SU1583379A1 - Method of producing cement clinker - Google Patents

Abstract

The invention relates to the technology of production in living materials, mainly to methods for the production of cement clinker. The aim of the invention is to reduce dust removal from the furnace. In the claimed method of cement clinker production, coarse-grained marl with a grain size of 10-30 mm at a temperature of 300-600 ° C in an amount of 30-60% of the total raw sludge is introduced as an additive. The reduction in dust loss is 31.0-65.6%. 6 tab.

Description

The invention relates to the technology of production in living materials, mainly to methods for the production of cement clinker.

The aim of the invention is to reduce dust from the furnace.

The essence of the method is that with the introduction of crushed marl grain size of 10-30 mm in the preparatory zone of the furnace, not with its cold end, but directly into the heating zone in the part where the slurry temperature is 300-600 ° C, it provides a sharp thermal heating of marl, leading to a simultaneous loss of physical and hydrated water, disintegration of the clay molecule on SiO and ALjOj and loosening of the structure of marl grains as a result of abrupt removal of water vapor from the entire thickness of the marl grain, which leads to an increase in reactivity of Ksidov marl. Besides

In addition, the introduction of 30–60% crushed marl directly into the heating zone with a temperature of 300–600 ° C reduces the dust emissions from the furnace as a result of a 30–30 / o decrease in the amount of fine sludge and an additional 6.5–11% as a result of mixing and adhesion of fine heated sludge on marl with natural moisture.

For the implementation of the method, marls of a cement plant with a titer of 81.5 and 74.8% and humidity of 2 and 14%, and raw sludge with a saturation factor of 0.9, are used.

Slurry enters the rotary kiln from the cold end at 15-25 ° C and gradually heats up when moving up to the furnace towards the hot gases. Marl is fed directly to the heating zone at the site with a temperature of 300-600 ° C.

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The method is carried out as follows.

A portion of the samples of marl (by a known method) is introduced into the laboratory silicon furnace at 20 ° C and heated together with the furnace. Then, in the furnace preheated to 200, 300, 500, and 600 and 700 ° C, the second part of the samples of marl is introduced (according to the proposed method). When the temperature reaches 1350 and 1400 ° C, the samples are taken, annealed according to the known and proposed methods The intensity of the process of klinner formation is determined by non-predetermined CaO. The safety of the samples is determined at a maximum calcining temperature of 1450 ° C.

The effect of heat treatment

marl content Cao ". shown

in tab. 1 o

As can be seen from Table 1, the greatest intensification of the process of clinker formation occurs in the temperature range of 300-600 ° C, the CaO8 content in marl is the lowest. A decrease in the temperature of the preheating zone (less than 300 ° C) and an increase in (more than 600 ° C) lead to an increase in the CaO content and, accordingly, a decrease in the rate of clinker production.

At 1450 ° C in the calcined marl on the proposed method, the clinic formation processes are in the completion stage, whereas in the marl, annealed by a known method, at 1400 ° C, CaOC is 8.5%. The shape of the samples is retained, even when abruptly heated to 1450 ° C by the proposed method.

The intensification of the clinker formation process by the proposed method is shown in Table. 2,

As can be seen from the table. 2, with the introduction of marl by the proposed method into the heating zone at the site with a temperature of 300-600 ° C, the acceleration of CaO at 1350 ° C is 16.8-45.7%. The introduction of marl at 200 and 700 ° C is irrational, since the intensity of CaOv absorption is significantly reduced.

Thus, as a result of the sharp heat treatment of marl by the proposed method, when there is a simultaneous loss of physical and hydrated water, disintegration of the clay molecule on SiO and loosening of the structure of marl grains while cutting removing water from the entire thickness of the grain

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per marl, the reactivity of marl oxides is increased. The marl grains, both K-I and SOC, are not destroyed as a result of abrupt heat treatment according to the proposed method, but remain in shape until the end of the experiment (1450 ° C). Thus, the production of cement clinker by the proposed method does not lead to the scattering of marl grains and does not lead to an increase in dust removal from the furnace.

It is known that the foci of dust in the furnace are mainly in the preheating zone. The raw sludge in the preheating zone at 300-600 ° C is a dried fine material, the granules are usually not more than 20%. Therefore, the introduction of 30-60% marl with natural moisture with a grain size of 10-30 mm in the preparatory zone of the furnace, not from its cold end, but directly into the preheating zone, where the material temperature is 300- 600 ° C, results in a decrease in dust removal from the furnace as a result reducing by 30-60% the proportion of dried fine sludge capable of dust removal. So, if from rotary kilns 5 x x 185 m dust removal is on average equal to

; 300 t / h, while reducing by 30-60% the proportion of fine sludge dust removal is reduced by 9-18 t / h or 30-60%.

The research results are given in table. 3

Thus, the optimal amount of marl injected is 30-60%. Introducing less than 30% of marl is irrational due to the minimal positive effect on the reduction of dust removal. It is also unreasonable to introduce more than 60% marl, since this significantly reduces the dust removal capacity of the chain curtain due to the lack of wet sludge to cover 6–8 mm with the surface of the chain curtain and the internal surface of the furnace, which leads to a sharp increase in dust removal from the furnace.

At the same time, the introduction of marl directly into the heating zone at 300-600 ° C allows reducing dust removal and, as a result of mixing and sticking fine slime heated to 300-600 ° C on the surface of marl grain with natural humidity

The research results are given in table. four.

It has been established that an increase in the preheating temperature contributes to an increase in the adhesion of fine sludge onto marl. Thus, at a heating temperature of 300–600 ° C, an average of 14.3% (from 13.2 to 15.5%) of finely dispersed sludge adheres to marl with natural moisture.

The total reduction in dust removal from the furnace consists of reducing the amount of fine sludge due to the introduction of 30-60% marl (Table 3) and sticking 14.3% fine sludge

one

on grain marl.

The results are given in table. five,

Thus, the introduction of 30-60% marl into the heating zone at the site with a temperature of 300-600 ° C significantly reduces dust removal from the furnace.

It is not rational to introduce crushed marl with a size of less than 10 mm, since pulverized marl increases dust from the furnace. It is also not efficient to introduce crushed marl more than 30 mm, since at high temperatures it is difficult to form clinker granules.

Introduction directly to the heating zone at the site with a temperature of 3001

600 С 30-60% marl with a grain size of 10-30 mm with natural moisture reduces the average humidity up to 10% of the raw material entering the furnace by reducing the amount of wet sludge, while reducing fuel consumption for moisture evaporation from 510 to 335 kcal / kg wedge -. kerah.

The introduction of marl also contributes to the increase in the hydration activity of clinker calcined in laboratory Q

15 of the cold end, and directly into the heating zone on the site with a temperature of 300 to 600 ° C, will accelerate the absorption of calcium oxide 2.5-8.5%, to intensify the percent

20 to reduce clinker formation by 16.8-85.9 by 31-65.6%, dust removal due to reduction by 30-60% of fine persistent sludge and due to displacement of sticking heated to 300-600 ° C

25 ma for grain marl; stabilize the furnace operation mode and increase its utilization rate due to the amount of dust returned to the furnace; increase hydration ak

30% clinker by 3.5-11.5%; reduce the average moisture content of the raw material by 0.2-1 and heat loss by evaporation of water 4-165 kcal / kg.

35

oven at 1450 ° C with a holding time of 40 min (Table 6).

So, if, by a known method, the additional introduction of 20% of electrothermophosphorus slag, which reduces KN 300-600 ° C in an amount of 30-60% from mA from 1.10 to 0.91, makes it possible to obtain all raw sludge.

Claims (1)

Formula invented A method for the production of cement clinker, which involves preparing raw sludge, burning it in a rotary kiln, introducing an additive into the kiln's cooking zones, in which, with the aim of removing dust from the kiln, a coarse-grained grain with a grain size of 10 is added as an additive. -30 mm pr clinker with hydration activity of 58.1 MPa, then with the introduction of marl in the amount of 20, 40, 60%, it significantly accelerates the absorption of calcium oxide, for example, at 1400 ° C from 9.2 to 1.2%, and also increases the hydration clinker activity up to 58 - 66.7 MPa. Thus, the application of the proposed method for the production of cement clinker by introducing 30-60% marl with a grain size of 10-30 mm into the preparatory zones of the furnace not with its cold end, and directly into the heating zone at the site with a temperature of 300 to 600 ° C, accelerates the absorption of calcium oxide by 2.5-8.5%, to intensify the process clinker formation by 16.8-85.9%; reduce by 31-65.6%, dust removal from the furnace by reducing by 30-60% fine sludge and by displacing and sticking the sludge heated to 300-600 ° C for marl grain; stabilize the operation of the furnace and increase its utilization rate by reducing the amount of dust returned to the furnace; increase the hydration activity of clinker by 3.5-11.5%; reduce the average moisture content of the raw material by 0.2-10% and heat loss by evaporation of water by 4-165 kcal / kg. 300-600 ° C in the amount of 30-60% of the total raw sludge. Invention Formula A method for producing cement clinker, which includes preparing raw sludge, burning it in a rotary kiln, introducing an additive into the kiln preparatory zones, characterized in that, in order to reduce dust removal from the kiln, coarse-grained marl with a grain size of 10-30 mm is added as an additive Table 1 Marl with a caption of 81.5%  The amount of sludge is not enough to cover 6–8 mm with the surface of the chain curtain and the inner furnace, and dust removal begins to increase. 100% sludge 90% sludge + 10% marl 80% sludge + 20% marl 60% sludge + 40% marl 40% sludge + 60% marl 1583379Yu Continuation of table 3 Table 4 Table 5 Oh oh 3 + 1.615.3 6 + 3,331 12 + 6,662 18 + 9,993 P Editor N. Gulko Compiled by A. Kulabukhova Tehred A. Kravchuk Proofreader N. King Order 2228 Circulation 568 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 1583379 12 Table 6 Subscription