CN115159875B

CN115159875B - Method for preparing composite cementing material by utilizing tail slag after multi-element solid waste iron extraction

Info

Publication number: CN115159875B
Application number: CN202210718738.6A
Authority: CN
Inventors: 王长龙; 刘枫; 荆牮霖; 张晓刚; 李彦苍; 吴平川; 马锦涛; 齐洋; 平浩岩; 张凯帆; 陈敬亮; 李鑫; 张鸿泽; 杨丰豪; 樊英杰
Original assignee: Tangshan Zhuoneng Building Materials Technology Co ltd; Tianjin Tianxing Fuda Technology Co ltd; Hebei University of Engineering; China Railway Construction Group Architecture Development Co Ltd
Current assignee: Tangshan Zhuoneng Building Materials Technology Co ltd; Tianjin Tianxing Fuda Technology Co ltd; Hebei University of Engineering; China Railway Construction Group Architecture Development Co Ltd
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2023-07-21
Anticipated expiration: 2042-06-23
Also published as: CN115159875A

Abstract

The invention provides a method for preparing a composite cementing material by utilizing tailings after multi-element solid waste iron extraction, which comprises the following steps: stainless steel slag pretreatment, red mud pretreatment, strong magnetic separation, calcium raw material pretreatment, carbonaceous raw material pretreatment, siliceous raw material pretreatment, aluminum raw material pretreatment, compression molding, high-temperature calcination, wet mineral separation, powder 3 pretreatment, composite gypsum pretreatment, cement clinker pretreatment, preparation of a water reducer and preparation of a composite cementing material. The invention solves the problems of harmless, reduction and recycling of industrial solid waste, agricultural solid waste and building solid waste, and promotes the cooperative utilization of multiple solid wastes and environmental protection.

Description

Method for preparing composite cementing material by utilizing tail slag after multi-element solid waste iron extraction

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to a method for preparing a composite cementing material by utilizing tailings after multi-element solid waste iron extraction.

Background

Red mud is an alkaline extract produced in the process of producing alumina from bauxite, and contains a large amount of Fe ₂ O ₃ The red mud is red brown, has high water content and belongs to harmful residues with strong alkalinity, and the output of the red mud is not nearly the same due to the difference of ore grade, technical level and production method, and the red mud is discharged by about 1.0-1.8 t per 1t of alumina produced. According to statistics, the annual output of red mud in China reaches over 4000 ten thousand tons. The accumulation of a large amount of red mud not only occupies a large amount of land, but also is opposite to the ring Serious damage is caused to the environment, and the problems of surface and underground water pollution, soil alkalization and the like are caused. As secondary resources, the comprehensive utilization of the red mud mainly comprises three aspects, namely, extraction and recovery of valuable metals; secondly, preparing building materials; thirdly, preparing the adsorption material. Although red mud has been widely used in these fields, the comprehensive utilization rate of red mud in China is quite low, and is less than 20% of the output.

The coal gasification residue is coal particles in the gasification furnace are rapidly decomposed at high temperature in the coal gasification process, and the graphitization degree of carbon is deepened continuously along with the continuous volatilization of volatile matters to generate coal char; then gasifying agents such as oxygen, steam and the like are diffused into the particles to carry out gasification reaction, so as to generate synthetic gas; when the coal coke particles reach the critical state of crushing, the coal coke particles start to be crushed, the components such as mineral substances in coal are converted into slag through homogeneous phase and heterogeneous phase reactions, a part of slag is attached to the gasifier wall, flows into the gasifier bottom along the wall in a molten state, and is solidified into coarse slag through chilling, and the grain size is larger; and the other part is carried out by the air flow, and enters a subsequent purification process along with the synthesis gas to form fine slag with smaller particles, and finally the coarse slag and the fine slag are discharged by the gasification system.

Stainless steel slag is a byproduct generated during the production of stainless steel, and is produced at a high temperature, and is cooled to form tailings, wherein about 270kg of tailings are produced per 1t of stainless steel produced. Stainless steel slag is largely divided into electric furnace slag (ElectricArc Furnace, EAF) and argon oxygen decarburization slag (Argon Oxygen Decarburization, AOD). The EAF slag is generally black (containing iron oxide), has an alkalinity of about 1.6, belongs to low-alkalinity slag, has larger particles and stable property, and is cooled after high temperature generation to be in a block shape. The AOD slag has less metal content, white color and high alkalinity, generally reaches more than 2.0, is easy to crush after being cooled at high temperature, and has less particles. Stainless steel slag, which is industrial waste slag discharged in the ferrous metallurgy process, has a partial mineral composition similar to cement, and can be considered as an auxiliary cementing material. Accordingly, some researchers have begun exploring the use of stainless steel slag to make cementitious materials instead of, or in part instead of, cement.

How to effectively utilize the wastes such as stainless steel slag, red mud and the like, changes waste into valuable, greatly reduces environmental pollution, and simultaneously realizes great economic benefit and social benefit, so the technical problem is needed to be solved.

Disclosure of Invention

The invention provides a method for preparing a composite cementing material by utilizing tailings after iron extraction from multiple solid wastes, which not only can effectively utilize valuable metals in metallurgical solid wastes (stainless steel slag and red mud), but also can realize the cooperative utilization of industrial solid wastes, ocean solid wastes and agricultural solid wastes, thereby realizing the purposes of energy conservation and environmental protection, reducing environmental protection pressure of mining areas, construction sites and agricultural production, simultaneously providing a new direction for the resource application of the solid wastes, promoting the building production to go forward towards the targets of carbon peak and carbon neutralization, and realizing the synergistic efficient development of building industrialization and solid waste recycling.

The invention discloses a method for preparing a composite cementing material by utilizing tailings after multi-element solid waste iron extraction, which comprises the following steps:

s1, stainless steel slag pretreatment: the original stainless steel slag with the particle size of 10 to 25mm is placed into a carbonization box to be carbonized for 72 to 120 hours, the carbonized stainless steel slag is placed into a drying box with the temperature of 105 ℃ to be dried by blast until the weight is constant, then the stainless steel slag is crushed into particles with the particle size of 1 to 3mm by a jaw crusher, and then the particles are placed into a ball mill to be ground into the specific surface area of 200 to 300m ² /kg；

S2, preprocessing red mud: stacking and airing the red mud to make the water content of the red mud be less than 10-15%, drying the red mud for 12 hours at 105 ℃, taking out the red mud, cooling the red mud in dry air, dispersing the red mud by adopting a planetary ball mill to make the specific surface area of the material reach 400-550 m ² /kg；

S3, strong magnetic separation: uniformly mixing the pretreated stainless steel slag and red mud according to the proportion of 2-4:1, putting the mixture into a planetary mill for uniform mixing, and putting the mixed powder into a strong magnetic separator for magnetic separation to obtain metal fine powder 1 and powder 1;

s4, pretreatment of a calcareous raw material:

(1) Pretreatment of silicon-calcium slag: firstly, screening the calcium silicate slag, removing organic impurities in the calcium silicate slag, and then placing the calcium silicate slag in an electrothermal drying oven at 105 ℃ for drying for 12 hours for later use;

(2) Pretreatment of phosphate tailings: placing the phosphate tailings into a drying box at 105 ℃ for forced air drying until the water content is less than 1% for later use;

(3) The dried phosphate tailings and the calcium silicate slag are put into a planetary mill according to the proportion of 1:1-2 to be uniformly mixed, and then are put into a muffle furnace to be calcined, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 750-900 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the temperature is kept for 50-100 min; cooling to room temperature by air blast after calcining, and taking out a sample; then the powder material cooled to room temperature is put into a ball mill, and ground to the specific surface area of 400-600 m ² And (3) kg, obtaining a calcareous raw material for standby;

s5, pretreatment of a carbonaceous raw material:

(1) Waste fruit tree branch treatment: peeling waste fruit tree branches with the diameter of 5-35 mm, naturally drying the fruit tree branches outdoors for 1-3 months to reduce the water content to be lower than 10%, putting the crushed fruit tree branches into a 70 ℃ drying box for forced air drying to constant weight, and crushing the dried fruit tree branches to the particle size of 1-2 mm by adopting a crusher;

(2) Treating waste fir branches: peeling the surface of the waste fir tree branch with the diameter of 5-35 mm, naturally drying the waste fir tree branch outdoors for 1-3 months to reduce the water content to be lower than 10%, putting the crushed broken tree branch into a 70 ℃ drying box for forced air drying to constant weight, and crushing the dried tree branch into the grain size of 1-3 mm by adopting a vertical tree branch pulverizer;

(3) Uniformly mixing the pretreated fruit tree branches and fir tree branch particles according to the mass ratio of 2-3:1-4 to obtain a carbonaceous raw material for later use;

s6, pretreatment of siliceous raw materials: crushing the photovoltaic panel in a jaw crusher to obtain particles with the particle size of 10-20 mm, then drying the particles in an electrothermal drying oven, calcining the dried particles in a muffle furnace at 900-1300 ℃, and preserving the temperature for 50-100 min; cooling to room temperature by air blast after calcining, and taking out a sample; grinding again to a specific surface area of 400-600 m ² Per kg, obtaining siliceous raw materials for later use；

S7, pretreatment of aluminum raw materials:

(1) Pretreatment of coal gasification residues: crushing coal gasification residues into particles with the diameter of 1-3 mm by a jaw crusher, and drying the crushed coal gasification residue particles at 105 ℃ for 12 hours for later use;

(2) Pretreatment of aluminum ash: firstly, screening aluminum ash, removing organic impurities in the aluminum ash, and then placing the aluminum ash in an electrothermal drying oven at 105 ℃ for drying for 12 hours;

(3) Mixing the pretreated coal gasification residues and aluminum ash residues according to the mass ratio of 1:1-2, and then putting the mixture into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 300-400 m ² Kg, obtaining an aluminum raw material;

s8, press forming: the method comprises the steps of (1) mixing 30-40% by weight of a calcium material in powder 1, 14-21% by weight of a carbonaceous material in S4, 10-15% by weight of an aluminum material in S7 and 8-13% by weight of a siliceous material in S5, and uniformly putting the powder into a planetary mill; adding 8-11% of water into the obtained dry material mixture, then placing the mixture into a mould, and pressing the mixture into pellets with the size of phi 30mm multiplied by 20mm by a hydraulic press; placing the pellets into an electric heating drying box at the temperature of 100 ℃ for constant temperature drying for 20-40 min;

s9, high-temperature calcination: placing the pellets formed by compression in the step S8 into a covered corundum crucible, and placing the corundum crucible into a muffle furnace for high-temperature calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 800 ℃, wherein the temperature raising rate is 0.5 ℃/min, and then preserving the heat for 20min; then the temperature is increased from 800 ℃ to 1200 ℃ to 1300 ℃ which is the required temperature, the heating rate is 3.5 ℃/min, and then the temperature is kept for 30 to 120min; cooling to 1000-1100 deg.c after calcining, taking out sample, quenching the sample to room temperature;

S10, wet ore dressing: crushing the high-temperature calcined product obtained in the step S9 to 1-3 mm particles by using a jaw crusher, then performing wet grinding by using an RK/BK three-roller four-drum rod mill, performing wet separation in a weak magnetic field magnetic separation tube to obtain metal fine powder 2 and tailings modified powder, drying to obtain the metal fine powder 2 and tailings modified dry powder, and then placing the tailings modified dry powder into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 500-700 m ² Per kg, to obtain a powderMaterial 2;

s11, pretreatment of powder 3:

(1) Dicyandiamide waste residue pretreatment: placing the dicyandiamide waste residue in an electrothermal drying oven at 105 ℃ for drying for 12 hours for standby;

(2) Pretreatment of waste stone powder: placing the waste stone powder into a drying box at 105 ℃ for forced air drying until the water content is less than 1%;

(3) The dried dicyandiamide waste residue and waste stone powder are put into a planetary mill according to the mass ratio of 2:1, and are evenly mixed, and then are put into a muffle furnace for calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 750-900 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the temperature is kept for 50-100 min; taking out the sample after the calcination is completed and the air blast cooling is carried out to room temperature, putting the powder cooled to the room temperature into a ball mill, and grinding the powder to the specific surface area of 400-600 m ² Kg, obtaining powder 3;

s12, pretreatment of composite gypsum: respectively scattering the fluorogypsum and the desulfurized gypsum, then placing the fluorogypsum and the desulfurized gypsum into a blast drying oven at 50-70 ℃ for drying for 48-60 hours, uniformly mixing the dried fluorogypsum and desulfurized gypsum according to the mass ratio of 1:1-2, and then placing the fluorogypsum and desulfurized gypsum into a cement ball mill at the rotating speed of 48r/min for grinding until the specific surface area is 300-400 m ² Kg, obtaining powder 4;

s13, cement clinker pretreatment: placing the cement clinker into a jaw crusher, crushing the cement clinker into particles with the particle size of 1-3 mm, drying the crushed cement clinker for 12 hours at the temperature of 105 ℃, and then placing the cement clinker into a cement ball mill with the rotating speed of 42r/min for grinding until the specific surface area is 300-400 m ² /kg；

S14, preparing a water reducer: adding a isopentenyl alcohol polyoxyethylene ether macromer (IPEG) with the monomer mole number of 2-4 mol into a reaction kettle, heating to 60-68 ℃ and starting stirring; adding Acrylic Acid (AA) with the mass ratio of IPEG of 4-30% and mercaptopropionic acid with the mass ratio of 0.7-1% into a dripping tank, and uniformly stirring and mixing to obtain dripping liquid; adding sodium persulfate with the mass ratio of 1-1.5% of IPEG into a reaction kettle after the IPEG macromonomer is completely melted, dropwise adding the dropwise adding liquid through a constant flow pump after the sodium persulfate is dissolved, wherein the total dropwise adding time is 4.0h, and adding sodium persulfate respectively in 2.0h and 3.0h, wherein the mass of the sodium persulfate added each time is 0.2% of that of the IPEG; after the dripping is finished, carrying out heat preservation and aging reaction for 1-1.5 hours, naturally cooling and hardening, and then crushing and grinding to obtain the solid polycarboxylate superplasticizer;

S15, preparing a composite cementing material: mixing powder 2 obtained in S10, powder 3 in S11, powder 4 in S12 and cement clinker in S13 according to the mass ratio of 55-75% to 10-15% to 5-15% to obtain a cementing material, adding water reducer in S14 according to the mass ratio of 0.1-0.2% of the cementing material, and adding Ca (NO) of 0.1-0.3% of the mass ratio of the cementing material ₃ ) ₂ And finally, carrying out ball milling and mixing on the additive to obtain the composite cementing material.

Optionally, the carbonization conditions in the step S1 are: CO ₂ The concentration is 15-25%, the temperature is 20+ -1 ℃, and the humidity is 85% + -1.

Optionally, the magnetic separation strength of the step S3 magnetic separator is 1-3T, and the rotating speed of the magnetic separator is 10-30 r/min.

Optionally, in the step S8, the pressure of the press molding is 15 to 25MPa.

Optionally, in the step S10, the wet grinding is performed until the diameter of the wet grinding is-0.074 mm and the diameter of the wet grinding is more than 90-95%, and the magnetic separation setting strength of the low-intensity magnetic separation tube is 1600-1800 Oe.

Optionally, the main chemical components and contents of the stainless steel slag in the step S1 are as follows: al (Al) ₂ O ₃ 5～10％，SiO ₂ 16～20％，CaO 9～48％，MgO2～8％，Fe ₂ O ₃ 27％～31％，MnO 1～6％，Cr ₂ O ₃ 4-10%; the main chemical composition of the red mud in the step S2 is as follows: siO (SiO) ₂ 10～25％，Al ₂ O ₃ 20～30％，Fe ₂ O ₃ 30～40％，MgO 0.1～2％，CaO 5～15％，K ₂ O 0.01～1％，Na ₂ O 1～10％，TiO ₂ 1-8% and loss on ignition 9-15%.

Optionally, in the step S4, the main mineral components of the phosphate tailings are dolomite, quartz, fluorapatite and a small amount of calcite, and the main chemical components and the content thereof are as follows: siO (SiO) ₂ 2～5％，Al ₂ O ₃ 0.2～1％，Fe ₂ O ₃ 1～6％，MgO 10～18％，CaO 25～35％，Na ₂ O 0.01～1％，K ₂ O 0.01～1％，CO ₂ 25～40％，MnO 0.1～1％，P ₂ O ₅ 1 to 8 percent; the main chemical composition of the silicon-calcium slag is as follows: siO (SiO) ₂ 20～30％，Al ₂ O ₃ 5～15％，Fe ₂ O ₃ 2-3 percent of MgO, 2-3 percent of MgO and 40-55 percent of CaO; the chemical composition and industrial analysis of the waste fruit tree branches in the step S5 are as follows: 35-45% of C, 5-10% of H, 45-55% of O, 0.1-1% of N, 0.1-2% of S, 5-12% of water, 1-2% of ash, 75-90% of volatile matters and 5-8% of fixed carbon; the chemical composition and industrial analysis of the fir branches are as follows: 40-55% of C, 5-8% of H, 43-52% of O, 0.8-1.2% of N, 0.4-0.9% of S, 16-21% of water, 3-6% of ash, 65-78% of volatile matter and 27-36% of fixed carbon.

Optionally, the chemical components of the waste photovoltaic panel in the step S6 are as follows in percentage by mass: siO (SiO) ₂ 65～75％，NaCl 20～40％，CaCl ₂ 0.01 to 3.5 percent, the loss on ignition is 0.01 to 4 percent, and the other is 0.01 to 2.5 percent; the main chemical composition of the coal gasification residue in the step S7 is as follows: siO (SiO) ₂ 35～65％，Al ₂ O ₃ 12～20％，Fe ₂ O ₃ 15～20％，MgO 3～7％，CaO 5～18％，K ₂ O 2～3％，Na ₂ O 2～3％，SO ₃ 0.1～1.5％，P ₂ O ₅ 0.01 to 1 percent, tiO20.1 to 2 percent, and loss on ignition 15 to 40 percent; in the step S7, the aluminum ash is fine ash after separating out metal aluminum, and the main chemical components and contents are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 45～75％，AlN 20～25％，AlCl ₃ 2～6％，AlF ₃ 1 to 6 percent and 8 to 30 percent of loss on ignition.

Optionally, in the step S11, the dry basis granularity of the dicyandiamide waste residue is 0.01-0.1 mm, the main mineral composition is calcite, and the main chemical components and the content are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 1～8％，CaO 45～65％，Fe ₂ O ₃ 1～8％，MgO 0.01～4％，K ₂ O+Na ₂ O 0.01～3％，C 5～25％20-35% of loss on ignition; the waste stone powder in the step S11 is waste generated in the process of preparing the machine-made sand, and the main chemical components and the content are as follows: siO (SiO) ₂ 5～30％，Al ₂ O ₃ 1～8％，CaO 45～65％，Fe ₂ O ₃ 1～6％，MgO 3～8％，K ₂ O+Na ₂ 0.01 to 3 percent of O and 20 to 35 percent of loss on ignition; optionally, the effective CaO content in the powder 3 prepared in the step S11 is 68-72%, the MgO content is less than 3%, the digestion temperature is 66-70 ℃, the digestion time is 10-14 min, the screen residue of the 0.08 square hole screen is 9-13%, and the powder meets the requirements of ASTM C5-2010 Standard Specification of quicklime for construction.

Optionally, the main chemical components and contents of the fluorogypsum in the step S12 are as follows: caO 35-40%, siO ₂ 0.2～6％，Al ₂ O ₃ 0.2～4％，MgO 0.1～1％，SO ₃ 35～50％，CaF ₂ 2-8%; optionally, the main chemical components and contents of the desulfurized gypsum in the step S12 are as follows: SO (SO) ₃ 30～55％，CaO 20～45％，SiO ₂ 2～4％，P ₂ O ₅ 1～3.5％，MgO 0.01～2.5％，Na ₂ O 0.01～1.5％，Fe ₂ O ₃ 0.01～6％，K ₂ 0.01 to 1.5 percent of O, 15 to 30 percent of loss on ignition and 0.01 to 1 percent of other components.

The beneficial effects of the invention are as follows:

(1) The composite cementing material is prepared by utilizing red mud, stainless steel slag, silicon-calcium slag, phosphate tailings, aluminum ash, coal gasification residues, waste photovoltaic plates, dicyandiamide waste residues, fluorogypsum, desulfurized gypsum, waste fir branches, waste fruit branches and waste stone powder in a synergistic manner, solves the problems of harmless, reduction and recycling of industrial solid waste, agricultural solid waste and building solid waste, and promotes the synergistic utilization of multiple solid wastes and environmental protection.

(2) Compared with the existing composite cementing material production, the invention is characterized in that the raw materials comprise red mud, stainless steel slag, calcium silicate slag, phosphate tailings, waste fruit branches, waste fir branches, aluminum ash, coal gasification residues, dicyandiamide waste residues, fluorgypsum and desulfurized gypsum, and the utilization rate of waste reaches 100%. The radioactivity of the cementing material accords with the specification of GB6566, 8 heavy metal indexes of the cementing material are lower than the standard limit value in GB/T14848-2017 groundwater quality standard, and the cementing material is more green, low-carbon and environment-friendly, and meets the requirement of 'double carbon' of building material products advocated by China.

(3) The invention is based on the thought of treating waste by waste, so that various wastes are utilized with high value. The method comprises the steps of firstly separating iron in the strong magnetic part in the ground stainless steel slag and red mud by using strong magnetic separation, then using waste fruit branches and waste fir branches as reducing agents, using silicon-calcium slag and phosphate tailings as additives, recovering other valuable metal components in tailings by high-temperature calcination, water quenching and wet grinding magnetic separation, and using the residual waste tailings to prepare the composite cementing material, so that the high added value utilization of waste resources is realized.

(4) The grade of Fe in the recovered high-intensity magnetic separation recovered metal fine selection powder can reach 65-72%, and the iron-making requirement of the iron and steel industry is met. The grade of Fe in the metal fine powder of the product after high-temperature calcination can reach 91-94%, and the recovery rate of Fe is 90-95%.

(5) According to the invention, the waste photovoltaic plate, coal gasification residue and aluminum ash are added into the powder material calcined at high temperature, so that Si and Al elements which are lack in high-temperature modification of stainless steel slag and red mud are supplemented, and target mineral C in the powder material is effectively regulated and controlled ₃ S、C ₂ S、C ₃ A is generated to regulate and control C in powder ₄ And (3) generating AF. The activity indexes of 7d and 28d of tailings produced after calcination and wet mineral separation respectively reach 87-95% and 97-101%, the national standard requirement of GB/T18046-2017 'granulated blast furnace slag powder for cement, mortar and concrete' is met, and the content of f-CaO in the tailings powder is less than 2%.

(6) The invention utilizes the characteristics of various solid wastes and fully exerts the synergistic effect among multiple solid wastes. The dicyandiamide waste residue and the waste stone powder are mixed and calcined, so that effective CaO is provided for a composite cementing material system, and meanwhile, the activity of the powder 2 is chemically excited; caSO in powder 4 ₄ ·2H ₂ The O plays a role in retarding, and prevents the raw materials from being rapidly hydrated.

Drawings

FIG. 1 shows a process for preparing the powder 1 according to the invention.

FIG. 2 shows a process for preparing the powder 2 according to the invention.

FIG. 3 shows a process for preparing the powder 3 according to the invention.

FIG. 4 shows a process for preparing the powder 4 according to the invention.

FIG. 5 is a process for preparing the composite cementitious material of the present invention.

FIG. 6 shows XRD patterns of raw materials (a) -stainless steel slag, (b) -red mud, (c) -coal gasification residues, (d) -calcium silicate slag, (e) -phosphate tailings and (f) -dicyandiamide waste residues; (g) -spent stone powder, (h) -desulphurized gypsum, (i) -cement clinker.

FIG. 7 is a graph of the thermal analysis of hydration (a) -thermal heat of hydration heat release rate for the composite cement of example 2; (b) -total heat of hydration.

FIG. 8 is an XRD pattern for neat cement slurries (a) -3d, 7d, 28d for example 2, and (b) -28d age neat cement slurries for the composite cement slurries.

FIG. 9 is a FT-IR spectrum of neat composite cement samples of different ages of example 2.

FIG. 10 is a TG-DSC spectrum of sample hydration 28d of the composite cement of example 2, (a) 50-500℃and (b) 500-1000 ℃.

FIG. 11 is a partial enlarged view of SEM morphologies (a) -3d, (b) -3d, (c) -7d, (d) -7d, and (e) -28d, and (f) -28d for different ages of a cement paste sample of example 2.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the invention, fall within the scope of protection of the invention.

Example 1

A method for preparing a composite cementing material by utilizing tailings after multi-element solid waste iron extraction comprises the following steps:

s1, stainless steel slag pretreatment: placing 10-25 mm granular undisturbed stainless steel slag into a carbonization box for carbonization 72h, then placing the carbonized stainless steel slag into a drying box at 105 ℃ for forced air drying to constant weight, then crushing the stainless steel slag into particles with the particle size of 1-3 mm by adopting a jaw crusher, and then placing the particles into a ball mill for grinding until the specific surface area is 300m ² /kg；

S2, preprocessing red mud: stacking and airing the red mud to make the water content of the red mud be less than 10-15%, drying the red mud for 12 hours at 105 ℃, taking out the red mud, cooling the red mud in dry air, dispersing the red mud by adopting a planetary ball mill to make the specific surface area of the material reach 400m ² /kg；

S3, strong magnetic separation: uniformly mixing the pretreated stainless steel slag and red mud according to the proportion of 2:1, putting the mixture into a planetary mill for uniform mixing, and putting the mixed powder into a strong magnetic separator for magnetic separation to obtain metal fine selection powder 1 and powder 1;

s4, pretreatment of a calcareous raw material:

(3) Pretreatment of silicon-calcium slag: firstly, screening the calcium silicate slag, removing organic impurities in the calcium silicate slag, and then placing the calcium silicate slag in an electrothermal drying oven at 105 ℃ for drying for 12 hours for later use;

(4) Pretreatment of phosphate tailings: placing the phosphate tailings into a drying box at 105 ℃ for forced air drying until the water content is less than 1% for later use;

(3) The dried phosphate tailings and the dried calcium silicate slag are put into a planetary mill according to the proportion of 1:1 to be uniformly mixed, and then are put into a muffle furnace to be calcined, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 750 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the heat is preserved for 100min; cooling to room temperature by air blast after calcining, and taking out a sample; then the powder material cooled to room temperature is put into a ball mill, and ground to a specific surface area of 400m ² And (3) kg, obtaining a calcareous raw material for standby;

s5, pretreatment of a carbonaceous raw material:

(2) Waste fruit tree branch treatment: peeling waste fruit tree branches with the diameter of 5-35 mm, naturally drying the fruit tree branches outdoors for 1-3 months to reduce the water content to be lower than 10%, putting the crushed fruit tree branches into a 70 ℃ drying box for forced air drying to constant weight, and crushing the dried fruit tree branches to the particle size of 1-2 mm by adopting a crusher;

(3) Uniformly mixing the pretreated fruit tree branches and fir tree branch particles according to the mass ratio of 3:1 to obtain a carbonaceous raw material for later use;

s6, pretreatment of siliceous raw materials: crushing the photovoltaic panel in a jaw crusher to obtain particles with the particle size of 10-20 mm, drying the particles in an electrothermal drying oven, calcining the dried particles in a muffle furnace at 900 ℃, and preserving the heat for 100min; cooling to room temperature by air blast after calcining, and taking out a sample; grinding again to specific surface area 400m ² Kg, obtaining siliceous raw materials for later use;

s7, pretreatment of aluminum raw materials:

(4) Pretreatment of coal gasification residues: crushing coal gasification residues into particles with the diameter of 1-3 mm by a jaw crusher, and drying the crushed coal gasification residue particles at 105 ℃ for 12 hours for later use;

(5) Pretreatment of aluminum ash: firstly, screening aluminum ash, removing organic impurities in the aluminum ash, and then placing the aluminum ash in an electrothermal drying oven at 105 ℃ for drying for 12 hours;

(6) Mixing the pretreated coal gasification residues and aluminum ash residues according to the mass ratio of 1:1, and then placing the mixture into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 300m ² Kg, obtaining an aluminum raw material;

s8, press forming: the method comprises the steps of (1) placing the calcareous raw materials in powder materials 1 and S4, the carbonaceous raw materials in S5, the siliceous raw materials in S6 and the aluminum raw materials in S7 into a planetary mill according to the weight ratio of 40:14:18:15:13 respectively, and uniformly mixing; adding 8% of water into the obtained dry material mixture, then placing the mixture into a die, and pressing the mixture into pellets with the size of phi 30mm multiplied by 20mm by a hydraulic press; placing the pellets in an electric heating drying box at 100 ℃ and drying for 20min at constant temperature;

S9, high-temperature calcination: placing the pellets formed by compression in the step S8 into a covered corundum crucible, and placing the corundum crucible into a muffle furnace for high-temperature calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 800 ℃, wherein the temperature raising rate is 0.5 ℃/min, and then preserving the heat for 20min; then the temperature is increased to 1200 ℃ from 800 ℃ with the temperature increasing rate of 3.5 ℃/min, and then the temperature is kept for 120min; cooling to 1000 ℃ after calcining, taking out a sample, and quenching the taken sample to room temperature through water quenching;

s10, wet ore dressing: crushing the high-temperature calcined product obtained in the step S9 to 1-3 mm particles by using a jaw crusher, then performing wet grinding by using an RK/BK three-roller four-drum rod mill, performing wet separation in a weak magnetic field magnetic separation tube to obtain metal fine powder 2 and tailings modified powder, drying to obtain the metal fine powder 2 and tailings modified dry powder, and then placing the tailings modified dry powder into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 500m ² Kg, obtaining powder 2;

s11, pretreatment of powder 3:

(4) Dicyandiamide waste residue pretreatment: placing the dicyandiamide waste residue in an electrothermal drying oven at 105 ℃ for drying for 12 hours for standby;

(5) Pretreatment of waste stone powder: placing the waste stone powder into a drying box at 105 ℃ for forced air drying until the water content is less than 1%;

(6) The dried dicyandiamide waste residue and waste stone powder are put into a planetary mill according to the mass ratio of 2:1, and are evenly mixed, and then are put into a muffle furnace for calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 750 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the heat is preserved for 100min; taking out the sample after the calcination is completed and the air is cooled to room temperature, putting the powder cooled to the room temperature into a ball mill, and grinding the powder to a specific surface area of 400m ² Kg, obtaining powder 3;

s12, pretreatment of composite gypsum: respectively scattering the fluorogypsum and the desulfurized gypsum, then putting the fluorogypsum and the desulfurized gypsum into a blast drying oven at 50 ℃ for drying for 60 hours, uniformly mixing the dried fluorogypsum and desulfurized gypsum according to the mass ratio of 1:1, and then putting the fluorogypsum and desulfurized gypsum into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 300m ² Kg, obtaining powder 4;

s13, cement clinker pretreatment: cement is made up ofPlacing the clinker into a jaw crusher, crushing to 1-3 mm particles, drying the crushed cement clinker at 105 ℃ for 12h, and then placing the cement clinker into a cement ball mill with the rotating speed of 42r/min for grinding until the specific surface area is 300m ² /kg；

S14, preparing a water reducer: adding a isopentenyl alcohol polyoxyethylene ether macromer (IPEG) with the monomer mole number of 2mol into a reaction kettle, heating to 60-68 ℃ and starting stirring; adding Acrylic Acid (AA) with the mass ratio of IPEG of 4% and mercaptopropionic acid with the mass ratio of 0.7% into a dripping tank, and uniformly stirring and mixing to obtain dripping liquid; adding sodium persulfate with the mass ratio of 1% of IPEG into a reaction kettle after the IPEG macromonomer is completely melted, dropwise adding the dropwise adding liquid through a constant flow pump after the sodium persulfate is dissolved, wherein the total dropwise adding time is 4.0h, and adding sodium persulfate respectively in 2.0h and 3.0h, wherein the mass of the sodium persulfate added each time is 0.2% of that of the IPEG; after the dripping is finished, carrying out heat preservation and aging reaction for 1h, naturally cooling and hardening, and then crushing and grinding to obtain the solid polycarboxylate superplasticizer;

S15, preparing a composite cementing material: mixing the powder 2 obtained in the step S10, the powder 3 in the step S11, the powder 4 in the step S12 and the cement clinker in the step S13 according to the mass ratio of 55:15:15:15 to obtain a cementing material, adding the water reducer in the step S14 according to the mass of the cementing material of 0.1%, and adding Ca (NO) of 0.1% of the mass of the cementing material ₃ ) ₂ And finally, carrying out ball milling and mixing on the additive to obtain the composite cementing material.

The carbonization conditions in the step S1 are as follows: CO ₂ 15% concentration, 20+ -1deg.C, 85% + -1 humidity.

And the magnetic separation strength of the magnetic separator in the step S3 is 1T, and the rotating speed of the magnetic separator is 30r/min.

In the step S8, the pressure of the compression molding is 15MPa.

In the step S10, the wet grinding is carried out until the diameter of-0.074 mm is 91%, and the magnetic separation setting strength of the low-intensity magnetic separation tube is 1600Oe.

Example 2

s1, stainless steel slag pretreatment:placing 10-25 mm particle original stainless steel slag into a carbonization box for carbonization for 96 hours, placing the carbonized stainless steel slag into a 105 ℃ drying box for forced air drying to constant weight, crushing the stainless steel slag into particle with the particle size of 1-3 mm by a jaw crusher, and placing the particle into a ball mill for grinding until the specific surface area is 250m ² /kg；

S2, preprocessing red mud: stacking and airing the red mud to make the water content of the red mud be less than 10-15%, drying the red mud for 12 hours at 105 ℃, taking out the red mud, cooling the red mud in dry air, dispersing the red mud by adopting a planetary ball mill to make the specific surface area of the material reach 450m ² /kg；

S3, strong magnetic separation: uniformly mixing the pretreated stainless steel slag and red mud according to the proportion of 3:1, putting the mixture into a planetary mill for uniform mixing, and putting the mixed powder into a strong magnetic separator for magnetic separation to obtain metal fine selection powder 1 and powder 1;

s4, pretreatment of a calcareous raw material:

(5) Pretreatment of silicon-calcium slag: firstly, screening the calcium silicate slag, removing organic impurities in the calcium silicate slag, and then placing the calcium silicate slag in an electrothermal drying oven at 105 ℃ for drying for 12 hours for later use;

(6) Pretreatment of phosphate tailings: placing the phosphate tailings into a drying box at 105 ℃ for forced air drying until the water content is less than 1% for later use;

(3) The dried phosphate tailings and the dried calcium silicate slag are put into a planetary mill according to the proportion of 1:1.5 to be uniformly mixed, and then are put into a muffle furnace to be calcined, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 800 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the heat is preserved for 60min; cooling to room temperature by air blast after calcining, and taking out a sample; then the powder material cooled to room temperature is put into a ball mill and ground to a specific surface area of 500m ² And (3) kg, obtaining a calcareous raw material for standby;

s5, pretreatment of a carbonaceous raw material:

(3) Waste fruit tree branch treatment: peeling waste fruit tree branches with the diameter of 5-35 mm, naturally drying the fruit tree branches outdoors for 1-3 months to reduce the water content to be lower than 10%, putting the crushed fruit tree branches into a 70 ℃ drying box for forced air drying to constant weight, and crushing the dried fruit tree branches to the particle size of 1-2 mm by adopting a crusher;

(3) Uniformly mixing the pretreated fruit tree branches and fir tree branch particles according to the mass ratio of 1.5:1 to obtain a carbonaceous raw material for later use;

s6, pretreatment of siliceous raw materials: crushing the photovoltaic panel in a jaw crusher to obtain particles with the particle size of 10-20 mm, drying in an electrothermal drying oven, calcining the dried particles in a muffle furnace at 1100 ℃, and preserving the heat for 75min; cooling to room temperature by air blast after calcining, and taking out a sample; grinding again to a specific surface area of 500m ² Kg, obtaining siliceous raw materials for later use;

s7, pretreatment of aluminum raw materials:

(7) Pretreatment of coal gasification residues: crushing coal gasification residues into particles with the diameter of 1-3 mm by a jaw crusher, and drying the crushed coal gasification residue particles at 105 ℃ for 12 hours for later use;

(8) Pretreatment of aluminum ash: firstly, screening aluminum ash, removing organic impurities in the aluminum ash, and then placing the aluminum ash in an electrothermal drying oven at 105 ℃ for drying for 12 hours;

(9) Mixing the pretreated coal gasification residues and aluminum ash residues according to the mass ratio of 1:1.5, and then putting the mixture into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 350m ² Kg, obtaining an aluminum raw material;

s8, press forming: the method comprises the steps of (1) placing the calcareous raw materials in powder materials 1 and S4, the carbonaceous raw materials in S5, the siliceous raw materials in S6 and the aluminum raw materials in S7 into a planetary mill according to the weight ratio of 36:21:20:10:13 respectively, and uniformly mixing; adding water accounting for 10% of the mass of the obtained dry material mixture into the dry material mixture, then placing the mixture into a die, and pressing the mixture into pellets with the size of phi 30mm multiplied by 20mm through a hydraulic press; placing the pellets in an electric heating drying box at 100 ℃ and drying for 30min at constant temperature;

s9, high-temperature calcination: placing the pellets formed by compression in the step S8 into a covered corundum crucible, and placing the corundum crucible into a muffle furnace for high-temperature calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 800 ℃, wherein the temperature raising rate is 0.5 ℃/min, and then preserving the heat for 20min; then the temperature is increased to 1250 ℃ from 800 ℃ to the required temperature, the heating rate is 3.5 ℃/min, and then the temperature is kept for 80min; cooling to 1050 ℃ after calcining, taking out a sample, and quenching the taken sample to room temperature through water quenching;

S10, wet ore dressing: crushing the high-temperature calcined product obtained in the step S9 to 1-3 mm particles by using a jaw crusher, then performing wet grinding by using an RK/BK three-roller four-drum rod mill, performing wet separation in a weak magnetic field magnetic separation tube to obtain metal fine powder 2 and tailings modified powder, drying to obtain the metal fine powder 2 and tailings modified dry powder, and then placing the tailings modified dry powder into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 600m ² Kg, obtaining powder 2;

s11, pretreatment of powder 3:

(7) Dicyandiamide waste residue pretreatment: placing the dicyandiamide waste residue in an electrothermal drying oven at 105 ℃ for drying for 12 hours for standby;

(8) Pretreatment of waste stone powder: placing the waste stone powder into a drying box at 105 ℃ for forced air drying until the water content is less than 1%;

(9) The dried dicyandiamide waste residue and waste stone powder are put into a planetary mill according to the mass ratio of 2:1, and are evenly mixed, and then are put into a muffle furnace for calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 850 ℃ from 300 ℃ to the required temperature, the heating rate is 10 ℃/min, and then the heat is preserved for 70min; taking out the sample after the calcination is completed and the air is cooled to room temperature, putting the powder cooled to room temperature into a ball mill, and grinding to a specific surface area of 500m ² Kg, obtaining powder 3;

s12, pretreatment of composite gypsum: respectively scattering the fluorogypsum and the desulfurized gypsum, then placing the fluorogypsum and the desulfurized gypsum into a blast drying oven at 60 ℃ for drying for 54 hours, uniformly mixing the dried fluorogypsum and desulfurized gypsum according to the mass ratio of 1:1.5, and then placing the mixture into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 350m ² Kg, obtaining powder 4;

s13, cement clinker pretreatment: placing the cement clinker into a jaw crusher, crushing the cement clinker into particles with the particle size of 1-3 mm, drying the crushed cement clinker for 12 hours at the temperature of 105 ℃, and then placing the cement clinker into a cement ball mill with the rotating speed of 42r/min for grinding until the specific surface area is 350m ² /kg；

S14, preparing a water reducer: adding 3mol of isopentenyl alcohol polyoxyethylene ether macromonomer (IPEG) into a reaction kettle, heating to 60-68 ℃ and stirring; adding 18% Acrylic Acid (AA) with the mass ratio of IPEG and 0.8% mercaptopropionic acid into a dripping tank, and uniformly stirring and mixing to obtain dripping liquid; adding sodium persulfate with the mass ratio of 1.2% of IPEG into a reaction kettle after the IPEG macromonomer is completely melted, dropwise adding the dropwise adding liquid through a constant flow pump after the sodium persulfate is dissolved, wherein the total dropwise adding time is 4.0h, and adding sodium persulfate respectively in 2.0h and 3.0h, wherein the mass of the sodium persulfate added each time is 0.2% of that of the IPEG; after the dripping is finished, carrying out heat preservation and aging reaction for 1.25 hours, naturally cooling and hardening, and then crushing and grinding to obtain the solid polycarboxylate superplasticizer;

S15, preparing a composite cementing material: mixing the powder 2 obtained in S10, the powder 3 in S11, the powder 4 in S12 and the cement clinker in S13 according to the mass ratio of 65:10:15:10 to obtain a curing agent cementing material, adding a water reducing agent in S14 according to the mass of 0.15% of the curing agent cementing material, and adding Ca (NO) of 0.21% of the mass of the curing agent cementing material ₃ ) ₂ And finally, grinding and ball milling the additive to uniformly mix the additive to obtain the composite cementing material.

The carbonization conditions in the steps S1 and S2 are as follows: CO ₂ Concentration 20%, temperature 20+ -1deg.C, humidity 85% + -1.

And the magnetic separation strength of the magnetic separator in the step S3 is 2T, and the rotating speed of the magnetic separator is 20r/min.

In the step S7, the pressure of the compression molding is 20MPa.

In the step S9, the wet grinding is carried out until the diameter of-0.074 mm is 94.3%, and the magnetic separation setting strength of the low-intensity magnetic separation tube is 1700Oe.

Example 3

s1, stainless steel slag pretreatment: placing 10-25 mm particle original stainless steel slag into a carbonization box for carbonization for 120 hours, placing the carbonized stainless steel slag into a 105 ℃ drying box for forced air drying to constant weight, crushing the stainless steel slag into particles with the particle size of 1-3 mm by a jaw crusher, and placing the particles into a ball mill for grinding until the specific surface area is 200m ² /kg；

S2, preprocessing red mud: stacking and airing the red mud to make the water content of the red mud be less than 10-15%, drying the red mud for 12 hours at 105 ℃, taking out the red mud, cooling the red mud in dry air, dispersing the red mud by adopting a planetary ball mill to make the specific surface area of the material reach 550m ² /kg；

S3, strong magnetic separation: uniformly mixing the pretreated stainless steel slag and red mud according to the proportion of 4:1, putting the mixture into a planetary mill for uniform mixing, and putting the mixed powder into a strong magnetic separator for magnetic separation to obtain metal fine selection powder 1 and powder 1;

s4, pretreatment of a calcareous raw material:

(7) Pretreatment of silicon-calcium slag: firstly, screening the calcium silicate slag, removing organic impurities in the calcium silicate slag, and then placing the calcium silicate slag in an electrothermal drying oven at 105 ℃ for drying for 12 hours for later use;

(8) Pretreatment of phosphate tailings: placing the phosphate tailings into a drying box at 105 ℃ for forced air drying until the water content is less than 1% for later use;

(3) The dried phosphate tailings and the dried calcium silicate slag are put into a planetary mill according to the proportion of 1:2 to be uniformly mixed, and then are put into a muffle furnace to be calcined, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 900 ℃ from 300 ℃ with the heating rate of 10 ℃/min, and then the heat is preserved for 50min; cooling to room temperature by air blast after calcining, and taking out a sample; then the powder material cooled to room temperature is put into a ball mill, and ground to the specific surface area of 600m ² And (3) kg, obtaining a calcareous raw material for standby;

s5, pretreatment of a carbonaceous raw material:

(4) Waste fruit tree branch treatment: peeling waste fruit tree branches with the diameter of 5-35 mm, naturally drying the fruit tree branches outdoors for 1-3 months to reduce the water content to be lower than 10%, putting the crushed fruit tree branches into a 70 ℃ drying box for forced air drying to constant weight, and crushing the dried fruit tree branches to the particle size of 1-2 mm by adopting a crusher;

(3) Uniformly mixing the pretreated fruit tree branches and fir tree branch particles according to the mass ratio of 1:2 to obtain a carbonaceous raw material for later use;

s6, pretreatment of siliceous raw materials: crushing the photovoltaic panel in a jaw crusher to obtain particles with the particle size of 10-20 mm, drying in an electrothermal drying oven, calcining the dried particles in a muffle furnace at 1300 ℃, and preserving the heat for 50min; cooling to room temperature by air blast after calcining, and taking out a sample; grinding again to a specific surface area of 600m ² Kg, obtaining siliceous raw materials for later use;

s7, pretreatment of aluminum raw materials:

(10) Pretreatment of coal gasification residues: crushing coal gasification residues into particles with the diameter of 1-3 mm by a jaw crusher, and drying the crushed coal gasification residue particles at 105 ℃ for 12 hours for later use;

(11) Pretreatment of aluminum ash: firstly, screening aluminum ash, removing organic impurities in the aluminum ash, and then placing the aluminum ash in an electrothermal drying oven at 105 ℃ for drying for 12 hours;

(12) Mixing the pretreated coal gasification residues and aluminum ash residues according to the mass ratio of 1:2, and then putting the mixture into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 400m ² Kg, obtaining an aluminum raw material;

s8, press forming: the method comprises the steps of (1) placing the calcareous raw materials in powder materials 1 and S4, the carbonaceous raw materials in S5, the siliceous raw materials in S6 and the aluminum raw materials in S7 into a planetary mill according to the weight ratio of 30:21:25:15:9 respectively, and uniformly mixing; adding 11% of water into the obtained dry material mixture, then placing the mixture into a die, and pressing the mixture into pellets with the size of phi 30mm multiplied by 20mm by a hydraulic press; placing the pellets in an electric heating drying box at 100 ℃ and drying for 40min at constant temperature;

s9, high-temperature calcination: placing the pellets formed by compression in the step S8 into a covered corundum crucible, and placing the corundum crucible into a muffle furnace for high-temperature calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 800 ℃, wherein the temperature raising rate is 0.5 ℃/min, and then preserving the heat for 20min; then the temperature is increased to 1300 ℃ from 800 ℃ at the heating rate of 3.5 ℃/min, and then the temperature is kept for 30min; cooling to 1100 ℃ after calcining, taking out a sample, and quenching the taken sample to room temperature through water quenching;

S10, wet ore dressing: crushing the high-temperature calcined product obtained in the step S9 to 1-3 mm particles by using a jaw crusher, then performing wet grinding by using an RK/BK three-roller four-drum rod mill, performing wet separation in a weak magnetic field magnetic separation tube to obtain metal fine powder 2 and tailings modified powder, drying to obtain the metal fine powder 2 and tailings modified dry powder, and then placing the tailings modified dry powder into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 700m ² Kg, obtaining powder 2;

s11, pretreatment of powder 3:

(10) Dicyandiamide waste residue pretreatment: placing the dicyandiamide waste residue in an electrothermal drying oven at 105 ℃ for drying for 12 hours for standby;

(11) Pretreatment of waste stone powder: placing the waste stone powder into a drying box at 105 ℃ for forced air drying until the water content is less than 1%;

(12) The dried dicyandiamide waste residue and waste stone powder are put into a planetary mill according to the mass ratio of 2:1, and are evenly mixed, and then are put into a muffle furnace for calcination, wherein the calcination system is as follows: raising the temperature from room temperature to 300 ℃, keeping the temperature for 25min after the temperature raising rate is 5 ℃/min; then the temperature is increased to 900 ℃ from 300 ℃ with the heating rate of 10 ℃/min, and then the heat is preserved for 50min; taking out the sample after the calcination is completed and the air is cooled to room temperature, putting the powder cooled to room temperature into a ball mill, and grinding to a specific surface area of 600m ² Kg, obtaining powder 3;

s12, pretreatment of composite gypsum: scattering the fluorogypsum and the desulfurized gypsum respectively, then putting the fluorogypsum and the desulfurized gypsum into a blast drying oven at 70 ℃ for drying for 48 hours, and uniformly mixing the dried fluorogypsum and desulfurized gypsum according to the mass ratio of 1:2 to obtain the productThen put into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area of 400m ² Kg, obtaining powder 4;

s13, cement clinker pretreatment: placing the cement clinker into a jaw crusher, crushing the cement clinker into particles with the particle size of 1-3 mm, drying the crushed cement clinker for 12 hours at the temperature of 105 ℃, and then placing the cement clinker into a cement ball mill with the rotating speed of 42r/min for grinding until the specific surface area is 400m ² /kg；

S14, preparing a water reducer: adding a prenyl alcohol polyoxyethylene ether macromonomer (IPEG) with the monomer mole number of 4mol into a reaction kettle, heating to 60-68 ℃ and starting stirring; adding 30% of Acrylic Acid (AA) with the mass ratio of IPEG and 1% of mercaptopropionic acid into a dripping tank, and uniformly stirring and mixing to obtain dripping liquid; adding sodium persulfate with the mass ratio of 1.5% of IPEG into a reaction kettle after the IPEG macromonomer is completely melted, dropwise adding the dropwise adding liquid through a constant flow pump after the sodium persulfate is dissolved, wherein the total dropwise adding time is 4.0h, and adding sodium persulfate respectively in 2.0h and 3.0h, wherein the mass of the sodium persulfate added each time is 0.2% of that of the IPEG; after the dripping is finished, carrying out heat preservation and aging reaction for 1.5 hours, naturally cooling and hardening, and then crushing and grinding to obtain the solid polycarboxylate superplasticizer;

S15, preparing a composite cementing material: mixing the powder 2 obtained in S10, the powder 3 in S11, the powder 4 in S12 and the cement clinker in S13 according to the mass ratio of 75:10:10:5 to obtain a curing agent cementing material, adding a water reducing agent in S14 according to the mass of the curing agent cementing material of 0.2%, and adding Ca (NO) of 0.3% of the mass of the curing agent cementing material ₃ ) ₂ And finally, grinding and ball milling the additive to uniformly mix the additive to obtain the composite cementing material.

The carbonization conditions in the step S1 are as follows: CO ₂ Concentration 30%, temperature 20+ -1deg.C, humidity 85% + -1.

And the magnetic separation strength of the magnetic separator in the step S3 is 3T, and the rotating speed of the magnetic separator is 10r/min.

In the step S7, the pressure of the compression molding is 25MPa.

In the step S9, the wet grinding is carried out until the diameter of-0.074 mm is 95.8%, and the magnetic separation strength of the low-intensity magnetic separation tube is 1800Oe.

In examples 1 to 3, the main chemical components and contents of the stainless steel slag in the step S1 are as follows: al (Al) ₂ O ₃ 5～10％，SiO ₂ 16～20％，CaO 9～48％，MgO 2～8％，Fe ₂ O ₃ 27％～31％，MnO 1～6％，Cr ₂ O ₃ 4-10%; the main chemical composition of the red mud in the step S2 is as follows: siO (SiO) ₂ 10～25％，Al ₂ O ₃ 20～30％，Fe ₂ O ₃ 30～40％，MgO 0.1～2％，CaO 5～15％，K ₂ O 0.01～1％，Na ₂ O 1～10％，TiO ₂ 1-8% and loss on ignition 9-15%. In the step S4, main mineral components of the phosphate tailing comprise dolomite, quartz, fluorapatite and a small amount of calcite, and the main chemical components and the content are as follows: siO (SiO) ₂ 2～5％，Al ₂ O ₃ 0.2～1％，Fe ₂ O ₃ 1～6％，MgO 10～18％，CaO 25～35％，Na ₂ O 0.01～1％，K ₂ O 0.01～1％，CO ₂ 25～40％，MnO0.1～1％，P ₂ O ₅ 1 to 8 percent; the main chemical composition of the silicon-calcium slag is as follows: siO (SiO) ₂ 20～30％，Al ₂ O ₃ 5～15％，Fe ₂ O ₃ 2-3 percent of MgO, 2-3 percent of MgO and 40-55 percent of CaO; the chemical composition and industrial analysis of the waste fruit tree branches in the step S5 are as follows: 35-45% of C, 5-10% of H, 45-55% of O, 0.1-1% of N, 0.1-2% of S, 5-12% of water, 1-2% of ash, 75-90% of volatile matters and 5-8% of fixed carbon; the chemical composition and industrial analysis of fir branches are as follows: 40-55% of C, 5-8% of H, 43-52% of O, 0.8-1.2% of N, 0.4-0.9% of S, 16-21% of water, 3-6% of ash, 65-78% of volatile matter and 27-36% of fixed carbon. The chemical components of the waste photovoltaic panel in the step S6 are as follows by mass percent: siO (SiO) ₂ 65～75％，NaCl 20～40％，CaCl ₂ 0.01 to 3.5 percent, the loss on ignition is 0.01 to 4 percent, and the other is 0.01 to 2.5 percent; the main chemical composition of the coal gasification residue in step S7 is: siO (SiO) ₂ 35～65％，Al ₂ O ₃ 12～20％，Fe ₂ O ₃ 15～20％，MgO 3～7％，CaO 5～18％，K ₂ O 2～3％，Na ₂ O 2～3％，SO ₃ 0.1～1.5％，P ₂ O ₅ 0.01 to 1 percent, tiO20.1 to 2 percent, and loss on ignition 15 to 40 percent; in the step S7, the aluminum ash is fine ash after separating out metal aluminum, and the main chemical components and contents are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 45～75％，AlN 20～25％，AlCl ₃ 2～6％，AlF ₃ 1 to 6 percent and 8 to 30 percent of loss on ignition. In the step S11, the dry basis granularity of dicyandiamide waste residue is 0.01-0.1 mm, the main mineral composition is calcite, and the main chemical components and the content are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 1～8％，CaO 45～65％，Fe ₂ O ₃ 1～8％，MgO 0.01～4％，K ₂ O+Na ₂ 0.01 to 3 percent of O, 5 to 25 percent of C and 20 to 35 percent of loss on ignition; in the step S11, the waste stone powder is waste generated in the sand making process of the machine-made sand, and the main chemical components and the content are as follows: siO (SiO) ₂ 5～30％，Al ₂ O ₃ 1～8％，CaO 45～65％，Fe ₂ O ₃ 1～6％，MgO 3～8％，K ₂ O+Na ₂ 0.01 to 3 percent of O and 20 to 35 percent of loss on ignition; the main chemical components and the content of the fluorine gypsum in the step S12 are as follows: caO 35-40%, siO ₂ 0.2～6％，Al ₂ O ₃ 0.2～4％，MgO 0.1～1％，SO ₃ 35～50％，CaF ₂ 2-8%; the main chemical components and the content of the desulfurized gypsum in the step S12 are as follows: SO (SO) ₃ 30～55％，CaO 20～45％，SiO ₂ 2～4％，P ₂ O ₅ 1～3.5％，MgO0.01～2.5％，Na ₂ O 0.01～1.5％，Fe ₂ O ₃ 0.01～6％，K ₂ 0.01 to 1.5 percent of O, 15 to 30 percent of loss on ignition and 0.01 to 1 percent of other components.

Detection and analysis:

the important intermediate products in examples 1-3 and the finally prepared solid waste-based high-performance concrete were subjected to detection analysis, and the results are as follows:

table 1 index analysis of the metal beneficiated powder of examples 1-3

TABLE 2 chemical analysis of powder 2 in examples 1-3

TABLE 3 Activity index of powder 2 in examples 1-3

The effective CaO content in the powder 3 prepared in the step S11 in the embodiment 1 is 69%, the MgO content is less than 3%, the digestion temperature is 67 ℃, the digestion time is 11min, the screen residue of a 0.08 square hole screen is 9%, and the powder meets the requirements of ASTM C5-2010 Standard Specification for quicklime for construction.

In the powder material 3 prepared in the step S11 in the embodiment 2, the effective CaO content is 71%, the MgO content is less than 3%, the digestion temperature is 69 ℃, the digestion time is 10min, the screen residue of a 0.08 square hole screen is 12%, and the requirements of ASTM C5-2010 Standard Specification for quick lime for construction are met.

In the powder material 3 prepared in the step S11 in the embodiment 3, the effective CaO content is 71%, the MgO content is less than 3%, the digestion temperature is 68 ℃, the digestion time is 13min, the screen residue of a 0.08 square hole screen is 13%, and the requirements of ASTM C5-2010 Standard Specification of quicklime for construction are met.

Table 4 technical indicators of composite cementing materials in examples 1-3

Heavy metal leaching experiments: according to GB17671-1999 cement mortar strength test method, mortar samples of mine filling materials are prepared respectively, the sizes of the samples are 40mm multiplied by 160mm, curing is carried out under the standard condition that the temperature is 35 ℃ and the humidity is more than 95%, and the leaching concentration of heavy metals in 28-year period is tested.

Table 5 examples 1-3 of composite cement sample curing 28d ion Leaching (μg/L)

Radioactivity measurement: radioactivity was measured according to the relevant regulations of the current national standard "limit of radionuclides for building materials" GB 6566.

TABLE 6 implementation of the results of the radioactivity test on the composite cement samples of examples 1-3

The activated composite cementing material was mixed with P.O42.5 Portland cement in an amount of 15%, 25%, 35% and 45%, and a cement mortar test piece was prepared and the strength was measured according to International Standard GB/T17671-1999 cement mortar Strength test method (ISO method) (see Table 7).

Table 7 cement sand strength of composite cement incorporated with water reducer in examples 1-3

Table 8 gel strength of composite gel without Water reducing agent in examples 1-3

EXAMPLE 2 analysis of hydration Properties of composite gel Material

Fig. 7 is an exothermic rate of cement and composite cement (SL) during hydration. As can be seen from the graph (a), the hydration process of the composite cementing material is similar to that of cement The method is divided into 5 stages of induction early stage, induction period, acceleration period, deceleration period and stable period. After injection of water, the first exotherm occurred rapidly. The induction period is entered after the end of the first exothermic peak, at which time the hydration rate is reduced. Due to hydration product Ca (OH) ₂ And C-S-H gel only in Ca ²⁺ Crystallization begins when the concentration reaches saturation. Therefore, after the hydration is carried out in the first stage, the hydration rate is obviously and rapidly reduced, and the induction period of the composite cementing material is slower than that of cement because the composite cementing material contains some inert phases, and the heat release rate of the composite cementing material in the five stages is lower than that of cement. Graph (b) is the total amount of heat of hydration of the composite cement and cement, which is lower than cement due to the low early reactivity of the composite cement.

Example 2 composition and Structure of composite cementitious paste Condition product

Fig. 8 is an XRD pattern of the net slurry of the composite cementitious material, fig. 8 (a) is an XRD pattern of hydration products of the net slurry of the composite cementitious material at different ages, and fig. 8 (b) is a comparison of hydration products of the net slurry of the composite material and the net slurry of the cement at 28d ages. As is clear from the figure, the 28-day hydration product was identified as ettringite (Ca) by XRD analysis ₆ Al ₂ [SO ₄ ] ₃ (OH) ₁₂ ·26H ₂ O) and calcium silicate hydrate (C-S-H gel). P.O 42.5.5 Cement 28-day hydration product is predominantly calcite (Ca (OH) ₂ ) C-S-H gel and ettringite. In addition, gypsum (CaSO) which is not completely reacted can be found in the hydration product ₄ ·2H ₂ O). As is clear from XRD analysis, the types of hydration products differ from ordinary portland cement by the composite cement: ca (OH) in XRD spectrum of 28-day hydration product of ordinary Portland cement ₂ The diffraction peak intensity is larger, and the Ca (OH) 2 characteristic diffraction peak is lower in the XRD spectrum of the composite gel material sample.

FIG. 9 shows the FT-IR spectrum of a steel slag-slag based cement paste test block. As can be seen in fig. 9: at 3406cm ^-1 And 1622cm ^-1 Is the bending vibration peak of O-H bond, the O-H group is mainly derived from water and hydroxide, and can be from 3, 7 to 28dThe absorption peak is obviously increased, the hydration reaction is continuously carried out, water participates in the hydration reaction to be changed into adsorbed water or substances containing crystals are generated, the hydroxyl content in the system is gradually increased, and the hydration products are also gradually increased; 1402cm ^-1 Belonging to CO ₃ ^2- The asymmetric stretching vibration band of (2) indicates that the sample is carbonized, and the sample and CO in the air are prepared ₂ The reaction is carried out to carbonize the sample, but the peak height of the absorption peak does not change obviously in the subsequent hydration; 1120cm ^-1 The asymmetric stretching vibration band of Si-O is adopted, so that the transmittance of Si-O of 3d is larger than that of 28d, and the fact that more Si-O breaks, bond energy is reduced, absorption peak is weakened and more AFt crystals and C-S-H gel are generated along with the increase of curing age is shown.

At 969cm ^-1 The absorption peak of Si-O symmetrical telescopic vibration is gradually slowed down, which indicates that silicate minerals in the clean slurry system are more complex at the moment, and C-A-S-H gel and C-S-H gel are generated; 671cm ^-1 The bending vibration bands of Si-O-Si bonds at 7d and 28d are almost disappeared; 603cm ^-1 The bending vibration band of Si-O-Si bond is located, and the peak height of the absorption peak has no obvious change. As the hydration reaction proceeds, the absorption peaks change from 3, 7 to 28d in the figure, and more AFt crystals and C-S-H gels are produced.

FIG. 10 is a test result of TG/DSC of composite cement hydrated for 28 days. The weight loss in TG curves is mainly caused by mineral loss of water or carbonate mineral decomposition. The water in minerals is structural water, crystal water, interlayer water, colloid water and adsorbed water. The removal of the structural water is difficult, and the dehydration temperature is approximately 600-900 ℃; the dehydration temperature of the crystal water is approximately 450-600 ℃; the dehydration temperatures of the interlaminar water, the colloidal water and the adsorbed water are relatively low. As can be seen from FIG. 10 (a), two distinct endothermic peaks appear at 55℃to 100℃and at 110℃to 135℃respectively, and the weightlessness in the two intervals is 7.047% and 7.06%, respectively. A number of studies have shown that the weight loss below 100℃is mainly due to dehydration of the adsorbed water in the hydration product and the coordinated water in the ettringite, at 50-100℃the 2 main vertices of ettringite and 24 The secondary vertex water is gradually lost; the exothermic characteristic peak corresponding to 110-135 ℃ is caused by dehydration of substances such as C-S-H gel and the like in the heating process. Although there is no significant endothermic peak at 160℃to 500℃the loss of weight still occurs slowly and continuously, the total loss of weight in this interval being 3.623%, the cause of this loss of weight being due on the one hand to the loss of part of the crystal water in the hydration product, such as Al (OH) in ettringite ₆ ^3- By OH in octahedra ^- There are 6 crystal waters in the form of crystals, 4 of which are gradually lost at 160℃to 260 ℃. The TG curve of fig. 10 (a) also shows a weight loss of 17.73% below 500 ℃ due to dehydration of the hydration product. The water loss of the ordinary silicate hydration product in the temperature range is 8.50%, the weight loss of the composite cementing material hydration hardening body in the temperature range is 208.6% of the weight loss of the ordinary silicate cement hardening body, and the result shows that the product generated by the hydration of the composite cementing material can be more than consolidated by more than one time than the cement hydration process, so that the dehydration in the hydration process can be relieved or avoided. The good water-fixing performance in the hydration process of the composite cementing material is due to the fact that partial hydration products with high crystal water, such as ettringite, are generated, and the water molecules account for 81.16% of the whole volume of the ettringite, so that a large amount of free water can be absorbed in the formation process. In FIG. 10 (b), there are many tiny complex endothermic peaks between 500℃and 900℃which are characteristic endothermic peaks due to the removal of structural water or the decomposition of carbonates by hydration products, and these peaks are complex and dense, indicating that these species are of a wide variety but not in large amounts. In addition, the exothermic peak around 850 ℃ is a characteristic peak of C-S-H gel structure transition; the large endothermic peak around 1000 ℃ is the melting endothermic peak of the system.

FIG. 11 is an SEM image of a static paste of composite cementitious material after curing to different ages, immediately terminating its hydration with an absolute ethanol solution. FIG. 11 (a) is an SEM image at 3000 magnification of a 3d sample cured under standard conditions, the early hydration product of the sample being a large amount of needle, rod-like material, the majority of which is ettringite and C-S-H gel; FIG. 11 (b) is a photograph of a sample magnified 10000 times, from which a large amount of fibrous materials are seen to cross-lap each other, indicating that hydration reaction is proceeding, so that performance is enhanced, and that a large amount of spherical particles are seen to remain unreacted around the cavity. FIGS. 11 (C) and (d) are SEM images of hardened samples for 7 days, and it can be seen that a large number of ettringite crystals have been encapsulated by C-S-H gel, that needle and rod-like crystal substances have been reduced, that hydration reaction has been sufficient, that voids of the static mass sample in FIG. 11 (d) have been filled with hydrated calcium silicate, ettringite and unreacted SiO2 produced by hydration, and that the compactibility has been relatively dense. FIGS. 11 (e) and (f) are SEM images of a sample for 28 days, in which the particles formed are densely packed and interpenetrated, the reaction is basically finished, gaps between the particles and the gel filled with the product are tightly bonded, the gaps are less, and the mechanical properties are more excellent.

In conclusion, the invention can effectively utilize valuable metals in metallurgical solid wastes (stainless steel slag and red mud), realize the cooperative utilization of industrial solid wastes, ocean solid wastes and agricultural solid wastes, realize the aim of energy conservation and environmental protection, and can treat wastes with the wastes, thereby providing a new direction for the recycling application of solid wastes while reducing the environmental protection pressure of mining areas, construction sites and agricultural production, promoting the building production to advance towards the aim of carbon reaching peak and carbon neutralization, and realizing the cooperative and efficient development of building industrialization and solid waste recycling. The invention has great environmental protection value and economic benefit.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but it should be understood that any modifications, equivalents, improvements, etc. falling within the spirit and principles of the present invention will fall within the scope of the present invention.

Claims

1. A method for preparing a composite cementing material by utilizing tailings after multi-element solid waste iron extraction comprises the following steps:

S2, preprocessing red mud: piling up and airing the red mud to make it contain waterThe weight is less than 10-15%, then the mixture is dried for 12 hours at 105 ℃, taken out and cooled in dry air, and the mixture is dispersed by adopting a planetary ball mill, so that the specific surface area of the material reaches 400-550 m ² /kg；

S4, pretreatment of a calcareous raw material:

s5, pretreatment of a carbonaceous raw material:

s6, pretreatment of siliceous raw materials: crushing the photovoltaic panel in a jaw crusher to obtain particles with the particle size of 10-20 mm, then drying the particles in an electrothermal drying oven, calcining the dried particles in a muffle furnace at 900-1300 ℃, and preserving the temperature for 50-100 min; cooling to room temperature by air blast after calcining, and taking out a sample; grinding again to a specific surface area of 400-600 m ² Kg, obtaining siliceous raw materials for later use;

s7, pretreatment of aluminum raw materials:

S10, wet ore dressing: crushing the high-temperature calcined product obtained in the step S9 to 1-3 mm particles by using a jaw crusher, then performing wet grinding by using an RK/BK three-roller four-drum rod mill, performing wet separation in a weak magnetic field magnetic separation tube to obtain metal fine powder 2 and tailings modified powder, drying to obtain the metal fine powder 2 and tailings modified dry powder, and then placing the tailings modified dry powder into a cement ball mill with the rotating speed of 48r/min for grinding until the specific surface area is 500-700 m ² Kg, obtaining powder 2;

s11, pretreatment of powder 3:

s13, cement clinker pretreatment: placing the cement clinker into a jaw crusher, crushing the cement clinker into particles with the particle size of 1-3 mm, drying the crushed cement clinker for 12 hours at the temperature of 105 ℃, and then placing the cement clinker into a cement ball mill with the rotating speed of 42r/min for grinding to the specific surfaceThe product is 300-400 m ² /kg；

2. The method for preparing a composite cementitious material of claim 1, wherein the step S1 carbonization conditions are: CO ₂ The concentration is 15-25%, the temperature is 20+ -1 ℃, and the humidity is 85% + -1.

3. The method for preparing the composite cementing material according to claim 1, wherein the magnetic separation strength of the magnetic separator in the step S3 is 1-3T, and the rotating speed of the magnetic separator is 10-30 r/min.

4. The method for preparing a composite cement according to claim 1, wherein in the step S8, the pressure of the press forming is 15 to 25MPa.

5. The method for preparing the composite cementing material according to claim 1, wherein in the step S10, wet grinding is performed until the diameter of-0.074 mm is more than 90% -95%, and the strength of the magnetic separation setting of the low-intensity magnetic separation tube is 1600-1800 Oe.

6. The method for preparing composite cementitious material according to claim 1, wherein the main chemical components and contents of the stainless steel slag in step S1 are: al (Al) ₂ O ₃ 5～10％，SiO ₂ 16～20％，CaO9～48％，MgO2～8％，Fe ₂ O ₃ 27％～31％，MnO1～6％，Cr ₂ O ₃ 4-10%; the main chemical composition of the red mud in the step S2 is as follows: siO (SiO) ₂ 10～25％，Al ₂ O ₃ 20～30％，Fe ₂ O ₃ 30～40％，MgO0.1～2％，CaO5～15％，K ₂ O0.01～1％，Na ₂ O1～10％，TiO ₂ 1-8% and loss on ignition 9-15%.

7. The method for preparing composite cementing material according to claim 1, wherein the main mineral composition of the phosphate tailings in the step S4 is dolomite, quartz, fluorapatite and a small amount of calcite, and the main chemical components and contents thereof are as follows: siO (SiO) ₂ 2～5％，Al ₂ O ₃ 0.2～1％，Fe ₂ O ₃ 1～6％，MgO10～18％，CaO25～35％，Na ₂ O0.01～1％，K ₂ O0.01～1％，CO ₂ 25～40％，MnO0.1～1％，P ₂ O ₅ 1 to 8 percent; the main chemical composition of the silicon-calcium slag is as follows: siO (SiO) ₂ 20～30％，Al ₂ O ₃ 5～15％，Fe ₂ O ₃ 2-3 percent of MgO, 2-3 percent of MgO and 40-55 percent of CaO; the chemical composition and industrial analysis of the waste fruit tree branches in the step S5 are as follows: 35-45% of C, 5-10% of H, 45-55% of O, 0.1-1% of N, 0.1-2% of S, 5-12% of water, 1-2% of ash, 75-90% of volatile matters and 5-8% of fixed carbon; the chemical composition and industrial analysis of the fir branches are as follows: 40 to 55 percent of C, 5 to 8 percent of H, 43 to 52 percent of O, 0.8 to 1.2 percent of N, 0.4 to 0.9 percent of S and 1 percent of water6-21%, ash content 3-6%, volatile matter 65-78%, and fixed carbon 27-36%.

8. The method for preparing a composite cementitious material according to any one of claims 1 to 7, wherein the chemical components of the waste photovoltaic panel in step S6 are as follows in mass percent: siO (SiO) ₂ 65～75％，NaCl20～40％，CaCl ₂ 0.01 to 3.5 percent, the loss on ignition is 0.01 to 4 percent, and the other is 0.01 to 2.5 percent; the main chemical composition of the coal gasification residue in the step S7 is as follows: siO (SiO) ₂ 35～65％，Al ₂ O ₃ 12～20％，Fe ₂ O ₃ 15～20％，MgO3～7％，CaO5～18％，K ₂ O2～3％，Na ₂ O2～3％，SO ₃ 0.1～1.5％，P ₂ O ₅ 0.01 to 1 percent, tiO20.1 to 2 percent, and loss on ignition 15 to 40 percent; in the step S7, the aluminum ash is fine ash after separating out metal aluminum, and the main chemical components and contents are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 45～75％，AlN20～25％，AlCl ₃ 2～6％，AlF ₃ 1 to 6 percent and 8 to 30 percent of loss on ignition.

9. The method for preparing the composite cementing material according to claim 8, wherein the dicyandiamide waste residue in the step S11 has a dry basis granularity of 0.01-0.1 mm, and the main mineral composition is calcite, and the main chemical components and the content thereof are as follows: siO (SiO) ₂ 5～20％，Al ₂ O ₃ 1～8％，CaO45～65％，Fe ₂ O ₃ 1～8％，MgO0.01～4％，K ₂ O+Na ₂ 0.01 to 3 percent of O, 5 to 25 percent of C and 20 to 35 percent of loss on ignition; the waste stone powder in the step S11 is waste generated in the process of preparing the machine-made sand, and the main chemical components and the content are as follows: siO (SiO) ₂ 5～30％，Al ₂ O ₃ 1～8％，CaO45～65％，Fe ₂ O ₃ 1～6％，MgO3～8％，K ₂ O+Na ₂ 0.01 to 3 percent of O and 20 to 35 percent of loss on ignition; optionally, the effective CaO content in the powder 3 prepared in the step S11 is 68-72%, the MgO content is less than 3%, the digestion temperature is 66-70 ℃, the digestion time is 10-14 min, and the square-hole sieve is 0.08The rest is 9-13%, which meets the requirements of ASTMC5-2010 standard Specification of quicklime for construction.

10. The method for preparing a composite cementitious material according to claim 9, wherein the main chemical components and contents of the fluorogypsum in step S12 are: caO 35-40%, siO ₂ 0.2～6％，Al ₂ O ₃ 0.2～4％，MgO0.1～1％，SO ₃ 35～50％，CaF ₂ 2-8%; optionally, the main chemical components and contents of the desulfurized gypsum in the step S12 are as follows: SO (SO) ₃ 30～55％，CaO20～45％，SiO ₂ 2～4％，P ₂ O ₅ 1～3.5％，MgO0.01～2.5％，Na ₂ O0.01～1.5％，Fe ₂ O ₃ 0.01～6％，K ₂ 0.01 to 1.5 percent of O, 15 to 30 percent of loss on ignition and 0.01 to 1 percent of other components.