TW201807408A - Method for measuring solidification temperature of slag during temperature rising process obtaining the solidification temperature of the slag by shaping the slag and observing change of shape during the temperature rising process - Google Patents

Abstract

A method for measuring solidification temperature of slag during temperature rising process includes the following steps: heating and melting slag powders and oxide composition powders of magnesium oxide, aluminum oxide, calcium oxide, silicon dioxide and titanium dioxide after mixing; cooling the melting product to form slag block; grinding the slag block into powder to obtain a powder sample; mixing the powder sample, water and adhesive to form a cylinder sample; heating the cylinder sample to observe change of shape of the cylinder sample during the heating process; and setting a temperature of the cylinder sample starting to deform as a solidification temperature of the slag. The method obtains the solidification temperature of the slag by shaping the slag and observing change of shape during the temperature rising process. The obtained solidification temperature can precisely represent fluidity of the slag.

Description

Method for measuring curing temperature during slag heating

The present invention relates to a measurement method for slag fluidity, and particularly to a measurement method for directly observing the morphological change of slag during the heating process by an observation method to obtain the solidification temperature of the slag, and then accurately know the slag fluidity.

Slag is a product obtained by smelting and separating high temperature impurities from metals in various pyrometallurgical processes. The slag fluidity at high temperature is a very important property. The slag has good fluidity and can be smoothly separated from the metal, and at the same time, it provides good kinetic conditions for the reaction of removing impurities in the metal. Therefore, how to accurately control the fluidity of slag is an extremely important subject in the field of metallurgy.

The existing method for controlling the fluidity of the slag is to measure the melting temperature of the slag, and the melting temperature is performed in a cooling manner and obtained by a viscosity analysis method. The melting temperature is the temperature at which the viscosity suddenly rises sharply. As far as the material structure of the cooling process is concerned, it should be almost completely solidified, and the rotor torque of the viscometer will suddenly increase. Melting temperature has not been defined by standard specifications in metallurgical science. There is no given range for measuring viscosity and temperature. Currently, three methods are used to define the fixed slope method, the fixed viscosity method and the intersection of two tangents. However, none of the above three methods can accurately define the melting temperature, resulting in a problem that the fluidity cannot be accurately controlled when the slag fluidity control is performed according to the defined melting temperature.

As can be seen from the above description, the measurement of the melting temperature cannot accurately control the slag fluidity, so there is still a need to develop a method that can more simply and accurately control the slag fluidity.

Therefore, an object of the present invention is to provide a method for determining a curing temperature during a slag heating process, which includes the following steps:

Therefore, the method for measuring the curing temperature in the slag heating process according to the present invention includes the following steps: slag powder and an oxide composition powder containing magnesium oxide, aluminum oxide, calcium oxide, silicon dioxide, and titanium dioxide are mixed and heated to melt, and then The molten product is cooled and formed into a slag block, and the slag block is ground into powder to obtain a powder sample; the powder sample, water and a binder are mixed to form a block to obtain a column sample; and heating For the pillar sample, the shape change of the pillar sample during the heating process was observed, and the deformation temperature when the shape of the pillar sample started to change was taken as the solidification temperature of the slag.

The effect of the present invention is that the method for measuring the curing temperature during the slag heating process obtains the slag curing temperature by forming the slag into a block and directly observing its morphological change during heating. The obtained curing temperature can be presented more accurately. The slag fluidity is more conducive to controlling the slag fluidity.

The following will describe the content of the present invention in detail:

Preferably, the temperature at which the shape of the column sample changes to a semi-circular body during heating is taken as the liquefaction temperature of the slag.

Preferably, the temperature at which the column sample starts to flow during the heating process is taken as the flow temperature of the slag.

Preferably, the heating is performed at a rate of 10 ° C / min to 1500 ° C.

Preferably, the average particle size of the powder sample ranges from 50 μm to 100 μm.

Preferably, the average particle size of the slag powder ranges from 50 μm to 100 μm.

Preferably, the average particle diameter of the oxide composition powder ranges from 50 μm to 75 μm.

Preferably, the slag is the final slag of the blast furnace. The final slag of the blast furnace contains CaO, SiO ₂ , Al ₂ O ₃ , MgO, and TiO ₂ .

By adding the oxide composition, a slag having a desired chemical composition is configured. Preferably, the oxide composition contains magnesium oxide, aluminum oxide, calcium oxide, silicon dioxide, and titanium dioxide. The total content of the oxide composition is 100 wt%, and the content of the magnesium oxide ranges from 3 to 11 wt%. The total content of the oxide composition is 100 wt%, and the content of the alumina ranges from 10 to 18 wt%. The total content of the oxide composition is 100 wt%, and the content of the calcium oxide ranges from 39 to 46 wt%. The total content of the oxide is 100 wt%, and the content of the silicon dioxide ranges from 32 to 41 wt%. The total content of the oxide is 100 wt%, and the content of the titanium dioxide ranges from 0.3 to 4.5 wt%.

Preferably, the cylindrical sample is a cylindrical sample with a diameter of 3.5 cm and a height of 3.5 cm.

Preferably, the binding agent is starch. Preferably, the total amount of the powder sample, water and starch is 100 wt%, the amount of the powder sample is in the range of 70 to 77 wt%, the amount of water is in the range of 20 to 25 wt%, and the amount of the starch is 3 to 5 wt%.

The present invention will be further described with reference to the following examples, but it should be understood that this example is for illustrative purposes only and should not be construed as a limitation on the implementation of the present invention.

[Example 1]

The final slag of the blast furnace obtained at the steelmaking site is first ground into a fine powder with an average particle size ranging from 50 μm to 100 μm, and then with an oxide composition powder with an average particle size ranging from 50 μm to 75 μm (containing 39 to 46 wt% of CaO, 3 to 11 wt% of MgO, 10 to 18 wt% of Al ₂ O _3, 32 to 41wt% of SiO ₂ and 0.3 to 4.5wt% of TiO ₂₎ are mixed into a high-temperature furnace at 1550 deg.] C The mixture is heated and melted, and the molten product is taken out of the high-temperature furnace to be cooled into a block to obtain a slag block. The slag block was crushed and ground into powder to obtain a powder sample with an average particle size range of 75 μm, and the component analysis of the powder sample to be tested was performed by an inductively coupled plasma atomic emission spectrometer (ICP-AES). . The powder sample, water and starch (powder sample 70 to 77 wt%, water: 20 to 25 wt%, starch: 3 to 5 wt%) were mixed and pressed into a block to form a cylindrical sample (3.5 cm in diameter). , Height 3.5 cm). The cylindrical sample was heated in a furnace tube of a high temperature furnace (German dataphysis company, model: OCA 15LHT plus). The heating method was heated to 1500 ° C at a rate of 10 ° C / min, and a high temperature was used during the heating and heating process. An optical image capture device (dataphysis, Germany, model: OCA 15LHT plus) captures the shape change of the cylindrical sample as the temperature rises. Among them, FIG. 1A is a photograph of the cylinder before the heating has started; FIG. 2A is a photograph of the shape of the cylinder sample when the heating process has just started to change, and the temperature at this time is called the deformation temperature; 3A is a photograph when the shape of the cylindrical sample becomes a semicircular body during the heating process, and the temperature at this time is called a liquidus temperature (liquidus temperature); FIG. 4A is a photograph when the cylindrical sample starts to flow during the heating process, The temperature at this time is called the flow temperature

[Examples 2 to 31]

Examples 2 to 31 were performed in the same step flow as Example 1, except that different oxide composition powders were used.

The measurement results of the deformation temperatures of Examples 1 to 31 are shown in Tables 1 to 5.

[Measure the melting temperature with a known viscosity analysis method]

The powder samples of Examples 1 to 31 were subjected to a viscosity analysis method to obtain a curve of viscosity as a function of temperature. The tangent lines at both ends of the curve were taken, and the intersection of the two tangent lines was used as the melting temperature. The flow temperature, the temperature at which the viscosity suddenly rises sharply), and the obtained melting temperature is compared with the deformation temperature obtained in Examples 1 to 31. The steps of the viscosity analysis method are as follows: pour 110 grams of powder sample into a graphite crucible, and then place the graphite crucible in a high temperature slag viscosity measuring instrument (manufacturer: BROOKFIELD, model: MODEL DV-II) On the sample holder, the crucible is lifted into an upright high-temperature furnace by a lifting device to be heated until the powder sample in the crucible is completely melted, and then the torque viscometer is lowered to the position by the lifting device, and the viscosity measurement with temperature is performed. Measurement, and at the same time to obtain the data of the torque increase with time and the temperature decrease with time, the curve of the change of viscosity with temperature is obtained by comparing the correction curve of torque and viscosity. The measured melting temperatures of Examples 1 to 31 are shown in Tables 1 to 5.

Table 1

Table 2

table 3

Table 4

table 5

As can be seen from Tables 1 to 5, the difference between the deformation temperature and the melting temperature of Examples 1 to 31 is between 0 and 36 ° C. Therefore, the deformation temperature can be regarded as the solidification temperature of the slag.

In summary, the method for measuring the slag fluidity of the present invention obtains the slag solidification temperature by forming the slag into pieces and directly observing the morphological changes during heating. The solidification temperature obtained can accurately represent the slag's temperature. Liquidity, so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited in this way, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are still Within the scope of the invention patent.

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: [Fig. 1A] is a photograph of a cylindrical sample of Embodiment 1 of the method for measuring slag fluidity of the present invention; Fig. 1B] is a grid diagram corresponding to the photograph of Fig. 1A; [Fig. 2A] is a photograph of the cylindrical sample of the first embodiment when the shape of the sample has just started to change; [Fig. 2B] is a grid corresponding to the photograph of Fig. 2A [Fig. 3A] is a photograph of the cylindrical sample of Example 1 when the shape becomes a semi-circular body during heating [Fig. 3B] is a grid diagram corresponding to the photograph of Fig. 3A; [Fig. 4A] is Example 1 A photo of the cylindrical sample at the beginning of the flow during heating; and [Fig. 4B] is a graph corresponding to the photo of Fig. 4A.

Claims (7)

A method for measuring the curing temperature during the slag heating process includes the following steps: mixing and heating and melting the slag powder and an oxide composition powder containing magnesium oxide, aluminum oxide, calcium oxide, silicon dioxide, and titanium dioxide, and then heating and melting The obtained product is cooled and formed into a slag block, and the slag block is ground into powder to obtain a powder sample; the powder sample, water and a binder are mixed to form a block to obtain a column sample; and the column is heated; At the same time, observe the shape change of the pillar sample during the heating process, and the deformation temperature when the shape of the pillar sample starts to change is used as the solidification temperature of the slag. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the heating method is to raise the temperature to 1500 ° C at a rate of 10 ° C / min. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the average particle size of the powder sample ranges from 50 μm to 100 μm. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the average particle diameter of the slag powder ranges from 50 μm to 100 μm. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the average particle diameter of the oxide composition powder ranges from 50 μm to 75 μm. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the slag is a final slag of a blast furnace. The method for measuring a curing temperature in a slag heating process according to claim 1, wherein the cylindrical sample is a cylindrical sample having a diameter of 3.5 cm and a height of 3.5 cm.