CN101755064A - Ore-powder caking material for enhancing hot strength, pellet made with the same, and process for producing the same - Google Patents

Abstract

The present invention provides a thermal strength-increased solidified material of ore powder for granulation, which is equal to or higher in cold strength than conventional ore powder solidified materials and more excellent in thermal strength, pellets using the same, and a production method thereof. The thermal strength enhancement solidified material of ore powder of the present invention is obtained by mixing any one or two of cement or lime, slag and siliceous substances. In the total of CaO, Al ₂ O ₃ and SiO ₂ , the chemical The composition is: 3-56% of CaO, 3-40% of _Al2O3 , and 30-86% of _SiO2 ; further, in _the solidified material, any one or two of cement or lime, slag and silicon The mixing ratio of acidic substances is: 1-76 parts of any one or both of cement or lime, 2-95 parts of slag, and 2-95 parts of siliceous substances; furthermore, the solidified material also contains gypsum. A kind of granular material, containing ore powder, the solidified material and water; further, in the granular material, relative to 100 parts of ore powder, the solidified material is 3 to 20 parts, water/(ore powder + the solidified material) The ratio is 0.03 to 0.3; and the method for producing the pellets.

Description

Heat-strength-increased solidified material of ore powder, pellets using the same, and manufacturing method thereof

technical field

The present invention relates to a thermal strength enhancing solidification material of ore powder used in granulation of ore powder produced in ironworks, steelworks, non-ferrous metal refineries, etc., a pellet using the material, and a manufacturing method thereof.

Background technique

In the past, granulation was performed on iron ore powder under the background of exhaustion of iron ore powder and high-quality mineral resources that effectively utilize dust generated in factories such as ironworks, steelworks, and non-ferrous metal refineries.

As is well known, as a granulation method of ore powder, there is a firing granulation method in which the granulation is carried out using a drum type (drum) or a pan type (pan) granulation machine, followed by firing, and the firing process is omitted for the purpose of saving energy. cold granulation method.

As the solidified material of the ore powder used in the granulation method of these ore powders, a solidified material formed of ordinary Portland cement, a solidified material formed of quicklime and blast furnace slag, a calcium aluminate-based compound and A cured material made of fine powder inorganic material, and a cured material made of ordinary Portland cement and calcium aluminate (see Non-Patent Document 1, Non-Patent Document 2, Patent Document 1, and Patent Document 2).

However, when these solidified materials are used, there are problems in that the thermal strength is lower than that of sintered ore, and the air permeability is poor due to pulverization after being put into the blast furnace, so the amount of input is limited.

The thermal strength here refers to, for example, the compressive strength after firing at 600 to 1,000°C after putting ore powder and the pellets of the thermal strength-enhancing solidified material of the ore powder into a blast furnace. Currently, ordinary Portland cement is used. The thermal strength of the cured material is about 3-5N/mm ² .

On the other hand, the cold strength refers to the compressive strength immediately before being put into the blast furnace after outdoor curing, and it is usually necessary to be about 3 to 10 N/mm ² .

Non-Patent Document 1: Shigeru Amano, Yukihiro Abe, Kazunari Yamaguchi, Hironao Matsuoka, Masaki Takano, Mio Aida, Kazuyuki Morita, Development of Cement Cold Granulation, Iron and Steel, 77th (1991) No. 6, pages 45-52

Non-Patent Document 2: Masanori Nakano, Masaaki Naito, Kenichi Higuchi, and Koji Morimoto, Non-spherical carbon composite agglomerates: Laboratory-scale fabrication and quality evaluation, ISIJ International, Vol. 44, No. 12, pp. 2079-2085 (2004) (Non -spherical Carbon Composite Agglomerates: Lab-scale Manufacture and Quality Assessment, ISIJ International, Vol.44, No.12, pp.2079～2085(2004))

Patent Document 1: Japanese Patent Application Laid-Open No. 05-171303.

Patent Document 2: Japanese Patent Application Publication No. 05-073707.

Contents of the invention

An object of the present invention is to provide a hot-strength-increased solidified material of ore powder, which has a cold strength equal to or higher than that of conventional ore powder solidified materials and has an excellent hot strength, a pellet using the same, and a method for producing the same.

The present invention is: a kind of ore powder thermal strength enhanced solidification material, which is obtained by mixing any one or two of cement or lime, slag and siliceous substances, and the total amount of CaO, Al ₂ O ₃ and SiO ₂ Among them, the chemical composition is: 3-56% of CaO, 3-40% of Al ₂ O ₃ and 31-86% of SiO ₂ . In the solidified material, the mixing ratio of any one or two of cement or lime, slag and siliceous substance is: 1-76 parts of any one or two of cement or lime, 2-76 parts of slag, silicon 2 to 95 parts of acidic substances. In this cured material, the SiO ₂ component of the siliceous material is 45% or more. The cured material also contains gypsum. In this cured material, gypsum is less than 5 parts in 100 parts of cured material. The cured material also contains a water reducer. In the cured material, the water reducing agent is 0.5-8 parts relative to 100 parts of the cured material. In the cured material, the water reducer contains alkenyl ether represented by R10(A10)mR2 or a copolymer of polyalkenyl ether represented by Z[0(A20)nR3]a and maleic anhydride; wherein, A10 is a carbon atom One or more mixtures of 2 to 3 alkenyloxy groups, when 2 or more types can be added in blocks or randomly; R1 is an alkenyl group with 2 to 5 carbon atoms; R2 It is an alkyl group with 1 to 4 carbon atoms; m is the average added mole number of alkenyloxy groups, which is 20 to 150; Z is the residue of a compound containing 2 to 8 hydroxyl groups; A20 is a carbon atom with 2 to 2 1 or a mixture of 2 or more alkenyloxy groups, and 2 or more types may be added in blocks or randomly; R3 is an alkenyl group with 2 to 5 carbon atoms; n is an alkenyloxy group The average number of moles added is 0 or more than 1; a is 2-8. In addition, the present invention is a pellet containing ore powder, the solidified material, and water. In the pellets, for 100 parts of ore powder, the solidified material is 3 to 20 parts. In the pellets, the ratio of water/(ore powder+the solidified material) is 0.03-0.3. Moreover, this invention is the manufacturing method of this pellet.

According to the present invention, it is possible to provide a hot-strength-enhanced solidified material of ore powder, which has a cold strength equal to or higher than that of conventional ore powder solidified materials, and which is superior in hot strength, as well as a pellet using the material and a production method thereof.

Description of drawings

Fig. 1 is a graph showing the influence of a water reducing agent on room temperature strength and gradual cooling strength (hot strength).

Fig. 2 is a graph showing the effect of gypsum on room temperature strength and gradual cooling strength (hot strength) (when a water reducing agent is added).

Detailed ways

The present invention will be described in detail below.

In addition, in the present invention, parts or % represent a mass basis unless otherwise specified.

The present invention relates to a heat-intensity-enhanced solidified material of ore powder with a specific chemical composition, which is formed by mixing cement, slag and siliceous substances.

The so-called ore powder in the present invention refers to, for example, gold ore, silver ore, copper ore, lead ore, bismuth ore, tin ore, zinc ore, iron ore, iron sulfide ore, chromite, manganese ore, tungsten ore, Molybdenum ore, nickel ore, and cobalt ore are sources of dust, and one or more of these can be used.

The cement used in the present invention is not particularly limited, and ordinary cement can be used. Specifically, various Portland cements such as ordinary, early-strength, super-early-strength, medium-heat, and low-heat, etc. can be mentioned. Among these Portland cements, filler cements such as limestone fine powder are mixed, waste utilization type cements, so-called ecological cement, etc.; one of these cements can be used alone or two or more can be used in combination.

Lime used in the present invention refers to quicklime represented by the chemical formula CaO or slaked lime represented by the chemical formula Ca(OH) ₂ .

Quicklime is not particularly limited, and generally, industrial products having calcium oxide (CaO) of 90% or more can be used, and slaked lime is not particularly limited, and industrial products having calcium oxide (CaO) of 65% or more can be used. They can also be used in combination.

The particle size of lime is represented by a Blaine specific surface area value (hereinafter referred to as Blaine value), and is preferably 2000 cm ² /g or more, more preferably 3000 cm ² /g or more. Outside this range, there is a risk that the cold and hot strength of the cured material will decrease.

Examples of the slag used in the present invention include steelmaking slag such as blast furnace quenched slag or blast furnace annealed slag produced as a by-product when producing pig iron in a blast furnace, and steelmaking slag such as converter slag or electric furnace slag produced in a steelmaking process. Use one or more of them. It is preferable to use blast furnace water-quenched slag from the viewpoint of economy and easy availability.

The particle size of the slag is expressed by the Blaine value, and is preferably 2000 cm ² /g or more, more preferably 3000 cm ² /g or more. Outside this range, there is a risk that the cold and hot strength of the cured material will decrease.

The siliceous substance used in the present invention refers to a material having a _SiO content of 45% or more as a chemical component, for example, silica fume, fly ash, coarse ash (coal ash), pozzolan, diatomaceous earth, Silicate white clay (silicic acid white clay), fused silica, white sand beads (silas pallum), quartz sand, and rice husk ash (chaff ash), etc., and one or more of them can be used. Among them, it is preferable to use fly ash also from the viewpoint of economical efficiency.

The particle shape of the siliceous material is preferably spherical in terms of the filling capacity of the particles and the ease of neck growth during the sintering reaction.

In addition, it is preferable to use a siliceous substance containing as little as possible sodium, potassium, and phosphorus components that may hinder the operation of the blast furnace.

The particle size of the siliceous material is expressed by the Blaine value, and is preferably 2000 cm ² /g or more, and more preferably 3000 cm ² /g or more. Outside this range, there is a risk that the cold and hot strength of the cured material will decrease.

Although the mixing ratio of either or both of cement or lime, slag and siliceous material is not particularly limited, it is preferably: 1 to 76 parts of either or both of cement or lime, and 2 to 95 parts of slag , 2 to 95 parts of siliceous substances. In the case of using cement, more preferably 1 to 76 parts of cement, 2 to 76 parts of slag, and 2 to 95 parts of siliceous substances; particularly preferably 3 to 75 parts of cement, 4 to 74 parts of slag, and 4 to 95 parts of siliceous substances. 85 servings. In the case of using lime, it is more preferably 1-50 parts of lime, 2-95 parts of slag, and 3-95 parts of siliceous material; particularly preferably 2-48 parts of lime, 2-93 parts of slag, and 5-95 parts of siliceous material. 93 copies. Outside this range, there is a possibility that sufficient cold strength and hot strength of the cured material cannot be obtained.

In the present invention, for the purpose of improving the cold strength, any one or both of cement or lime, slag and siliceous substances are mixed to obtain a thermal strength-enhancing solidified material of ore powder, and CaO, Al ₂ O ₃ In the total of SiO 2 and SiO ₂ , the chemical composition is: 3-56% of CaO, 3-40% of Al ₂ O ₃ , and 30-86% of SiO ₂ . Gypsum may be contained in the heat-strength-enhanced cured material of ore powder (hereinafter referred to as the cured material).

Here, examples of gypsum include dihydrate gypsum, hemihydrate gypsum, type II anhydrite, or type III anhydrite. Among them, type II anhydrite and type III anhydrite are preferable.

The content of gypsum is preferably less than 5 parts, more preferably less than 3 parts. If the content of gypsum exceeds this range, there is a danger of a decrease in heat strength.

The particle size of the gypsum, represented by the Blaine value, is preferably 2000 cm ² /g or more, more preferably 3000 cm ² /g or more. Outside this range, there is a risk that the cold and hot strength of the cured material will decrease.

In the present invention, in order to further increase the thermal strength, it is preferable to further use a water reducing agent. The types of water reducers include: alkyl allyl sulfonate, naphthalene sulfonate, formalin condensate of melamine sulfonate, polycarbonate polymer compounds, etc. One or more than two kinds of water reducing agents can also be used in liquid or powder form. Among them, the water reducing agent described below is especially preferred, and the water reducing agent comprises the copolymerization of alkenyl ether represented by R10(A10)mR2 or polyalkenyl ether represented by Z[0(A20)nR3]a and maleic anhydride Among them, A10 is a mixture of one or more than two alkenyloxy groups with 2 to 3 carbon atoms, and two or more types can be added in blocks or randomly; R1 is a carbon number of 2 to 5 alkenyl groups; R2 is an alkyl group with 1 to 4 carbon atoms; m is the average added mole number of alkenyloxy groups, which is 20 to 150; Z is the residue of a compound containing 2 to 8 hydroxyl groups; A20 is one or a mixture of two or more alkenyloxy groups with 2 to 3 carbon atoms, and two or more types can be added in blocks or randomly; R3 is an alkenyl group with 2 to 5 carbon atoms Alkenyl; n is the average added mole number of alkenyloxy, which is 0 or more than 1; a is 2-8.

For 100 parts of cured material, the usage amount of the water reducing agent is preferably 0.5-8 parts, more preferably 1-6 parts. If it is less than 0.5 parts, there will be no effect, and if it exceeds 8 parts, the heat intensity will no longer rise, which is uneconomical, so it is not preferable.

In the present invention, a mixed cement of cement and blast furnace cement as slag, or a mixed cement of cement with silica cement or fly ash cement as a siliceous substance can also be used.

In the chemical composition of the cured material, in the total of _CaO , _Al2O3 and _SiO2 , CaO _is 3-56%, _Al2O3 is 3-40%, and _{SiO2 is} 30-86%; preferably, CaO is 7-45%, Al ₂ O ₃ is 5-35%, and SiO ₂ is 32-76%. Outside this range, there is a risk that the heat strength of the cured material cannot be sufficiently obtained.

The method of mixing these used materials is not particularly limited, and may be premixed before granulation, or each used material may be mixed during granulation.

The particle size of the cured material is expressed by the Blaine value, and is preferably 2000 cm ² /g or more, more preferably 4000 cm ² /g or more. Outside this range, the cured material risks a reduction in cold strength.

For 100 parts of ore powder, the usage amount of the solidifying material is preferably 3-20 parts, more preferably 5-15 parts. If it is less than this range, the cold strength and hot strength may be poor, and if it is more than this range, it is uneconomical, so it is not preferable.

The ratio of water/(ore powder+the solidification material) is not particularly limited, but is preferably 0.03 to 0.3 parts, more preferably 0.05 to 0.2 parts. If it is less than this range, the cold strength may be poor, and the reduction reaction after putting into the blast furnace may be poor. In addition, if it exceeds this range, there is a danger of cracking due to heat shrinkage after firing and a decrease in thermal strength.

In the production of pellets using this solidified material, coke powder may be added in order to improve the reducibility of the pellets charged into the blast furnace.

In addition, one or both of water reducer, high performance water reducer, AE water reducer, fluidizer, viscosifier, shrinkage reducer and coagulation regulator can be used within the scope of not impairing the purpose of the present invention. above.

There are no particular limitations on the method of producing pellets using the solidified material, and in addition to granulation using a drum-type (drum) and pan-type (pan) granulator, for example: pressure molding, wet granulation, etc. Compression molding and extrusion molding, etc.

In addition, the curing method of the produced pellets is not particularly limited, and examples thereof include high-pressure steam curing, steam curing, humid air curing, or heating curing, in addition to normal temperature and normal pressure curing.

Example

Hereinafter, the present invention will be described in further detail based on examples. The present invention is not limited by these Examples.

Experimental example 1

The cement, slag, and siliceous substance shown in Table 1 were mixed to prepare a solidified material having the chemical composition of CaO, Al ₂ O ₃ and SiO ₂ shown in Table 1.

For 100 parts of ore powder, 13 parts of the prepared solidified material were mixed. For a total of 100 parts of the ore powder and the prepared solidified material, 15 parts of water were mixed to prepare a kneaded product.

40mm的金属成型模具中，利用岛津制作所社制、SSP-10A型、FT-IR用压力机，施加7.8MPa的成型压力，保持30秒，然后脱模得到

40×16mm的粒料。Put 50g of the prepared kneading material into

In a 40mm metal molding die, apply a molding pressure of 7.8 MPa using a Shimadzu Corporation, SSP-10A type, FT-IR press, hold it for 30 seconds, and then release the mold to obtain

40 x 16mm pellets.

The prepared pellets were cured by normal temperature and pressure curing method, and the cold strength and hot strength of the pellets were measured. The results are reported together in Table 1.

materials used

Cement a: manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "Ordinary Portland Cement", Blaine value 3150 cm ² /g, specific gravity 3.13, CaO 72%, Al ₂ O ₃ 6%, SiO ₂ 22%.

Slag: Blast furnace slag, manufactured by Nippon Steel Blast Furnace Cement Co., Ltd., trade name "Esment Super-60", Blaine value 6000 cm ² /g, specific gravity 2.91, CaO 49%, Al ₂ O ₃ 16%, _SiO2 35%.

Silicic substance A: Fly ash, produced by coal thermal power plants, JIS Class II product, Blaine value 3700cm ² /g, specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%.

Silicic substance B: fly ash, produced by coal thermal power generation, JIS II product, Blaine value 3700cm ² /g, specific gravity 2.35, CaO 0%, Al ₂ O ₃ 32%, SiO ₂ 68%.

Silicic substance C: fly ash, produced by coal thermal power generation, JIS II product, Blaine value 3700cm ² /g, specific gravity 2.37, CaO 0%, Al ₂ O ₃ 46%, SiO ₂ 54%.

Silicic acid substance D: fused silica, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "DENKA fused silica", BET specific surface area value 11.3 m ² /g, specific gravity 2.26, CaO 0%, Al ₂ O ₃ 0%, SiO ₂ 100%.

Silicic material E: sand powder (true sand powder), manufactured by Izumi Kogyo Co., Ltd., Blaine value 10400 cm ² /g, specific gravity 3.63, CaO 3%, Al ₂ O ₃ 34%, SiO ₂ 63%.

Silicate substance F: γ-2CaO·SiO ₂ , reagent grade calcium carbonate and reagent grade silicon dioxide, mixed with a CaO/SiO ₂ molar ratio of 2.0, fired in an electric furnace at a temperature of 1500°C into synthetically obtained. The obtained fired product was cooled to have a Brain value of 6000 cm ² /g, a specific gravity of 3.01, 63% of CaO, 2% of Al ₂ O ₃ , and 35% of SiO ₂ .

Ore powder: iron ore powder, hematite, specific gravity 4.95, sieved less than 3mm.

Water: tap water.

maintenance method

Curing at normal temperature and pressure: After the pellets are prepared, put them into plastic bags and seal them with rubber tapes, and cure them for 14 days at an atmospheric pressure of 20°C.

test methods

Cold strength: The prepared pellets were cured at room temperature at 20°C under normal temperature and pressure, and the compressive strength at a material age of 14 days was measured.

Thermal strength: The prepared pellets are cured at room temperature and pressure at 20°C. When the material is 14 days old, it is fired under the following conditions: in a nitrogen atmosphere, the temperature is raised to a maximum temperature of 860 at a rate of 10°C/min. ℃. After reaching the highest temperature, it was taken out of the furnace, and the compressive strength was measured.

Table 1

Cement, slag and siliceous substances in parts

It can be seen from Table 1 that the heat strength of the ore powder of the present invention is enhanced and cured material (the cured material), and the heat strength is significantly improved.

That is, the cured material exhibited the same or higher cold strength than the examples and had excellent hot strength by properly mixing cement, slag, and siliceous substance.

Curing with a chemical composition within the scope of _the present invention (in the total of CaO, _Al2O3 and _SiO2 , CaO is 3-56%, _Al2O3 is _3-40 %, _SiO2 is 30-86%) The pellets of the material are excellent in cold strength and hot strength (experiments 1-2 to 1-6, 1-9 to 1-13, 1-15 to 1-20, 1-22, 1-23). If the CaO is less than 3%, the hot strength is high and the cold strength is extremely low (Experiment 1-1), if the CaO exceeds 56%, the cold strength is high and the hot strength is insufficient (Experiment 1-7), if _Al2O3 is less than ₃ %, high hot strength and low cold strength (Experiment 1-8), if _Al2O3 exceeds 40%, both cold strength and hot strength are low (Experiment 1-14), if _{SiO2 is} less than 30%, cold strength is high While the hot strength is insufficient, if SiO ₂ exceeds 86%, both the cold strength and the hot strength are low (Experiments 1-21), therefore, the chemical composition of the cured material is preferably within the above-mentioned range.

Experimental example 2

Except that the cement, slag, and siliceous substance shown in Table 2 were mixed, it was the same as Experimental Example 1. The results are reported together in Table 2.

Table 2

Cement, slag and siliceous substances in parts

As can be seen from the results in Table 2, this cured material is excellent in improving the thermal strength.

That is, the cured material exhibited the same or higher cold strength than the comparative example and had excellent hot strength by appropriately mixing cement, slag, and siliceous substance.

Experimental example 3

Except that the cement, slag, and siliceous substance shown in Table 3 were mixed, it was the same as Experimental Example 1. The results are reported together in Table 3.

materials used

Cement b: medium heat Portland cement, manufactured by Denka Kagaku Kogyo Co., Ltd., trade name "DENKA (DENKA) medium heat Portland cement", Blaine value 3050 cm ² /g, specific gravity 3.20, CaO 70%, Al ₂ O ₃ 4%, SiO ₂ 26%.

Cement c: Low heat Portland cement, manufactured by Pacific Cement Co., trade name "Low heat Portland cement", Blaine value 3470 cm ² /g, specific gravity 3.21, CaO 69%, Al ₂ O ₃ 3%, SiO ₂ 28% .

Blast furnace cement: manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "DENKA blast furnace cement", Blaine value 3970 cm ² /g, specific gravity 3.05, CaO 63%, Al ₂ O ₃ 9%, SiO ₂ 28%.

Fly ash cement: manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "DENKA (DENKA) Fly Ash Cement (Class B)", Blaine value 3500 cm ² /g, specific gravity 2.96, CaO 71%, Al ₂ O ₃ 5%, SiO ₂ 24%.

table 3

Cement, slag and siliceous substances are in parts, *1 is a mixture of 75 parts of blast furnace cement and 25 parts of siliceous substances, *2 is a mixture of 10 parts of fly ash cement and 90 parts of slag

As can be seen from the results in Table 3, the heat-strength-enhanced cured material of the present invention is excellent in improving heat strength regardless of the type of cement. In addition, the effects of the present invention can be achieved by appropriately mixing blast furnace cement, siliceous material, fly ash cement, and slag.

Experimental example 4

Except that the cement, slag, siliceous substance, and gypsum shown in Table 4 were mixed, it was the same as Experimental Example 1. The results are reported together in Table 4.

materials used

Anhydrous gypsum: produced in Thailand, type II natural anhydrous gypsum, Blaine value 8100cm ² /g, specific gravity 2.94, CaO 95%, Al ₂ O ₃ 2%, SiO ₂ 3%.

Table 4

Cement, slag, siliceous substances and gypsum in parts

It can be seen from the results in Table 4 that the cured material can increase the cold strength because it contains an appropriate amount of gypsum.

That is, the heat-strength-enhanced cured material of the present invention can improve the cold strength compared with the comparative example by appropriately mixing cement, slag, siliceous substance, and gypsum, and is also excellent in the expression of hot strength.

Experimental example 5

Use 32 parts of cement A, 44 parts of slag and 24 parts of siliceous substance A to prepare the solidified material. The amounts shown in Table 1 were mixed with respect to 100 parts of iron ore powder. Other than that, it is the same as Experimental Example 1. The results are reported together in Table 5.

table 5

Experiment serial number cured material Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 5-15-25-35-45-55-6 035101520 41314172631 31011131923 Comparative Example Example Example Example Example Example Example Example

The solidified material is the number of parts relative to the amount of ore powder in 100 parts

From the results in Table 5, it can be seen that the solidified material exhibits the same or higher cold strength than that of the comparative example due to the appropriate amount of ore powder mixed in the solidified material, and also has excellent hot strength performance.

Experimental example 6

Use 32 parts of cement A, 44 parts of slag and 24 parts of siliceous substance A to prepare the solidified material. For 100 parts of iron ore powder, 13 parts of the prepared solidified material were mixed. For a total of 100 parts of the ore powder and the prepared solidified material, water shown in Table 6 was mixed. Other than that, it is the same as Experimental Example 1. The results are reported together in Table 6.

Table 6

Experiment serial number water Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 6-16-26-36-46-5 0.030.050.10.20.3 2925211814 2421181311 Example Example Example Example Example Example Example

The amount of water is relative to the mass % of the total of the ore powder and the solidified material

It can be seen from the results in Table 6 that the cured material can increase the thermal strength because the ratio of water/(ore powder+the cured material) is in an appropriate range.

That is, by mixing cement, slag, and siliceous substances, and having an appropriate ratio of water/(ore powder + the solidified material), the hot strength-enhanced solidified material of the present invention exhibits the same or higher cold strength than the comparative example , and the performance of thermal strength is excellent.

Experimental example 7

Use 32 parts of cement A, 44 parts of slag and 24 parts of siliceous substance A to prepare the solidified material. For 100 parts of iron ore powder, 13 parts of the prepared solidified material were mixed. For a total of 100 parts of iron ore powder and the prepared solidified material, 15 parts of water were mixed to prepare pellets.

Curing was carried out according to the curing method after granulation of the prepared pellets shown in Table 7. Other than that, it is the same as Experimental Example 1. The results are reported together in Table 7.

maintenance method

Steam curing: After the pellets are prepared, they are first placed for 2 hours, and then steam curing is carried out under the following conditions: heating at a rate of 15°C/min, and maintaining at a maximum temperature of 70°C for 3 hours. On the second day, it was taken out from the curing tank and cured for 13 days in an environment of 20°C.

High-pressure steam curing: After the pellets are prepared, put them into a gas pressure container and cure them for 6 hours under the conditions of a steam pressure of 10 atmospheres and a temperature of 170°C. After curing, it is maintained for up to 14 days at a room temperature of 20°C.

Moist air curing: After the pellets are prepared, they are cured for 14 days in a room temperature environment with a humidity of 100% and 20°C.

Heating curing: After the pellets are prepared, they are cured in a sealed state at room temperature of 20°C for 1 day. After curing for 1 day in a room temperature environment of 20° C., it was cured for 13 days in a dryer at 40° C.

Table 7

Experiment serial number maintenance method Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 1-57-17-27-37-4 Normal temperature and pressure curing Steam curing High pressure steam curing Humid air curing Heating curing 2023262122 1619171517 Example Example Example Example Example Example Example

From the results in Table 7, it can be seen that the cured material, regardless of the curing method, has excellent hot strength.

Experimental example 8

Mix 50 parts of cement a, 40 parts of slag, 10 parts of siliceous substance A and 1 part of anhydrite, and add water reducing agent in different ways in terms of solids: 0, 0.6, 1.2, 3.0 parts by mass (the addition rate in the form of aqueous solution Each: 0, 1.0, 2.0, 5.0 parts by mass). Other than that, it is the same as Experimental Example 4. The strength measurement results are shown in Table 8. In addition, the effect of water reducer on cold strength and hot strength is shown in Figure 1.

materials used

Water reducer: commercially available, copolymer of polyalkenyl ether and maleic anhydride, 60% aqueous solution.

Table 8

Experiment serial number Water reducing agent Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 8-18-28-38-4 01.02.05.0 14181625 57811 EXAMPLES EXAMPLES EXAMPLES EXAMPLES

The amount of water reducing agent is the number of parts relative to 100 parts of assimilated materials

It can be seen from Table 8 and Figure 1 that, in the case of adding water reducer, the cold strength and hot strength of the cured material increase simultaneously with the increase of the addition rate. That is, the heat-strength-increased cured material of the present invention can improve the cold strength compared with the comparative example by appropriately mixing cement, slag, siliceous substance, gypsum, and water reducer, and is also excellent in the expression of hot strength.

Experimental example 9

Mix 50 parts of cement a, 40 parts of slag, 10 parts of siliceous substance A and 1 part of water reducer (solid matter), and the mixing amount of anhydrite is 0, 1, 2, 3 parts respectively. Other than that, it is the same as Experimental Example 8. The strength measurement results are shown in Table 9. In addition, the effect of gypsum on cold strength and hot strength (in the case of adding a water reducing agent) is shown in Figure 2.

Table 9

Experiment serial number plaster Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 9-19-29-39-4 0123 17181617 6787 EXAMPLES EXAMPLES EXAMPLES EXAMPLES

The amount of plaster is in parts relative to 100 parts of the cured material

It can be seen from Table 9 and Figure 2 that when adding a water reducer, the heat intensity increases before the mixing amount of anhydrous gypsum is 2 parts, and after 3 parts or more, it no longer has the effect.

Experiment 10

Lime, slag, and siliceous substances were mixed as shown in Table 10 to prepare solidified materials containing the chemical compositions of CaO, Al ₂ O ₃ , and SiO ₂ shown in Table 10. Other than that, it is the same as Experimental Example 1. The results are reported together in Table 10.

materials used

Lime a: Quick lime, manufactured by Wako Pure Chemical Industries, Ltd., reagent grade, pulverized product, Blaine value 6000 cm ² /g, specific gravity 3.31, CaO 100%, Al ₂ O ₃ 0%, SiO ₂ 0%.

Table 10

Lime, slag and siliceous substances in parts

As can be seen from the results in Table 10, the cured material is excellent in improving the thermal strength.

That is, this solidified material exhibits the same or higher cold strength than the comparative example by appropriately mixing lime, slag, and siliceous substance, and is also excellent in hot strength expression.

Use a chemical composition within the scope of the present invention (in the total of CaO, _Al2O3 and _SiO2 , CaO _is 3 to 56%, _Al2O3 is ₃ to 40%, and _SiO2 is 30 to 86%). The pellets of the cured material are excellent in cold strength and hot strength (experiments 10-2 to 10-6, 10-9 to 10-13, 10-16 to 10-20, 10-22, 10-23). In contrast, if CaO is less than 3%, the hot strength is high and the cold strength is extremely low (Experiment 10-1), if the CaO exceeds 56%, the cold strength is high and the hot strength is insufficient (Experiment 10-7), and if _{Al2O 3} Less than 3% or more than 40%, the hot strength is high and the cold strength is low (experiment 10-8, experiment 10-14), if the SiO ₂ is less than 30%, the cold strength is high and the hot strength is insufficient (experiment 10-15) , if SiO ₂ exceeds 86%, the hot strength is high and the cold strength is extremely low (Experiments 10-21), therefore, the chemical composition of the cured material is preferably within the above-mentioned range.

Experiment 11

Except that lime, slag and siliceous substance were mixed as shown in Table 11, the others were the same as Experimental Example 10. The results are reported together in Table 11.

Materials used

Lime b: Slaked lime, manufactured by Wako Pure Chemical Industries, Ltd., reagent grade, pulverized product, Blaine value 6000 cm ² /g, specific gravity 2.08, CaO 100%, Al ₂ O ₃ 0%, SiO ₂ 0%.

Table 11

Lime, slag and siliceous substances in parts

As can be seen from the results in Table 11, the cured material is excellent in improving the thermal strength.

That is, this solidified material exhibits the same or higher cold strength than the comparative example by appropriately mixing lime, slag, and siliceous substance, and is also excellent in hot strength expression.

Experiment 12

Except that lime, slag and siliceous substance were mixed as shown in Table 12, the others were the same as Experimental Example 10. The results are reported together in Table 12.

Materials used

Table 12

Lime, slag and siliceous substances in parts

As can be seen from the results in Table 12, the cured material is excellent in improving the thermal strength.

That is, this solidified material exhibits the same or higher cold strength than the comparative example by appropriately mixing lime, slag, and siliceous substance, and is also excellent in hot strength expression.

Experiment 13

Except that lime, slag and siliceous substance were mixed as shown in Table 13, the others were the same as Experimental Example 10. The results are reported together in Table 13.

Table 13

Lime, slag and siliceous substances in parts

As can be seen from the results in Table 13, the cured material is excellent in improving the thermal strength.

That is, this solidified material exhibits the same or higher cold strength than the comparative example by appropriately mixing lime, slag, and siliceous substance, and is also excellent in hot strength expression.

Experiment 14

Except that lime, slag, siliceous substance and gypsum were mixed as shown in Table 14, the others were the same as Experimental Example 10. The results are reported together in Table 14.

Materials used

Anhydrous gypsum: produced in Thailand, type II natural anhydrous gypsum, Blaine value 8100cm ² /g, specific gravity 2.94, CaO 95%, Al ₂ O ₃ 2%, SiO ₂ 3%.

Table 14

Lime, slag, siliceous substances and gypsum in parts

It can be seen from the results in Table 14 that the cured material can increase the cold strength because it contains an appropriate amount of gypsum.

That is, the heat-strength-enhanced cured material of the present invention can improve the cold strength compared with the comparative example by appropriately mixing lime, slag, siliceous substance, and gypsum, and is also excellent in the expression of hot strength.

Experiment 15

Use 3 parts of lime A, 27 parts of slag and 70 parts of siliceous substance A to prepare the solidified material. For 100 parts of ore powder, the amounts shown in Table 15 were mixed. Other than that, it is the same as Experimental Example 10. The results are reported together in Table 15.

Table 15

Experiment serial number cured material Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 15-115-215-315-415-515-6 035101520 41413152432 3910131821 Comparative Example Example Example Example Example Example Example Example

The amount of solidified material is the number of parts relative to 100 parts of ore powder

From the results in Table 15, it can be seen that the solidified material exhibits the same or higher cold strength as that of the comparative example due to an appropriate amount of ore powder being mixed, and has excellent hot strength performance.

Experiment 16

Use 3 parts of lime A, 27 parts of slag and 70 parts of siliceous substance A to prepare the solidified material. For 100 parts of ore powder, 13 parts of the prepared solidified material were mixed. For a total of 100 parts of the ore powder and the prepared solidified material, water shown in Table 16 was mixed. Other than that, it is the same as Experimental Example 10. The results are reported together in Table 16.

Table 16

Experiment serial number water Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 16-116-216-316-416-5 0.030.050.10.20.3 2521171413 211815139 Example Example Example Example Example Example Example

The amount of water is a percentage relative to the total of the ore powder and the solidified material.

It can be seen from the results in Table 16 that the cured material can increase the thermal strength because the ratio of water/(ore powder+the cured material) is in an appropriate range.

That is, by mixing lime, slag, and siliceous substances so as to have an appropriate ratio of water/(ore powder+the solidified material), the thermal strength-enhanced solidified material of the present invention shows the same or higher cold Strength, and the performance of hot strength is excellent.

Experiment 17

Use 3 parts of lime A, 27 parts of slag and 70 parts of siliceous substance A to prepare the solidified material. For 100 parts of ore powder, 13 parts of the prepared solidified material were mixed. For a total of 100 parts of the ore powder and the prepared solidified material, 15 parts of water were mixed to prepare pellets.

According to the curing method after granulation of the prepared pellets shown in Table 17, curing (various conditions of steam curing, high-pressure steam curing, humid air curing, and heating curing are the same as in Example 7). Other than that, it is the same as Experimental Example 10. The results are reported together in Table 17.

Table 17

Experiment serial number maintenance method Cold strength (N/mm ² ) Hot strength (N/mm ² ) Remark 10-417-117-217-317-4 Normal temperature and pressure curing Steam curing High pressure steam curing Humid air curing Heating curing 1618211618 1417151415 Example Example Example Example Example Example Example

As can be seen from the results in Table 17, the cured material has excellent hot strength regardless of the curing method.

Industrial availability

The hot strength enhanced solidified material of ore powder of the present invention not only has the same cold strength as the previous solidified material, but also has good hot strength, and can be applied in ironworks, steelworks and non-ferrous metal refineries, etc. Granulation of generated or collected dust.

Claims (14)

1. A heat-strength enhanced solidification material of ore powder is characterized in that it is obtained by mixing any one or both of cement or lime, slag and siliceous substances, and is obtained by mixing CaO, Al ₂ O ₃ and SiO ₂ In total, the chemical composition is: CaO 3-56%, Al ₂ O ₃ 3-40%, SiO ₂ 30-86%. 2. The heat-strength enhanced solidification material of ore powder according to claim 1, characterized in that, the mixing ratio of any one or both of said cement or lime, slag and siliceous matter is: cement or lime Any one or two is 1-76 parts, slag is 2-95 parts, and siliceous substance is 2-95 parts. 3. The heat-strength-increased solidified material of ore powder according to claim 1, wherein the SiO ₂ component of the siliceous material is 45% or more. 4. The heat-strength enhanced solidified material of ore powder according to claim 1, further comprising gypsum. 5. The thermal strength-enhanced solidified material of ore powder according to claim 4, characterized in that, in 100 parts of the aforementioned solidified material, the aforementioned gypsum is less than 5 parts. 6 . The heat-strength enhanced solidified material of ore powder according to claim 1 , further comprising a water reducer. 6 . 7 . The heat-strength-enhancing cured material of ore powder according to claim 6 , characterized in that, relative to 100 parts of the aforementioned cured material, the amount of the aforementioned water reducing agent is 0.5-8 parts. 8. The heat-strength enhanced solidified material of ore powder according to claim 6, wherein the water reducing agent comprises alkenyl ether represented by R10(A10)mR2 or represented by Z[0(A20)nR3]a Represented polyalkylene ethers, and copolymers of maleic anhydride; Among them, A10 is one or a mixture of two or more alkenyloxy groups with 2 to 3 carbon atoms, and two or more types can be added in blocks or randomly; R1 is an alkenyl group with 2 to 3 carbon atoms. 5 alkenyl groups; R2 is an alkyl group with 1 to 4 carbon atoms; m is the average number of moles of alkenyloxy groups added, which is 20 to 150; Z is the residue of a compound containing 2 to 8 hydroxyl groups; A20 is one or a mixture of two or more alkenyloxy groups with 2 to 3 carbon atoms, and two or more can be added in a block or without R3 is an alkenyl group with 2 to 5 carbon atoms; n is the average number of moles of alkenyloxy groups added, which is 0 or more than 1; a is 2 to 8. 9. A granular material, characterized in that it contains: ore powder, the thermal strength enhancing solidification material of ore powder according to any one of claims 1 to 8, and water. 10. The pellet according to claim 9, characterized in that the amount of the solidified material is 3 to 20 parts relative to 100 parts of ore powder. 11. The pellet according to claim 9, characterized in that the ratio of water/(ore powder+the aforementioned solidified material) is 0.03-0.3. 12. A method for producing pellets, characterized in that the material obtained by mixing ore powder, the thermal strength enhancing solidification material of ore powder according to any one of claims 1 to 8, and water is formed into pellets , for maintenance. 13. The method for producing pellets according to claim 12, wherein 3 to 20 parts of the solidified material are mixed with respect to 100 parts of the ore powder. 14. The method for producing pellets according to claim 12, wherein the ratio of water/(ore powder+the solidified material) is 0.03 to 0.3.

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