Disclosure of Invention
The invention aims to provide a three-component portland cement calcined clinker and a preparation method thereof, which aim to solve the problem that the cement manufacturing cost is greatly increased due to the phenomenon that siliceous correction raw material sandstone is difficult to feed and expensive in cement production.
In order to solve the technical problems, the invention adopts the following technical scheme:
the three-component portland cement calcined clinker is characterized by comprising the following components in percentage by mass: 82.6 to 86.6 percent of limestone, 10 to 15 percent of clay and 1.4 to 4.4 percent of iron powder.
The further technical scheme is as follows: the alkali content of the clay is 1-5%.
The further technical scheme is as follows: 84.6% of limestone, 13% of clay and 2.4% of iron powder, wherein the alkali content of the clay is 2.4%.
The further technical scheme is as follows: 84.6% of limestone, 13% of clay and 2.4% of iron powder are raw materials and are fired into product clinker, and the value range of the three-rate value of the product clinker is as follows: KH ═ 0.92 ± 0.01, SM ═ 2.3 ± 0.1, and IM ═ 1.6 ± 0.1.
A preparation process of a three-component portland cement calcined clinker comprises the following steps:
s1, determining a three-rate value range of clinker, and determining the three-rate value range of clinker burdened with three components according to the three-rate value range of clinker, substituted components of raw combustion materials and kiln type specified by the industry standard;
s2, raw material proportioning, determining the proportion of limestone, clay and iron powder according to the clinker ternary value range in S1, and crushing and drying the three materials;
s3, grinding the raw material, namely, feeding all the components of the raw material and the raw combustion material in the S2 into a grinding machine, sieving the raw material by a sieve of 180-200 meshes, wherein the balance of the sieve is 5-8%, and feeding the raw material into a raw material homogenizing storage warehouse;
s4, preheating raw materials, drying the raw material powder and the raw combustion material powder in the S3 by a preheater by utilizing hot air in the kiln, and putting the raw material powder and the raw combustion material powder into a dry material homogenizing storage warehouse;
s5, calcining the raw material, namely mixing and homogenizing the raw material powder and the raw combustion material powder in the S4 according to a certain mass percentage, and putting the mixture into a kiln for calcination;
wherein the calcining mode is thin material fast burning, the short flame fast burning of a kiln head coal injection pipe is adjusted, the length of a burning zone is shorter than 25m, the temperature of the burning zone is 1450-;
s6, quenching the clinker, wherein the air cooling time of the clinker in the S4 is less than 20min after the clinker passes through the grate cooler, the machine outlet temperature is not higher than 100 ℃, the thickness of a material layer is 400-600mm, and the rapid quenching of thin material full penetration is carried out on the clinker;
and S7, inspecting the quality of the clinker, selecting the clinker, sampling, preparing a sample, dividing, inspecting, and warehousing the qualified clinker in batches.
The further technical scheme is as follows: the clay in the S2 raw material is surface soil stripped by limestone ore.
The further technical scheme is as follows: after drying in the S2, the water content of the limestone is 0.5% -1%, the water content of the clay is less than 1.5%, and the water content of the iron powder is less than 1.5%.
The further technical scheme is as follows: in the S4, the preheating of raw meal is divided into a drying stage and a dehydration stage, wherein the drying stage controls the preheater to be between 100 and 150 ℃, and the dehydration stage controls the preheater to be between 400 and 600 ℃.
The further technical scheme is as follows: the raw combustion material is coal ash with the sulfur content of less than 1.5 percent.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention provides a three-component portland cement calcined clinker, which is prepared by crushing, proportioning and grinding limestone, clay and iron powder which are used as main raw materials to prepare raw materials, calcining the raw materials in a cement kiln, canceling siliceous correction raw material sandstone components, readjusting the three-rate value of the clinker according to the conditions of raw material grade, raw material preparation, clinker calcining process, cement variety production and the like under the industrial standard, and recalculating the raw material proportion of the limestone, the clay and the iron powder according to the three-rate value of the clinker, thereby reducing the consumption of the sandstone, further reducing mining and protecting the natural environment, on the other hand, compared with the prior four-group distribution method production, the raw material ton cost is reduced by 1 ten thousand per ton, the clinker cost is reduced by 1.54 ten thousand per ton, the production cost is greatly reduced, and the production benefit is improved.
2. When the clinker is produced by adjusting the three distribution methods, the raw material alkali content is increased because the clay usage amount is sharply increased, and the silicate ratio of the calcined clinker is reduced.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1:
example 1 shows an example, a three-component portland cement clinker calcined clinker characterized by comprising, in mass%: 82.6 to 86.6 percent of limestone, 10 to 15 percent of clay and 1.4 to 4.4 percent of iron powder.
Preferably, the alkali content of the clay is 1-5%.
Preferably, limestone 84.6%, clay 13% and iron powder 2.4%, wherein the alkali content of the clay is 2.4%.
Preferably, the limestone 84.6%, the clay 13% and the iron powder 2.4% are raw materials and are fired into product clinker, and the value range of the three-rate value of the product clinker is as follows: KH ═ 0.92 ± 0.01, SM ═ 2.3 ± 0.1, and IM ═ 1.6 ± 0.1.
The existing portland cement clinker is produced by mixing four or more materials, wherein the main materials comprise a calcareous raw material, a argillaceous raw material, an iron correcting raw material, an aluminum correcting raw material and a siliceous correcting raw material. The four-component batching is a special raw material batching scheme for producing the silicate calcined clinker in China and is also the most basic raw material requirement for producing cement in China. The material is limestone, clay (clay) or fly ash, iron powder or iron ore, sandstone or shale, etc. which are mixed and ground according to a certain proportion, and are made into clinker with certain mineral composition after high-temperature calcination, and the third-rate value of the calcined clinker is 0.910 +/-0.02 according to the industry standard; SM 2.70 ± 0.10; IM is 1.70 ± 0.10.
Considering that in recent years, siliceous correction raw material sandstone is difficult to feed and expensive, cement manufacturing cost is greatly increased, and responds to national integrated mine resources, mining is reduced, and calls for resources and environment are protected, four groups of distribution materials are changed into three-component ingredients, limestone, clay and iron powder are used as main raw materials, raw materials are prepared through crushing, blending and grinding, then the raw materials are calcined in a cement kiln, siliceous correction raw material sandstone components are cancelled, under the condition of ensuring that each index of cement is qualified and the using quality meets the standard, the three-rate value KH of clinker is readjusted to be 0.92 +/-0.01, SM to be 2.3 +/-0.1, and IM to be 1.6 +/-0.1 according to the conditions of raw combustion material grade (substituted components of coal), raw material preparation and clinker calcination process, cement variety and the like under the industrial standard. And then the raw material proportion of limestone, clay and iron powder is recalculated according to the three-rate value of the clinker, wherein the limestone accounts for 82.6-86.6 percent, the clay accounts for 10-15 percent and the iron powder accounts for 1.4-4.4 percent. On one hand, the usage amount of sandstone is reduced, so that mining is reduced, the natural environment is protected, on the other hand, compared with the prior production of four groups of distribution methods, the cost of raw materials per ton is reduced by 1 ten thousand per ton, the cost of clinker is reduced by 1.54 ten thousand per ton, the production cost is greatly reduced, and the production benefit is improved.
TABLE 1.1
According to the experimental data in table 1.1, four sets of experiments were performed within the range of the mixture ratio of limestone, clay and iron powder, showing that: the free calcium oxide f-CaO in the calcined clinker is increased along with the increase of the content of limestone, the alkali content in the clinker is increased along with the increase of clay, the intermediate value of the mass percentage of the raw meal formula with three components of limestone and clay can be selected by considering, but the excellence of the cement strength and the water demand in 3 days and 28 days is shown in an experimental group 2, and the optimized three groups of distribution ratios are determined: 84.6% of limestone, 13% of clay and 2.4% of iron powder.
TABLE 1.2
TABLE 1.3
Tables 1.2 and 1.3 show that the raw material production per ton of calcined clinker unit, the raw material per ton unit price and the monthly production cost in the enterprise are calculated by putting three-component formulas and four groups of distribution formulas into actual production respectively, the raw material per ton cost is reduced by 1 ten thousand per ton, the clinker cost is reduced by 1.54 ten thousand per ton, the production cost is greatly reduced, the production benefit is improved, and the cost of more than 300 ten thousand yuan can be saved according to the annual yield of the enterprise in the tables.
A preparation process of a three-component portland cement calcined clinker comprises the following steps:
s1, determining a three-rate value range of clinker, and determining the three-rate value range of clinker burdened with three components according to the three-rate value range of clinker, substituted components of raw combustion materials and kiln type specified by the industry standard;
s2, raw material proportioning, determining the proportion of limestone, clay and iron powder according to the clinker ternary value range in S1, and crushing and drying the three materials;
s3, grinding the raw material, namely, feeding all the components of the raw material and the raw combustion material in the S2 into a grinding machine, sieving the raw material by a sieve of 180-200 meshes, wherein the balance of the sieve is 5-8%, and feeding the raw material into a raw material homogenizing storage warehouse;
s4, preheating raw materials, drying the raw material powder and the raw combustion material powder in the S3 by a preheater by utilizing hot air in the kiln, and putting the raw material powder and the raw combustion material powder into a dry material homogenizing storage warehouse;
s5, calcining the raw material, namely mixing and homogenizing the raw material powder and the raw combustion material powder in the S4 according to a certain mass percentage, and putting the mixture into a kiln for calcination;
wherein the calcining mode is thin material fast burning, the short flame fast burning of a kiln head coal injection pipe is adjusted, the length of a burning zone is shorter than 25m, the temperature of the burning zone is 1450-;
s6, quenching the clinker, wherein the air cooling time of the clinker in the S4 is less than 20min after the clinker passes through the grate cooler, the machine outlet temperature is not higher than 100 ℃, the thickness of a material layer is 400-600mm, and the rapid quenching of thin material full penetration is carried out on the clinker;
and S7, inspecting the quality of the clinker, selecting the clinker, sampling, preparing a sample, dividing, inspecting, and warehousing the qualified clinker in batches.
Preferably, the clay in the raw material of S2 is surface soil stripped from limestone ore.
Preferably, after drying in S2, the water content of limestone is 0.5% to 1%, the water content of clay is less than 1.5%, and the water content of iron powder is less than 1.5%.
Preferably, in S4, the preheating of raw meal is divided into a drying stage and a dehydrating stage, the drying stage controls the preheater at 100-150 ℃, and the dehydrating stage controls the preheater at 400-600 ℃.
Preferably, the raw combustion material is coal ash with the sulfur content of less than 1.5%.
TABLE 2.1
TABLE 2.2
The data in tables 2.1 and 2.2 are from a comparison of the preferred three component formulation with the existing preferred four component formulation, with the three component formulation having slightly higher 3 day strength and slightly lower 28 day strength than the four component clinker. The clinker free calcium qualification rate is low, mainly because of the use of more clay and the slightly higher alkali content in the clay, the kiln tail alkali enrichment during clinker calcination is likely to cause skinning, and the later strength of the clinker is affected when the clinker is cooled.
As the experimental data show that the clinker has slightly high alkali content and has certain influence on the quality of the clinker, the clay is completely taken from surface soil stripped from limestone mine, the alkali content is controlled to be about 2.4 percent, the clinker three-rate value is properly adjusted, the clinker lime saturation coefficient KH is adjusted to be 0.92 +/-0.01, the aluminum oxygen rate IM is adjusted to be 1.6 +/-0.1, the iron content in the clinker is increased, the liquid phase viscosity of the clinker is reduced, the easy burning property of the clinker is improved, the qualified rate of free calcium of the clinker is improved to be more than 93 percent after adjustment, and the later strength of the clinker is also improved.
The traditional preparation method of the portland cement calcined clinker is adjusted, so that the problems are solved:
the first step, according to the substituted components of the raw materials and the raw burning materials of three components to be used and the range of three rate values of the calcined portland cement clinker specified by reference industry standards, under the condition of ensuring that each index of the cement is qualified and the use quality meets the standard, the range of three rate values suitable for producing the calcined clinker by three components is determined again, and the value range of the three rate values of the product clinker is as follows: KH ═ 0.92 ± 0.01, SM ═ 2.3 ± 0.1, and IM ═ 1.6 ± 0.1. And secondly, determining the raw material proportion of limestone, clay and iron powder in the three components according to the three-rate value range of the clinker, crushing and drying the three raw materials, wherein after drying, the water content of the limestone is 0.5-1%, the water content of the clay is less than 1.5%, the water content of the iron powder is less than 1.5%, and the purpose of drying the raw materials is as follows: 1. the normal operation of the grinder in the subsequent steps is ensured, and abnormal phenomena such as ball wrapping, paste grinding, full grinding and the like are prevented; 2. is beneficial to the transportation, storage and homogenization of the powder in the subsequent steps. And thirdly, in the grinding of the raw materials, the fineness of the powder is required to pass through a 180-200-mesh sieve, the screen allowance is 5-8%, the fineness of the raw combustion material (coal) and the screen allowance are required to be 3-5%, the granularity of the pulverized coal is reduced, the combustion speed is improved, and in order to prevent the crusting in the kiln, the coal ash with the sulfur content of less than 1.5% is selected as the raw combustion material. And fourthly, preheating the raw material, wherein the preheating of the raw material is divided into a drying stage and a dehydration stage, the drying stage controls the preheater to be between 100 and 150 ℃, the dehydration stage controls the preheater to be between 400 and 600 ℃, the specific drying and dehydration time is adjusted according to an initial value measured by the water content of the raw material, the free water in the raw material is basically removed at the temperature of between 100 and 150 ℃, the clay and the like are heated to decompose into the hydration water, the coordination water of the raw material is basically removed at the temperature of between 400 and 600 ℃, and the temperature of the raw material is rapidly increased.
The key point is that the calcination and cooling are controlled, so that the three-component cement can reach the national standard of cement, specifically, the fifth step is raw material calcination, wherein the heated raw material and the raw combustion material powder are mixed and homogenized according to a certain mass percentage and are put into a kiln for calcination; the method is characterized in that the calcination mode is thin material fast burning, the reduction of the silicate ratio of the clinker means that the liquid phase amount is increased in the clinker calcination process, the clinker sintering range is narrowed, the calcination difficulty of a large kiln is increased, the crust of a preheater is increased, the kiln crust is easy to form a ring at the kiln tail and thicken, the damage risk of refractory bricks in the kiln is increased, and in order to solve the difficulties under the condition of ensuring the quality, the method has the advantages of wide thought and multiple attempts, finally is adjusted to be thin material fast burning in the kiln, and the short flame fast burning of a kiln head coal injection pipe is adjusted. The rotating speed of the kiln is accelerated, the filling rate in the kiln is reduced, and the filling rate in the kiln is reduced from original 8% to about 6% (optimally 6%). Meanwhile, short-flame and quick burning is carried out, the length of a burning zone is shortened, the temperature of the burning zone is increased, and the retention time of clinker in the burning zone is shortened. The length of the burning zone is shortened from the original 27m to about 23m (optimally 23 m). The temperature of the burning zone is increased from original 1400 ℃ to 1450 ℃ to 1500 ℃. Therefore, the retention time of the clinker in the burning zone is less than 10min, and the regulated burning is more stable; and sixthly, rapidly cooling the clinker, wherein the clinker in the S4 is rapidly cooled through full penetration of thin materials after passing through a grate cooler, rapidly burning the clinker, shortening a burning zone, and rapidly cooling the clinker when the clinker is taken out of the kiln, wherein the temperature of the clinker is relatively high and needs rapid cooling, otherwise, the clinker minerals are easy to deform and pulverize, and the quality of the clinker is reduced. In the production, the air quantity of the grate cooler is increased through adjustment, the grate cooler is subjected to material layer thinning operation, a thin material layer is kept as much as possible under the condition that short circuit is formed by ensuring that clinker is not blown through, the thickness of the final material layer is adjusted from 800mm to 500mm, under the condition, the temperature of the discharged clinker is reduced from 1200 ℃ to 100 ℃ within 20 mm after the discharged clinker passes through the grate cooler, and the rapid cooling of the full penetration of the discharged clinker in the shortest time is realized. And seventhly, selecting clinker, normally sampling, preparing a sample, dividing, inspecting, and warehousing in qualified batches, wherein the appearance of the produced qualified clinker is gray green, the particles are uniform, round and smooth, and the clinker is compact after being broken, the crystals are shiny and have no serious melting trace. The detection and analysis show that the properties of the clinker meet the national standard.
Reference throughout this specification to "one embodiment," "another embodiment," "an embodiment," "a preferred embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally in this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the scope of the invention to effect such feature, structure, or characteristic in connection with other embodiments.
Although the invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More specifically, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure and claims of this application. In addition to variations and modifications in the component parts and/or arrangements, other uses will also be apparent to those skilled in the art.