CN115646638A - A fine separation process for gasification slag - Google Patents

Abstract

The invention provides a fine separation process of gasification slag, which includes: mixing the gasification slag in the slag field with water, and then passing through a linear vibrating screen to classify and remove particles with a particle size greater than 2 mm, and then using a composite hydrocyclone to sort the particle size For gasification slag less than or equal to 2mm, the overflow product of the composite water-medium cyclone is separated again by a pulse disturbance bed separator, and the overflow and desliming of the composite water-medium cyclone with a particle size of less than or equal to 0.1mm is separated by a flotation column Under-screen pulp and pulse separator overflow desliming under-screen pulp. Finally, three products are obtained: low-ash coal, medium-ash coal, and tailings. The process has strong adaptability to gasification slag, and all the sorted products can be effectively utilized, reducing environmental pollution and waste of resources by gasification slag.

Description

A fine separation process for gasification slag

technical field

The invention belongs to the technical field of solid waste resource utilization, in particular to a gasification slag fine sorting process.

Background technique

In recent years, with the rapid development of the coal chemical industry, the amount of gasification slag produced in the coal gasification process has continued to increase. Gasification slag is mainly composed of a large amount of inorganic minerals and a small amount of unburned carbon, and the treatment methods are mainly stockpiling and landfilling, which not only wastes resources, but also causes serious pollution to the ecological environment. Therefore, how to efficiently recycle gasification slag has become an urgent problem to be solved.

At present, the main methods for sorting residual carbon in gasification slag are flotation and gravity separation. However, when gasification slag is separated by flotation, due to the well-developed gasification fine slag pores and large specific surface area, the consumption of reagents is large, the flotation index is not ideal, and the economic cost is high; the gravity separation method is used to separate gasification slag When the carbon residue is medium, due to the small particle size of the gasification slag, it is difficult to effectively separate the carbon ash in a single gravity field, and it is difficult to achieve a better separation effect.

Contents of the invention

In order to overcome the above technical problems, the purpose of the present invention is to provide a fine separation process for gasification slag, which has the characteristics of good separation effect and high economic benefit by making full use of the gravity separation method and flotation method. The process has strong adaptability to gasification slag, and all the sorted products can be effectively utilized, reducing environmental pollution and waste of resources by gasification slag.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A gasification slag fine separation process, comprising the following steps;

The gasification slag enters the mixing tank 2 through the belt conveyor 1 and is mixed with water to prepare a pulp a. The obtained pulp a is sent to a vibrating screen 3 with a sieve hole diameter of 2mm for dehydration and classification, and removes the gasification slag and Impurities, the product on the sieve becomes tailings b after dehydration;

The under-screen pulp c enters the mixing tank 4 for pulp mixing, and the pulp with a pulp concentration of 20% to 30% is prepared and fed tangentially to the composite water-medium cyclone 6 through the slurry pump 5 for sorting;

The underflow product d and the overflow product e are separated by the composite hydrocyclone 6. The underflow product d is dehydrated through the dehydration screen 7 with a sieve diameter of 0.074mm. Machine 22; the overflow product e of the composite hydrocyclone 6 passes through the desliming screen 8 with a sieve diameter of 0.1 mm for desliming, and after desliming, the product h on the sieve enters the mixing tank 9 and mixes with water to make ore pulp and passes through the slurry pump 10 is fed into the disturbed bed sorter 11 for re-sorting, and the pulp i under the desliming screen 8 enters the pulp preprocessor 16;

The interference bed separator 11 sorts again to obtain the underflow product j and the overflow product k. The underflow product j passes through the dehydration screen 12 with a sieve diameter of 0.074 mm for dehydration. Concentrator 22; the overflow product k is deslimed through the desliming screen 13 with a sieve diameter of 0.1 mm, and the oversieved product n enters the centrifuge 14 for dehydration after desliming, and the underscreen pulp o enters the pulp preprocessor 16;

After the dehydration of the centrifuge 14, the product becomes low-ash coal p, and the filtrate q enters the concentrator 22; the under-screen pulp i and the under-screen pulp o pass through the pulp preprocessor 16 after pulping and chemical tank 15 dosing, and then pass through the feeding pump 17 is fed into the flotation column 18 for flotation, the flotation tailings r enters the concentrator 22, and the flotation concentrate s enters the filter press into the barrel 19 and is fed into the filter press 21 through the feed pump 20 for dehydration by press filtration. The filter cake becomes medium ash coal t, and the filtrate u enters the circulating water tank 25 and is used as circulating water.

The separation method finally obtains three products: low ash coal, medium ash coal and tailings.

The sieve water g, sieve water m, filtrate q and flotation tailings r enter the concentrator 22 for concentration, the concentrated overflow w enters the circulating water pool 25 for use as circulating water, and the concentrated underflow v is fed through the press filter feeding pump 23 The filter press 24 presses and dehydrates, and the filter cake becomes tailings x after dehydration, and the filtrate y enters the circulating water pool 25 for circulating water use;

A part of the circulating water in the circulating pool 25 is fed into the mixing tank 2, the mixing tank 4 and the mixing tank 9 using the clear water pump 26 for slurry mixing, and a part is used as supplementary water for the composite hydrocyclone 6 and the disturbed bed separator 11 And sieving equipment spray water.

After the desliming, the pulp i and the pulp o can also be directly entered into the thickener 22 for concentration without flotation, and become tailings after being filtered by the filter press 24 .

The vibrating screen 3 is a linear single-layer vibrating screen, the model is ZS type.

The diameter of the composite hydrocyclone (6) is 200mm, and the cone angle is 80°-150°;

Further, the diameter of the secondary water inlet hole in the 6 cylindrical sections of the composite hydrocyclone is 3mm, which is 45° to the tangent.

Further, the secondary water fed tangentially at a certain pressure forms a medium resistance facing the axis in the composite hydrocyclone (6), which enhances the effective stratification and efficient separation of the gasification slag according to the density difference The separation effect improves the separation accuracy of the composite hydrocyclone.

The dewatering screen 7, the dewatering screen 12, the desliming screen 8 and the desliming screen 13 are high-frequency vibrating screens.

The interference bed separator 11 can choose TBS or a cascade pulse separator with a diameter of 1000mm.

The centrifuge 14 is a decanter centrifugal dehydrator.

The thickener 22 can be a deep cone thickener or a high-efficiency thickener.

Beneficial effects of the present invention:

The gasification slag fine separation process of the present invention connects the two composite force field coal preparation methods of composite hydrocyclone separation and disturbed bed separation with flotation, which makes up for the single force field separation gas separation process. The shortcoming of poor slag effect; at the same time, it also reduces the amount of material entering the flotation, reducing the cost of flotation, effectively enriching the unburned carbon particles in the gasification slag step by step, and maximizing the realization of the unburned carbon particles in the gasification slag. Carbon recycling. The low-ash coal obtained after gasification slag separation can be used as activated carbon, electrode materials, etc.; the medium-ash coal obtained after separation can be used as power coal for boiler co-firing, etc.; the tailings obtained after separation can be used as building materials , downhole filling raw materials, etc. The process has strong adaptability to gasification slag, uses water as the separation medium, does not need to add heavy medium, and pre-eliminates high-ash tailings through vibrating screen classification and composite water-medium cyclone one-time separation to reduce entering the disturbance bed Feed amount, further reduce the feed amount of flotation, reduce energy consumption, save production cost; at the same time, realize the closed loop circulation of coal slime water, all the products after sorting are effectively used, reducing environmental pollution and waste of resources .

Description of drawings:

Fig. 1 is a process flow chart of gasification slag sorting in the present invention.

Fig. 2 is a structural diagram of equipment for gasification slag sorting according to the present invention.

In Fig. 2: 1-belt conveyor, 2, 4, 9-stirring barrel, 3-linear vibrating screen, 5, 10, 17, 20, 23-slurry pump, 6-composite hydrocyclone, 7, 12 -High-frequency vibrating dewatering screen, 8, 13-High-frequency vibrating desliming screen, 11-pulse separator, 14-sediment centrifugal dehydrator, 15-medicine tank, 16-pulp preprocessor, 18-flotation column , 19-pulp buffer barrel, 21, 24-plate and frame filter press, 22-deep cone thickener, 25-circulating pool, 26-clean water pump.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1 and Figure 2, the gasification slag fine separation process of the present invention, the steps are as follows:

The gasification slag from the slag field enters the mixing tank 2 through the belt conveyor 1 and mixes with water to prepare a pulp a. The outlet of the mixing tank 2 is connected to the feed port of the linear vibrating screen 3, and the obtained pulp is fed into the linear vibrating screen 3 with a screen hole diameter of 2 mm. Classification is carried out to remove gasification slag and impurities with a particle size greater than 2mm in the gasification slag slurry, and the product on the sieve becomes tailings b after dehydration;

The pulp c under the screen enters the mixing tank 4 for pulp mixing, and the pulp with a pulp concentration of 20% is prepared and fed tangentially through the slurry pump 5 to the composite hydrocyclone 6 with a diameter of 200mm and a cone angle of 120° for separation ;

The overflow port of the compound hydrocyclone 6 is connected to the feed port 8 of the high-frequency vibrating desliming screen, and the bottom flow port is connected to the feed port 7 of the high-frequency vibrating dehydration screen. The dewatering screen 7 is used for dehydration. After dehydration, the product on the sieve becomes tailings f, and the water g under the sieve enters the deep cone thickener 22; the overflow product e of the composite hydrocyclone 6 passes through the high-frequency vibrating desliming screen with a sieve diameter of 0.1mm 8 for desliming. After desliming, the product h on the sieve enters the mixing tank 9 and mixes with water to make a pulp through a slurry pump 10 and feeds it into a pulse separator 11 with a diameter of 1000 mm for re-separation. The desliming screen 8 sieves the pulp i enters the pulp preprocessor 16;

The underflow product j obtained by re-sorting by the pulse separator 11 is dehydrated through a high-frequency vibrating dewatering screen 12 with a sieve diameter of 0.074 mm. After dehydration, the product on the sieve becomes medium ash coal l, and the water m under the sieve enters the deep cone thickener 22; The overflow product k obtained by re-sorting by the pulse separator 11 is deslimed through a high-frequency vibrating desliming screen 13 with a sieve diameter of 0.1mm. The final product becomes low-ash coal p, and the filtrate q enters the deep cone thickener 22; the under-screen pulp o enters the pulp preprocessor 16;

The under-screen pulp i and under-screen pulp o enter the pulp preprocessor 16 through the pipeline to mix with water, and after adding the medicine through the chemical tank 15, they are fed into the short-column flotation column 18 by the flotation feeding pump 17 for further processing. Flotation, the flotation tailings r enter the deep cone thickener 22, the flotation concentrate s enters the buffer tank 19, and is fed into the plate and frame filter press 21 through the slurry pump 20 for dehydration, and the dehydrated filter cake becomes medium ash coal t, the filtrate u enters the circulating water tank 25 and uses it as circulating water;

Sieve water g, sieve water m, filtrate q, and flotation tailings r are collected through pipelines and enter the deep cone thickener 22 from the feed port. The concentrated overflow w enters the circulating water pool 25 for use as circulating water. The material pump 23 is fed into the plate and frame filter press 24 for pressure filtration and dehydration. After dehydration, the filter cake becomes tailings x, and the filtrate y enters the circulating water pool 25 for use as circulating water;

The circulating water in the circulating water pool 25 uses a part of the clear water pump 26 to feed the mixing tank 2, the mixing tank 4 and the mixing tank 9 for slurry mixing, and a part is used as the supplementary water and The screening equipment is sprayed with water.

Claims (10)

1. A gasification slag fine separation process is characterized in that, comprising the following steps; The gasification slag enters the mixing tank (2) through the belt conveyor (1) and mixes with water to prepare a pulp a, and the obtained pulp a is sent to a vibrating screen with a sieve diameter of 2mm (3) for dehydration and classification, and the particle size of the gasification slag pulp is larger than 2mm of gasification slag and impurities, the product on the sieve becomes tailings b after dehydration; The under-screen pulp c enters the mixing tank (4) for pulp mixing, and the pulp with a pulp concentration of 20% to 30% is prepared and fed tangentially to the composite hydrocyclone (6) through the slurry pump (5) for sorting; The composite hydrocyclone (6) separates the underflow product d and the overflow product e. The underflow product d is dehydrated through a dehydration screen (7) with a sieve diameter of 0.074 mm. After dehydration, the product on the sieve becomes tailings f. The lower water g enters the concentrator (22); the overflow product e of the composite hydrocyclone (6) is deslimed through a 0.1 mm desliming sieve (8), and the deslimed product h enters the mixing tank ( 9) mix with water to make pulp and feed it into the disturbed bed sorter (11) through the slurry pump (10) for re-sorting, and the pulp i under the desliming screen (8) enters the pulp preprocessor (16); The disturbed bed sorter (11) sorts again to obtain the underflow product j and the overflow product k, and the underflow product j is dehydrated through a dehydration screen (12) with a sieve diameter of 0.074 mm, and the product on the sieve after dehydration becomes medium ash coal l, The sieved water m enters the concentrator (22); the overflow product k passes through a 0.1mm desliming screen (13) for desliming, and after desliming, the sieved product n enters a centrifuge (14) for dehydration, and the sieved pulp o enter the pulp preprocessor (16); After the centrifuge (14) is dehydrated, the product becomes low-ash coal p, and the filtrate q enters the thickener (22); the under-screen pulp i and the under-screen pulp o pass through the pulp preprocessor (16) for pulping and chemical tank (15) After dosing, it is fed into the flotation column (18) by the feeding pump (17) for flotation, the flotation tailings r enters the concentrator (22), and the flotation concentrate s enters the press filter and enters the barrel (19) through Feeding pump (20) is fed into filter press (21) for pressure filtration and dehydration. After dehydration, filter cake becomes medium ash coal t, and filtrate u enters circulating water pool (25) for circulating water use. 2. a kind of gasification slag fine separation process according to claim 1, is characterized in that, described sieve water g, sieve water m, filtrate q and flotation tailings r enter concentrator (22) to concentrate, The concentrated overflow w enters the circulating water pool (25) for use as circulating water, and the concentrated underflow v is fed into the filter press (24) through the pressure filter feeding pump (23) for dehydration by pressure filtration. After dehydration, the filter cake becomes tailings x, and the filtrate y Enter the circulating water pool (25) and use as circulating water; The circulating water in the circulating pool (25) uses a part of the clear water pump (26) to feed the mixing tank (2), the mixing tank (4) and the mixing tank (9) for pulping, and a part is used as a composite hydrocyclone ( 6), supplementary water for disturbing bed separator (11) and spraying water for screening equipment. 3. A kind of gasification slag fine separation process according to claim 1, is characterized in that, after described desliming, ore pulp i and ore pulp o also can not need flotation, directly enter concentrator (22) to concentrate, after Become tailings after filter press (24) pressure filtration. 4. A gasification slag fine separation process according to claim 1, characterized in that, the separation method finally obtains three products: low-ash coal, medium-ash coal and tailings. 5 . A gasification slag fine separation process according to claim 1 , characterized in that the vibrating screen ( 3 ) is a linear single-layer vibrating screen of ZS type. 6. A gasification slag fine separation process according to claim 1, characterized in that, the diameter of the composite hydrocyclone (6) is 200mm, and the cone angle is selected from a large cone angle of 80°-150°; The diameter of the secondary water inlet hole in the 6 cylindrical section of the composite hydrocyclone is 3 mm, and it is 45° to the tangent. 7. A kind of gasification slag fine separation process according to claim 1, is characterized in that, described dewatering screen (7), dewatering screen (12), desliming screen (8) and desliming screen (13) It is a high frequency vibrating screen. 8 . The gasification slag fine separation process according to claim 1 , characterized in that, the disturbed bed separator ( 11 ) can be selected from TBS or cascade pulse separator with a diameter of 1000 mm. 9. A gasification slag fine separation process according to claim 1, characterized in that the centrifuge (14) is a decanter centrifugal dehydrator. 10. A gasification slag fine separation process according to claim 1, characterized in that the thickener (22) is an optional deep cone thickener or a high-efficiency thickener.

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