CN103143432B - Efficient crushing and three-section type screening method of coking coal gravity middings - Google Patents

Abstract

The invention discloses a high-efficiency crushing and three-stage separation method for heavy separation of coking coal, which belongs to the coal crushing, dissociation and separation process. The coking coal coal preparation plant re-selected coal is used as raw material, and it is crushed to 6mm or below 3mm by roll pressing; the material with a particle size of <1mm is deslimed with a desliming screen, and the material with a particle size of 6~1mm or 3~1mm enters the three-product dense medium cyclone Clean coal, medium coal and gangue are obtained after two-stage deintermediation; <1mm particle size material is mixed with clean coal magnetic separator tailings, and then the graded cyclone group is used to remove <0.25mm particle size fine coal slime; Coarse coal slime with particle size of 1~0.25mm enters the interference bed sorter for separation. The light product is dehydrated by a curved screen and a slime centrifuge to obtain coarse clean coal, and the heavy product is dehydrated by a sedimentation filter centrifuge to become tailing coal. ;<0.25mm particle size fine coal slurry enters the flotation machine for flotation, and the foamed clean coal and tailing coal are respectively concentrated, filtered and dehydrated to obtain the flotation clean coal and tailing coal products; Return to mixing bucket. Advantages: Classification and separation of pre-selected coarse and fine-grained coal slime improves the separation accuracy of the equipment.

Description

A high-efficiency crushing and three-stage separation method for coking coal gravity separation

technical field

The invention relates to a coal crushing, dissociation and separation process, in particular to a high-efficiency crushing and three-stage separation method for heavy separation of coking coal.

Background technique

my country has abundant reserves of coal resources and a complete range of coal types, but the resources of coking coal are relatively scarce, accounting for about 27.6%. Among them, fat coal, coking coal and lean coal account for 3.75%, 6.71% and 4.17% of the total coal resources respectively. At present, coking coal and fat coal resources, which are indispensable for the coking industry, have become scarce resources, and their mining, processing and utilization have been protected by national policies or energy strategies. The recovery efficiency of scarce resources is low, and there is an urgent need for a reasonable and efficient separation and recovery process for coking coal.

Contents of the invention

The purpose of the present invention is to provide a high-efficiency crushing and three-stage separation method for coking coal gravity separation, so as to solve the problem of low recovery rate of the existing scarce coking coal.

The purpose of the present invention is achieved in this way, adopt the following technical scheme: take the re-selected coal of the coking coal preparation plant as raw material, adopt the method of crushing and dissociation, desliming before election, coarse, medium and fine-grained three-stage separation, according to the following Steps to proceed:

(1) Use the iron remover to remove the iron sundries in the gravity-selected coal, and then enter the roller crusher 1, the input particle size of the roller crusher 1 is <50mm, and the output particle size is <6mm;

(2) Use the roller crusher 1 to crush the medium coal, and the crushed materials with a particle size of <6mm enter the desliming screen. The desliming screen needs to be added with spray circulating water. When the circulating water is insufficient, clean water is used as a supplement;

(3) Use a desliming sieve with a sieve hole of 1mm to remove the coal slime <1mm in the feed by wet method, and the sieve with a size of 6~1mm enters the mixing tank;

(4) In the mixing tank, after the 6~1mm particle size desilting sieve supernatant is mixed with the crushed material returned by the roller crusher 2, it is pumped to the three-product heavy medium cyclone for sorting, and the three-product heavy medium cyclone is sorted. The medium cyclone is a two-stage equal-density dense medium cyclone, one stage is for swirling force field sorting, and the second stage is for strong swirling flow selection;

(5) The mixture of the mixed material and the qualified medium in the mixing tank is under the cyclone separation of the three-product heavy medium cyclone, the light product enters the clean coal de-mediation sieve, the intermediate product enters the medium coal de-medium sieve, and the heavy The product enters the gangue removal sieve, and the clean coal removal sieve, the medium coal removal sieve and the gangue removal sieve need to add spray circulating water. When the amount of circulating water is insufficient, clean water is used as a supplement;

(6) The first stage of the clean coal removal screen removes the dense medium, and the second stage removes the thin medium, and the sieve becomes a dense medium clean coal product; the clean coal magnetic separator is used to magnetically separate the thin medium, and the magnetic separation concentrate is separated from the first stage. Thick medium enters the qualified medium barrel together;

(7) The first stage of medium coal de-mediation sieve removes the dense medium, the second stage removes the thin medium, and the oversize enters the roller crusher 2; Enter the middle gangue magnetic separator;

(8) The first stage of the gangue removal sieve removes the dense medium, the second stage removes the thin medium, and the sieve becomes gangue products; The dilute medium extracted from the second section of the sieve enters the medium gangue magnetic separator together, and the medium gangue magnetic separator is used to magnetically separate the dilute medium, and the magnetic separation concentrate enters the qualified medium barrel, and the qualified medium in the qualified medium barrel is pumped to the third product The medium cyclone is used as the sorting medium, and the medium density of the qualified medium barrel is adjusted by adding medium or adding clean water;

(9) Under the action of the roller crushing of the roller crusher 2, the material on the medium coal de-mediation sieve is broken into small pieces and returned to the mixing tank;

(10) After mixing the undersize of the desliming screen and the clean coal magnetic separation tailings in the slime tank, pump it to the grading cyclone group for grading. The overflow of the grading cyclone group enters the slurry tank, and the underflow enters the Interference bed separator; the particle size of the overflow is <0.25mm fine coal slime; the underflow particle size is 1~0.25mm coarse coal slime;

(11) Under the separation action of the disturbed bed separator, the light products enter the clean coal arc screen, and the heavy products enter the sedimentation filter centrifuge. The disturbed bed separator needs circulating water/clean water as the top water. When the circulating water tank When the water in the container is insufficient, supplement it with clean water;

(12) Use the clean coal curved screen to dehydrate the light product of the disturbed bed separator once, the oversize material enters the clean coal centrifuge, and the undersize material enters the slurry mixing tank;

(13) Use a clean coal centrifuge to dehydrate the material on the clean coal arc screen for a second time, and the product is coarse clean coal, and the centrifugal liquid enters the slurry mixing tank together with the under matter of the clean coal arc screen;

(14) Use a sedimentation filter centrifuge to dehydrate the heavy product of the interference bed separator, and the product is tailing coal, and the filtrate enters the tailing coal thickener;

(15) After the overflow of the grading cyclone group and the return filtrate of the clean coal filter press, the sieve of the clean coal arc screen and the centrifugate of the clean coal centrifuge are pretreated in the slurry mixing tank, they enter the flotation machine sorting;

(16) Under the separation action of the flotation machine, the foamed clean coal of the flotation machine enters the clean coal filter press, and the tailing coal enters the tailing coal thickener;

(17) Use the clean coal filter press to dehydrate the clean coal of the flotation machine. The product after dehydration is the flotation clean coal product, and the filtrate is returned to the slurry tank;

(18) The tailings of the medium gangue magnetic separation, the tailings of the flotation machine and the centrifugal liquid of the sedimentation filter centrifuge enter the tailings thickener together, the overflow of the thickener enters the circulating pool, and the underflow enters the tailings filter press;

(19) Use the tailing coal filter press to dehydrate the bottom flow of the tailing coal thickener, the product of the filter press is the tailing coal product, and the filtrate enters the circulating pool.

Beneficial effects: Due to the adoption of the above-mentioned scheme, two crushing-coarse, medium and fine-grained grades are respectively used for dense medium separation, disturbed bed separation and flotation three-stage separation process for the rare coking coal heavy separation coal, effectively realizing "Step-by-step release, step-by-step recycling". Crush the gravity-selected coal to a particle size of <6mm to dissociate the lump coal and the mineral intergrowth. The raw coal with a particle size of 6-1mm adopts a three-product dense medium cyclone with mature technology, that is, a two-stage isodensity dense medium cyclone Sorting with a flow device improves the separation accuracy of the coarse-grained class; after the <1mm particle size coal slime is classified by the classifying cyclone group, the 1-0.25mm particle size coarse coal slime is separated by an interference bed sorter, < The 0.25mm fine coal slime is sorted by flotation machine, and the coal product in the three-product dense medium cyclone is crushed by roller crusher for secondary crushing, so that the coal and minerals in the coarse coal can be further dissociated. , greatly improving the separation accuracy and recovery rate of coarse and fine coal slime.

Advantages: after crushing and dissociation of the gravity-selected coal, the three-stage separation process of dense medium separation, disturbed bed separation and flotation is used to pre-select and separate the coarse and fine-grained coal slime, which improves the separation efficiency of the equipment. Accuracy, and recover scarce coking coal resources as much as possible, increase economic, social and ecological benefits.

Description of drawings

Fig. 1 is a process flow chart of the present invention's implementation.

Detailed ways

Embodiment 1: In Fig. 1, the rare coking coal re-selected coal passes through the iron remover near the head of the belt conveyor to remove iron debris, enters the roller crusher 1, and the crushed product enters the wet desliming screen with a sieve hole of 1mm , after the material on the wet desliming sieve is mixed with the return material of the roller crusher 2, it is pumped to the three-product heavy medium cyclone, the light product enters the clean coal de-medium sieve, and the concentrated medium extracted from a section enters the qualified medium barrel , the dilute medium extracted from the second stage enters the clean coal magnetic separator, the magnetically separated concentrate enters the qualified medium barrel, the tailings enter the slime barrel, and the screened material is the dense medium clean coal product; the middle of the third product dense medium cyclone The product enters the medium coal removal sieve, the concentrated medium extracted from the first stage enters the qualified medium barrel, the dilute medium extracted from the second stage enters the medium gangue magnetic separator, the magnetic separation concentrate enters the qualified medium barrel, and the tailings enter the tailings thickener. The material enters the roller crusher 2; the heavy product of the three-product heavy medium cyclone enters the gangue removal screen, the dense medium extracted from the first stage enters the qualified medium barrel, and the thin medium extracted from the second stage enters the medium gangue magnetic separator, and the magnetic separation fine The ore enters the qualified medium barrel, the tailings enter the tailings thickener, and the screened material is the gangue product; the screened material of the desliming screen is mixed with the tailings of the clean coal magnetic separator in the slime tank, and then pumped to the classification rotary Flow device group, the overflow enters the slurry tank, the underflow enters the interference bed separator, the light product of the interference bed separator enters the clean coal arc screen, the clean coal arc screen screen enters the clean coal centrifuge, and the clean coal centrifuge The product of the centrifuge is the coarse clean coal product, and the centrifugal liquid is mixed with the undercut of the clean coal arc screen into the slurry mixing tank; the heavy product of the disturbance bed separator enters the sedimentation filter centrifuge, and the product of the centrifuge is the tailing coal product. The liquid enters the tailing coal thickener; the overflow of the grading cyclone group is mixed with the return filtrate of the clean coal filter press, the sieve of the clean coal arc sieve and the centrifuge liquid of the clean coal centrifuge and enters the slurry mixing barrel, and after slurry pretreatment Enter the flotation machine, the foam product of the flotation machine enters the clean coal filter press, the product of the filter press is the flotation clean coal product, and the filtrate returns to the slurry tank; the tailing coal of the flotation machine enters the tailing coal thickener, and the tailing coal thickener The overflow enters the circulating pool, the underflow of the tailing coal thickener enters the tailing coal filter press, and the filtrate of the tailing coal filter press enters the circulating pool, and the product of the tailing coal filter press is the tailing coal product.

In the process of desliming and descaling, spraying circulating water is required. The disturbed bed sorter needs circulating water/clean water as top water. When the water in the circulating pool is insufficient, clean water is used as a supplement. The dense medium and magnetic separation concentrate from clean coal, medium coal and gangue enter the qualified medium barrel, and when the density of the medium changes, it can be adjusted by adding medium or adding water.

Claims (1)

1. A high-efficiency crushing and three-stage separation method for re-selected coal of coking coal, characterized in that the re-selected coal of coking coal preparation plant is used as raw material, and adopts crushing and dissociation, desliming before selection, coarse, medium and fine-grained The method of three-stage sorting is carried out in accordance with the following steps: (1) Use the iron remover to remove the iron sundries in the gravity-selected coal, and then enter the roller crusher 1, the input particle size of the roller crusher 1 is <50mm, and the output particle size is <6mm; (2) Use the roller crusher 1 to crush the medium coal, and the crushed materials with a particle size of <6mm enter the desliming screen. The desliming screen needs to be added with spray circulating water. When the circulating water is insufficient, clean water is used as a supplement; (3) Use a desliming sieve with a sieve hole of 1mm to remove the coal slime <1mm in the feed by wet method, and the sieve with a size of 6~1mm enters the mixing tank; (4) In the mixing tank, after the 6~1mm particle size desilting sieve supernatant is mixed with the crushed material returned by the roller crusher 2, it is pumped to the three-product heavy medium cyclone for sorting, and the three-product heavy medium cyclone is sorted. The medium cyclone is a two-stage equal-density dense medium cyclone, one stage is for swirling force field sorting, and the second stage is for strong swirling flow selection; (5) The mixture of the mixed material and the qualified medium in the mixing tank is under the cyclone separation of the three-product heavy medium cyclone, the light product enters the clean coal de-mediation sieve, the intermediate product enters the medium coal de-medium sieve, and the heavy The product enters the gangue removal sieve, and the clean coal removal sieve, the medium coal removal sieve and the gangue removal sieve need to add spray circulating water. When the amount of circulating water is insufficient, clean water is used as a supplement; (6) The first stage of the clean coal removal screen removes the dense medium, and the second stage removes the thin medium, and the sieve becomes a dense medium clean coal product; the clean coal magnetic separator is used to magnetically separate the thin medium, and the magnetic separation concentrate is separated from the first stage. Thick medium enters the qualified medium barrel together; (7) The first stage of medium coal de-mediation sieve removes the dense medium, the second stage removes the thin medium, and the oversize enters the roller crusher 2; Enter the middle gangue magnetic separator; (8) The first stage of the gangue removal sieve removes the dense medium, the second stage removes the thin medium, and the sieve becomes gangue products; The dilute medium extracted from the second section of the sieve enters the medium gangue magnetic separator together, and the medium gangue magnetic separator is used to magnetically separate the dilute medium, and the magnetic separation concentrate enters the qualified medium barrel, and the qualified medium in the qualified medium barrel is pumped to the third product The medium cyclone is used as the sorting medium, and the medium density of the qualified medium barrel is adjusted by adding medium or adding clean water; (9) Under the action of the roller crushing of the roller crusher 2, the material on the medium coal de-mediation sieve is broken into small pieces and returned to the mixing tank; (10) After mixing the undersize of the desliming screen and the clean coal magnetic separation tailings in the slime tank, pump it to the grading cyclone group for grading. The overflow of the grading cyclone group enters the slurry tank, and the underflow enters the Interference bed separator; the particle size of the overflow is <0.25mm fine coal slime; the underflow particle size is 1~0.25mm coarse coal slime; (11) Under the separation action of the disturbed bed separator, the light products enter the clean coal arc screen, and the heavy products enter the sedimentation filter centrifuge. The disturbed bed separator needs circulating water/clean water as the top water. When the circulating water tank When the water in the container is insufficient, supplement it with clean water; (12) Use the clean coal curved screen to dehydrate the light product of the disturbed bed separator once, the oversize material enters the clean coal centrifuge, and the undersize material enters the slurry mixing tank; (13) Use a clean coal centrifuge to dehydrate the material on the clean coal arc screen for a second time, and the product is coarse clean coal, and the centrifugal liquid enters the slurry mixing tank together with the under matter of the clean coal arc screen; (14) Use a sedimentation filter centrifuge to dehydrate the heavy product of the interference bed separator, and the product is tailing coal, and the filtrate enters the tailing coal thickener; (15) After the overflow of the grading cyclone group and the return filtrate of the clean coal filter press, the sieve of the clean coal arc screen and the centrifugate of the clean coal centrifuge are pretreated in the slurry mixing tank, they enter the flotation machine sorting; (16) Under the separation action of the flotation machine, the foamed clean coal of the flotation machine enters the clean coal filter press, and the tailing coal enters the tailing coal thickener; (17) Use the clean coal filter press to dehydrate the clean coal of the flotation machine. The product after dehydration is the flotation clean coal product, and the filtrate is returned to the slurry tank; (18) The tailings of the medium gangue magnetic separation, the tailings of the flotation machine and the centrifugal liquid of the sedimentation filter centrifuge enter the tailings thickener together, the overflow of the thickener enters the circulating pool, and the underflow enters the tailings filter press; (19) Use the tailing coal filter press to dehydrate the bottom flow of the tailing coal thickener, the product of the filter press is the tailing coal product, and the filtrate enters the circulating pool.