CN116067835A - Blast furnace slag fluidity measuring device and method - Google Patents

Abstract

The invention provides a blast furnace slag fluidity measuring device and a method, and relates to the technical field of iron making. The device and the method can rapidly and accurately measure the fluidity of the blast furnace slag, provide reference basis for a blast furnace production site, compare the detection of the slag components of the blast furnace, measure the corresponding relation between the slag components and the fluidity of the slag, and promote the effective separation of slag iron.

Description

Blast furnace slag fluidity measuring device and method

Technical Field

The invention relates to the technical field of iron making, in particular to a blast furnace slag fluidity measuring device and method.

Background

In the blast furnace smelting process, slag fluidity is one of important indexes for measuring hearth activity, and is directly related to the separation effect of slag iron in a hearth and an iron tapping main channel outside the blast furnace. When the fluidity of the slag is poor, the slag iron is difficult to slag out of the blast furnace, the pressure of the blast furnace is suppressed, and the blast furnace is forced to reduce the wind; meanwhile, poor slag fluidity can cause difficult separation of slag and iron which are discharged from a hearth and enter the tapping main channel, iron and molten iron in slag are increased, the effective yield of metal iron is reduced, the effective utilization rate of resources is reduced, and the energy consumption is increased. For the blast furnace smelting of vanadium titano-magnetite, as the content of slag TiO2 is high, and high-melting-point titanium carbonitride is produced by easy over-reduction, the slag is wrapped outside iron beads in a dispersion form, so that the effective polymerization growth and sedimentation separation of the iron beads are prevented, meanwhile, the melting temperature of the medium-high titanium blast furnace slag is higher, the viscosity of the slag is easier to increase in the temperature drop process, the influence of the poor slag fluidity on the effective separation of slag iron is larger, the brought economic loss is larger, and the yield of metal vanadium is also reduced. The fluidity of the slag is mainly influenced by the temperature of the slag and the chemical composition of the slag, the fluidity of the slag is mastered in time, the furnace temperature control is optimized, the slag making system is optimized, and the method is very important for the stable and smooth running of the blast furnace and the optimization of the technical and economic indexes of the blast furnace.

Current methods of measuring slag fluidity include the application of rotary methods and steel die marking methods. The method comprises the steps of placing slag in a graphite or molybdenum crucible by using a rotating method to heat and melt, immersing a molybdenum measuring head connected with a molybdenum rod and a suspension wire into the slag, enabling the molybdenum measuring head to rotate in the slag at a constant rotating speed, enabling the slag to generate laminar flow under the rotating action of the measuring head, reacting the measuring head under the action of a speed gradient and a shearing force, enabling the suspension wire to generate torque, reacting copper sheets connected with the suspension wire, reading an included angle between the copper sheets through a photoelectric sensor, and finally converting the included angle into a viscosity value of the slag, so that the change of the viscosity value of the slag at different temperatures is used for representing the change of fluidity of the slag. The steel mould marking method uses a casting steel mould marked with scales to be horizontally placed on the ground, slag flows and solidifies under the action of gravity when the slag is poured into the casting steel mould, and the fluidity of the slag can be roughly represented through the flow length record of the slag.

However, the existing method for measuring the fluidity of the slag has certain defects, the measurement by using a rotating method is accurate, but is time-consuming and labor-consuming, the single temperature rise of a molten slag sample and the viscosity measurement take one day, the method is suitable for carrying out experimental study on the regularity of the viscosity of the slag by components, temperature and the like, the temperature of a blast furnace on a production site and the instability of the components of the slag are caused, the method is difficult to be applied to the production site to quickly and accurately judge the fluidity of the slag, the viscosity map such as isothermal and the like is constructed through a large number of component change experimental study to guide the production of the blast furnace, a large amount of experimental consumables, experimental expenses and detection force are consumed, and the method is also influenced by poor reproducibility of high Wen Shiyan. The method is simple, but is limited by environmental factors of a production site, the position where the steel mould is placed, the speed of scooping slag from a slag runner to pouring the slag into the steel mould by a measurer can greatly influence the fluidity of the slag, and the sampler can hardly sample and homogenize the slag at each time in the face of slag with the temperature of more than 1450 ℃. Therefore, the fluidity deviation measured by the method is larger, and the difference of the measurement results of different people is larger. Therefore, it is necessary to find a more convenient and effective slag fluidity measuring method with high accuracy and timely feed back the slag fluidity to the blast furnace production site.

Disclosure of Invention

According to the technical problem that the existing method for measuring the slag fluidity cannot accurately measure in a short time, the device and the method for measuring the slag fluidity of the blast furnace are provided, so that the effect of rapidly and effectively measuring the slag fluidity is achieved.

The invention adopts the following technical means:

a blast furnace slag fluidity measuring apparatus, comprising: the sampling tube and the vacuum pump that link to each other through coupling hose, sampling tube lower part is the cone, the outside cover of sampling tube is equipped with the stay tube, the sampling tube sets up in the slag runner top, stay tube upper portion links to each other with the sampling rod holder, the upper portion of sampling tube links to each other with coupling hose's one end, coupling hose's the other end links to each other with the air inlet valve of vacuum pump behind the vacuum pump gauge, be provided with the gas vent valve on the vacuum pump, vacuum pump gauge, the air inlet valve and the camera of vacuum pump and computer wireless connection.

Further, a square window for observing the slag height in the sampling tube is formed in the side face of the supporting tube, height scales are engraved on the supporting tube walls on two sides of the square window, and the camera is arranged on the outer side of the square window.

Further, a hollow layer for water cooling is arranged between the support tube and the sampling tube.

Further, the sampling tube is a quartz glass tube with the diameter of 20-30 mm.

Further, the sampling tube is erected in the supporting tube through a tube orifice horizontal boss arranged on the upper portion of the sampling tube.

Further, the outer wall of the sampling tube is carved with scale marks, and the positions of the scale marks are opposite to the square window.

Further, a settling tank with a trapezoid pit is built on the front-end slope gentle section of the slag runner, and the sampling pipe is arranged above the settling tank.

The invention also provides a blast furnace slag fluidity measuring method, which is realized based on the blast furnace slag fluidity measuring device and comprises the following steps:

separating slag iron by a skimming device, and enabling slag to enter a slag runner;

moving the support tube and the sampling tube to the upper part of the settling tank through the sampling rod clamping frame, and extending the front end of the sampling tube into the settling tank;

the computer sends a starting signal to the vacuum pump, the vacuum pump is started, so that negative pressure is formed in the sampling tube and the connecting hose, and slag can be sucked into the sampling tube and cannot be sucked to the uppermost end of the sampling tube;

an air inlet valve of the vacuum pump sends vacuum pump data to the computer, and a vacuum pump pressure gauge sends pressure data to the computer;

the computer sets a fluctuation critical value of a corresponding value as a sampling end point judging signal according to the vacuum pump data and the pressure data;

according to the sampling end point judging signal, controlling the vacuum pump to be closed, removing the sampling tube, and ending the sampling work;

and recording the height of the slag in the sampling tube, and judging the fluidity of different slag according to the height of the slag in the sampling tube, wherein the higher the fluidity of the slag is under the same negative pressure condition, the higher the height of the slag in the sampling tube is.

Further, the fluidity of the slag is inversely proportional to F resistance, the fluidity of the slag is directly proportional to h, and the height h of the slag in the sampling tube satisfies the following relation:

(P _{initial initiation} -P _t )*S _{Cross-sectional area} ＝mgh+1/2mv ² +F _{Resistance force}

Wherein: p (P) _{Initial initiation} At atmospheric pressure, P _t Is negative pressure S _{Cross-sectional area} For sampling tube cross-sectional area, F _{Resistance force} Is the upward friction resistance of slag.

Compared with the prior art, the invention has the following advantages:

according to the high titanium type blast furnace slag fluidity testing device and method provided by the invention, the slag fluidity is considered to be different, and the slag flowing resistance is different in the sampling process; the fluidity is different, and the melting temperature of the slag (inflection point of rapid increase of the viscosity of the slag, temperature lower than this temperature, rapid increase of the viscosity of the slag) is different; the fluidity of the slag is represented by testing the ascending height of the slag in the sampling tube under the same negative pressure condition, and the fluidity of the slag is correspondingly analyzed with the composition data and the physical temperature data of the slag, so that the relation between the composition of the slag, the physical temperature change and the fluidity of the slag can be further regressed. Through increasing the auxiliary cooling device in the sampling process, the slag cooling speed is increased, and the length of the sampling tube is greatly reduced. By the device and the method, the rapid test of the fluidity of the slag is realized, and the automatic judgment and stop of the end point of the test process are realized.

Drawings

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 the drawings without inventive effort to a person skilled in the art.

FIG. 1 is a block diagram of the apparatus of the present invention.

In the figure: 1. a sampling rod clamping frame; 2. a support tube; 3. a connecting hose; 4. a sampling tube; 5. slag runner; 6. a settling tank; 7. a camera; 8. a vacuum pump gauge; 9. an air inlet valve; 10. a vacuum pump; 11. a computer; 12. and an exhaust port valve.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be clear that the dimensions of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

As shown in fig. 1, the present invention provides a blast furnace slag fluidity measuring apparatus, comprising: the sampling tube 4 and the vacuum pump 10 that link to each other through coupling hose 3, sampling tube 4 lower part is the cone, sampling tube 4 outside cover is equipped with stay tube 2, the square window that is used for observing the slag height in the sampling tube 4 has been seted up to stay tube 2 side, carved with the altitude scale on the stay tube 2 wall of square window both sides, camera 7 sets up in the square window outside. The front end slope gentle section of the slag runner 5 is provided with a settling tank 6 with a trapezoid pit, and the sampling pipe 4 is arranged above the settling tank 6. The upper portion of the supporting tube 2 is connected with the sampling rod clamping frame 1, the upper portion of the sampling tube 4 is connected with one end of the connecting hose 3, the other end of the connecting hose 3 is connected with an air inlet valve 9 of a vacuum pump 10 after passing through a vacuum pump pressure gauge 8, an air outlet valve 12 is arranged on the vacuum pump 10, and the vacuum pump pressure gauge 8, the air inlet valve 9 of the vacuum pump 10 and the camera 7 are in wireless connection with a computer 11.

The invention also provides a blast furnace slag fluidity measuring method, which is realized based on the blast furnace slag fluidity measuring device and comprises the following steps:

the slag iron is separated by a skimming device, and slag enters a slag runner 5;

the supporting tube 2 and the sampling tube 4 are moved to the upper part of the sedimentation tank 6 through the sampling rod clamping frame 1, and the front end of the sampling tube 4 extends into the sedimentation tank 6;

the computer 11 sends a starting signal to the vacuum pump 10, the vacuum pump 10 is started, negative pressure is formed in the sampling tube 4 and the connecting hose 3, and the negative pressure value enables slag to be sucked into the sampling tube 4 and not sucked to the uppermost end of the sampling tube 4;

the air inlet valve 9 of the vacuum pump 10 sends vacuum pump data to the computer 11, and the vacuum pump pressure gauge 8 sends pressure data to the computer 11;

the computer 11 sets a fluctuation critical value of a corresponding value as a sampling end point judging signal according to the vacuum pump data and the pressure data;

and controlling the vacuum pump to be closed according to the sampling end point judging signal, removing the sampling tube 4, and ending the sampling work.

The specific scheme of the invention is as follows: the sampling rod clamping frame 1 clamps a hollow thin-wall sampling tube support tube 2 with circulating water cooling, one surface of the support tube 2 is provided with a rectangular square window, slag height in the sampling tube in the support tube is convenient to observe, and height graduated scales are marked on two sides of the rectangular square window to record slag height. A quartz glass tube is placed in the supporting tube 2 to serve as a sampling tube 4 (scale marks can be marked on the quartz glass tube under the condition that the precision is further pursued), the diameter of the quartz glass tube is 20-30mm, the lower end of the quartz glass tube is in a conical shape with slightly smaller diameter, the upper end of the quartz tube is provided with a horizontal protruding table, the quartz tube is conveniently and firmly placed at a supporting tube orifice with the inner diameter slightly larger than that of the quartz sampling tube, and if the quartz tube is provided with the scale marks, one side of the scale marks is aligned with a rectangular square window of the supporting tube 2. The upper end of the quartz tube is connected by a high-temperature-resistant connecting hose 3, and is connected with an air inlet valve 9 through a vacuum pump pressure gauge 8, under the action of a vacuum pump 10, negative pressure is formed in the sampling tube 4 and the connecting hose 3, the specific negative pressure value is to ensure that slag can be sucked into the sampling tube 4 but cannot be sucked to the uppermost end, and the negative pressure range value is obtained after experimental verification; the pressure gauge value and the vacuum pump signal are transmitted to the computer 11, and the computer 11 program automatically controls the vacuum pump 10 to work. In the process of slag iron tapping, slag iron is separated through a slag skimmer, slag enters a slag runner 5, a trapezoid pit is formed in a relatively gentle slope section at the front end of the slag runner to serve as a settling tank 6, the depth of slag liquid is deepened, meanwhile, the flow rate of the slag liquid is slowed down, and accurate sampling is facilitated. The front end of the sampling tube 4 extends into the sedimentation tank 6 (can be at a certain inclination angle), and slag liquid is sucked into the sampling tube 4 under the action of negative pressure. The rising height of slag liquid in the sampling tube is influenced by the cross-sectional area S of the sampling tube, the upward friction resistance F resistance of slag and the negative pressure Pt, the P is the atmospheric pressure initially, and the formula is expressed as follows:

(P _{initial initiation} -P _t )*S _{Cross-sectional area} ＝mgh+1/2mv ² +F _{Resistance force}

Under the same negative pressure condition, the better the fluidity of the slag, the smaller the F resistance, and the higher the slag suction height will be due to the small slag upward speed in the sampling process. Conversely, the worse the fluidity of the slag, the greater the slag upward resistance Fresistance, and the lower the slag suction height.

Along with the increase of negative pressure of the vacuum pump, the negative pressure value displayed by the pressure gauge 8 is gradually increased, the computer acquires and monitors the value in the pressure gauge 8 in real time, and when the negative pressure value reaches the set constant negative pressure value, the negative pressure value is used as a sampling end point judging signal, and the sampling work is ended. In the sampling process, the camera system 7 aligned with the rectangular window of the support tube 2 records the height of slag in the sampling tube by comparing with a graduated scale, and transmits the height into the computer 11, and the height value is recorded in the computer through image recognition processing and is correspondingly recorded with the iron number of the production site. The recorded slag height data corresponds to the chemical components of the blast furnace slag in the production site and the temperature values measured by the molten iron temperature measuring system one by one, so that the influence relationship of the chemical components of the slag and the temperature of the slag iron on the slag fluidity represented by the slag height values of the system is obtained on the basis of accumulation and regression analysis of data samples, and the blast furnace production is guided according to the measured slag fluidity.

In the sampling work, under the cooling effect of the sampling support tube 2 outside the sampling tube 4, the temperature of the slag in the sampling tube 4 is quickly reduced in the rising process, the viscosity of the slag is increased, the upper end starts to solidify, the upward resistance F resistance of the slag is increased, and at the moment, the height that the slag in the sampling tube can reach is lower under the same negative pressure condition. Therefore, the cooling device is added outside the sampling tube, so that the required height of the sampling tube can be greatly shortened, and the slag is not easy to be sucked into the uppermost end of the sampling tube under the condition of limited sampling tube height; the cooling water flow is fixed in the whole process, and the treated soft water is adopted for cooling, so that the adverse effect of scaling on the cooling effect is avoided. The whole sampling process is completed by the up-and-down movement of the sampling rod clamping frame 1 and the linkage of the horizontal sliding device connected with the sampling rod clamping frame 1.

Examples

A blast furnace taking high titanium type vanadium titano-magnetite as a main production raw material has high content of slag TiO2 and high content of metallic iron in slag, so that a trapezoid sedimentation pit is arranged in a slag runner to promote secondary sedimentation and collection of iron in slag. The TiO2 content in the slag is up to more than 20%, and the slag cannot be used as production raw materials of cement and the like, is not subjected to water slag flushing treatment, flows to a slag tank through a slag runner, and has the application conditions of the method. Under the negative pressure of-40 KPa, a sampling experiment is carried out by adopting a quartz glass tube with the diameter of 20mm and the length of 1500mm as a sampling tube and under the protection of a supporting tube of the sampling tube with the diameter of 23mm and water cooling, the temperature fluctuation (1420-1460 ℃) of slag iron and the fluctuation (R2: 1.05-1.13, tiO2: 20.5-23%, mgO: 7.5-9%, al2O3: 13.2-15%) of slag component are recorded by a camera device, and the slag height in the quartz tube fluctuates between 500mm-900 mm. Because the high titanium blast furnace slag has higher melting temperature and short slag property, under the temperature drop effect, the slag at the upper end of the sampling tube has obvious viscosity increase and solidification phenomenon under the cooling effect. By combining data sample analysis, the height of the slag in the sampling tube is obviously reduced along with the reduction of the temperature value of slag iron, is obviously reduced along with the increase of slag R2, is reduced along with the increase of slag TiO2, is slightly reduced along with the increase of the content of MgO and Al2O3, and can accurately reflect the influence of temperature change and slag component change on slag fluidity.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (9)

1. A blast furnace slag fluidity measuring apparatus, comprising: sampling tube (4) and vacuum pump (10) that link to each other through coupling hose (3), sampling tube (4) lower part is the cone, sampling tube (4) outside cover is equipped with stay tube (2), sampling tube (4) set up in slag runner (5) top, stay tube (2) upper portion links to each other with sampling rod holder (1), the upper portion of sampling tube (4) links to each other with coupling hose (3) one end, coupling hose (3) the other end links to each other with air inlet valve (9) of vacuum pump (10) behind vacuum pump meter pressure table (8), be provided with exhaust port valve (12) on vacuum pump (10), air inlet valve (9) and camera (7) of vacuum pump meter pressure table (8), vacuum pump (10) and computer (11) wireless connection.

2. The blast furnace slag fluidity measurement device according to claim 1, wherein square windows for observing the slag height in the sampling tube (4) are arranged on the side surfaces of the supporting tubes (2), height scales are carved on the walls of the supporting tubes (2) on the two sides of the square windows, and the camera (7) is arranged on the outer sides of the square windows.

3. The blast furnace slag fluidity measuring device according to claim 1, wherein a hollowed-out layer for water cooling is arranged between the supporting tube (2) and the sampling tube (4).

4. The blast furnace slag fluidity measuring device according to claim 1, wherein the sampling tube (4) is a quartz glass tube having a diameter of 20-30 mm.

5. The blast furnace slag fluidity measuring device according to claim 1, wherein the sampling tube (4) is erected inside the supporting tube (2) through a tube orifice horizontal boss provided at an upper portion of the sampling tube (4).

6. The blast furnace slag fluidity measuring device according to claim 2, wherein the outer wall of the sampling tube (4) is carved with a scale mark, and the position of the scale mark is opposite to the square window.

7. The blast furnace slag fluidity measuring device according to claim 1, wherein a settling tank (6) with a trapezoid pit is built in the front slope flat section of the slag runner (5), and the sampling tube (4) is arranged above the settling tank (6).

8. A blast furnace slag fluidity measuring method, realized based on the blast furnace slag fluidity measuring device according to claims 1 to 7, characterized by comprising the steps of:

slag iron is separated by a skimming device, and slag enters a slag runner (5);

the supporting tube (2) and the sampling tube (4) are moved to the upper part of the sedimentation tank (6) through the sampling rod clamping frame (1), and the front end of the sampling tube (4) extends into the sedimentation tank (6);

the computer (11) sends a starting signal to the vacuum pump (10), the vacuum pump (10) is started, negative pressure is formed in the sampling tube (4) and the connecting hose (3), and slag can be sucked into the sampling tube (4) and cannot be sucked to the uppermost end of the sampling tube (4) due to the negative pressure value;

an air inlet valve (9) of a vacuum pump (10) sends vacuum pump data to a computer (11), and a vacuum pump pressure gauge (8) sends pressure data to the computer (11);

the computer (11) sets a fluctuation critical value of a corresponding value as a sampling end point judging signal according to the vacuum pump data and the pressure data;

according to the sampling end point judging signal, controlling the vacuum pump to be closed, moving out the sampling tube (4), and ending the sampling work;

the height of the slag in the sampling tube (4) is recorded, and the higher the fluidity of the slag is under the same negative pressure condition, the higher the height in the sampling tube (4) is, and the fluidity of different slag is judged by the height of the slag in the sampling tube (4).

9. The blast furnace slag fluidity measurement method according to claim 8, wherein: the fluidity of the slag is inversely proportional to F resistance, the fluidity of the slag is directly proportional to h, and the height h of the slag in the sampling tube (4) meets the following relation:

(P _{initial initiation} -P _t )*S _{Cross-sectional area} ＝mgh+1/2mv ² +F _{Resistance force}

Wherein: p (P) _{Initial initiation} At atmospheric pressure, P _t Is negative pressure S _{Cross-sectional area} For sampling tube cross-sectional area, F _{Resistance force} Is the upward friction resistance of slag.

Images