CN106635100B - It is a kind of using waste as the coal powder formation method for destructive distillation of adhesive - Google Patents

Abstract

The invention discloses a pulverized coal molding dry distillation method using waste as a binder. The steps are as follows: the coal is crushed and screened to obtain pulverized coal; Coal tar pitch, tar residue, polyaluminum ferric chloride are mixed and fully stirred, and when the mixture is softened, dolomite powder is poured into it and heated and stirred to form a sticky paste to obtain an adhesive; the prepared adhesive is mixed with The mixture compounded with pulverized coal is cold-pressed in a molding die with a pressure of 8-20 MPa to obtain briquettes; the resulting briquettes are pyrolyzed at 500-750°C in a retort furnace for 2-4 hours. Get semi-coke, coal tar, gas. This method provides a feasible way for the production of semi-coke without raw material lump coal, and solves the problem that the tar residue in the factory cannot be effectively used to the greatest extent. The coal tar in the tar residue is eaten and squeezed, and the oil yield of the briquette is improved. Realize the reuse of waste, thereby improving the utilization value of pulverized coal.

Description

A pulverized coal molding dry distillation method using waste as a binder

technical field

The invention relates to the technical field of semi-coke production in coal chemical industry, in particular to a pulverized coal forming dry distillation method using waste as a binder.

Background technique

Semi-coke (semi-coke) is a kind of high-fixed carbon combustible solid material obtained from Jurassic non-sticky and weakly sticky lump coal with a thickness of 30-80 mm, which is obtained by pyrolysis at medium and low temperatures. It has "three highs and four lows" It is a new generation of clean and environmentally friendly fuel. However, as the birthplace and main production area of the national semi-coke industry, after years of development, the semi-coke industry has become the largest coal chemical industry and an important local economic pillar in Yulin City, but with the continuous improvement of mechanization, coal mining The method has changed from blast mining to fully mechanized mining, and the semi-coke industry has a serious shortage of raw material lump coal (reduced from the original 30% to less than 10%). In terms of pulverized coal dry distillation, there are currently several projects in Yulin City that are undergoing pilot tests, such as the externally heated rotary furnace jointly developed by Yushen Jinhua Energy Technology Co., Ltd. and Chang'an University, and the externally heated rotary furnace developed by Shenmu Tianyuan Chemical Company. However, no suitable solutions have been found for the common problems in pulverized coal pyrolysis, such as gas-solid separation, coke powder bonding, and sealing of rotary equipment. In addition, raw coal produces semi-coke, gas and coal tar during the medium-low temperature carbonization process, and the yield of coal tar as a product is low (7-8%). Among them, semi-coke can be used as raw materials for downstream metallurgical calcium carbide and other industries, and gas is used Dolomite is calcined to obtain dolomite powder, and coal tar is fractionated to obtain light coal tar, heavy coal tar and tar residue, and heavy coal tar is flashed to obtain light coal tar and heavy tar pitch. Due to the low utilization value of pulverized coal, fly ash is produced after it is sent to power plants for power generation. The waste residues such as tar residue, heavy coal tar pitch and fly ash produced in the above process will seriously pollute the environment if they are directly discarded. Tar residue and heavy coal tar contain a large amount of carcinogens, pollute water bodies and soil, and seriously Threat to human health; due to its tiny particles, fly ash is exposed to pollute the atmosphere in the air, and is the chief culprit of smog weather.

Contents of the invention

In order to solve the above problems, the present invention provides a pulverized coal molding carbonization method using waste as a binder, using the waste obtained after coal pyrolysis at medium and low temperatures to make a binder and compound it with pulverized coal, and design a It is a semi-coke production process with the characteristics of clean combustion, high calorific value, low ash, high oil yield and high strength.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A pulverized coal forming dry distillation method using waste as a binder, comprising the following steps:

(1) The coal is crushed and screened to obtain pulverized coal;

(2) Raise the water to 80-100°C, mix heavy coal tar pitch, tar residue, polyaluminum ferric chloride in sequence and stir well, when the mixture softens, pour dolomite powder and heat and stir to make a thick paste Like substance, obtain adhesive;

(3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture;

(4) cold pressing the mixture of step (3) in a molding die to obtain briquettes;

(5) Carrying out the medium-low temperature pyrolysis for 2-4 hours at 500-750 DEG C in a carbonization furnace with the briquette product obtained in step (4) to obtain briquette, coal tar and coal gas;

The mass percentage of each raw material is as follows: 50-65% of pulverized coal below 1 mm, 5-20% of pulverized coal of 1-3 mm, 5-10% of water, 5%-15% of tar residue, 5% of heavy coal tar pitch %~10%, dolomite powder 1%~3%, polyaluminum ferric chloride 0.5%~2.0%.

Preferably: the tar residue and heavy coal tar pitch in the step (2) are produced after fractionation of coal tar. Advantages: It enables comprehensive utilization of waste and improves the strength of coal briquettes.

Preferably: the dolomite powder in the step (2) is produced by calcining dolomite with gas. Advantages: The main component is CaMg[CO ₃ ] ₂ , which is a carbonate mineral in the trigonal crystal system. Mixing it into pulverized coal can improve the stability of the briquette, thereby obtaining high-strength semi-coke.

Preferably: the pressure in the step (4) is 10-20MPa.

Preferably: the coal in the step (1) is non-caking coal or weakly caking coal.

Preferably: the polyaluminum ferric chloride in the step (2) is obtained by dissolving fly ash in acid and alkali. Advantages: Mixed into pulverized coal to play a catalytic role, thus improving the oil yield of coal briquettes.

Preferably: the dry distillation furnace in the step (5) is a vertical dry distillation furnace.

Preferably: the strength of the coal briquettes in the step (4) is 1250-2568N/ball.

Preferably: the strength of the medium-sized semi-coke product in the step (5) is 1000-1800 N/ball.

The second object of the present invention is to provide a kind of briquette, briquette, coal tar or coal gas prepared by any one of the above methods.

The beneficial effects of the present invention are:

Starting from the recycling industry chain, give full play to the advantages of downstream industries such as gas, coal tar and pulverized coal thermal power generated in the process of medium and low temperature dry distillation, and use the dolomite powder produced by gas calcining dolomite, heavy coal tar pitch obtained by separating coal tar, A large amount of solid waste such as tar slag is used as the main binder to bind pulverized coal, and the polyaluminum ferric chloride produced with the fly ash produced in the thermal power generation process as raw material is formed into dry distillation, in order to improve the carbonization efficiency through catalytic pyrolysis. The oil yield rate of the process enables pulverized coal to be produced in the vertical carbonization furnace of the original semi-coke industry, expands the industrial chain, and realizes economic green and sustainable development.

Tar residue and heavy coal tar contain a large amount of coal tar (25-35%) and have good viscosity; fly ash contains a large amount of silicon, aluminum and iron elements, which are polymerized after chemical treatment (acid dipping and alkali dissolution) Aluminum iron chloride inorganic polymer. Therefore, fully mix tar residue, heavy coal tar, fly ash and a small amount of dolomite powder in a certain amount of tap water to obtain a self-made adhesive, mix it into pulverized coal and form it by cold pressing to obtain High-strength lump coal, so as to realize the conversion of powder coal to lump coal, provide raw materials and technical feasibility for the production of semi-coke, realize resource recycling and tar residue, heavy coal tar pitch and pulverized coal Reuse of ashes and other waste residues. Therefore, it has brought huge economic benefits to enterprises, achieved green and sustainable economic development, and can expand the industrial chain, which is of great significance to the development of my country's coal industry.

In the present invention, non-caking coal or weakly caking coal is mixed with a variety of waste self-made binders to prepare briquettes and semi-coal, gas and coal tar are produced in the process of low-temperature dry distillation of briquettes, among which semi-coke can be used as downstream metallurgy The raw material of calcium carbide and other industries, coal gas is used to calcinate dolomite to obtain dolomite powder, coal tar is fractionated to obtain light coal tar, heavy coal tar and tar residue, and heavy coal tar is flashed to obtain three kinds of light coal tar And heavy tar pitch, the use value of pulverized coal is low, and the fly ash is obtained after being transported to the power plant for power generation. The fly ash contains a large amount of silicon, aluminum and iron elements, and the polyaluminum ferric chloride is obtained after acid leaching and alkali dissolution. The above-mentioned heavy tar pitch, tar residue, polyaluminum ferric chloride and dolomite powder are co-heated and mixed with tap water but in a specific ratio to obtain a self-made adhesive, mixed into pulverized coal, and then cold-pressed to make briquettes. After the coal undergoes medium and low temperature dry distillation, semi-coke, coal tar and gas will be obtained, so as to realize the recycling of resources and the reuse of waste tar residue and fly ash. This method provides a feasible way for the production of semi-coke without raw material lump coal, and solves the problem that the tar residue in the factory cannot be effectively utilized to the greatest extent, and the coal tar in the tar residue is dried and squeezed to improve the oil yield of the briquette. Realize the reuse of waste, thereby improving the utilization value of pulverized coal. This process has the characteristics of simple process, low cost, reuse of waste, and conforms to the characteristics of green circular economy.

Description of drawings

Fig. 1 is the process flow chart of embodiment 1.

Detailed ways

In order to better understand the technical solution of the present invention, the present invention will be further described below in conjunction with the examples.

The raw materials used in the examples are pulverized coal produced by the Hanglai Bay Coal Mine of Shaanxi Nonferrous Yulin Coal Industry Co., Ltd. and tar slag produced by the semi-coke plant of Shenmu Sihai Coal Chemical Co., Ltd. The industrial analysis of raw coal is shown in Table 1.

Table 1:

In the table: Mt is the total moisture, Aad is the ash content on the air-drying basis, FCad is the fixed carbon on the air-drying basis, and Vad is the volatile matter on the air-drying basis.

Example 1:

As shown in Figure 1, a kind of pulverized coal forming dry distillation method using waste as binder comprises the following steps:

(1) The coal is crushed and screened to obtain pulverized coal;

(2) Raise the temperature of the water to 80°C. At this temperature, mix heavy coal tar pitch, tar residue, and polyaluminum ferric chloride in sequence and stir well. When the mixture softens, pour dolomite powder into it and heat and stir. Make a viscous pasty substance to obtain a binder;

(3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture;

(4) The mixture of step (3) is cold-pressed with 10MPa pressure in a molding die to obtain briquettes;

(5) Pyrolyzing the briquette product obtained in step (4) at 500° C. for 4 hours in a retort furnace to obtain briquette, coal tar and gas.

According to the percentage by weight, mix 5% of tar residue, 5% of heavy coal tar pitch, 1% of dolomite powder, 0.5% of polyaluminum ferric chloride, 65% of pulverized coal below 1 mm, and 1-3 mm of powder Coal 18.5%, 5% water. Table 2 shows the performance analysis of briquettes and the briquettes obtained after dry distillation of briquettes, coal tar and gas.

Table 2:

In the table: Qgr,d is the high calorific value on a dry basis.

Example 2:

A pulverized coal forming dry distillation method using waste as a binder, comprising the following steps:

(1) The coal is crushed and screened to obtain pulverized coal;

(2) Raise the temperature of the water to 100°C. At this temperature, mix heavy coal tar pitch, tar residue, and polyaluminum ferric chloride in sequence and stir well. When the mixture softens, pour dolomite powder into it and heat and stir. Make a viscous pasty substance to obtain a binder;

(3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture;

(4) the mixture of step (3) is cold-pressed with 18MPa pressure in the molding die to obtain briquettes;

(5) Pyrolyzing the briquette product obtained in step (4) at 600° C. for 3 hours in a retort furnace to obtain briquette, coal tar and gas.

The coal blending ratio is shown in Table 3.

table 3:

Table 4 shows the performance analysis of the briquettes and the briquettes, coal tar, and gas obtained after dry distillation of the briquettes.

Table 4:

Example 3:

A pulverized coal forming dry distillation method using waste as a binder, comprising the following steps:

(1) The coal is crushed and screened to obtain pulverized coal;

(2) Raise the temperature of the water to 90°C. At this temperature, mix the heavy coal tar pitch, tar residue, and polyaluminum ferric chloride in sequence and stir well. When the mixture softens, pour in dolomite powder and heat and stir. Make a viscous pasty substance to obtain a binder;

(3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture;

(4) the mixture of step (3) is cold-pressed with 20MPa pressure in the molding die to obtain briquettes;

(5) Pyrolyzing the briquette product obtained in step (4) at 750° C. for 24 hours in a retort furnace to obtain briquette, coal tar and gas.

The coal blending ratio is shown in Table 5.

table 5:

Table 6 shows the performance analysis of briquettes and the briquettes obtained after dry distillation of briquettes, coal tar and gas.

Table 6

Example 4:

A pulverized coal forming dry distillation method using waste as a binder, comprising the following steps:

(1) The coal is crushed and screened to obtain pulverized coal;

(2) Raise the temperature of the water to 80-100°C. At this temperature, mix the heavy coal tar pitch, tar residue, and polyaluminum ferric chloride in sequence and stir well. When the mixture softens, pour in the dolomite powder Heat and stir to make a sticky paste to obtain a binder;

(3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture;

(4) the mixture of step (3) is cold-pressed to obtain briquettes with 15MPa pressure in molding die;

(5) Pyrolyzing the molded coal product obtained in step (4) at 650° C. for 4 hours in a retort furnace to obtain molded semi-coal, coal tar and gas.

The coal blending ratio is shown in Table 7.

Table 7:

Table 8 shows the performance analysis of briquettes and the briquettes obtained after dry distillation of briquettes, coal tar and gas.

Table 8:

In Example 4, due to the excessive use of each component of the binder, the compressive strength of the semi-coke does not exceed 600N/ball, and the ash and volatile matter are relatively large, which cannot reach the standard of the semi-coke.

Although the technical solution formula of the present invention has been described in conjunction with the embodiments, it is not intended to limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work. Various modifications or variations can be made within the protection scope of the present invention.

Claims (10)

1. A pulverized coal forming dry distillation method using waste as a binding agent is characterized in that: comprising the following steps: (1) The coal is crushed and screened to obtain pulverized coal; (2) Raise the temperature of the water to 80-100°C. At this temperature, mix the heavy coal tar pitch, tar residue, and polyaluminum ferric chloride in sequence and stir well. When the mixture softens, pour in the dolomite powder Heat and stir to make a sticky paste to obtain a binder; (3) Compounding the binder prepared in step (2) with the pulverized coal in step (1) and fully mixing to obtain a mixture; (4) cold pressing the mixture of step (3) in a molding die to obtain briquettes; (5) Carrying out the medium-low temperature pyrolysis for 2-4 hours at 500-750 DEG C in a carbonization furnace with the briquette product obtained in step (4) to obtain briquette, coal tar and coal gas; The mass percentage of each raw material is as follows: 50-65% of pulverized coal below 1 mm, 5-20% of pulverized coal of 1-3 mm, 5-10% of water, 5%-15% of tar residue, 5% of heavy coal tar pitch %~10%, dolomite powder 1%~3%, polyaluminum ferric chloride 0.5%~2.0%. 2. The method according to claim 1, characterized in that: the coal in the step (1) is non-caking coal or weakly caking coal. 3. The method according to claim 1, characterized in that: the tar residue and heavy coal tar pitch in the step (2) are produced after fractionation of coal tar. 4. The method according to claim 1, characterized in that: the dolomite powder in the step (2) is produced by coal gas calcined dolomite. 5. The method according to claim 1, characterized in that: the polyaluminum ferric chloride in the step (2) is obtained by dissolving fly ash through acid dipping and alkali dissolution. 6. The method according to claim 1, characterized in that: the pressure in the step (4) is 10-20MPa. 7. The method according to claim 1, characterized in that: the strength of the briquette in the step (4) is 1250～2568N/ball 8. The method according to claim 1, characterized in that: the retort furnace in the step (5) is a vertical retort furnace. 9. The method according to claim 1, characterized in that: the strength of the medium-sized semi-coke product in step (5) is 1000-1800N/ball. 10. the molded coal, molded semi-coke, coal tar or coal gas that the arbitrary described method of claim 1-9 prepares.