WO2012108148A1

WO2012108148A1 - Calcium-oxide-containing burned product, consumed product of same, and method for manufacturing calcium-oxide-containing burned product

Info

Publication number: WO2012108148A1
Application number: PCT/JP2012/000686
Authority: WO
Inventors: 赤見　昌彦
Original assignee: 株式会社赤見製作所
Priority date: 2011-02-08
Filing date: 2012-02-01
Publication date: 2012-08-16
Also published as: JP2014076908A

Abstract

A particulate or finely processed product containing a lime component is made into a high-quality product having a low unreacted calcareous substance content and a high specific surface area. A processed product containing a lime component and having a size not in excess of 5 mm comprises one or more calcareous feedstocks among limestone, slaked lime, and by-product lime; and an auxiliary feedstock admixed according to need, the processed product being calcined at 400 to 1200°C using a heat-treatment device comprising a furnace tube for heating the processed product, and beater members provided within the furnace tube. The beater members are provided in a plurality of columns along the direction of the center axis of the furnace tube, the rotation of the furnace tube causing the beater members to roll over the inside surface of the furnace tube, and impart shock to the processed product. The processed product comprises 60 to 99 wt% of CaO, 0.1 to 5 wt% of a carbonate (expressed in terms of CO₂), 0.01 to 20 wt% of Al₂O₃, and 0.01 to 20 wt% of SiO₂, while having a hydration activity of 0.5 to 60 seconds, and a BET specific surface area of 3 m²/g or higher.

Description

Burned product containing quicklime, digested product thereof, and method for producing burned product containing quicklime

The present invention relates to a calcined lime-containing calcined product obtained by calcining a processed product containing a lime component, a digested product thereof, and a method for producing the calcined lime-containing calcined product.

Generally, lime (limestone, quicklime, slaked lime, calcium carbonate) is used in various fields such as architecture / civil engineering, chemistry, papermaking, food, and environment.

In the production process of these limes, various by-products containing calcareous components, so-called by-product lime, are generated in various forms. For example, fine limestone / limestone powder generated during limestone crushing and refining processes, washing residue / dehydrated cake, fine dust / baked dust generated during the production of quicklime, and heavy / light calcium carbonate Examples include limestone powder, wet residue / dehydrated cake, wet residue / dehydrated cake generated in the manufacturing process of slaked lime, or calcareous process by-products generated in the manufacturing process of paper, sugar, and leather.

Since fine lime and fine lime have problems in handling, its use is limited, and it is difficult to find a useful use especially with fine lime of 1 mm or less. Furthermore, the by-product lime is not only fine and fine, but often contains inorganic and organic components and moisture other than calcareous, making it difficult to handle as well as effectively. . In addition, the cost for recycling these by-product lime is much higher than the cost of processing and producing a high-quality lime raw material, which is a barrier to effective use.

As a method of using fine lime and fine lime, these can be calcined to obtain a calcined product containing quick lime, but in the existing vertical furnace (shaft kiln, vertical kiln), ventilation in the furnace must be ensured. In this respect, the minimum particle size of the raw material is usually required to be about 20 mm, and it is practically impossible to burn fine particles / fine lime in a vertical furnace.

Conventionally, for example, a technique described in Japanese Patent Application Laid-Open No. 06-9263 (Patent Document 1) is known as a method for firing such fine particles and fine lime. In this method, fine crystalline, medium crystalline or higher limestone is pulverized, and the obtained limestone powder is formed into a predetermined size and then fired at 900 ° C. or higher.
Conventionally, for example, a technique described in Japanese Patent Application Laid-Open No. 2009-114029 (Patent Document 2) is also known. This is a process of firing lime sludge mixed with washing sludge discharged in the process of washing the mined limestone and dust collected from the exhaust gas of the lime firing furnace. It has the granulation process which granulates the lime sludge after a process in a defined shape, and the baking process which bakes the granulated lime sludge. In the drying process, the moisture of the lime sludge is dried to 16% by weight or less, and in the firing process, a rotary kiln having a condition that the temperature of the raw material inlet is 650 ° C. or less is used.

On the other hand, in the manufacture of kraft pulp, when preparing sodium hydroxide used in the causticizing process, a process for digesting quick lime to make slaked lime, a reaction between slaked lime and sodium carbonate to use in the causticizing process A circulation system for calcareous raw materials has been constructed which comprises a step of recovering sodium oxide and a step of calcining lime mud mainly composed of calcium carbonate, which is a by-product of the above reaction, to produce quick lime. Since this lime mud has a high water content and contains fine and fine calcium carbonate, when it is fired, it is difficult to handle due to its high adhesion, and its thermal efficiency is low. Processed material that adheres to the firing furnace falls, and the fallen product forms a lump, resulting in uneven baking of the fired product, stable firing due to adhesion in the furnace and the occurrence of lump. There are various problems such as inability to do so.

In order to solve these problems, for example, in Japanese Patent Laid-Open No. 2000-256045 (Patent Document 3), lime mud is dried by a fluidized dryer in which a fluidized bed is formed with a granular fluidized medium, and then the dried product is There is shown a method and apparatus for calcining lime mud that is calcined by a fluidized calciner in which a fluidized bed is formed with a granular fluidized medium to form quicklime.
Further, in JP-A-2005-180803 (Patent Document 4), it can be rotationally driven, and has a cylindrical main body having an input part at one end and a discharge part at the other end, and combustion gas from the other end to the cylindrical main body. In a rotary baking apparatus equipped with a combustion burner to be introduced, a rotation in which a spiral lifter and a parallel lifter parallel to the shaft center are arranged on the inner periphery of one end of the cylindrical main body from one end side to the other end side A combustion apparatus is shown.

Furthermore, the papermaking sludge generated in the papermaking process also contains calcareous, is fine and fine, and has a high water content, as described above, it is difficult to handle, dry and fire. In addition, since papermaking sludge contains various components such as silica, alumina, and pulp, in addition to calcium carbonate, there is a problem that it is difficult to reuse the dried product and the fired product.

Japanese Patent Laid-Open No. 06-9263 JP 2009-114029 A Japanese Patent Laid-Open No. 2000-256045 JP 2005-180803 A

By the way, in the conventional baking method of the said patent document 1, although a baking means is not clear, since the shaping | molding process of a limestone powder is essential, there exists a problem that equipment cost is bulky and manufacturing cost is high. .
Moreover, in the conventional baking method of the said patent document 2, since the rotary kiln is used, when a short path | pass tends to generate | occur | produce a to-be-fired object, when a short path | pass generate | occur | produces, decarbonation is fully performed to a baked product. No so-called unreacted lime remains, and there is a problem that the activity is insufficient and the quality is poor. Moreover, in this prior art, since the shaping | molding process of a lime sludge is essential, there also exists a problem that equipment cost is bulky and manufacturing cost is high. If lime sludge is put into a rotary kiln as it is without being formed, fine particles and fine lime are highly adherent and cause a problem that a coating is easily formed on the inner wall of the furnace during firing. Therefore, there is a problem in that it is difficult to directly process a processed product having a size of lime as a main component and having a size of 5 mm or less to obtain a high-quality quicklime-containing fired product.

On the other hand, in the conventional firing method of Patent Document 3 described above, since the object to be treated is dried and fired in a fluidized state, compared with firing by a generally known rotary kiln, improvement in thermal efficiency and homogeneity of the fired product. Benefits such as improvement are expected. However, there is a problem that the equipment cost is increased and the manufacturing cost is increased in that a dedicated drying furnace is essential for drying the lime mud. Furthermore, since there is no countermeasure against the adherence of the object to be treated to the inner wall of the fluidized drying furnace and the fluidized baking furnace, there is a risk that the object to be treated in a fluid state will form an adhering substance on the inner wall of the furnace. .
Moreover, in the conventional baking method of patent document 4, since the two lifters, the spiral lifter and the parallel lifter, are disposed inside the cylindrical main body, the workpiece is forcibly scraped and stirred. As compared with a firing furnace in which no lifter is provided, improvement in thermal efficiency and improvement in homogeneity of the fired product are expected. However, even in this baking apparatus and baking method, there is no concern about the adherence of the object to be processed to the inside of the cylindrical main body. In particular, the lifter has a function of holding the object to be processed until the object to be processed placed on the lifter falls by gravity during the rotational movement of the cylindrical main body. Since the agitation is performed, deposits are formed in the space between the inner wall of the cylindrical main body and the lifter during the firing process, and as a result, the risk that the lifter will not function as a lifter is considered to be extremely high.

The present invention has been made in view of such problems, and has a lime component-containing fine particle / fine processed product having a size of 5 mm or less, or a lime component, which is fine / fine and water-containing. The processed product in a state is directly calcined by a heat treatment apparatus, avoiding adhesion to the furnace, and having a low unreacted calcareous content and a high quality excellent calcined lime-containing calcined product with a high specific surface area, It aims at providing the manufacturing method of the high-quality slaked lime and quicklime containing calcination thing provided with the high reactivity and specific surface area which are the digests.

In order to achieve such an object, the calcined lime-containing calcined product of the present invention is a calcined lime-containing calcined product obtained by calcining a treated product having a size of lime as a component of 5 mm or less,
As said processed material, it comprises any one or more calcareous raw materials among limestone, slaked lime and byproduct lime, and auxiliary raw materials blended as necessary,
A furnace core tube for heating the processed material, and a plurality of rows are provided along the direction of the central axis of the furnace core tube provided in the furnace core tube, and the inner periphery of the furnace core tube is rotated by the rotation of the furnace core tube. The processed product is fired in the range of 400 ° C. to 1200 ° C. by a heat treatment apparatus including a beater member that rolls the surface and imparts an impact to the processed product.
It contains 60 to 99% by weight of CaO and 0.1 to 5% by weight of carbonate (CO ₂ equivalent value), has a hydration activity of 0.5 to 60 seconds, and a BET specific surface area of 3 m ² / g or more. It is configured. The carbonate (CO ₂ equivalent value) means the content of CO ₂ contained in the target product, and is mainly derived from unreacted calcium carbonate.

The above-described invention is intended for a processed product mainly composed of lime, but constitutes a furnace core tube for heating the processed product, and the furnace core tube provided in the furnace core tube. Heat treatment is performed by a heat treatment apparatus provided with a beater member that is arranged in plural along the central axis and rolls on the inner peripheral surface of the furnace core tube by the rotation of the furnace core tube to give an impact to the processed material. As a result, a burned product containing quick lime having a relatively high BET specific surface area, that is, a relatively high activity, can be obtained even in a processed product having a low lime content.
That is, another calcined lime-containing fired product of the present invention is a calcined lime-containing fired product obtained by firing a treated product containing a lime component having a size of 5 mm or less. It is composed of any one or more calcareous raw materials of lime and auxiliary raw materials blended as necessary, and a furnace core tube for heating the processed material, and provided in the furnace core tube, A heat treatment apparatus provided with a beater member that is arranged in a plurality along the direction of the central axis and rolls on the inner peripheral surface of the furnace core tube by the rotation of the furnace core tube to give an impact to the processed material The above-mentioned treated product is fired in the range of 400 ° C. to 1200 ° C., CaO is 15 to 60% by weight, Al ₂ O ₃ is 10 to 50% by weight, SiO ₂ is 15 to 50% by weight, carbonate (CO ₂ equivalent) Value) 0.1 to 5% by weight and a BET ratio table The product has a configuration which is more than 1 m 2 ^{/ g.}

According to the present invention, a fine and fine processed product having a lime component size of 5 mm or less is directly baked by a heat treatment apparatus, the content of unreacted calcareous material is small, and a high specific surface area is provided. A calcined lime-containing fired product with excellent quality can be provided. Depending on the calcined lime-containing fired product, a product exhibiting particularly high hydration activity is produced. Furthermore, the present invention can provide a high quality and excellent slaked lime-containing digested product having high reactivity and specific surface area. Furthermore, while avoiding the adhesion of the treated product to the furnace, the content of the unreacted treated product can be reduced to obtain a high-quality fired product, and the product recovery rate can be improved. A method for producing a calcined lime-containing fired product can be provided.

It is a figure which shows an example of the heat processing apparatus for baking the quicklime containing baking products which concern on embodiment of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 showing a heat treatment apparatus for firing the calcined lime-containing fired product according to the embodiment of the present invention. It is sectional drawing which shows the principal part of the heat processing apparatus for baking the quicklime containing baking products which concern on embodiment of this invention. It is a table | surface figure which shows the baking raw material used in the Example and comparative example of this invention. FIG. 3 is a table showing the firing conditions, the state of adhesion of the fired product in the furnace, the recovery rate of the fired product, and the properties of the fired product of Examples 1 to 18 of the present invention. FIG. 15 is a table showing firing conditions, comparative examples 1 to 15 showing the firing conditions, the state of adherence of the fired products in the furnace, the recovery rate of the fired products, and the properties of the fired products. It is a table | surface figure which shows the result of the moisture absorption test in the constant temperature and humidity of Examples 20 and 20 of this invention and Comparative Examples 16 and 17 and the quicklime containing baking products packaged with the packaging material. FIG. 6 is a table showing the properties of quick calcined lime-containing fired products by slaked lime according to Examples 21 to 24 and Comparative Examples 18 and 19 of the present invention.

Hereinafter, the calcined lime-containing fired product according to the embodiment of the present invention will be described with reference to the accompanying drawings.
The calcined lime-containing fired product according to the embodiment is obtained by firing a treated product containing a lime component and having a size of 5 mm or less.
As a processed material, any one or more calcareous materials among limestone, slaked lime, and byproduct lime having a size of 5 mm or less are used as essential materials. Here, the calcareous raw material does not limit the kind or properties of the calcareous raw material, and only the size is 5 mm or less.

By-product lime refers to calcareous by-products generated during the manufacture of lime products and calcareous process by-products generated during the processing of various industrial products and foods, especially when manufacturing limestone, calcium carbonate, quicklime, and slaked lime. Used for the purpose of refining sugar in the sugar-making process. The calcareous by-products and the like originating from lime are particularly recommended by-product lime in that they are fine. In addition, among the by-product lime, dehydrated cake, wet residue, or lime mud has a high moisture content and strong adhesion, so that it is considered a highly difficult treatment not only for handling but also for heat treatment, In the present invention, since the moisture content of the treated product does not have an adverse effect on the stability of firing and the quality of the fired product, the above-mentioned hydrous treated product is also a particularly recommended byproduct lime.

Further, crystalline limestone having a size of 5 mm or less is also suitable as a limestone raw material used in the present invention. Crystalline limestone has the characteristic of self-disintegrating and pulverizing in the firing process, because this characteristic matches the characteristics of a heat treatment apparatus described later that is effective for firing fine raw materials. These by-product lime or fine crystalline limestone has little useful use and is often discarded. Therefore, the use of by-product lime and fine crystalline limestone is particularly recommended from the viewpoint of reducing the amount of waste and effective utilization of unused and difficult-to-use resources.

Furthermore, in addition to the calcareous raw material, an auxiliary raw material may be blended depending on the use of the product on the assumption that the chemical component of the calcined lime-containing fired product defined in the present invention is satisfied. For example, when the calcined lime-containing fired product of the present invention is used as a refining agent for steelmaking, a refining effect is achieved when components such as aluminum oxide, silicon oxide, magnesium oxide, or an oxide containing an alkali metal having a function as a flux coexist. Therefore, it is reasonable to subject the auxiliary raw material containing these oxides to calcining together with calcareous raw material from the viewpoints of simplifying the production process, reducing the calorific value, and reducing the amount of CO ₂ generated. . In addition, when using the burned product containing quick lime of the present invention as it is or digested and containing slaked lime as an exhaust gas treatment agent, a certain amount of lime, which is the main target component, is secured. In addition, it is preferable to suppress the blending of the auxiliary materials. Thus, the auxiliary raw material may be appropriately selected according to the purpose of use of the product, and is not particularly limited in its type and properties, but the calcined lime-containing fired product according to the present invention is used as, for example, the above-described steel refining agent. When used, steel slag, coal ash, aluminum ash, paper sludge, etc. are recommended as auxiliary raw materials from the viewpoint of effective utilization of unused and difficult-to-use resources.

Note that the calcareous raw material and the auxiliary raw material to be used for firing may be either in a dry state or in a wet state. Needless to say, from the viewpoint of heat consumption, the dry state is preferable, but the heat treatment apparatus described below is used for the treatment of the object to be treated on the inner wall of the furnace, which is a concern in drying and firing in a normal internal-heated rotary furnace or external-heated rotary furnace. Adhesion and coagulation of the processed product do not occur, so that it may be put into the furnace in a wet state. In other words, the drying step can be omitted by putting the water-washed / dehydrated cake generated in the limestone refining step into the heat treatment apparatus in a wet state.
Furthermore, adding other additives in addition to the above-mentioned auxiliary materials does not hinder the present invention. In particular, combustible materials such as pulverized coal, waste plastic, heavy oil, and waste oil burn in the furnace and provide an effective amount of heat for the dehydration and decarboxylation reactions of the material to be baked. This is useful as a measure to suppress it.

In addition, as will be described later, the calcined lime-containing fired product of the present invention is directed to high hydration activity, high specific surface area, that is, high activity, but does not require activity, in other words, civil engineering / architecture applications that require hard firing. When the calcined lime-containing fired product of the present invention is applied to agricultural or agricultural applications, the specific surface area (activity of the calcined lime-containing calcined product obtained by selecting the quality of calcareous raw materials or adjusting the amount of auxiliary raw materials is adjusted. ) May be controlled. That is, it is possible to actively utilize difficult-to-use low-grade lime (low-purity limestone), by-product lime, or by-product raw materials according to the purpose of use of the product.

Further, in the embodiment, the processed product may include a calcined lime-containing fired product recovered as a product from a heat treatment apparatus to be described later and / or a recovered product other than the product discharged from the heat treatment apparatus.
Here, the recovered material other than the product is, for example, cyclone dust / bag filter dust recovered from the raw material feeding device or the product recovery device, or the processed material leaked out of the system without being charged into the heat treatment device in the handling of the processed material. Or, a defective product whose quality has not been achieved or a switching product which is generated during the continuous production of different types of products. Adding these products that cannot be used as products to the treated products and subjecting them again to heat treatment is not only effective in improving the product recovery rate, but also when the moisture content of the treated products is relatively high, Bring.

In other words, processed products with a high water content are likely to cause troubles in handling such as adhesion and blockage in the transportation route, or instability of the inflow amount accompanying them, but they are recovered as products from the above heat treatment equipment. Since the quick lime-containing fired product and the recovered product other than the product discharged from the heat treatment apparatus are in a dry state, the moisture content of the treated product is relatively reduced by adding them to the treated product having a high moisture content, As a result, handling trouble can be suppressed. In particular, the switching that occurs during the continuous production of burnt lime containing burnt lime recovered as a product from the above heat treatment equipment, cyclodust / bag filter dust recovered from the product recovery equipment, defective products of unachieved quality and different products The product contains quicklime, and in the process that this quicklime component reacts with the moisture contained in the processed product to produce slaked lime, the generation of digestion heat, the evaporation of water due to digestion heat, the temperature of the processed product due to digestion heat A phenomenon such as an increase occurs, and as a result, effects such as a reduction in the moisture content of the processed product and a reduction in the calorific value of the heat treatment apparatus are exhibited.

Further, in the embodiment, the processed material forms a premixed mixture before being supplied to the heat treatment apparatus, and water, caking components are included in the mixture as necessary. You may add and mix the aqueous solution and / or suspension containing this. Since the formation of the mixture increases the homogeneity of the entire processed product, the above effects such as improvement of the product recovery rate and reduction of the moisture content of the processed product are exhibited to a higher degree. In addition, if necessary, water and an aqueous solution and / or suspension containing a caking component are added to and mixed with this mixture, and fine powder that is likely to fly out of the furnace is granulated. As a result, the product recovery rate is improved. Here, the caking component is not particularly limited as long as it is effective for the formation of the desired granulated body, such as organic substances such as higher alcohol, methylcellulose and polyvinyl alcohol, or sodium silicate and bentonite. Various things such as inorganic substances can be used.

The calcined lime-containing fired product according to the embodiment of the present invention is manufactured by a heat treatment apparatus. With this heat treatment apparatus, the treated product is fired in the range of 400 ° C. to 1200 ° C., CaO is 60 to 99% by weight, carbonate (CO ₂ conversion value) is 0.1 to 5% by weight, and Al ₂ O ₃ is 0%. A calcined calcined product containing 0.01 to 20% by weight, 0.01 to 20% by weight of SiO ₂ , a hydration activity of 0.5 to 60 seconds, and a BET specific surface area of 3 m ² / g or more is obtained.
In addition, the calcined lime-containing fired product according to another embodiment of the present invention is obtained by firing the treated product in a range of 400 ° C. to 1200 ° C. with a heat treatment apparatus, CaO 15 to 60% by weight, carbonate (CO ₂ equivalent) Value) 0.1-5% by weight, Al ₂ O ₃ 10-50% by weight, SiO ₂ 15-50% by weight and a BET specific surface area of 1 m ² / g or more, To do.
Two types of heat treatment apparatuses are used: a co-current type heat treatment apparatus for flowing air in the furnace in the same direction as the treatment object, and a countercurrent heat treatment apparatus for flowing air in the furnace in the opposite direction to the treatment object. It is done.

1 to 3 show a parallel flow heat treatment apparatus S for carrying out a manufacturing method according to an embodiment of the present invention. This includes a processed product supply unit 1 for supplying a processed product W. The processed product supply unit 1 includes a hopper 2 that stores the processed product W, and a screw conveyor 3 that conveys the processed product W in the hopper 2 to an upstream end side of a furnace core tube 10 to be described later. The screw conveyor 3 is driven via a transmission mechanism including a sprocket 5 and a chain 6 that are rotated by a motor 4.

Further, the heat treatment apparatus S includes a furnace core tube 10. The furnace core tube 10 includes a supply port 10a that receives the processed product W supplied from the processed product supply unit 1 on the upstream side, and includes a discharge port 7 that discharges the processed product W on the downstream side, and extends in a substantially horizontal direction. The processed product W is rotated about the central axis Pa to move the processed product W from the upstream side to the downstream side, and the processed product is discharged from the discharge port 7. The supply port 10 a is configured at the upstream end of the furnace core tube 10. The downstream end of the furnace core tube 10 is configured as an exhaust port 10b for exhausting gas generated in the furnace core tube.

Outer rings 11 are fixed to the upstream outer side portion of the furnace core tube 10 and the downstream outer side portion behind the discharge port 7 respectively. The outer ring 11 is supported by a roller 13 provided on a frame 12 provided on the installation floor surface, so that the furnace core tube 10 can be rotated via the roller 13 and the outer ring 11. . The furnace core tube 10 is supported while being inclined downward from the supply port 10a side to the exhaust port 10b side, and moves the workpiece W from the supply port 10a side to the exhaust port 10b side by rotation.

As shown in FIG. 3, the discharge port 7 is provided in a wall portion of the furnace core tube 10 on the downstream side of a predetermined section heated by a furnace core tube heating unit 40 described later. More specifically, three discharge ports 7 are provided in an equiangular relationship between the downstream end portion of the heat retaining tube 42 of the furnace core tube heating unit 40 to be described later and the downstream outer ring 11. The furnace core tube 10 is made of heat-resistant steel containing nickel and chromium in order to improve heat resistance and increase durability.

In the furnace core tube 10, a plurality of rows are provided along the direction of the central axis Pa of the furnace core tube 10, and the inner peripheral surface of the furnace core tube 10 is rolled by the rotation of the furnace core tube 10. A beater member 20 for applying an impact to W is provided. The beater member 20 is formed of the same material as the furnace core tube 10, has an axis Pb that is eccentric with respect to the center axis Pa of the furnace core tube 10, is provided radially around the axis Pb, and has an outer edge. Three or more (three in the embodiment) rectangular plate-shaped fins 21 that are in contact with the inner peripheral surface of the furnace core tube 10 are provided.

As shown in FIG. 2, the fins 21 are integrally joined at one side edge so as to be equiangularly spaced, and a circle whose radius is the other side edge of the fin 21 from the center is formed on the core tube 10. It is set slightly smaller than a circle having a radius from the central axis to the inner peripheral surface. When the furnace core tube 10 rotates in the rotation direction R shown in FIG. 2, the beater member 20 falls down and rotates. Of the three fins 21, the other side edge of the two fins 21 is inside the furnace core tube 10. The remaining fins 21 are in contact with the peripheral surface and are upright in the internal space of the furnace core tube 10. As the furnace core tube 10 rotates, the two fins 21 that are in contact with the inner peripheral surface of the furnace core tube 10 also rotate along with the rotation of the one fin 21 that stands upright in the internal space due to its own weight. And one of the other two fins 21 separates from the inner peripheral surface and stands upright in the internal space. A stopper (not shown) is provided in front of the discharge port 7 of the furnace core tube 10 to restrict the movement of the beater member 20 located on the discharge port 7 side to the downstream side.

Moreover, the heat treatment apparatus S includes a drive unit 30 that rotationally drives the furnace core tube 10. The drive unit 30 is stretched over a motor 31, a driving sprocket 32 rotated by the motor 31, a driven sprocket 33 provided outside the supply port 10 a of the furnace core tube 10, and the driving sprocket 32 and the driven sprocket 33. The transmission mechanism is composed of a chain 34.

Furthermore, the heat treatment apparatus S includes a furnace core tube heating unit 40 that heats a predetermined section upstream from the discharge port 7 of the furnace core tube 10 from the outside. The furnace core tube heating unit 40 is provided inside the insulation tube 42, which is provided in the insulation tube 42, which is provided on the gantry 41 and made of a heat insulating member surrounding the furnace core tube 10. And a heater 43 that heats the heater. The code | symbol 42a is the obstruction | occlusion wall which plugs up the edge part of a heat retention tube.

Furthermore, the heat treatment apparatus S is provided with a temperature holding means K that holds the processed product W heated by the furnace core tube heating unit 40 at a predetermined holding temperature until reaching the discharge port 7. The holding temperature held by the temperature holding means K is within the firing temperature range of the workpiece W by heating in the furnace core tube heating unit 40. The temperature holding means K includes a heat insulating material 46 that covers the wall portion of the furnace core tube 10 provided with the discharge port 7. The heat insulating material 46 is made of an appropriate material so that it can be maintained at the above holding temperature, passes through the downstream end of the heat insulating tube 42 of the furnace core tube heating unit 40, and reaches the outer ring 11 on the downstream side. The furnace core tube 10 is coated with a predetermined thickness. The upstream side of the heat insulating material 46 is provided so as to be slidably contacted with the closed wall 42 a of the heat insulating tube 42. As shown in FIG. 3, a through hole 47 having the same size as the discharge port 7 is formed in a portion corresponding to the discharge port 7 of the heat insulating material 46, and a metal tube 47 a is inserted into the through hole 47. Has been.

Further, an intermediate cover 48 that covers the furnace core tube 10 in which the discharge port 7 is formed is provided between the downstream end of the heat insulation tube 42 of the furnace core tube heating unit 40 and the outer ring 11 on the downstream side. Yes. An outlet 49 is provided below the intermediate cover 48 to take out the processed product W discharged from the discharge port 7 of the furnace core tube 10. The take-out port 49 is provided with a valve (not shown) so that the processed product W can be taken out by a predetermined amount.

Furthermore, the heat treatment apparatus S includes an air supply unit 50 that supplies air from the upstream side to the downstream side in the furnace core tube 10. Specifically, in the heat treatment apparatus S, an upstream end cover 51 that covers the supply port 10 a while allowing the furnace core tube 10 to rotate and a downstream end cover 52 that covers the exhaust port 10 b of the furnace core tube 10 are provided. .
The upstream end cover 51 is provided with an air supply port 56 for supplying air into the furnace core tube 10, and the air supply unit 50 is configured to supply air from the air supply port 56. In the upstream end cover portion 51, the screw conveyor 3 of the processed product supply portion 1 is disposed so as to penetrate therethrough.
On the other hand, an exhaust outlet 53 for exhausting exhaust gas exhausted from the exhaust port 10 b of the furnace core tube 10 is provided at the upper part of the downstream end cover portion 52. An exhaust pipe (not shown) is connected to the exhaust outlet 53, and the exhaust is discharged to the outside air through, for example, a cyclone, a wet scrubber, and a bag filter.

Further, on the downstream side of the discharge port 7 of the furnace core tube 10, there is a spiral 57 that returns the processed material W that slides along the wall portion of the furnace core tube 10 and reaches the downstream side beyond the discharge port 7 to the discharge port 7 side. Is provided. The spiral 57 is fixed to the downstream end cover 52 via a shaft body 58. On the other hand, on the supply port 10a side of the furnace core tube 10, a spiral 59 for sending the received processed product W to the downstream side is provided. In the present embodiment, the spiral 59 is fixed to the downstream end cover portion 52 via the shaft body 58 so as to be in sliding contact with the wall portion of the furnace core tube 10, but is not necessarily limited thereto. Instead of being fixed to the shaft body, it may be directly fixed to the wall portion of the furnace core tube 10 by welding or the like, and may be appropriately changed.

In the heat treatment apparatus S, the motor 4 of the processed product supply unit 1, the motor 31 of the drive unit 30, the heater 43 and the air supply unit 50 of the furnace core tube heating unit 40 are controlled, A controller 60 is provided for controlling the rotation of the furnace core tube 10, the temperature of the furnace core tube 10, and the temperature of the exhaust port 10b. The control part 60 is implement | achieved by functions, such as CPU of a computer, for example, and the baking temperature of the furnace core tube 10 is suitably set according to the property of the processed material thrown in. That is, when the calcareous raw material is only calcium hydroxide, a firing temperature of 400 to 800 ° C. is recommended. When the calcareous material contains calcium carbonate, the firing temperature is preferably 800 to 1200 ° C.

In the embodiment, the control unit 60 sets the temperature in the furnace core tube 10 to 800 ° C. to 1200 ° C. In said setting, when calcium carbonate is contained in a calcareous raw material, if the temperature in the furnace core tube 10 is less than 800 degreeC, the thermal decomposition of the processed material W will become inadequate. When the temperature in the furnace core tube 10 exceeds 1200 ° C., high-temperature oxidation of the furnace core tube 10 proceeds, and the durability is significantly adversely affected. More desirably, the temperature in the furnace core tube 10 is set to 850 ° C. to 1050 ° C.

Therefore, when the workpiece W is processed in the cocurrent flow type heat treatment apparatus S according to the embodiment, it is as follows. The drive unit 30, the furnace core tube heating unit 40, and the air supply unit 50 are operated with the required setting by the control unit 60. Thereby, the furnace core tube 10 rotates, and the beater member 20 rotates in the same direction as the rotation direction of the furnace core tube 10 to roll the inner surface of the furnace core tube 10. And if the processed material W is supplied to the supply port 10a of the furnace core tube 10 from the processed material supply part 1, the processed material W will move gradually in the furnace core tube 10, and the processed material W will be heated in this movement. The By this heating, the processed product W is thermally decomposed, discharged as a burned lime-containing fired product from the discharge port 7 of the furnace core tube 10, and taken out from the outlet 54. In this case, on the downstream side of the discharge port 7 of the furnace core tube, a spiral 57 that returns the processed material W that slides along the wall of the furnace core tube 10 and reaches the downstream side beyond the discharge port 7 to the discharge port 7 side. Since it is provided, even if there is a processed product W that is about to reach the downstream side beyond the discharge port 7, the processed product W is returned to the discharge port 7 side from the spiral 57, so that it is surely discharged from the discharge port 7. Can do.

During the heat treatment of the workpiece W, even if the workpiece W adheres to the inner peripheral surface of the furnace core tube 10 and stops, the beater member 20 rotates in the same direction as the rotation direction of the furnace core tube 10. Since the inner surface of the core tube 10 is rolled to give an impact to the processed product W, the processed product W which is attached to the inner peripheral surface of the furnace core tube 10 and is to be retained is caused by the impact to the inner periphery of the furnace core tube 10. It is forced to leave the surface and dispersed. In this case, since the beater member 20 includes the fins 21, when the beater member 20 rolls, the fins 21 collide with the workpiece W, so that the workpiece W is divided. The vibration can be imparted to and dispersed, and firing is reliably performed.

Further, in the furnace core tube 10, when calcareous raw material and auxiliary raw material are fired, dehydration and decarboxylation reactions occur. Water and carbon dioxide gas generated during these reactions are discharged from the exhaust outlet 10 a and the exhaust outlet 53 by an air flow. It is exhausted. In this case, when the ventilation is in the opposite direction (counterflow) with the processed product W, the processed product W scatters on the upstream side of the processed product input side, and as a result, the product recovery rate tends to decrease. In this invention, since the ventilation direction was made into the same direction (parallel flow) as the conveyance direction of the processed material W, the situation where the processed material W scatters to an upstream side can be prevented. Therefore, the recovery rate can be improved.

Further, in the furnace core tube 10, when calcareous raw materials and auxiliary raw materials are baked, dehydration and decarboxylation reactions occur, and the moisture and carbon dioxide gas generated during these reactions are “cocurrent” with the processed material W. The water and carbon dioxide gas generated by the above reaction tends to be reabsorbed by the object to be fired as compared with the countercurrent, but in the embodiment, it is fired in the furnace core tube 10 by the temperature holding means K. Until the processed product W reaches the discharge port 7, the processed product W is held at a holding temperature within the firing temperature range. It is possible to suppress the occurrence of reabsorption reaction. That is, since the temperature of the discharge port 7 and its surroundings (outlet temperature) is maintained at 800 ° C. to 1200 ° C., the temperature becomes less than 800 ° C. at the front of the discharge port 7, and the carbon dioxide gas is reabsorbed in the processed product W. Can be prevented. In short, a situation in which a reaction of CaO + CO ₂ → CaCO ₃ occurs is prevented, and a situation in which the content of quicklime in the product is prevented.

In the above embodiment, at least one of the upstream side of the furnace core tube 10, the supply path of the processed material W until the processed material W is introduced to the furnace core tube 10, and the supply equipment of the processed material W In addition, any one or more of water and an aqueous solution / suspension containing a caking component may be added. If water, an aqueous solution and / or suspension containing a caking component are added at the above location, fine powder that easily scatters outside the furnace is granulated and the scatterability is suppressed, resulting in a product recovery rate. The effect of improving is obtained. Here, the caking component is not particularly limited as long as it is effective for the formation of the desired granulated body, such as organic substances such as higher alcohol, methylcellulose and polyvinyl alcohol, or sodium silicate and bentonite. Various things such as inorganic substances can be used.

In the embodiment, a countercurrent heat treatment apparatus (not shown) can be used. This is because the discharge port 7, the temperature holding means K, the intermediate cover 48, and the spiral 57 provided in the wall portion of the furnace core tube 10 are eliminated in the parallel flow type heat treatment apparatus S, and the discharge port is connected to the furnace core. The downstream end (exhaust port 10b) of the pipe 10 is configured, and the air supply unit 50 is further connected to the exhaust port outlet 53 (configured as an air supply port) of the downstream end cover unit 52, and air is supplied from the downstream side. It is configured to be sent to the upstream side and discharged from an air supply port 56 (configured as an exhaust outlet) of the upstream end cover portion 51. Further, an outlet for taking out the processed product W discharged from the outlet 10 b of the furnace core tube 10 is provided at the lower part of the downstream end cover 52.
Also by this, it is possible to obtain a desired quicklime-containing fired product with the required setting by the control unit 60.

When this counter-current type heat treatment apparatus is used, there is a possibility that fine particles or fine powder contained in the processed product W may be scattered on the supply side of the processed product W due to the ventilation in the furnace. Accordingly, in such a case, at one or more of the upstream side of the furnace core tube 10, the supply path of the processed material W until the processed material W is introduced to the furnace core tube 10, and the supply equipment of the processed material. Addition of one or more of water and aqueous solutions / suspensions containing caking components is effective in suppressing scattering. Here, as described above, as the caking component, various substances can be used regardless of whether they are organic or inorganic.

The calcined lime-containing fired product thus obtained is firstly 60 to 99% by weight of CaO, 0.1 to 5% by weight of carbonate (CO ₂ equivalent value), 0.01 to 5% of Al ₂ O _3. It contains 20% by weight, 0.01 to 20% by weight of SiO _2, has a hydration activity of 0.5 to 60 seconds, and a BET specific surface area of 3 m ² / g or more. Preferably, it contains 70 to 99% by weight of CaO and 0.1 to 3% by weight of carbonate (CO ₂ equivalent value), has a hydration activity of 0.1 to 30 seconds, and a BET specific surface area of 10 m ² / g. That's it. The carbonate (CO ₂ equivalent value) means the content of CO ₂ contained in the target product, and is mainly derived from unreacted calcium carbonate.

Here, the hydration activity is a measure of the hydration reactivity measured by the following method. As understood from the measurement method, the smaller the value, the higher the hydration activity. The
1) Put 600 g of water at 20 ° C. into a heat insulating container (dewar bottle) equipped with a temperature measuring device, and put 150 g of a sample whose particle size is adjusted to 3.36 mm or less.
2) Continuously measure the digestion exothermic temperature with a temperature measuring device attached to the heat insulating container, and confirm the temperature when the exothermic temperature reaches the maximum.
3) Read the time when the temperature reaches 80% of the maximum exothermic temperature, and let this be the hydration activity.

This calcined lime-containing fired product defines a CO ₂ content of 0.1 to 5% by weight, in other words, a low level of unreacted lime content, and at the same time hydrates. The main feature is that the activity is 0.5 to 60 seconds, and the BET specific surface area is 3 m ² / g or more, which defines a high hydration activity and a specific surface area that are difficult to achieve by the conventional firing method. . Highly active quicklime is generally called soft calcined quicklime, and it is a manufacturing requirement to burn near the decarboxylation temperature in a short time. In order to satisfy this requirement, an internal-heat-type rotary furnace is currently suitable. However, as described above, the activity and the decarboxylation rate are in a trade-off relationship, and as the activity is pursued, the residual CO _{2 is} increased. Usually, the content of unreacted lime increases. It was the calcined lime-containing fired product according to the present invention that overcame such a trade-off relationship, in which low residual CO ₂ , high hydration activity (short-term hydration activity value), and high specific surface area (high activity) were combined. It is possible to achieve both. Both of these values vary depending on the type and properties of the calcareous raw material used and the firing conditions, but it is a by-product lime with a calcium carbonate purity of around 90%, such as fine dust and wet residue generated in limestone mines. Even so, a calcined lime-containing fired product having a CO ₂ content of 0.1 to 3% by weight, a hydration activity of 0.5 to 30 seconds and a BET specific surface area of 5 to 20 m ² / g can be obtained. Further, when a fine calcareous raw material or crystalline limestone from which high activity is easily obtained is used as a raw material, CO ₂ is 0.1 to 3% by weight, hydration activity is within 10 seconds, and BET specific surface area is 20 m ² / A calcined lime-containing fired product exceeding g can also be easily realized.

The rules for chemical components are as follows. First, the content of CaO is preferably as high as possible in order to maximize the function of quicklime, but the lower limit for achieving the function is 60% by weight. It is because the value as a calcareous product will be greatly impaired if less than this. The CO ₂ content is 0.1 to 5% by weight. The upper limit of the CO ₂ content is 5% by weight, which is the minimum condition for securing the product value as quicklime, and in that sense, it is preferably 3% by weight or less. The contents of Al ₂ O ₃ and SiO ₂ are both 0.01 to 20% by weight, and the values are set as appropriate according to the intended use of the product. That is, in applications where high-purity CaO is required, the content of Al ₂ O ₃ and SiO ₂ must inevitably be low. For example, a quicklime-containing fired product according to the present invention is used for steelmaking. When used as a refining agent, the content of Al ₂ O ₃ and SiO ₂ functioning as flux is recommended to be 2 to 20% by weight. The method of adjusting the components of these Al ₂ O ₃ and SiO ₂ is not particularly specified, and if there is a shortage of content based on the chemical components of the calcareous raw material, use the auxiliary raw material as described above. Adjusting is also one way.

The calcined lime-containing fired product thus obtained is secondly CaO 15 to 60% by weight, carbonate (CO ₂ equivalent value) 0.1 to 5% by weight, Al ₂ O ₃ 10 to 10%. 50% by weight, 15 to 50% by weight of SiO ₂ and a BET specific surface area of 1 m ² / g or more.
As seen from the above chemical components, the calcined product containing quick lime has a lower CaO content than the first calcined product containing quick lime. This is derived from the content of the lime component in the treated product, and is characterized by being a calcined lime-containing fired product having a high specific surface area even when the content is lowered. This calcined lime-containing fired product has a relatively reduced CaO content as compared with the first calcined lime-containing calcined product, whereas the content of Al ₂ O ₃ and SiO ₂ is increased. Therefore, in addition to quick lime of activity, in a steel refining to increase requiring Al ₂ O ₃ and SiO ₂ as a flux, the quick lime-containing baked product is particularly useful.
In addition, the calcareous raw material / sub-raw material, the baking apparatus / method, and the like used in the production of the quicklime-containing fired product are the same as described above.

Further, the quicklime-containing fired product according to another embodiment of the present invention is obtained by hermetically packaging the obtained quicklime-containing fired product with a moisture-proof material. Since it is hermetically packaged, it is effective for suppressing deterioration. Although the moisture-proof material is not particularly limited, an aluminum foil film, an aluminum vapor-deposited film, an inorganic vapor-deposited film obtained by vapor-depositing silicon or aluminum oxide on a resin film, and the like are preferable because they have excellent moisture permeability. The calcined lime-containing fired product packaged with a moisture-proof material may be used after being unpacked and opened, or may be used in a packaged state. In particular, the components constituting the packaging material with high moisture resistance, that is, aluminum and silicon / aluminum oxide, have a refining effect. It is preferable to use it in molten steel. The same applies to the injection method, and a method is also recommended in which a package is produced in accordance with the injection equipment, and the package itself is injected into the molten steel by injection.

In addition, when the quicklime-containing fired product of the present invention is used as a refining agent for steelmaking, it is not impeded to add other refining agents to the quicklime-containing fired product, but rather positive in enhancing the refining effect. It can be said that this should be adopted. Here, other refining agents are those generally used, such as steel slag, coal ash, fluorite, nepheline, calcium aluminate, calcium silicate, calcium aluminosilicate, aluminum ash, soda ash, Examples include serpentine, dolomite, metallic calcium, metallic magnesium, and calcium carbide. The use form of these refining agents is not particularly limited, but it is fine, previously mixed with the calcined lime-containing fired product of the present invention, or after mixing, a briquette machine, a uniaxial compression molding machine, etc. It is preferable to use it as a molded body because it is effective in improving the refining effect.

The present invention also includes calcination of lime mud in the production of kraft pulp. Details will be described below. In the manufacture of kraft pulp, in preparing sodium hydroxide used in the causticizing process, the process of digesting quick lime to make slaked lime, reacting slaked lime with sodium carbonate, sodium hydroxide for use in the causticizing process A calcareous raw material circulation system has been constructed which comprises a step of recovering lime and a step of calcining lime mud mainly composed of calcium carbonate, which is a by-product of the reaction, to obtain quick lime. Since this lime mud has a high water content and contains fine and fine calcium carbonate, it is difficult to handle due to the high adhesion of lime mud when firing this, low thermal efficiency, treatment during firing There are various problems such that the product adheres to the firing furnace, the processed product attached to the firing furnace falls, and the fallen product forms a lump, resulting in uneven burning of the fired product.
As described above, in the present invention, a high-quality calcined lime-containing fired product having a fine and high water content, high activity even from a treated product having high scattering properties and adhesion, and a high specific surface area can be obtained. The lime mud having the above properties can be obtained stably and efficiently without any exception from the lime mud having the above properties. However, when the object to be treated is limited to lime mud in the causticizing step, the advantages of the present invention are not limited to the above.

First, since the content of carbonate in the fired product, specifically calcium carbonate, is low, in the subsequent steps, the residual amount of unreacted lime (calcium carbonate) is reduced, and as a result This means that the additional amount of calcareous material that becomes insufficient in the circulation process can be reduced. That is, the lime circulation process in the causticizing process is as follows: (1) Process of digesting quick lime to make slaked lime: CaO + H ₂ O → Ca (OH) ₂ , (2) Reaction of slaked lime with sodium carbonate, Step of recovering sodium hydroxide for use: Ca (OH) ₂ + Na ₂ CO ₃ → 2NaOH + CaCO ₃ , (3) calcining lime mud mainly composed of calcium carbonate, which is a by-product of the above reaction, and quick lime to _{_{step: CaCO 3 → CaO + CO 2}} , composed. Here, in the calcination of lime mud (3), if the decomposition reaction of lime (calcium carbonate) is not sufficiently performed and unreacted lime remains in the fired product, ) And (3), it remains as it is as an inactive substance that does not affect the reaction. In other words, if unreacted lime remains in the step (3) and the process proceeds to the next step without taking this residue into consideration, the stoichiometry in the steps (2) and (3) is maintained. It will not drool, that is, it will fall into the situation where the required amount of caustic soda (NaOH) used for cooking of kraft pulp cannot be obtained. In order to avoid this, in the lime circulation process, a new calcareous raw material is generally supplied to compensate for the lack of calcareous material. In addition, this additional supply is intended not only to compensate for the shortage of calcareous due to unreacted lime, but also to replenish calcareous that leaks out of the system in the handling process.

In order to solve the above problem, in the step (3), a measure of increasing the degree of firing, that is, calcining the lime mud at a higher temperature for a longer time can be considered. The quick lime obtained in (1) has a low activity, which causes the problem of slowing down the reaction rate in the step (1).
In this way, calcining of lime mud in the causticizing process requires a balance between the degree of calcining and the activity that can be said to be in a trade-off relationship. The characteristics of the present invention can be greatly exhibited. In addition, reducing the additional supply of calcareous raw materials in the lime circulation process is important not only in reducing the basic unit of calcareous raw materials in the papermaking process and reducing production costs, but also in preserving natural resources. It has meaning.

In the calcination of lime mud in the causticizing step, the second advantage of the present invention is that the quick lime-containing fired product obtained in the step (3) has high activity, so that the digestion reaction in the step (1) proceeds quickly. That is, the reaction efficiency of (1) is improved.
Moreover, in the calcination of the lime mud in the causticizing step, the third advantage of the present invention is that the slaked lime obtained in the step (1) has a specific surface area as compared with the slaked lime obtained by the conventional technique as described later. And the activity is high, the reaction in the step (2) is promoted.
Furthermore, in the calcining of lime mud in the causticizing step, the fourth advantage of the present invention is that the heat of digestion generated in the step (1) further promotes the reaction in the step (2). . In general, in the reaction (2), in order to increase the efficiency, the reaction temperature is preferably as high as possible without boiling. Since the reaction (1) is an exothermic reaction, digestion heat is generated depending on the magnitude of the reaction, and the heat of digestion is inevitably used for the reaction promotion of (2). The calcined lime-containing fired product obtained in the present invention has a high activity. Therefore, in the reaction (1), a higher-temperature digestion heat is generated, so that the effect can be further enhanced.

Furthermore, this invention exists in the slaked lime containing digested material obtained by digesting said calcined lime containing baked material. As described above, the calcined lime-containing fired product obtained in the present invention has a very high specific surface area. Therefore, a digested product obtained by digesting it, that is, a slaked lime-containing digested product, inevitably exhibits a high specific surface area. In general, slaked lime used for exhaust gas treatment is not simply digested with quick water, but with high specific surface area and high reactivity. Slaked lime. On the other hand, the calcined lime-containing fired product of the present invention has such a high reactivity that it functions as an exhaust gas treating agent by itself, and therefore, when digesting this, without using any additive In addition, slaked lime having a high specific surface area and high reactivity can be obtained only with water. Specifically, depending on the properties of the calcined product containing quicklime as a starting material, CaO is 60 to 99% by weight, carbonate (CO ₂ equivalent value) is 0.1 to 5% by weight, and hydration activity is 0. When a calcined lime-containing fired product having a BET specific surface area of 3 m ² / g or more for 5 to 60 seconds is used as a starting material, slaked lime having a high specific surface area of 20 to 50 m ² / g can be easily obtained. Also, CaO is 15 to 60% by weight, Al ₂ O ₃ is 10 to 50% by weight, SiO ₂ is 15 to 50% by weight, carbonate (CO ₂ equivalent value) is 0.1 to 5% by weight, BET specific surface area Even when the quick lime-containing fired product having a weight of 1 m ² / g or more is used as a starting material, slaked lime of several m ² / g or more can be easily obtained.

Examples of the present invention will be described below together with comparative examples.
As the processed material, calcareous raw materials (A to K) shown in FIG. 4 were prepared.
In connection with Examples 1 to 18, as a heat treatment apparatus (denoted as “rotary retort furnace” in the chart), a “parallel flow” type experimental furnace similar to the heat treatment apparatus described above, and a “countercurrent” similar to the above. A type experimental furnace (with a discharge port formed at the downstream end of the furnace core tube) was created (see Patent Nos. 2944996 and 3073717 of the present applicant for the heat treatment apparatus). Each experimental furnace is of the electric heater type built in a furnace core tube having an inner diameter of 200 mm, an overall length of 4,000 mm, and an effective length (the length of the heating part) of 2,500 mm.
Further, according to Comparative Examples 1, 3, 4, 6, 8, 11 to 15, an internal heating type rotary furnace having an inner diameter of 200 mm and a total length of 2,500 mm was prepared. Further, a rotary furnace (hereinafter referred to as “external heating type rotary furnace”) in which the beater member was removed from the above counter-current type heat treatment apparatus was prepared according to Comparative Examples 2, 5, and 7.
Also, in connection with Comparative Examples 9 and 10, in the above-mentioned “countercurrent” type experimental furnace (the discharge port is configured at the downstream end of the furnace core tube), a parallel flow type experimental furnace in which the air flow is simply reversed is also prepared. did.
In addition, as calcining furnaces for calcareous materials, there are standing furnaces such as Beckenbach furnace, Melz furnace, Koma type furnace, etc., but in order to ensure ventilation in the furnace, the size used in the present invention is 5 mm or less. The calcareous raw material cannot be fired. Therefore, in the comparative example, these standing furnaces were excluded, and the above-mentioned internal heat type rotary furnace and external heat type rotary furnace were used as firing furnaces.

A. Examples 1 to 7 and Comparative Examples 1 to 8
In Examples 1 to 7, the calcareous material shown in FIG. 4 was fired by the heat treatment apparatus described above.
Further, as Comparative Examples 1 to 8, the calcareous raw material shown in FIG. 4 was fired in the same manner as in the example using the internal heating type rotary furnace and the external heating type rotary furnace.
Firing conditions (feeding amount of raw materials, firing temperature, firing time), status of adhesion of fired product in furnace, recovery rate of fired product, properties of fired product (CaO content, Al ₂ O ₃ content, SiO ₂ content Amount, CO ₂ content, hydration activity, BET specific surface area) are shown in FIGS.

5 and 6, * 1 to * 5 mean the following.
* 1: Symbol in Fig. 4 * 2: The recovered material from the bag filter connected to the raw material input part of the firing furnace and the outlet part of the fired product is added to the fired raw material again. * 3: The fired product recovered as a product from the firing furnace. 2 kg per hour, and the recovered material from the bag filter connected to the raw material input part and the fired product outlet part of the baking furnace are added to the baking raw material again. * 4, 5: Bag filter connected to the raw material input part of the baking furnace and the fired product outlet part The recovered material was added again to the calcining raw material, and these calcining raw materials were mixed by spraying a carboxymethyl cellulose aqueous solution with a screw-type mixer before being put into the calcining furnace, and this mixture was quantitatively supplied to the calcining furnace.

In Example 1, Comparative Example 1, and Comparative Example 2, amorphous limestone having a size of 5 mm or less was used as a firing raw material. As can be seen from FIGS. 5 and 6, in Example 1 using the heat treatment apparatus, almost no adhesion of the material to be fired to the inner wall of the furnace core tube was observed, and the stable low CO ₂ content. In addition, a calcined lime-containing fired product having a high hydration activity (short-term hydration activity value) and a high specific surface area could be obtained with a high recovery rate. On the other hand, in the internal heating type rotary furnace (Comparative Example 1), adherence of the material to be fired to the inner wall of the kiln was observed, and stable firing was inhibited. Moreover, the burning raw material of fine particles / fine powder of 3 mm or less was blown off by the combustion air to the raw material charging port (kiln bottom), and the product recovery rate was low. Furthermore, the obtained calcined lime-containing fired product had a high CO ₂ content, a low hydration activity, and a low specific surface area due to a short pass of the material to be fired. In the externally heated rotary furnace (Comparative Example 2), relatively good values of the CO ₂ content, hydration activity, and specific surface area of the fired product can be obtained. The adhesion of the fired product was increased, and stable firing was inhibited. As a result, compared with Example 1, the product recovery rate was reduced, and the increase in adhesion in the furnace forced the material feed amount to be significantly suppressed.

In Example 2, the same raw material was used, and the amount of feed was further increased compared to Example 1, and the residence time was shortened for firing. As a result, compared with Example 1, although the CO ₂ content was reduced and the BET specific surface area was also reduced, it was compared with the internal heating type rotary furnace (Comparative Example 1) and the external heating type rotary furnace (Comparative Example 2). For example, it was a much higher quality calcined calcined product. Moreover, the stability at the time of baking was not different from Example 1, and showed a high product recovery rate.

In Example 3, crystalline limestone having a size of 5 mm or less was used as the calcareous material. Although atomization due to self-disintegration occurred in the firing process, adhesion of the object to be fired in the furnace was not observed, but rather easy atomization improved by atomization, resulting in a high specific surface area compared to Example 1. A burned product containing quicklime was obtained. On the other hand, in Comparative Example 3 using the same raw material, due to the atomization of the raw material in the firing process, the adherence of the material to be fired and scattering outside the furnace increased, and the recovery rate of the fired material was a comparative example. Further lower than 1.

In Example 4, fine slaked lime was used as the calcareous material. Almost no adhesion within the furnace was observed, but the dispersion of the fired product outside the furnace increased due to the ventilation in the furnace, and the recovery rate of the fired product was slightly reduced as compared with Examples 1 to 3. However, the specific surface area of the obtained calcined lime-containing fired product was extremely high. On the other hand, when the same raw material is baked in an internal heating type rotary furnace (Comparative Example 4), most of the baked material is scattered outside the furnace due to the influence of combustion gas, and the recovery rate of the baked material is extremely small. there were. Further, in the external heating type rotary furnace (Comparative Example 5), the adherence of the object to be fired in the furnace started immediately after firing, and the furnace was closed in a short time, and it was determined that firing was impossible.

In Example 5, recovered dust generated from a limestone mine was calcined as a calcareous material. As clearly shown in FIGS. 5 and 6, there is no adhesion in the furnace, and a calcined lime-containing fired product having a low CO ₂ content, a high hydration activity, and a high specific surface area can be stably obtained at a high recovery rate. It was. On the other hand, in Comparative Example 6 in which the same raw material was fired in an internal heating type rotary furnace, the recovery rate of the fired product was extremely low due to scattering of the fired product by the combustion gas outside the furnace.

In Example 6, the byproduct lime generated from the sugar making process was used as the calcareous material. Combustible organic substances are attached to the by-products of the sugar production process, so these combustions were confirmed in the firing process, but there was almost no adhesion of the products to be fired to the inner wall of the furnace core tube, and a low CO ₂ content, high A calcined calcined product having a hydration activity and a high specific surface area was obtained. Further, the combustion of the combustible organic material in the furnace reduced the load on the electric heater, and the calorific value was reduced by half compared to the previous examples. On the other hand, when the same raw material was fired in an externally heated rotary furnace (Comparative Example 7), the inside of the furnace was closed due to the adherence of the material to be fired, and it was determined that firing was impossible. This adhesion was more remarkable than that of Comparative Example 5, which was considered to be due to the combustion of combustible organic matter.

In Example 7 and Comparative Example 8 (internally heated rotary furnace), as a calcareous raw material, a mixture of amorphous limestone used in Examples 1 and 2 and byproduct lime of sedimentation residue generated during slaked lime production is used. Using. The results follow the previous examples and comparative examples.

B. Examples 8 and 9 and Comparative Examples 9 and 10
In Example 8 and Comparative Example 9, amorphous limestone having a size of 5 mm or less was calcined as a calcareous material by a heat treatment apparatus in a parallel flow method. As is clear from FIGS. 5 and 6, in both Example 8 and Comparative Example 9, no adherence of the fired product to the inner wall of the furnace core tube during firing was confirmed, and the fired product was obtained by co-current firing. The recovery rate was high. However, a large difference was confirmed in the properties of the fired product. That is, in Example 8 where the outlet temperature of the fired product was set to 820 ° C., a calcined lime-containing fired product having a low CO ₂ content, a high hydration activity, and a high specific surface area was obtained, but the outlet temperature was set to 600 ° C. In Comparative Example 9, the calcined lime-containing fired product obtained by the carbon dioxide reabsorption reaction, which was considered to have occurred during the cooling process of the material to be fired in the furnace core tube, had a high CO ₂ content and low hydration activity. The specific surface area was low.

In Example 9 and Comparative Example 10, the recovered dust generated from the limestone mine was used as the calcareous raw material, and this was fired in a parallel flow system using a heat treatment apparatus. As a result, in both Example 9 and Comparative Example 10, the adherence of the material to be fired to the inner wall of the furnace core tube during firing was not confirmed, and the recovery rate of the fired material was high due to co-current firing. However, the properties of the fired product showed the same tendency as in Example 8 and Comparative Example 9, and in Example 9 where the exit temperature of the fired product was set to 900 ° C., the content of quick lime with a low CO ₂ content and a high specific surface area was included. Although a fired product was obtained, Comparative Example 10 in which the outlet temperature was set to 500 ° C. had a high CO ₂ content, a low hydration activity, and a low specific surface area.

C. Example 10 and Comparative Example 11
In Example 10 and Comparative Example 11, byproduct lime (limestone mine dewatered cake) having a size of 5 mm or less was calcined as a calcareous material by a countercurrent system. In spite of containing Al ₂ O ₃ and SiO ₂ in addition to calcareous material, calcined lime-containing fired product having a relatively high hydration activity and BET specific surface area can be obtained at a high recovery rate of 89% in Example 10. It was. Furthermore, stable firing could be performed without forming deposits in the furnace during the firing process. On the other hand, in Comparative Example 11 using the internal heating type rotary furnace, most of the raw material was scattered on the raw material charging side, and as a result, the recovery rate of the fired product was as low as 8%. Also, during the firing process, fine powder material adhered to the inner wall of the rotary furnace, impeding stable firing. Furthermore, the hydration activity and BET specific surface area of the fired product were also low.

D. Example 11 and Comparative Example 12
In Example 11 and Comparative Example 12, papermaking sludge having a size of 30 mm or less and a moisture content of 40% was baked by a countercurrent method as a processed product. The calcined product obtained in Example 11 had a CaO content of 33% by weight, which was lower than that of the above example, but the calcined lime-containing calcined product having a BET specific surface area of 1 m ² / g or more was obtained. A relatively high recovery rate of 87% could be obtained. Furthermore, stable firing could be performed without forming deposits in the furnace during the firing process. On the other hand, in Comparative Example 12 using the internal heating type rotary furnace, the firing started to adhere to the inner wall of the rotary furnace at the same time as the firing was started, and the furnace was closed within a short time. This adhesion was even more remarkable than that confirmed in the above comparative example, and this was presumed to be due to the moisture contained in the treated product, the pulp quality, and the combustion of the organic matter containing the pulp quality.

E. Example 12 and Comparative Example 13
In Example 12 and Comparative Example 13, a papermaking sludge having a size of 10 mm or less and a water content of 50% was baked in a countercurrent manner as a treated product. The calcined product obtained in Example 12 had a CaO content of 15% by weight, which was even lower than that of Example 11, but had a quick lime-containing calcined product having a BET specific surface area of 1 m ² / g or more. Could be obtained with a relatively high recovery rate of 88%. Furthermore, stable firing could be performed without forming deposits in the furnace during the firing process. On the other hand, in Comparative Example 13 using the internal heating type rotary furnace, as in Comparative Example 12, the material to be fired started to adhere to the inner wall of the rotary furnace at the same time as firing was started, and the inside of the furnace was closed within a short time. Ceased firing. This adhesion was even more remarkable than that confirmed in the above comparative example, and this was presumed to be due to the moisture contained in the treated product, the pulp quality, and the combustion of the organic matter containing the pulp quality.

F. Example 13 and Comparative Example 14
In Example 13 and Comparative Example 14, 60% by weight of papermaking sludge having a size of 30 mm or less and a water content of 40%, which was used in Example 11 and Comparative Example 12, was used as the treated product. A mixture of 40% by weight of amorphous limestone having a thickness of 5 mm or less was fired in a countercurrent manner. Since the high-content amorphous limestone was mixed with the papermaking sludge having a low calcareous content, the calcareous content of the treated product was relatively increased. As a result, the CaO content of the fired product obtained in Example 13 was increased. Was 57 wt%, which was higher than that in Example 11. As a result, the BET specific surface area of the fired product was higher than that of Example 11. Moreover, the recovery rate of the fired product was as high as 90%. Furthermore, stable firing could be performed without forming deposits in the furnace during the firing process. On the other hand, in Comparative Example 14 using the internal heating type rotary furnace, as in Comparative Example 12 and Comparative Example 13, an object to be fired adhered to the inner wall of the rotary furnace, which hindered stable operation. It was barely possible to fire. The reason why the adhesion was reduced as compared with Comparative Example 12 was presumed to be because the content of papermaking sludge was relatively reduced by the addition of amorphous limestone. Compared with Example 13, the component content of the fired product was high CaO, low Al ₂ O ₃ , and low SiO ₂ . This was thought to be a result of the paper sewage sludge being selectively adhered to the furnace during the firing process and the content of amorphous limestone in the treated product increased. Although the CaO content in the fired product was higher than that in Example 13, the BET specific surface area was as low as 1 m ² / g or less. Moreover, the recovery rate of the fired product was low due to the adhesion of the treated product in the furnace.

G. Example 14 and Comparative Example 15
In Example 14 and Comparative Example 15, as a processed material, the size used in Example 12 and Comparative Example 13 was 60% by weight of papermaking sludge having a size of 10 mm or less and a moisture content of 50%, and the size used in Example 3. A mixture of 40% by weight of crystalline limestone having a length of 5 mm or less was fired in a countercurrent manner. Since crystalline limestone having a high content is mixed with papermaking sludge having a low calcareous content, the calcareous content of the treated product is relatively increased, and as a result, the CaO content of the fired product obtained in Example 14 is 47% by weight, which was higher than that in Example 12. In addition, combined with the characteristics of crystalline limestone that causes self-disintegration during the firing process, the BET specific surface area of the fired product was a high value that greatly exceeded Example 12. Furthermore, the recovery rate of the fired product was as high as 90%. As in the previous examples, stable firing could be performed without forming deposits in the furnace during the firing process. On the other hand, in Comparative Example 15 using the internal heating type rotary furnace, adhesion in the furnace was made to the same extent as in Comparative Example 14 and the stable operation was hindered, but the furnace was not blocked and could be barely fired. . The reason why the adhesion was reduced as compared with Comparative Example 13 was presumed to be because the content of papermaking sludge was relatively reduced by the addition of crystalline limestone. Compared with Example 13, the component content of the fired product was high CaO, low Al ₂ O ₃ , and low SiO ₂ . Similar to Comparative Example 14, it was considered that only the papermaking sludge selectively adhered to the furnace during the firing process and the content of crystalline limestone in the treated product increased. Although the CaO content in the fired product was higher than that in Example 14, the BET specific surface area was as low as 1 m ² / g or less. Moreover, the recovery rate of the fired product was low due to the adhesion of the treated product in the furnace.

H. Example 15
In Example 15, the same by-product lime (amorphous limestone mine recovery dust) used in Example 5 was calcined in a countercurrent manner under calcining conditions similar to those in Example 5. The only difference from Example 5 is that the recovered material from the bag filter connected to the raw material charging portion and the fired material outlet portion of the baking furnace was fired while being constantly added to the calcareous raw material. By returning the fine dust scattered outside the furnace during the firing process to the firing raw material, the recovery rate of the fired product was improved from 85% (Example 5) to 89% (Example 15). In addition, even if the recovered material from the bag filter is added to the calcareous material, the property of the fired product does not change, and in the same way as in Example 5, no deposits are formed in the furnace, and stable. Was able to be performed.

I. Example 16
In Example 16, the same papermaking sludge as that used in Example 11 was fired in the countercurrent system using the same firing conditions as in Example 11 on the firing raw material. The difference from Example 11 on firing is that the recovered material from the bag filter connected to the raw material charging portion and the fired product outlet portion of the firing furnace and the fired product recovered as a product from the firing furnace are subjected to the above firing. It is the point which baked, always adding to a raw material. The amount of fired product was 2 kg per hour. By returning the fine dust scattered outside the furnace during the firing process to the firing raw material, the recovery rate of the fired product was improved from 87% (Example 11) to 91% (Example 16). In addition, the amount of raw material transfer slightly observed in the baking raw material supply section is obtained by quantitatively adding the recovered material from the bag filter and the fired material recovered as a product from the baking furnace to the papermaking sludge having a high water content. Improved. This is because the moisture content in the calcined raw material is reduced by adding the recovered material and the calcined product in a dry state to the papermaking sludge. In addition, even if it adds said collection | recovery material and a baked material to a baking raw material, a change does not arise in the property of a baked material, and also in Example 11, it does not form a deposit in a furnace in a baking process. Stable firing was possible.

J. et al. Example 17
In Example 17, the same byproduct lime (amorphous sugar production process product) firing raw material used in Example 6 was fired in a countercurrent manner under the same firing conditions as in Example 6. On firing, the difference from Example 6 is that the recovered material from the bag filter connected to the raw material charging portion and the fired product outlet of the firing furnace is added again to the firing raw material, and these firing raw materials are added to the firing furnace. Before being charged, the mixture was mixed by spraying a carboxymethyl cellulose aqueous solution with a screw-type mixer, and this mixture was quantitatively supplied to a baking furnace. The bag filter recovered material scattered outside the furnace during the firing process is returned to the firing raw material, and the firing raw material is mixed with an aqueous solution containing a caking component to coarsen (granulate) fine particles. The recovery rate of the product was greatly improved from 80% (Example 6) to 93% (Example 17). In addition, even if it adds said collection | recovery thing and a baked material to a baking raw material, a change does not arise in the property of a baked material, and also in Example 6, it does not form a deposit in a furnace. Stable firing was possible.

K. Example 18
In Example 18, the same by-product lime (amorphous limestone mine recovery dust) used in Example 9 was fired in a co-current manner under the same firing conditions as in Example 6 using the firing raw material. On firing, the difference from Example 9 is that the recovered material from the bag filter connected to the raw material input part of the firing furnace and the fired product outlet part is added again to the fired raw material, and these firing raw materials are added to the firing furnace. Before being charged, the mixture was mixed by spraying a carboxymethyl cellulose aqueous solution with a screw-type mixer, and this mixture was quantitatively supplied to a baking furnace. The bag filter recovered material scattered outside the furnace during the firing process is returned to the firing raw material, and the firing raw material is mixed with an aqueous solution containing a caking component to coarsen (granulate) fine particles. The product recovery rate improved from 94% (Example 9) to 98% (Example 18). In addition, even if it adds said collection | recovery thing and a baked product to a baking raw material, a change does not arise in the property of a baked product, and also in Example 9 does not form a deposit in a furnace in the baking process. Stable firing was possible.

L. Examples 19 to 20 and Comparative Examples 16 to 17
In order to evaluate the effect of the packaging on the obtained calcined lime-containing fired product, a moisture absorption test of the specimen under constant temperature and humidity was performed. The test conditions are as follows.
Test raw material: calcined lime-containing fired product obtained in Example 1 (100 g)
Preparation of test specimen: Test environment in which the above-mentioned test raw materials are hermetically sealed by heat sealing using the packaging material shown in FIG. 7: 30 ° C., 90% RH
Test period: 30 days Measurement item: Weight change rate before and after the test

The test results are shown in FIG. As is clear from FIG. 7, the specimen wrapped with the aluminum foil film, which is a moisture-proof material, and the aluminum vapor-deposited film showed almost no change in weight even after 30 days of testing. On the other hand, in Comparative Example 16 where no packaging was applied, an increase of 47% was confirmed. This is a result of the quick lime being transformed into calcium hydroxide and calcium carbonate by moisture and carbon dioxide present in the test environment. Further, in Comparative Example 17 packaged with a polyethylene film which is considered to have poor moisture resistance, a large increase was recognized due to absorption of moisture and carbon dioxide.

M.M. Examples 21 to 24 and Comparative Examples 18 to 19
Subsequently, the calcined lime-containing fired product of the present invention was digested to examine the properties of the slaked lime-containing digested product. The slaked lime was digested while adding the same amount of water to the calcined lime-containing fired product in a stirred state with a high-speed shear mixer, and seemingly kept dry. The digested product was dried at 180 ° C., and this dried product was crushed on a 0.5 mm sieve, and the recovered sieve was used as a test material.

As shown in FIG. 8, a calcined calcined product obtained by calcining amorphous limestone with a heat treatment device (Example 1) and a dehydrated cake generated from the limestone mining / processing step are calcined with a heat treatment device. Although the digested product (Examples 21 and 22) of the obtained calcined lime-containing fired product (Example 10) was digested only with water, alcohols and glycols at the time of digestion were 32 m ² / g and 48 m ² / g. It was a digested product having a high specific surface area equivalent to the high specific surface area slaked lime produced by adding a kind. This is nothing but the high specific surface area of the quicklime containing digest. On the other hand, in Comparative Example 18 and Comparative Example 19 in which the above calcareous raw material was baked in an internal-heated rotary furnace and digested, the ratio as high as that of the example was caused by the specific surface area of the base quicklime-containing digested product. The surface area could not be obtained.
In addition, the digested product (Examples 23 and 24) of the calcined lime-containing calcined product (Examples 11 and 12) obtained by calcining paper sludge with a heat treatment apparatus is also digested only with water and contains quicklime. Although the amount was significantly reduced as compared with Examples 1 and 10 above, digests having a high specific surface area of 22 m ² / g and 15 m ² / g were obtained.

As described above, by using the present invention composed of a firing furnace, a firing method, firing conditions, and the like, various fine and fine calcareous raw materials that have been difficult to fire so far can be stably and economically used. Can be fired. The fired product has high hydration activity and specific surface area, and can be effectively used in various fields. Furthermore, the digested product of the fired product also has a high specific surface area, and can be effectively used in various fields.

The calcined lime product of the present invention can be effectively used in the fields of steel, chemistry, papermaking, architecture, civil engineering, and agriculture. The slaked lime-containing digested product of the present invention can be effectively used in fields such as architecture, civil engineering, agriculture, water purification, and exhaust gas purification.

Claims

In the calcined lime-containing fired product obtained by firing a processed product having a lime component size of 5 mm or less,
As said processed material, it comprises any one or more calcareous raw materials among limestone, slaked lime and byproduct lime, and auxiliary raw materials blended as necessary,
A furnace core tube for heating the processed material, and a plurality of rows are provided along the direction of the central axis of the furnace core tube provided in the furnace core tube, and the inner periphery of the furnace core tube is rotated by the rotation of the furnace core tube. The processed product is fired in the range of 400 ° C. to 1200 ° C. by a heat treatment apparatus including a beater member that rolls the surface and imparts an impact to the processed product.
It contains 60 to 99% by weight of CaO and 0.1 to 5% by weight of carbonate (CO 2 equivalent value), has a hydration activity of 0.5 to 60 seconds, and a BET specific surface area of 3 m 2 / g or more. A calcined lime-containing fired product.
2. The calcined lime-containing fired product according to claim 1, comprising 0.01 to 20% by weight of Al 2 O 3 and 0.01 to 20% by weight of SiO 2 .
In the calcined lime-containing fired product obtained by firing a processed product having a lime component size of 5 mm or less,
As said processed material, it comprises any one or more calcareous raw materials among limestone, slaked lime and byproduct lime, and auxiliary raw materials blended as necessary,
A furnace core tube for heating the processed material, and a plurality of rows are provided along the direction of the central axis of the furnace core tube provided in the furnace core tube, and the inner periphery of the furnace core tube is rotated by the rotation of the furnace core tube. The processed product is fired in the range of 400 ° C. to 1200 ° C. by a heat treatment apparatus including a beater member that rolls the surface and imparts an impact to the processed product.
Containing 15 to 60% by weight of CaO, 10 to 50% by weight of Al 2 O 3 , 15 to 50% by weight of SiO 2 and 0.1 to 5% by weight of carbonate (CO 2 equivalent value), and BET ratio A calcined lime-containing fired product having a surface area of 1 m 2 / g or more.
The calcined lime-containing fired product according to any one of claims 1 to 3, wherein when limestone is used as the calcareous material, crystalline limestone is used.
When using by-product lime as the calcareous raw material, it is characterized by using any one or more of calcareous by-products generated during the production of limestone, calcium carbonate, quick lime and slaked lime, and calcareous by-products generated from the lime utilization process. The calcined lime-containing fired product according to any one of claims 1 to 4.
6. The processed product contains a calcined lime-containing fired product recovered as a product from the heat treatment apparatus and / or a recovered product other than the product discharged from the heat treatment apparatus. A burned product containing quicklime according to crab.
Before the processed material is supplied to the heat treatment apparatus, a premixed mixture is formed, and the mixture further contains water and a caking component as necessary. The calcined lime-containing fired product according to any one of claims 1 to 6, wherein an aqueous solution and / or a suspension is added and mixed.
The calcined lime-containing fired product according to any one of claims 1 to 7, wherein the calcined product is sealed with a moisture-proof material.
A slaked lime-containing digested product obtained by digesting the calcined lime-containing fired product according to any one of claims 1 to 8.
In the manufacturing method of the quicklime containing baking products which manufacture the quicklime containing baking products in any one of the said Claims 1 thru | or 8,
As the above heat treatment apparatus, the processed material is received on the upstream side and rotated about a central axis extending in a substantially horizontal direction, the processed material is moved from the upstream side to the downstream side, and the processed material is discharged from a discharge port provided on the downstream side. A plurality of rows of furnace core tubes arranged along the direction of the central axis of the furnace core tube and rolling the inner peripheral surface of the furnace core tube by the rotation of the furnace core tube Using a beater member that gives an impact to the processed material, and a furnace core tube heating unit that heats a predetermined section upstream from the discharge port of the furnace core tube from the outside,
Air flowing from the upstream side to the downstream side is flowed into the furnace core tube, and the firing temperature range of the processed material by heating in the furnace core tube heating section is set to 800 ° C. to 1200 ° C., and the furnace core tube heating section A method for producing a calcined lime-containing calcined product, characterized in that the heated treated product is maintained at 800 ° C. to 1200 ° C. within the calcining temperature range until reaching the discharge port.
The upstream side of the furnace core tube, the supply path of the processed product until the processed product is introduced to the furnace core tube, and at any one or more of the supply facilities of the processed product, water, a caking component The method for producing a calcined lime-containing fired product according to claim 10, wherein at least one of an aqueous solution and a suspension containing the lime is added.
In the manufacturing method of the quicklime containing baking products which manufacture the quicklime containing baking products in any one of the said Claims 1 thru | or 8,
As the above heat treatment apparatus, the processed material is received on the upstream side and rotated about a central axis extending in a substantially horizontal direction, the processed material is moved from the upstream side to the downstream side, and the processed material is discharged from a discharge port provided on the downstream side. A plurality of rows of furnace core tubes arranged along the direction of the central axis of the furnace core tube and rolling the inner peripheral surface of the furnace core tube by the rotation of the furnace core tube Using a beater member that gives an impact to the processed material, and a furnace core tube heating unit that heats a predetermined section upstream from the discharge port of the furnace core tube from the outside,
Air flowing from the downstream side to the upstream side in the furnace core tube, and the upstream side of the furnace core tube, the supply path of the processed material until the processed material is introduced to the furnace core tube, A method for producing a calcined lime-containing fired product, comprising adding at least one of water and an aqueous solution / suspension containing a caking component at any one or more locations in a supply facility.