阅读说明：本技术 一种氧化铝熟料干法煅烧系统及其工作原理 (Alumina clinker dry calcining system and working principle thereof ) 是由 康宇 李安平 武艳文 于 2020-09-08 设计创作，主要内容包括：本发明涉及一种氧化铝熟料干法煅烧系统及其工作原理,包括预热器、回转窑和篦式冷却机；还包括压滤机、烘干粉碎装置、第一选粉系统、粉磨装置和第二选粉系统；压滤机的出料口与烘干粉碎装置的进料口相连,烘干粉碎装置的出料口与第一选粉系统的进料口相连,第一选粉系统的出料口与预热器的进料口相连,粉磨装置的出料口与第二选粉系统的进料口相连,第二选粉系统的出料口与第一选粉系统的进料口相连；本发明借助压滤机和烘干粉碎装置将赤泥中的水分除去并制成赤泥干粉,同时借助粉磨装置将赤泥干粉、石灰石和铝矾土的配料干粉以及碱均匀混合,然后再经预热器后喂入到回转窑中煅烧,进而大幅降低煅烧过程中所需的热耗,从而大幅降低了生产成本。(The invention relates to an alumina clinker dry calcining system and a working principle thereof, comprising a preheater, a rotary kiln and a grate cooler; the device also comprises a filter press, a drying and crushing device, a first powder selecting system, a grinding device and a second powder selecting system; the discharge port of the filter press is connected with the feed port of the drying and crushing device, the discharge port of the drying and crushing device is connected with the feed port of the first powder selecting system, the discharge port of the first powder selecting system is connected with the feed port of the preheater, the discharge port of the grinding device is connected with the feed port of the second powder selecting system, and the discharge port of the second powder selecting system is connected with the feed port of the first powder selecting system; according to the invention, the water in the red mud is removed by virtue of the filter press and the drying and crushing device to prepare the red mud dry powder, and meanwhile, the red mud dry powder, the limestone and bauxite blending dry powder and the alkali are uniformly mixed by virtue of the grinding device, and then are fed into the rotary kiln for calcination after passing through the preheater, so that the heat consumption required in the calcination process is greatly reduced, and the production cost is greatly reduced.)

1. An alumina clinker dry calcining system comprises a preheater, a rotary kiln and a grate cooler; the discharge gate of preheater links to each other with the feed inlet of rotary kiln, and the discharge gate of rotary kiln links to each other its characterized in that with the feed inlet of comb formula cooler: the device also comprises a filter press, a drying and crushing device, a first powder selecting system, a grinding device and a second powder selecting system; the discharge port of the filter press is connected with the feed port of the drying and crushing device, the discharge port of the drying and crushing device is connected with the feed port of the first powder selecting system, the discharge port of the first powder selecting system is connected with the feed port of the preheater, the discharge port of the grinding device is connected with the feed port of the second powder selecting system, and the discharge port of the second powder selecting system is connected with the feed port of the first powder selecting system; the high-temperature area air outlet of the grate cooler is connected with the air inlet of the rotary kiln, and the low-temperature area air outlet of the grate cooler is connected with the air inlet of the second powder selecting system; the air outlet of the rotary kiln is connected with the air inlet of the preheater, and the air outlet of the preheater is connected with the air inlet of the drying and crushing device.

2. The alumina clinker dry calcination system according to claim 1, wherein: the hot blast stove is arranged between the grate cooler and the drying and crushing device, an air outlet of the middle temperature area of the grate cooler is connected with an air inlet of the hot blast stove, and an air outlet of the hot blast stove is connected with an air inlet of the drying and crushing device.

3. The alumina clinker dry calcination system according to claim 1, wherein: still include the compounding device, the compounding device is located between first selection powder system and the pre-heater, the discharge gate of compounding device links to each other with the feed inlet of pre-heater, the discharge gate of first selection powder system and second selection powder system all links to each other with the feed inlet of compounding device.

4. The working principle of the alumina clinker dry calcining system is characterized in that: the method comprises the following steps:

(1) the red mud is pre-dehydrated and then fed into a filter press for filter pressing to reduce water content, and then fed into a drying and crushing device to prepare powder, and the powder is fed into a first powder selecting system to select red mud dry powder meeting the fineness requirement.

(2) Limestone and bauxite are fed into a grinding device to be made into powder, and fed into a second powder selecting system to select ingredient dry powder meeting the fineness requirement, and then fed into a first powder selecting system; and introducing low-temperature waste gas in the grate cooler into a second powder selecting system for drying limestone and bauxite.

(3) Feeding powdery alkali into a first powder selecting system to be mixed with red mud dry powder and batching dry powder to form raw material powder, feeding the raw material powder into a preheater to be preheated, feeding the raw material powder into a rotary kiln to be calcined, feeding calcined clinker into a grate cooler to be cooled, and feeding the cooled clinker into a clinker warehouse to be stored; the high-temperature waste gas in the grate cooler returns to the rotary kiln to be used for heating the raw meal.

(4) The medium-temperature waste gas in the grate cooler and the waste gas generated in the rotary kiln and the preheater are all introduced into a drying and crushing device to be used for drying the red mud, whether the waste gas heat output from the preheater meets the requirement of drying the red mud is determined according to the moisture content of the red mud and the hourly feeding amount, and if the waste gas is not enough for drying the red mud, the waste gas temperature can be increased by reducing the heat exchange stages of the preheater to meet the requirement of drying the red mud.

(5) If the red mud dry powder, the batching dry powder and the powdery alkali need to be fully mixed, the materials can be fed into a mixing device to form uniformly mixed raw material powder, and then the raw material powder is fed into a preheater.

(6) If the water content of the red mud is higher after filter pressing, the hot blast stove can be started, so that medium-temperature waste gas generated in the grate cooler enters the hot blast stove to provide oxygen-containing hot air for fuel combustion, the fuel combustion is completed in the hot blast stove, and hot flue gas is formed and enters the drying and crushing device to dry the red mud; when the rotary kiln stops operating, the hot blast stove provides oxygen by air and finishes fuel combustion, and the generated high-temperature flue gas can also independently dry the red mud.

(7) If the alkali is blocky alkali, the blocky alkali, limestone and bauxite can be fed into the grinding device together.

(8) If the content of sulfate in clinker is high, part of coal can be added into bauxite and limestone, and then the mixture powder mixed with coal powder is produced after the grinding device, when the coal powder enters the rotary kiln to be calcined, a reducing atmosphere can be produced in the kiln, and then the generation of sulfate is reduced, so that the alkali consumption is reduced, and the dissolution rate of later-stage alumina clinker is increased.

5. The operating principle of the alumina clinker dry calcination system according to claim 4, wherein: the water content of the red mud powder in the step (1) is less than or equal to 3 percent.

6. The operating principle of the alumina clinker dry calcination system according to claim 4, wherein: the water content of the ingredient powder in the step (2) is less than or equal to 1 percent.

7. The operating principle of the alumina clinker dry calcination system according to claim 4, wherein: and (3) when the low-temperature waste gas in the grate cooler in the step (2) is remained besides the requirement of drying limestone and bauxite, the low-temperature waste gas can be sent into a coal grinding system to dry coal powder.

Technical Field

The invention relates to an alumina clinker dry calcining system and a working principle thereof.

Background

The aluminum oxide preparation currently takes a Bayer process as a main preparation process, the Bayer process has simple preparation process flow and low production cost, but has higher requirements on bauxite, and is suitable for preparing aluminum oxide from bauxite with high aluminum-silicon ratio; along with the development of aluminum industry and the consumption of bauxite, high-quality bauxite required by aluminum oxide is less and less, and domestic aluminum oxide production enterprises have to purchase bauxite with high aluminum-silicon ratio from abroad, so that the production cost is increased; moreover, the foreign high-quality bauxite resources are gradually reduced, the bauxite with low aluminum-silicon ratio has to be considered for preparing the alumina, and the sintering method is a more reasonable method for preparing the alumina clinker by utilizing the bauxite with low aluminum-silicon ratio.

In the Bayer process for preparing alumina, high-moisture red mud is formed by the dissolution of bauxite, and the red mud still contains a certain amount of alumina and alkali content, and can be used as a raw material for producing alumina clinker by recycling.

The existing alumina clinker calcining system is to prepare raw slurry from red mud by a wet grinding mode and then directly feed the raw slurry into a rotary kiln for wet calcining, and because the red mud has higher moisture, the heat consumption of the system in the clinker calcining process is higher, so that the production cost is higher, and in addition, the system has higher failure rate, and is to be further improved.

Disclosure of Invention

In view of the current situation of the prior art, the technical problem to be solved by the present invention is to provide an alumina clinker dry calcination system and a working principle thereof, which can remove moisture in red mud, thereby greatly reducing the heat consumption required in the calcination process and further greatly reducing the production cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: an alumina clinker dry calcining system comprises a preheater, a rotary kiln and a grate cooler; the discharge gate of preheater links to each other with the feed inlet of rotary kiln, and the discharge gate of rotary kiln links to each other its characterized in that with the feed inlet of comb formula cooler: the device also comprises a filter press, a drying and crushing device, a first powder selecting system, a grinding device and a second powder selecting system; the discharge port of the filter press is connected with the feed port of the drying and crushing device, the discharge port of the drying and crushing device is connected with the feed port of the first powder selecting system, the discharge port of the first powder selecting system is connected with the feed port of the preheater, the discharge port of the grinding device is connected with the feed port of the second powder selecting system, and the discharge port of the second powder selecting system is connected with the feed port of the first powder selecting system; the high-temperature area air outlet of the grate cooler is connected with the air inlet of the rotary kiln, and the low-temperature area air outlet of the grate cooler is connected with the air inlet of the second powder selecting system; the air outlet of the rotary kiln is connected with the air inlet of the preheater, and the air outlet of the preheater is connected with the air inlet of the drying and crushing device.

Preferably, the drying and crushing device further comprises a hot blast stove, the hot blast stove is arranged between the grate cooler and the drying and crushing device, an air outlet of the middle temperature area of the grate cooler is connected with an air inlet of the hot blast stove, and an air outlet of the hot blast stove is connected with an air inlet of the drying and crushing device.

Preferably, still include the compounding device, the compounding device is located between first selection powder system and the pre-heater, the discharge gate of compounding device links to each other with the feed inlet of pre-heater, the discharge gate of first selection powder system and second selection powder system all links to each other with the feed inlet of compounding device.

The working principle of the alumina clinker dry calcining system is characterized in that: the method comprises the following steps:

(1) the red mud is pre-dehydrated and then fed into a filter press for filter pressing to reduce water content, and then fed into a drying and crushing device to prepare powder, and the powder is fed into a first powder selecting system to select red mud dry powder meeting the fineness requirement.

(2) Limestone and bauxite are fed into a grinding device to be made into powder, and fed into a second powder selecting system to select ingredient dry powder meeting the fineness requirement, and then fed into a first powder selecting system; and introducing low-temperature waste gas in the grate cooler into a second powder selecting system for drying limestone and bauxite.

(3) Feeding powdery alkali into a first powder selecting system to be mixed with red mud dry powder and batching dry powder to form raw material powder, feeding the raw material powder into a preheater to be preheated, feeding the raw material powder into a rotary kiln to be calcined, feeding calcined clinker into a grate cooler to be cooled, and feeding the cooled clinker into a clinker warehouse to be stored; the high-temperature waste gas in the grate cooler returns to the rotary kiln to be used for heating the raw meal.

(4) The medium-temperature waste gas in the grate cooler and the waste gas generated in the rotary kiln and the preheater are all introduced into a drying and crushing device to be used for drying the red mud, whether the waste gas heat output from the preheater meets the requirement of drying the red mud is determined according to the moisture content of the red mud and the hourly feeding amount, and if the waste gas is not enough for drying the red mud, the waste gas temperature can be increased by reducing the heat exchange stages of the preheater to meet the requirement of drying the red mud.

(5) If the red mud dry powder, the batching dry powder and the powdery alkali need to be fully mixed, the materials can be fed into a mixing device to form uniformly mixed raw material powder, and then the raw material powder is fed into a preheater.

(6) If the water content of the red mud is higher after filter pressing, the hot blast stove can be started, so that medium-temperature waste gas generated in the grate cooler enters the hot blast stove to provide oxygen-containing hot air for fuel combustion, the fuel combustion is completed in the hot blast stove, and hot flue gas is formed and enters the drying and crushing device to dry the red mud; when the rotary kiln stops operating, the hot blast stove provides oxygen by air and finishes fuel combustion, and the generated high-temperature flue gas can also independently dry the red mud.

(7) If the alkali is blocky alkali, the blocky alkali, limestone and bauxite can be fed into the grinding device together.

(8) If the content of sulfate in clinker is high, part of coal can be added into bauxite and limestone, and then the mixture powder mixed with coal powder is produced after the grinding device, when the coal powder enters the rotary kiln to be calcined, a reducing atmosphere can be produced in the kiln, and then the generation of sulfate is reduced, so that the alkali consumption is reduced, and the dissolution rate of later-stage alumina clinker is increased.

Preferably, the water content of the red mud powder in the step (1) is less than or equal to 3%.

Preferably, the water content of the ingredient powder in the step (2) is less than or equal to 1%.

Preferably, when the low-temperature waste gas in the grate cooler in the step (2) is remained besides the requirement of drying limestone and bauxite, the low-temperature waste gas can be sent to a coal grinding system to dry coal powder.

Compared with the prior art, the invention has the advantages that: according to the invention, the water in the red mud is removed by virtue of the filter press and the drying and crushing device to prepare the red mud dry powder, and meanwhile, the red mud dry powder, the limestone and bauxite blending dry powder and the alkali are uniformly mixed by virtue of the grinding device, and then are fed into the rotary kiln for calcination after passing through the preheater, so that the heat consumption required in the calcination process is greatly reduced, and the production cost is greatly reduced.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of the connection between the grate cooler and the second dust separation system according to the present invention;

FIG. 3 is a schematic view of the connection of the mixing apparatus of the present invention;

FIG. 4 is a schematic diagram of the operation of the block alkali of the present invention.

Detailed Description

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

To maintain the following description of the embodiments of the present invention clear and concise, a detailed description of known functions and known components of the invention have been omitted.

As shown in fig. 1 to 4, an alumina clinker dry calcining system comprises a preheater, a rotary kiln and a grate cooler; the discharge hole of the preheater is connected with the feed inlet of the rotary kiln, and the discharge hole of the rotary kiln is connected with the feed inlet of the grate cooler; the method comprises the following steps of drying raw materials, preparing into powder, homogenizing, feeding the raw materials into a preheater to preheat dry raw materials and remove part of crystal water, preheating the raw materials to a temperature above 200 ℃, feeding the raw materials into a rotary kiln to calcine the raw materials to generate clinker, cooling the calcined clinker in a grate cooler, and obtaining red mud as a main product after the raw materials are dissolved; the device also comprises a filter press, a drying and crushing device, a first powder selecting system, a grinding device and a second powder selecting system; the discharge port of the filter press is connected with the feed port of the drying and crushing device, the discharge port of the drying and crushing device is connected with the feed port of the first powder selecting system, the discharge port of the first powder selecting system is connected with the feed port of the preheater, the discharge port of the grinding device is connected with the feed port of the second powder selecting system, and the discharge port of the second powder selecting system is connected with the feed port of the first powder selecting system; the air outlet of the high-temperature area of the grate cooler is connected with the air inlet of the rotary kiln, and the air outlet of the low-temperature area of the grate cooler is connected with the air inlet of the second powder selecting system; the air outlet of the rotary kiln is connected with the air inlet of the preheater, and the air outlet of the preheater is connected with the air inlet of the drying and crushing device.

The utility model provides an aluminium oxide grog dry process calcining system, still includes the hot-blast furnace, and the hot-blast furnace is located between grate cooler and the stoving reducing mechanism, and the middle temperature district air outlet of grate cooler links to each other with the air intake of hot-blast furnace, and the air outlet of hot-blast furnace links to each other with the air intake of stoving reducing mechanism.

The utility model provides an aluminium oxide grog dry process system of calcining, still includes the compounding device, and the compounding device is located between first selection powder system and the pre-heater, and the discharge gate of compounding device links to each other with the feed inlet of pre-heater, and the discharge gate of first selection powder system and second selection powder system all links to each other with the feed inlet of compounding device.

The working principle of the alumina clinker dry calcining system comprises the following steps:

(1) the method comprises the steps of feeding red mud into a filter press after pre-dehydration to reduce the water content, then feeding the red mud into a drying and crushing device to prepare powder with the water content less than or equal to 3%, and finally feeding the powder into a first powder selecting system to select red mud dry powder meeting the fineness requirement.

(2) Limestone and bauxite are fed into a grinding device to prepare powder with the water content less than or equal to 1 percent, the powder is fed into a second powder selecting system to sort out the auxiliary dry powder meeting the fineness requirement, and then the auxiliary dry powder is fed into a first powder selecting system; and introducing low-temperature waste gas in the grate cooler into a second powder selecting system for drying limestone and bauxite.

(3) Feeding powdery alkali into a first powder selecting system to be mixed with red mud dry powder and batching dry powder to form raw material powder, feeding the raw material powder into a preheater to be preheated, feeding the raw material powder into a rotary kiln to be calcined, feeding calcined clinker into a grate cooler to be cooled, and feeding the cooled clinker into a clinker warehouse to be stored; the high-temperature waste gas in the grate cooler returns to the rotary kiln to be used for heating the raw meal.

(4) The medium-temperature waste gas in the grate cooler and the waste gas generated in the rotary kiln and the preheater are all introduced into a drying and crushing device for drying the red mud, and whether the heat of the waste gas output from the preheater meets the requirement of drying the red mud is determined according to the moisture content of the red mud and the hourly feeding amount, and if the waste gas is not enough for drying the red mud, the temperature of the waste gas can be increased by reducing the heat exchange stages of the preheater so as to meet the requirement of drying the red mud; when the moisture content of the limestone and the bauxite is not high and the low-temperature waste gas in the grate cooler is remained besides the requirement of drying the limestone and the bauxite, part of the low-temperature waste gas can be sent into a coal grinding system to dry the coal powder, so that fuel with less moisture is provided for the rotary kiln, and the heating speed of the rotary kiln is increased.

(5) If the red mud dry powder, the batching dry powder and the powdery alkali need to be fully mixed, the materials can be fed into a mixing device to form uniformly mixed raw material powder, and then the raw material powder is fed into a preheater.

(6) If the water content of the red mud is higher after filter pressing, the hot blast stove can be started, so that medium-temperature waste gas generated in the grate cooler enters the hot blast stove to provide oxygen-containing hot air for fuel combustion, the fuel combustion is completed in the hot blast stove, and hot flue gas is formed and enters the drying and crushing device to dry the red mud; when the rotary kiln stops operating, the hot blast stove provides oxygen by air and finishes fuel combustion, and the generated high-temperature flue gas can also independently dry the red mud.

(7) If the alkali is blocky alkali, the blocky alkali, limestone and bauxite can be fed into the grinding device together.

(8) If the content of sulfate in clinker is high, part of coal (such as anthracite which is difficult to burn) can be added into bauxite and limestone, and then the mixture powder mixed with coal powder is generated after a grinding device, when the coal powder enters a rotary kiln to be calcined, a reducing atmosphere is generated in the kiln, and then the generation of sulfate is reduced, so that the alkali consumption is reduced, and the dissolution rate of later-stage alumina clinker is improved.

According to the invention, the water in the red mud is removed by virtue of the filter press and the drying and crushing device to prepare the red mud dry powder, and meanwhile, the red mud dry powder, the limestone and bauxite blending dry powder and the alkali are uniformly mixed by virtue of the grinding device, and then are fed into the rotary kiln for calcination after passing through the preheater, so that the heat consumption required in the calcination process is greatly reduced, and the production cost is greatly reduced.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes in the embodiments and modifications thereof may be made, and equivalents may be substituted for elements thereof; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.