CN115819008B - High-activity low-shrinkage composite mineral admixture and preparation method thereof - Google Patents

Abstract

The invention discloses a high-activity low-shrinkage composite mineral admixture and a preparation method thereof, and relates to the technical field of concrete mineral admixtures. The composite mineral admixture of the invention comprises the following raw material components in percentage by weight: 15-25% of lithium slag, 30-50% of granulated electric furnace phosphorus slag, 10-20% of ferrovanadium slag, 10-15% of nickel slag, 5-10% of sulphoaluminate cement clinker, 0.5-1.0% of superplasticizer and 0.3-0.5% of early strength grinding aid. The admixture fully plays the synergistic and complementary roles of different types of smelting slag and raw materials, and realizes the shrinkage resistance and higher activity of the composite mineral admixture from early stage to later stage.

Description

A kind of high activity, low shrinkage composite mineral admixture and preparation method thereof

technical field

The invention relates to the technical field of concrete mineral admixtures, in particular to a high-activity, low-shrinkage composite mineral admixture and a preparation method thereof.

Background technique

Concrete shrinkage cracking is a common problem in construction engineering, which will not only reduce the bearing capacity of concrete structures but also affect the safety and durability of the main body of the structure. The aggregate volume stability in concrete is excellent, and the cause of shrinkage cracking is mainly the matrix part. This is not only related to shrinkage of cement-based materials due to moisture migration, but also to cement hydration. After the hydration reaction of Portland cement, the sum of the volume of the reaction product and the remaining free volume is less than the volume before the reaction, resulting in shrinkage. The volume shrinkage rate is usually between 2.3% and 5.1%, which is caused by the shrinkage of cement-based materials and One of the main causes of shrinkage cracks. Mineral admixture is an auxiliary cementitious material that can partially replace cement. When it is mixed with cement, it can react with cement and cement hydration products, and then affect cement-based materials at different levels, thereby realizing the improvement of cement-based materials. Regulation of shrinkage and other properties.

At the same time, due to natural resources and geographical factors in Southwest my country, the amount of traditional mineral admixtures such as fly ash is relatively small, but due to the rich resources of phosphorus, lithium, vanadium and titanium in the region, related resource industries have been formed and lithium is a by-product. Slag, granulated electric furnace phosphorus slag, vanadium iron slag and other industrial smelting slag. The preparation of the above bulk industrial slag as mineral admixture can effectively make up for the shortage of granulated blast furnace slag powder and fly ash. However, due to the unique phase and chemical composition of these industrial smelting slags, the powders formed by processing have special properties, and some of them have poor physical and chemical properties. Although they have certain hydration activity, they are difficult to use directly as mineral admixtures.

Therefore, to realize the resource utilization of industrial smelting slag in Southwest China and the regulation and control of shrinkage of cement-based materials, the present invention intends to use industrial smelting slag such as lithium slag, granulated electric furnace phosphorus slag, vanadium-iron slag, nickel slag and other materials to prepare composite materials. The mineral admixture fully exerts the synergistic and complementary effects of different types of materials to form a high-activity, low-shrinkage composite mineral admixture formula and a preparation method thereof.

In view of this, this application is proposed.

Contents of the invention

The problem of the prior art lies in the high shrinkage of existing mineral admixtures. The purpose of the present invention is to provide a high-activity, low-shrinkage composite mineral admixture, using lithium slag, granulated electric furnace phosphorus slag, vanadite ore Slag, nickel slag and other industrial smelting slags are used to prepare composite mineral admixtures, and the synergistic and complementary effects of different types of smelting slags are fully utilized to form a high-activity, low-shrinkage composite mineral admixture.

The present invention realizes through following technical scheme:

A high-activity, low-shrinkage composite mineral admixture, including the following raw material components: lithium slag, granulated electric furnace phosphorus slag, nickel slag, vanadium iron slag, sulphoaluminate cement clinker, grinding aid, superplastic agent.

The present invention uses lithium slag, nickel slag, granulated electric furnace phosphorus slag, vanadium-iron slag, and sulphoaluminate cement clinker as mineral admixtures, fully exerting the synergistic and complementary effects of different types of smelting slag and clinker, and can Overcoming the performance defects of single use of smelting slag can improve the activity of mineral admixtures and reduce shrinkage.

Further, the chemical composition of the granulated electric furnace phosphorus slag used in the present invention is P ₂ O ₅ ≤3.5%, the mass coefficient K≥1.0, the glass phase content in the granulated electric furnace phosphorus slag is ≥80%, and the granulated electric furnace phosphorus slag The internal illumination index I _Ra ≤1.5, and the external illumination index I _γ ≤1.5.

The present invention limits the P ₂ O ₅ of the granulated electric furnace phosphorus slag used to ≤3.5%. The soluble phosphorus in the phosphorus slag will greatly prolong the setting time of the cement-based material slurry, and will prolong the time of the mixture slurry in the plastic stage, resulting in The plastic shrinkage increases, so the influence of soluble phosphorus on the setting time can be effectively reduced by limiting the content of P ₂ O ₅ . Because the radioactivity of phosphate rock used in phosphorus slag in Southwest China is generally high, the radioactivity of phosphorus slag is relatively high. Therefore the present invention limits phosphorus slag internal exposure index I _Ra ≤ 1.5, external illumination index I _γ ≤ 1.5, and other raw materials used in the present invention are low in radioactivity simultaneously, therefore above-mentioned limitation, both can make the compound mineral admixture performance radioactive property of the present invention satisfy << The requirements of GB6566-2010 "Radionuclide Limits for Building Materials" have expanded the scope of phosphorus slag that can be used as resources.

Further, the lithium slag is a by-product of lithium smelting by the sulfuric acid method, its SiO ₂ +Al ₂ O ₃ content is ≥ 65%, the SO ₃ content is ≥ 5% and ≤ 10.0%, and the water demand ratio is ≤ 115%. The illumination index I _Ra ≤0.6, and the external illumination index I _γ ≤0.6.

The invention limits the lithium slag used to be the lithium slag produced by the sulfuric acid process to smelt lithium, and this type of lithium slag has better activity than the lithium slag obtained by the alkaline process. SO in the present invention is one of the main reactants of ettringite, the early expansion source of the cementitious material system. The cement mineral tricalcium aluminate will react to generate ettringite under the condition of sufficient gypsum, and _this process will produce about 125% of the volume Expansion can help reduce the shrinkage of the system. Limiting SO ₃ in lithium slag can effectively guarantee the anti-shrinkage ability of composite mineral admixtures. The present invention also limits the water demand ratio of lithium slag to ≤115%, which can reduce the negative impact of lithium slag on the fluidity of the composite mineral admixture. The invention limits the lithium slag internal illumination index I _Ra ≤ 0.6 and external illumination index I _γ ≤ 0.6, which provides conditions for the radioactivity of the composite mineral admixture to be qualified.

Further, the ferrovanadium slag is ferrovanadium slag by-product of producing vanadium-titanium alloy by the aluminothermic process, its calcium oxide content is ≥50%, the magnesium oxide content is 5%~15.0%, and the internal illumination index I _Ra ≤0.6 , External illumination index I _γ ≤0.6.

The present invention limits the ferrovanadium slag used to be ferrovanadium slag, a by-product of the production of vanadium-titanium alloy by the aluminothermic process, free calcium oxide and magnesium oxide components exist in the ferrovanadium slag, and simultaneously limits the calcium oxide content in the ferrovanadium slag used to be ≥ 50%. , the magnesium oxide content is 5%~15%, this is because the free calcium oxide component and the magnesium oxide component can expand during the hydration process, which can partially offset the volume shrinkage of the cement-based material in the middle and later stages. The invention limits the internal illumination index I _Ra ≤ 0.6 and the external illumination index I _γ ≤ 0.6 of the ferrovanadium slag, which provides conditions for the qualified radioactivity of the composite mineral admixture.

Further, the nickel slag is the waste slag discharged from the production of non-ferrous metal nickel, its magnesium oxide content is ≥30% and ≤50%, the internal illumination index I _Ra ≤0.6, and the external illumination index I _γ ≤0.6.

The nickel slag used in the present invention is the waste slag discharged from the production of non-ferrous metal nickel, and the content of magnesium oxide is limited to ≥30% and ≤50%. Possess good post-expansion ability. The invention limits the nickel slag internal illumination index I _Ra ≤ 0.6 and external illumination index I _γ ≤ 0.6, which provides conditions for the radioactivity of the composite mineral admixture to be qualified.

Further, the admixture also includes a grinding aid, the grinding aid is an early-strength grinding aid, and the superplasticizer is a high-performance polycarboxylic acid solid powder, and its water content is ≤5%. Water rate ≥ 35%.

Further, a high-activity, low-shrinkage composite mineral admixture of the present invention includes the following raw material components in weight percentages: lithium slag 15%-25%, granulated electric furnace phosphorus slag 30%-50%, vanadium-iron slag 10%~20%, nickel slag 10%~15%, sulphoaluminate cement clinker 5%~10%, superplasticizer 0.5~1.0‰, early strength grinding aid 0.3~0.5‰.

The content of the lithium slag in the composite mineral admixture of the present invention is 15%-25%, that is, the lithium slag powder, as a secondary component of the composite mineral admixture, accounts for 15%-25%. On the one hand, lithium slag itself has high activity; on the other hand, the high content of gypsum phase in lithium slag can not only play the role of sulfate to stimulate the activity of phosphorus slag powder, but also can be combined with sulfoaluminic acid. Salt cement clinker and cement react to form ettringite. This reaction occurs in the early stage of cement paste hardening and is accompanied by volume expansion, which can effectively reduce the early volume shrinkage of early cement paste. At the same time, lithium slag is used as a silicon-aluminum mineral admixture, and phosphorus slag and vanadium-iron slag are calcium-silicon mineral admixtures. The incorporation of lithium slag can effectively make up for the lack of silicon-aluminum components in the system. Give full play to the synergy and complementarity of different slags.

The ferrovanadium slag of the present invention has a content of 10% to 20% in the composite mineral admixture. The present invention adopts 10%~20% ferrovanadium slag, which contains expansion components free calcium oxide and magnesium oxide, and free calcium oxide can react with water to generate calcium hydroxide after hardening with cement and accompany the volume Expansion can achieve the effect of reducing shrinkage in the middle of the system. Magnesium oxide in ferrovanadium slag also has the characteristics of delayed hydration reaction in hardened cement paste, and can play an anti-shrinkage effect in the later stage of hardened cement paste. In addition, from the perspective of activity, the content of vanadium-iron slag limited by the present invention is also related to its low activity index, and an excessively high content will significantly reduce the activity of the composite mineral admixture. At the same time, the hydration mechanism of ferrovanadium slag is different from that of lithium slag and phosphorus slag. Its hydration activity mainly comes from the hydration reaction of its mineral phase such as dicalcium silicate, while lithium slag and phosphorus slag in the composite mineral admixture react with hydrogen Calcium oxide reacts to gain hydration activity, so there is no competition between the two parties.

The content of the nickel slag in the present invention is 10%-15% in the composite mineral admixture. The present invention uses 10%~15% nickel slag because magnesium oxide is the anti-shrinkage component in the late stage of the system, and the content of magnesium oxide in the ferrovanadium slag is about 10%, and the content of magnesium oxide is relatively low, which provides anti-shrinkage components for the late stage of the system. The shrinkage ability is relatively limited, and the magnesium oxide content in nickel slag is about 30%~40%, which can make up for the magnesium oxide content in the system. It can combine with water to form magnesium hydroxide in the later stage of hydration, and there is a volume expansion of 2.48 times. Can effectively reduce system shrinkage.

The present invention limits the content of granulated electric furnace phosphorus slag in the composite mineral admixture to 30% to 50%, because after the phosphorus slag is processed into powder, its 28d activity index can be ≥ 90%, and the fluidity ratio can be ≥ 100%. Because the radioactivity of granulated electric furnace phosphorous slag in Southwest China is generally high, the basic mechanical and working properties of the composite mineral admixture are guaranteed at the above dosage, and the deterioration of the composite mineral admixture due to the high radioactivity of the phosphorous slag can also be avoided. Radioactivity failed.

The present invention limits the content of sulfoaluminate cement clinker to 5% to 10%. During the hydrolysis process, sulfoaluminate cement clinker can provide aluminate ions, calcium ions and sulfate ions, which can be combined with sulfuric acid in lithium slag. Calcium and calcium hydroxide in cement hydration form ettringite to achieve the effect of compensating shrinkage.

The content of the superplasticizer of the present invention in the composite mineral admixture is 0.5-1.0‰, which can effectively improve the fluidity of the composite mineral admixture and ensure its fluidity ratio ≥ 105%. On the other hand, superplasticizers have obvious surfactant properties, and after being added, they can reduce the surface tension of the aqueous solution in the pores of the cementitious material slurry, and reduce the shrinkage caused by capillary action, so it is beneficial to the improvement of the shrinkage performance of the system.

The content of the early-strength grinding aid of the present invention in the composite mineral admixture is 0.3-0.5‰, which can effectively improve the grinding efficiency of various raw materials and save production costs.

The present invention also provides a preparation method of a high-activity, low-shrinkage composite mineral admixture, comprising the following steps:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorous slag and 0.3~0.5‰ early-strength grinding aid with vertical grinding equipment until the specific surface area is 450~600m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.3-0.5‰ early-strength grinding aid until the specific surface area is 450-650m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 350~600m ² /kg;

S5: Weigh the processed powder and other raw materials of S2~S4 according to the following proportions, lithium slag 15%~25%, granulated electric furnace phosphorus slag 30%~50%, vanadium iron slag 10%~20%, Nickel slag 10%~15%, sulfoaluminate cement clinker 5%~10%, superplasticizer 0.5~1.0‰;

S6: Dry-mix the weighed raw materials evenly to obtain a high-activity, low-shrinkage composite mineral admixture.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. A high-activity, low-shrinkage composite mineral admixture and its preparation method provided by the embodiment of the present invention, using lithium slag, ferrovanadium slag, granulated electric furnace phosphorus slag, nickel slag and sulphoaluminate cement clinker to compound As a mineral admixture, it gives full play to the synergistic and complementary effects of different types of slag and raw materials, and realizes the anti-shrinkage ability of the composite mineral admixture from the early stage to the later stage;

2. A high-activity, low-shrinkage composite mineral admixture and its preparation method provided by the embodiment of the present invention, the prepared mineral composite mineral admixture has an activity index ≥ 70% at 7d, an activity index ≥ 90% at 28d, and a fluidity ratio of ≥100%, the radioactivity is qualified, which solves the problem that a single industrial slag powder cannot meet the application requirements.

Implementation

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail in conjunction with the following examples. The schematic embodiments of the present invention and their descriptions are only used to explain the present invention, and are not intended as a guideline for the present invention. limit.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one of ordinary skill in the art that these specific details need not be employed to practice the present invention. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present invention.

Throughout this specification, reference to "one embodiment," "an embodiment," "an example," or "example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in the present invention. In at least one embodiment. Thus, appearances of the phrases "one embodiment," "an embodiment," "an example," or "example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, particular features, structures or characteristics may be combined in any suitable combination and/or subcombination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

Example 1

An embodiment of the present invention provides a method for preparing a high-activity, low-shrinkage composite mineral admixture, comprising the following steps:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 500m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 600m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 400m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions, lithium slag 20%, granulated electric furnace phosphorus slag 43%, vanadium iron slag 17%, nickel slag 12%, sulfoaluminate Cement clinker 8%, superplasticizer 0.60‰;

S6: Dry mix the weighed raw materials evenly.

According to "Composite Admixtures for Concrete" JG/T 486-2015 Appendix A, detect according to the mass ratio of 7:3 between cement and the high-performance composite mineral admixture of this embodiment, and test the 7d activity index of the composite mineral admixture , 28d activity index and mobility ratio.

According to GB/T 17671-2021, the mass ratio of cement and high-performance composite mineral admixture of this embodiment is 7:3 for molding, and the dry shrinkage mortar test piece is molded with a 40mm×40mm×160mm triple steel mold. There are 3 blind holes of 6mm in each end plate. Before forming, place a round-headed copper rod probe with a length of 2.5cm and a diameter of 6mm. After forming, the surface is covered with a layer of plastic wrap and placed in a standard curing room for curing temperature (20±3 ) ℃ relative humidity above 90% curing 1d demoulding; use a screw micrometer to measure the initial value of the length of the specimen (unit: mm accurate to 0∙001mm); move into a constant temperature and humidity room (curing temperature (20±2) ℃ relative Humidity 60% ± 5%) respectively test the length of the specimen at the initial stage of curing and 28d, and test its shrinkage.

Judge the radioactive index of this embodiment according to "Limits of Radionuclides in Building Materials" GB 6566-2010.

Example 2

An embodiment of the present invention provides a method for preparing a high-activity, low-shrinkage composite mineral admixture, comprising the following steps:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 500m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 600m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 400m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions, lithium slag 20%, granulated electric furnace phosphorus slag 47%, vanadium iron slag 15%, nickel slag 10%, sulfoaluminate Cement clinker 8%, superplasticizer 0.60‰;

S6: Dry mix the weighed raw materials evenly.

The high-performance composite mineral admixture of this example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Example 3

An embodiment of the present invention provides a method for preparing a high-activity, low-shrinkage composite mineral admixture, comprising the following steps:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 500m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 600m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 400m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions, lithium slag 18%, granulated electric furnace phosphorus slag 44%, vanadium iron slag 18%, nickel slag 13%, sulfoaluminate Cement clinker 7%, superplasticizer 0.60‰;

S6: Dry mix the weighed raw materials evenly.

The high-performance composite mineral admixture of this example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 1

For blank comparison, cement is used alone without mixing the mineral admixture according to the present invention, and the detection method is the same as in Example 1.

Comparative example 2

This comparative example adopts granulated electric furnace phosphorus slag powder to prepare mineral admixture, and the steps are as follows:

S1: Dry the granulated electric furnace phosphorous slag until the moisture content is ≤1%;

S2: Mix the dried granulated electric furnace phosphorus slag with 0.4‰ early-strength grinding aid, and use a ball mill to grind to a specific surface area of 500m ² /kg;

The maximum size of the granulated electric furnace phosphorous slag is no more than 50 mm and no more than 5% of the particles are larger than 10 mm. The chemical composition P ₂ O ₅ is 1.8%, the mass coefficient K is 1.3, and the glass phase content is 87%. The internal illumination index I _Ra is 1.1, and the external illumination index I _γ is 1.0.

The mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 3

This comparative example adopts lithium slag powder to prepare mineral admixture, and the steps are as follows:

S1: Dry the lithium slag until the moisture content is ≤1%;

S2: Grinding the dried lithium slag to a specific surface area of 550m ² /kg to form a mineral admixture.

The lithium slag is a by-product of lithium smelting by the sulfuric acid method, the content of SiO ₂ +Al ₂ O ₃ is 70%, the content of SO ₃ is 6.5%, the water demand ratio is 113%, the internal illumination index I _Ra is 0.3, and the external According to the exponent I _γ is 0.3.

The mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 4

This comparative example adopts ferrovanadium slag to prepare mineral admixture, and the steps are as follows:

S1: Dry the ferrovanadium slag until the moisture content is ≤1%;

S2: Mix the dried ferrovanadium slag with 0.4‰ early-strength grinding aid, and grind to a specific surface area of 650m ² /kg to form a mineral admixture.

The vanadium-iron slag is the vanadium-iron slag produced by-product of vanadium-titanium alloy by the aluminothermic method, its calcium oxide content is 57%, magnesium oxide content is 9.7%, loss on ignition is 2.2%, internal illumination index I _Ra is 0.2, external illumination The index I _γ is 0.2.

The mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 5

This comparative example adopts nickel slag to prepare mineral admixture, and the steps are as follows:

S1: Dry the nickel slag until the moisture content is ≤1%;

S2: Mix the dried nickel slag with 0.4‰ early-strength grinding aid, and grind to a specific surface area of 600m ² /kg to form a mineral admixture.

The mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 6

This comparative example adopts technique on the basis of embodiment 1 and is not in the raw material preparation composite mineral admixture within the scope of the present invention, and the steps are as follows:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 300m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 400m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 300m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions, lithium slag 20%, granulated electric furnace phosphorus slag 43%, vanadium iron slag 17%, nickel slag 12%, sulfoaluminate Cement clinker 8%, superplasticizer 0.60‰;

S6: Dry mix the weighed raw materials evenly.

The preparation method and detection method of the composite mineral admixture of this comparative example are all the same as in Example 1.

Comparative example 7

This comparative example adopts the raw material that proportioning is not within the scope of the present invention on the basis of embodiment 1 to prepare composite mineral admixture, and the steps are as follows:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 500m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 600m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 400m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions: 20% lithium slag, 70% granulated electric furnace phosphorous slag, 5% ferrovanadium slag, 5% nickel slag, sulfoaluminate Cement clinker 0%, superplasticizer 0.60‰;

S6: Dry mix the weighed raw materials evenly.

The composite mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Comparative example 8

This comparative example adopts the raw material that proportioning is not within the scope of the present invention on the basis of embodiment 1 to prepare composite mineral admixture, and the steps are as follows:

S1: Dry lithium slag, vanadium-iron slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%;

S2: Grind the dried granulated electric furnace phosphorus slag and 0.4‰ early-strength grinding aid with vertical grinding equipment to a specific surface area of 500m ² /kg;

S3: Mix and grind the dried lithium slag powder, vanadium iron slag, nickel slag and 0.4‰ early-strength grinding aid until the specific surface area is 600m ² /kg;

S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 400m ² /kg;

S5: Weigh the processed powder of S2~S4 and other raw materials according to the following proportions, lithium slag 50%, granulated electric furnace phosphorus slag 20%, vanadium iron slag 20%, nickel slag 10%, sulfoaluminate Cement clinker 0%;

S6: Dry mix the weighed raw materials evenly.

The composite mineral admixture of this comparative example is mixed with cement for performance testing, and the testing method is the same as that of Example 1.

Table 1 The properties of the mortar test blocks obtained in the examples and comparative examples

serial number 7d activity index/% 28d activity index/% Fluidity ratio/% radioactivity <![CDATA[28d shrinkage rate/10^-6]]> Example 1 76 92 102 qualified 95 Example 2 78 94 102 qualified 93 Example 3 75 91 103 qualified 82 Comparative example 1 -- -- -- qualified 406 Comparative example 2 72 94 101 unqualified 275 Comparative example 3 76 106 88 qualified 251 Comparative example 4 69 81 96 qualified twenty three Comparative example 5 64 77 97 qualified 42 Comparative example 6 66 85 98 qualified 164 Comparative example 7 74 97 102 qualified 233 Comparative example 8 71 94 85 qualified 115

The test results of Examples and Comparative Examples are shown in Table 1. As can be seen from Table 1, by comparing Example 1 with Comparative Examples 2 to 4, it can be seen that single phosphorus slag powder, lithium slag powder, vanadium-iron slag powder, and nickel slag powder have low activity index, poor fluidity, and unqualified radioactivity. one or more questions.

By comparing Example 1 and Comparative Example 5, it can be seen that the comprehensive performance of the composite mineral admixture prepared not according to the requirements of the present invention is poor.

By comparing Example 1 with Comparative Examples 6-7, it can be seen that the composite mineral admixture not formulated according to the ratio of the present invention has the problems of low activity index and low fluidity.

In summary, the mineral composite mineral admixture prepared according to the present invention can meet the requirements of 7d activity index ≥ 70%, 28d activity index ≥ 90%, fluidity ratio ≥ 95%, radioactive requirements, and its 28d shrinkage rate Compared with the sample of Comparative Example 1 (no mineral admixture), the reduction is more than 50%, which can effectively reduce the shrinkage of the matrix material and help improve the shrinkage and cracking resistance of the cement-based material.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, within the spirit and principles of the present invention, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims (2)

1. A high activity, low shrinkage composite mineral admixture, is characterized in that, comprises the raw material component of following percentage by weight: lithium slag 15%～25%, granulated electric furnace phosphorous slag 30%～50%, vanadinite Slag 10%~20%, nickel slag 10%~15%, sulphoaluminate cement clinker 5%~10%, superplasticizer 0.5~1.0‰, early strength grinding aid 0.3~0.5‰; The lithium slag is a by-product of lithium smelting by the sulfuric acid method, and its SiO ₂ +Al ₂ O ₃ content is ≥ 65%, SO ₃ content is ≥ 5% and ≤ 10.0%, the water demand ratio is ≤ 115%, and the internal illumination index is I _Ra ≤0.6, external illumination index I _γ ≤0.6; The chemical composition P ₂ O ₅ in the granulated electric furnace phosphorus slag is ≤3.5%, the mass coefficient K≥1.0, the glass phase content in the granulated electric furnace phosphorus slag is ≥80%, and the internal illumination index I of the granulated electric furnace phosphorus slag is _Ra ≤1.5, external illumination index I _γ ≤1.5; The nickel slag is the waste slag discharged from the production of non-ferrous metal nickel, its magnesium oxide content is ≥ 30% and ≤ 50%, the internal illumination index I _Ra ≤ 0.6, and the external illumination index I _γ ≤ 0.6; The ferrovanadium slag is ferrovanadium slag, a by-product of ferrovanadium alloy production by the thermite method, with a calcium oxide content of ≥50%, a magnesium oxide content of 5%~15.0%, an internal illumination index I _Ra ≤0.6, and an external illumination index I _γ ≤ 0.6. 2. the preparation method of a kind of high activity, low shrinkage composite mineral admixture described in claim 1, is characterized in that, comprises the steps: S1: Dry lithium slag, ferrovanadium slag, nickel slag, and granulated electric furnace phosphorus slag until the moisture content is ≤1%; S2: Grind the dried granulated electric furnace phosphorous slag and 0.3~0.5‰ early-strength grinding aid with vertical grinding equipment until the specific surface area is 450~600m ² /kg; S3: Mix and grind the dried lithium slag, ferrovanadium slag, nickel slag and 0.3~0.5‰ early-strength grinding aid until the specific surface area is 450~650m ² /kg; S4: Grinding the sulphoaluminate cement clinker to a specific surface area of 350~600m ² /kg; S5: Weigh the processed powder of S2~S4 and other raw materials according to the following weight percentages, lithium slag 15%~25%, granulated electric furnace phosphorus slag 30%~50%, vanadium iron slag 10%~20% , nickel slag 10%~15%, sulphoaluminate cement clinker 5%~10%, superplasticizer 0.5~1.0‰; S6: Dry-mix the weighed raw materials evenly to obtain a high-activity, low-shrinkage composite mineral admixture.