WO2024257890A1

WO2024257890A1 - Modification method and modification apparatus of raw material

Info

Publication number: WO2024257890A1
Application number: PCT/JP2024/080084
Authority: WO
Inventors: Takashi Kikkawa; Natsumi Taniyama
Original assignee: Kurita Water Industries Ltd
Current assignee: Kurita Water Industries Ltd
Priority date: 2023-06-13
Filing date: 2024-06-11
Publication date: 2024-12-19
Anticipated expiration: 2025-12-13
Also published as: TW202513775A; JP2024178756A

Abstract

A method of modifying a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the modification method including steps of: (1) continuously measuring a moisture percentage of the raw material; (2) continuously measuring an amount of the raw material that is present at a specific position of the conveyance equipment; (3) continuously measuring start and stop of the conveyance equipment; (4) calculating, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material; (5) determining whether or not addition of the modifier is necessary based on the amount of the raw material and the start and stop; (6) calculating, based on the amount of the raw material and the target concentration (A), a target additive amount (B) per unit time of the modifier; and (7) adding the target additive amount (B) to the raw material when addition of the modifier is necessary.

Description

DESCRIPTION

Title of Invention

MODIFICATION METHOD AND MODIFICATION APPARATUS OF RAW MATERIAL

Technical Field

[0001]

The present invention relates to a modification method and a modification apparatus of a raw material and, particularly, a raw material in a wet state.

Background Art [0002]

At ironworks, thermal power plants, and the like, mineral raw materials and fuel (hereinafter, sometimes referred to as raw materials) are usually piled up in the open in a raw material yard as stock. Raw materials piled up in a raw material yard may contain water sprayed as a dust control measure or rainwater and tend to have a high moisture percentage. In addition, while raw materials carried by a bulk carrier or the like are discharged and transported to a raw material yard, raw materials stored under a hatchway during carriage tend to have a high moisture percentage.

Raw materials are usually conveyed by a belt conveyor (hereinafter, BC) upon discharge or conveyance from the raw material yard. Such raw materials with a high moisture percentage cause adhesion, clogging, blocking, and the like during a conveyance process. In addition, coal for a coke oven with a high moisture percentage causes a decline in bulk density in the coke oven. In consideration of the above, a modifier may be used for the purpose of failure prevention. Usually, the modifier is sprayed on the raw material on the BC and the raw material and the modifier are mixed in a transfer part to exert a modifying effect.

[0003]

As a method of adding a modifier, a method is known in which a person determines a conveyance amount or out-of-cargo based on appearance and changes a setting of an amount of chemical injection.

However, the BC does not necessarily constantly convey a raw material and may repetitively start and stop according to operational circumstances and a conveyance amount is also not constant. In particular, during unloading from a bulk carrier, conveyance of the raw material stops during replacing of a hatch, cleaning of a bucket, fixing a meandering BC, and the like. In addition, operations involving unloaders used in discharge may switch between an operation using one unloader and an operation using two unloaders and, what is more, since a capability of each unloader differs, a conveyance amount varies. Since a discharge takes several days, it is difficult to manually control chemical injection by constant monitoring. When chemical injection control is insufficient, chemical injection is to continue in a state where there is no raw material on the BC and, depending on a type of the modifier, a problem may arise where the chemical adheres to the BC and makes it easier for the raw material to adhere to the BC.

Therefore, there is a need to control the chemical injection amount in an automated manner instead of having a person change a setting of the chemical injection amount as described above.

[0004]

PTL1 describes a method of modifying a mineral raw material by adding a modifier to the mineral raw material, the method including steps of: continuously measuring a moisture percentage of the mineral raw material to be conveyed; calculating an additive amount of the modifier based on the moisture percentage; and adding the modifier in the additive amount to the mineral raw material, wherein adding the modifier prevents at least any of adhesion of the mineral raw material to conveyance equipment, clogging of the mineral raw material in the conveyance equipment, ej ection of the mineral raw material inside the conveyance equipment and to outside of the conveyance equipment, and a decline in bulk density of the mineral raw material.

PTL2 describes a chemical solution-adding apparatus which adds a chemical solution to a hydrous bulk material while the hydrous bulk material containing ore and coal is being discharged from a cargo ship onto a belt conveyor using a grab bucket of a bridge crane or an unloader and the hydrous bulk material is being conveyed to a yard by the belt conveyor, wherein the chemical solution-adding apparatus includes: adding means which adds a chemical solution; additive amount control means which controls an additive amount of the chemical solution; a sensor which gathers information for determining start and stop of addition of the chemical solution; a chemical solution tank which stores the chemical solution to be added; and a conveyance hose which conveys the chemical solution from the chemical solution tank to the adding means.

Citation List

Patent Literature [0005]

PTL1: JP 2021-167442 A

PTL2: JP 2015-196573 A

Summary of Invention

Technical Problem

[0006]

In PTL1, a content of the modifier in the raw material is controlled to reach a predetermined concentration regardless of whether a conveyance amount of the raw material on the BC is large or small. However, when the modifier is sprayed so as to reach the predetermined concentration when the conveyance amount is small, an inconvenience may occur in which the modifier adheres to the BC or other equipment, promotes adhesion of the raw material, and causes the raw material to adhere to the BC or causes clogging or the like of the raw material in a transfer chute part.

PTL2 discloses adding a chemical solution when a BC is operational and cargo is present on the BC. However, even in PTL2, when a modifier is sprayed so as to reach a predetermined concentration when an amount of the cargo on the BC is small, an inconvenience may occur in which the modifier adheres to the BC or other equipment, promotes adhesion of a raw material, and causes the raw material to adhere to the BC or causes clogging or the like of the raw material in a transfer chute part.

[0007]

An object of the present invention is to provide a modification method and a modification apparatus of a raw material which can be automated, which is capable of controlling an additive amount of a modifier to a raw material to an appropriate amount, and which is capable of suppressing adhesion of the modifier and the raw material to conveyance equipment (such as a BC).

Solution to Problem

[0008]

The present invention provides [1] to [5] below.

[1] A method of modifying a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the method including steps of:

(1) continuously measuring a moisture percentage of the raw material that is conveyed;

(2) continuously measuring an amount of the raw material that is present at a specific position of the conveyance equipment; (3) continuously measuring start and stop of the conveyance equipment;

(4) calculating, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material;

(5) determining whether or not addition of the modifier is necessary based on the amount of the raw material and the start and stop;

(6) calculating, based on the amount of the raw material and the target concentration (A), a target additive amount (B) per unit time of the modifier; and

(7) adding the target additive amount (B) to the raw material when addition of the modifier is necessary but not adding the target additive amount (B) to the raw material when addition of the modifier is not necessary, wherein the modification method of a raw material prevents at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, meandering and biasing of the conveyance equipment, and a decline in bulk density of the raw material.

[2] The modification method of a raw material according to [1] described above, wherein the conveyance equipment is at least one of piping, a belt conveyor, a conveyor chain, a chute, a hopper, a silo, and a coke oven.

[3] A modification apparatus which modifies a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the modification apparatus including: a moisture percentage measurement apparatus which continuously measures a moisture percentage of the raw material that is conveyed; a raw material measurement apparatus which continuously measures an amount of the raw material that is present at a specific position of the conveyance equipment; a start/stop measurement apparatus which continuously measures start and stop of the conveyance equipment; a control apparatus which calculates, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material; a control apparatus which determines whether or not addition of the modifier is necessary based on the amount of the raw material and the start and stop; a control apparatus which calculates, based on the amount of the raw material and the target concentration, a target additive amount (B) per unit time of the modifier; and a modifier adding apparatus which adds the target additive amount (B) to the raw material when addition of the modifier is necessary but which does not add the target additive amount (B) to the raw material when addition of the modifier is not necessary, wherein the modification apparatus of a raw material prevents at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, meandering and biasing of the conveyance equipment, and a decline in bulk density of the raw material.

[4] The modification apparatus of a raw material according to [3] described above, wherein the start/stop measurement apparatus is a start/stop binary apparatus which measures whether the conveyance equipment has started or stopped and which does not measure a movement speed.

[5] The modification apparatus of a raw material according to [3] described above, wherein the start/stop measurement apparatus is a movement speed measurement apparatus of the conveyance equipment.

Advantageous Effects of Invention

[0009]

The modification method and the modification apparatus of a raw material according to the present invention can be automated and are capable of controlling an additive amount of a modifier to a raw material to an appropriate amount and suppressing adhesion of the modifier and the raw material to conveyance equipment (such as a BC).

Brief Description of Drawing

[0010]

[Fig. 1] Fig. 1 is a schematic view for explaining a modification method and a modification apparatus of a raw material according to the present invention.

Description of Embodiments

[0011]

Hereinafter, a modification method of a raw material according to the present invention will be described.

Note that the expression "preventing adhesion of the raw material to conveyance equipment" according to the present invention is used to mean not only a case where there is no adhesion whatsoever but to also include cases where even if partial adhesion occurs, the adhesion is suppressed enough to prevent conveyance of the raw material from being interrupted.

In the present invention, the expression "continuously measure" means continuously performing measurements instead of performing just one measurement and, for example, refers to a case where a measurement of an amount of the conveyed raw material or a moisture percentage of the conveyed raw material is performed a plurality of times at specific intervals.

[0012]

[Modification method of raw material]

The modification method of a raw material according to the present invention is a method of modifying the raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the method including steps of:

(2) continuously measuring an amount of the raw material that is present at a specific position of the conveyance equipment;

(3) continuously measuring start and stop of the conveyance equipment;

The modification method of a raw material according to the present invention can be automated and is capable of controlling an additive amount of a modifier to a raw material to an appropriate amount and suppressing adhesion of the modifier and the raw material to conveyance equipment (such as a BC).

[0013] <Raw material>

In the present invention, a raw material means a mineral raw material or a mineral fuel.

Types of the raw material are not particularly limited and examples include coal, iron ore, metal ore other than iron ore, dust, slag, sludge, coke, sintered ore, and limestone. One of these raw materials may be used independently or a mixture of two or more of these raw materials may be used.

In addition, while a shape, a size, and the like of the raw material are not particularly limited, from the perspective of preventing clogging, a form that is less likely to clog such as a granulated shape with a particle size of one particle ranging from 0.1 |lm to 10 mm is suitably applied.

[0014]

In the present invention, the "raw material" to be an object of adding a modifier is a wet raw material containing moisture. A "wet raw material" refers to a raw material which is in a humid state and which can be conveyed by a belt conveyor. While the moisture percentage of wet raw materials cannot be categorically set due to different types and shapes of raw materials, for example, in a case of coal with a particle size ranging from 0.1 gm to 10 mm, the moisture percentage is more than 9 percent by mass and preferably 11 percent by mass or more. In addition, for example, in a case of iron ore with a particle size ranging from 0.1 m to 10 mm, the moisture percentage is more than 7 percent by mass and preferably 9 percent by mass or more.

An origin of the moisture in the raw material is not particularly limited and the moisture may derive from the raw material itself or derive from rain that the raw material had come into contact with during conveyance or storage or from water sprayed as means of dust prevention.

[0015]

The modifier is not particularly limited and examples include organic substances such as a super absorbent resin, a water-soluble polymer compound, a surfactant, and an organic solvent and inorganic substances such as dust and slag created at ironworks, coal, coke, iron ore, diatomaceous earth, and ceramics. One of these substances may be used independently or each of two or more of these substances may be used independently, or a mixture of two or more of these substances may be used.

From the perspective of preventing adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, and ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment, the modifier preferably contains at least one substance selected from the group consisting of super absorbent resins and water-soluble polymer compounds and more preferably contains a super absorbent resin.

In addition, from the perspective of improving bulk density of the raw material, the modifier preferably contains a surfactant.

[0016]

(Super absorbent resin)

A super absorbent resin according to the present invention is a resin defined in JIS K7223 (1996) and JIS K7224 (1996) as "a resin which absorbs a large amount of water and swells and which is a hydrophilic substance with a cross-linked structure that absorbs water by coming into contact with the water and, once having absorbed water, hardly loses the water even under pressure". In other words, a super absorbent resin absorbs a large amount of water and has superior water retention ability.

When the super absorbent resin described above is added to and mixed with a wet raw material, the super absorbent resin absorbs at least a part of the moisture in the raw material. Accordingly, since a moisture percentage of a surface of the raw material decreases, slidability of the raw material increases on a contact surface of the conveyance equipment, and the raw material becomes less likely to adhere to the contact surface, adhesion of the raw material to the conveyance equipment, clogging of the raw material in the conveyance equipment, ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment, and the like can be prevented. Note that adherence of the raw material with respect to the contact surface of the conveyance equipment need only be suppressed and an entire amount of moisture in the raw material need not be absorbed by the super absorbent resin.

[0017]

While a type of the super absorbent resin may be either a synthetic resin-based type or a nature-derived type and is not particularly limited, examples of the super absorbent resin include poly(meth)acrylic acid, a poly(meth)acrylate salt, a poly(meth)acrylic acid ester, poly(meth)acrylamide, polyalkyleneimine, polyoxyalkylene, polymaleic acid, and a copolymer or the like containing any of the monomers constituting these super absorbent resins. Note that in the present invention, "(meth)acrylic" means acrylic or methacrylic. [0018]

Examples of a monomer that constitutes the poly(meth)acrylate salt include sodium (meth)acrylate, potassium (meth)acrylate, and ammonium (meth)acrylate. Examples of a monomer that constitutes the poly(meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hydroxyethyl (meth)acrylate, and 2-ethylhexyl (meth) acrylate.

Examples of a monomer that constitutes polyalkyleneimine include ethyleneimine and methylethyleneimine .

Examples of a monomer that constitutes polyoxyalkylene include ethylene oxide and propylene oxide.

Examples of other monomers that constitute the copolymers include vinyl sulfonic acid, styrenesulfonic acid, N-ethyl(meth)acrylamide, and vinylpyridine.

[0019]

One of these super absorbent resins may be used independently or two or more of these super absorbent resins may be used in combination. From the perspectives of availability, high water absorption power, and the like, polyacrylic acid or sodium polyacrylate is suitably used and sodium polyacrylate is particularly preferable.

In addition, the super absorbent resin may be used in combination with an additional water-absorbing agent. Examples of the additional water-absorbing agent include silica gel, zeolite, and activated carbon.

As properties of the super absorbent resin, from the perspective of uniformly mixing with raw material and the perspective of handleability or the like, the super absorbent resin has a granulated or powder form with a particle size equivalent or smaller than the particle size of the raw material. For example, in a case of coal with a particle size ranging from 0.1 m to 2 mm, a super absorbent resin with a particle size preferably ranging from 10 to 1000 pm and more preferably ranging from 50 to 600 pm is used. In addition, a liquid super absorbent resin dispersed in an organic solvent may be used or a liquid super absorbent resin may be used. Although the organic solvent is not particularly limited, a high-boiling point solvent such as an aromatic organic solvent is preferably used.

[0020]

From the perspective of efficiently conveying the raw material, a content of the super absorbent resin in active substances of the modifier (components of the modifier excluding a solvent) preferably ranges from 5 to 100 percent by mass, more preferably ranges from 50 to 100 percent by mass, and even more preferably ranges from 90 to 100 percent by mass. [0021] (Water-soluble polymer compound) A water-soluble polymer compound according to the present invention absorbs a large amount of water and has superior water retention ability. In the present invention, being water-soluble refers to dissolution of 0.01 g or more in 100 g of water at 25°C.

When the water-soluble polymer compound is added to and mixed with a wet raw material, the water-soluble polymer compound absorbs at least a part of the moisture in the raw material. Accordingly, since a moisture percentage of a surface of the raw material decreases, slidability of the raw material increases on a contact surface of the conveyance equipment, and the raw material becomes less likely to adhere to the contact surface, adhesion of the raw material to the conveyance equipment, clogging of the raw material in the conveyance equipment, ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment, and the like can be prevented. Note that adherence of the raw material with respect to the contact surface of the conveyance equipment need only be suppressed and an entire amount of moisture in the raw material need not be absorbed by the water-soluble polymer compound.

The water-soluble polymer compound may be an artificially-produced synthetic high polymer compound or a naturally-present natural high polymer compound and examples of the water-soluble polymer compound include a synthetic water-soluble polymer compound, semisynthetic water-soluble polymer compound, and a natural water-soluble polymer compound.

[0022]

Examples of the synthetic water-soluble polymer compound include polyvinyl alcohol, polyvinylpyrrolidone, or a salt thereof, polyethylene oxide, polyvinyl methyl ether; a copolymer of (meth)acrylic acid, (meth)acrylamide, maleic anhydride, maleic acid, maleic acid amide, maleic acid imide, itaconic acid, crotonic acid, or fumaric acid or a salt thereof, and the like. Examples of the salt thereof include salts with alkaline metals such as sodium and potassium.

[0023]

Examples of the semisynthetic water-soluble polymer compound include a cellulose derivative such as viscose, methylcellulose, cationized cellulose, ethylcellulose, carboxymethylcellulose, and hydroxypropylcellulose; a starch derivative such as pregelatinized starch, carboxyl starch, dialdehyde starch, cationic starch, dextrin, and British gum; cationized guar gum, anionized guar gum, and methylglycol chitosan.

[0024] Examples of the natural water-soluble polymer compound include starch, mannan, guar gum, xanthan gum, sodium alginate, locust bean gum, pectin, dextran, gelatin, rhamsan gum, and gellan gum. [0025]

The water-soluble polymer compound may be any of anionic, cationic, nonionic, and amphoteric. Among these properties, anionic and nonionic with reduced toxicity to fish are preferable and anionic is further preferable. [0026]

The water-soluble polymer compound is preferably a synthetic water-soluble polymer compound. As the synthetic water-soluble polymer compound, a homopolymer or a copolymer containing one or two or more anionic monomers and nonionic monomers as constituents is suitable. Examples of an anionic group (the anionic monomer) include a carboxylic acid (monomer) such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid; a sulfonic acid (monomer) such as styrenesulfonic acid, vinylsulfonic acid, and 3-allyloxy-2-hydroxypropanesulfonic acid, and the like. In addition, examples of a nonionic group (the nonionic monomer) include acrylamide (monomer) and methacrylamide (monomer). As the synthetic water-soluble polymer compound, an acrylic acid-based and/or acrylamide-based polymer is further preferable. Examples of the acrylic acid-based and/or acrylamide-based polymer include an acrylic acid homopolymer, an acrylamide homopolymer, an acrylic acid/acrylamide copolymer, a partial hydrolysate of polyacrylamide, acrylic acid/acrylamide/2-acrylamide-2-methylpropanesulfonic acid, acrylic acid/maleic acid copolymer or a salt thereof, and the like and one of these substances may be used independently or two or more of these substances may be used in combination. Among these substances, an acrylic acid/acrylamide copolymer, an acrylamide homopolymer, and a partial hydrolysate of polyacrylamide are all high molecular-weight and can be suitably used in the applications according to the present invention.

A weight average molecular weight of the acrylamide-based or acrylic acid-based polymer preferably ranges from 1,000,000 to 10,000,000 and more preferably ranges from 5,000,000 to 9,000,000 (intrinsic viscosity method).

In addition, in the case of an anionic polymer, a content in units of acrylic acid when producing the acrylic acid-based and/or acrylamide-based polymer is preferably 5 mol percent or higher and more preferably ranges from 20 to 100 mol percent with respect to a total amount (100 mol percent) of the used monomers.

A state when using the water-soluble polymer compound is not particularly limited and the water-soluble polymer compound is suitably used in a powder form, a liquid form, or an emulsion form. In particular, the water-soluble polymer compound is suitably used in a powder form or an emulsion form which enables the water-soluble polymer compound to be used without adding moisture to an object to be conveyed. A water-soluble polymer compound in the form of a water/oil emulsion can be manufactured by known methods (for example, JP S52-039417 B and JP S51-41090 A).

[0027]

One of the water-soluble polymer compounds may be used independently or two or more of the water-soluble polymer compounds may be used in combination. An acrylic acid/acrylamide copolymer, an acrylamide homopolymer, and a partial hydrolysate of polyacrylamide are all high molecular-weight and can also be suitably used from the perspective of efficiently conveying the raw material.

[0028]

From the perspective of efficiently conveying the raw material, a content of the water- soluble polymer compound in active substances of the modifier preferably ranges from 5 to 80 percent by mass, more preferably ranges from 20 to 60 percent by mass, and even more preferably ranges from 30 to 50 percent by mass.

[0029]

(Surfactant)

As the surfactant, for example, an anionic surfactant such as a dialkyl sulfosuccinic acid (suitably with an alkyl group having 8 to 16 carbons) or a salt thereof (for example, a sodium salt, an ammonium salt, a potassium salt, or a triethanolamine salt), a polyoxyethylene alkyl ether sulfate salt, or sodium alkane sulfonate, a nonionic surfactant such as a polyoxyethylene (POE) addition polymer or a salt thereof, and the like can be used.

When the surfactant is added to and mixed with a wet raw material, slidability of the raw material improves and bulk density of the raw material increases. Due to the improved bulk density, a contribution can be made toward improving productivity of industrial products using the raw material.

One of these surfactants may be used independently or two or more of these surfactants may be used in combination. From the perspective of improving the bulk density of the raw material, an anionic surfactant is preferable and sodium alkane sulfonate is more preferable.

[0030]

From the perspective of improving bulk density, a content of the surfactant in active substances of the modifier preferably ranges from 5 to 100 percent by mass, more preferably ranges from 10 to 50 percent by mass, and even more preferably ranges from 20 to 30 percent by mass.

[0031]

<Conveyance equipments

Conveyance equipment according to the present invention refers to, for example, conveyance equipment in a conveyance line that feeds a raw material along a predetermined line from a storage location of the raw material such as a raw material yard to a facility where the raw material is to be used and includes functions for temporarily storing the raw material such as a chute, a hopper, and a silo. The conveyance equipment according to the present invention refers to equipment for conveying raw material in a conveyance facility and is to be distinguished from carriage by a ship, a truck, or the like and from conveyance by a bucket or the like.

In the present invention, an effect of preventing adhesion of the raw material, clogging of the raw material, and ejection of the raw material in the conveyance equipment and to outside of the conveyance equipment can be produced at locations in the conveyance equipment where an inconvenience due to adhesion and clogging readily occurs such as piping, a belt conveyor, a conveyor chain, a chute, a hopper, a silo, and a coke oven.

A wet raw material is susceptible to problems such as adhesion, clogging, and ejection in such conveyance equipment and when a problem occurs, the problem must be solved after stopping an operation of a line which is time- and labor-consuming.

By comparison, in the present invention, when an additive amount of a modifier is calculated and the modifier is added in the additive amount to a raw material according to the method described below, slidability of the raw material on a contact surface of the conveyance equipment improves and, since adhesion, clogging, and ejection of the raw material are prevented, the raw material can be efficiently conveyed without having to stop the operation of the line.

[0032]

Step (1) is a step of continuously measuring a moisture percentage of the raw material that is conveyed.

While an interval of measuring the moisture percentage is not particularly limited and differs according to a type, properties, a conveyance amount, and the like of the raw material, when coal is used as the raw material and the conveyance amount ranges from 1 to 20 t/minute, the moisture percentage is preferably measured once every 0.1 to 60 seconds. While an interval of measuring the conveyance amount is not particularly limited and differs according to a type, properties, a conveyance speed, and the like of the raw material, when coal is used as the raw material and the moisture percentage the coal ranges from 5 to 25 percent by mass, the conveyance amount is preferably measured once every 0.1 seconds to 1 minute.

[0033]

As a method of measuring the moisture percentage of the raw material, a measurement using a non-contact moisture meter is preferable from the perspective of continuous measurement. Examples of the non-contact moisture meter include an infrared moisture meter, a microwave moisture meter, a neutron moisture meter, an electrical resistance moisture meter, and a capacitance moisture meter.

Among these methods, measurement using an infrared moisture meter which involves irradiating the raw material with infrared light and measuring intensity of reflected light is preferable from the perspectives of easy installation and ease of use. For example, CM710e manufactured by NDC Technologies and the like can be adopted.

A period of time required to measure the moisture percentage of the raw material preferably ranges from 0.1 to 60 seconds and more preferably ranges from 1 to 10 seconds from the perspectives of productivity and adding the modifier in an appropriate additive amount corresponding to the moisture percentage of the raw material.

[0034]

Step (2) is a step of continuously measuring an amount of the raw material that is present at a specific position of the conveyance equipment.

Examples of a method of measuring an amount of the raw material include load measurement apparatuses such as a load-cell load measurement apparatus and a Merrick load measurement apparatus and distance measurement apparatuses such as an optical distance measurement apparatus, a millimeter-wave distance measurement apparatus, and an ultrasonic distance measurement apparatus.

With a load measurement apparatus, an amount of the raw material is calculated based on a mass value of the raw material on the belt conveyor and a movement speed of the belt conveyor. In addition, with a distance measurement apparatus, a distance sensor is installed in an upper part of the belt conveyor, and an amount of the raw material is calculated based on a difference between a distance from the distance sensor to a bottom part of the belt conveyor and a distance between the distance sensor and the raw material on the belt conveyor. A period of time required to measure the amount of the raw material preferably ranges from 0.1 to 60 seconds and more preferably ranges from 1 to 10 seconds from the perspectives of productivity and adding the modifier in an appropriate additive amount corresponding to the moisture percentage of the raw material.

[0035]

A position where the moisture percentage of the conveyed raw material and the amount of the raw material are measured is preferably installed on an upstream side of a position where the modifier is added and in a vicinity of the conveyance equipment such as a belt conveyor which conveys the raw material that is a measurement object. hr an aspect of the present invention, when measuring the moisture percentage and an amount of the raw material, the measurement of the moisture percentage may be performed before the measurement of the conveyance amount, the measurement of the amount of the raw material may be performed before the measurement of the moisture percentage, or the measurements of the moisture percentage and the amount of the raw material may be performed concurrently. When the raw material is not being conveyed, since there is no need to measure the moisture percentage, the measurement of the amount of the raw material is preferably performed before the measurement of the moisture percentage.

[0036]

Step (3) is a step of continuously measuring start and stop of the conveyance equipment.

Examples of a method of measuring start and stop include a Merrick belt scale, a roller encoder, a belt conveyor operation motor, and current measurement using a vibration sensor or a sound sensor.

[0037]

Step (4) is a step of calculating, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material.

While the target concentration (A) of the modifier differs according to a type, properties, and the like of the raw material, for example, when the raw material is coal, since a moisture percentage of coal of less than approximately 7 percent by mass hardly causes adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, and ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment and also attains relatively high bulk density, the target concentration (A) of the modifier is calculated as 0 percent by mass. In other words, excessive addition of the modifier is suppressed.

When the moisture percentage of coal is approximately 7 percent by mass or more, the modifier needs to be added. The target concentration (A) of the modifier can be calculated based on a reference value that is a suitable concentration of the modifier with respect to the moisture percentage of the raw material obtained in advance by a simulation or a calibration curve and on a measurement result of the moisture percentage of coal. The higher the moisture percentage of coal, the higher the target concentration (A) of the modifier.

[0038]

By calculating the target concentration (A) of the modifier based on a measurement result of the moisture percentage of the raw material and adding the modifier so as to attain the calculated target concentration (A) of the modifier in step (7) to be described later, a situation where a modification effect is insufficient due to a deficit of the modifier can be prevented.

In addition, since the target concentration (A) of the modifier is calculated based on a measurement result of the moisture percentage of the raw material in the present invention, the addition of the modifier can be prevented from becoming excessive and a modifier cost can be reduced. Furthermore, when the reference value that is a suitable concentration of the modifier with respect to the moisture percentage of the raw material obtained in advance by a simulation or a calibration curve and the measurement result of the moisture percentage of the raw material significantly differ from each other, a determination that the raw material is not present on a belt conveyor can be made and the addition of the modifier can be stopped. [0039]

While the target concentration (A) of the modifier differs according to a type and characteristics of the raw material and is calculated based on the moisture percentage of the raw material or based on the moisture percentage and the conveyance amount of the raw material, when the raw material is coal with a particle size ranging from 0.1 pm to 2 mm and a moisture percentage of 9 percent by mass or more and the modifier contains a super absorbent resin, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.01 to 0.5 percent by mass. In addition, when the raw material is coal with a particle size ranging from 0.1 pm to 2 mm and a moisture percentage of 9 percent by mass or more and the modifier contains a water-soluble polymer compound, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.01 to 0.5 percent by mass. By adopting the ranges described above, at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, and ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment can be prevented.

When the raw material is coal with a particle size ranging from 0.1 gm to 2 mm and a moisture percentage of 9 percent by mass or more and the modifier contains a surfactant, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.05 to 0.5 percent by mass. By adopting the ranges described above, a decline in bulk density of the raw material can be prevented. [0040]

When the raw material is iron ore with a particle size ranging from 0.1 pm to 2 mm and a moisture percentage of 7 percent by mass or more and the modifier contains a super absorbent resin, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.01 to 0.5 percent by mass. In addition, when the raw material is iron ore with a particle size ranging from 0.1 pm to 2 mm and a moisture percentage of 7 percent by mass or more and the modifier contains a water-soluble polymer compound, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.01 to 0.5 percent by mass. By adopting the ranges described above, at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, and ejection of the raw material inside the conveyance equipment and to outside of the conveyance equipment can be prevented.

In addition, when the raw material is iron ore with a particle size ranging from 0.1 pm to 2 mm and a moisture percentage of 7 percent by mass or more and the modifier contains a surfactant, the target concentration (A) of the modifier preferably ranges from 0.001 to 50 percent by mass, more preferably ranges from 0.005 to 5 percent by mass, and even more preferably ranges from 0.05 to 0.5 percent by mass. By adopting the ranges described above, a decline in bulk density of the raw material can be prevented.

[0041]

Step (5) is a step of determining whether or not addition of the modifier is necessary based on the start and stop and an amount of the raw material.

For example, in step (5), the following determinations are made. - (a) Start/stop is start and amount of the raw material is a predetermined amount or more: added.

- (b) Start/stop is start and amount of the raw material is less than the predetermined amount: not added.

- (c) Start/stop is stop and amount of the raw material is the predetermined amount or more: not added.

- (d) Start/stop is stop and amount of the raw material is less than the predetermined amount: not added.

As described in (a) above, by adding the modifier when start/stop is start and the amount of the raw material that is present at a specific position of the conveyance equipment is a predetermined amount or more, adhesion of the modifier and the raw material to the conveyance equipment (such as a BC) can be suppressed.

In addition, as described in (b) above, when the amount of the raw material that is present at a specific position of the conveyance equipment is less than the predetermined amount even though start/stop is start, adhesion of the modifier and the raw material to the conveyance equipment (such as a BC) can be suppressed without adding the modifier. In addition, inadvertently adding the modifier when the amount of the raw material that is present at a specific position of the conveyance equipment is less than the predetermined amount may cause an inconvenience in which the modifier adheres to a conveyance apparatus such as a belt conveyor, promotes adhesion of the raw material, and causes the raw material to adhere to the BC or causes clogging or the like of the raw material in a transfer chute part. Specifically, while a chemical injection of the modifier is performed either at several points or continuously with respect to a width direction of the belt conveyor since the chemical injection of the modifier is desirably performed so that the modifier becomes uniform with respect to the raw material, a width of the raw material is narrow and causes the modifier to be directly added onto the BC when the conveyance amount is less than the predetermined amount. By comparison, since the modifier is not added in the case of (b) described above, the inconvenience can be avoided and an amount of use of the modifier can be suppressed.

As described in (c) and (d) above, by not adding the modifier when start/stop is stop, a situation where the modifier is added to the raw material a plurality of times during the stop and the modifier adheres to the conveyance equipment can be prevented and an amount of use of the modifier can be suppressed.

[0042]

<Step (6)> Step (6) is a step of calculating, based on the amount of the raw material and the target concentration (A) of the modifier, a target additive amount (B) per unit time of the modifier.

Accordingly, the modifier can be added to the raw material without an excess or a deficiency.

For example, the target additive amount (B) (ton/hr) per unit time of the modifier can be calculated using the following equation.

- Target additive amount (B) = X/Y x Z x A

In the equation, the meanings of the respective symbols are as follows.

- X: amount of the raw material that is present at a specific position of the conveyance equipment (ton)

- Y: length in the conveying direction of the specific position (m)

- Z: conveyance speed (m/hr)

- A: target concentration (A) of the modifier (percent by mass)

When a conveyance apparatus such as a belt conveyor is an apparatus the conveyance speed of which cannot be changed, Z assumes a specific value. In addition, when the conveyance speed of the conveyance apparatus such as a belt conveyor can be changed, the conveyance speed is preferably measured with a conveyance speed measurement apparatus.

However, as will be described later, the modifier is not added when it is determined in step (5) that the modifier is not to be added.

[0043]

Step (7) is a step of adding the target additive amount (B) of the modifier to the raw material when addition of the modifier is necessary but not adding the target additive amount (B) of the modifier to the raw material when addition of the modifier is not necessary.

Accordingly, the modifier can be added to the raw material without an excess or a deficiency only when it is necessary to add the modifier.

[0044]

While a position where the modifier is added to the raw material is preferably a position where the modifier can be added after the measurement position of the moisture percentage of the raw material and the measurement position of the amount of the raw material, the position is not particularly limited and may be midway during the conveyance of the raw material by the conveyance apparatus such as a belt conveyor or after the conveyance of the raw material. From the perspective of adding the modifier in a suitable additive amount, the position where the modifier is added is preferably in a vicinity of the measurement positions of the moisture percentage and the amount of the raw material. In addition, since the added modifier and the raw material are subjected to a mixed action at a transfer part of the belt conveyor, the modifier is preferably added at a position on an upstream side of the transfer part of the belt conveyor.

While a method of adding the modifier to the raw material is not particularly limited, the modifier is preferably sprayed from above the raw material being conveyed by a belt conveyor or the like.

In addition, the modifier may be added at one location or added at two or more locations.

When using two or more components as the modifier, each component may be independently added or a mixture prepared in advance may be added. In addition, after adding one component independently, a mixture of two or more components prepared in advance may be added, or after adding a mixture of two or more components prepared in advance, one component may be independently added.

[0045]

Since the moisture percentage of the raw material may change midway through the conveyance of the raw material, a timing at which the modifier is added to the raw material after a measurement of the moisture percentage of the raw material is preferably within 10 minutes, more preferably within 5 minutes, and even more preferably within 1 minute. In addition, when there is a fluctuation in the conveyance speed of the raw material, the modifier can preferably be added in accordance with the fluctuation.

[0046]

In the present invention, the raw material and the modifier are preferably mixed after adding the modifier to the raw material.

While a mixing method is not particularly limited, a method which causes the raw material and the modifier to be mixed uniformly and which yields a mixture in which the raw material and the modifier are in contact with each other is preferable. Examples of the mixing method include mixing at a transfer part of a belt conveyor and mixing using a kneader or heavy machinery.

In addition, the modifier can also be mixed by adding the modifier to a predetermined container storing the raw material and stirring and mixing the container.

[0047]

While a bulk density of the raw material to which the modifier has been added differs according to a type and characteristics of the raw material, from the perspective of contributing to the improvement of productivity of industrial products using the raw material, the bulk density is preferably more than 700 kg/m³ and more preferably more than 750 kg/m³. [0048]

[Modification apparatus]

The modification apparatus according to the present invention is a modification apparatus which modifies a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the modification apparatus including: a moisture percentage measurement apparatus which continuously measures a moisture percentage of the raw material that is conveyed; a raw material measurement apparatus which continuously measures an amount of the raw material that is present at a specific position of the conveyance equipment; a start/stop measurement apparatus which continuously measures start and stop of the conveyance equipment; a control apparatus which calculates, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material; a control apparatus which determines whether or not addition of the modifier is necessary based on the amount of the raw material and the start and stop; a control apparatus which calculates, based on the amount of the raw material and the target concentration, a target additive amount (B) per unit time of the modifier; and a modifier adding apparatus which adds the target additive amount (B) to the raw material when addition of the modifier is necessary but which does not add the target additive amount (B) to the raw material when addition of the modifier is not necessary, wherein the modification apparatus of a raw material prevents at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, meandering and biasing of the conveyance equipment, and a decline in bulk density of the raw material.

[0049]

The start/stop measurement apparatus may be either a start/stop binary apparatus which measures whether the conveyance equipment has started or stopped and which does not measure a movement speed or a movement speed measurement apparatus of the conveyance equipment.

[0050]

Fig. 1 is a schematic view illustrating an example of the modification apparatus according to an embodiment.

A start/stop measurement apparatus 2 is installed on a belt conveyor 1. A raw material measurement apparatus 3 which continuously measures an amount of the raw material that is present at a specific position of the belt conveyor 1 and a moisture percentage measurement apparatus 4 are installed above the belt conveyor 1. A modifier adding apparatus 6 is installed on a downstream side in a conveying direction of the apparatuses 2 to 4. A control apparatus 5 is connected via wiring or wirelessly to the start/stop measurement apparatus 2, the raw material measurement apparatus 3, the moisture percentage measurement apparatus 4, and the modifier adding apparatus 6.

[0051]

Automation can be realized by using the modification apparatus and preferably by implementing the modification method of a raw material according to the embodiment described earlier, an additive amount of a modifier to the raw material can be controlled to an appropriate amount, and adhesion of the modifier and the raw material to conveyance equipment (such as a BC) can be suppressed.

Reference Signs List

[0052]

1 belt conveyor

2 start/stop measurement apparatus

3 raw material measurement apparatus

4 moisture percentage measurement apparatus

5 control apparatus

6 modifier adding apparatus

10 modification apparatus of raw material

Claims

CLAIMS [Claim 1] A method of modifying a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the method comprising steps of:

(3) continuously measuring start and stop of the conveyance equipment;

[Claim 2]

The modification method of a raw material according to claim 1 , wherein the conveyance equipment is at least one of piping, a belt conveyor, a conveyor chain, a chute, a hopper, a silo, and a coke oven.

[Claim 3]

A modification apparatus which modifies a raw material that is conveyed by conveyance equipment by adding a modifier to the raw material, the modification apparatus comprising: a moisture percentage measurement apparatus which continuously measures a moisture percentage of the raw material that is conveyed; a raw material measurement apparatus which continuously measures an amount of the raw material that is present at a specific position of the conveyance equipment; a start/ stop measurement apparatus which continuously measures start and stop of the conveyance equipment; a control apparatus which calculates, based on the moisture percentage, a target concentration (A) of the modifier in a modifier-added raw material when it is assumed that the modifier has been added to the raw material; a control apparatus which determines whether or not addition of the modifier is necessary based on the amount of the raw material and the start and stop; a control apparatus which calculates, based on the amount of the raw material and the target concentration, a target additive amount (B) per unit time of the modifier; and a modifier adding apparatus which adds the target additive amount (B) to the raw material when addition of the modifier is necessary but which does not add the target additive amount (B) to the raw material when addition of the modifier is not necessary, wherein the modification apparatus of a raw material prevents at least any of adhesion of the raw material to the conveyance equipment, clogging of the raw material inside the conveyance equipment, meandering and biasing of the conveyance equipment, and a decline in bulk density of the raw material.

[Claim 4]

The modification apparatus of a raw material according to claim 3 , wherein the start/ stop measurement apparatus is a start/stop binary apparatus which measures whether the conveyance equipment has started or stopped and which does not measure a movement speed. [Claim 5]

The modification apparatus of a raw material according to claim 3, wherein the start/stop measurement apparatus is a movement speed measurement apparatus of the conveyance equipment.