CN111718136A

CN111718136A - Method for producing silicate clinker by using coal gangue to replace tail coal and silicon-aluminum raw material

Info

Publication number: CN111718136A
Application number: CN202010619085.7A
Authority: CN
Inventors: 尹小林; 张新策
Original assignee: Changsha Zichen Technology Development Co Ltd
Current assignee: Changsha Zichen Technology Development Co Ltd
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2020-09-29

Abstract

A method for producing silicate clinker by using coal gangue to replace tail coal and a silicon-aluminum raw material comprises the following steps: (1) preparing powder from two components; (2) preheating, mixing and decomposing; (3) and (4) oxidizing and calcining. The invention can solve the problems that the quality of clinker production and energy consumption are influenced by crusting and blocking caused by the characteristics of raw coal gangue, a large amount of raw coal gangue is consumed to simultaneously replace partial tail coal and silica-alumina raw materials in dry cement production, the coal consumption in cement production and the consumption of the silica-alumina raw materials such as clay (shale) are reduced, and the problem of environmental pollution caused by coal gangue accumulation is solved.

Description

Method for producing silicate clinker by using coal gangue to replace tail coal and silicon-aluminum raw material

Technical Field

The invention relates to a production method of silicate cement clinker, in particular to a method for producing silicate clinker by using coal gangue to replace partial tail coal and a silicon-aluminum raw material.

Background

The coal gangue is a black-gray gangue mineral formed by mixing organic compounds and inorganic compounds deposited with coal in the process of moving crust into coal, and is a coal sedimentary rock containing combustible materials and mixed in a coal seam or the top or bottom plate or interlayer of a coal layer. Coal gangue exists in places with coal, and the coal gangue is solid waste generated in the processes of coal mining and washing, and comprises six types of rock gangues, coal gangues, natural gangues, washed gangues, hand-selected gangues and stripped gangues. The coal gangue can be classified into three categories according to the source of the coal gangue: the first type is tunneling gangue, namely, rock discharged in the tunneling process of a shaft, an underground parking lot, a main roadway, a coal mine normal production stage and the like in the mine construction period approximately accounts for 60 to 70 percent of the total amount of coal gangue; the second kind is coal gangue, namely coal gangue produced in the coal mining process, which approximately accounts for 10 to 30 percent of the total amount of the coal gangue; the third category is gangue washing, i.e. the residue discharged in coal washing process is about 10% of the total amount of coal gangue.

Currently, the classification of the types of the utilization of the existing coal gangue resources in China can be roughly divided into the following three major categories:

the first type is the white gangue (stone) which is discharged during strip coal mining stripping and underground roadway excavation, and is characterized by low carbon content, low heat value mostly, fluctuation of the heat value of the white gangue mostly being 100-1200 Kcal multiplied by 4.18KJ/Kg, and more mineral components, and deep development and utilization such as aluminum extraction, iron selection, heat preservation or refractory material preparation and the like are implemented according to different mineral components.

The second kind is gangue (stone) which is selected from coal gangue in the coal mining/coal washing process, the coal content of the gangue is high, the fluctuation of the heat value and the components is large, the fluctuation of the heat value of the gangue is mostly 500-2800 Kcal multiplied by 4.18KJ/Kg, and the gangue can be selected and utilized in different categories, such as the gangue with high heat value is used for industrial kilns, the backfill with low heat value, road building and the like.

The third kind is mature gangue (coal), which is obtained by roasting or heap-combustion heat treatment of coal gangue to remove most of combustible substances, and the heat value of the mature gangue mostly fluctuates between 0 and 200Kcal multiplied by 4.18KJ/Kg, and is mostly used for manufacturing building materials or chemical products. The white gangue and the gangue after being thermally treated are also collectively called as the primary gangue.

And secondly, screening sandstone gangue from the white gangue and the gangue for resource utilization in raw material ingredients in cement production, wherein the calorific value of the blocky sandstone gangue screened from the gangue is equivalent to that of the mature gangue (< 200 multiplied by 4.18 KJ/Kg).

In addition, it is classified according to the main mineral components and main chemical components of coal gangue. The coal gangue is generally classified into clay rock type coal gangue, sandstone type coal gangue and carbonate rock type coal gangue according to the main mineral structure classification of the coal gangue. According to the classification of main chemical components, the main chemical component of the coal gangue is SiO₂And A1₂O₃And the like, which can be divided into siliceous coal gangue, aluminum coal gangue and the like according to the relative content of chemical components. And low-sulfur coal gangue, high-sulfur coal gangue and the like according to the sulfur content in the coal gangue (the high-sulfur coal gangue is used for selecting pyrite or roasting to obtain SO)₂Practice for producing ammonium sulfate).

The nature of the coal gangue is that gangue is sandwiched between coal layers, the coal sedimentary rock waste separated during mining and washing is actually a mixture of carbonaceous shale/carbonaceous clay, carbonaceous sandstone, or carbonaceous carbonate rock and the like with other shale/clay, sandstone, conglomerate rock and the like. Along with the difference of geological age, region, mining condition and mining method of coal seam, the coal gangue composition and its mass fraction are different, i.e. the mineral composition, chemical composition and industrial analysis (ash, internal water, fixed carbon, volatile matter and calorific value) are different greatly, especially the fluctuation of the low calorific value of the coal gangue can be from 100 x 4.18KJ/Kg to 3000 x 4.18KJ/Kg, and the unit difference can reach tens of times. The calorific value difference of coal gangue of different batches in the same production place can also be several times.

From the mineral composition of the coal gangue, the coal gangue in different types has larger difference and certain characteristics.

The clay rock gangue is rich in a large amount of harmful trace elements due to the inherent adsorbability of clay minerals. The main mineral components of the clay rock type coal gangue are clay minerals (kaolinite, illite, montmorillonite, feldspar and boehmite), and minerals such as quartz, feldspar, calcite, mica, pyrite, carbonate and the like, and the clay rock type coal gangue also contains rich phytolith, organic matters, carbon and the like. Most of the materials are in a plate-shaped, layered or fiber structure, have certain hardness and high water permeability, are not easily influenced by groundwater, and are easily crushed in the processing process.

Sandstone gangue mainly contains quartz, mica, feldspar, phytolith, siderite nodule, etc., and clay mineral containing carbonate (kaolinite, illite, montmorillonite, feldspar), other inorganic salts, organic matters, carbon, etc. As for the so-called siliceous gangue, it is objectively a sandstone gangue having a high silica content.

The main mineral compositions of the carbonate gangue are calcite, dolomite and siderite, and secondly, more clay minerals (kaolinite, illite, montmorillonite and boehmite), terrestrial clastic minerals, carbonaceous and organic matters (including organic sulfur), pyrite and the like are mixed.

The main mineral composition of the aluminum rock gangue is high aluminum mineral such as gibbsite, boehmite, diaspore and the like, and the secondary mineral composition is clay mineral such as quartz chalcedony, limonite, muscovite, calcite, kaolin, feldspar, montmorillonite and the like, carbon, organic matter and the like.

In general terms, the coal gangue is made of clay [ kaolinite Al2O ]₃·2SiO₂·2H₂O, illite (Al, R)₂+)2[(Si,Al) Si₃O₁₀][OH]₂·nH₂O, montmorillonite (Na, Ca)0.33(Al, Mg)2[ Si ]₄O₁₀](OH)₂·nH₂O, muscovite (K. Al)₂)(AlSi₃O₁₀) (OH)₂Feldspar (KAlSi)₃O₈、NaAlSi₃O₈、CaAl₂Si₂O₈) Boehmite gamma-AlOOH, chlorite, sandstone (quartz SiO)₂) Carbonates [ calcite CaCO₃Dolomite (Ca. Mg) (CO)₃)₂Siderite FeCO₃Sulfide (pyrite FeS)₂) And bauxite (gibbsite, boehmite and diaspore), carbonaceous and organic matter as well as phytolithics, inorganic salts (chlorides, sulfates, phosphates) and small amounts of rare earthsMetal minerals and the like. The content of mineral components in the coal gangue in different regions, different sources and different categories is greatly different. For the application of coal gangue in cement production, it is worth noting that part of the coal gangue contains chlorite clay minerals which are difficult to be thermally decomposed.

From the chemical composition of the coal gangue, the main chemical component of the coal gangue is SiO₂、A1₂O₃、Fe₂O₃、CaO、MgO、Na₂O、K₂O、SO₃、P₂O₅、TiO₂And Loss on ignition (Loss on ignition), trace rare elements such as Ga, Sc, V, Li, Co, Sr and rare earth element Ce, etc., and combustible substances such as C (carbon), C_mH_nO (hydrocarbon oxygen nitrogen sulfur organic compound) and M_xS (sulfide). The content difference of chemical components of coal gangue in different regions, different sources and different categories is large, and the corresponding industrial analysis indexes (ash, internal water, fixed carbon, volatile matters and heat value) of the coal gangue are very different.

China is one of countries with abundant coal resource reserves, about 11.63% of the worldwide exploitable coal mining total reserves about 9842 million tons (about 1145 million tons in China), China is also a country with coal as a main energy source, according to statistical information issued by the national statistical bureau, the yield of raw coal in 2017 years in China is about 34.45 million tons, the comprehensive emission of coal gangue accounts for 15-20% of the yield of raw coal, a large amount of coal gangue is stacked in a waste discharge site after mining, occupies precious land resources, causes phenomena of underground infiltration, collapse and landslide of gangue hills, spontaneous combustion explosion and the like, and pollutes soil, underground water bodies and atmospheric environment. Beginning in the 60's 20 th century, the world began to develop comprehensive utilization research on coal gangue, and decades of years have seen the development of coal gangue as industrial kiln fuel or coal gangue for power generation, coal gangue brick firing, coal gangue calcination as cement admixture and raw material blending, low clinker/clinker-free cement production, concrete aggregate production, coal gangue microcrystalline glass, coal gangue mineral wool, silicon gangue production as silicon carbide porous ceramic material and mullite refractory material, aluminum hydroxide/alumina and aluminum chloride/polyaluminium chloride production from aluminum coal gangue, synthetic ammonium sulfate and other chemical products, extraction of high valence elements such as gallium scandium lithium vanadium cobalt and rare earth, preparation of molecular sieve, white carbon black, carbon black and superfine kaolin from calcined coal gangue, utilization of coal gangue as roadbed material, field reclamation and filling goaf/coal mine subsidence area, development of coal gangue, and development of coal gangue, The utilization of coal gangue for treating acid mine water, producing organic fertilizer and other industries/fields obtains huge achievements or remarkable success, but the waste discharge and accumulation quantity of the coal gangue is continuously increased at the speed of more than 6 hundred million tons per year, and at present, the accumulated accumulation and release quantity of the coal gangue is more than 45 hundred million tons, and the large-scale coal gangue mountain reaches 2600 seats. The application industries/fields of the coal gangue have objective limitations on the quality requirements, the economical efficiency, the environmental protection problems and the like of the coal gangue and the consumption of the coal gangue.

On the other hand, China is the largest cement energy-producing country in the world, and the cement production has huge consumption on nonrenewable resources of clay aluminosilicate raw materials and fire coal. Under the excitation of national policy, the technical personnel in the mass cement production field in China are always in diligent exploration practice, and almost all cement production scientific research institutions in China organize the development and research of special subjects of coal gangue utilization, for example, CN106277865B discloses a preparation method of portland cement clinker, CN104926163B discloses portland cement clinker and a preparation method thereof, and the coal gangue is used for producing portland cement clinker by blending coal gangue (the blending amount is 3-5%) in a specific chemical component range of low volatile matter (Vad 3-5.5%), high fixed carbon (FCad 8-10%), low moisture (Mad 0.2-0.35%) and low calorific value (100-800 Kcal/Kg) in a blending manner The method for preparing the material comprises the following key points: firstly, selecting coal gangue with low volatile matter, high fixed carbon, low moisture and low calorific value and specific chemical components, and controlling the doping amount within 5 percent so as to reduce the adverse effects of combustible matters, particularly volatile matters in the coal gangue, on the crusting, sticking and blocking of a kiln system and the like to the maximum extent; secondly, the decomposition rate of the raw materials entering the kiln is controlled to be 90-95% (the decomposition rate of the raw materials entering the kiln in the general dry cement production is controlled to be 97.5-99.5% so as to improve the productivity of the kiln system), so that the raw powder is used for reducing the crusting, sticking and blocking of a preheater and the kiln system, and the like. CN104986975B discloses a G-grade oil well cement and a processing technology thereof, the defects of the G-grade oil well cement are the same as the preparation method of the portland cement clinker disclosed in CN106277865B, the portland cement clinker disclosed in CN104926163B and the preparation method thereof, the requirements on the content of silicon and the like in coal gangue are higher, and the G-grade oil well cement has no reference significance on the batching requirements and the production of the portland cement clinker.

CN103833244B discloses an aeolian sand portland cement clinker and a production method thereof, wherein the production method comprises the following steps: firstly, directly mixing all raw materials including 7.82 to 5.42 parts of coal gangue, grinding and selecting powder to prepare raw material powder with the fineness of 10 to 12 percent; secondly, directly feeding the homogenized cold raw material powder into a decomposing furnace outside the rotary kiln for preheating and pre-decomposing; the third step is to send the biocatalysis product after preheating and predecomposition in a decomposing furnace into a rotary kiln for calcination, wherein the calcination temperature is 900-1450 ℃. The method is obviously different from the prior general dry cement production line in that a multi-stage preheater is used for preheating raw materials, and then the raw materials are put into a decomposing furnace for decomposing calcium carbonate in the raw materials, but the decomposing furnace is used for directly preheating cold raw material powder and carrying out pre-decomposition on the raw materials, namely, the decomposing furnace is used as a suspension roasting furnace (similar to fluidized bed roasting) containing coal gangue raw materials, and the combustible material containing raw materials are roasted by the decomposing furnace and then sent into a rotary kiln for calcination, so that the influence of the raw coal gangue on the working conditions of the normal dry cement production line preheater and a rotary kiln system is avoided.

CN110790525A discloses a preparation method of carbide slag cement containing coal gangue, CN107200486A discloses high-doped industrial waste slag cement and a preparation method thereof, which are processes for producing cement by mixing carbide slag, coal gangue, yellow waste slag and other series of industrial waste slag, and do not relate to the problem and the solution of influence of coal gangue mixing on the process control technology and the kiln condition of a dry-method cement production kiln system.

Known to those skilled in the art are: firstly, the decomposition temperature and the heat consumption of hydrated lime (the main component of carbide slag) are much lower than those of limestone, the normal heat consumption of cement clinker produced by replacing limestone with carbide slag dry powder is much lower, but the clinker heat consumption of the method is not lower than that of normal limestone batching, and the heat consumption is increased because of the instability of kiln conditions caused by serious skinning and blocking; secondly, the dry-process cement production line for preparing cement by carbide slag has serious crusting and blocking conditions and poor stability of a kiln system, so that the heat consumption of clinker is equivalent to or higher than that of normal limestone batching, and the addition of coal gangue batching is only serious in crusting and blocking.

CN104386930B discloses an application method of coal gangue in dry cement clinker production, which explores the influence of factors such as the doping mode, the doping amount, the grinding fineness and the like of the coal gangue in the production process of the dry cement clinker on the production process and thermal equipment through technical means such as experimental research (ingredient design, burnability test, coal gangue burnout test and industrial analysis) and CFD simulation analysis, and provides two modes of using the coal gangue as raw ingredient and using the coal gangue and coal dust as mixed fuel to be sprayed into a decomposing furnace. The usage mode of the coal gangue is used for blending, the coal gangue with specific quality requirements is prompted to be selected, and the blending rate of the coal gangue can be 9 percent or less than 9 percent according to the content of the main chemical components of the coal gangue, namely silicon, aluminum, iron, calcium and the theoretical chemical component rate. In the range of satisfying the target value of the blending (KH =0.91 + -0.02, SM =2.6 + -0.01, IM =1.6 + -0.01), 4.5855% can be blended theoretically when the coal gangue is used with the low-silica sandstone, and the temperature parameters of key parts need to be strictly controlled in the actual operation to prevent the system from generating crusting and blocking, but no effective technical control measure exists in the objective and actual conditions due to the characteristics of coal slamming. The mode that the coal gangue mixed fuel is fed into the decomposing furnace is used, and the theoretical analysis that the maximum usage amount of the coal gangue is 10% and less than 10% of the fuel fed into the decomposing furnace (namely the usage amount of the coal gangue is less than 0.007838kg/kg. cl and is only one tenth of the theoretical calculation value usage amount in raw materials) is prompted, otherwise, the combustion performance of the fuel fed into the decomposing furnace is seriously influenced (the combustion performance of the decomposing furnace is deteriorated, the furnace condition is deteriorated, and further the severe crusting and sticking blockage are caused to seriously influence the working condition of a kiln system).

In addition, the utilization mode of the coal gangue disclosed in CN104386930B, namely, the coal gangue is mixed with raw material ingredients and used as a decomposing furnace to replace fuel, is also two coal gangue utilization methods repeatedly explored and practiced by a large number of technical workers in the field of cement industry for decades, and although the workers in the field consider that the coal gangue can replace the silico-aluminum raw material and fuel for producing cement clinker, no feasible and effective method for solving the problem of influence of the coal gangue on the working condition of a cement kiln system is found up to now due to the characteristics of the coal gangue.

For decades, coal gangue has been used as a fuel for cement production. The raw material is also used as a raw material ingredient, and objectively becomes the chicken rib of a production enterprise in the cement industry. In order to solve the negative influence of direct blending of coal gangue on the working condition of a kiln system of a dry-process cement production line, a great deal of exploration practice is carried out by technical workers, and relatively effective technical measures can be roughly summarized into the following four technical schemes:

the method comprises the following steps: the method strictly limits the components, indexes and calorific values of coal gangue entering a factory, controls the dosage (mostly selects low calorific value coal gangue or sandstone basically without calorific values screened from the coal gangue), and enhances the homogenization of the coal gangue, for example, CN110845195A filed in 2019 in 12 months discloses a preparation method for producing portland cement clinker by the coal gangue, introduces a cement finial liability company for coke work of enterprises under Henan coking coal group, inherits social responsibility, adopts 0-3% of low calorific value coal gangue (massive sandstone basically without calorific values screened from the coal gangue) to directly carry out raw material blending through long-term exploration practice, so as to prevent the serious skin formation phenomenon generated by blending the coal gangue and stabilize the working condition of a kiln system.

A second method; oxygen-enriched combustion is adopted on the premise of controlling the calorific value and the consumption of coal gangue entering a factory so as to improve the working condition of a kiln system (see the text of technical and economic analysis for producing cement by oxygen-enriched air combustion-supporting coal gangue, published in the book of cement of Sichuan (1996 No. 3)). Besides the doubt of economy in the actual production, the method is not optimistic to solve the problem of skinning and blocking of a kiln system.

The third method comprises the following steps: the coal gangue is separated by adopting a special crushing, screening and separating mode, combustible powder in the coal gangue is separated and is mixed with the coal and then enters a kiln, and the gangue material after the combustible is basically removed is reused for raw material blending, for example, CN207086075U discloses a cement production system utilizing the coal gangue.

The method four comprises the following steps: the blending method after curing the coal gangue comprises the steps of firstly roasting or heap-burning the coal gangue to remove most or all combustible substances, simultaneously removing sulfides (pyrite) in the coal gangue through thermal decomposition, and then adding the roasted coal gangue (i.e. the cured coal gangue) into raw material blending, for example, a system for processing the coal gangue into a cement dry powder raw material and a processing method thereof disclosed in CN 108328951A. The method has large investment or occupies a field, wastes heat energy in the coal gangue and generates environmental pollution.

In summary, the existing method for utilizing raw coal gangue as resources in the dry-method cement production line is objectively not beneficial to large-scale consumption of gangue waste residues by cement enterprises due to the restriction of the problems of crusting, sticking, blocking and the like caused by the characteristics of gangue, and if the cement industry needs to realize the purpose of utilizing the raw coal gangue in a large amount and simultaneously replace part or all of the silica-alumina raw materials and part of the fuels produced by the dry-method cement production line, a new method for improving the characteristics of the raw coal gangue and enabling the raw coal gangue to be suitable for the equipment system characteristics of the dry-method cement production line is.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects in the prior art, and provide a method for producing silicate clinker by replacing part of tail coal and silica-alumina raw materials with coal gangue, which can replace part of tail coal and silica-alumina raw materials in dry cement production while consuming a large amount of raw coal gangue, reduce the consumption of fire coal in cement production and the consumption of the silica-alumina raw materials such as clay (shale), and solve the problem of environmental pollution caused by coal gangue accumulation. The method can effectively solve the problems that the clinker production quality, energy consumption and the like are influenced by the crusting and blocking caused by the characteristics of the raw coal gangue.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for producing silicate clinker by using coal gangue to replace tail coal and a silicon-aluminum raw material comprises the following steps:

(1) preparing powder from two components: adding a modified sintering aid into the coal gangue, mixing and grinding the coal gangue, and modifying the coal gangue to prepare coal gangue powder; mixing and grinding a calcareous raw material, a silicoaluminous raw material, a siliceous correcting material, an aluminous correcting material and an iron correcting material into raw material powder;

(2) preheating, mixing and decomposing: continuously feeding the coal gangue powder and the raw material powder obtained in the step (1) into a preheater of a dry-process cement clinker production line respectively according to the mass ratio of 3-20: 97-80 for preheating and mixing, feeding the mixture into a decomposing furnace for decomposition, adjusting the fluctuation specific condition according to the actual heat value of the coal gangue powder or the dosage proportion according to the instant fluctuation state of the outlet temperature of the decomposing furnace, adding or subtracting the dosage of tail coal dynamically, and feeding the decomposed mixed raw material powder into a rotary kiln of the dry-process cement clinker production line;

(3) oxidative calcination: and (3) adjusting the oxidizing atmosphere in the rotary kiln controlled by air to calcine the material fed into the rotary kiln in the step (2) to obtain silicate clinker.

The invention mixes and grinds coal gangue, calcium material, silicon-aluminum material, silicon correcting material, aluminum correcting material and iron correcting material respectively to prepare bi-component material powder. Because most of the mineral substances and chemical components of the coal gangue change greatly, the coal gangue can not be homogenized and changed in actual operation, and the components and the heat value of the coal gangue powder objectively fluctuate; the normal calcareous raw materials, the aluminosilicous raw materials, the siliceous correcting materials, the aluminous correcting materials, the ferruginous correcting materials and the like in the dry cement production are easy to homogenize, the raw material powder prepared by grinding the ingredients can be well homogenized and stabilized, the normal dry cement production has high control requirement on the stability of raw materials entering a kiln system, and the raw material powder is relatively stable in component.

Further, in the step (1), the coal gangue is raw coal gangue, and comprises various white gangue with low calorific value of 100 multiplied by 4.18 KJ/Kg-2800 multiplied by 4.18KJ/Kg, clay rock coal gangue with selected gangue, sandstone coal gangue (siliceous rock coal gangue), carbonate coal gangue and aluminous rock coal gangue.

Further, in the step (1), the modified sintering aid is added into the coal gangue, and the mass of the modified sintering aid is less than or equal to 3% of that of the coal gangue; the preferable dosage is 0.3-2%. So as to adapt to coal gangue with different mineral characteristics.

Further, in the step (1), the modified sintering aid is a mixture of an oxidant and one or two of silica gel and aluminum gel; when the content of alkali and sulfur in the coal gangue is low, the volatile matter is also low and is not enough to produce strong reduction action, and the coal gangue does not contain chlorite mineral, the modified sintering aid is not added. The modified combustion aid is added to inhibit the reduction of carbon organic matters in the coal gangue on iron oxides, sulfides and the like in raw material powder including coal gangue powder, absorb alkali sulfur volatilized from thermal decomposition of the cured coal gangue, promote the coal gangue to be quickly burnt out in smokeless suspension combustion of a decomposition furnace, and accelerate the pyrolysis of chlorite minerals.

Further, the oxidant is ferrate or permanganate or their mixture.

Further, in the step (1), the fineness of the coal gangue powder is 80 μm, and the screen residue is less than or equal to 18%. So as to ensure that the internal water and the combined water can be quickly preheated, expanded and removed and the energy consumption of the powder grinding is saved.

Further, in the step (1), the fineness of the raw material powder is 80 mu m, and the screen residue is less than or equal to 27%. So as to adapt to the easy burning property of raw materials and save the energy consumption of grinding.

According to the invention, a proper amount of modified combustion improver is added into the coal gangue to prepare coal gangue powder, so that a large amount of raw coal gangue can be consumed; the raw material powder is prepared by mixing and grinding the calcareous raw material, the silico-aluminous raw material, the silicon correcting material, the aluminum correcting material and the iron correcting material, breaks through the very mature and solidified preparation concept of the raw material, breaks through the basic idea of stable control of three rate values, and adopts a method of containing interval range fluctuation caused by the fluctuation of coal gangue components or the adjustment of dosage proportion by using the stable main body of the raw material. According to the fact that a cement production kiln is a high-temperature thermochemical reaction kiln system, on the premise that the clinker firing quality and the normal working condition of the kiln system are guaranteed, the large interval fluctuation range of the components of reaction materials can be controlled, and a three-rate value interval fluctuation control method is adopted.

Further, in the step (1), according to the actual conditions of the coal gangue, the siliceous correction material, the aluminous correction material, the ferrous correction material, the silicoaluminous raw material and the calcareous raw material (limestone and the like), the three rate values are controlled by selecting proper interval rate values in the ranges of lime saturation coefficient KH = 0.86-0.98, silicic acid rate SM = 2.2-3.2 and aluminum oxygen rate IM = 1.3-1.9, wherein:

KH＝(CaO-1.65Al₂O₃-0.35Fe₂O₃-0.7AO₃)/2.8SiO₂；

SM＝SiO₂/(Al₂O₃+Fe₂O₃)；

IM＝Al₂O₃/Fe₂O₃。

further, in the step (1), when the main chemical component SiO of the coal gangue is SiO₂、A1₂O₃、Fe₂O₃When CaO and MgO are relatively stable or are easy to be homogenized and stable, a process of respectively feeding bi-component powder into a preheater is adopted, and a three-rate value interval fluctuation control method calculated according to chemical components can be converted into a normal stable raw clinker three-rate value control mode in dry cement production.

Further, in the step (2), when the preheater system of the dry cement clinker production line is a five-stage cyclone preheater, the gangue powder obtained in the step (1) is metered and continuously fed into an upstream air pipe of a C5 cyclone preheater of the five-stage preheater system of the dry cement production line; continuously metering the raw meal powder obtained in the step (1), feeding the raw meal powder from an upstream air pipe of a C2 cyclone preheater, drawing the raw meal powder into a C1 cyclone preheater along with air, then unloading the raw meal powder into an upstream air pipe of a C3 cyclone preheater to draw a C2 cyclone preheater, then unloading the raw meal powder into an upstream air pipe of a C4 cyclone preheater from a C2 cyclone preheater to draw a C3 cyclone preheater along with air, and then unloading the raw meal powder into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw material powder which is distilled from a cone part of a C3 cyclone preheater, the coal gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters a C4 cyclone preheater along with wind, and is mixed with the raw material powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw material powder; the preheated mixed raw material powder is sent into a decomposing furnace through a cone-shaped distillation pipe of a C4 cyclone preheater, the pre-decomposed mixed raw material powder in the decomposing furnace enters a C5 cyclone preheater along with the drawing air, and enters a smoke chamber through a cone-shaped distillation pipe of a C5 cyclone preheater and is sent into a rotary kiln.

The gangue powder is discharged into a decomposing furnace (taking about 8 seconds) to be suspended along with pulling wind after being rapidly mixed and preheated by an upstream air pipe of a C5 cyclone preheater, a C4 cyclone preheater, hot raw meal powder and hot air flow, namely the gangue powder is rapidly heated to 680-780 ℃ from normal temperature and cold state in the powder environment in an anoxic upstream air pipe of a C5 cyclone preheater and a C4 cyclone preheater, rapidly passes through the volatilization and cracking temperature (350-600 ℃) section of carbon-containing organic matters and sulfides in the gangue, only internal water and combination water which obstruct heating and ignition combustion are obtained and removed in the gangue, the rapid oxidation combustion temperature range of combustible matters such as carbon organic matters in the gangue (680-800 ℃ and dehydration and expansion) is achieved, and the combustion performance of the rapidly preheated gangue powder particles suspended in a straight-tube decomposing furnace along with pulling wind is greatly superior to that anthracite powder or semi-bituminous coal powder which enters the decomposing furnace in a cold state (the cold state needs to be heated first, and then is rapidly preheated along with hot air, The constant temperature dehydration section removes the internal water and the combined water, and the coal can be burnt only in the time period of temperature rise), and the modified combustion assistant agent has the modified combustion assisting effect on the coal gangue powder particles, so that the combustible substances in the coal gangue can be quickly burnt out in a decomposition furnace in a smokeless suspension combustion mode, and the released heat is directly supplied for the decomposition of calcium carbonate, thereby achieving the effect of effectively replacing the tail coal. The aluminosilicate minerals in the coal gangue are completely decomposed into active oxides in a decomposing furnace, and a small amount of chlorite minerals are also disintegrated into the active oxides under the synergistic action of the modified sintering aid (the decomposition temperature of the aluminosilicate minerals in the coal gangue is generally 580-820 ℃, the aluminosilicate minerals do not have enough decomposition time in a C4 cyclone preheater, and the decomposition temperature of chlorite is 1050-1175 ℃). The sulfide (such as pyrite) in the coal gangue is oxidized and decomposed into SO in a decomposing furnace₂/SO₃、Fe₂O₃Etc. (insufficient decomposition time in the C4 cyclone preheater), SO in a non-reducing atmosphere in the decomposing furnace₂/SO₃Combining with the newly generated high-activity CaO to generate calcium sulfate and fixing. The coal gangue mixed raw material powder pre-decomposed in the decomposing furnace enters a C5 cyclone preheater along with the drawing wind, enters a smoke chamber through a fractionating pipe at the cone part of the C5 cyclone preheater and is sent into a rotary kiln, and the coal gangue becomes a silicon-aluminum raw material of silicate clinker produced by dry cement.

The invention directly solves the problems that the carbonaceous combustible materials, alkali sulfur and the like in the coal gangue are gradually heated up and volatilized/reduced and decomposed in the C1, C2, C3 and C4 grade preheaters of a multi-grade preheater, the reducibility and reducibility materials of raw materials are gradually increased, the reducibility atmosphere in a decomposing furnace is further increased, the reducibility skinning and blocking in the C5 grade preheater, a kiln tail smoke chamber and a rotary kiln are further increased in a linkage manner, the kiln condition, the energy consumption and the production quality of the dry cement production are further seriously influenced (the reduction reaction absorbs heat, the skinning and blocking and the treatment thereof increase the heat consumption), and the problem that the pollution control of the hydrocarbon and the sulfur dioxide caused by the application of the coal gangue.

Further, in the step (2), when the preheater system of the dry cement clinker production line is a six-stage cyclone preheater, the gangue powder obtained in the step (1) is metered and continuously fed into an upstream air pipe of a C6 cyclone preheater of the six-stage preheater system of the dry cement production line; raw material powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, is discharged into an upstream air pipe of a C5 cyclone preheater to be pulled into a C4 cyclone preheater along with air, and is discharged into an upstream air pipe of a C6 cyclone preheater from a C4 cyclone preheater to be pulled into a C5 cyclone preheater along with air; after being continuously mixed with raw meal powder which is distilled from a cone part of the C4 cyclone preheater, the gangue powder fed into an ascending air pipe of the C6 cyclone preheater enters the C5 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C6 cyclone preheater and the C5 cyclone preheater to form mixed raw meal powder; the preheated mixed raw material powder is fed into a decomposing furnace through a cone-shaped distillation tube of a C6 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw material powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposition of calcium carbonate in the mixed raw material powder, inorganic minerals of the coal gangue are thermally decomposed into components of which active oxides are all raw material components, the pre-decomposed mixed raw material powder in the decomposing furnace enters a C6 cyclone preheater along with pulling air, and the mixed raw material powder enters a smoke chamber through the cone-shaped distillation tube of the C6 cyclone preheater and is fed into a rotary kiln.

Similarly, the gangue powder is discharged into the decomposing furnace after being rapidly mixed and preheated by the ascending air pipe of the C6 cyclone preheater, the C5 cyclone preheater, the hot raw material powder and the hot air flow (taking about 8 seconds) to suspend along with the pulling air, namely, the gangue powder is rapidly heated to 680-780 ℃ from the normal temperature cold state in the powder environment of the ascending air pipe of the anoxic C6 cyclone preheater and the C5 cyclone preheater, rapidly passes over the volatilization and cracking temperature (350-600 ℃) section of the carbon-containing organic matters in the gangue, and only obtains and removes the internal water and the combination water which obstruct the heating and the burning along with the fire in the gangue, thereby achieving the rapid oxidation burning temperature range (680-800 ℃) of the carbon-containing organic matters and the like in the gangue, and the combustion performance of the rapidly preheated (dehydrated and puffed) gangue powder particles suspending in the straight-tube decomposing furnace along with the pulling air is greatly superior to that the anthracite powder or semi-bituminous powder which enters the decomposing furnace in the cold state (the cold state needs to be heated, dehydrated, The constant temperature dehydration section removes the internal water and the combined water, and the coal can be burnt only in the time period of temperature rise), and the modified combustion assistant agent has the modified combustion assisting effect on the coal gangue powder particles, so that the combustible substances in the coal gangue can be quickly burnt out in a decomposition furnace in a smokeless suspension combustion mode, and the released heat is directly supplied for the decomposition of calcium carbonate, thereby achieving the effect of effectively replacing the tail coal. The aluminosilicate minerals in the coal gangue are completely decomposed into active oxides in a decomposing furnace, and a small amount of chlorite minerals are also disintegrated into the active oxides under the synergistic action of the modified sintering aid (the decomposition temperature of the aluminosilicate minerals in the coal gangue is generally 580-820 ℃, the aluminosilicate minerals do not have enough decomposition time in a C5 cyclone preheater, and the decomposition temperature of chlorite is 1050-1175 ℃). The sulfide (such as pyrite) in the coal gangue is oxidized and decomposed into SO in a decomposing furnace₂/SO₃、Fe₂O₃Etc. (insufficient decomposition time in the C5 cyclone preheater)SO in a non-reducing atmosphere in a decomposing furnace₂/SO₃Combining with the newly generated high-activity CaO to generate calcium sulfate and fixing. The coal gangue mixed raw material powder pre-decomposed in the decomposing furnace enters a C6 cyclone preheater along with the drawing wind, enters a smoke chamber through a fractionating pipe at the cone part of the C6 cyclone preheater and is sent into a rotary kiln, and the coal gangue becomes a silicon-aluminum raw material of silicate clinker produced by dry cement.

Further, in the step (2), the tail coal dosage is dynamically and timely increased or decreased according to the specific situation that the real heat value of the coal gangue powder or the dosage proportion adjusts fluctuation according to the instant fluctuation range of the outlet temperature of the decomposing furnace of 860-890 ℃, preferably 875 +/-10 ℃; when the heat value of the coal gangue is high or the dosage proportion is increased, the dosage of the tail coal is reduced when the temperature of the outlet of the decomposing furnace is increased, the heat value of the coal gangue is low or the dosage proportion is reduced, and the dosage of the tail coal is increased when the temperature of the outlet of the decomposing furnace is reduced.

Further, in the step (3), the oxidizing atmosphere calcination temperature is 1400 ℃ to 1500 ℃, preferably 1450 ℃.

In the actual operation, the invention controls two key links: firstly, the oxidizing atmosphere in the rotary kiln is regulated and controlled by wind to calcine, the firing quality of the clinker is stabilized by firing a strong kiln head with one fire, the firing quality of the clinker is stable, the fluctuation of the mineral composition three-rate value of the clinker in a certain interval range caused by the fluctuation of coal gangue components has the influence on the physical and mechanical performance indexes of silicate clinker and cement within a bearable range. And secondly, adding or subtracting the tail coal dosage immediately according to the instant fluctuation range of the outlet temperature of the decomposing furnace of 860-890 ℃. Because the gangue powder which is rapidly preheated to the combustion temperature (and the internal hydration water is removed) in the decomposing furnace is a tail coal fuel which is easy to burn out, when the heat value of the gangue is high, the furnace temperature rises, the feeding amount of the tail coal is timely reduced, and the tail coal is even stopped to feed, so that the excessive fuel is prevented (the carbon which is not timely burnt out by the excessive fuel can cause reduction, skinning and blocking of C5, a blanking distillation tube, a kiln tail smoke chamber and a necking), and if the heat value of the gangue is low, and the furnace temperature is reduced, the feeding amount of the tail coal is timely increased.

The invention has the following beneficial effects:

1) the dry method cement production line which can effectively utilize huge capacity and is widely distributed in China can be used for consuming various raw coal gangue on a large scale, including all various white gangue, clay rock gangue with gangue selection, sandstone gangue (siliceous rock gangue), carbonate rock gangue and aluminum rock gangue, the component fluctuation of the gangue is almost ignored, especially the heat value fluctuation of the gangue is ignored, the sulfur content of the gangue is also ignored, the low-order heat value of the gangue can be randomly used from 0-3000 multiplied by 4.18KJ/Kg, and as long as the heat energy released by completely burning the used gangue does not exceed the heat energy of tail coal normally used in the dry method cement production. The coal can replace 60 percent of fire coal in a dry cement production line (the tail coal in the dry cement production generally accounts for 60 percent of the total coal) to the maximum extent and replace all the raw material of the silica-alumina clay (shale). The method is expected to solve the problem of environmental pollution caused by coal gangue accumulation, save a large amount of fire coal for cement enterprises and greatly reduce the consumption of clay-like silicon-aluminum raw materials;

2) aiming at the characteristics of mature dry-method cement production line process equipment, the essence of firing of silicate clinker and the formation characteristics of physical and mechanical properties of silicate cementing material, the basic concepts of preparation of a very mature and cured raw material and stable control of a three-rate value are broken through, and according to the fact that a cement production kiln is a set of high-temperature thermochemical reaction kiln system, on the premise that the firing quality of clinker and the normal working condition of the kiln system are ensured, the fluctuation interval range of raw material components can be greatly widened and controlled, a bi-component powder making method and a three-rate value interval fluctuation control method are created, and the innovative development of cement production technology is favorably guided;

3) aiming at the characteristics of coal gangue and the characteristics of process equipment of a dry cement production line, the method simply and directly solves the problems that carbonaceous combustible substances, alkali, sulfur and the like in the coal gangue are gradually volatilized/reductively decomposed in a multi-stage preheater, the reducibility and reducibility materials of raw materials are gradually aggravated, the reducing atmosphere in a decomposing furnace is aggravated, the reducibility skinning and blocking in a C5 stage preheater, a kiln tail smoke chamber and a rotary kiln are aggravated in a linkage manner, and further the kiln condition, the energy consumption and the product quality of dry cement production are seriously influenced (the heat absorption of the reduction reaction, the skinning and blocking and the treatment thereof increase the heat consumption), and the problems that the pollution control of hydrocarbon volatile substances and sulfur dioxide is difficult due to. The method for modifying and treating the coal gangue, quickly preheating the coal gangue to the ignition point and removing water in the coal gangue and compound water which obstruct combustion effectively converts the coal gangue into an alternative fuel and a silicon-aluminum raw material which can be cleanly combusted, provides a brand new method for cement enterprises to utilize solid waste containing combustible substances/sulfur, and is beneficial to energy conservation and emission reduction, cost reduction and efficiency improvement of the cement enterprises.

Detailed Description

The present invention will be further described with reference to the following examples.

The chemical reagents used in the examples of the present invention, unless otherwise specified, are commercially available in a conventional manner.

The embodiment 1-3 is carried out on a certain phi 4.2 x 64m cement production line with a five-stage cyclone preheater precalcination kiln drying method, and the raw material ingredients for normal production are as follows: the method is characterized in that limestone serving as a calcareous raw material, waste clay/shale serving as a silico-aluminous raw material, sandstone serving as a siliceous correction material and pyrite cinder serving as an irony correction material are used as fire coal, the fire coal adopts semi-bituminous coal with 11-16% of volatile components and 5200-5600 Kcal/kg of heat value, and the clinker rate value is controlled to be KH =0.93 +/-0.02, SM =2.6 +/-0.1 and IM 1.6 +/-0.1. In the production, the ratio of the head coal to the tail coal of the coal for calcination is about 0.37 of the head coal to the tail coal, 0.63 of the tail coal, a kiln tail smoke chamber, a throat and a moderate crust in a kiln, a long ring and a stable kiln condition, and a small amount of glutinous rice dumpling yellow reducing material is mixed in the clinker. The average output of clinker under normal kiln conditions is 2756t/d, the actual standard coal consumption of the clinker is 116.9kg/t, the vertical lifting weight fluctuation of the clinker is 1163-1327 g/L, the f-CaO fluctuation is 0.7-1.8%, the phase fluctuation of the clinker is 23.1-27.4%, the clinker strength fluctuation is 24.7-32.1 MPa in 3d, 52.4-58.3 MPa in 28d, the water requirement fluctuation of standard consistency is 22.5-27.5%, the fluidity fluctuation is 162-187 mm, the coagulation time fluctuation is 93-137 min in initial coagulation and 125-173 min in final coagulation.

In each embodiment, the modified sintering aid is a Zc-R1 liquid sintering aid produced by the development Limited company of the little Yi in Hunan province, and the main component of the modified sintering aid is a liquid mixture of an oxidant ferrate solution and silica gel.

Example 1

In the embodiment, coal gangue is taken from a piled coal gangue mountain and is coal gangue mixed with white gangue and gangue selection, 100 coal gangue samples are taken according to a sampling routine for analysis, the appearance and analysis of the coal gangue samples show that the fluctuation range of the components of the coal gangue is very large, the fluctuation range of the water content (w) in the coal gangue is 0.2-5.2%, the fluctuation range of the external water content (w) is 4.3-11.6%, and the industrial analysis value fluctuates in that the ash content (Aad) is 59.7-91.3%, the volatile matter (Vad) is 2.6-21.4%, the water content (Mad) is 0.2-6.4%, the fixed carbon (FCad) is 1.1-18.3%, and the heat value (Qnet. ad) is 187-23 2373 × 4.18.18 kJ/kg., wherein the fluctuation range of the main chemical component (w) is SiO₂43.8～67.6%、A1₂O₃7.3～21.7%、Fe₂O₃3.4～9.1%、CaO 1.3～8.4% 、MgO 0.7～4.8%、K₂O 0.8～2.7%、Na₂O 0.6～1.8%、SO₃0.3～3.7%、P₂O₅0.00~0.16%、TiO₂0.00-0.71% and Loss on ignition (Loss) 6.7-27.3%.

Repeatedly analyzing and evaluating with a cement plant, and adopting a three-rate value interval fluctuation control method to draw up the gangue in the batch to replace 13.7% of waste soil shale of the alumino-silica raw material, wherein the clinker three-rate value is controlled by an interval range rate value with lime saturation coefficient KH = 0.90-0.97, silicic acid rate SM = 2.31-2.65 and alumina rate IM ═ 1.31-1.70.

In this embodiment, a mixed material of waste soil and shale is prepared by replacing part of the tail coal and the alumino-silica raw material with coal gangue, and the silicate clinker is produced by replacing part of the tail coal and the alumino-silica raw material with coal gangue according to the following steps:

(1) preparing powder from two components: adding the modified sintering aid which is 0.7 percent of the mass of the coal gangue into the coal gangue, mixing and grinding the coal gangue, and modifying the coal gangue to prepare coal gangue powder with the fineness of 80um and the surplus screen of 12 percent; mixing and grinding calcareous raw material limestone, siliceous correction material sandstone and ferrous correction material pyrite cinder into raw material powder with fineness of 80 mu m and screen residue of 16 percent;

(2) preheating, mixing and decomposing: respectively and continuously feeding the gangue powder obtained in the step (1) and the raw material powder into a preheater system according to the mass ratio of = 13.7-14.7: 86.3-85.3; the gangue powder is metered and continuously fed into an upstream air pipe of a C5 cyclone preheater of a five-stage preheater system of a dry cement production line; raw meal powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, and is discharged into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw meal powder which is distilled from a cone part of the C3 cyclone preheater, the gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters the C4 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw meal powder; the preheated mixed raw material powder is sent into a decomposing furnace through a conical distillation tube of a C4 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw material powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposing calcium carbonate in the mixed raw material powder, inorganic minerals of the coal gangue are thermally decomposed into active oxides which are all components of raw material components, and the use amount of tail coal is timely increased or decreased according to the fluctuation range of 860-880 ℃ of the outlet temperature of the decomposing furnace so as to ensure the decomposition rate; mixed raw meal powder pre-decomposed in the decomposing furnace enters a C5 cyclone preheater along with pulling air, enters a smoke chamber through a fractionating pipe at the cone part of the C5 cyclone preheater and is sent into a rotary kiln;

(3) oxidative calcination: calcining the material fed into the rotary kiln in the step (2) into silicate clinker (clinker firing temperature 1450 ℃) by adopting strong-firing kiln head with one fire and adjusting oxidizing atmosphere in the rotary kiln controlled by wind; in order to stabilize the firing quality of silicate clinker (aiming at the problems that the fuel adopted by the plant is semi-bituminous coal and actually is blended coal mainly comprising anthracite, the flame of a kiln head with poor combustion performance is burnt out and cut off, and the bituminous coal with good combustion performance is inconvenient to replace due to large stock coal quantity, the mature coal catalytic oxidation combustion method is adopted for the semi-bituminous coal fuel in the experimental stage to ensure that the kiln head is well fired, the tail coal consumption is dynamically and timely increased or decreased according to the fluctuation range of 870 +/-10 ℃ of the outlet temperature of a decomposing furnace and the fluctuation condition of the actual heat value of coal gangue powder, so as to prevent the excessive or insufficient fuel (the excessive fuel can not burn out carbon in time to cause reduction, skinning and sticking of C5, a blanking distillation tube, a kiln tail smoke chamber and a necking, and the insufficient fuel affects the furnace temperature and the kiln condition), the furnace temperature is increased (the heat value of coal gangue is high) to reduce the feeding amount of the tail coal, and the furnace temperature is decreased (the heat value of coal gangue is low) to increase the feeding amount of the tail coal.

To track the fluctuation of clinker quality, one round of clinker sample is taken every hour.

The test is continuously operated for 74.6 hours, the preheater, the kiln tail smoke chamber, the necking and the kiln are not obviously skinned and stuck, the kiln head is clear, no flying sand exists basically, the caking property of the clinker is good, no reducing material exists, the fluctuation of the vertical lifting weight of the clinker is 1257-1382 g/L, the fluctuation of f-CaO is 0.5-1.2%, and the operation condition of the kiln system is normal. The kiln tail exhaust emission has no negative influence, and the environmental protection on-line flue gas monitoring shows SO₂The emission value is slightly reduced, and the consumption of the denitrified ammonia water is also slightly reduced.

The head coal consumption of the coal for calcination is equivalent, the tail coal consumption reduction amplitude fluctuates between 32% and 74%, the average standard coal consumption of 3 days per ton of clinker is reduced to 83.6kg/t, and the standard coal consumption of per ton of clinker is reduced by 33.3 kg/t.

The clinker yield in 3 days is 2867t/d on average, and the yield is slightly increased.

The 3-day clinker sample analysis actual value fluctuation is lime saturation coefficient KH = 0.914-0.947, silicic acid rate SM = 2.29-2.48, and aluminum oxygen rate IM 1.36-1.57; the phase fluctuation of the cooked material liquid is 24.8-27.5%, the strength fluctuation of the cooked material is 28.4-34.7 MPa in 3d compressive strength and 57.3-64.7 MPa in 28d compressive strength, the water requirement fluctuation of the standard consistency is 22.8-26.5%, the fluidity fluctuation is 178-186 mm, the coagulation time fluctuation is 97-128 min in initial coagulation and 124-157 min in final coagulation. Namely, the quality stability of the clinker produced by adopting a three-rate value interval fluctuation control method is improved rather than the normal homogenization and stabilization three-rate value control method, and all physical and mechanical performance indexes of the clinker are improved.

The production test shows that the method for producing the silicate clinker by using the coal gangue to replace partial tailing coal and the silicon-aluminum raw material is feasible, and the mixed gangue accumulated in the coal gangue dump can save a large amount of tailing coal at one time, and the average saving of the tailing coal reaches 45.22%; and secondly, the clinker aggregate can replace a large amount of clay shale silicon-aluminum raw materials, can effectively solve the problem that the working condition of a kiln system is influenced by crusting and blocking caused by the characteristics of coal gangue, can improve the quality and the physical and mechanical properties of clinker, and has no negative influence on the emission of smoke.

Example 2

In the embodiment, the coal gangue is selected from gangue discarded in coal mining operation of coal mine, the gangue is directly transported to a factory from the coal mine, 40 coal gangue samples are taken according to a sampling routine for analysis, and the industrial analysis values of the coal gangue fluctuate within the range of 69.6-88.7% of ash (Aad), 4.6-17.3% of volatile matter (Vad), 1.0-4.7% of water (Mad), 2.8-15.3% of fixed carbon (FCad), 487-2253 × 4.18.18 kJ/kg. main chemical components (w) fluctuation range of SiO₂49.7～65.4%、A1₂O₃7.9～19.4%、Fe₂O₃3.3～8.4%、CaO 1.7～8.1% 、MgO 0.6～3.9%、K₂O 0.7～2.5%、Na₂O 0.4～1.5%、SO₃0.5～4.7%、P₂O₅0.00~0.13%、TiO₂0.00-0.56% and Loss on ignition (Loss) 8.2-29.1%. The coal gangue modified combustion improver for the test is provided by the development Limited company of the little Yi's environmental energy science and technology of Hunan province (liquor No. Zc-R1), and the main component of the coal gangue modified combustion improver is a liquid mixture of an oxidant, silica gel and aluminum gel.

Repeatedly analyzing and evaluating with a cement plant, and adopting a three-rate value interval fluctuation control method to draw up the gangue in the batch to replace 13.1 percent of alumino-silica raw material shale, wherein the clinker three-rate value is controlled and set to be in an interval range of values of lime saturation coefficient KH = 0.89-0.97, silicic acid rate SM = 2.35-2.75 and aluminum oxygen rate IM 1.32-1.62.

(1) preparing powder from two components: adding 0.4% modified sintering aid by mass into the coal gangue, mixing, grinding and modifying to prepare coal gangue powder with fineness of 80um and surplus screen of 10%; mixing and grinding the calcium raw material limestone, siliceous correction material sandstone and iron correction material pyrite cinder into raw material powder with fineness of 80um and residual sieve of 18 percent;

(2) preheating, mixing and decomposing: respectively and continuously metering the gangue powder obtained in the step (1) and raw meal powder according to the mass ratio of = 12.9-14.6: 87.1-85.4 and feeding the gangue powder and the raw meal powder into a preheater system; the gangue powder is metered and continuously fed into an upstream air pipe of a C5 cyclone preheater of a five-stage preheater system of a dry cement production line; raw meal powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, and is discharged into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw meal powder which is distilled from a cone part of the C3 cyclone preheater, the gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters the C4 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw meal powder; the preheated mixed raw meal powder is sent into a decomposing furnace through a conical distillation pipe of a C4 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw meal powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposing calcium carbonate in the mixed raw meal powder, and inorganic minerals of the coal gangue are thermally decomposed into active oxides which are all components of raw meal; adding and reducing the tail coal dosage in time according to the fluctuation range of 875 ℃ to 880 +/-10 ℃ of the outlet temperature of the decomposing furnace so as to ensure the decomposition rate; mixed raw meal powder pre-decomposed in the decomposing furnace enters a C5 cyclone preheater along with pulling air, enters a smoke chamber through a fractionating pipe at the cone part of the C5 cyclone preheater and is sent into a rotary kiln;

(3) oxidative calcination: calcining the materials in the rotary kiln into silicate clinker (clinker firing temperature 1450 ℃) by using strong firing kiln head and adjusting the oxidizing atmosphere in the rotary kiln controlled by wind; in order to stabilize the firing quality of silicate clinker (aiming at the problems that the fuel adopted by the plant is semi-bituminous coal and actually is blended coal mainly comprising anthracite, the burning performance of the kiln head flame is poor, the kiln head flame is cut off, and the bituminous coal with good burning performance is inconvenient to replace due to large stock coal quantity, the mature coal catalytic oxidation combustion method is adopted for the semi-bituminous coal fuel in the experimental stage to ensure that the kiln head is well fired, the tail coal consumption is dynamically and timely increased or decreased according to the fluctuation range of 875 +/-10 ℃ of the outlet temperature of the decomposing furnace and the fluctuation condition of the actual heat value of the coal gangue powder, so as to prevent the excessive or insufficient fuel (the excessive fuel can not burn out the carbon in time to cause the reduction, the crusting and the sticking of C5 and a blanking distillation tube, a kiln tail smoke chamber and a necking, and the insufficient fuel affects the furnace temperature and the kiln condition), the furnace temperature is increased (the heat value of the coal gangue is high), the feeding amount of the tail coal is reduced in time, and the feeding amount of the tail coal is increased in time when the furnace temperature is decreased (the heat value of the coal gangue is low).

The test is continuously operated for 72.6 hours, the preheater, the kiln tail smoke chamber, the necking and the kiln are not obviously skinned and stuck, the kiln head is clear, no flying sand exists basically, the caking property of the clinker is good, no reducing material exists, the fluctuation of the vertical lifting weight of the clinker is 1249-1381 g/L, the fluctuation of f-CaO is 0.4-1.0%, and the operation condition of the kiln system is normal. The kiln tail exhaust emission does not have any negative effect, and the environmental protection on-line flue gas monitoring shows that the SO2 emission value is slightly reduced, and the denitration ammonia water consumption is also slightly reduced.

The head coal consumption of the coal for calcination is equivalent, the tail coal consumption reduction amplitude fluctuates between 38% and 87%, the average standard coal consumption of 3 days per ton of clinker is reduced to 76.3kg/t, and the standard coal consumption of per ton of clinker is reduced by 40.6 kg/t.

The clinker yield in 3 days is 2865t/d on average, and the yield is slightly increased.

The analytical actual value fluctuation of the clinker sample in 3 days is lime saturation coefficient KH = 0.901-0.958, silicic acid rate SM = 2.32-2.63, and alumina rate IM 1.34-1.59; the clinker phase fluctuation is 23.8-26.3%, the clinker strength fluctuation is 28.2-36.2 MPa in 3d compressive strength and 57.9-68.3 MPa in 28d compressive strength, the water requirement fluctuation of standard consistency is 22.4-26.3%, the fluidity fluctuation is 180-186 mm, the setting time fluctuation is 107-132 min in initial setting and 136-154 min in final setting. Namely, the quality stability of the clinker produced by adopting a three-rate value interval fluctuation control method is improved rather than the normal homogenization and stabilization three-rate value control method, and all physical and mechanical performance indexes of the clinker are improved.

The production test shows that the method for producing the silicate clinker by using the coal gangue to replace partial tailing coal and the silicon-aluminum raw material is feasible, and the mixed gangue accumulating the coal gangue dump can save a large amount of tailing coal at one time, and the average saving of the tailing coal reaches 55.13 percent; and secondly, the clinker aggregate can replace a large amount of clay shale silicon-aluminum raw materials, can effectively solve the problem that the working condition of a kiln system is influenced by crusting and blocking caused by the characteristics of coal gangue, can improve the quality and the physical and mechanical properties of clinker, and has no negative influence on the emission of smoke.

Example 3

The coal gangue in the embodiment is selected from the washed gangue of a certain coal washing plant, is directly transported to a site from the coal washing plant, 38 coal gangue samples are taken according to a sampling routine for analysis, and the industrial analysis values of the coal gangue samples fluctuate within the range that ash (Aad) is 71.3-89.7%, volatile matter (Vad) is 3.7-16.4%, moisture (Mad) is 0.94-5.3%, fixed carbon (FCad) is 2.9-12.6%, and calorific value (Qnet. ad) is 287-1427 × 4.18.18 kJ/kg. main chemical components (w) fluctuate within the range of SiO 7₂47.9～65.3%、Al₂O₃6.8～18.2%、Fe₂O₃3.7～8.7%、CaO 1.6～8.4%、MgO 1.4～4.8%、K₂O 0.8～2.1%、Na₂O 0.5～1.4%、SO₃1.6～3.7%、P₂O₅0.00~0.13%、TiO₂0.00-0.57% and Loss on ignition (Loss) 6.5-25.3%. The coal gangue modified combustion improver for the test is provided by the development Limited company of the little Yi's unconformable environmental energy science and technology in Hunan province (liquid No. Zc-R), and the main component is a liquid mixture of an oxidant and alumina gel.

Repeatedly analyzing and evaluating with a cement plant, and adopting a three-rate value interval fluctuation control method to draw up the gangue in the batch to replace 13.1 percent of alumino-silica raw material shale, wherein the clinker three-rate value is controlled and set to be in an interval range of values of lime saturation coefficient KH = 0.91-0.98, silicic acid rate SM = 2.35-2.85 and aluminum oxygen rate IM 1.25-1.65.

(1) preparing powder from two components: adding 0.9% of modified sintering aid by mass into the coal gangue, mixing, grinding and modifying to prepare coal gangue powder with fineness of 80um and 8% of screen residue; mixing and grinding the calcium raw material limestone, siliceous correction material sandstone and iron correction material pyrite cinder into raw material powder with fineness of 80um and screen residue of 16 percent;

(2) preheating, mixing and decomposing: respectively and continuously feeding the gangue powder obtained in the step (1) and the raw material powder into a preheater system according to the mass ratio of = 12.8-14.2: 87.2-85.8); continuously feeding coal gangue powder into an upstream pipe of a C5 cyclone preheater of a five-stage preheater system of a dry cement production line through metering; raw meal powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, and is discharged into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw meal powder which is distilled from a cone part of the C3 cyclone preheater, the gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters the C4 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw meal powder; the preheated mixed raw meal powder is sent into a decomposing furnace through a conical distillation pipe of a C4 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw meal powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposing calcium carbonate in the mixed raw meal powder, and inorganic minerals of the coal gangue are thermally decomposed into active oxides which are all components of raw meal; adding and reducing the tail coal dosage in time according to the fluctuation range of 870 +/-5 ℃ at the outlet temperature of the decomposing furnace to ensure the decomposition rate; the mixed raw meal pre-decomposed in the decomposing furnace enters the C5 cyclone preheater along with the drawing air, and enters the smoke chamber through the fractionating pipe at the cone part of the C5 cyclone preheater and is sent into the rotary kiln.

(3) Adjusting the use amount of tail coal, oxidizing and calcining: calcining the materials in the rotary kiln into silicate clinker (clinker firing temperature 1450 ℃) by using strong firing kiln head and adjusting the oxidizing atmosphere in the rotary kiln controlled by wind; in order to stabilize the firing quality of silicate clinker (aiming at the problems that the fuel adopted by the plant is semi-bituminous coal, actually is blended coal mainly comprising anthracite, the burning performance of the kiln head is poor, the flame is burnt out and cut off, and the bituminous coal with good burning performance is inconvenient to replace due to large coal inventory, the semi-bituminous coal fuel adopts a mature coal catalytic oxidation burning method to ensure that the kiln head is burnt one fire); according to the fluctuation range of 870 +/-5 ℃ of the outlet temperature of the decomposing furnace and the condition of fluctuation of the actual heat value of the coal gangue powder, the amount of the tail coal is dynamically and timely increased or decreased so as to prevent excessive fuel or insufficient fuel (carbon which is not timely burnt out of the excessive fuel can cause reduction, skinning, sticking and blocking of C5, a discharging distillation tube, a kiln tail smoke chamber and a throat and influence the furnace temperature and the kiln condition due to insufficient fuel), timely reduce the feeding amount of the tail coal when the furnace temperature rises (the heat value of the coal gangue is high), and increase the feeding amount of the tail coal when the furnace temperature falls (the heat value of the coal gangue is low).

The test is continuously operated for 73 hours, the phenomena of obvious skinning, sticking and blocking do not occur in the preheater, a kiln tail smoke chamber, a throat and a kiln, the kiln head is clear, no flying sand exists basically, the caking property of the clinker is good, no reducing material exists, the fluctuation of the vertical lifting weight of the clinker is 1237-1391 g/L, the fluctuation of the f-CaO is 0.5-1.2%, and the operation condition of the kiln system is normal. The kiln tail exhaust emission has no negative influence, and the environmental protection on-line flue gas monitoring shows SO₂The emission value is slightly reduced, and the consumption of the denitrified ammonia water is also slightly reduced.

The head coal consumption of the coal for calcination is equivalent, the tail coal consumption reduction amplitude fluctuates between 27% and 66%, the average standard coal consumption of 3 days per ton of clinker is reduced to 79.6kg/t, and the standard coal consumption of per ton of clinker is reduced by 37.3 kg/t.

The clinker yield in 3 days is 2854t/d on average, and the yield is slightly increased.

The 3-day clinker sample analysis actual value fluctuation is lime saturation coefficient KH = 0.918-0.971, silicic acid rate SM = 2.39-2.73, and aluminum oxygen rate IM 1.37-1.59; the phase fluctuation of the cooked material liquid is 22.8-26.3%, the strength fluctuation of the cooked material is 28.7-33.9 MPa in 3d compressive strength and 57.8-69.7 MPa in 28d compressive strength, the water requirement fluctuation of the standard consistency is 22.4-26.1%, the fluidity fluctuation is 180-186 mm, and the coagulation time fluctuation is 103-128 min in initial coagulation and 135-157 min in final coagulation. Namely, the quality stability of the clinker produced by adopting a three-rate value interval fluctuation control method is improved rather than the normal homogenization and stabilization three-rate value control method, and all physical and mechanical performance indexes of the clinker are improved.

The production test shows that the method for producing the silicate clinker by using the coal gangue to replace partial tailing coal and the silicon-aluminum raw material is feasible, and the mixed gangue accumulating the coal gangue dump can save a large amount of tailing coal at one time and save the tailing coal by 50.65 percent on average; and secondly, the clinker aggregate can replace a large amount of clay shale silicon-aluminum raw materials, can effectively solve the problem that the working condition of a kiln system is influenced by crusting and blocking caused by the characteristics of coal gangue, can improve the quality and the physical and mechanical properties of clinker, and has no negative influence on the emission of smoke.

Example 4

The embodiment is carried out on a certain phi 4.8 x 74m cement production line with a five-stage cyclone preheater precalcination kiln drying method, and the raw material ingredients for normal production are as follows: the fire coal is low-sulfur bituminous coal with 28-36% of volatile matter and 5800-6200 Kcal/kg of calorific value, and the clinker rate value is controlled to be lime saturation coefficient KH =0.90 +/-0.02, silicic acid rate SM =2.5 +/-0.1 and aluminum oxide rate IM ═ 1.5 +/-0.1. In the production, the ratio of head coal to tail coal of the coal for calcination is about 0.36 of head coal to 0.64 of tail coal, the kiln tail smoke chamber, the throat and the kiln are slightly skinned and long-looped, the kiln condition is stable, and a small amount of Zongzi reducing materials are mixed in the clinker. The average output of clinker under normal kiln conditions is 5835t/d, the actual standard coal consumption of the clinker is 107.6kg/t, the vertical lifting weight fluctuation of the clinker is 1210-1340 g/L, the f-CaO fluctuation is 0.3-1.0%, the phase fluctuation of the clinker is 23.6-25.4%, the strength fluctuation of the clinker is 26.0-34.0 MPa in 3d and 54.0-59.0 MPa in 28d, the water demand fluctuation of the standard consistency is 22.5-27.5%, the fluidity fluctuation is 175-185 mm, the coagulation time fluctuation is 97-137 min in initial coagulation and 125-165 min in final coagulation.

In the embodiment, coal gangue is taken from the accumulated coal gangue hill and is coal gangue mixed with white gangue and gangue separation, 81 coal gangue samples are taken according to a sampling routine for analysis, and the industrial analysis values of the coal gangue fluctuate within the range that ash (Aad) is 54.7-90.8%, volatile matter (Vad) is 3.7-21.6%, moisture (Mad) is 0.25-6.9%, fixed carbon (FCad) is 1.6-15.3%, and heat value (Qnet. ad) is 139-2287 × 4.18.18 kJ/kg., wherein the fluctuation range of main chemical components (w) is SiO₂45.8～68.7%、A1₂O₃5.3～22.4%、Fe₂0₃2.9～8.3%、CaO 1.2～7.8% 、MgO 0.7～3.9%、K₂O 0.6～2.3%、Na₂O 0.4～1.6%、SO₃0.2～4.1%、P₂O₅0.00~0.12%、TiO₂0.00-1.14% and Loss on ignition (Loss) 7.3-26.4%. The coal gangue modified combustion improver for the test is provided by the development Limited company of the little Yi's unconformable environmental energy science and technology in Hunan province (liquid No. Zc-R1), and the main component is a liquid mixture of an oxidant and silica gel.

Repeatedly analyzing and evaluating with a cement plant, and adopting a three-rate value interval fluctuation control method to draw up 10-15% of the alumino-silica raw material shale to be replaced by the gangue in the batch, wherein the clinker three-rate value is controlled and set to be an interval range rate value control of a lime saturation coefficient KH = 0.88-0.95, a silicic acid rate SM = 2.35-2.75 and an alumina rate IM 1.35-1.75.

In the embodiment, the coal gangue is used for replacing part of the tail coal and the alumino-silica raw material-shale, and the production of the silicate clinker is implemented by replacing part of the tail coal and the alumino-silica raw material with the coal gangue according to the following steps:

(1) preparing powder from two components: adding 0.3% modified sintering aid by mass into the coal gangue, mixing, grinding and modifying to prepare coal gangue powder with fineness of 80um and surplus sieve of 12%; mixing and grinding limestone serving as a calcareous raw material, a siliceous raw material, siliceous correcting material silica and ferrous correcting material pyrite slag into raw material powder with fineness of 80um and screen residue of 18 percent;

(2) preheating, mixing and decomposing: continuously feeding the gangue powder obtained in the step (1) and the raw material powder into a preheater system according to the mass ratio of = 10-16: 90-84; the gangue powder is metered and continuously fed into an upstream air pipe of a C5 cyclone preheater of a five-stage preheater system of a dry cement production line; raw meal powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, and is discharged into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw meal powder which is distilled from a cone part of the C3 cyclone preheater, the gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters the C4 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw meal powder; the preheated mixed raw meal powder is sent into a decomposing furnace through a conical distillation pipe of a C4 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw meal powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposing calcium carbonate in the mixed raw meal powder, and inorganic minerals of the coal gangue are thermally decomposed into active oxides which are all components of raw meal; adding and reducing the tail coal dosage in time according to the 870 +/-10 ℃ fluctuation range of the outlet temperature of the decomposing furnace so as to ensure the decomposition rate; mixed raw meal powder pre-decomposed in the decomposing furnace enters a C5 cyclone preheater along with pulling air, enters a smoke chamber through a fractionating pipe at the cone part of the C5 cyclone preheater and is sent into a rotary kiln;

(3) oxidative calcination: calcining the material fed into the rotary kiln in the step (2) into silicate clinker (clinker firing temperature 1450 ℃) by adopting strong-firing kiln head with one fire and adjusting oxidizing atmosphere in the rotary kiln controlled by wind; in order to stabilize the firing quality of silicate clinker (aiming at the problems that the fuel adopted by the plant is semi-bituminous coal and actually is blended coal mainly comprising anthracite, the flame of a kiln head with poor combustion performance is burnt out and cut off, and the bituminous coal with good combustion performance is inconvenient to replace due to large quantity of stored coal, a mature coal catalytic oxidation combustion method is adopted for the semi-bituminous coal fuel in the experimental stage to ensure that one fire at the kiln head is well fired), the outlet temperature of a decomposing furnace is controlled to be 870 +/-5 ℃, the tail coal consumption is dynamically and timely increased or decreased according to the fluctuation of the actual heat value of coal gangue powder, so as to prevent the excessive or insufficient fuel (the excessive fuel can not burn out carbon in time to cause reduction, skinning and sticking of C5, a blanking distillation tube, a kiln tail smoke chamber and a necking, and the insufficient fuel affects the furnace temperature and the kiln condition), the furnace temperature is increased (the heat value of coal gangue is high) to reduce the feeding amount of the tail coal, and the furnace temperature is decreased (the heat value of coal gangue is low) to increase the feeding amount of the tail coal.

The test is continuously operated for 73.4 hours, the preheater, a kiln tail smoke chamber, a throat and the kiln are not obviously skinned and stuck, the kiln head is clear and basically has no flying sand, the caking property of clinker is good, no reducing material is seen, the fluctuation of the vertical lifting weight of the clinker is 1280-1380 g/L, the fluctuation of f-CaO is 0.5-1.0%, and the operation condition of the kiln system is normal. The kiln tail exhaust emission does not have any negative effect, and the environmental protection on-line flue gas monitoring shows that the SO2 emission value is slightly reduced, and the denitration ammonia water consumption is also slightly reduced.

The head coal consumption of the coal for calcination is equivalent, the tail coal consumption reduction amplitude fluctuates between 33 and 72 percent, the average standard coal consumption of 3 days per ton of clinker is reduced to 76.8kg/t, and the standard coal consumption of per ton of clinker is reduced by 30.8 kg/t.

The clinker yield in 3 days is 5943t/d on average, and the yield is slightly increased.

The 3-day clinker sample analysis actual value fluctuation is lime saturation coefficient KH = 0.901-0.942, silicic acid rate SM = 2.33-2.68, and aluminum oxygen rate IM 1.39-1.70; the phase fluctuation of the cooked material liquid is 23.7-26.8%, the strength fluctuation of the cooked material is 27.8-34.6 MPa in 3d compressive strength and 57.4-62.7 MPa in 28d compressive strength, the water requirement fluctuation of the standard consistency is 22.7-26.5%, the fluidity fluctuation is 176-188 mm, the setting time fluctuation is 94-135 min in initial setting and 127-168 min in final setting. Namely, the quality stability of the clinker produced by adopting a three-rate value interval fluctuation control method is improved rather than the normal homogenization and stabilization three-rate value control method, and all physical and mechanical performance indexes of the clinker are improved.

The production test shows that the method for producing the silicate clinker by using the coal gangue to replace partial tailing coal and the silicon-aluminum raw material is feasible, and the mixed gangue accumulated in the coal gangue dump can save a large amount of tailing coal at one time, and the average saving of the tailing coal reaches 44.73%; and secondly, the clinker aggregate can replace a large amount of shale-like silicon-aluminum raw materials, effectively solve the problem that the working condition of a kiln system is influenced by crusting and blocking caused by the characteristics of coal gangue, improve the quality and the physical and mechanical properties of clinker aggregate, and has no negative influence on the emission of smoke.

Example 5

The embodiment is carried out on a certain phi 4.4 multiplied by 53m dry cement production line with a six-stage cyclone preheater pre-decomposition ultra-short kiln, and the raw material ingredients for normal production are as follows: the lime-based coal is prepared from limestone serving as a calcareous raw material, waste clay serving as a silicon-aluminum raw material, silica serving as a siliceous correction material and iron powder serving as an iron correction material, wherein the coal is low-sulfur bituminous coal with the volatile matter of 28-32% and the calorific value of 5600-6000 Kcal/kg, and the clinker rate value is controlled to be KH =0.90 +/-0.02, the silicic acid rate SM =2.4 +/-0.1 and the aluminum oxygen rate IM = 1.5 +/-0.1. In the production, the ratio of the head coal to the tail coal of the coal for calcination is about 0.4 of the head coal to 0.6 of the tail coal, the kiln tail smoke chamber, the throat and the kiln are moderately skinned and long-looped, the kiln condition is stable, and a small amount of Zongzi reducing materials are mixed in the clinker. The average output of clinker under normal kiln conditions is 3108t/d, the actual standard coal consumption of the clinker is 114.8kg/t, the vertical lifting weight fluctuation of the clinker is 1130-1300 g/L, the f-CaO fluctuation is 0.7-1.5%, the phase fluctuation of the clinker is 24.6-26.7%, the strength fluctuation of the clinker is 24.7-30.5 MPa in 3d compressive strength and 53.5-57.0 MPa in 28d compressive strength, the water demand fluctuation of standard consistency is 24.5-28.0%, the fluidity fluctuation is 165-180 mm, the coagulation time fluctuation is 103-142 min in initial coagulation and 136-193 min in final coagulation.

In the embodiment, the gangue is selected from gangue discarded in coal mining operation of coal mine, is sandstone gangue, is directly transported to a factory from a coal mine, 49 gangue samples are taken according to sampling rules for analysis, and the industrial analysis values of the gangue fluctuate within the range of 60.3-90.7% of ash (Aad), 3.6-16.8% of volatile matter (Vad), 2.7-6.3% of water (Mad), 2.1-12.3% of fixed carbon (FCad), 475-1975 × 4.18.18 kJ/kg. main chemical components (w) fluctuation range of SiO₂53.7～66.8%、A1₂O₃6.3～19.4%、Fe₂O₃2.6～5.3%、CaO 1.4～6.9% 、MgO 0.6～3.1%、K₂O 0.7～2.1%、Na₂O 0.4～1.1%、SO₃0.7～3.8%、P₂O₅0.00~0.15%、TiO₂0.00-0.59% and Loss on ignition (Loss) 9.0-28.3%. The coal gangue modified combustion improver for the test is provided by the development Limited company of the little Yi's unconformable environmental energy science and technology in Hunan province (liquid No. Zc-R1), and the main component of the coal gangue modified combustion improver is a liquid mixture of an oxidant, silica gel and aluminum gel.

Repeatedly analyzing and evaluating with a cement plant, and adopting a three-rate value interval fluctuation control method to draw up the gangue in the batch to replace 10-16% of waste clay of the silicoaluminophosphate raw material, wherein the clinker three-rate value is controlled by setting interval range rate values of lime saturation coefficient KH = 0.88-0.96, silicic acid rate SM = 2.30-2.70 and alumina rate IM 1.30-1.70.

In this example, it is proposed to replace part of the tail coal and the waste clay from the alumino-silica raw material with the coal gangue, and the silicate clinker is produced by replacing part of the tail coal and the alumino-silica raw material with the coal gangue according to the following steps:

(1) preparing powder from two components: adding 0.3% modified sintering aid by mass into the coal gangue, mixing, grinding and modifying to prepare coal gangue powder with fineness of 80um and screen residue of 16%; mixing and grinding the calcium raw material limestone, siliceous correction material sandstone and iron correction material pyrite cinder into raw material powder with fineness of 80um and residual sieve of 18 percent;

(2) preheating, mixing and decomposing: respectively and continuously feeding the gangue powder obtained in the step (1) and the raw material powder into a preheater system according to the mass ratio of = 10-17: 90-83; the gangue powder is metered and continuously fed into an upstream air pipe of a C6 cyclone preheater of a six-stage preheater system of a dry-process cement production line; raw material powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, is discharged into an upstream air pipe of a C5 cyclone preheater to be pulled into a C4 cyclone preheater along with air, and is discharged into an upstream air pipe of a C6 cyclone preheater from a C4 cyclone preheater to be pulled into a C5 cyclone preheater along with air; after being continuously mixed with raw meal powder which is distilled from a cone part of the C4 cyclone preheater, the gangue powder fed into an ascending air pipe of the C6 cyclone preheater enters the C5 cyclone preheater along with wind, and is mixed with the raw meal powder through the ascending air pipe of the C6 cyclone preheater and the C5 cyclone preheater to form mixed raw meal powder; the preheated mixed raw meal powder is sent into a decomposing furnace through a conical distillation pipe of a C5 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw meal powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposing calcium carbonate in the mixed raw meal powder, and inorganic minerals of the coal gangue are thermally decomposed into active oxides which are all components of raw meal; adding and reducing the tail coal dosage in time according to the 870 +/-10 ℃ fluctuation range of the outlet temperature of the decomposing furnace so as to ensure the decomposition rate; mixed raw meal powder pre-decomposed in the decomposing furnace enters a C6 cyclone preheater along with pulling air, enters a smoke chamber through a fractionating pipe at the cone part of the C6 cyclone preheater and is sent into a rotary kiln;

(3) oxidative calcination: calcining the material fed into the rotary kiln in the step (2) into silicate clinker (clinker firing temperature 1450 ℃) by adopting strong-firing kiln head with one fire, and adjusting the oxidizing atmosphere in the rotary kiln under the control of air; in order to stabilize the firing quality of silicate clinker (aiming at the problems that the fuel adopted by the plant is semi-bituminous coal, actually is blended coal mainly comprising anthracite, the burning performance of the kiln head is poor, the flame is burnt out and cut off, and the bituminous coal with good burning performance is inconvenient to replace due to large coal inventory, the semi-bituminous coal fuel adopts a mature coal catalytic oxidation burning method to ensure that the kiln head is burnt one fire); and according to the fluctuation range of the outlet temperature of the decomposing furnace of 870 +/-10 ℃, according to the condition of fluctuation of the actual heat value of the coal gangue powder, the tail coal consumption is dynamically and timely increased or decreased so as to prevent excessive fuel or insufficient fuel (carbon which is not combusted in time due to excessive fuel can cause reduction, skinning, sticking and blocking of C5, a discharging distillation tube, a kiln tail smoke chamber and a throat, and the furnace temperature and the kiln condition are influenced due to insufficient fuel), reduce the tail coal feeding amount when the furnace temperature rises (the heat value of the coal gangue is high), and increase the tail coal feeding amount when the furnace temperature falls (the heat value of the coal gangue is low).

The test is continuously operated for 74 hours, the preheater, the kiln tail smoke chamber, the necking and the kiln are not obviously skinned and stuck, the kiln head is clear, no flying sand exists basically, the caking property of the clinker is good, no reducing material exists, the fluctuation of the vertical lifting weight of the clinker is 1281-1382 g/L, the fluctuation of f-CaO is 0.5-1.0%, and the operation condition of the kiln system is normal. The kiln tail exhaust emission has no negative influence, and the environmental protection on-line flue gas monitoring shows SO₂The emission value is slightly reduced, and the consumption of the denitrified ammonia water is also slightly reduced.

The head coal consumption of the coal for calcination is equivalent, the tail coal consumption reduction amplitude fluctuates between 28 and 83 percent, the average standard coal consumption of 3 days per ton of clinker is reduced to 78.7kg/t, and the standard coal consumption of per ton of clinker is reduced by 36.1 kg/t.

The clinker yield is 3307t/d on average in 3 days, and the productivity is improved.

The analytical actual value fluctuation of the clinker sample in 3 days is lime saturation coefficient KH = 0.908-0.947, silicic acid rate SM = 2.39-2.63, and aluminum oxide rate IM 1.37-1.61; the phase fluctuation of the cooked material liquid is 24.1-26.3%, the strength fluctuation of the cooked material is 27.9-33.4 MPa in 3d compressive strength and 56.8-61.7 MPa in 28d compressive strength, the water requirement fluctuation of the standard consistency is 22.6-25.8%, the fluidity fluctuation is 180-188 mm, and the coagulation time fluctuation is 94-123 min in initial coagulation and 126-155 min in final coagulation. Namely, the quality stability of the clinker produced by adopting a three-rate value interval fluctuation control method is improved rather than the normal homogenization and stabilization three-rate value control method, and all physical and mechanical performance indexes of the clinker are improved.

The production test shows that the method for producing the silicate clinker by using the coal gangue to replace partial tailing coal and the silicon-aluminum raw material is feasible, and the mixed gangue accumulating the coal gangue dump can save a large amount of tailing coal at one time, and the average saving of the tailing coal reaches 52.41 percent; and secondly, a large amount of clay-like silicoaluminophosphate raw materials can be replaced, the problem that the working condition of a kiln system is influenced by crusting and blocking caused by the characteristics of coal gangue can be effectively solved, the quality and the physical and mechanical properties of clinker can be improved, and no negative influence is caused on smoke emission.

Claims

1. A method for producing silicate clinker by using coal gangue to replace tail coal and silicon-aluminum raw materials is characterized in that: the method comprises the following steps:

(2) preheating, mixing and decomposing: continuously feeding the coal gangue powder and the raw material powder obtained in the step (1) into a preheater of a dry-process cement clinker production line respectively according to the mass ratio of 3-20: 97-80 for preheating and mixing, feeding into a decomposing furnace for decomposition, and feeding into a rotary kiln of the dry-process cement clinker production line;

2. The method for producing the silicate clinker by using the coal gangue to replace the tail coal and the silicon-aluminum raw material according to claim 1, wherein the method comprises the following steps: in the step (1), the coal gangue is raw coal gangue and comprises various white gangue with low calorific value of 100 multiplied by 4.18KJ/Kg to 2800 multiplied by 4.18KJ/Kg, clay rock coal gangue for selecting gangue, sandstone coal gangue (siliceous rock coal gangue), carbonate coal gangue and aluminous rock coal gangue.

3. The method for producing the silicate clinker by using the coal gangue to replace the tail coal and the silicon-aluminum raw material according to the claim 1 or 2, which is characterized in that: in the step (1), the mass of the modified sintering aid added into the coal gangue is less than or equal to 3 percent of the mass of the coal gangue; preferably 0.3 to 2.0%.

4. The method for producing the silicate clinker by using the coal gangue instead of the tail coal and the alumino-silica raw material according to one of the claims 1 to 3, wherein the method comprises the following steps: in the step (1), the modified sintering aid is a mixture of an oxidant and one or two of silica gel and alumina gel.

5. The method for producing the silicate clinker by using the coal gangue instead of the tail coal and the alumino-silica raw material according to one of the claims 1 to 4, wherein the method comprises the following steps: in the step (1), the fineness of the coal gangue powder is 80um, and the screen residue is less than or equal to 18 percent; the fineness of the raw meal powder is 80um with the screen residue less than or equal to 27 percent.

6. The method for producing the silicate clinker by using the coal gangue instead of the tail coal and the alumino-silica raw material according to one of the claims 1 to 5, wherein the method comprises the following steps: in the step (1), according to the actual conditions of coal gangue, siliceous correcting material, aluminum correcting material, iron correcting material, silicon-aluminum raw material and calcareous raw material, selecting proper interval rate values to control in the ranges of lime saturation coefficient KH = 0.86-0.98, silicic acid rate SM = 2.2-3.2 and aluminum oxide rate IM 1.3-1.9; when the main chemical component of coal gangue is SiO₂、A1₂O₃、Fe₂O₃CaO, MgO phasesWhen the cement clinker is stable or easy to homogenize and stabilize, a three-rate value interval fluctuation control method calculated according to chemical components can be converted into a normal stable raw clinker three-rate value control mode in dry cement production while a process of respectively feeding bi-component powder into a preheater is adopted.

7. The method for producing silicate clinker by using coal gangue instead of tailings and alumino-silicate raw materials according to any one of claims 1 to 6, wherein the method comprises the following steps: in the step (2), when the preheater system of the dry-process cement clinker production line is a five-stage cyclone preheater, the gangue powder obtained in the step (1) is metered and continuously fed into an upstream air pipe of a C5 cyclone preheater of the five-stage preheater system of the dry-process cement production line; continuously metering the raw meal powder obtained in the step (1), feeding the raw meal powder from an upstream air pipe of a C2 cyclone preheater, drawing the raw meal powder into a C1 cyclone preheater along with air, then unloading the raw meal powder into an upstream air pipe of a C3 cyclone preheater to draw a C2 cyclone preheater, then unloading the raw meal powder into an upstream air pipe of a C4 cyclone preheater from a C2 cyclone preheater to draw a C3 cyclone preheater along with air, and then unloading the raw meal powder into an upstream air pipe of a C5 cyclone preheater; after being continuously mixed with raw material powder which is distilled from a cone part of a C3 cyclone preheater, the coal gangue powder fed into an ascending air pipe of the C5 cyclone preheater enters a C4 cyclone preheater along with wind, and is mixed with the raw material powder through the ascending air pipe of the C5 cyclone preheater and the C4 cyclone preheater to form mixed raw material powder; the preheated mixed raw material powder is sent into a decomposing furnace through a cone-shaped distillation pipe of a C4 cyclone preheater, the pre-decomposed mixed raw material powder in the decomposing furnace enters a C5 cyclone preheater along with the drawing air, and enters a smoke chamber through a cone-shaped distillation pipe of a C5 cyclone preheater and is sent into a rotary kiln.

8. The method for producing silicate clinker by using coal gangue instead of tailings and alumino-silicate raw materials according to any one of claims 1 to 6, wherein the method comprises the following steps: in the step (2), when the dry-process cement clinker production line is a six-stage cyclone preheater, the gangue powder obtained in the step (1) is metered and continuously fed into an upstream air pipe of a C6 cyclone preheater of the six-stage preheater system of the dry-process cement production line; raw material powder is fed from an upstream air pipe of a C2 cyclone preheater through continuous metering, is pulled into a C1 cyclone preheater along with air, is discharged into an upstream air pipe of a C3 cyclone preheater to be pulled into a C2 cyclone preheater, is discharged into an upstream air pipe of a C4 cyclone preheater from the C2 cyclone preheater to be pulled into a C3 cyclone preheater along with air, is discharged into an upstream air pipe of a C5 cyclone preheater to be pulled into a C4 cyclone preheater along with air, and is discharged into an upstream air pipe of a C6 cyclone preheater from a C4 cyclone preheater to be pulled into a C5 cyclone preheater along with air; after being continuously mixed with raw material powder which is distilled from a cone part of a C4 cyclone preheater, the coal gangue powder fed into an ascending air pipe of the C6 cyclone preheater enters a C5 cyclone preheater along with wind, and is mixed with the raw material powder through the ascending air pipe of the C6 cyclone preheater and the C5 cyclone preheater to form mixed raw material powder; the preheated mixed raw material powder is fed into a decomposing furnace through a cone-shaped distillation tube of a C5 cyclone preheater, carbon combustible substances contained in coal gangue in the preheated mixed raw material powder are burnt out in smokeless suspension combustion in the decomposing furnace, heat energy is supplied for decomposition of calcium carbonate in the mixed raw material powder, inorganic minerals of the coal gangue are thermally decomposed into components of which active oxides are all raw material components, the pre-decomposed mixed raw material powder in the decomposing furnace enters a C6 cyclone preheater along with pulling air, and the mixed raw material powder enters a smoke chamber through the cone-shaped distillation tube of the C6 cyclone preheater and is fed into a rotary kiln.

9. The method for producing silicate clinker by using coal gangue instead of tailings and alumino-silicate raw materials according to any one of claims 1 to 8, wherein the method comprises the following steps: in the step (2), the tail coal consumption is increased or decreased in due time according to the instant fluctuation range of the outlet temperature of the decomposing furnace of 860-890 ℃, preferably 875 +/-10 ℃, so that the heat value of the coal gangue is high or the consumption proportion is increased, the tail coal consumption is reduced when the outlet temperature of the decomposing furnace is increased, the heat value of the coal gangue is low or the consumption proportion is reduced, and the tail coal consumption is increased when the outlet temperature of the decomposing furnace is reduced.

10. The method for producing silicate clinker by using coal gangue instead of tailings and alumino-silicate raw materials according to any one of claims 1 to 9, wherein the method comprises the following steps: in the step (3), the temperature of the oxidizing atmosphere calcination is 1400-1500 ℃, preferably 1450 ℃.