阅读说明：本技术 一种利用煤泥制备煤粉的方法 (Method for preparing coal powder by using coal slime ) 是由 于清航 崔豫泓 纪任山 罗伟 徐大宝 宋春燕 闫黎黎 曹好 姜思源 周沛然 张旭 于 2020-07-02 设计创作，主要内容包括：本发明公开了一种煤泥制备煤粉的方法。该方法包括如下步骤：1)将煤泥定量输进烘干打散窑,把原煤和石灰石通过振动给料器送入破碎机中；2)破碎后的原煤和石灰石及干煤泥通过电子皮带秤计量后均匀给入磨前仓再送入磨煤机内进行烘干粉磨；3)经过防爆布袋收尘器出来的成品煤粉进入储粉仓,之后仓内煤粉通过吨袋包装机或散装机进行装车发运。本发明所述煤泥为洗煤厂的含水煤泥,成本低廉,同时实现了对煤泥的高效处理,使其得到了最大化资源利用。(The invention discloses a method for preparing coal powder from coal slime. The method comprises the following steps: 1) quantitatively conveying the coal slime into a drying and scattering kiln, and conveying raw coal and limestone into a crusher through a vibration feeder; 2) the crushed raw coal, limestone and dry coal slime are metered by an electronic belt scale and then are uniformly fed into a pre-grinding bin and then are sent into a coal grinding machine for drying and grinding; 3) finished coal dust discharged by the explosion-proof cloth bag dust collector enters a powder storage bin, and then the coal dust in the bin is loaded and transported by a ton bag packing machine or a bulk machine. The coal slime is the hydrous coal slime of a coal washing plant, has low cost, and simultaneously realizes the high-efficiency treatment of the coal slime, so that the coal slime is maximally utilized.)

1. A method of producing coal fines comprising:

1) respectively feeding raw coal and limestone into a crusher through a vibrating feeder to be dried and crushed, respectively storing the raw coal and the limestone in a coal bunker and an auxiliary material bunker after metering, and respectively marking as raw coal a and limestone a;

drying and scattering the coal slime, and storing the coal slime in a coal slime powder bin, and marking as coal slime a;

spiral scales are arranged below the coal bunker, the auxiliary material bunker and the coal slime powder bunker for feeding and metering;

2) mixing and caching the raw coal a, the limestone a and the coal slime a in a pre-grinding bin, then sequentially entering a drying rotary kiln and a vertical mill for drying and grinding, then collecting by an explosion-proof cloth bag dust collector, and obtaining finished coal powder in a finished product bin;

the vertical mill is carried out in a coal mill;

the drying rotary kiln is carried out in a drying scattering kiln;

the heat sources of the drying rotary kiln and the vertical mill are provided by a hot air system;

the hot air system consists of a blower, a pulverized coal tower and a pulverized coal hot air furnace;

and air inlet pipelines of the drying rotary kiln, the vertical mill and the vertical mill are all connected with a nitrogen supplementing pipe for inert protection.

2. The method of claim 1, wherein: in the step 1), the feeding mass of the coal slime, the raw coal and the limestone is 10-45: 10-45: 1; specifically, 24: 25: 1;

the particle sizes of the raw coal a, the limestone a and the coal slime a are not more than 30 mm;

in the drying step, the moisture content of the dried material is not more than 5%.

3. The method according to claim 1 or 2, characterized in that: in the step 2), the coal powder hot-blast stove is a full-automatic low-nitrogen coal powder hot-blast stove.

4. A method according to any one of claims 1 to 3, wherein: the method further comprises the following steps: and (3) purifying the hot flue gas used for drying the vertical mill in the step 2) by using flue gas.

5. The method according to any one of claims 1 to 4, wherein: the inlet and outlet of the explosion-proof bag dust collector are provided with online monitoring equipment, inert gas protection and CO₂A fire suppression system;

the on-line monitoring equipment is selected from at least one of oxygen content monitoring, temperature monitoring, CO concentration monitoring and dust concentration monitoring.

6. The method according to any one of claims 1 to 5, wherein: the upper and lower positions of the finished product bin are provided with online monitoring equipment, inert gas protection and CO₂A fire suppression system;

the on-line monitoring equipment is selected from at least one of oxygen content monitoring, temperature monitoring, CO concentration monitoring and dust concentration monitoring.

7. The method according to any one of claims 1 to 6, wherein: all interfaces of all the equipment in the step 1) and the step 2) operate under the condition of full-closed full negative pressure.

8. The method according to any one of claims 1 to 7, wherein: the coal slime is water-containing coal slime of a coal washing plant.

Technical Field

The invention relates to a process method for preparing coal dust from coal slime, belonging to the technical field of solid waste recycling and coal dust preparation.

Background

Currently, the annual output of coal slime associated with raw coal washing in China is about 2 hundred million tons, and most coal washing plants stack the coal slime in the open air due to the high direct utilization difficulty, so that the huge waste of coal resources is caused, and the ecological environment is polluted. The coal slime has high water content, high viscosity, high water holding capacity, high ash content and low heat value, so that the effective treatment of the coal slime is difficult. The characteristic that the particle size of coal slime particles is small is utilized, the coal slime is coupled with the process of preparing coal powder by washing clean coal, and the coal powder prepared by the coal slime is used as the coal powder which can be used for boiler combustion, so that an effective way for utilizing the coal slime is provided.

The patent of publication No. CN106987297A discloses a coal slime fine powder preparation system and a process thereof, wherein the process adopts negative-pressure normal-temperature air flow to dry the water on the surface of coal slime particles, so that the purposes of low drying cost and low fuel consumption are achieved, but the problems of unsatisfactory drying effect and low wet coal slime treatment capacity exist.

The patent publication No. CN104492587A discloses that a coal slime filter cake is prepared from coal slime of an aerospace furnace and is burnt in a circulating fluidized bed boiler as fuel to realize recycling of the coal slime, but the method needs a large amount of water for spraying the coal ash in the preparation process of the coal slime filter cake, and brings a complicated water pollution problem.

The patent of publication No. CN106047426A discloses a method for preparing low-ash and low-sulfur coal water slurry by using coal slurry deep flotation to firstly obtain low-sulfur and low-ash flotation clean coal and then preparing the low-ash and low-sulfur coal water slurry by using the low-sulfur and low-ash flotation clean coal.

Disclosure of Invention

The invention aims to provide a preparation method for recycling solid wastes to prepare high-efficiency clean environment-friendly fuel for a high-efficiency pulverized coal industrial boiler, and organic unification of economic benefits, environment-friendly benefits and social benefits is realized.

The method for preparing the coal powder comprises the following steps:

1) respectively feeding raw coal and limestone into a crusher through a vibrating feeder to be dried and crushed, respectively storing the raw coal and the limestone in a coal bunker and an auxiliary material bunker after being measured by an electronic belt scale, and respectively marking the raw coal a and the limestone a;

drying and scattering the coal slime, and storing the coal slime in a coal slime powder bin, and marking as coal slime a;

spiral scales are arranged below the coal bunker, the auxiliary material bunker and the coal slime powder bunker for feeding and metering;

2) mixing and caching the raw coal a, the limestone a and the coal slime a in a pre-grinding bin, then sequentially entering a drying rotary kiln and a vertical mill for drying and grinding, then collecting by an explosion-proof cloth bag dust collector, and obtaining finished coal powder in a finished product bin;

the vertical mill is carried out in a coal mill;

the drying rotary kiln is carried out in a drying scattering kiln;

the heat sources of the drying rotary kiln and the vertical mill are provided by a hot air system;

the hot air system consists of a blower, a pulverized coal tower and a pulverized coal hot air furnace;

and air inlet pipelines of the drying rotary kiln, the vertical mill and the vertical mill are all connected with a nitrogen supplementing pipe for inert protection.

In the step 1) of the method, the feeding mass of the coal slime, the raw coal and the limestone is 10-45: 10-45: 1; specifically, 24: 25: 1;

the particle sizes of the raw coal a, the limestone a and the coal slime a are not more than 30 mm;

in the drying step, the moisture content of the dried material is not more than 5%.

In the step 2), the coal powder hot-blast stove is a full-automatic low-nitrogen coal powder hot-blast stove; the fuel is finished coal powder made by the system;

the method further comprises the following steps: and (3) purifying the hot flue gas used for drying the vertical mill in the step 2) by using flue gas.

The flue gas purification mode is various common flue gas purification modes; such as flue gas purification by a hot blast stove.

The explosion-proof clothOnline monitoring equipment, inert gas protection and CO are arranged at inlet and outlet of bag dust collector₂A fire suppression system;

the on-line monitoring equipment is selected from at least one of oxygen content monitoring, temperature monitoring, CO concentration monitoring and dust concentration monitoring.

The upper and lower positions of the finished product bin are provided with online monitoring equipment, inert gas protection and CO₂A fire suppression system;

the on-line monitoring equipment is selected from at least one of oxygen content monitoring, temperature monitoring, CO concentration monitoring and dust concentration monitoring.

All interfaces of all the equipment in the step 1) and the step 2) operate under the condition of full-closed full negative pressure.

The coal slime is specifically aqueous coal slime of a coal washing plant; the water content is 30-55%; more particularly 40-45%.

The invention solves the problems of coal slime accumulation, ineffective treatment and serious pollution; the coal slime can be changed into valuable after being processed and prepared by proportioning according to a certain proportion, and the SO generated during the combustion of the finished coal powder can be simultaneously generated by adding limestone₂Conversion of gas to CaSO₄Solid, effectively plays a role in sulfur fixation and reduces SO in fuel combustion flue gas₂Discharging to make the prepared finished coal powder become a high-efficiency clean environment-friendly fuel; the hot air system is provided with a full-automatic low-nitrogen pulverized coal burner, and the flue gas is purified, so that the environmental protection requirement can be met; the system is additionally provided with security means such as nitrogen protection, dust monitoring and the like, so that the safety of the whole system is further enhanced; it has the characteristics of energy conservation, environmental protection, high efficiency and safety.

Drawings

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

Detailed Description

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified.