JP2016180748A - Selection method of blast furnace slag, and manufacturing method of blast furnace cement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a selection method of a blast furnace slag and a manufacturing method of a blast furnace cement that can accurately predict an activity index of cement and can select a blast furnace slag as a cement material having a high activity index.SOLUTION: The selection method of a blast furnace slag includes an indicator calculation process and a selection process. In the indicator calculation process, a basicity Bu (seven days) of the blast furnace slag as an indicator of the activity index of the cement of mortar material age of seven days is calculated using the following equation (1) Bu(seven days)=(CaO+a×MgO+b×AlO)/SiO-c×TiO-d×MnO...(1). In the equation (1), a is 0.05-0.65, b is 0.05-0.95, c is 0.15-2.00, and d is 0.05-0.95. In the selection process, a blast furnace slag is selected on the basis on the basicity Bu (seven days) as the indicator.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blast furnace slag sorting method that predicts an activity index more accurately than a conventional prediction index and sorts blast furnace slag, and a blast furnace cement manufacturing method that mixes the sorted blast furnace slag and cement.

Blast furnace granulated slag produced from steelworks is approximately 20 million tons in 2013, of which approximately 90% is used as cement raw material. Among them, the quality of slag used for blast furnace cement has a great influence on the quality of the blast furnace cement, and is calculated by the following formula (S) defined in JIS (JIS A 6206 “Blast furnace slag fine powder for concrete”). Basicity ((CaO + MgO + Al ₂ O ₃ ) / SiO ₂ ) is treated as a quality control index value for blast furnace slag. The basicity calculated by the following formula (S) may be referred to as JIS basicity ( _BJIS ) in this specification.
JIS basicity (B _JIS ) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ (S)

The activity index of cement containing blast furnace slag specified in JIS (JIS A 6206 “Blast furnace slag fine powder for concrete”) is 1: 1 (normal Portland cement: blast furnace). It is represented by the ratio (mortar material age 7 days and mortar material age 28 days) between the mortar compressive strength of the cement produced so that the fine powder of slag = 1: 1) and the mortar compressive strength of ordinary Portland cement alone. It is considered that the higher the activity index of cement using blast furnace slag as a raw material, the better the quality of blast furnace slag. In general, the basicity of the blast furnace slag described above is used as an index of the activity index of the blast furnace cement, and the activity index tends to increase as the basicity increases.
However, even when the activity index of blast furnace cement is predicted with the conventional basicity, there are many variations compared to the actual measurement values. For this reason, at the actual manufacturing site, the basicity of blast furnace slag is high, so it is judged that the activity index is high, and no action is taken during production to ensure quality, and the quality of the manufactured blast furnace cement is the target. You may not reach the level.

On the other hand, in the past examination, as shown in the formula (A), the formula (A) for deriving the index (Bm) of the activity index of the blast furnace cement by adding the TiO ₂ amount and the MnO amount to the basicity of JIS. ) Has been proposed (Patent Document 1). Patent Document 1 proposes a method for predicting an activity index of cement using blast furnace slag based on an index (Bm) calculated by Expression (A). In addition, formulas (B) to (F) for deriving various basicities (B _B ) to (B _F ) have already been reported (Non-Patent Documents 1 to 3).

Index (Bm) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ −0.13 × TiO ₂ —MnO (A)

Basicity (B _B ) = CaO + (2/3) × MgO—SiO ₂ —Al ₂ O ₃ (B)

Basicity (B _C ) = (CaO + 0.7 × MgO) / (0.94 × SiO ₂ + 0.18 × Al ₂ O ₃ ) (C)

Basicity (B _D ) = (CaO + Al ₂ O ₃ + MgO + Na ₂ O + S) / (SiO ₂ + TiO ₂ ) (D)

Basicity (B _E ) = (CaO + MgO + (1/3) × Al ₂ O ₃ ) / (SiO ₂ + (2/3) × Al ₂ O ₃ ) (E)

Basicity (B _F ) = (Kc × CaO + Ka × Al ₂ O ₃ + Km × MgO + Kn × Na ₂ O + Ksu × S) / (SiO ₂ + Kt × TiO ₂ ) (F)
However, in the formula (F), when the material is 7 days old, Kc is 1.42, Ka is 1.29, Km is 1.75, Kt is 4.99, Kn is 3.33, and Ksu is 2.69. When the material is 28 days old, Kc is 0.24, Ka is 0.42, Km is 0.23, Kt is 2.63, Kn is 0.99, and Ksu is 0.45.

JP 2008-247715 A

Shinya Iwamoto, Basicity of Slag, Journal of the Japan Welding Society, pp.8-18, Vol.50 (1981) Toshikichi Yamauchi, Renichi Kondo, Cement Slag Discrimination Method, Annual Report of Cement Technology, Vol.7, pp.67-75 (1953) Maeda, Y., Naganuma, H., Hashimoto, T., Effect of chemical composition of granulated blast furnace slag on strength of blast furnace cement, Papers on cement and concrete, Vol.44, pp.180-185 (1990)

However, from the index (Bm) calculated by the equation (A) of Patent Document 1 and the basicities (B _B ) to (B _F ) calculated by the equations (B) to (F) of Non-Patent Documents 1 to 3. In addition, an index that predicts the activity index with higher accuracy is desired by the industry.
Therefore, the present invention can accurately predict the activity index of cement using blast furnace slag, and derives an equation for deriving basicity as an index for selecting blast furnace slag as a cement raw material having an excellent activity index. The object of the present invention is to provide a blast furnace slag sorting method and a blast furnace cement manufacturing method based on the proposed basicity.

  Further, mixed cement is required to further improve strength development and to effectively use a low activity mixed material to cope with future increase in the amount of mixed material used. Therefore, the present invention provides a blast furnace cement that is more excellent in strength development while using the blast furnace slag selected by the index, and effectively uses the low activity slag selected by the index. Another object is to provide a blast furnace cement with good properties.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that each chemistry shown in basicity ((CaO + MgO + Al ₂ O ₃ ) / SiO ₂ ) defined in JIS A6206, together with TiO ₂ and MnO of blast furnace slag. By reviewing the effect of the components on the activity index of cement, it is possible to derive a formula that calculates the basicity that serves as an index for selecting blast furnace slag, and accurately predicts the activity index of cement using blast furnace slag. It was found that blast furnace slag can be selected as a cement raw material having an excellent activity index, and the present invention has been completed.

In the present invention, the basicity Bu (7 days) of blast furnace slag, which serves as an index of the activity index of a 7-day-old cement, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
And a sorting method for sorting blast furnace slag based on the basicity Bu (7 days) serving as an index.
The present invention relates to a blast furnace slag sorting method in which the basicity Bu (7 days) calculated by the formula (1) is any value from 0 to 1.70.
In the present invention, the sorting step sorts the blast furnace slag whose basicity of the blast furnace slag is equal to or higher than the basicity Bu (7 days) calculated by the formula (1) as a high activity blast furnace slag, The present invention relates to a method for sorting blast furnace slag, including a step of sorting blast furnace slag that is less than the value of basicity Bu (7 days) calculated by equation (1) as low activity blast furnace slag.

In the present invention, the basicity Bu (28 days) of blast furnace slag, which serves as an index of the activity index of cement with a mortar age of 28 days, is expressed by the following formula (2).
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95.)
And a sorting process for sorting blast furnace slag based on the basicity Bu (28 days) serving as an index.
The present invention relates to a method for sorting blast furnace slag, wherein the basicity Bu (28 days) calculated by the formula (2) is any value of −0.20 to 1.70.
In the present invention, the sorting step sorts blast furnace slag whose basicity of the blast furnace slag is equal to or higher than the basicity Bu (28 days) calculated by the formula (2) as a high activity blast furnace slag, The present invention relates to a method for sorting blast furnace slag, including a step of sorting blast furnace slag that is less than the value of basicity Bu (28 days) calculated by Expression (2) as low activity blast furnace slag.

In the present invention, the basicity Bu (7 days) of the blast furnace slag, which is an index of the activity index of the blast furnace slag 7 days old, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
An index calculation process calculated by the above, a selection process for selecting blast furnace slag based on the basicity Bu (7 days) as an index, and a manufacturing process for manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement The basicity Bu (7 days) of the blast furnace slag calculated by the formula (1) is any value from 0 to 1.70, and in the sorting step, the basicity of the blast furnace slag is the base Selecting a blast furnace slag having a degree of Bu (7 days) or more as a high activity blast furnace slag and selecting a blast furnace slag having a value less than the basicity Bu (7 days) as a low activity blast furnace slag. The present invention relates to a method for producing blast furnace cement.

In the present invention, the basicity Bu (28 days) of blast furnace slag, which serves as an index of the activity index of cement with a mortar age of 28 days, is expressed by the following formula (2).
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)
An index calculation process calculated by the above, a selection process of selecting blast furnace slag based on the basicity Bu (28 days) as an index, and a manufacturing process of manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement The basicity Bu (28 days) of the blast furnace slag calculated by the formula (2) is any value of −0.20 to 1.70, and in the sorting step, the basicity of the blast furnace slag is The blast furnace slag having a value equal to or higher than the basicity Bu (28 days) is selected as a high activity blast furnace slag, and the blast furnace slag having a value less than the basicity Bu (28 days) is selected as a low activity blast furnace slag. The present invention relates to a method for producing blast furnace cement, including a process.

The present invention is based on an index calculation step for calculating basicity Bu (7 days) or basicity Bu (28 days) of blast furnace slag, and basicity Bu (7 days) or basicity Bu (28 days). A method for producing blast furnace cement, comprising: a sorting step of sorting blast furnace slag into low activity slag and high activity slag; and a mixing step of mixing the low activity slag, the high activity slag and cement,
The index calculating step calculates the basicity Bu (7 days) of blast furnace slag, which is an index of the activity index of 7 days of mortar material, by the formula (1), and the activity index of 28 days of mortar material age Including at least one of the steps of calculating the basicity Bu (28 days) of blast furnace slag as an index of
The step of selecting the low activity slag and the high activity slag according to the threshold of basicity Bu (7 days) set in the range of 0 to 1.70; and in the range of -0.2 to 1.70. Including at least one of a step of selecting low-activity slag and high-activity slag according to a threshold of the set basicity Bu (28 days),
The mixing step further includes a step of blending the low activity slag and the high activity slag so that the basicity Bu (7 days) or the basicity Bu (28 days) is equal to or greater than the threshold value. The present invention relates to a method for producing a blast furnace cement.

The present invention is based on an index calculation step for calculating basicity Bu (7 days) or basicity Bu (28 days) of blast furnace slag, and basicity Bu (7 days) or basicity Bu (28 days). A method for producing a blast furnace cement, comprising a selection step of selecting low activity slag from blast furnace slag, a mixing step of mixing the low activity slag and cement, and a strength complementation step,
The index calculating step calculates the basicity Bu (7 days) of blast furnace slag, which is an index of the activity index of 7 days of mortar material, by the formula (1), and the activity index of 28 days of mortar material age Including at least one of the steps of calculating the basicity Bu (28 days) of blast furnace slag as an index of
The basicity Bu (7 days) of the low activity slag in the calculation step is any value of 0 to 1.70 or Bu (28 days) is -0.20 to 1.70,
The step of selecting low activity slag by the threshold of basicity Bu (7 days) set in the range of 0 to 1.70; and the basicity Bu set in the range of -0.2 to 1.70. The present invention relates to a method for producing a blast furnace cement, comprising at least one of a step of selecting low-activity slag according to a threshold of (28 days).

The present invention provides the method for producing a blast furnace cement, wherein the strength supplementing step includes a step of adjusting the fineness of the blast furnace slag, a step of adjusting the fineness of the Portland cement, and a step of adjusting the fineness of the blast furnace cement. The present invention relates to a method for producing blast furnace cement, comprising at least one step selected from the group consisting of:
The present invention relates to the method for producing blast furnace cement, wherein the strength supplementing step includes a step of adjusting an addition amount of an inorganic substance containing chlorine.
The present invention relates to a method for producing a blast furnace cement, wherein the strength supplementing step includes a step of adjusting an addition amount of gypsum in the method for producing a blast furnace cement.
The present invention relates to the method for producing blast furnace cement, wherein the strength supplementing step includes a step of adjusting an amount of limestone added.

  According to the blast furnace slag sorting method of the present invention, even if the quality of the blast furnace slag varies, the mortar activity index can be accurately predicted, and a good blast furnace slag usable as a cement raw material having an excellent activity index is selected. A method can be provided. Further, according to the method for producing blast furnace cement of the present invention, it is possible to provide a production method for producing good quality blast furnace cement by selecting good blast furnace slag and using the selected blast furnace slag as a cement raw material. it can.

The relationship between the basicity Bu (7 days) calculated by the formula (1) of the present invention and the activity index of the mortar age 7 days, and the basicity Bu (28 days calculated by the formula (2) of the present invention. ) And the activity index relationship of mortar age 28 days. Graph showing JIS basicity is calculated as (B _JIS), the relationship between the activity index of the active index and mortar ages 28 days the mortar ages 7 days by formula (S). The graph which shows the relationship between the parameter | index (Bm) calculated by the conventional formula (A), the activity index of the mortar material age 7 days, and the activity index of the mortar material age 28 days. Basicity calculated by conventional formulas (B) and (B _B), a graph showing the relationship between the activity index of the active index and mortar ages 28 days the mortar ages 7 days. The graph which shows the relationship between the basicity (B _C ) calculated by the conventional formula (C), the activity index of mortar material age 7 days, and the activity index of mortar material age 28 days. Basicity calculated by conventional formulas (D) and (B _D), a graph showing the relationship between the activity index of the active index and mortar ages 28 days the mortar ages 7 days. Basicity calculated by conventional formulas (E) and (B _E), a graph showing the relationship between the activity index of the active index and mortar ages 28 days the mortar ages 7 days. The graph which shows the relationship between the basicity (B _F7 ) of the mortar material age 7 days calculated by the conventional formula (F) and the activity index of the mortar material age 7 days. The graph which shows the relationship between the basicity (B _F28 ) of the mortar material age 28 days calculated by the conventional formula (F), and the activity index of the mortar material age 28 days. The graph which shows the relationship between the brane specific surface area of the blast furnace cement produced by separation crushing, and the strength ratio with respect to a reference | standard. Graph showing the SO ₃ content of from gypsum slag flour produced in separate grinding, the relationship between the intensity ratio with respect to the reference of the blast-furnace slag cement prepared using the slag powder. The graph which shows the relationship between the intensity | strength ratio with respect to the reference | standard of the blast furnace cement produced using the amount of limestone in the slag powder produced by isolation | separation grinding | pulverization, and this slag powder. The graph which shows the relationship between the brane specific surface area of the blast furnace cement produced by mixed grinding, and the strength ratio with respect to a reference | standard. Graph showing the SO ₃ content of from gypsum blast furnace cement produced, the relation between the intensity ratio with respect to the reference in mixing and grinding. The graph which shows the relationship between the amount of limestone in the blast furnace cement produced by mixing grinding | pulverization, and the strength ratio with respect to a reference | standard.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

<Blast furnace slag sorting method>
The blast furnace slag sorting method of the present embodiment is based on the chemical composition of the blast furnace slag, and the basicity Bu (7 days) of the blast furnace slag, which serves as an index of the activity index of the cement with a mortar age of 7 days, is expressed by the formula (1). An index calculation process to calculate, and a selection process to select blast furnace slag based on the basicity Bu (7 days) serving as the index.
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)

The chemical composition of blast furnace slag affects the strength development of cement using blast furnace slag as a raw material. As an index of strength development of cement using blast furnace slag as a raw material, for example, the activity index of mortar is shown in JIS A 6206 “Blast furnace slag fine powder for concrete”. The activity index is a numerical value representing the ratio of the compressive strength of the test mortar to the compressive strength of the standard mortar as a percentage. Standard mortar is usually mortar using normal Portland cement. The test mortar is a mortar using blast furnace cement in which blast furnace slag (blast furnace granulated slag (fine powder)) and ordinary Portland cement are blended at a ratio of 1: 1. A compressive strength S1 of the test mortar using this blast furnace cement (N / mm ^2), the compressive strength of standard mortar using ordinary portland cement S (N / mm ²⁾ as shown in the following formula (3), the active A degree index (%) can be calculated.
Activity index (%) = S1 (compressive strength of test mortar) / S (compressive strength of standard mortar) × 100 (3)

As an index for predicting an activity index such as strength development of cement using blast furnace slag as a raw material, JIS A 6206 "Blast furnace slag fine powder for concrete" has the following formula calculated based on chemical components of blast furnace slag The JIS basicity ( _BJIS ) shown by (S) is shown. This JIS basicity is known as a representative index of the activity index of cement using blast furnace slag as a raw material. JIS basicity _{(B JIS),} among the chemical components in the blast furnace slag can be determined CaO, MgO, from the content of SiO ₂ and _Al 2 _{O 3.}
JIS basicity (B _JIS ) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ (S)

In this specification, the content of chemical components such as CaO, MgO, SiO ₂ , Al ₂ O ₃ , TiO ₂ , and MnO in the blast furnace slag is JIS R 5202 “Chemical analysis method for Portland cement” or JIS R 5204 “Cement”. The X-ray fluorescence analysis method "can be used for measurement.

The correlation between the JIS basicity ( _BJIS ) of blast furnace slag and the activity index of cement using this blast furnace slag as a raw material varies widely. In JIS A 6202 "Blast furnace slag fine powder for concrete", the basicity is The lower limit is set to be higher than 1.60. Regarding the relationship between JIS basicity ( _BJIS ) and activity index of blast furnace slag, even if the activity index is sufficiently high, the lower limit of JIS basicity ( _BJIS ) of blast furnace slag is set higher. Therefore, blast furnace slag that is lower than the lower limit of the JIS basicity (B _JIS ) set to a high value cannot be used as a cement raw material.

Calculate the following formula (A) in consideration of the influence of the TiO ₂ content and MnO content in the blast furnace slag on the activity index in order to predict the basicity group having a strong correlation with the activity index. A blast furnace slag sorting method using the selected index (Bm) as a sorting standard has been proposed.
Index (Bm) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ −0.13 × TiO ₂ —MnO (A)

  However, when the index (Bm) calculated by the equation (A) is used as the selection criterion, there is a variation in the relationship between the activity index and the index (Bm). Therefore, an index having a strong correlation with the activity index is required. The present invention has a strong correlation with the activity index of cement, and the basicity Bu (7) calculated by the equation (1) as an index for selecting blast furnace slag as a raw material of cement having an excellent activity index. Day) or basicity Bu (28 days) calculated by formula (2) is defined, and based on this basicity Bu (7 days) or basicity Bu (28 days), the blast furnace slag is accurately Can be sorted.

  The present invention has found a chemical component of blast furnace slag that strongly affects the activity index of cement in an equation for deriving basicity used as an index for selecting blast furnace slag. The present invention can predict the basicity group of blast furnace slag having a strong correlation with the activity index of cement using blast furnace slag, and accurately selects blast furnace slag that can be used as a raw material for cement with high activity. Obtained formulas (1) and (2) were defined.

In the index calculation step of the present invention, the basicity Bu (7 days) group calculated by the following formula (1) has a strong correlation with the activity index of 7 days of mortar material age, and accurately predicts the activity index. It can be used as an indicator. In the index calculating step of the present invention, the basicity Bu (7 days) of the blast furnace slag is calculated by the following formula (1), and a blast furnace cement having an excellent activity index is calculated from the value of the basicity Bu (7 days). Blast furnace slag to obtain can be selected.
Bu (7 days) = (CaO + a × MgO + b × Al 2 O 3) / SiO 2 -c × TiO 2 -d × MnO ··· (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)

In the formula (1), CaO, Al ₂ O ₃ , MgO, SiO ₂ , TiO and MnO are the contents of each chemical component in the blast furnace slag. In the formula (1), a is 0.05 to 0.65, preferably a is 0.20 to 0.60, more preferably a is 0.35 to 0.55, and most preferably a is 0.00. 37-0.50. In formula (1), b is 0.05-0.95, preferably b is 0.10-0.70, more preferably b is 0.20-0.60, most preferably b is 0.20-0. 0.31. In formula (1), c is 0.15 to 2.00, preferably c is 0.25 to 1.00, more preferably c is 0.30 to 0.55, and most preferably c is 0.35 to 0.52. In the formula (1), d is 0.05 to 0.95, preferably d is 0.08 to 0.50, more preferably d is 0.13 to 0.35, and most preferably d is 0.15 to 0.35.

In formula (1), the coefficient a of MgO amount is 0.05 to 0.65, most preferably 0.37 to 0.50, and the coefficient b of Al ₂ O ₃ amount is 0.05 to 0.95, most preferably. Is 0.20 to 0.31, the coefficient c of TiO ₂ amount is 0.15 to 2.00, most preferably 0.35 to 0.52, and the coefficient d of MnO amount is 0.05 to 0.95, most When it is preferably 0.15 to 0.35, blast furnace slag can be selected as a raw material of cement having an excellent activity index at a mortar age of 7 days. The present invention considers the amount of TiO ₂ and MnO, which are small amounts of chemical components of blast furnace slag, and reviews the influence of the amount of MgO and Al ₂ O ₃ on the activity index of blast furnace cement. We have found a new index for accurate prediction. In the formula (1) for deriving the basicity Bu (7 days), the present invention takes into consideration the influence of the TiO ₂ content and MnO content of the blast furnace slag on the activity index of cement, and the coefficient c of TiO ₂ and MnO A new quantity coefficient d has been found. In addition, the present invention reviews the influence of the blast furnace slag MgO amount and Al ₂ O ₃ amount on the activity index of cement in Formula (1) for deriving the basicity Bu (7 days). The coefficient a of MgO amount and the coefficient b of Al ₂ O ₃ amount for predicting well were newly found. In the present invention, the basicity Bu (7 days) of the blast furnace slag having a strong correlation with the activity index of 7 days of mortar material can be calculated by the formula (1), and the basicity Bu (7 days) of this blast furnace slag is calculated. ) As an index, good blast furnace slag can be selected as a raw material for cement having an excellent activity index.

  MnO in the blast furnace slag affects the activity reduction of the blast furnace slag. When the coefficient d of the MnO amount of the blast furnace slag in the formula (1) is 0.05 to 0.95, the influence of the amount of MnO that affects the activity reduction of the blast furnace slag on the activity index of the mortar material age 7 days In consideration, it is possible to derive the basicity Bu (7 days) of the blast furnace slag that has a strong correlation with the activity index and minimizes the variation in the activity index. The coefficient d of the MnO amount of the blast furnace slag of the formula (1) is a value smaller than the coefficient of the MnO amount in the index (Bm) calculated by the conventional formula (A).

TiO ₂ in the blast furnace slag affects the activity reduction of the blast furnace slag. When the coefficient c of the TiO ₂ amount of the blast furnace slag in the formula (1) is 0.15 to 2.00, the activity index of the mortar material age 7 days of the TiO ₂ amount affecting the activity reduction of the blast furnace slag Considering the influence, it is possible to derive the basicity Bu (7 days) of the blast furnace slag which has a strong correlation with the activity index and minimizes the variation in the activity index. Effect on the activity index of the TiO ₂ content in the blast furnace slag is large, the coefficient c of the TiO ₂ amount of blast furnace slag of formula (1) is, TiO ₂ in the index (Bm) calculated by the conventional formula (A) It is a value larger than the coefficient of quantity.

MgO in the blast furnace slag contributes to improving the activity of the blast furnace slag. When the coefficient a of the MgO amount of the blast furnace slag in the formula (1) is 0.05 to 0.65, the influence of the MgO amount contributing to the activity improvement of the blast furnace slag on the activity index of the mortar material age 7 days In consideration, it is possible to derive the basicity Bu (7 days) of the blast furnace slag that has a strong correlation with the activity index and minimizes the variation in the activity index. The coefficient a of the MgO amount of the blast furnace slag of the formula (1) is an index (Bm) calculated by the coefficient of the MgO amount in the JIS basicity (B _JIS ) calculated from the conventional formula (S) or the formula (A). This is a value smaller than the coefficient of the MgO amount.

Al ₂ O ₃ in the blast furnace slag contributes to improving the activity of the blast furnace slag. When the coefficient b of the Al ₂ O ₃ amount of the blast furnace slag in the formula (1) is 0.05 to 0.95, the activity of the mortar material 7 days old with the Al ₂ O ₃ amount contributing to the activity improvement of the blast furnace slag Considering the influence on the degree index, the basicity Bu (7 days) of the blast furnace slag having a strong correlation with the degree of activity index and the smallest variation in the degree of activity index can be derived. The coefficient b of the Al ₂ O ₃ amount of the blast furnace slag of the formula (1) is the Al in the index (Bm) calculated by the JIS basicity (B _JIS ) calculated by the conventional formula (S) or the formula (A). It is a value smaller than the coefficient of ₂ O ₃ amount.

  For example, the horizontal axis represents the basicity Bu (7 days) calculated when the coefficients of the equation (1) are a = 0.43, b = 0.28, c = 0.46, d = 0.27. The difference in the activity index between the regression line and the actual measurement when the activity index on the mortar material age 7 days is taken on the vertical axis (variation of the activity index) is −6.8 to 5.6%, Bu shows a strong correlation with the activity index.

  The basicity Bu (7 days) calculated by the formula (1) is preferably 0 to 1.70. The basicity Bu (7 days) calculated by the formula (1) is more preferably 0.60 to 1.30, further preferably 0.80 to 1.30, particularly preferably 0.90 to 1.30. is there. When the basicity Bu (7 days) calculated according to the formula (1) is more preferably 0.80 to 1.30, there is a strong correlation between the activity index of cement and the basicity of blast furnace slag, and high activity As a raw material for obtaining cement having a high quality, it is possible to select a blast furnace slag having a good quality and homogeneous.

If basicity Bu calculated by the equation (1) (7 days) is 0 to _1.70, each of _{CaO / SiO 2, MgO / SiO} 2, Al 2 O 3 / SiO 2, TiO 2, MnO From the results of multiple regression analysis when the term is an independent variable and the activity index of cement is a dependent variable, the coefficient a of MgO, the coefficient b of Al ₂ O ₃ , the coefficient c of TiO ₂ , and the coefficient of MnO in formula (1) A coefficient d can be determined. The basicity Bu (7 days) calculated by the equation (1) is, for example, when the coefficients are a = 0.43, b = 0.28, c = 0.46, d = 0.27. The value obtained by subtracting the actual measurement value from the regression line of Bu (7 days) and the activity index is -6.8 to 5.6%, and has a strong correlation with the activity index, and selects good blast furnace slag. It can be used as an indicator.

The blast furnace slag sorting method of the present embodiment is based on the chemical composition of the blast furnace slag, and the basicity Bu (28 days) of the blast furnace slag, which serves as an index of the activity index of cement with a mortar age of 28 days, is expressed by the equation (2). An index calculation process to calculate and a selection process to select blast furnace slag based on the basicity Bu (28 days) as the index.
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)

  In the index calculation step of the present invention, the basicity Bu (28 days) group calculated by the formula (2) has a strong correlation with the activity index of 28 days of mortar material age, and is an index for accurately predicting the activity index. Can be used as In the index calculation step of the present invention, the basicity Bu (28 days) of the blast furnace slag is calculated by the equation (2), and a blast furnace cement having a high activity index is obtained from the value of the basicity Bu (28 days). Blast furnace slag can be sorted out.

In the formula (2), CaO, Al ₂ O ₃ , MgO, SiO ₂ , TiO ₂ and MnO are the contents of each chemical component in the blast furnace slag. In the formula (2), a is 0.05 to 0.65, preferably a is 0.25 to 0.55, more preferably a is 0.35 to 0.50, and most preferably a is 0.00. 37-0.50. In formula (2), b is −0.40 to 0.95, preferably b is −0.30 to 0.90, more preferably b is −0.25 to 0.85, and most preferably b is − 0.25 to 0.31. In formula (2), c is 0.15 to 2.00, preferably c is 0.40 to 1.30, more preferably c is 0.50 to 0.85, and most preferably c is 0.50 to 0.80. In the formula (2), d is 0.05 to 0.95, preferably d is 0.08 to 0.50, more preferably d is 0.10 to 0.25, and most preferably d is 0.10 to 0.10. 0.23.

In the formula (2), the MgO amount coefficient a is 0.05 to 0.65, most preferably a is 0.37 to 0.50, and the Al ₂ O ₃ amount coefficient b is −0.40 to 0.95. Most preferably, b is −0.25 to 0.31, the TiO ₂ amount coefficient c is 0.15 to 2.00, most preferably c is 0.50 to 0.80, and the MnO amount coefficient d is 0. When the mortar age is 28 days, the blast furnace slag can be selected as a cement raw material having an excellent activity index when the d is 0.05 to 0.95, and most preferably d is 0.10 to 0.23. The present invention considers the amount of TiO ₂ and MnO, which are trace amounts of chemical components of blast furnace slag, and reviews the influence of the amount of MgO and Al ₂ O ₃ on the activity index of blast furnace cement. We have found a new index for accurate prediction. In the formula (2) for deriving the basicity Bu (28 days), the present invention takes into consideration the influence of the TiO ₂ content and MnO content of the blast furnace slag on the activity index of cement, and the coefficient c of TiO ₂ and MnO A new quantity coefficient d has been found. In addition, the present invention reviews the influence of the amount of MgO and Al ₂ O ₃ in the blast furnace slag on the activity index of the cement in Formula (2) for deriving the basicity Bu (28 days). The coefficient a of MgO amount and the coefficient b of Al ₂ O ₃ amount for predicting well were newly found. In the present invention, the basicity Bu (28 days) of blast furnace slag having a strong correlation with the activity index of 28 days of mortar material can be calculated by the formula (2), and the basicity Bu (28 days) of this blast furnace slag is calculated. ) As an index, good blast furnace slag can be selected as a raw material for cement having an excellent activity index.

  MnO in the blast furnace slag contributes to a decrease in the activity of the blast furnace slag. When the coefficient d of the MnO amount of the blast furnace slag in the formula (2) is 0.05 to 0.95, the influence of the MnO amount contributing to the activity reduction of the blast furnace slag on the activity index of the mortar material age 28 days In consideration, the basicity Bu (28 days) of the blast furnace slag having a strong correlation with the activity index and the smallest variation in the activity index can be derived. The coefficient d of the MnO amount of the blast furnace slag of the formula (2) is a value smaller than the coefficient of the MnO amount in the index (Bm) calculated by the conventional formula (A).

TiO ₂ in the blast furnace slag contributes to a decrease in the activity of the blast furnace slag. When the coefficient c of the TiO ₂ amount of the blast furnace slag in the formula (2) is 0.15 to 2.00, the TiO ₂ amount contributing to the activity reduction of the blast furnace slag to the activity index of the mortar material age 7 days Considering the influence, it is possible to derive the basicity Bu (28 days) of blast furnace slag which has a strong correlation with the activity index and minimizes the variation of the activity index. Effect on the activity index of the TiO ₂ content in the blast furnace slag is large, the coefficient c of the TiO ₂ amount of blast furnace slag of formula (2) is, TiO ₂ in the index (Bm) calculated by the conventional formula (A) It is a value larger than the coefficient of quantity.

MgO in the blast furnace slag contributes to improving the activity of the blast furnace slag. When the coefficient a of the MgO amount of the blast furnace slag in the formula (2) is 0.05 to 0.65, the influence of the MgO amount contributing to the activity improvement of the blast furnace slag on the activity index of the mortar material age 28 days In consideration, the basicity Bu (28 days) of the blast furnace slag having a strong correlation with the activity index and the smallest variation in the activity index can be derived. Coefficients of the coefficient a of MgO amount of blast furnace slag, JIS basicity calculated from the conventional equation (S) _{(B JIS)} or MgO amount in the index (Bm) calculated by the equation (A) of formula (2) Is a smaller value.

Al ₂ O ₃ in the blast furnace slag contributes to improving the activity of the blast furnace slag. When the coefficient b of the Al ₂ O ₃ amount of the blast furnace slag in the formula (2) is −0.40 to 0.95, the mortar age of 28 days of the Al ₂ O ₃ amount contributing to the activity improvement of the blast furnace slag Considering the influence on the activity index, it is possible to derive the basicity Bu (28 days) of the blast furnace slag which has a strong correlation with the activity index and minimizes the variation of the activity index. The coefficient b of the Al ₂ O ₃ amount of the blast furnace slag of the formula (2) is the Al in the index (Bm) calculated by the JIS basicity (B _JIS ) calculated by the conventional formula (S) or the formula (A). It is a value smaller than the coefficient of ₂ O ₃ amount.

  For example, the abscissa represents the basicity Bu (28 days) calculated when the coefficients of the equation (2) are a = 0.42, b = −0.16, c = 0.60, d = 0.14. In addition, the value obtained by subtracting the actual measurement value from the regression line when the activity index on the mortar age of 28 days is plotted on the vertical axis is -5.2 to 5.2%, and Bu has a strong correlation with the activity index. Show.

  The basicity Bu (28 days) calculated by the formula (2) is preferably −0.20 to 1.70. The basicity Bu (28 days) calculated by the formula (2) is more preferably 0.60 to 1.30, further preferably 0.65 to 1.20, and particularly preferably 0.65 to 1.10. is there. When the basicity Bu (28 days) calculated by the formula (2) is more preferably 0.65 to 1.20, there is a strong correlation between the activity index of cement and the basicity of blast furnace slag, and high activity As a raw material for obtaining cement having a high quality, it is possible to select a blast furnace slag having a good quality and homogeneous.

When the basicity Bu (28 days) calculated by the formula (2) is −0.20 to 1.70, CaO / SiO ₂ , MgO / SiO ₂ , Al ₂ O ₃ / SiO ₂ , TiO ₂ , each term of MnO is an independent variable, and the coefficient of MgO in equation (2), the coefficient b of Al ₂ O ₃ , and TiO ₂ The coefficient c and the coefficient d of MnO can be determined. The basicity Bu (28 days) calculated by the equation (2) is, for example, when the coefficients are a = 0.42, b = −0.16, c = 0.60, d = 0.14. The value obtained by subtracting the actual measurement value from the regression line of the degree Bu (28 days) and the activity index is -5.2 to 5.2%, and has a strong correlation with the activity index, and selects good blast furnace slag. It can be used as an index to do.

  In the sorting step of the present invention, blast furnace slag can be sorted based on the basicity Bu (7 days) calculated by the equation (1) or the basicity Bu (28 days) calculated by the equation (2). . From the basicity Bu (7 days) calculated by the equation (1) or the basicity Bu (28 days) calculated by the equation (2), the activity index of the cement using the blast furnace slag can be predicted, Blast furnace slag can be selected as a raw material for cement having a high activity index. According to the sorting step of the present invention, it is possible to sort out blast furnace slag with good quality and homogeneity. The selection of the blast furnace slag in the selection process includes sampling a desired blast furnace slag, obtaining the basicity Bu, and then selecting a blast furnace slag of the same lot as the blast furnace slag having a good basicity Bu. It is done.

<Manufacturing method of blast furnace cement>
Next, the manufacturing method of the blast furnace cement of this invention is demonstrated.
The manufacturing method of the blast furnace cement should just go through the same process as the screening method of the blast furnace slag mentioned above until the selection process.

In the present invention, the basicity Bu (7 days) of blast furnace slag, which serves as an index of the activity index of a 7-day-old cement, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
An index calculation process calculated by the above, a selection process for selecting blast furnace slag based on the basicity Bu (7 days) as an index, and a manufacturing process for manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement including.

  In the method for producing a blast furnace cement of the present invention, the basicity Bu (7 days) of the blast furnace slag calculated by the formula (1) is any value of 0 to 1.70, and the base of the blast furnace slag is calculated in the selection step. Blast furnace slag with a degree of basicity Bu (7 days) or higher is selected as a high activity blast furnace slag, and blast furnace slag with a basicity Bu (7 days) value is selected as a low activity blast furnace slag. Process. According to the method for producing a blast furnace cement of the present invention, according to the activity index required for the blast furnace cement, the blending amount of the high activity blast furnace slag and the low activity blast furnace slag is adjusted, and the required activity is obtained. A blast furnace cement having an index can be produced. For example, the basicity Bu (7 days) calculated by the formula (1) is any value from 0 to 1.70, and the low activity blast furnace slag having a basicity less than this value is represented by the basicity Bu ( It can be used by mixing with high activity blast furnace slag having a basicity equal to or higher than the value of 7 days).

In the present invention, the basicity Bu (28 days) of blast furnace slag, which serves as an index of the activity index of cement with a mortar age of 28 days, is expressed by the following formula (2).
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)
An index calculation process calculated by the above, a selection process of selecting blast furnace slag based on the basicity Bu (28 days) as an index, and a manufacturing process of manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement including.

  In the method for producing a blast furnace cement according to the present invention, the basicity Bu (28 days) of the blast furnace slag calculated by the equation (2) is any value of −0.20 to 1.70. Blast furnace slag whose basicity of slag is more than the value of basicity Bu (28 days) is selected as high activity blast furnace slag, and blast furnace slag whose basicity is less than the value of Bu (28 days) is selected as low activity blast furnace slag. Including the step of sorting as According to the method for producing a blast furnace cement of the present invention, according to the activity index required for the blast furnace cement, the blending amount of the high activity blast furnace slag and the low activity blast furnace slag is adjusted, and the required activity is obtained. A blast furnace cement having an index can be produced. For example, the basicity Bu (28 days) calculated by the formula (2) is any value of −0.20 to 1.70, and the low activity blast furnace slag having a basicity less than this value is a base It can be used by mixing with high activity blast furnace slag having a basicity equal to or higher than the value of degree Bu (28 days).

  Embodiments of the cement production process of the present invention include a method of pulverizing a selected blast furnace slag and then mixing the cement to produce a blast furnace cement, and simultaneously mixing and pulverizing the selected blast furnace slag and cement. Examples include a method for producing blast furnace cement. In the cement manufacturing process, the mortar activity index can be adjusted by adjusting the amount of blast furnace slag mixed with cement.

  The method for producing a blast furnace cement according to the present invention further includes a strength complementation step, so that the strength development of the blast furnace cement can be further enhanced, and blast furnace slag having a low basicity Bu can be effectively used. As the strength complementation step, a step of adjusting the fineness of blast furnace slag, a step of adjusting the fineness of Portland cement, a step of adjusting the fineness of blast furnace cement, a step of adjusting the addition amount of an inorganic substance containing chlorine, There are a step of adjusting the addition amount of gypsum, a step of adjusting the addition amount of limestone, and the like, and two or more of these can be combined. Various fine grinding methods can be used for adjusting the fineness, and for example, a tube mill, a vibration mill, a vertical mill, or the like can be used.

The inorganic substance containing chlorine includes chlorine such as chlorine bypass dust, electrostatic dust collection dust, NaCl, KCl, and CaCl ₂ .
The amount of the inorganic substance added is preferably such that the chlorine content in the blast furnace cement is 30 to 350 mg / kg, more preferably 40 to 320 mg / kg, still more preferably 50 to 300 mg / kg, and particularly preferably 60 to 250 mg / kg. Adjust so that

The blast furnace cement obtained by the method for producing a blast furnace cement of the present invention has a Blaine specific surface area of preferably 3000 to 4800 cm ² / g, more preferably 3100 to 4700 cm ² / g, still more preferably 3200 to 4600 cm ² / g, particularly Preferably it is 3300-4500 cm < ² > / g.
Brain specific surface area of blast furnace cement affects strength development, by sufficiently grinding so that the brane specific surface area of blast furnace cement obtained by the production method of the present invention is more preferably 3200-4600 cm ² / g, A blast furnace cement having a good activity index can be obtained.

In the method for producing a blast furnace cement of the present invention, various Portland cements can be used as cement to be mixed with the blast furnace slag. However, it is preferable to use ordinary Portland cement because of easy availability. The lower limit of the Blaine specific surface area of the cement, from the viewpoint of strength development, preferably 2800 cm ² / g, more preferably 3000 cm ² / g, more preferably 3300 cm ² / g, particularly preferably 3500 cm ² / g is there. The upper limit of the Blaine specific surface area of the cement, from the viewpoint of fluidity retention, preferably 5000 cm ² / g, more preferably 4500cm ² / g, particularly preferably 4000 cm ² / g.

From the viewpoint of strength development, the blast furnace cement obtained by the method for producing a blast furnace cement of the present invention preferably has a lower limit of the brane specific surface area of the blast furnace slag, preferably 3000 cm ² / g, more preferably 3500 cm ² / g, still more preferably. It is 4100 cm ² / g, particularly preferably 4300 cm ² / g. From the viewpoint of maintaining fluidity, the upper limit is preferably 9000 cm ² / g, more preferably 7000 cm ² / g, still more preferably 5000 cm ² / g, and particularly preferably 4600 cm ² / g.

  The method for producing a blast furnace cement of the present invention may include a step of producing a cement clinker, and a step of mixing a cement clinker, gypsum and blast furnace slag and pulverizing to obtain a cement. The blast furnace slag used in the process of obtaining cement was selected using the basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) as an index. Excluding slag.

Blast furnace cement obtained by the production method of the blast furnace cement of the present invention, 1.4 to 2.3% amount of gypsum in the SO ₃ basis, preferably 1.45 to 2.0 wt%, more preferably 1. It is 5-1.8%, More preferably, it is 1.55-1.7 mass%. If it is this range, the blast furnace cement which is excellent in intensity | strength expression can be provided.

  As a method for producing a blast furnace cement of the present invention, a small amount of a mixture may be added in the step of mixing cement clinker, gypsum and blast furnace slag. The mixed material is a blast furnace slag defined in JIS R 5211 “Blast Furnace Cement”, a siliceous mixed material defined in JIS R 5212 “Silica Cement”, fly ash defined in JIS A 6201 “Fly Ash for Concrete”, Limestone as defined in JIS R 5210 “Portland cement” can be used.

  In the blast furnace cement obtained by the method for producing a blast furnace cement of the present invention, the amount of limestone added is 1 to 6% by mass, preferably 1.5 to 5.5% by mass, more preferably 2 to 5% by mass, and still more preferably. It is 2.5-4.5 mass%. If it is this range, the blast furnace cement which is excellent in intensity | strength expression can be provided.

  The cement clinker is manufactured by mixing raw materials selected from the group consisting of limestone, meteorite, coal ash, clay, blast furnace slag, construction generated soil, sewage sludge, copper squeeze and incinerated ash, and firing to produce a cement clinker. To do.

  The cement clinker can be manufactured using an existing cement manufacturing facility such as an SP system (multistage cyclone preheating system) or an NSP system (multistage cyclone preheating system provided with a calcining furnace).

  The method of mixing the cement clinker, gypsum, blast furnace slag and a small amount of the mixture of the present invention is not particularly limited, and a method of mixing and pulverizing cement clinker, gypsum and blast furnace slag, cement clinker and gypsum Examples of the method include mixing with pulverized slag after mixing and pulverization.

  The contents of the present invention will be described in detail below with reference to examples and comparative examples. Note that the present invention is not limited to these examples.

○ Evaluation with trial slag Manufacture of trial granulated slag The granulated slag from which the chemical component shown in Table 1 differs was heated and produced with the electric furnace. The chemical component of Table 1 is the quantity (mass%) of the reagent for manufacturing granulated slag. Reagents are used as raw materials for granulated slag (CaCO ₃ , Al ₂ O ₃ , SiO ₂ , Fe ₂ O ₃ , MgO, TiO ₂ , MnO, Na ₂ O, K ₂ O), and the prepared raw materials are placed in a carbon crucible. After putting in a carbon lid and decarboxylating at 1000 ° C. for 15 minutes, the temperature was raised to 1500 ° C. at 50 ° C./min and heated at that temperature for 30 minutes. Thereafter, the melted sample was poured into water to obtain a granulated slag. The granulated slag taken out from the water was dried at 105 ° C. and pulverized with a ball mill so that the specific surface area of the brain was 4300 ± 100 cm ² / g. The produced granulated slag was a trial slag.
In this example, the chemical component of the trial slag shows the amount (% by mass) of the reagent in Table 1, but the content of the chemical component of the granulated slag is JIS R 5202 “Method for chemical analysis of Portland cement” or JIS. It can be measured in accordance with R 5204 “Method for fluorescent X-ray analysis of cement”.

2. Production of Blast Furnace Cement Using Trial Slag Each trial slag and commercially available Portland cement were mixed at a ratio of 1: 1 to produce each blast furnace cement. Blast furnace cement has a Blaine specific surface area of 4300 ± 100 cm ² / g.

3. Mortar activity index Mortar was produced by adding sand and water to blast furnace cement produced using each trial slag and mixing them. As the sand, standard sand for cement test was used. Tap water was used as water. Mortar was manufactured by blending 450 g of blast furnace cement, 1350 g of sand, and 225 g of water. The activity index of 7-day mortar and 28-day mortar is the activity index by mortar of blast furnace slag fine powder described in the appendix of JIS A 6206: 2013 "Blast furnace slag fine powder for concrete" It was measured according to “Test method of flow value ratio”. The results are shown in Table 1.

Based on each chemical component of each trial slag, each term of CaO / SiO ₂ , MgO / SiO ₂ , Al ₂ O ₃ / SiO ₂ , TiO ₂ , MnO is an independent variable, and the activity index of mortar material age 7 days or A multiple regression analysis was performed with the activity index of mortar age 28 days as a dependent variable. The coefficients of the terms of the independent variable determined from the multiple regression analysis, dividing the coefficients of all the terms in the coefficient of CaO / SiO _2, the value (CaO + a × MgO + b × Al 2 O 3) / SiO 2 -c × The coefficient of TiO ₂ -d × MnO was determined by dividing the mortar material age of 7 days or the mortar material age of 28 days, respectively. Formula (1) calculated | required the coefficient of each chemical component from the multiple regression analysis using the activity index of the mortar material age 7 days. Formula (2) calculated | required the coefficient of each chemical component from the multiple regression analysis using the activity index of the mortar material age 28 days. The basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) is a JIS base calculated by the formula (S) defined in JIS A 6202. In these blast furnace slag, the coefficient a of MgO, the coefficient b of Al ₂ O ₃ and the MnO coefficient d are smaller than the basicity (Bm) calculated by the degree (B _JIS ) and the conventional formula (A). The chemical component has a small effect on the activity index. The basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) is the basicity (Bm) calculated by the conventional formula (A). Since the coefficient c of TiO ₂ is larger than that, the influence on the activity index of TiO _{2 in} the blast furnace slag is large.

Bu (7 days) = (CaO + 0.43 × MgO + 0.28 × Al ₂ O ₃ ) / SiO ₂ −0.46 × TiO ₂ −0.27 × MnO (1 ′)
Bu (28 days) = (CaO + 0.42 × MgO−0.16 × Al ₂ O ₃ ) / SiO ₂ −0.60 × TiO ₂ −0.14 × MnO (2 ′)

For the trial slag, the basicity Bu (7 days) was determined from the content of each chemical component of the trial slag and the formula (1 ′). Moreover, the trial manufacture slag calculated | required basicity Bu (28 days) from content of each chemical component of trial manufacture slag, and Formula (2 '). In addition, the trial slag is based on the content of each chemical component of the trial slag and the respective formulas, JIS basicity (B _JIS ) by formula (S), index (Bm) by formula (A), and base by formula (B). Degree (B _B ), basicity (B _C ) according to formula ( _C ), basicity (B _D ) according to formula ( _D ), basicity (B _F7 ) of mortar material age 7 days according to formula ( _F ), The basicity (B _F28 ) of mortar material age 28 days was determined by _F ). Table 2 shows the basicity of each trial slag calculated by each formula.

JIS basicity (B _JIS ) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ (S)
Index (Bm) = (CaO + MgO + Al ₂ O ₃ ) / SiO ₂ −0.13 × TiO ₂ —MnO (A)
Basicity (B _B ) = CaO + (2/3) × MgO—SiO ₂ —Al ₂ O ₃ (B)
Basicity (B _C ) = (CaO + 0.7 × MgO) / (0.94 × SiO ₂ + 0.18 × Al ₂ O ₃ ) (C)
Basicity (B _D ) = (CaO + Al ₂ O ₃ + MgO + Na ₂ O + S) / (SiO ₂ + TiO ₂ ) (D)
Basicity (B _E ) = (CaO + MgO + (1/3) × Al ₂ O ₃ ) / (SiO ₂ + (2/3) × Al ₂ O ₃ ) (E)
Basicity (B _F7 ) = (Kc × CaO + Ka × Al ₂ O ₃ + Km × MgO + Kn × Na ₂ O + Ksu × S) / (SiO ₂ + Kt × TiO ₂ ) (F)
(However, when the material is 7 days old, Kc is 1.42, Ka is 1.29, Km is 1.75, Kt is 4.99, Kn is 3.33, and Ksu is 2.69.)
Basicity (B _F28 ) = (Kc × CaO + Ka × Al ₂ O ₃ + Km × MgO + Kn × Na ₂ O + Ksu × S) / (SiO ₂ + Kt × TiO ₂ ) (F)
(However, when the age is 28 days, Kc is 0.24, Ka is 0.42, Km is 0.23, Kt is 2.63, Kn is 0.99, and Ksu is 0.45.

FIG. 1 shows the relationship between the basicity Bu (7 days) of each trial slag calculated by the formula (1 ′) of the present invention and the activity index of the mortar material age 7 days, and the formula (2 ′) of the present invention. It is a graph which shows the basicity Bu (28 days) of each trial manufacture slag calculated, and the relationship between the activity index of the mortar material age 28 days.
As shown in FIG. 1, the basicity Bu (7 days) calculated by the equation (1 ′) and the activity index of the mortar material age 7 days are obtained by subtracting the measured value from the regression line to −6. It is 8 to 5.6%, and has a strong correlation with the activity index. Using the basicity Bu (7 days) calculated by the formula (1) of the present invention as an index, the activity of the mortar material age 7 days is accurate. The index could be predicted, and it was confirmed that a good blast furnace slag usable as a cement raw material having an excellent activity index could be selected.
As shown in FIG. 1, the basicity Bu (28 days) calculated by the equation (2 ′) and the activity index of the mortar material age 28 days are obtained by subtracting the actual measurement value from the regression line to −5. It is 2 to 5.2%, and has a strong correlation with the activity index, and the activity of mortar material age 28 is accurately determined using the basicity Bu (28 days) calculated by the formula (2) of the present invention as an index. The index could be predicted, and it was confirmed that a good blast furnace slag usable as a cement raw material having an excellent activity index could be selected.

FIG. 2 is a graph showing the relationship between the JIS basicity (B _JIS ) calculated by the formula (S), the activity index of mortar material age 7 days, and the activity index of mortar material age 28 days.
In the relationship between the JIS basicity (B _JIS ) calculated by the formula (S) and the activity index of mortar material age 7 days or the activity index of mortar material age 28 days, the data circled in FIG. JIS basicity _{(B JIS)} activity index of the active index or mortar ages 28 days the mortar ages 7 days with respect to low, large variations in JIS basicity and _{(B JIS)} and activity index, JIS The activity index cannot be predicted from the basicity (B _JIS ), and the blast furnace slag used as a raw material for the blast furnace cement showing the required activity index is expressed by the formula (S) as JIS basicity (B _JIS ). It may not be possible to sort based on this.

FIG. 3 is a graph showing the relationship between the index (Bm) calculated by the formula (A), the activity index of mortar material age 7 days and the activity index of mortar material age 28 days.
In the relationship between the index (Bm) calculated by the formula (A) and the activity index of the mortar material age 7 days or the activity index of the mortar material age 28 days, the data circled in FIG. ) The index of activity (Bm) calculated by the formula (A) is higher than the index of activity (Bm) calculated by the formula (A). The activity index cannot be accurately predicted from the index (Bm) calculated by the formula (A), and the blast furnace slag used as a raw material for the blast furnace cement showing the required activity index is expressed by the formula (A ) May not be selected based on the index (Bm) calculated by (1).

FIG. 4 is a graph showing the relationship between the basicity (B _B ) calculated by the formula (B), the activity index at 7 days of mortar material, and the activity index at 28 days of mortar material.
As shown in FIG. 4, the basicity (B _B ) calculated by the equation (B) and the activity index of the mortar material age 7 days are values obtained by subtracting the actual measurement value from the regression line from −11.7 to 18.7%, -6.3 to 14.8% at the age of 28 days, and the variation between the basicity (B _B ) calculated by the formula ( _B ) and the activity index is The basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) of the present invention is larger than the basicity (B _The activity index cannot be accurately predicted from _B ), and the blast furnace slag used as the raw material for the blast furnace cement showing the required activity index cannot be selected based on the basicity (B _B ) calculated by the formula (B). There is a case.

FIG. 5 is a graph showing the relationship between the basicity (B _C ) calculated by the formula (C), the activity index of the mortar material age 7 days, and the activity index of the mortar material age 28 days.
As shown in FIG. 5, the basicity (B _C ) calculated by the formula (C) and the activity index of the mortar material age 7 days are values obtained by subtracting the actual measurement value from the regression line from −9.9 to 18.8%, -6.4 to 14.8% at the age of 28 days, and the variation between the basicity (B _C ) calculated by the formula ( _C ) and the activity index is The basicity Bu (7 days) calculated by the equation (1) or the basicity Bu (28 days) calculated by the equation (2) of the present invention is larger than the basicity (B _The activity index cannot be accurately predicted from _C ), and the blast furnace slag used as the raw material of the blast furnace cement showing the required activity index cannot be selected based on the basicity (B _C ) calculated by the formula (C). There is a case.

FIG. 6 is a graph showing the relationship between the basicity (B _D ) calculated by the formula (D), the activity index of mortar material age 7 days, and the activity index of mortar material age 28 days.
As shown in FIG. 6, the basicity (B _D ) calculated by the formula (D) and the activity index of the mortar material age 7 days are values obtained by subtracting the actual measurement value from the regression line, −8.3 to 8.3. 15.8%, -7.1 to 12.9% at the age of 28 days, and the variation between the basicity (B _D ) calculated by the formula ( _D ) and the activity index is The basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) of the present invention is larger than the basicity (B _The activity index cannot be accurately predicted from _D ), and the blast furnace slag used as the raw material for the blast furnace cement showing the required activity index cannot be selected based on the basicity (B _D ) calculated by the formula (D). There is a case.

FIG. 7 is a graph showing the relationship between the basicity (B _E ) calculated by the formula (E), the activity index of the mortar material age 7 days, and the activity index of the mortar material age 28 days.
As shown in FIG. 7, the basicity (B _E ) calculated by the formula (E) and the activity index of the mortar material age 7 days are values obtained by subtracting the actual measurement value from the regression line, from −10.8 to 18.6%, -6.4 to 14.7% at the age of 28 days, and the variation in basicity (B _E ) calculated by the formula ( _E ) and the activity index is From the basicity Bu (7 days) calculated by the formula (1) or the basicity Bu (28 days) calculated by the formula (2) of the present invention, the basicity (B _E ) of the formula (E) The activity index cannot be accurately predicted, and the blast furnace slag used as the raw material for the blast furnace cement showing the required activity index may not be selected based on the basicity (B _E ) calculated by the formula (E). .

FIG. 8 is a graph showing the relationship between the basicity (B _F7 ) of the mortar material age 7 days and the activity index of the mortar material age 7 days of the formula (F).
As shown in FIG. 8, the basicity (B _F7 ) of the mortar age 7 days calculated by the formula (F) and the activity index of the mortar age 7 days are values obtained by subtracting the actual measurement values from the regression line. Is -7.9 to 8.5%, and the variation between the basicity (B _F7 ) of the mortar material age 7 days calculated by the formula (F) and the mortar activity index is the formula (1) of the present invention. The activity degree which is greater than the basicity Bu (7 days) calculated by the formula (B) and cannot be accurately predicted from the basicity (B _F7 ) of the mortar material age 7 days calculated by the formula (F), and the required activity In some cases, blast furnace slag used as a raw material for blast furnace cement showing an index cannot be selected based on the basicity (B _F7 ) of the mortar material age 7 days calculated by the formula (F).

FIG. 9 is a graph showing the relationship between the basicity (B _F28 ) of the mortar material age 28 days and the activity index of the mortar material age 28 days of the formula (F).
As shown in FIG. 9, the basicity (B _F28 ) of the mortar material age 28 days and the activity index of the mortar material age 28 days of the formula (F) are values obtained by subtracting the actual measurement values from the regression line. The difference between the basicity (B _F28 ) of the mortar material age 28 days of the formula (F) and the mortar activity index of the formula ( _F ) is the basicity Bu (28) of the formula (2) of the present invention. The activity index cannot be accurately predicted from the basicity (B _F28 ) of the mortar material age 28 days of the formula (F), and the blast furnace used as a raw material for the blast furnace cement showing the required activity index In some cases, slag cannot be sorted based on the basicity (B _F28 ) of the mortar age 28 days calculated by the formula (F).

The present invention reviews the influence on the activity index of each chemical component of the blast furnace slag, and each chemical component in the formula (S) for deriving the JIS basicity (B _JIS ) and the formula (A) for deriving the conventional index (Bm) The coefficient a of MgO, the coefficient b of Al ₂ O _{3 and} the coefficient of MnO in the formula (1) for deriving the basicity Bu (7 days) or the formula (2) for deriving the basicity Bu (28 days) It is considered that the accuracy of predicting the activity index of cement using blast furnace slag was increased by reducing d and increasing the coefficient c of TiO ₂ . Further, in the formula ( _B ) for deriving the basicity (B _B ), the formula ( _C ) for deriving the basicity (B _C ), and the formula ( _F ) for deriving the basicity (B _F28 ) of the mortar material age 28 days, Although there are those in which the coefficient of MgO and the coefficient of Al ₂ O ₃ are smaller than 1, the formula (1) for deriving the basicity Bu (7 days) or the formula for deriving the basicity Bu (28 days) of the present invention In (2), by making the coefficient a of MgO and the coefficient b of Al ₂ O ₃ smaller than the conventional formula (B), formula (C) or formula (F), the activity of cement using blast furnace slag The prediction accuracy of degree index could be further improved.

○ Method for producing blast furnace cement using Bu Test method of blast furnace cement mixed with low activity slag and high activity slag As a method for using the selected low activity slag, blast furnace slag (No. 1) with low Bu shown in Table 3 and blast furnace slag with high Bu (Table 3) When No. 2) was mixed at 1: 1 so that Bu (7 days) was 1.00 or more, Bu was 1.07 on 7 days and 0.84 on 28 days, and the activity index was 7 82.5% on the day and 103.0% on the 28th. By combining both the low activity slag and the high activity slag, it is possible to obtain a blast furnace cement having a higher Bu than in the case of the low activity slag alone and having good strength development. Furthermore, by using the basicity Bu, the activity index can be accurately predicted, and the low activity slag can be used more effectively.

2. Improvement of strength of blast furnace cement by various supplementary measures We investigated the effect of various supplementary measures on the strength improvement of blast furnace cement.

2.1 Test method The evaluation is based on the level of separate pulverization in which blast furnace slag powder and Portland cement (NC) are separately manufactured, and the level of mixed pulverization in which blast furnace slag, clinker, gypsum and limestone are mixed and ground simultaneously. evaluated.

Tables 4-7 show the material characters used in this test. Tables 8 and 9 show the blending of materials at the time of separation pulverization and mixed pulverization. A pulverization aid was added to these materials and pulverized with a predetermined ball mill. As a strength supplementary measure, an attempt was made to improve strength by increasing the degree of fineness (separation pulverization: N and slag, mixed pulverization: blast furnace cement), and adding gypsum and limestone. In the mixing and pulverization, the slag was pulverized in advance so that the specific surface area of the brain was 3600 cm ² / g, and mixed with other materials and pulverized. In the case of separation and pulverization, 44.5% by mass of the produced blast furnace slag powder was added to Portland cement.
Using these prepared cements, in accordance with JIS R 5201: 1997 “Physical Test Method for Cement”, preparation of mortar specimens and measurement of compressive strength (material age 7 days, 28 days) were performed. Strength development was evaluated by a ratio with the standard of compressive strength.
The strength development was evaluated by the strength ratio with respect to the reference (No. 1 and No. 9) in separation pulverization and mixed pulverization, respectively.

2.2 Test results (1) Supplementary measures at the time of separation and pulverization Figures 10-12 show the effects of the specific surface area of blast furnace slag or portland cement, respectively (circle plot shows triangle plot when blast furnace slag brain is increased) (Indicates the case of increasing the NC brane), and shows the results of investigating the effects of gypsum addition and limestone addition. By increasing the fineness of slag or NC, the strength development of blast furnace cement increased. In particular, the effect of improving the strength was greater when the fineness of the slag was increased. In addition, the strength development tends to increase as the amount of limestone added increases. The effect of the amount of gypsum added reached a maximum around 1.6% by mass on the basis of SO ₃ .

(2) Supplementary measures at the time of mixing and pulverizing FIGS. 13 to 15 show the results of examining the influence of the Blaine specific surface area of blast furnace cement, the influence of the addition amount of gypsum, and the influence of the addition amount of limestone, respectively. By increasing the degree of fineness, strength development was enhanced. The effect of the amount of gypsum added reached a maximum around 1.6% by mass on the basis of SO ₃ . Moreover, the influence of the limestone addition amount tends to increase the strength development as the addition amount increases, and an excellent strength improvement effect was observed particularly at the age of 7 days.

The present invention reviews the influence of each chemical component of MgO and Al ₂ O ₃ on the activity index together with TiO ₂ and MnO of blast furnace slag, and basicity Bu (which is an index for accurately predicting the activity index Formula (1) for deriving (7 days) or formula (2) for deriving basicity Bu (28 days) is defined, and this basicity Bu (7 days) or basicity Bu (28 days) is used as an index for excellent activity. Blast furnace slag can be selected as a raw material for cement having a degree index, which is industrially useful. Further, the present invention can produce blast furnace cement using the selected blast furnace slag, and is industrially useful.

Claims (14)

The basicity Bu (7 days) of blast furnace slag, which is an index of the activity index of cement with a mortar age of 7 days, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
A method for selecting blast furnace slag, comprising: an index calculation step calculated by the above and a selection step of selecting blast furnace slag based on the basicity Bu (7 days) as an index.   The method for sorting blast furnace slag according to claim 1, wherein the basicity Bu (7 days) calculated by the formula (1) is any value of 0 to 1.70.   In the sorting step, the blast furnace slag whose basicity of the blast furnace slag is equal to or higher than the basicity Bu (7 days) calculated by the formula (1) is sorted as the high activity blast furnace slag, and the formula (1) The method for sorting blast furnace slag according to claim 1 or 2, comprising a step of sorting blast furnace slag having a basicity Bu (7 days) value calculated by the above as low activity blast furnace slag. The basicity Bu (28 days) of blast furnace slag, which is an index of the activity index of cement with a mortar age of 28 days, is expressed by the following formula (2)
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95.)
A method for selecting blast furnace slag, comprising: an index calculation step calculated by the above and a selection step of selecting blast furnace slag based on the basicity Bu (28 days) as an index.   The method for sorting blast furnace slag according to claim 4, wherein the basicity Bu (28 days) calculated by the formula (2) is any value of -0.20 to 1.70.   In the sorting step, the blast furnace slag whose basicity of the blast furnace slag is equal to or higher than the basicity Bu (28 days) calculated by the formula (2) is sorted as the high activity blast furnace slag, and the formula (2) The method for sorting blast furnace slag according to claim 4 or 5, comprising a step of sorting blast furnace slag that is less than the value of basicity Bu (28 days) calculated by the above as low activity blast furnace slag. The basicity Bu (7 days) of blast furnace slag, which is an index of the activity index of blast furnace slag 7 days old, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
An index calculation process calculated by the above, a selection process for selecting blast furnace slag based on the basicity Bu (7 days) as an index, and a manufacturing process for manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement The basicity Bu (7 days) of the blast furnace slag calculated by the formula (1) is any value from 0 to 1.70, and in the sorting step, the basicity of the blast furnace slag is the base Selecting a blast furnace slag having a degree of Bu (7 days) or more as a high activity blast furnace slag and selecting a blast furnace slag having a value less than the basicity Bu (7 days) as a low activity blast furnace slag. A method for producing a blast furnace cement. The basicity Bu (28 days) of blast furnace slag, which is an index of the activity index of cement with a mortar age of 28 days, is expressed by the following formula (2)
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)
An index calculation process calculated by the above, a selection process of selecting blast furnace slag based on the basicity Bu (28 days) as an index, and a manufacturing process of manufacturing the blast furnace cement by mixing the selected blast furnace slag and cement The basicity Bu (28 days) of the blast furnace slag calculated by the formula (2) is any value of −0.20 to 1.70, and in the sorting step, the basicity of the blast furnace slag is The blast furnace slag having a value equal to or higher than the basicity Bu (28 days) is selected as a high activity blast furnace slag, and the blast furnace slag having a value less than the basicity Bu (28 days) is selected as a low activity blast furnace slag. A method for producing a blast furnace cement, comprising a step. An index calculation step for calculating basicity Bu (7 days) or basicity Bu (28 days) of blast furnace slag, and low blast furnace slag based on the basicity Bu (7 days) or basicity Bu (28 days) A method for producing a blast furnace cement, comprising a selection step of selecting active slag and high activity slag, and a mixing step of mixing the low activity slag, the high activity slag and cement,
In the index calculation step, the basicity Bu (7 days) of the blast furnace slag, which is an index of the activity index of the mortar material age 7 days, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)
(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
A step of calculating by
The basicity Bu (28 days) of blast furnace slag, which is an index of the activity index of 28 days of mortar material, is expressed by the following formula (2)
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)
Including at least one of the steps of calculating by
The step of selecting the low activity slag and the high activity slag according to the threshold of basicity Bu (7 days) set in the range of 0 to 1.70; and in the range of -0.2 to 1.70. Including at least one of a step of selecting low-activity slag and high-activity slag according to a threshold of the set basicity Bu (28 days),
The mixing step further includes a step of blending the low activity slag and the high activity slag so that the basicity Bu (7 days) or the basicity Bu (28 days) is equal to or greater than the threshold value. Features
Blast furnace cement manufacturing method. An index calculation step for calculating basicity Bu (7 days) or basicity Bu (28 days) of blast furnace slag, and low from blast furnace slag based on the basicity Bu (7 days) or basicity Bu (28 days). A method for producing a blast furnace cement, comprising a sorting step for sorting activated slag, a mixing step for mixing the low activity slag and cement, and a strength supplementing step,
In the index calculation step, the basicity Bu (7 days) of the blast furnace slag, which is an index of the activity index of the mortar material age 7 days, is expressed by the following formula (1).
Bu (7 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (1)

(In the formula (1), a is 0.05 to 0.65, b is 0.05 to 0.95, c is 0.15 to 2.00, and d is 0.05 to 0.95. .)
A step of calculating by
The basicity Bu (28 days) of blast furnace slag, which is an index of the activity index of 28 days of mortar material, is expressed by the following formula (2)
Bu (28 days) = (CaO + a × MgO + b × Al ₂ O ₃ ) / SiO ₂ -c × TiO ₂ -d × MnO (2)
(However, in Formula (2), a is 0.05-0.65, b is -0.40-0.95, c is 0.15-2.00, d is 0.05-0.95. is there.)
Including at least one of the steps of calculating by
The basicity Bu (7 days) of the low activity slag in the calculation step is any value of 0 to 1.70 or Bu (28 days) is -0.20 to 1.70,
The step of selecting low activity slag by the threshold of basicity Bu (7 days) set in the range of 0 to 1.70; and the basicity Bu set in the range of -0.2 to 1.70. (28 days) characterized by including at least one of the step of selecting low activity slag by the threshold value,
Blast furnace cement manufacturing method.   The strength supplementing step is at least one selected from the group consisting of a step of adjusting the fineness of blast furnace slag, a step of adjusting the fineness of Portland cement, and a step of adjusting the fineness of blast furnace cement. The method for producing a blast furnace cement according to claim 10, comprising a step.   The method for producing a blast furnace cement according to claim 10 or 11, wherein the strength supplementing step includes a step of adjusting an addition amount of an inorganic substance containing chlorine.   The method for producing a blast furnace cement according to any one of claims 10 to 12, wherein the strength complementation step includes a step of adjusting an addition amount of gypsum.   The method for producing a blast furnace cement according to any one of claims 10 to 13, wherein the strength supplementing step includes a step of adjusting the amount of limestone added.

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