Smelting reduction is a front iron making technology for the 21st century. It can produce liquid iron by direct using common coal but not charred coal. The process has many attractive advantages such as concise flow, ...Smelting reduction is a front iron making technology for the 21st century. It can produce liquid iron by direct using common coal but not charred coal. The process has many attractive advantages such as concise flow, low investment and production cost, low environmental pollution and high quality molten iron. Combined with a reciprocal chemical technology, energy efficiency can be further improved by transforming mass coal gas, by-produced in smelting reduction,into dimethyl ether, a clean fuel. Method and characteristics of the combined technology are discussed in this paper.展开更多
In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China＇ s refractories industry in ...In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China＇ s refractories industry in production capacity, in quality improvement and in development of new products. Sophisticated high performance refractory materials mainly based on our rich reserves of magncsite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables. They have been used in blast furnaces, BOFs, EAFs, secondary refining and continuous casting with considerable improvement in service pecformance.展开更多
As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） an...As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） and Anti- nodulizing Complex Factor （K1） have an important influence on property of DI, depending on the Mn and P level, the metallurgical quality of iron melt, rare earth （RE） and inoculation. It was also found that the influence of Mn is depended on the phosphorus and residual elements level in ductile iron. Less than 0.03%P and 0.2%Mn and P〈2.0 are the basic conditions to obtain as-cast ferritic structure. At the same lower level of Mn and P, the increasing of residual elements （P〉2.0） determines presence of pearlite in as-cast structure, while ferrite structure is obtained after a short annealing heat treatment. Lower level of phosphorus （P〈0.025%） and residual elements （Px〈2.0） allow to use relative high Mn content （0.32%-0.38%）, in condition of ferritic structure, including in as-cast state. High P （0.04%- 0.045%） and Mn （0.25%-0.35%） content stabilized peadite, especially at lower level of residual elements （P 〈2.0）. Antinodulizing action of elements was counteracted up to K1=2.0 level, by RE included in Mg-treatment alloy, which are beneficial for K1〈1.2 and compulsory for K1〉1.2. Si has a significant influence on the mechanical properties of heat treated ductile irons： an important decreasing of elongation level and a moderate increasing of yield and tensile strength and their ratio in 150-170 HB typical hardness field. A typical final chemical composition for as-cast 400-18 ductile iron could include 3.5%-3.7%C, 2.4%-2.5%Si, max.0.18%Mn, max.0.025%P, max.0.01%S, 0.04%-0.05%Mg for Px〈1.5 and K1〈1.1. High purity pig iron, RE-bearing FeSiMg and powerful inoculant are also recommended.展开更多
A1203-SiC-C iron trough castables were prepared using high alumina bauxite clinker GL-90 （ 〉 1 mm ） or homogenized bauxite GL-88 to replace the traditional brown corundum aggregates （ 〉 1 mm ） to reduce the cost...A1203-SiC-C iron trough castables were prepared using high alumina bauxite clinker GL-90 （ 〉 1 mm ） or homogenized bauxite GL-88 to replace the traditional brown corundum aggregates （ 〉 1 mm ） to reduce the cost of iron trough castables. Effects of the two bauxite aggregates on properties of iron trough eastables were investigated. The results show that the two kinds of bauxite affect flowability, bulk density, strength and slag corrosion resistance of trough castables differently. Compared with homogenized bauxite, high alumina bauxite clinker is more suitable to substitute brown corundum. The castables prepared from the bauxite clinker have similar performances with those prepared from brown corundum, especially used in medium or small blast furnaces with weak thermal impact and lower temperature hot metal. However, in large blast furnaces with severe thermal impact and high temperature hot metal, the performances of the two castables are significantly different. So it is suggested to use the brown corundum based castables in the front gyral zone of the slag skimmer.展开更多
Objective: With regard to the 2010 edition of Dietary Reference Intakes for Japanese (DRIs-2010), we investigated whether the DRIs for two age groups, breast-fed infants aged 6-8 and 9-11 months, can be fulfilled for ...Objective: With regard to the 2010 edition of Dietary Reference Intakes for Japanese (DRIs-2010), we investigated whether the DRIs for two age groups, breast-fed infants aged 6-8 and 9-11 months, can be fulfilled for every nutrient in actual dietary practice. Design: We evaluated (1) whether the DRIs for all nutrients can be fulfilled in a formula with energy and protein exceeding their DRIs, (2) whether the DRIs for all nutrients can be fulfilled in a formula prepared in accordance with Japanese government-recommended weaning guidelines, and (3) what kinds of formulas can be prepared if the DRIs for all nutrients are fulfilled without referring to the weaning guidelines. Setting: Simulation of diet menu on the basis of published data in our university and survey of diet menu in a university hospital attached to a national medical school. Subjects: The three types of formulas were planned for ten days. Results: It was impossible to simultaneously fulfil the DRIs for 6 - 8-month-old infants concerning pantothenic acid, vitamin D, and iron and those for 9 - 11-month-old infants concerning these nutrients plus protein. Conclusion: According to the DRIs-2010, the DRI for all nutrients could not be fulfilled in an ingestible formula.展开更多
1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of tra...1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of traditional iron&steel making technology with continuous regeneration;②Three major frontier techniques of metallurgy(smelting reduction;near-net-shape continuous展开更多
The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted oc...The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P31c; a=15.943(2), c=17.612(4)? V=3877.0(12)?, Z=4, Dc=1.325g/cm3, m=0.445mm-1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2s(I). The bond lengths from iron to oxygens are 1.980(1)?for the ketone oxygens and 2.071(1)?for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37. The dihedral angles are 0.5(2)?between chelate ring plane and pyridine ring plane and 71.31(7)?between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1)? respectively.展开更多
Effects of FeO content （0, 5%, 10%, and 15% in mass, respectively ） in lab-synthesized smelting redttc- tion slag with iron bath and test temperature （1 450, 1 500, 1550, anti 1 600 ℃ ） on corrosion am,amount and...Effects of FeO content （0, 5%, 10%, and 15% in mass, respectively ） in lab-synthesized smelting redttc- tion slag with iron bath and test temperature （1 450, 1 500, 1550, anti 1 600 ℃ ） on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that ： （ 1 ） the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; （2） the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.展开更多
A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ...A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ctrode, while the alloy rod as an anode electrode. The conventional rotating ele ctrode process must have an anode with pre-melting alloys; however, in this new process, using pure iron as cathode electrode and pure aluminum as anode electr ode can eliminate the step of pre-melting. The effects of process variables, which include electrode rotational speed, a nd electrode diameter of the mean particle diameter were determined. Results showed that both the rotational speed and diameter of electrodes would a ffect the mean diameter of particles. There are three kinds of powders with diff erent composition produced in this study and the possible mechanisms are discuss ed. The process parameters and volume mean diameter of the powders have been cor related to find an experimental equation. The results show that when the rotational speed and the diameter of the anode el ectrode are increased, the powders size will decrease. However, the powders size will increase with cathode electrode.展开更多
Reaction of FeCIz＇6H20, pyridine-2,4,6-tricarboxylic acid（H3pyta） and NaOH in the hydrothermal system at 185 ℃ resulted in the formation of 1D coordination polymer[Fe（Hpyta）（H2O）2]（1） based on Fe-Hpyta chain...Reaction of FeCIz＇6H20, pyridine-2,4,6-tricarboxylic acid（H3pyta） and NaOH in the hydrothermal system at 185 ℃ resulted in the formation of 1D coordination polymer[Fe（Hpyta）（H2O）2]（1） based on Fe-Hpyta chains. When the abpt[abpt=-4-amino-3,5-bis（4-pyridyl）-l,2,4-triazole] ligand was employed in the reaction system, a 3D supramolecular porous network （H2bpt）[Fe（pyta）（H2O）2]·4H2O（2） was obtained. The framework was constructed with negative （Fe-pyta） chains and the positive H3bpt^＋ in situ, formed from the abpt reagent, to form 1D channels filled with guest water molecules via hydrogen-bonds. X-Ray diffraction crystal structure analysis shows that complex 1 crystallized in the monoclinic system, space group C2/c, a=1.1490（5） nm, b=0.9008（4） nm, c=1.0058（5） nm, B=107.254（9）°, V=0.9942（8） nm3, Z=4; and complex 2 crystallizes in the triclinic system, space group P1 with a=0.90392（11） nm, b=0.96027（11 ） nm, c=1.55540（18） nm, a=73.558（2）°,B= 86.126（2）°,r= 68.745（2）°, V=1.2059（2） nm^3 and Z=2.展开更多
This paper reviews the present development situation of refractories for iron making system in China, which includes blast furnace, hot blast stove and coke dry quenching, etc. Varieties and performances of refractori...This paper reviews the present development situation of refractories for iron making system in China, which includes blast furnace, hot blast stove and coke dry quenching, etc. Varieties and performances of refractories used by the top steel and iron groups such as Baosteel, Wuhan I＆S Group and Anshan I＆S Group for iron making were exemplified and concerned problems were analyzed, together with solutions and suggestions for future refractories R＆D work.展开更多
Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geo...Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.展开更多
Selection of the crusher required a great deal of design regarding to the mine planning. Selection of suitable primary crusher from all of available primary crushers is a multi-criterion decision making(MCDM) problem....Selection of the crusher required a great deal of design regarding to the mine planning. Selection of suitable primary crusher from all of available primary crushers is a multi-criterion decision making(MCDM) problem. The present work explores the use of technique for order performance by similarity to ideal solution(TOPSIS) with fuzzy set theory to select best primary crusher for Golegohar Iron Mine in Iran. Gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impact crusher, hammer mill and feeder breaker crushers have been considered as alternatives. Also, the capacity, feed size, product size, rock compressive strength, abrasion index and application of primary crusher for mobile plants were considered as criteria for solution of this MCDM problem. To determine the order of the alternatives, closeness coefficient is defined by calculating the distances to the fuzzy positive ideal solution(FPIS) and fuzzy negative ideal solution(FNIS). Results of our work based on fuzzy TOPSIS method show that the gyratory is the best primary crusher for the studied mine.展开更多
文摘Smelting reduction is a front iron making technology for the 21st century. It can produce liquid iron by direct using common coal but not charred coal. The process has many attractive advantages such as concise flow, low investment and production cost, low environmental pollution and high quality molten iron. Combined with a reciprocal chemical technology, energy efficiency can be further improved by transforming mass coal gas, by-produced in smelting reduction,into dimethyl ether, a clean fuel. Method and characteristics of the combined technology are discussed in this paper.
文摘In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China＇ s refractories industry in production capacity, in quality improvement and in development of new products. Sophisticated high performance refractory materials mainly based on our rich reserves of magncsite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables. They have been used in blast furnaces, BOFs, EAFs, secondary refining and continuous casting with considerable improvement in service pecformance.
文摘As-cast and heat-treated 400-18 ductile iron （DI） grade was obtained in different foundry conditions, as metallic charge, Mg-treatment alloy and inoculation. It was found that the Pearlitic Influence Factor （P） and Anti- nodulizing Complex Factor （K1） have an important influence on property of DI, depending on the Mn and P level, the metallurgical quality of iron melt, rare earth （RE） and inoculation. It was also found that the influence of Mn is depended on the phosphorus and residual elements level in ductile iron. Less than 0.03%P and 0.2%Mn and P〈2.0 are the basic conditions to obtain as-cast ferritic structure. At the same lower level of Mn and P, the increasing of residual elements （P〉2.0） determines presence of pearlite in as-cast structure, while ferrite structure is obtained after a short annealing heat treatment. Lower level of phosphorus （P〈0.025%） and residual elements （Px〈2.0） allow to use relative high Mn content （0.32%-0.38%）, in condition of ferritic structure, including in as-cast state. High P （0.04%- 0.045%） and Mn （0.25%-0.35%） content stabilized peadite, especially at lower level of residual elements （P 〈2.0）. Antinodulizing action of elements was counteracted up to K1=2.0 level, by RE included in Mg-treatment alloy, which are beneficial for K1〈1.2 and compulsory for K1〉1.2. Si has a significant influence on the mechanical properties of heat treated ductile irons： an important decreasing of elongation level and a moderate increasing of yield and tensile strength and their ratio in 150-170 HB typical hardness field. A typical final chemical composition for as-cast 400-18 ductile iron could include 3.5%-3.7%C, 2.4%-2.5%Si, max.0.18%Mn, max.0.025%P, max.0.01%S, 0.04%-0.05%Mg for Px〈1.5 and K1〈1.1. High purity pig iron, RE-bearing FeSiMg and powerful inoculant are also recommended.
文摘A1203-SiC-C iron trough castables were prepared using high alumina bauxite clinker GL-90 （ 〉 1 mm ） or homogenized bauxite GL-88 to replace the traditional brown corundum aggregates （ 〉 1 mm ） to reduce the cost of iron trough castables. Effects of the two bauxite aggregates on properties of iron trough eastables were investigated. The results show that the two kinds of bauxite affect flowability, bulk density, strength and slag corrosion resistance of trough castables differently. Compared with homogenized bauxite, high alumina bauxite clinker is more suitable to substitute brown corundum. The castables prepared from the bauxite clinker have similar performances with those prepared from brown corundum, especially used in medium or small blast furnaces with weak thermal impact and lower temperature hot metal. However, in large blast furnaces with severe thermal impact and high temperature hot metal, the performances of the two castables are significantly different. So it is suggested to use the brown corundum based castables in the front gyral zone of the slag skimmer.
文摘Objective: With regard to the 2010 edition of Dietary Reference Intakes for Japanese (DRIs-2010), we investigated whether the DRIs for two age groups, breast-fed infants aged 6-8 and 9-11 months, can be fulfilled for every nutrient in actual dietary practice. Design: We evaluated (1) whether the DRIs for all nutrients can be fulfilled in a formula with energy and protein exceeding their DRIs, (2) whether the DRIs for all nutrients can be fulfilled in a formula prepared in accordance with Japanese government-recommended weaning guidelines, and (3) what kinds of formulas can be prepared if the DRIs for all nutrients are fulfilled without referring to the weaning guidelines. Setting: Simulation of diet menu on the basis of published data in our university and survey of diet menu in a university hospital attached to a national medical school. Subjects: The three types of formulas were planned for ten days. Results: It was impossible to simultaneously fulfil the DRIs for 6 - 8-month-old infants concerning pantothenic acid, vitamin D, and iron and those for 9 - 11-month-old infants concerning these nutrients plus protein. Conclusion: According to the DRIs-2010, the DRI for all nutrients could not be fulfilled in an ingestible formula.
文摘1 Introduction The 21st century is coming and the world iron and steel making technology is facing an important technical evolution at this century turnover,which is reflected in two aspects:①Rapid development of traditional iron&steel making technology with continuous regeneration;②Three major frontier techniques of metallurgy(smelting reduction;near-net-shape continuous
基金the Foundation of Returning Personal from Overseas Study of Jiangsu Education Department.
文摘The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P31c; a=15.943(2), c=17.612(4)? V=3877.0(12)?, Z=4, Dc=1.325g/cm3, m=0.445mm-1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2s(I). The bond lengths from iron to oxygens are 1.980(1)?for the ketone oxygens and 2.071(1)?for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37. The dihedral angles are 0.5(2)?between chelate ring plane and pyridine ring plane and 71.31(7)?between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1)? respectively.
文摘Effects of FeO content （0, 5%, 10%, and 15% in mass, respectively ） in lab-synthesized smelting redttc- tion slag with iron bath and test temperature （1 450, 1 500, 1550, anti 1 600 ℃ ） on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that ： （ 1 ） the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; （2） the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.
文摘A new process was used for producing FeAl alloy pow de rs with double consumable rotating electrodes and the powders made in this appar atus were analyzed. In this new technology, tungsten rod serves as a cathode ele ctrode, while the alloy rod as an anode electrode. The conventional rotating ele ctrode process must have an anode with pre-melting alloys; however, in this new process, using pure iron as cathode electrode and pure aluminum as anode electr ode can eliminate the step of pre-melting. The effects of process variables, which include electrode rotational speed, a nd electrode diameter of the mean particle diameter were determined. Results showed that both the rotational speed and diameter of electrodes would a ffect the mean diameter of particles. There are three kinds of powders with diff erent composition produced in this study and the possible mechanisms are discuss ed. The process parameters and volume mean diameter of the powders have been cor related to find an experimental equation. The results show that when the rotational speed and the diameter of the anode el ectrode are increased, the powders size will decrease. However, the powders size will increase with cathode electrode.
基金the Scientific and Technological Project of Guangdong Province, China(No.2006B36703005)
文摘Reaction of FeCIz＇6H20, pyridine-2,4,6-tricarboxylic acid（H3pyta） and NaOH in the hydrothermal system at 185 ℃ resulted in the formation of 1D coordination polymer[Fe（Hpyta）（H2O）2]（1） based on Fe-Hpyta chains. When the abpt[abpt=-4-amino-3,5-bis（4-pyridyl）-l,2,4-triazole] ligand was employed in the reaction system, a 3D supramolecular porous network （H2bpt）[Fe（pyta）（H2O）2]·4H2O（2） was obtained. The framework was constructed with negative （Fe-pyta） chains and the positive H3bpt^＋ in situ, formed from the abpt reagent, to form 1D channels filled with guest water molecules via hydrogen-bonds. X-Ray diffraction crystal structure analysis shows that complex 1 crystallized in the monoclinic system, space group C2/c, a=1.1490（5） nm, b=0.9008（4） nm, c=1.0058（5） nm, B=107.254（9）°, V=0.9942（8） nm3, Z=4; and complex 2 crystallizes in the triclinic system, space group P1 with a=0.90392（11） nm, b=0.96027（11 ） nm, c=1.55540（18） nm, a=73.558（2）°,B= 86.126（2）°,r= 68.745（2）°, V=1.2059（2） nm^3 and Z=2.
文摘This paper reviews the present development situation of refractories for iron making system in China, which includes blast furnace, hot blast stove and coke dry quenching, etc. Varieties and performances of refractories used by the top steel and iron groups such as Baosteel, Wuhan I＆S Group and Anshan I＆S Group for iron making were exemplified and concerned problems were analyzed, together with solutions and suggestions for future refractories R＆D work.
文摘Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.
文摘Selection of the crusher required a great deal of design regarding to the mine planning. Selection of suitable primary crusher from all of available primary crushers is a multi-criterion decision making(MCDM) problem. The present work explores the use of technique for order performance by similarity to ideal solution(TOPSIS) with fuzzy set theory to select best primary crusher for Golegohar Iron Mine in Iran. Gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impact crusher, hammer mill and feeder breaker crushers have been considered as alternatives. Also, the capacity, feed size, product size, rock compressive strength, abrasion index and application of primary crusher for mobile plants were considered as criteria for solution of this MCDM problem. To determine the order of the alternatives, closeness coefficient is defined by calculating the distances to the fuzzy positive ideal solution(FPIS) and fuzzy negative ideal solution(FNIS). Results of our work based on fuzzy TOPSIS method show that the gyratory is the best primary crusher for the studied mine.
