阅读说明：本技术 基于纯试剂模拟的烧结体的制备及高温铺展范围测定方法 (Method for preparing sintered body based on pure reagent simulation and measuring high-temperature spreading range ) 是由 翟晓波 王刚 吴开基 何茂成 李牧明 于 2021-01-28 设计创作，主要内容包括：本发明涉及一种基于纯试剂模拟的烧结体的制备及高温铺展范围测定方法,属于铁矿粉烧结技术领域。将赤铁矿柱体、铁酸一钙柱体从上到下依次置于柱形的纯试剂混合物基底的表面正中心上后进行烧结,铁酸一钙柱体高温熔化后形成的熔体,通过化学反应将位于其上层的赤铁矿柱体和位于其下层的纯试剂混合物的柱体基底,黏结起来成为基于纯试剂模拟的烧结体。待烧结体冷却后,采集烧结体的俯视图片,获得烧结体的高温铺展面积,高温铺展面积占纯试剂混合物的柱体底面积的百分比,即为烧结体的高温铺展范围。本发明解决了现有烧结体结构偏离实际烧结生产、由于基底成分复杂而无法考察脉石含量影响的技术问题,从而为铁矿粉烧结的矿种优选提供依据。(The invention relates to a method for preparing a sintering body based on pure reagent simulation and measuring a high-temperature spreading range, and belongs to the technical field of iron ore powder sintering. And (2) placing the hematite column and the monocalcium ferrite column on the surface center of the cylindrical pure reagent mixture substrate from top to bottom in sequence, and sintering, wherein a melt formed by melting the monocalcium ferrite column at high temperature bonds the hematite column on the upper layer and the pure reagent mixture column substrate on the lower layer through chemical reaction to form a sintered body based on pure reagent simulation. And after the sintered body is cooled, collecting a top view picture of the sintered body to obtain a high-temperature spreading area of the sintered body, wherein the percentage of the high-temperature spreading area to the bottom area of the column of the pure reagent mixture is the high-temperature spreading range of the sintered body. The invention solves the technical problems that the structure of the existing sintered body deviates from the actual sintering production and the influence of the gangue content cannot be inspected due to the complex substrate components, thereby providing a basis for the optimization of ore types sintered by iron ore powder.)

1. A preparation method of a sintered body based on pure reagent simulation is characterized by comprising the following steps:

placing the hematite column and the calcium ferrite column on the end face of the cylindrical pure reagent mixture substrate in sequence to form a combination body, wherein the calcium ferrite column is placed between the hematite column and the pure reagent mixture substrate;

and sintering the combination, wherein the hematite column and the pure reagent mixture substrate are bonded by a melt formed by melting the monocalcium ferrite column at high temperature to form a sintered body based on pure reagent simulation.

2. The method of claim 1, wherein the method comprises the steps of: the hematite column, the ferrous acid-calcium column and the pure reagent mixture substrate are all cylinders and are coaxially arranged.

3. The method of claim 2, wherein the method comprises the steps of: the diameter of the hematite column body is 8-10 mm, and the height of the hematite column body is 6-8 mm; the diameter of the calcium ferrite cylinder is 8-10 mm, and the height of the calcium ferrite cylinder is 6-8 mm; the diameter of the pure reagent mixture substrate is 20-30 mm, and the height is 10-15 mm.

4. The method of claim 1, wherein the method comprises the steps of: the hematite column is formed by pressing hematite powder with the diameter not more than 0.074 mm.

5. The method of claim 1, wherein the step of preparing a sintered body based on pure reagent simulation,

the preparation of the calcium ferrite cylinder comprises the following steps: mixing CaO reagent with Fe₂O₃The reagent is prepared according to the following steps of: 74, preparing the mixture into a cylinder with the diameter of 20-30 mm and the height of 10-20 mm, calcining the cylinder, preparing the calcined cylinder into powder with the particle size of less than 0.074mm, and then pressing and forming the powder again.

6. The method for preparing a sintered body based on pure reagent simulation as claimed in claim 5, wherein the calcination system of the monocalcium ferrite cylinder is that under the whole air condition, the room temperature → 900 ℃ → 900 ℃ → 1200 ℃, the corresponding time periods are respectively 100min, 50min, 30min and 500min, the heating furnace is powered off after the 1200 ℃ heat preservation is finished, and the monocalcium ferrite cylinder is cooled along with the furnace.

7. The method of claim 1, wherein the preparation of the pure reagent mixture substrate comprises the steps of: mixing Fe₂O₃Reagent, SiO₂Reagent, CaO reagent, and Al₂O₃And uniformly mixing the reagent and the MgO reagent according to the mass ratio of the uniformly mixing scheme, and then pressing and forming.

8. The method of claim 1, wherein the method comprises the steps of: the mass ratio of the Fe2O3 reagent in the blending scheme is 89-98 percent, and the SiO₂The mass ratio of the reagent is 0-8%, the mass ratio of the CaO reagent is 0-1%, and Al₂O₃The mass ratio of the reagent is 0-4%, and the mass ratio of the MgO reagent is 0-1%.

9. The method for preparing a sintered body based on pure reagent simulation as claimed in claim 1, wherein the temperature system of sintering is as follows:

under the whole air condition, the temperature is room temperature → 600 ℃ → 1000 → 1150 → 1280 ℃ → 1150 → 1000 ℃, the corresponding time periods are 4min, 1min, 1.5min, 1min, 4min, 1.5min, 2min respectively, and the furnace is followed by air cooling to the room temperature after the temperature is 1000 ℃.

10. A method for measuring the high-temperature spreading range of a sintered body based on pure reagent simulation is characterized by comprising the following steps: after the sintered body based on the pure reagent simulation prepared by the method of any one of claims 1 to 9 is cooled, a top view of the sintered body based on the pure reagent simulation is collected, an image analysis software is used for defining a spreading edge of a high-temperature melt, and a high-temperature spreading area of the sintered body based on the pure reagent simulation is obtained, wherein the percentage of the high-temperature spreading area to the end surface area of the pure reagent mixture substrate is the high-temperature spreading range of the sintered body based on the pure reagent simulation.

Technical Field

The invention belongs to the technical field of iron ore powder sintering, and relates to a method for preparing a sintering body based on pure reagent simulation and measuring a high-temperature spreading range.

Background

The high-temperature melt consolidation is the main consolidation mode of iron ore powder sintering. The iron ore powder, the flux, the solid fuel and other particles are granulated under the action of water to form quasi-particles with certain cold strength. The core of the pseudo-particle is nuclear ore particle with larger particle size, and the adhesion powder layer is iron ore powder and flux particle with smaller particle size. Along with the rapid temperature rise in the sintering material layer, solid phase reaction occurs in the adhesion powder layer. The resulting low melting mineral melts at a higher temperature to form a high temperature melt with some spreading ability. The high temperature melt bonds with the adjacent core ore to form a sintered body. The sintered body in the material layer is further solidified to become sintered ore.

The prior sintered body structure is mainly embodied as the following two types: firstly, an iron ore powder cylinder is positioned on the upper surface of a CaO pure reagent cylinder, and the assimilation temperature represents the capability of the iron ore powder and a flux to react to generate a melt; secondly, the high-temperature melt and a substrate such as specific gangue minerals, iron ore powder or return ores and the like respectively form a sintered body, and the permeation behavior of the high-temperature melt to the inside of the substrate is represented by the permeation depth and the permeation volume index. However, the sintered body structure involved in the above studies only considered the effect of the high temperature melt on the high temperature spread range of the sintered body from the substrate vertically below, neglecting the effect of the presence of the core ore above the high temperature melt. Further, the base of the sintered body is not a simple gangue mineral, but an iron ore powder with a complicated composition, and the influence of the base gangue component on the high-temperature spreading range of the sintered body cannot be scientifically examined.

Therefore, the sintered body close to a real structure is constructed, and the influence of the content of the base gangue on the high-temperature spreading range of the sintered body is examined on the basis of pure reagent simulation, so that the method has important significance for understanding the structure of the sintered ore and optimizing the ore blending technology.

Disclosure of Invention

In view of the above, the invention aims to provide a method for preparing a sintered body based on pure reagent simulation and measuring a high-temperature spreading range, which mainly solves the technical problems that the structure of the conventional sintered body deviates from the actual sintering production and the influence of gangue content cannot be examined due to complex substrate components, so that a basis is provided for optimizing the ore type sintered by iron ore powder.

In order to achieve the purpose, the invention provides the following technical scheme:

a method for preparing a sintered body based on pure reagent simulation comprises the following steps:

placing the hematite column and the calcium ferrite column on the end face of the cylindrical pure reagent mixture substrate in sequence to form a combination body, wherein the calcium ferrite column is placed between the hematite column and the pure reagent mixture substrate; and sintering the combination, wherein the melt formed after the monocalcium ferrite cylinder is melted at high temperature bonds the hematite cylinder at the upper layer and the pure reagent mixture substrate at the lower layer to form a sintered body based on pure reagent simulation.

Optionally, the hematite column, the monocalcium ferrite column and the pure reagent mixture substrate are all cylinders, and the hematite column, the monocalcium ferrite column and the pure reagent mixture substrate are coaxially arranged.

Optionally, the diameter of the hematite column is 8-10 mm, and the height is 6-8 mm; the diameter of the calcium ferrite cylinder is 8-10 mm, and the height of the calcium ferrite cylinder is 6-8 mm; the diameter of the pure reagent mixture substrate is 20-30 mm, and the height is 10-15 mm.

Optionally, the hematite column is formed by pressing hematite powder with a diameter of no more than 0.074 mm.

Optionally, the preparation of the monocalcium ferrite cartridge comprises the following steps: mixing CaO reagent with Fe₂O₃The reagent is prepared according to the following steps of: 74, preparing the mixture into a cylinder with the diameter of 20-30 mm and the height of 10-20 mm, calcining the cylinder, preparing the calcined cylinder into powder with the particle size of less than 0.074mm, and then pressing and forming the powder again.

Alternatively, the calcination regime for the monocalcium ferrite cartridge is: under the air condition in the whole process, the room temperature → 900 → 1200 ℃ → 1200 ℃, the corresponding time periods are 100min, 50min, 30min and 500min respectively, the heating furnace is powered off after the heat preservation at 1200 ℃, and the monocalcium ferrite column is cooled along with the furnace.

Alternatively, the preparation of the pure reagent mixture substrate comprises the following steps: mixing Fe₂O₃Reagent, SiO₂Reagent, CaO reagent, and Al₂O₃And uniformly mixing the reagent and the MgO reagent according to the mass ratio of the uniformly mixing scheme, and then pressing and forming.

Optionally, the mass ratio of the Fe2O3 reagent in the blending scheme is 89-98%, and SiO is₂The mass ratio of the reagent is 0-8%, the mass ratio of the CaO reagent is 0-1%, and Al₂O₃The mass ratio of the reagent is 0-4%, and the mass ratio of the MgO reagent is 0-1%.

Optionally, the temperature regime for sintering is: under the whole air condition, the temperature is room temperature → 600 ℃ → 1000 → 1150 → 1280 ℃ → 1150 → 1000 ℃, the corresponding time periods are 4min, 1min, 1.5min, 1min, 4min, 1.5min, 2min respectively, and the furnace is followed by air cooling to the room temperature after the temperature is 1000 ℃.

After the sintered body prepared by the method is cooled, a overlooking picture of the sintered body based on the pure reagent simulation is collected, the spreading edge of a high-temperature melt is defined by using image analysis software, and the high-temperature spreading area of the sintered body based on the pure reagent simulation is obtained, wherein the percentage of the high-temperature spreading area to the end surface area of a pure reagent mixture substrate is the high-temperature spreading range of the sintered body based on the pure reagent simulation.

The invention has the beneficial effects that:

1) the sintering body based on pure reagent simulation adopted by the method is formed by sintering the monocalcium ferrite cylinder and the upper and lower cylinders, the influence of surrounding nuclear ores on a high-temperature melt is fully considered, and the structure of the existing sintering body is perfected;

2) the method of the invention takes various pure reagent mixtures as the substrate, and can simulate the condition that the high-temperature melt is contacted with the surrounding nuclear ore to inspect SiO in the substrate₂、Al₂O₃The influence of the isopiemite content on the high-temperature spreading range of the sintered body.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is an XRD pattern of monocalcium ferrite in the present invention.

Fig. 2 is a schematic representation of a sintered body structure and its high temperature spreading based on pure reagent simulation.

Fig. 3 is a top view of a sintered body high temperature spreading based on pure reagent simulation.

FIG. 4 shows SiO in the substrate₂The rule of the influence of the pure reagent proportion on the high-temperature spreading range of the sintered body is determined;

FIG. 5 shows Al in the substrate₂O₃The influence rule of the pure reagent proportion on the high-temperature spreading range of the sintered body.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Table 1 shows the main chemical composition (in weight percent) of hematite ore of the examples of the present invention. Hematite is prepared into powder with the grain diameter of less than 0.074mm, and then 0.5g of the powder is pressed into cylinders with the diameter of 8mm by 6mm by a sample press.

Table 1 main chemical composition of hematite of the examples of the invention, in units: weight percent of

Mixing analytically pure CaO reagent with Fe₂O₃The reagent is prepared according to the following steps of: 74, mixing uniformly in a mixing device, pressing the mixed powder into a cylinder with phi 20mm x 10mm by a press machine, and calcining in a heating furnace. The calcination system is as follows: under the air condition in the whole process, the room temperature → 900 → 1200 ℃ → 1200 ℃, the corresponding time periods are 100min, 50min, 30min and 500min respectively, the heating furnace is powered off after the heat preservation at 1200 ℃, and the monocalcium ferrite is cooled along with the furnace.

Taking out the cooled monocalcium ferrite sample, preparing powder with the particle size of less than 0.074mm, and pressing 0.5g of monocalcium ferrite powder into a cylinder with the diameter of 8mm by 6mm by a sample press. The XRD pattern of the monocalcium ferrite powder is shown in figure 1. By comparing PDF standard cardsSo that the calcium ferrite powder is completely CaFe₂O₄The mineral meets the test requirements.

Table 2 shows the blending scheme of the pure reagents. Reference scheme Fe in Base₂O₃、SiO₂、CaO、Al₂O₃The proportions of the MgO pure reagent were 93.80%, 4.00%, 0.10%, 2.00%, and 0.10%, respectively. On the basis of the above, SiO₂The proportion of pure reagents is changed up and down at intervals of 2 percent, and the rest pure reagents are reversely adjusted according to the respective proportion to respectively obtain S series schemes S0, S2, S6 and S8; make Al₂O₃The proportion of pure reagents is changed up and down at intervals of 1 percent, and the rest pure reagents are reversely adjusted according to the respective proportion, thus obtaining A series schemes A0, A1, A3 and A4 respectively. According to the mass ratio in various blending schemes shown in Table 2, Fe₂O₃、SiO₂、CaO、Al₂O₃And MgO and other pure reagents are mixed in a mixing device, and 3.5g of mixed powder is pressed into cylinders with phi 20mm x 10mm by a press molding machine.

Table 2 pure reagent mixing scheme of the present invention, unit: weight percent of

Placing a monocalcium ferrite cylinder and a hematite cylinder on the positive center of the upper surface of a cylinder base of each pure reagent mixture in sequence, and sintering the cylinders by using a heating furnace to prepare a sintered body based on pure reagent simulation. As shown in fig. 2, the sintered body based on the pure reagent simulation is formed by bonding a hematite column located at the upper layer thereof and substrates of various pure reagent mixtures located at the lower layer thereof through physical and chemical reactions from a melt formed by high-temperature melting of monocalcium ferrite. The temperature system is as follows: under the condition of air in the whole process, the temperature is room temperature → 600 ℃ → 1000 → 1150 → 1280 ℃ → 1150 → 1000 ℃, the corresponding time periods are 4min, 1min, 1.5min, 1min, 4min, 1.5min and 2min respectively, the heating furnace is powered off after the temperature is 1000 ℃, and the sintered body based on the pure reagent simulation is air-cooled to the room temperature.

After the sample is cooled, a top view (as shown in fig. 3) of the sintered body based on the pure reagent simulation is collected, the spreading edge of the high-temperature melt is defined by using image analysis software, and the high-temperature spreading area of the sintered body based on the pure reagent simulation is obtained. The bottom area of the column for each pure reagent mixture was also determined using image analysis. The percentage of the high-temperature spreading area to the bottom area of the cylinder of each pure reagent mixture is the high-temperature spreading range of the sintered body based on the pure reagent simulation.

Table 3 shows the high temperature spread range of the sintered body based on pure reagent simulation.

Table 3 high temperature spreading range of sintered body based on pure reagent simulation

Based on the data in tables 2 and 3, the relationship graphs shown in fig. 4 and 5 can be plotted, respectively. As can be seen from the figure, SiO in the substrate with the pure reagent mixture₂Ratio of reagents, Al₂O₃The rising of the reagent proportion shows the expansion trend of the high-temperature spreading range of the sintered body simulated based on the pure reagent. Comparing the slope of the fitted curves in FIGS. 4 and 5 with the R2 value, it can be seen that Al is compared with Al₂O₃Reagent, SiO₂The effect of the reagent on the high temperature spreading range of the sintered body based on pure reagent simulation is more remarkable. Thus, the SiO of the gangue in the substrate is obtained₂Content and Al₂O₃And (3) the influence rule of the content on the high-temperature spreading range of the sintered body based on pure reagent simulation.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.