CN114540091A

CN114540091A - Powdered coal forming method for solving long-distance transportation problem of low-rank bituminous coal

Info

Publication number: CN114540091A
Application number: CN202210085027.XA
Authority: CN
Inventors: 张秋民; 杨婉莹; 何德民; 关珺
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2022-05-27

Abstract

The invention belongs to the technical field of railway transportation, and discloses a pulverized coal forming method for solving the problem of long-distance transportation of low-deterioration bituminous coal, which comprises the steps of crushing low-deterioration non-stick coal with the particle size of more than 3mm, screening and drying; the low-deterioration non-sticky coal, the hydroxypropyl methyl cellulose and the water are uniformly mixed according to a certain proportion, and then the mixture is pressed and molded in a mold to obtain the molded coal product. The forming method of the low-deterioration non-sticky coal can thoroughly solve the problem that the pulverized coal scatters and raises dust during long-distance transportation, loading and unloading of the low-deterioration pulverized coal, simultaneously overcomes the problems of multiple types and large addition amount of additives in the use process of the dust suppressant, and has the characteristics of good quality and high mechanical strength of the obtained non-sticky coal product.

Description

Powdered coal forming method for solving long-distance transportation problem of low-rank bituminous coal

Technical Field

The invention belongs to the technical field of railway transportation, and particularly relates to a pulverized coal forming method for solving the problem of long-distance transportation of low-rank bituminous coal.

Background

The natural characteristics of energy resources in China are rich coal, lack of oil and little gas, low-rank coal in the reserves of the coal resources accounts for more than 55% of the total amount of the coal resources in China, and is mainly distributed in northwest areas such as Xinxin of Shanshan, while the middle, east and south areas in China are still main consumption areas of the coal. At present, China forms a transportation pattern of transporting western coal from east to south and transporting north coal, long-distance transportation becomes a normal state, and coal transportation by railways is a main transportation mode.

With the application of mechanized mining technology, the lump coal yield decreases year by year and is less than 20%, while the pulverized coal yield increases day by day. The large amount of pulverized coal brings difficulties to the coal storage and transportation process: on one hand, the pulverized coal is continuously overstocked due to the fact that the pulverized coal cannot be effectively utilized for a long time, and serious resource waste is caused; on the other hand, open cars are generally adopted for transportation in the railway long-distance transportation process, and coal dust and coal particles on the surface layer are scattered under the conditions of bumping of trains and high wind speed and negative pressure during meeting of trains, so that economic loss and environmental pollution are caused, the running safety coefficient of the trains is reduced, and great harm is caused.

At present, the main methods for solving the problem of scattering of the pulverized coal include a container, a tarpaulin covering method, a watering method and a dust suppressant spraying method. Wherein the container method has higher cost and unsafe transportation process; the method for covering the tarpaulin is time-consuming and labor-consuming and is easy to blow open by wind; the sprinkling method needs repeated sprinkling and water evaporation, resulting in poor effect; the most commonly used method for spraying the dust suppressant in China has the problems of complex formula, higher cost, stirring before spraying, consumption of a large amount of time, poor adaptability to seasons, air temperature and the like, poor crusting strength and easy shattering, and frequent inspection is required during storage in order to prevent the dust suppressant from losing efficacy and deteriorating. Most importantly, all the methods cannot thoroughly solve the problems of poor limitation of ultra-long distance transportation of the pulverized coal and dust scattering and flying of the pulverized coal during loading and unloading, and along with the gradual increase of the national requirements on environmental protection, the coal chemical industry park has strict requirements on the loading and unloading of the pulverized coal, so that the invention needs to invent a method capable of thoroughly solving the problems.

Disclosure of Invention

The invention aims to provide a pulverized coal forming method, which aims to solve the problem of long-distance transportation of low-deterioration pulverized coal and is particularly suitable for non-caking coal with caking property of 0. The invention has the characteristics of simple process, normal temperature forming, high forming speed and high forming rate, compared with the dust suppressant used in the market at present, the binder adopted by the invention has single type, no need of pretreatment, less dosage, environmental protection and easy degradation, the obtained coal-non-stick shaped coal product has good quality and high mechanical strength, and the problems of poor limitation of ultra-long distance transportation of the pulverized coal and dust scattering and flying of the pulverized coal during loading and unloading can be thoroughly solved.

The technical scheme of the invention is as follows:

a pulverized coal forming method for solving the problem of long-distance transportation of low-rank bituminous coal comprises the following steps:

(1) crushing low-deterioration non-sticky coal with the particle size of more than 3mm, screening and drying;

(2) taking 85-90 wt% of low-deterioration non-sticky coal, 1-6 wt% of hydroxypropyl methyl cellulose and 9 wt% of water, uniformly mixing to form a mixture, and pressing and molding in a molding die to obtain the molded coal.

And (2) drying the low-metamorphic non-sticky coal in the step (1) for 4 hours in a forced air drying oven at 39 ℃.

And (3) adding the low-deterioration non-sticky coal and the hydroxypropyl methyl cellulose during mixing in the step (2), uniformly stirring, adding water, and continuously stirring to fully mix.

The molding pressure in the step (2) is 20-40MPa, and the pressing time is 5-20 min.

The invention has the beneficial effects that: 1. the low-deterioration non-sticky coal forming method can thoroughly solve the problems of long-distance transportation of low-deterioration pulverized coal. 2. The invention adopts only one organic binder besides water, is environment-friendly, and solves the problems of multiple types of binders, large addition amount and complex pretreatment process in the use process of the dust suppressant. 3. The invention has the characteristics of simple process, high forming speed and high forming rate, and the obtained coal briquette product without coal sticking has good quality and high mechanical strength (the compressive strength can reach 2.58 KN/piece to 4.18 KN/piece, and the falling strength can reach 87 percent to 99 percent).

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the present invention is not limited to the specific examples.

By adopting the pulverized coal molding method for solving the problem of long-distance transportation of the low-rank bituminous coal, the properties of the coal sample used in the experiment are shown in the table 1:

TABLE 1 Industrial and elemental analysis of Low-rank, non-caking coal

Note: is obtained by differential subtraction.

Example 1:

as shown in fig. 1, a pulverized coal molding method for solving the problem of long-distance transportation of low-rank bituminous coal comprises the following steps:

firstly, crushing, screening and drying low-metamorphic non-sticky coal;

step two, respectively weighing 85 wt% of the foxglove non-caking coal and 6 wt% of hydroxypropyl methyl cellulose according to the weight percentage, putting the foxglove non-caking coal and the 6 wt% of hydroxypropyl methyl cellulose into a beaker for mixing, adding 9 wt% of water after uniformly mixing, fully stirring and mixing, putting the mixture into a mould, then placing the mould under the pressure of 30MPa for cold press molding, and pressing for 5min to obtain cylindrical briquette

Each briquette weighed about 12 g.

Example 2:

firstly, crushing, screening and drying low-metamorphic non-sticky coal;

step two, respectively weighing 85 wt% of the foxglove non-caking coal and 6 wt% of hydroxypropyl methyl cellulose according to the weight percentage, putting the foxglove non-caking coal and the 6 wt% of hydroxypropyl methyl cellulose into a beaker for mixing, adding 9 wt% of water after uniformly mixing, fully stirring and mixing, putting the mixture into a mould, then placing the mould under the pressure of 40MPa for cold press molding, and pressing for 10min to obtain cylindrical briquette

Each briquette weighed about 12 g.

Example 3:

firstly, crushing, screening and drying low-metamorphic non-sticky coal;

step two, respectively weighing 88 wt% of the Fugu non-sticky coal and 3 wt% of the hydroxypropyl methyl cellulose according to the weight percentage, putting the mixture into a beaker for mixing, adding 9 wt% of water after uniformly mixing, fully stirring and mixing, putting the mixture into a mould, then placing the mould under the pressure of 30MPa for cold press molding, and pressing the mixture for 10min to obtain cylindrical briquette

Each briquette weighed about 12 g.

Example 4:

firstly, crushing, screening and drying low-metamorphic non-sticky coal;

step two, respectively weighing 88 wt% of the foxglove non-caking coal and 3 wt% of the hydroxypropyl methyl cellulose according to the weight percentage, putting the foxglove non-caking coal and the 3 wt% of the hydroxypropyl methyl cellulose into a beaker for mixing, adding 9 wt% of water after uniformly mixing, fully stirring and mixing, putting the mixture into a mould, then placing the mould under the pressure of 40MPa for cold press molding, and pressing for 5min to obtain cylindrical briquette

Each briquette weighed about 12 g.

Example 5:

firstly, crushing, screening and drying low-metamorphic non-sticky coal;

step two, respectively weighing 90 wt% of the Fugu non-sticky coal and 1 wt% of the hydroxypropyl methyl cellulose according to the weight percentage, putting the mixture into a beaker for mixing, adding 9 wt% of water after uniformly mixing, fully stirring and mixing, putting the mixture into a mould, then placing the mould under the pressure of 30MPa for cold press molding, and pressing the mixture for 20min to obtain cylindrical briquette

Each briquette weighed about 12 g.

The above examples were conducted to measure the falling strength and compressive strength of the modified briquettes in a unified manner, and the test results are shown in table 2:

TABLE 2 Properties of the briquettes

(1) Comparative example 1 is a low-rank, non-caking coal which was not treated using the process of the present invention;

(2) the falling strength test method of the lump coal comprises the following steps: freely falling 30mm lump coal onto a steel plate from a height of 2m, repeatedly falling for 3 times, sieving with a 5mm round hole sieve, and measuring the ratio of the weight of more than 5mm to the original weight.

(3) Compression strength of lump coal: placing the molded coal in a WDW-50 microcomputer control electronic universal tester, wherein the loading speed of the pressure tester is 10mm/min, and the compressive strength unit is as follows: newton (KN)

The test result shows that: compared with untreated low-deterioration non-caking coal, the briquette coal prepared by the method has good mechanical strength: the compressive strength can reach 2.58 KN/piece to 4.18 KN/piece, and the falling strength can reach 87 percent to 99 percent.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be accorded the broadest interpretation so as to encompass all equivalent modifications, variations, and equivalents as is consistent with the spirit of the invention.

Claims

1. A pulverized coal forming method for solving the problem of long-distance transportation of low-rank bituminous coal is characterized by comprising the following steps:

(1) crushing the low-deterioration non-sticky coal, screening and drying;

(2) 85-90 wt% of low-metamorphic non-sticky coal, 1-6 wt% of hydroxypropyl methyl cellulose and 9 wt% of water are uniformly mixed to form a mixture, and the mixture is pressed and molded in a molding die to obtain the molded coal.

2. The method for forming pulverized coal for solving the problem of long-distance transportation of low-rank bituminous coal according to claim 1, wherein the low-rank non-caking coal in the step (1) is dried in a forced air drying oven at 39 ℃ for 4 hours.

3. The method for forming pulverized coal for solving the problem of long-distance transportation of low-rank bituminous coal according to claim 1 or 2, wherein in the step (2), the low-rank non-caking coal and the hydroxypropyl methylcellulose are added during mixing, and after being uniformly stirred, water is added, and then stirring is continued to fully mix the low-rank non-caking coal and the hydroxypropyl methylcellulose.

4. The method for forming pulverized coal for long distance transportation of low rank bituminous coal according to claim 1, wherein the forming pressure in step (2) is 20-40MPa, and the pressing time is 5-20 min.