CN110467953A - The method for producing clean formed coke based on waterglass transition state binder - Google Patents

Abstract

A method for producing clean coke based on a water glass transition state binder, the method is to select kaolin, silica, limestone and coal liquefaction residue, break them separately, then add water glass powder and pregelatinized starch, and mix evenly through stirring , and then through dry grinding to obtain the alumina transition state binder; select the blended coal, and mix the blended coal and the water glass transition state binder in proportion, cold press molding, dry distillation at high temperature, and then reduce to At room temperature, clean coke can be obtained; the source of raw materials in the invention is wide and abundant, and the price is low. It acts as a bond before it acts, ensuring the molding rate and coke strength of the material in the retort furnace.

Description

Method for producing clean coke based on water glass transition state binder

technical field

The invention relates to a method for producing clean coke, in particular to a method for producing clean coke by using a water glass transition state binder.

Background technique

In some special primary energy endowments that are rich in coal, poor in oil and little in gas, coal combustion is the main way to obtain energy, but the dust, sulfur dioxide, nitrogen oxides, etc. emitted by the direct combustion of a large amount of coal have caused serious harm to the atmospheric environment. Leading to serious air pollution and frequent occurrence of smog. For example, in 2014, China's statistics for civilian coal consumption was 160 million tons, accounting for only 3.8% of the country's coal consumption. Taking sulfur dioxide emissions as an example, the annual emissions of power plants are 200 10,000 tons, and civil scattered combustion is as high as 3.2 million tons, which is 1.6 times the total emissions of power plants. In addition, a series of problems such as soot pollution, nitrogen oxide pollution, and ash pollution of coal used for civil scattered combustion are even more damaging to the ecological environment. It is immeasurable. However, due to the influence of geographical, economic, cultural and other factors, it is very difficult to solve. In order to fundamentally solve the problem of coal burning pollution in rural areas and small towns, provide these areas with high-quality, low-cost, clean alternative fuels It is imperative.

Moreover, thermal coal used as fuel is mainly low-rank coal. With the improvement of coal mining mechanization, the proportion of fine coal in the mining process is increasing, and how to efficiently utilize fine coal has received more and more attention.

Clean coke is a kind of low-rank fine coal, supplemented by a small amount of sulfur-fixing agent, combustion improver, binder, etc., which is obtained by medium-temperature dry distillation after preforming using the existing semi-coke plant production equipment. Clean solid fuel has the advantages of high molding rate, good strength, low volatilization, low sulfur emission, and not easy to slagging. No desulfurization facilities are required, and the exhaust gas can meet the national emission standards; and it is easy to ignite, has a strong ability to continue the fire, and has a fast heating rate. The combustion lasts for a long time, and it is an ideal fuel for various domestic stoves.

Existing pulverized coal forming carbonization method has fewer patents, such as the coal liquefaction residue used in CN106635217A as its cold and hot state binder, directly mixed with pulverized coal and then carbonized; Dry distillation after mixing with pulverized coal as a binder to obtain molded coke; the publication number is CN106753496A, which uses tar residue as the base binder, supplemented by cornmeal and inorganic magnesium salt, and then dry distillation; the publication number is CN106929063A. Heavy coal tar pitch, tar residue, polyaluminum ferric chloride are mixed and softened by heating, then dolomite powder is added to obtain a binder, and mixed with pulverized coal, the coal is cold pressed to form coal, and then dry distillation is obtained to form coke. The binders used in these patented coke formulations are mainly used in the cold forming process below 200°C and the hot binder in the dry distillation process above 400°C, but the actual dry distillation process There is a stage where the cold binder fails between 200-400°C and the hot binder does not work. Due to the lack of use of transition binders in this temperature range, the coke breakage rate is high during the carbonization process. .

After retrieval, there is no report on the water glass transition state binder used to produce clean coke.

Contents of the invention

The specific technical problem to be solved by the present invention is that the binder used for clean coke production has a stage where the binder in the cold state fails between 200-400°C and the binder in the hot state does not function during the retort process. The use of the transition state binder in this temperature range leads to a high coke breakage rate in the dry distillation process. In order to solve this problem, the present invention provides a method for producing clean coke based on a water glass transition state binder.

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

A method for producing clean coke based on a water glass transition state binder, characterized in that: the method for producing clean coke is carried out according to the following steps:

(1) Select the raw material composition and quality index of water glass transition state binder as water glass powder, soluble solids ≥ 95wt%, kaolin SiO ₂ ≥ 50wt%, silica SiO ₂ ≥ 96wt%, pregelatinized starch: viscosity ≥ 600mPa .s, limestone CaO≥51wt% and coal liquefaction residue: residual oil + asphaltenes≥60wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 5-10 parts of broken kaolin, 5-10 parts of silica, 10-20 parts of limestone and 50-60 parts of coal liquefaction residue by weight, and weigh 20-30 parts of water glass powder and pregelatinized starch 10-20 parts, mix them together one by one, stir and mix evenly;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf ≥ 25%, dry basis ash A _d ≤ 15%, dry basis fixed carbon FC _d ≥ 55%, dry basis total sulfur S _t,d <1.5%;

⑹ The weight ratio of water glass transition state binder to blended coal is 10-30:100. After the blended coal is crushed to -3mm, it is mixed evenly with the water glass transition state binder. First, it is formed by cold pressing, and the forming pressure is selected to be 10. -15MPa, under this molding pressure, the strength of the briquette meets >800N/ball. The prepared briquette is dry-distilled in a vertical retort furnace at a temperature of 600-900°C for 2-4 hours, and then the red-hot charge After being released from the furnace, it is cooled to normal temperature through the coke quenching process to obtain clean coke.

The strength index of clean coke mentioned therein: compressive strength 800N/ball-2000N/ball, molding rate > 80%, final rate < 10%.

In the above technical scheme, the present invention combines water glass with coal direct liquefaction residue, limestone and starch to produce clean type coke, and its function is mainly manifested in the triple function of cold state, hot state and transition state binder , the traditional form coke binder only considers the hot and cold state binder, and does not consider that the cold state starch binder will fail in the temperature range of 200-400°C during the form coke carbonization process after the powder coal is formed. The ineffective transition time of the hot state binder is the stage where the coke is most likely to be broken at this time stage; the innovation of the present invention is to provide a kind of water glass transition state binder for use, which can be used at 200 The action continues to occur in the temperature range of -400°C. The mechanism of action is that after the water glass and coal particles are stirred and mixed, the surface of the coal particles is covered with a layer of water glass film, and the adjacent coal particles are connected by the adhesive film. Dehydration and hardening are achieved during the process. When the temperature rises to 80°C, the water molecules rearrange and catalyze the condensation between adjacent silanol groups, and when further heated to above 120-130°C, the remaining water molecules promote the silanol The condensation of groups, and the dehydration and association between Si-OH bonds form Si-O-Si bonds, which is a three-dimensional solidification system with excellent water resistance. Na and H are in the closed state of the three-dimensional structure film, and are insoluble in water. When the curing temperature rises above 200°C, a curing system with excellent water resistance can be obtained, thereby avoiding pressure and The breakage of clean coke caused by self-expansion or compression.

The above-mentioned method for producing clean coke based on water glass transition state binder provided by the present invention, compared with the prior art, the source of raw materials used in the present invention is wide and abundant, the price is low, and it has both hot and cold state bonding In the pyrolysis process, the cold binder fails and the hot binder acts before the hot binder takes effect, ensuring the molding rate and coke strength of the material in the retort furnace.

The invention realizes high-efficiency utilization of low-order fine coal and improves the utilization value of fine coal.

Detailed ways

The specific implementation manners of the present invention will be further described below.

Example 1

Implement a kind of method that the above-mentioned provided of the present invention is based on water glass transition state binding agent and produce clean type coke, concrete implementation method is as follows:

(1) Select the raw material composition and quality index of the water glass transition state binder as water glass powder, soluble solids 99wt%, kaolin SiO ₂ 50wt%, silica SiO ₂ 96wt%, pregelatinized starch: viscosity 1000mPa.s, limestone CaO56wt% and coal liquefaction residue: residual oil + asphaltene 80wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 10 kg of crushed kaolin, 20 kg of silica, 20 kg of limestone and 50 kg of coal liquefaction residue in parts by weight, and weigh 20 kg of water glass powder and 10 kg of pregelatinized starch, mix them together in turn, and mix them evenly through stirring;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf 30.0wt%, dry basis ash A _d 13.5wt%, dry basis fixed carbon FC _d 59.1wt%, dry basis total sulfur S _t,d 1.46wt%;

⑹ The weight ratio of water glass transition state binder to blended coal is 10:100. After the blended coal is crushed to -3mm, it is evenly mixed with water glass transition state binder. The prepared briquettes are dry-distilled in a vertical carbonization furnace at a temperature of 900°C for 2 hours, and then the red-hot charge is taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain clean molded coke.

Comparative example 1

The coal used in the furnace is the same blended coal without adding water glass transition state binder. The blended coal is crushed to -3mm and mixed with the binder evenly. The briquette was carbonized in a vertical carbonization furnace at a temperature of 900°C for 2 hours, and then the red-hot charge was taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain coke for reference.

The compressive strength, forming rate and final rate of the obtained clean coke and reference coke were measured in Jinan Zhongluchang YAW-300D strength tester and Xinxiang Chenwei YBS-1000 sieving machine respectively. The test results are as follows Table 1 shows.

Table 1 Comparison of compressive strength, forming rate and final rate index

Example 2

Implement a kind of method that the above-mentioned provided of the present invention is based on water glass transition state binder and produce clean type coke, concrete implementation is as follows:

(1) Select the raw material composition and quality index of the water glass transition state binder as water glass powder, soluble solids 98wt%, kaolin SiO ₂ 55wt%, silica SiO ₂ 96.6wt%, pregelatinized starch: viscosity 900mPa.s, Limestone CaO54wt% and coal liquefaction residue: residual oil + asphaltene 75wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 9kg of crushed kaolin, 16kg of silica, 17.5kg of limestone and 52.5kg of coal liquefaction residue in parts by weight, and weigh 22.5kg of water glass powder and 12.5kg of pregelatinized starch, mix them together in turn, and mix them by stirring Uniform;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf 29.0wt%, dry basis ash A _d 12.4wt%, dry basis fixed carbon FC _d 61.2wt%, dry basis total sulfur S _t,d 0.97wt%;

⑹ The weight ratio of water glass transition state binder to blended coal is 15:100. After the blended coal is crushed to -3mm, it is evenly mixed with water glass transition state binder. The prepared briquettes are dry-distilled in a vertical carbonization furnace at a temperature of 850°C for 2.5 hours. After the red-hot charge is discharged from the furnace, it is cooled to normal temperature through a coke quenching process to obtain clean molded coke.

Comparative example 1

The coal used in the furnace is the same blended coal without adding water glass transition state binder. The blended coal is crushed to -3mm and mixed with the binder evenly. Coal briquettes were dry-distilled in a vertical carbonization furnace at a temperature of 850°C for 2.5 hours, and then the red-hot charge was taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain coke for reference.

The compressive strength, forming rate and final rate of the obtained clean coke and reference coke were measured in Jinan Zhongluchang YAW-300D strength tester and Xinxiang Chenwei YBS-1000 sieving machine respectively. The test results are as follows Table 2 shows.

Table 2 Comparison of compressive strength, forming rate and final rate index

sample Compressive strength (N/ball) Molding rate/% Final rate/% contrast focus 760 73.2 16.8 Clean coke with transition state binder added 920 82.5 9.1

Example 3

Implement a kind of method that the above-mentioned provided of the present invention is based on water glass transition state binder and produce clean type coke, concrete implementation is as follows:

(1) Select the raw material composition and quality index of the water glass transition state binder as water glass powder, soluble solids 97wt%, kaolin SiO ₂ 60wt%, silica SiO ₂ 97.2wt%, pregelatinized starch: viscosity 800mPa.s, Limestone CaO53wt% and coal liquefaction residue: residual oil + asphaltene 70wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 8 kg of crushed kaolin, 12 kg of silica, 15 kg of limestone, and 55 kg of coal liquefaction residue in parts by weight, and weigh 25 kg of water glass powder and 15 kg of pregelatinized starch, mix them together successively, and mix them evenly through stirring;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf 32.0wt%, dry basis ash A _d 11.7wt%, dry basis fixed carbon FC _d 59.2wt%, dry basis total sulfur S _t,d 0.84wt%;

⑹ The weight ratio of water glass transition state binder to blended coal is 20:100. The mixed coal is crushed to -3mm and mixed evenly with the water glass transition state binder. The prepared briquettes are dry-distilled in a vertical carbonization furnace at a temperature of 800°C for 3 hours, and then the red-hot charge is taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain clean molded coke.

Comparative example 3

The coal into the furnace adopts the same blended coal without adding water glass transition state binder. The blended coal is crushed to -3mm and mixed with the binder evenly. Coal briquettes were dry-distilled in a vertical carbonization furnace at a temperature of 800°C for 3 hours, and then the red-hot charge was taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain coke for reference.

The compressive strength, forming rate and final rate of the obtained clean coke and reference coke were measured in Jinan Zhongluchang YAW-300D strength tester and Xinxiang Chenwei YBS-1000 sieving machine respectively. The test results are as follows Table 3 shows.

Table 3 Comparison of compressive strength, forming rate and final rate index

sample Compressive strength (N/ball) Molding rate/% Final rate/% contrast focus 840 76.3 15.1 Clean coke with transition state binder added 1180 89.1 7.8

Example 4

Implement a kind of method that the above-mentioned provided of the present invention is based on water glass transition state binder and produce clean type coke, concrete implementation is as follows:

(1) Select the raw material composition and quality index of water glass transition state binder as water glass powder, soluble solids 96wt%, kaolin SiO ₂ 65wt%, silica SiO ₂ 97.8wt%, pregelatinized starch: viscosity 700mPa.s, Limestone CaO52wt% and coal liquefaction residue: residual oil + asphaltene 65wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 7kg of crushed kaolin, 8kg of silica, 12.5kg of limestone and 57.5kg of coal liquefaction residue in parts by weight, and weigh 27.5kg of water glass powder and 17.5kg of pregelatinized starch, mix them together in turn, and mix them by stirring Uniform;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf 25.0wt%, dry basis ash A _d 14.1wt%, dry basis fixed carbon FC _d 63.2wt%, dry basis total sulfur S _t,d 1.23wt%;

⑹ The weight ratio of water glass transition state binder to blended coal is 25:100. After the blended coal is crushed to -3mm, it is evenly mixed with water glass transition state binder. The prepared briquettes are dry-distilled in a vertical carbonization furnace at a temperature of 700°C for 3.5 hours, and then the red-hot charge is taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain clean molded coke.

Comparative example 4

The coal used in the furnace is the same blended coal without adding water glass transition state binder. The blended coal is crushed to -3mm and mixed with the binder evenly. Coal briquettes were dry-distilled in a vertical carbonization furnace at a temperature of 700°C for 3.5 hours, and then the red-hot charge was taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain coke for reference.

The compressive strength, forming rate and final rate of the obtained clean coke and reference coke were measured in Jinan Zhongluchang YAW-300D strength tester and Xinxiang Chenwei YBS-1000 sieving machine respectively. The test results are as follows Table 4 shows.

Table 4 Comparison of compressive strength, forming rate and final rate index

sample Compressive strength (N/ball) Molding rate/% Final rate/% contrast focus 830 75.6 15.8 Clean coke with transition state binder added 1105 87.7 8.1

Example 5

Implement a kind of method that the above-mentioned provided of the present invention is based on water glass transition state binder and produce clean type coke, concrete implementation is as follows:

(1) Select the raw material composition and quality index of water glass transition state binder as water glass powder, soluble solids 95wt%, kaolin SiO ₂ 70wt%, silica SiO ₂ 98.5wt%, pregelatinized starch: viscosity 600mPa.s, Limestone CaO51wt% and coal liquefaction residue: residual oil + asphaltene 60wt%;

⑵Crush the raw materials of water glass transition state binder, kaolin, silica, limestone and coal liquefaction residue, respectively to particle size ≤ 3mm; water glass powder and pregelatinized starch are used for later use;

(3) Weigh 5 kg of crushed kaolin, 5 kg of silica, 10 kg of limestone, and 60 kg of coal liquefaction residue in parts by weight, and weigh 30 kg of water glass powder and 20 kg of pregelatinized starch, mix them together in turn, and mix them evenly through stirring;

(4) The mixture is then dry-ground to make the particle size of the raw material ≤ 100 mesh, which is the water glass transition state binder;

⑸ Select the furnace dust coal as blending coal, and its quality indicators are: dry ash-free basis volatile V _daf 34.0wt%, dry basis ash A _d 15.0wt%, dry basis fixed carbon FC _d 55.4wt%, dry basis total sulfur S _t,d 0.70wt%;

⑹ The weight ratio of water glass transition state binder to blended coal is 30:100. The mixed coal is crushed to -3mm and mixed evenly with the water glass transition state binder. The prepared briquettes are dry-distilled in a vertical carbonization furnace at a temperature of 600°C for 4 hours, and then the red-hot charge is taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain clean molded coke.

Comparative example 5

The coal used in the furnace is the same blended coal without adding water glass transition state binder. The blended coal is crushed to -3mm and mixed with the binder evenly. Coal briquettes were dry-distilled in a vertical retort furnace at a temperature of 600°C for 4 hours, and then the red-hot charge was taken out of the furnace and then cooled to normal temperature through a coke quenching process to obtain coke for reference.

The compressive strength, forming rate and final rate of the obtained clean coke and reference coke were measured in Jinan Zhongluchang YAW-300D strength tester and Xinxiang Chenwei YBS-1000 sieving machine respectively. The test results are as follows Table 5 shows.

Table 5 Comparison of compressive strength, forming rate and final rate index

sample Compressive strength (N/ball) >30mm <10mm contrast focus 810 75.1 15.5 Clean coke with transition state binder added 1052 85.6 8.6

Claims (2)

1. a kind of method for producing clean formed coke based on waterglass transition state binder, it is characterised in that: the production lustration type Burnt method follows these steps to carry out:

Choose waterglass transition state binder raw material composition and its quality index be waterglass powder, soluble solids >=95wt%, Kaolin SiO₂>=50wt%, silica SiO₂>=96wt%, pre-gelatinized starch: viscosity >=600mPa.s, lime stone CaO >=51wt% with And coal liquefaction residue: Residual oil+asphaltene >=60wt%；

(2), by the feed kaolin of waterglass transition state binder, silica, lime stone and coal liquefaction residue, grain is crushed to respectively Degree≤3mm, waterglass powder and pre-gelatinized starch are spare；

(3) weigh 10-20 parts of 5-10 parts of 5-10 parts of kaolin, silica, lime stone being crushed by weight respectively and coal liquefaction is residual 50-60 parts of slag, 20-30 parts of waterglass powder and 10-20 parts of pre-gelatinized starch are separately weighed, are successively mixed, it is agitated mixed It closes uniform；

(4) mixture makes raw material granularity≤100 mesh, as waterglass transition state binder again through dry grinding；

(5) choosing into furnace smalls is mixed coal, quality index are as follows: dry ash free basis volatile matter V_daf>=25%, dry basis ash content A_d≤ 15%, butt fixed carbon FC_d>=55%, the full sulphur S of butt_t,d< 1.5%；

(6) the weight ratio of waterglass transition state binder and mixed coal is 10-30: 100, and mixed coal is crushed to after -3mm and water Glass transition state binder is uniformly mixed, and first through cold moudling, briquetting pressure selects 10-15MPa, the moulded coal under the briquetting pressure Intensity meets > 800N/ball, by moulded coal obtained 600-900 DEG C at a temperature of, through vertical type gas retort destructive distillation, when destructive distillation Long 2-4h is down to room temperature through quenching process after then red heat furnace charge is come out of the stove to get clean formed coke is arrived.

2. the method for producing clean formed coke based on waterglass transition state binder as described in claim 1, it is characterised in that: institute State the intensity index of clean formed coke: compression strength 800N/ball-2000N/ball, ratio of briquetting > 80%, last rate < 10%.