JP2010047794A - Solidifying material for enhancing hot strength for ore powder, pellet of ore powder using the same, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solidifying material for enhancing hot strength for ore powder which ensures the cold strength of a pellet which is equal to or higher than that obtained by the conventional solidifying material, and is also excellent in development of the hot strength and wear resistance of the pellet, to provide a pellet using the same, and to provide a method for producing the same. <P>SOLUTION: Disclosed are: the solidifying material for enhancing hot strength for ore powder, which contains portland cement and a pozzolana reactive substance and does not contain slag, wherein the specific surface area of the pozzolana reactive substance is ≥2,500 cm<SP>2</SP>/g, and the pozzolana reactive substance is fly ash; the solidifying material for enhancing hot strength for ore powder, wherein the cement is high early strength portland cement; and the solidifying material for enhancing hot strength for ore powder, wherein alkanolamine is contained. Also disclosed are the pellet using the solidifying material for enhancing hot strength for ore powder and a method for producing the same. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hot-strength solidified material for ore powder used for pelletizing ore powder generated at ironworks, steelworks, non-ferrous smelters, and the like, a pellet of ore powder using the same, and a method for producing the same.

  Conventionally, pelletizing of ore powder has been carried out against the background of effective utilization of ore powder such as dust generated in factories such as steelworks, steelworks, and non-ferrous smelters, and the depletion of high-quality mineral resources.

  Known pelletizing methods for ore powder include a firing pellet method in which a drum-type or pan-type pelletizer is used for firing after pelletizing, and a cold pellet method in which the firing step is omitted for the purpose of energy saving.

  The ore powder solidifying material used in the pelletizing method of these ore powders is usually a solidified material made of Portland cement, a solidified material made of quick lime and blast furnace slag, a solidified material made of calcium aluminate compound and a fine powdered inorganic material, ordinarily. Solidified materials composed of Portland cement and calcium aluminate, and solidified materials composed of fly ash and calcium chloride are known (see Non-patent Document 1, Non-patent Document 2, Non-patent Document 3, Patent Document 1, and Patent Document 2). .

Compressive strength (hot strength) after firing pellets using ore powder and its solidified material with increased hot strength into a blast furnace and firing at 600-1000 ° C is about 3 for solidified materials using conventional ordinary Portland cement. it is a ~5N / mm ^2. Moreover, after curing outdoors, the compressive strength (cold strength) immediately before charging into the blast furnace is usually required to be about 3 to 10 N / mm ² . Sintered ore is used as an iron-making raw material as well as pellets, but its hot strength is quantified by a reduced pulverization index indicating wear resistance, and the reduced pulverization index is After firing at 600 to 1000 ° C., the content is 2 to 35% by mass.

  Further, cement admixtures containing fly ash and trialkanolamine are known (see Patent Document 3 and Patent Document 4). These admixtures are for the purpose of improving the initial strength of the concrete, and are different from the problems relating to the improvement of the hot strength which the present invention intends to solve.

Shigeru Amano, Yukihiro Abe, Kazunari Yamaguchi, Hironao Matsuoka, Masaichi Takano, Mio Aida, Kazuyuki Morita, Development of Cementless Cold Pellet, Iron and Steel, 1977 (No. 6), pp. 45-52 Masanori Nakano, Masaaki Naito, Kenichi Higuchi and Koji Morimoto, Non-spherical Carbon Composite Aggregates: Lab-scalar Manufacture and QA. 44, no. 12, pp. 2079-2085 (2004) T.A. C. EISELE and S.E. K. KAWATRA, A REVIEW OF BINDERS IN IRON ORE PELLETIZATION, Mineral Processing & Extractive Metal. Rev. , Vol. 24, pp. 1-90 (2003) Japanese Patent Laid-Open No. 05-171303 Japanese Patent Publication No. 05-073707 Japanese Patent Publication No.54-43008 JP 2000-281403 A

  The present invention is an ore powder hot strength enhanced solidified material having a cold strength equal to or higher than that of a conventional ore powder solidified material and excellent in hot strength expression and wear resistance. Provided pellets and a method for producing the same.

The present invention
(1) A hot-strength enhanced solidified material of ore powder containing no slag, comprising 70 to 90 parts of Portland cement and 10 to 30 parts of pozzolanic reactive material,
(2) The hot-strength enhanced solidified material according to (1), wherein the pozzolanic reactive material is fly ash,
(3) The hot-strength enhanced solidified material according to (1) or (2), wherein the specific surface area of the pozzolanic reactive material is 2500 cm ² / g or more,
(4) The hot strength enhanced solidified material according to any one of (1) to (3), wherein Portland cement is early-strength Portland cement;
(5) The hot strength enhanced solidified material according to any one of (1) to (4), which contains alkanolamine,
(6) The hot-strength enhanced solidified material according to (6), wherein the content of alkanolamine is 0.1 to 20 parts with respect to 100 parts of the pozzolanic reactive substance,
(7) The hot strength-enhancing solidified material of the ore powder according to any one of (1) to (6), comprising a water reducing agent,
(8) The hot strength-enhancing solidifying material of ore powder according to (7), wherein the water reducing agent is 0.5 to 8 parts in solid content with respect to 100 parts of the solidifying material,
(9) The water reducing agent is R1O (A1O) mR2 [wherein A1O is one or a mixture of two or more oxyalkylene groups having 2 to 3 carbon atoms. Or R1 is an alkenyl group having 2 to 5 carbon atoms, R2 is an alkyl group having 1 to 4 carbon atoms, and m is an average addition mole number of an oxyalkylene group of 20 to 150. And Z [O (A2O) nR3] a [wherein Z is a residue of a compound containing 2 to 8 hydroxyl groups, and A2O is an oxyalkylene group having 2 to 3 carbon atoms. 1 type or a mixture of 2 or more types, and when 2 types or more, they may be added in blocks or randomly, R3 is an alkenyl group having 2 to 5 carbon atoms, and n is an oxyalkylene group The average number of moles added is 0 or (7) or (8) a hot strength enhanced solidified material of ore powder comprising a copolymer of a polyalkenyl ether represented by formula (1) and a is 2 to 8, and maleic anhydride ,
(10) Ore powder, a hot strength-enhancing solidifying material of ore powder of any one of (1) to (9), and pellets comprising water,
(11) The pellet according to claim 10, wherein the solidifying material is 3 to 20 parts with respect to 100 parts of ore powder.
(12) Pellets of (10) or (11) having a water / (ore powder + hot strength enhanced solidifying material) ratio (mass) of 0.03 to 0.3,
(13) Ore powder, a hot strength-enhancing solidifying material of ore powder of any one of (1) to (9), and a mixture of water, pelletized and cured pellet manufacturing method,
(14) The manufacturing method of the pellet of Claim 13 which mixes 3-20 parts of solidification materials with respect to 100 parts of ore powders.
(15) The method for producing pellets of (13) or (14), wherein the water / (ore powder + solidifying material) ratio (mass) is 0.03 to 0.3.
It is.

  According to the ore powder hot solidified material according to the present invention, the pellets using the same and the manufacturing method thereof, the cold strength is equal to or higher than that of the conventional solidified material, and the development of the hot strength and resistance Ore powder pellets with excellent wear properties are obtained.

Hereinafter, the present invention will be described in detail.
In the present invention, “parts” and “%” are based on mass unless otherwise specified.

  The present invention relates to a hot-strength enhanced solidified material (hereinafter referred to as the present solidified material) of ore powder having a specific chemical composition blended with Portland cement, pozzolanic reactive material, and alkanolamine.

  The ore powder as used in the present invention refers to, for example, gold ore, silver ore, copper ore, lead ore, lead ore, tin ore, zinc ore, iron ore, sulfide ore, chromium iron ore, manganese ore, tungsten ore, molybdenum ore, nickel ore, Moreover, the dust which uses cobalt ore as a generation source is pointed out, and 1 type, or 2 or more types of these can be used.

  The Portland cement used in the present invention includes various types of Portland cements such as normal, early strength, very early strength, moderate heat, and low heat, filler cement obtained by mixing fly ash, etc. with these Portland cements, and waste-use type cement. So-called eco-cement can be used, and one or more of these can be used in combination. It is preferable to use early-strength Portland cement because of its cold strength. In addition, since fly ash cement contains fly ash, which is a pozzolanic reactive substance, only ash alcohol cement or alkanolamine is added to fly ash cement without blending pozzolanic reactive substance. It is also possible to use it.

  It is not preferable to use slag in combination with the solidified material because it increases the reduced powder index of the ore powder pellets. The slag referred to in the present invention refers to steelmaking slag such as blast furnace granulated slag and blast furnace slow-cooled slag generated as by-products when producing pig iron in a blast furnace, converter slag and electric furnace slag generated in a steelmaking process. Blast furnace cement obtained by mixing granulated blast furnace slag with Portland cement is not used in the present invention.

The pozzolan-reactive substance used in the present invention is a substance that does not have hydraulic properties per se but reacts with calcium hydroxide produced by the hydration reaction of Portland cement to produce a calcium silicate hydrate. Examples include fly ash, silica fume, rice husk ash, coarse ash (coal ash), volcanic ash, diatomaceous earth, silicate white clay, fused silica, shirasu balloon, and rice husk ash (rice husk ash). Of these, one or more of them can be used, and among these, the use of fly ash is preferable from the viewpoint of economy. The particle shape of the pozzolanic reactive material is preferably spherical from the viewpoint of particle filling properties and ease of neck growth during the sintering reaction. In addition, it is preferable to use a pozzolanic reactive material that contains as little sodium, potassium, and phosphorus components as possible during blast furnace operation.
The particle size of the pozzolanic reactive material, Blaine specific surface area (hereinafter, referred to as Blaine value) is preferably not less than ^{2500cm 2 / g, 3000cm 2 /} g or more is more preferable. Outside this range, the expression of cold strength and hot strength may decrease. In view of improving the hot strength, the pozzolanic reactive material is preferably pulverized in advance.

  The blending ratio of the Portland cement and the pozzolanic reactive material is not particularly limited, but 70 to 90 parts of the Portland cement and 10 to 30 parts of the pozzolanic reactive material are preferable, and 75 to 85 parts of the Portland cement and the pozzolanic reactive material. 15-25 parts is more preferable. Outside this range, cold strength and hot strength may not be sufficiently obtained.

In the present invention, for the purpose of improving the hot strength, alkanolamine can be used for the hot-strength enhanced solidified material composed of Portland cement and a pozzolanic reactive substance.
The alkanolamine used in the present invention is an organic compound having an N—R—OH structure in the structural formula. Here, R is an atomic group called an alkyl group or an allyl group, for example, a linear alkyl group such as a methylene group, an ethylene group, and an n-propylene group, an alkyl group having a branched structure such as an isopropyl group, In addition, an allyl group having an aromatic ring such as a phenyl group or a benzyl group can be used.
R may be bonded to the nitrogen atom at two or more positions, and a part or all of R may have a cyclic structure.
Furthermore, R may be bonded to a plurality of hydroxyl groups, and an element other than carbon or hydrogen, for example, sulfur, fluorine, chlorine, oxygen, or the like may be included in part of the alkyl group.
Examples of such alkanolamines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine, N, N-dibutylethanolamine, N- (2-aminoethyl) ethanolamine. , Boron trifluoride triethanolamine, and derivatives thereof. In the present invention, one or more of these can be used.

  The blending ratio of the alkanolamine and the solidifying material is not particularly limited, but is preferably 0.1 to 20 parts of alkanolamine with respect to 100 parts of the pozzolanic reactive material contained in the solidifying material, 0.5 to 15 parts is more preferred. Outside this range, cold strength and hot strength may not be sufficiently obtained.

In the present invention, it is preferable to further use a water reducing agent in order to further improve the hot strength.
Examples of water reducing agents include alkylallyl sulfonates, naphthalene sulfonates, formalin condensates of melamine sulfonates, polycarboxylic acid polymer compounds, and the like, one or more of these water reducing agents. Both liquid and powder can be used.
Among them, R1O (A1O) mR2 [wherein A1O is one or a mixture of two or more oxyalkylene groups having 2 to 3 carbon atoms, and when it is two or more, it may be added in blocks. R1 is an alkenyl group having 2 to 5 carbon atoms, R2 is an alkyl group having 1 to 4 carbon atoms, and m is an average addition mole number of an oxyalkylene group of 20 to 150]. An alkenyl ether and Z [O (A2O) nR3] a [wherein Z is a residue of a compound containing a hydroxyl group having 2 to 8 and A2O is one or two oxyalkylene groups having 2 to 3 carbon atoms In a mixture of two or more species, when two or more species are added, they may be added in blocks or randomly, R3 is an alkenyl group having 2 to 5 carbon atoms, and n is an average addition mole of an oxyalkylene group. 0 or more in number It is preferable to use a water reducing agent comprising a copolymer of a polyalkenyl ether represented by the formula (a is 2 to 8) and maleic anhydride.

  The amount of water reducing agent used is preferably 0.5 to 8 parts, more preferably 1 to 6 parts, based on 100 parts of the solidified material in terms of solid content. If it is less than 0.5 part, there is no effect, and if it exceeds 8 parts, there is little improvement in hot strength, which is uneconomical.

  The method of mixing these materials used is not particularly limited. When the cement clinker is pulverized into Portland cement, it is mixed and pulverized with a pozzolanic reactive substance, or each material is mixed with ore powder when producing pellets. And the like.

  3-20 parts are preferable with respect to 100 parts of ore powder, and, as for the usage-amount of this solidification material, 5-15 parts are more preferable. If it is less than this range, the developability of cold strength and hot strength may be poor, and if it exceeds this range, it becomes uneconomical, which is not preferable.

  The ratio of water / (ore powder + solidified material) is not particularly limited, but is preferably 0.03 to 0.3, more preferably 0.05 to 0.2 in terms of mass ratio. If it is less than this range, the cold strength may be poor, and the reduction reaction after charging into the blast furnace may be poor. If this range is exceeded, cracks due to thermal shrinkage may occur after firing, resulting in a decrease in hot strength.

In the production of pellets using the solidified material, coke powder can be added in order to improve the reducibility of the pellets after being put into the blast furnace. In addition, diethylene glycol can be added for the purpose of improving the initial strength immediately after pelletizing.
Furthermore, 1 type, or 2 or more types can be used in the range which does not inhibit the objective of this invention among a quick setting agent, a thickener, a shrinkage reducing agent, a setting regulator.

  The manufacturing method of the pellet using this solidification material is divided roughly into a pelletizing process and a curing process. The pelletizing method is not particularly limited, and examples thereof include a pressure molding method, a wet pressure molding method, and an extrusion molding method in addition to pelletizing using a drum type or bread type granulator.

  Moreover, the curing method of pelletized pellets is not particularly limited, and examples include autoclave curing, steam curing, wet air curing, and heat curing in addition to normal temperature and normal pressure curing.

  Hereinafter, the present invention will be described in more detail based on experimental examples, but the present invention is not limited thereto.

"Experiment 1"
A solidified material was prepared by blending Portland cement and a pozzolanic reactive material shown in Table 1. 13 parts of the prepared solidifying material was mixed with 100 parts of the ore powder, and 15 parts of water was mixed with 100 parts of the total of the ore powder and the prepared solidifying material to prepare a kneaded product. 50 g of the prepared kneaded material is packed in a φ40 mm mold forming die, and is held for 30 seconds using a Shimadzu Corporation, SSP-10A type, FT-IR press with a molding pressure of 7.8 MPa, After holding, the mold was removed, and pellets of φ40 × 16 mm were pelletized.
The pelletized pellet was cured by normal temperature and normal pressure curing, and the cold strength and hot strength of the pellet were measured. The results are also shown in Table 1.

<Materials used>
Portland cement A: Hayashi Portland cement, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denka Hayao Portland cement”, brain value 4500 cm ² / g, specific gravity 3.12, CaO 72%, Al ₂ O ₃ 5%, SiO ₂ 23%
Portland cement B: Ordinary Portland cement, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denka ordinary Portland cement”, brain value 3150 cm ² / g, specific gravity 3.13, CaO 72%, Al ₂ O ₃ 6%, SiO ₂ 22%
Pozzolanic reactive substance Lee -a: fly ash, coal-fired power artifact, JIS II type Compliant, Blaine value 3700 cm ² / g, specific gravity _{2.35, CaO 6%, Al 2} O 3 27%, SiO 2 67%
Granulated blast furnace slag: manufactured by Nippon Steel Blast Furnace Cement Co., Ltd., trade name “ESMENT SUPER 60P”, brain value 6000 cm ² / g, specific gravity 2.91, CaO 49%, Al ₂ O ₃ 16%, SiO ₂ 35%
Ore powder: iron ore powder, hematite ore, specific gravity 4.95, 3 mm under sieve water: tap water

<Curing method>
Normal temperature normal pressure curing: After producing pellets, they were put in a plastic bag, sealed with a mouth tied with a rubber band, and cured for 14 days in an atmospheric pressure environment at 20 ° C.

<Measurement method>
Cold strength: The prepared pellets were sealed and cured in a room temperature environment at 20 ° C., and the compressive strength at the age of 14 days was measured.
Hot strength: The prepared pellets were sealed and cured in a room temperature environment at 20 ° C., fired at a temperature rising rate of 10 ° C./min and a maximum temperature of 900 ° C. in a nitrogen atmosphere at the age of 14 days, and after reaching the maximum temperature, After confirming that the temperature in the furnace reached 20 ° C., the furnace was taken out of the furnace, allowed to cool in a room temperature environment at 20 ° C. for 3 hours, and then measured for compressive strength.
Hot rotational strength (abrasion resistance): A solidified material is prepared by blending Portland cement and pozzolanic reactive substances shown in Table 1. 13 parts of the prepared solidifying material was mixed with 100 parts of the ore powder, and 15 parts of water was mixed with 100 parts of the total of the ore powder and the prepared solidifying material to prepare a kneaded product. For the kneaded material, pellets are produced using a pan-type pelletizer, and the pellets having a diameter in the range of 15 to 11 mm are collected through a sieve. The recovered pellets are sealed and cured in a room temperature environment at 20 ° C., fired at a temperature rising rate of 10 ° C./min and a maximum temperature of 900 ° C. in a nitrogen atmosphere at the age of 14 days, and after reaching the maximum temperature, the furnace After confirming that the internal temperature has reached 20 ° C., it is taken out of the furnace. Pellets m ₀ (parts) after firing were put into a rotating drum having an inner diameter of 130 mm and a length of 200 mm in accordance with JIS M 8720-2001 “Iron ore-low temperature reduced powdering test method”, and rotated at 30 ± 1 rotation / min. Rotate at a total speed of 900 times. After rotation, the pellets were collected, the mass m ₁ (parts) remaining on the 2.8 mm sieve was measured, and the reduced powdering index (%) defined by the following formula was obtained. Reduced powder index (%) = 100−m ₁ / m ₀ × 100

  From the results in Table 1, it can be seen that the pellets using the solidified material are excellent in hot strength. Moreover, when blast furnace granulated slag is contained in this solidification material, it turns out that a reduction | restoration powdering index is high and it is inferior to abrasion resistance. That is, it turns out that this solidification material improves the cold strength, hot strength, and abrasion resistance of a pellet by mix | blending Portland cement and a pozzolanic reactive substance appropriately.

"Experimental example 2"
It carried out similarly to Experimental example 1 except having mix | blended the Portland cement, the pozzolanic reactive substance, and alkanolamine which are shown in Table 2. The results are also shown in Table 2.

<Materials used>
Alkanolamine a: Triethanolamine, manufactured by Kanto Chemical Co., Inc., reagent grade

  From the results in Table 2, it can be seen that the solidified material improves the cold strength, hot strength and wear resistance of the pellets by appropriately blending alkanolamine.

"Experiment 3"
It carried out similarly to Experimental example 1 except having mix | blended the Portland cement, the pozzolanic reactive substance, and alkanolamine which are shown in Table 3. The results are also shown in Table 2.

<Materials used>
Pozzolanic reactive substance Lee -b: classifying sieved pozzolanic reactive substance Lee, which was adjusted to Blaine value 2500 cm ² / g. Specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%
Pozzolanic reactive substance i-c: Pozzolanic reactive substance I was sieved and classified to a brain value of 3000 cm ² / g. Specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%
Pozzolana-reactive substance i-d: A substance obtained by pulverizing pozzolanic-reactive substance i to a brain value of 4300 cm ² / g using a vibration type ball mill. Specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%
Pozzolana-reactive substance i-e: A substance obtained by pulverizing pozzolanic-reactive substance i to a brain value of 5900 cm ² / g using a vibration type ball mill. Specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%
Pozzolana-reactive substance I-f: A substance obtained by pulverizing pozzolanic-reactive substance I to a brain value of 7100 cm ² / g using a vibrating ball mill. Specific gravity 2.35, CaO 6%, Al ₂ O ₃ 27%, SiO ₂ 67%

  From the results in Table 3, it can be seen that the solidified material improves the cold strength and hot strength development and wear resistance of the pellets by increasing the specific surface area of the pozzolanic reactive substance.

"Experimental example 4"
It carried out like Experimental example 1 except having used Portland cement, a pozzolanic reactive substance, and an alkanolamine shown in Table 4. The results are also shown in Table 4.

<Materials used>
Portland cement C: medium heat Portland cement, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “DENKA medium heat Portland cement”, brain value 3050 cm ² / g, specific gravity 3.20, CaO 70%, Al ₂ O ₃ 4%, SiO ₂ 26%
Portland cement D: Low heat Portland cement, Taiheiyo Cement, 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%
Portland cement E: Eco cement, manufactured by Taiheiyo Cement Co., Ltd., trade name “Eco cement”, brain value 4100 cm ² / g, specific gravity 3.18, CaO 71%, Al ₂ O ₃ 9%, SiO ₂ 20%
Portland cement F: fly ash cement, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denka fly ash cement (type B)”, brain value 3500 cm ² / g, specific gravity 2.96, CaO 71%, Al ₂ O ₃ 5%, SiO ₂ 24%

  From the results of Table 4, it can be seen that the present solidified material improves the cold strength, hot strength and wear resistance of the pellets regardless of the type of Portland cement.

“Experimental Example 5”
It carried out similarly to Experimental example 1 except having used the Portland cement, the pozzolanic reactive substance, and the alkanolamine which are shown in Table 5. The results are also shown in Table 5.

<Materials used>
Pozzolanic reactive substance B: silica fume, Chinese, Blaine 22000cm ² / g, specific _{gravity, CaO 0%, Al 2 O} 3 1%, SiO 2 99%
Pozzolanic reactive substance C: Coal ash, coal-fired power plant production, brane value 4400 cm ² / g, specific gravity 2.39, CaO 7%, Al ₂ O ₃ 18%, SiO ₂ 60%

  From the results of Table 5, it can be seen that the solidified material improves the cold strength, hot strength and wear resistance of the pellets regardless of the type of pozzolanic reactive substance.

"Experimental example 6"
It carried out similarly to Experimental example 1 except having used Portland cement, a pozzolanic reactive substance, and an alkanolamine shown in Table 6. The results are also shown in Table 6.

<Materials used>
Alkanolamine b: Triisopropanolamine, manufactured by Kanto Chemical Co., Inc., reagent special grade alkanolamine c: Ethanolamine, manufactured by Kanto Chemical Co., Ltd., reagent special grade alkanolamine d: Diethanolamine, manufactured by Kanto Chemical Co., Ltd., reagent special grade alkanolamine e: N-methyldiethanolamine Manufactured by Wako Chemical Co., Ltd., reagent alkanolamine f: N, N-dimethylethanolamine, manufactured by Wako Chemical Co., Ltd., reagent alkanolamine g: N, N-di-n-butylethanolamine, manufactured by Wako Chemical Co., Ltd., reagent alkanolamine h : N-aminoethylethanolamine, manufactured by Wako Chemical Co., Ltd.

  From the results of Table 6, it can be seen that the solidified material improves the cold strength, hot strength and wear resistance of the pellets regardless of the type of alkanolamine.

"Experimental example 7"
Experiments were conducted except that the solidified material was prepared using Portland cement, 20 parts of pozzolanic reactive substance a-a, and 1 part of alkanolamine, and the amount of water reducing agent added (in terms of aqueous solution and solid content) was changed. Performed as in Example 1. The strength measurement results are shown in Table 7.

<Materials used>
Water reducing agent: commercial product (copolymer of polyalkenyl ether and maleic anhydride), 60% aqueous solution

  From the results of Table 7, it can be seen that when the water reducing agent is added, the solidified material improves the cold strength, hot strength and wear resistance of the pellet in proportion to the addition rate.

"Experimental example 8"
Experimental Example 1 except that 80 parts of Portland cement A, 20 parts of pozzolanic reactive substance I-a, and 1 part of alkanolamine were used to prepare a solidified material, and 100 parts of iron ore powder were mixed in the amounts shown in Table 8. As well as. The results are also shown in Table 8.

  From the results of Table 8, it can be seen that excellent cold strength, hot strength, and wear resistance of the pellet can be obtained by blending the solidified material with an appropriate amount of ore powder.

"Experimental example 9"
80 parts of Portland cement A, 20 parts of pozzolanic reactive substance i-a, and 1 part of alkanolamine are used to prepare a solidified material. To 100 parts of iron ore powder, 13 parts of the prepared solidified material are mixed to prepare iron ore powder. The test was performed in the same manner as in Experimental Example 1 except that water shown in Table 8 was blended in a mass ratio with respect to the total solidified material. The results are also shown in Table 9.

  From the results of Table 9, excellent cold strength, hot strength, and wear resistance of pellets can be obtained by adjusting the water / (ore powder + solidified material) ratio of the solidified material to an appropriate range. I understand.

"Experimental example 10"
A solidified material was prepared using 80 parts of Portland cement A, 20 parts of pozzolanic reactive substance i, and 1 part of alkanolamine, and 13 parts of the prepared solidified material was mixed with 100 parts of iron ore powder to prepare iron ore. A total of 100 parts of the solidified material was mixed with 15 parts of water to prepare pellets.
The same procedure as in Experimental Example 1 was performed except that the curing method after pelletizing the prepared pellets was changed as shown in Table 10. The results are also shown in Table 10.

<Curing method>
Steam curing: After pelletizing the pellets, the pellets were placed for 2 hours in advance, and then steam cured under conditions of a temperature increase of 15 ° C./min and a maximum temperature of 70 ° C. for 3 hours. The next day, it was removed from the curing tank and cured in a 20 ° C. environment for 13 days.
Autoclave curing: After pelletizing pellets, the pellets were put into a pressure kiln and cured for 6 hours in an environment of a vapor pressure of 10 atm and a temperature of 170 ° C. After curing, curing was performed for up to 14 days in a room temperature environment of 20 ° C.
Wet air curing: After pelletizing the pellets, the pellets were cured for 14 days in a room temperature environment of 100% humidity and 20 ° C.
Heat curing: After pelletizing the pellets, the pellets were sealed and cured at 20 ° C. in a room temperature environment for 1 day, and then cured in a dryer at 40 ° C. for 13 days.

  From the results of Table 10, it can be seen that the present solidified material improves the cold strength and hot strength of the pellets and the wear resistance regardless of the curing method.

  According to the ore powder hot solidified material according to the present invention, the pellets using the same and the manufacturing method thereof, the cold strength is equal to or higher than that of the conventional solidified material, and the hot strength is excellent. Therefore, it can be suitably used for pelletizing dust collection dust generated in ironworks, steelworks, non-ferrous smelters and the like.

Claims (15)

A hot-strength enhanced solidified material of ore powder that contains 70 to 90 parts by mass of Portland cement and 10 to 30 parts by mass of a pozzolanic reactive substance and does not contain slag. The hot-strength enhanced solidified material according to claim 1, wherein the pozzolanic reactive material is fly ash. Pozzolanic reactive hot strength enhancement solidifying material according to claim 1 or claim 2 having a specific surface area of the 2500 cm 2 / ^g or more substances. The hot-strength enhanced solidified material according to any one of claims 1 to 3, wherein the Portland cement is an early-strength Portland cement. The hot-strength enhanced solidified material according to any one of claims 1 to 4, comprising an alkanolamine. The hot strength enhanced solidified material according to claim 6, wherein the content of alkanolamine is 0.1 to 20 parts by mass with respect to 100 parts by mass of the pozzolanic reactive substance. The hot strength enhanced solidified material for ore powder according to any one of claims 1 to 6, comprising a water reducing agent. The hot strength-enhancing solidified material of ore powder according to claim 7, wherein the water reducing agent is 0.5 to 8 parts by mass in solid content with respect to 100 parts by mass of the solidified material. The water reducing agent is R1O (A1O) mR2 [wherein A1O is one or a mixture of two or more oxyalkylene groups having 2 to 3 carbon atoms, and when it is two or more, it may be added in a block shape randomly. R1 is an alkenyl group having 2 to 5 carbon atoms, R2 is an alkyl group having 1 to 4 carbon atoms, and m is an average addition mole number of oxyalkylene groups of 20 to 150]. Alkenyl ether and Z [O (A2O) nR3] a [wherein Z is a residue of a compound containing a hydroxyl group having 2 to 8 and A2O is one of oxyalkylene groups having 2 to 3 carbon atoms or A mixture of two or more types, and when there are two or more types, they may be added in blocks or randomly, R3 is an alkenyl group having 2 to 5 carbon atoms, and n is an average addition of oxyalkylene groups 0 or 1 or more in moles A number, a is a polyalkenyl ether represented by 2 to 8, ore powder hot strength enhancement solidifying material according to claim 7 or 8 comprising a copolymer of maleic anhydride. A pellet comprising ore powder, a hot strength-enhancing solidifying material of ore powder according to any one of claims 1 to 9, and water. The pellet of Claim 10 whose solidification material is 3-20 mass parts with respect to 100 mass parts of ore powder. The pellet according to claim 10 or 11, wherein a ratio of water / (ore powder + hot-strength solidification material) (mass) is 0.03 to 0.3. A method for producing pellets comprising pelletizing and curing a mixture of ore powder, the hot strength-enhancing solidifying material of ore powder according to any one of claims 1 to 9, and water. The manufacturing method of the pellet of Claim 13 which mixes 3-20 mass parts of solidification materials with respect to 100 mass parts of ore powder. The method for producing pellets according to claim 13 or 14, wherein a ratio of water / (ore powder + solidifying material) (mass) is 0.03 to 0.3.