阅读说明：本技术 石膏胶凝材料凝结硬化时间检测方法 (Method for detecting setting and hardening time of gypsum cementing material ) 是由 黄滔 刘翔 邱峰 傅强 任雨 胡秀华 李静芯 张蒙 于 2021-07-22 设计创作，主要内容包括：本发明提供了一种石膏胶凝材料凝结硬化时间检测方法,该方法包括：步骤S1,连续检测石膏胶凝材料凝结硬化时的表面白度值数据,记录形成表面白度值数据序列；步骤S2,根据记录的所述表面白度值数据序列,计算序列的差分值,以所述差分值绘制曲线图；步骤S3,当所述差分值在所述曲线图中出现跃升并回落形成峰值时,记录所述峰值顶点后的时间点,判定所述峰值顶点后的时间点为初凝时间。本申请提供了一种可行的检测石膏胶凝材料初凝时间的方法,该方法为非接触式检测方法,劳动强度低,误差小,准确性高,可用于自动化判定,适应规模化生产。(The invention provides a method for detecting the setting and hardening time of a gypsum cementing material, which comprises the following steps: step S1, continuously detecting the surface whiteness value data of the gypsum cementing material when setting and hardening, and recording and forming a surface whiteness value data sequence; step S2, calculating the difference value of the sequence according to the recorded data sequence of the surface whiteness value, and drawing a curve chart by the difference value; and step S3, when the differential value jumps and falls back to form a peak value in the graph, recording the time point after the peak value, and judging the time point after the peak value is the initial setting time. The application provides a feasible method for detecting the initial setting time of the gypsum cementing material, which is a non-contact detection method, has low labor intensity, small error and high accuracy, can be used for automatic judgment and is suitable for large-scale production.)

1. The method for detecting the setting and hardening time of the gypsum cementing material is characterized by comprising the following steps:

step S1, continuously detecting the surface whiteness value data of the gypsum cementing material when setting and hardening, and recording and forming a surface whiteness value data sequence;

step S2, calculating the difference value of the sequence according to the recorded data sequence of the surface whiteness value, and drawing a curve chart by the difference value;

and step S3, when the differential value jumps and falls back to form a peak value in the graph, recording the time point after the peak value, and judging the time point after the peak value is the initial setting time.

2. The method for detecting the setting and hardening time of gypsum cement as claimed in claim 1, wherein said step S1, continuously detecting the surface whiteness value data of the gypsum cement during setting and hardening, recording and forming the surface whiteness value data sequence, specifically comprising: step S11, mixing the gypsum cementing material with water, uniformly stirring and pouring into a mold;

step S12, continuously detecting the surface whiteness value data of the gypsum cementing material when setting and hardening at the same time interval;

step S13, recording and forming a time-based surface whiteness value data sequence.

3. The method for detecting the setting and hardening time of gypsum cement as claimed in claim 1 or 2, wherein said step S2 is performed by calculating the difference value of the recorded data sequence of surface whiteness value, and plotting the curve with said difference value, specifically comprising: a step S21 of calculating a difference value between a subsequent data and a previous data of any two adjacent data in the surface whiteness value data sequence recorded in the step S1 to obtain a difference value of the surface whiteness value data sequence;

and step S22, drawing a coordinate system by taking time as a horizontal axis and a surface whiteness change value as a vertical axis, and recording the difference value in the coordinate system to form a curve graph of the surface whiteness change rate when the gypsum cementing material is set and hardened.

4. The method for detecting the setting and hardening time of gypsum cement as claimed in claim 3, wherein said step S3, when said differential value appears to jump and fall back in said graph to form a peak, records the time point after the peak, and determines the time point after the peak as the initial setting time, specifically comprises:

step S31, according to the graph, the difference value is analyzed for the jump peak value, and the jump peak value is judged;

step S32, determining the first time point after the peak is determined as T according to the jump peak value_CDetermining said T_CThe initial setting time is indicated.

5. The method for detecting the setting and hardening time of gypsum cement as claimed in claim 4, wherein said step S31 is implemented by analyzing the jump peak of said difference values according to said graph, and determining the jump peak, specifically comprising: step S311, performing a setting and hardening whiteness value variation detection experiment on the gypsum cementing materials of the same type, the same batch or the same source to obtain a threshold value of the gypsum cementing materials of the type, the batch or the same source;

step S312, determining a jump peak of the difference value according to the threshold value.

6. The method for detecting the setting and hardening time of gypsum cement as claimed in claim 5, wherein said step S312 of determining the jump peak of said differential value according to said threshold value specifically comprises:

step S3121, when the differential value of the first point is greater than the threshold value and the differential value of the second point is greater than the differential value of the first point, continuing to measure the data of the whiteness value, and calculating the differential value according to the step S21;

and S3122, if the difference value measured and calculated continuously is smaller than the threshold value for the first time at the x-th point, determining that the jump peak value is between the first point and the x-th point, and determining that the time point of the x-th point is the initial setting time.

7. The method for detecting the setting and hardening time of gypsum cement according to claim 5, wherein said threshold value is less than or equal to the vertex value of said jump peak.

8. The method for detecting the setting and hardening time of gypsum cement according to claim 2, wherein the intervals have the same time length of 0.1 second, 0.2 second, 0.5 second, 1 second, 2 seconds or 5 seconds.

9. The method for detecting the setting and hardening time of the gypsum cementing material according to claim 1, wherein the gypsum cementing material is any one of phosphogypsum, desulfurized gypsum, titanium gypsum and natural building gypsum.

10. The method for detecting the setting and hardening time of the gypsum cementing material according to claim 1, wherein the data of the surface whiteness value is an average value of the surface whiteness values of the gypsum cementing material in the same area of an aperture of a whiteness meter at the same time point.

Technical Field

The invention relates to the technical field of gypsum setting detection, in particular to a method for detecting the setting and hardening time of a gypsum cementing material.

Background

Gypsum cementitious materials are a versatile air-setting material made from dihydrate gypsum (CaSO 4.2H 2O) that is dehydrated at different temperatures and pressures. The gypsum masonry product using industrial by-product gypsum as main raw material is a comprehensive utilization mode of main gypsum. Gypsum masonry products are currently produced primarily in the cast mode. The setting and hardening time of the gypsum cementing material is relatively fast, but the physical properties of industrial by-product gypsum are greatly different due to different sources, types, calcining processes, aging processes and the like, and the setting and hardening time of materials in different production places and batches is greatly changed. In the production process of the gypsum masonry product, when gypsum is set and hardened to a certain degree, a fixed core for product forming in a mould needs to be drawn out, namely the initial setting time of the gypsum masonry product, and the determination of the initial setting time has great influence on the production of the gypsum masonry product.

At present, the detection method of the setting and hardening time of the gypsum cementing material mainly comprises a Vicat penetration method and an empirical method. The Vicat penetration method is from the detection method of gypsum setting time in national standard GB/T9776 building gypsum, and the method comprises the steps of filling mixed gypsum slurry into a cone mould with standard size, carrying out inserting and smashing and light vibration for a plurality of times, scraping redundant clean slurry, quickly placing the flat slurry on a fixed position below a test cone, lowering a steel needle to the surface of the clean slurry, tightening a screw for 1-2 seconds, suddenly releasing, and allowing the steel needle to be vertically and freely inserted into the gypsum slurry, wherein the operation is repeated every 30 seconds. The time that the steel needle is inserted into the gypsum slurry and cannot touch the glass bottom plate for the first time is the initial setting time of the gypsum slurry, namely the initial setting time. The method is a standard unified test method, has accurate data, but has the defects of more complicated operation, high labor intensity and low detection efficiency when being used for large-scale gypsum product production. The rule of thumb is that a person presses the surface of the gypsum slurry with a finger, and the pressing person judges whether the gypsum cementing material begins to set or not by the experience according to the force applied to the surface of the gypsum slurry by the pressing person. The method has higher requirements on the experience of personnel, and different personnel have different experiences, so that the setting time judgment of the same gypsum slurry has larger difference, namely the setting time judgment is greatly influenced by human factors. In addition, there is also a method of determining the setting of gypsum by using the temperature rise during the setting of gypsum, which can determine the setting of gypsum, but the result is generally in the latter stage of setting and hardening of gypsum, and the initial setting of the gypsum-containing material cannot be determined, that is, the initial setting time cannot be determined.

Therefore, a detection method which is simple and convenient to operate, suitable for large-scale production and capable of accurately judging the setting and hardening time of the gypsum cementing material is urgently needed to be developed.

Disclosure of Invention

Aiming at the technical problems of the gypsum cementing material setting and hardening time detection method in the prior art, the invention provides the gypsum cementing material setting and hardening time detection method which is accurate in judgment, simple in operation and suitable for large-scale production.

The technical scheme adopted by the invention is as follows:

the method for detecting the setting and hardening time of the gypsum cementing material comprises the following steps:

step S1, continuously detecting the surface whiteness value data of the gypsum cementing material when setting and hardening, and recording and forming a surface whiteness value data sequence;

step S2, calculating the difference value of the sequence according to the recorded data sequence of the surface whiteness value, and drawing a curve chart by the difference value;

and step S3, when the differential value jumps and falls back to form a peak value in the graph, recording the time point after the peak value, and judging the time point after the peak value is the initial setting time.

In an embodiment of the present application, the step S1, continuously detecting the surface whiteness value data when the gypsum cement is set and hardened, and recording and forming a surface whiteness value data sequence, specifically includes:

step S11, mixing the gypsum cementing material with water, uniformly stirring and pouring into a mold;

step S12, continuously detecting the surface whiteness value data of the gypsum cementing material when setting and hardening at the same time interval;

step S13, recording and forming a time-based surface whiteness value data sequence.

In an embodiment of the application, the step S2, calculating a difference value of a sequence according to the recorded data sequence of the surface whiteness value, and drawing a graph with the difference value specifically includes:

a step S21 of calculating a difference value between a subsequent data and a previous data of any two adjacent data in the surface whiteness value data sequence recorded in the step S1 to obtain a difference value of the surface whiteness value data sequence;

and step S22, drawing a coordinate system by taking time as a horizontal axis and a surface whiteness change value as a vertical axis, and recording the difference value in the coordinate system to form a curve graph of the surface whiteness change rate when the gypsum cementing material is set and hardened.

In an embodiment of the application, in step S3, when the differential value jumps and falls back to form a peak in the graph, recording a time point after the peak is peaked, and determining that the time point after the peak is an initial setting time includes:

step S31, according to the graph, the difference value is analyzed for the jump peak value, and the jump peak value is judged;

step S32, determining the first time point after the peak is determined as T according to the jump peak value_CDetermining said T_CThe initial setting time is indicated.

In an embodiment of the application, the step S31, performing a jump peak analysis on the difference value according to the graph, and determining a jump peak specifically includes:

step S311, performing a setting and hardening whiteness value variation detection experiment on the gypsum cementing materials of the same type, the same batch or the same source to obtain a threshold value of the gypsum cementing materials of the type, the batch or the same source;

step S312, determining a jump peak of the difference value according to the threshold value.

In an embodiment of the application, the step S312, determining a jump peak of the difference value according to the threshold value specifically includes:

step S3121, when the differential value of the first point is greater than the threshold value and the differential value of the second point is greater than the differential value of the first point, continuing to measure the data of the whiteness value, and calculating the differential value according to the step S21;

and S3122, if the difference value measured and calculated continuously is smaller than the threshold value for the first time at the x-th point, determining that the jump peak value is between the first point and the x-th point, and determining that the time point of the x-th point is the initial setting time.

In one embodiment of the present application, the threshold value is less than or equal to a vertex value of the jump peak.

In one embodiment of the present application, the intervals are of the same duration 0.1 second, 0.2 second, 0.5 second, 1 second, 2 seconds, or 5 seconds apart.

In one embodiment of the present application, the gypsum-binding material is any one of phosphogypsum, desulfurized gypsum, titanium gypsum and natural building gypsum.

In one embodiment of the present application, the surface whiteness value data is an average value of the surface whiteness values of the gypsum cement in the same area of the whiteness meter aperture at the same time point.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention provides an accurate and feasible method for detecting the initial setting time of a gypsum cementing material.

2. The method for detecting the setting and hardening time of the gypsum cementing material is a detection method based on the change of the whiteness value of the surface of the gypsum cementing material, and can accurately detect the initial setting time of the gypsum cementing material through the change of the whiteness value of the surface so as to timely extract a fixed core in a mold and ensure the quality of a gypsum masonry product; compared with the result of a Vicat instrument experimental method, the detection result of the method has the advantages that the difference is within the range of +/-30 seconds, and the accuracy is higher; the method is suitable for automatic determination of initial setting time of gypsum cementing material products such as building blocks, wallboards and the like in large-scale production, has low labor intensity and small error, can be used for automatic determination, and has high accuracy. And the method is a non-contact detection method, so that the damage to the gypsum cementing material product can be effectively reduced, and the quality of the product is further ensured.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic flow chart of a method for detecting setting and hardening time of a gypsum cementing material provided by the invention.

Figure 2 is a graph of the surface whiteness rate of the phosphogypsum in one example when setting and hardening.

Figure 3 is a graph of the surface whiteness change rate of phosphogypsum in another example when setting and hardening.

FIG. 4 is a graph showing the surface whiteness change rate at the time of setting and hardening of desulfurized gypsum in one example.

FIG. 5 is a graph showing a surface whiteness change rate when natural gypsum is set to harden according to an example.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a schematic flow chart of a method for detecting setting and hardening time of a gypsum cementing material according to an embodiment of the present invention is provided. The method for detecting the setting and hardening time of the gypsum cementing material comprises the following steps:

step S1, data acquisition: continuously detecting surface whiteness value data of the gypsum cementing material during setting and hardening, and recording to form a surface whiteness value data sequence;

step S2, data processing: calculating the difference value of the sequence according to the recorded data sequence of the surface whiteness value, and drawing a curve graph by using the difference value;

step S3, data analysis and determination: when the differential value jumps and falls back to form a peak value in the graph, recording the time point after the peak value, and judging the time point after the peak value is the initial setting time.

The method for detecting the setting and hardening time of the gypsum cementing material is a detection method based on the change condition of the surface whiteness value when the gypsum cementing material is set and hardened, and the method adopts equipment such as a whiteness meter and the like to continuously detect and compare the surface whiteness value data, and can judge the initial setting of the gypsum cementing material when the surface whiteness value has a jump change. The method belongs to a material characteristic detection and judgment method, does not contact gypsum cementing materials in the detection process, has accurate detection result and small error, can be suitable for large-scale automatic detection and judgment, and has low labor intensity.

Optionally, in step S1, the surface whiteness value data of the gypsum cement at the time of setting and hardening are continuously detected, and a sequence of the surface whiteness value data is recorded, specifically including:

step S11, mixing the gypsum cementing material with water, uniformly stirring and pouring into a mold;

step S12, continuously detecting the data of the surface whiteness value of the gypsum cementing material in the mould when the gypsum cementing material is set and hardened at the same time interval;

in step S13, the detected data is recorded to form a time-based surface whiteness value data series.

The surface whiteness values of the gypsum cementing material during setting and hardening are continuously detected at the same time interval, and a surface whiteness value data sequence based on time is formed, so that the change situation of the surface whiteness values of the gypsum cementing material during setting and hardening can be more accurately reflected, and a data basis is provided for accurately judging the initial setting time.

Optionally, in step S2, calculating a difference value of the sequence according to the recorded data sequence of the surface whiteness value data, and drawing a graph by using the difference value, specifically including:

step S21 of calculating a difference between the next data and the previous data of any two adjacent data in the data sequence of surface whiteness value recorded in the step S1 to obtain a difference value of the data sequence of surface whiteness value;

and step S22, drawing a coordinate system with time as horizontal axis and surface whiteness variation as vertical axis, recording the difference value in the coordinate system, and forming a graph of surface whiteness variation rate when the gypsum cementing material is set and hardened.

And subtracting the former data from the latter data in the surface whiteness value data sequence to obtain a group of time-based difference value sequences which are the difference values of the surface whiteness value data sequence, namely the surface whiteness change rate. The change trend of the surface whiteness value data can be amplified through the differential value, the change condition of the surface whiteness value can be reflected more accurately, and the initial setting time can be judged more accurately.

Optionally, in step S3, when the difference value jumps and falls back in the graph to form a peak, recording a time point after the peak, and determining that the time point after the peak is the initial setting time, specifically, the method includes:

step S31, analyzing the difference value for a jump peak according to the graph, and determining the jump peak;

step S32, determining the peak value from the jump peak value, and setting the first time point as T_CDetermining the T_CAt the time of initial settingAnd (3) removing the solvent.

Optionally, in step S31, performing a jump peak analysis on the difference value according to the graph to determine a jump peak, specifically including:

step S311, performing a setting and hardening whiteness value variation detection experiment on the gypsum cementing materials of the same type, batch or source to obtain a threshold value of the gypsum cementing materials of the type, batch or source;

in step S312, the jump peak of the difference value is determined according to the threshold value.

Because gypsum cementing materials of different types, different batches, different sources, different calcining processes or different aging processes have larger difference in physical properties and different setting and hardening times, a detection experiment for detecting the change of the setting and hardening whiteness value of the gypsum cementing materials of different types, batches and sources is needed to determine the change condition of the surface whiteness value during initial setting, namely the size range of the time difference value when the jump peak occurs. And determining a lower limit value, namely a threshold value, according to the size range of the score of the time difference of occurrence of the jump peak. When the differential value is greater than the threshold value, a jump in the differential value is indicated, i.e., the gypsum cement is near incipient setting. The threshold value is set, so that the accuracy of initial setting time judgment can be increased, the initial setting time is prevented from being missed, and the production and processing quality of the gypsum masonry product is ensured.

Optionally, in step S312, determining a jump peak of the difference value according to the threshold value specifically includes:

step S3121, when the differential value of the first point is greater than the threshold value and the differential value of the second point is greater than the first point differential value, continuing to measure the surface whiteness value data, and calculating the differential value according to the step S21;

and step S3122, if the difference value measured and calculated continuously is smaller than the threshold value for the first time at the x-th point, judging that the jump peak value is between the first point and the x-th point, and determining that the time point of the x-th point is the initial setting time.

And judging the jump peak value of the difference value (namely the change of the surface whiteness value) through a threshold value, and judging the time of the x-th point which is smaller than the threshold value for the first time after the reversion as the initial setting time, thereby ensuring the accuracy of the initial setting time judgment.

Optionally, the threshold value is less than or equal to a vertex value of the jump peak. Specifically, the threshold value may be determined by detecting the change of the surface whiteness value during the setting and hardening process of the gypsum cement of the type, the batch, or the source for a plurality of times, analyzing and processing to obtain a plurality of peak values of differential value jump peaks, and determining the threshold value of the gypsum cement by using 80% of the average value of the plurality of peak values. The operation of judging the occurrence of the jump peak value according to the threshold value is accurate and reliable.

In the step S12, the data of the surface whiteness value of the gypsum cement at the time of setting and hardening is continuously detected at the same time interval. The time duration of the interval can be 1-10 seconds. Specifically, the intervals may be 0.1 second, 0.2 second, 0.5 second, 1 second, 2 seconds, 5 seconds, 10 seconds, or the like. That is, surface whiteness value data of the gypsum cement is detected and recorded every 0.1 second, 0.2 second, 0.5 second, 1 second, 2 seconds, 5 seconds, or 10 seconds. Therefore, in order to make the initial setting time determination more accurate, the time interval between two detections can be appropriately shortened.

The gypsum cementing material in the embodiment can be natural building gypsum, phosphogypsum, desulfurized gypsum, titanium gypsum and the like.

Referring to fig. 2 to 5, there are graphs of surface whiteness values of a portion of gypsum-binding material after differential processing, i.e., surface whiteness rate graphs, when the gypsum-binding material is set and hardened. As can be seen from FIGS. 2 to 5, the whiteness value data of the gypsum cement material at the initial setting time is obviously increased, so that the detection method of the embodiment is used for non-contact detection, and the initial setting time of the gypsum cement material is really determined, and the determination accuracy is high.

Optionally, fig. 2 is a surface whiteness change rate graph formed by mixing phosphogypsum with water, pouring the mixture into a mold, and detecting, recording and processing the surface whiteness value of the mixture during setting and hardening. As can be seen from FIG. 2, the threshold value of the phosphogypsum is 2.5, and the initial setting time is determined to be 3.3 min.

FIG. 3 is a surface whiteness change rate curve diagram formed by mixing another kind of phosphogypsum with water, pouring the mixture into a mold, and detecting, recording and processing the surface whiteness value when the mixture is coagulated and hardened. As can be seen from FIG. 3, the threshold value of the phosphogypsum is 2.5, and the initial setting time is determined to be 3.8 min.

FIG. 4 is a surface whiteness change rate graph of desulfurized gypsum mixed with water, poured into a mold, and subjected to detection, recording and treatment of surface whiteness values during setting and hardening. As can be seen from FIG. 4, the threshold value of the desulfurized gypsum was 3.0, and the initial setting time was determined to be 6.9 min.

FIG. 5 is a surface whiteness change rate graph of natural building gypsum mixed with water, poured into a mold, and subjected to detection, recording and treatment of surface whiteness values during setting and hardening. As can be seen from FIG. 5, the threshold value of the natural building gypsum was 2.5, and the initial setting time was determined to be 5.3 min.

As can be seen from FIGS. 2 to 5, there are some differences in threshold values and initial setting times for different types of gypsum binders.

In order to ensure that the detected surface whiteness value is accurate and reliable, the surface whiteness value at each time point is the average value of the surface whiteness values of the gypsum cementing materials in the same area of the aperture of the whiteness meter. The surface whiteness values of a plurality of point positions on the surface of the gypsum cementing material can be collected, the average value of the surface whiteness values of the plurality of point positions is used as the surface whiteness value of the time point, and the accuracy is higher.

In summary, the method for detecting the setting and hardening time of the gypsum cementing material is a detection method based on the change of the whiteness value of the surface of the gypsum cementing material, and the method can accurately detect and judge the initial setting time of the gypsum cementing material through the change of the whiteness value of the surface so as to timely extract a fixed core in a mold and ensure the quality of a gypsum masonry product; compared with the result of a Vicat instrument experimental method, the detection result of the method has the advantages that the difference is within the range of +/-30 seconds, and the accuracy is higher; the accuracy of the method for judging the initial setting time can be improved by properly shortening the interval time between two detection of the surface whiteness values; the method is suitable for judging the initial setting time of gypsum cementing material products such as building blocks, wallboards and the like in large-scale production, has low labor intensity and small error, can be used for automatic judgment, and has high accuracy. And the method is a non-contact detection method, so that the damage to the gypsum cementing material product can be effectively reduced, and the quality of the product is further ensured.

It should be noted that, the sequence of steps in the method for detecting setting and hardening time of gypsum cement material in this embodiment is not fixed, and may be performed sequentially, or the sequence may be changed according to specific situations; a certain step may be performed separately in a certain period, or multiple steps may be performed simultaneously, or multiple steps may be performed with partial overlapping of a period.