form, and recrystallization interconnection among particles is difficult to form, so that the specularite pellets have poor preheating pellet indexes and low pellet strength. Due to the defects, specularite still cannot be applied to the pellet industry in a large proportion at present.
In order to effectively utilize specularite resources, the prior art researches on the production of pellets by using specularite.
As mentioned in Zhang Daoyuan of the university of China, specularite is pretreated when the specific surface area of the specularite reaches 1600cm 2 After the production of the pellets, 1.0 percent of special binder MHA is adopted for pelletizing, and the green pellet index can basically meet the production requirement. The Zhu Deqing of the university of south and middle schools teaches that the reinforcing measures for specularite in pellet production are to use high-quality and high-efficiency binders, produce melt pellets, add fuel in batches, mechanically activate and the like, and various reinforcing measures can be comprehensively used in field production to achieve the purpose of improving the pelletizing effect. However, the above researchers all mention that the amount of specularite added in the pellet should not exceed 20%. In order to improve the use proportion of specularite, the Tang Yanyun university of Central and south also researches the strengthening of Brazilian specularite pellets by adopting a high-pressure roller milling process, and the result shows that the blending amount of the specularite can reach 70% through mechanical activation when the specularite and magnetite are mixed for use. The study also indicates that the preheating temperature of the pellets after mechanical activation is still above 1000 ℃. The technical problem of preparing pellets by using single Brazilian specularite is solved by adding the iron-containing miscellaneous materials and limestone mud cakes in the Brazilian specularite and carrying out wet grinding on the mixture, and the research has clear requirements on the properties of the raw materials, and the preheating time and the roasting time are both 15min.
Some patents also describe processes for making pellets from specularite, e.g.The patent application No. CN202010645043.0 discloses a method for producing oxidized pellet ore by adopting specularite, and the specific surface area is more than or equal to 1200cm 2 Specularite/g, specific surface area not less than 1400cm 2 The magnetite per g, the sintered return mine with the content of-200 meshes being more than or equal to 85 percent and the composite bentonite are mixed and pelletized, and the materials are mixed according to the weight proportion of dry materials and are mixed for pelletizing. The pellets are preheated at 950-980 ℃ for 10min, and roasted at 1200-1250 ℃ for 10min to obtain roasted pellets with the compressive strength of more than or equal to 2300N per pellet. In pellet production, sintered return ores are added, the return ores are products of a sintering plant and generally return to sintering production, although the addition of the return ores with certain alkalinity can improve the generation of liquid phase in the pellets and further improve the strength of the pellets, the process is relatively complex, and the sintered return ores can reduce the grade of the pellets and have higher cost. For example, patent No. CN201610056164.5 discloses a roasting method of high-proportion specularite, wherein the specific surface area of the specularite after being subjected to high-pressure roller milling is up to 2000cm 2 The blending amount of specularite can reach 60 to 75 percent when the pellet is used for producing pellets, but the preheating temperature of the pellets is still higher and is 1100 to 1180 ℃.
Significant research efforts have been required for the effective use of specularite in pellet production, particularly for fluxed pellets.
Disclosure of Invention
The invention aims to solve the problems of effective use of specularite in pellet production in the prior art, and provides a fluxed pellet containing specularite and a preparation method thereof. The addition proportion of specularite is larger, the addition of other raw materials can not reduce the iron grade of the pellet, and the cost of the pellet is reduced.
The purpose of the invention is realized by the following technical scheme:
the invention relates to a fluxed pellet containing specularite, which comprises the following raw materials in percentage by mass: 80 to 100 percent of specularite (calculated by dry ore), 20 to 0 percent of magnetite (calculated by dry ore), 7 to 12 percent of anthracite powder, 1.0 to 5.5 percent of limestone powder and 1.5 to 2.5 percent of composite bentonite; and the alkalinity ranges from 0.6 to 1.2.
Furthermore, the specific surface area of the fluxed pellet containing specularite is more than or equal to 1200cm 2 (ii)/g; the content of the anthracite powder with the granularity of-200 meshes is more than or equal to 95 percent; the magnetite is magnetite concentrate with specific surface area not less than 1500cm 2 /g。
Further, the fluxed pellet containing specularite comprises the following components in percentage by mass: 30-50% of corn starch, 20-30% of bamboo fiber and 20-40% of sodium bentonite.
The invention relates to a preparation method of fluxed pellets containing specularite, which comprises the following steps:
step one, raw material preparation
Crushing specularite by high-pressure roller mill to make the specific surface area of specularite greater than or equal to 1200cm 2 (ii)/g; fine grinding the anthracite powder by a ball mill until the content of-200 meshes is more than or equal to 95 percent; taking magnetite concentrate, extruding and crushing the magnetite concentrate by using a high-pressure roller mill, wherein the specific surface area of the magnetite concentrate is more than or equal to 1500cm 2 /g；
Step two, batching and balling
Proportionally mixing the specularite, the magnetite and the anthracite powder obtained in the step one with the limestone powder and the composite bentonite, and controlling the alkalinity range of the mixed raw materials to be 0.6-1.2; uniformly mixing the mixed raw materials, pelletizing, controlling the total water content of the mixed raw materials to be 7.5-8.5% of the dry weight of specularite and magnetite, mixing the raw materials to obtain green pellets, and drying for later use;
step three, preheating and roasting
Preheating and roasting the dried green balls obtained in the step two, and obtaining preheated balls under the conditions that the preheating temperature is 950-1000 ℃ and the preheating time is 9-11 min; then the preheated ball is roasted for 9-11 min at the temperature of 1200-1250 ℃ to obtain the roasted ball.
Further, in the above method for producing fluxed pellets containing specularite, in the second step, the green pellets have the following strength parameters: the falling strength is more than or equal to 5.0 times per ball, and the compressive strength is more than or equal to 10.0N per ball.
Further, in the preparation method of the fluxed pellets containing specularite, in the third step, the compressive strength of the obtained preheated pellets is more than or equal to 450N per pellet; the compressive strength of the obtained roasted balls is more than or equal to 2300N/ball.
Compared with the prior art, the invention has the advantages that:
1. the specific surface area of the specularite used in the invention is relatively low;
2. the blending proportion of specularite is larger and is in the range of 80-100%;
3. when the compressive strength of the preheating balls is more than or equal to 450N/ball, the preheating temperature is 950-1000 ℃, the preheating time is 9-11 min, the preheating temperature is relatively low, the preheating time is relatively short, and the energy is saved and the consumption is reduced;
4. when the compressive strength of the roasted balls is more than or equal to 2500N/ball, the roasting temperature is 1200-1250 ℃, the roasting time is 9-11 min, the roasting temperature is relatively low, the roasting time is relatively short, and the energy is saved and the consumption is reduced;
5. the magnetite, the anthracite powder, the limestone powder and the composite bentonite matched with the specularite are all easily obtained;
6. the composite bentonite adopted in the invention can reduce the usage amount of the bentonite, and can also ensure that the pellets obtained by mixing specularite, magnetite, anthracite powder and limestone powder can obtain good performance before entering the preheating section, but the effect can not be realized by singly mixing the corn starch and the bentonite or mixing the bamboo fiber and the bentonite.
Detailed Description
Example 1
A method for preparing fluxed pellets containing specularite, comprising the steps of:
step one, raw material preparation
Example 1 the main chemical components of specularite and magnetite are shown in table 1:
TABLE 1
The specific surface area of the specularite is increased to 1200cm after the specularite is subjected to high-pressure roller milling 2 More than g, the specific surface area of the magnetite is 1570cm 2 The-200 mesh content of the limestone powder, the anthracite powder and the composite bentonite accounts for more than 95 percent;
step two, batching and balling
Under the condition that the alkalinity of the pellet ore is 0.6, the mass percentage ratio of the concentrate is as follows: specularite (calculated as dry ore) 80%, magnetite (calculated as dry ore) 20.0%. The external additive contains 7 percent of anthracite powder, 1.8 percent of composite bentonite and 4.2 percent of limestone powder. The composite bentonite comprises 30% of corn starch, 30% of bamboo fiber and 40% of sodium bentonite in percentage by mass. Controlling the total water content of the mixed raw materials to be 7.5% of the dry weight of specularite and magnetite, uniformly mixing the materials, and then balling on a disc pelletizer to obtain green pellets with the falling strength of 5.8 times per pellet and the compressive strength of 12.0N per pellet;
step three, preheating and roasting
After drying the green pellets, preheating and roasting the green pellets on a horizontal tube furnace, and obtaining preheated pellets under the conditions that the preheating temperature is 950 ℃ and the preheating time is 10min, wherein the compressive strength of the preheated pellets is about 560N per pellet; then the balls are preheated to obtain the roasted balls under the conditions that the roasting temperature is 1200 ℃ and the roasting time is 10min, and the compression strength of the roasted balls is 2840N/ball.
Example 2
Step one, raw material preparation
Example 2 the starting materials used were the same as in example 1.
Step two, batching and balling
Under the condition that the alkalinity of the pellet ore is 0.8, the mass percentage ratio of the concentrate is as follows: specularite (calculated as dry ore) 90%, magnetite (calculated as dry ore) 10%. 9 percent of anthracite powder, 2.0 percent of composite bentonite and 3.8 percent of limestone powder are added externally. The composite bentonite comprises 40% of corn starch, 20% of bamboo fiber and 40% of sodium bentonite in percentage by mass. Controlling the total water content of the mixed raw materials to be 8% of the dry weight of specularite and magnetite, uniformly mixing the materials, and then balling on a disc pelletizer to obtain green pellets with the falling strength of 5.2 times per pellet and the compressive strength of 11.8N per pellet;
step three, preheating and roasting
After drying, preheating and roasting the green pellets on a horizontal tube furnace, and obtaining preheated pellets under the conditions that the preheating temperature is 960 ℃ and the preheating time is 10min, wherein the compressive strength of the preheated pellets is about 530N/pellet; then the balls are preheated to obtain roasted balls under the conditions that the roasting temperature is 1200 ℃ and the roasting time is 10min, and the compressive strength of the roasted balls is 2600N/ball.
Example 3
Step one, raw material preparation
Example 3 the same starting materials as used in example 1 were used.
Step two, batching and balling
Under the condition that the alkalinity of the pellet ore is 1.0, the mass percentage ratio of the concentrate is as follows: specularite (calculated as dry ore) 90%, magnetite (calculated as dry ore) 10%. 9 percent of anthracite powder, 2.1 percent of composite bentonite and 4.6 percent of limestone powder are added externally. The composite bentonite comprises 50% of corn starch, 30% of bamboo fiber and 20% of sodium bentonite in percentage by mass. Controlling the total water content of the mixed raw materials to be 7.5% of the dry weight of specularite and magnetite, uniformly mixing the materials, and then balling on a disc pelletizer to obtain green pellets with the falling strength of 5.5 times per pellet and the compressive strength of 12.1N per pellet;
step three, preheating and roasting
After drying, preheating and roasting the green pellets on a horizontal tube furnace, and obtaining preheated pellets under the conditions that the preheating temperature is 970 ℃ and the preheating time is 10min, wherein the compressive strength of the preheated pellets is about 503N/pellet; then the preheated balls are roasted at the roasting temperature of 1200 ℃ for 10min to obtain roasted balls, and the compressive strength of the roasted balls is about 2480N/ball.
Example 4
Step one, raw material preparation
Example 4 the starting materials used were the same as in example 1.
Step two, batching and balling
Under the condition that the alkalinity of the pellet ore is 1.2, the mass percentage ratio of the concentrate is as follows: specularite (dry basis) 100%, magnetite 0. The external additive contains 10% of anthracite powder, 2.5% of composite bentonite and 5.5% of limestone powder. The composite bentonite comprises 45% of corn starch, 25% of bamboo fiber and 30% of sodium bentonite in percentage by mass. Controlling the total water content of the mixed raw materials to be 8.5% of the dry weight of specularite, uniformly mixing the materials, and then balling on a disc pelletizer to obtain green pellets with the falling strength of 5.9 times per pellet and the compressive strength of 12.0N per pellet;
step three, preheating and roasting
After drying the green pellets, preheating and roasting the green pellets on a horizontal tube furnace, and obtaining preheated pellets under the conditions that the preheating temperature is 1000 ℃ and the preheating time is 10min, wherein the compressive strength of the preheated pellets is about 510N/pellet; then the pre-heating balls are roasted at the roasting temperature of 1250 ℃ for 10min to obtain roasted balls, and the compression strength of the roasted balls is about 2430N per ball.
Example 5
Step one, raw material preparation
Example 5 the same starting materials as used in example 1 were used.
Step two, batching and balling
Under the condition that the alkalinity of the pellet ore is 1.2, the mass percentage ratio of the concentrate is as follows: specularite (dry basis) 100%, magnetite 0. 9 percent of anthracite powder, 2.3 percent of composite bentonite and 5.1 percent of limestone powder are added externally. The composite bentonite comprises 45% of corn starch, 25% of bamboo fiber and 30% of sodium bentonite in percentage by mass. Controlling the total water content of the mixed raw materials to be 8% of the dry weight of specularite, uniformly mixing the materials, and then balling on a disc pelletizer to obtain green pellets with the falling strength of 5.0 times per pellet and the compressive strength of 10.0N per pellet;
step three, preheating and roasting
After drying the green pellets, preheating and roasting the green pellets on a horizontal tube furnace, and obtaining preheated pellets under the conditions that the preheating temperature is 1000 ℃ and the preheating time is 10min, wherein the compressive strength of the preheated pellets is about 480N per pellet; then the pre-heating ball is roasted at the roasting temperature of 1250 ℃ for 10min to obtain the roasted ball, and the compression strength of the roasted ball is about 2320N per ball.
Claims (6)
1. The fluxed pellet containing specularite is characterized by comprising the following raw materials in percentage by mass: 80 to 100 percent of specularite calculated by dry ore, 20 to 0 percent of magnetite calculated by dry ore, 7 to 12 percent of anthracite powder, 1.0 to 5.5 percent of limestone powder and 1.5 to 2.5 percent of composite bentonite; and the alkalinity ranges from 0.6 to 1.2.
2. The fluxed pellet containing specularite as claimed in claim 1, wherein the specific surface area of specularite is not less than 1200cm 2 /g；
The content of the anthracite powder with the granularity of-200 meshes is more than or equal to 95 percent;
the magnetite raw material is magnetite concentrate with specific surface area not less than 1500cm 2 /g。
3. The fluxed pellet containing specularite as claimed in claim 1, wherein the composite bentonite comprises the following components in percentage by mass: 30-50% of corn starch, 20-30% of bamboo fiber and 20-40% of sodium bentonite.
4. The method of making fluxed pellets containing specularite as claimed in any of claims 1 to 3, characterized by comprising the steps of:
step one, raw material preparation
Crushing specularite by high-pressure roller mill to make the specific surface area of specularite greater than or equal to 1200cm 2 (ii)/g; fine grinding the anthracite powder by a ball mill until the content of-200 meshes is more than or equal to 95 percent; taking magnetite concentrate, extruding and crushing the magnetite concentrate by a high-pressure roller mill, wherein the specific surface area of the magnetite concentrate is more than or equal to 1500cm 2 /g；
Step two, batching and balling
Proportioning specularite, magnetite and anthracite powder obtained in the step one, limestone powder and composite bentonite according to a proportion, and controlling the alkalinity range of the mixed raw materials to be 0.6-1.2; uniformly mixing the mixed raw materials, pelletizing, controlling the total water content of the mixed raw materials to be 7.5-8.5% of the dry weight of specularite and magnetite to obtain green pellets, and drying for later use;
step three, preheating and roasting
Preheating and roasting the dried green balls obtained in the step two, and obtaining preheated balls under the conditions that the preheating temperature is 950-1000 ℃ and the preheating time is 9-11 min; then the preheated balls are roasted for 9-11 min at the temperature of 1200-1250 ℃ to obtain the roasted balls.
5. The method of making fluxed pellets containing specularite as claimed in claim 4, wherein in step two, the green pellets have the following strength parameters: the falling strength is more than or equal to 5.0 times per ball, and the compressive strength is more than or equal to 10.0N per ball.
6. The method for preparing fluxed pellets containing specularite as claimed in claim 4, wherein in step three, the compressive strength of the obtained preheated pellets is not less than 450N/pellet; the compressive strength of the obtained roasted balls is more than or equal to 2300N/ball.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211541274.2A CN115874047A (en) | 2022-12-02 | 2022-12-02 | Fluxed pellet containing specularite and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211541274.2A CN115874047A (en) | 2022-12-02 | 2022-12-02 | Fluxed pellet containing specularite and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115874047A true CN115874047A (en) | 2023-03-31 |
Family
ID=85765645
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211541274.2A Pending CN115874047A (en) | 2022-12-02 | 2022-12-02 | Fluxed pellet containing specularite and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115874047A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116287680A (en) * | 2023-04-23 | 2023-06-23 | 中天钢铁集团(南通)有限公司 | Specularite pellet production method |
-
2022
- 2022-12-02 CN CN202211541274.2A patent/CN115874047A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116287680A (en) * | 2023-04-23 | 2023-06-23 | 中天钢铁集团(南通)有限公司 | Specularite pellet production method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101649392B (en) | Pelletizing method of ilmenite concentrates and pellet binder | |
| CN102206744B (en) | Method for granulating sinter mixture | |
| CN111254278B (en) | Oxidized pellet binder prepared from low-rank coal and preparation method and application thereof | |
| CN109266847B (en) | Preparation method of low-temperature consolidated metallurgical pellets | |
| CN103602804B (en) | A kind of high performance pellet binder | |
| CN103627895B (en) | Production method for sintering chromium powder ore by continuous strand sinter machine | |
| CN103451421B (en) | A kind of preparation method of blast furnace gas mud pre-reduced pellet | |
| CN103725875B (en) | High-performance pellet | |
| CN103710536A (en) | Preparation method of pellet binder with high performance | |
| CN115874047A (en) | Fluxed pellet containing specularite and preparation method thereof | |
| CN103160687A (en) | Method for manufacturing crushing pellet sinter | |
| CN113333770B (en) | Preparation method of powder metallurgy iron powder | |
| CN101177731B (en) | Method for preparing sintered ore | |
| CN101643842A (en) | Method for strengthening oxidized pellet prepared by directly using sulfate slag | |
| CN103114198A (en) | Method for utilizing nickel flash smelting water-quenched slag | |
| CN111575479B (en) | Method for producing oxidized pellet by specularite | |
| CN103031430B (en) | Method for making sintering bed charge by returning mine at high mixture ratio | |
| CN112126778A (en) | Iron ore direct reduction metallurgy method based on 3D printing | |
| CN102628099B (en) | Method for forming balls by cooling and solidifying mineral powder by using water glass as bonding agent | |
| CN104498707B (en) | A kind of manufacture method of green pellets | |
| CN1037114C (en) | High-resistance high-activity charging stock for electric furnace and its producing method | |
| CN1621541A (en) | Process for preparing pellet from high-grade ironstone by using direct dry method | |
| CN110846497B (en) | Binder for magnesium-containing fluxed pellets and preparation method thereof | |
| CN117305581A (en) | Colloidal pellet binder and preparation and application thereof | |
| CN116532214B (en) | Method for applying iron ore powder on-line grinding to pellet production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |