阅读说明：本技术 一种高灰难选煤泥中煤再浮工艺 (Coal refloating process in high-ash difficult-separation coal slime ) 是由 李延锋 陈朋 韩继康 张文志 卢皓植 荆隆隆 于 2021-06-17 设计创作，主要内容包括：本发明涉及一种高灰难选煤泥中煤再浮工艺,将煤泥水进入浮选机中进行分选,经浮选机分选后产生一二室精煤、三四室中煤(三四室溢流产品)、浮选尾煤三种产品,一二室精煤进入加压过滤机完成脱水作业,脱水后为浮选精煤产品；浮选机三四室中煤和加压过滤机滤液一起进入浮选柱进行分选,浮选柱溢流精煤进入快开压滤机进行脱水流程,脱水后产品和加压过滤机脱水后产品混合作为精煤产品；浮选机浮选尾煤和浮选柱底流尾煤进入尾煤浓缩机,尾煤浓缩机底流进入尾煤压滤机进行脱水作业,尾煤压滤机脱水产品作为尾煤出售；快开压滤机滤液和尾煤浓缩机溢流和尾煤压滤机滤液一起作为循环水回到系统中再利用；通过本发明实现了对难选煤泥全粒级的高效分选。(The invention relates to a high-ash difficult-separation coal slime middling refloating process, coal slime water is separated in a flotation machine, three products of first and second chamber clean coal, third and fourth chamber middling (three and four chamber overflow products) and flotation tail coal are generated after separation in the flotation machine, the first and second chamber clean coal enters a pressure filter to complete dehydration operation, and the products are flotation clean coal products after dehydration; the coal in the third chamber and the fourth chamber of the flotation machine and the filtrate of the pressure filter enter a flotation column together for separation, the overflow clean coal of the flotation column enters a quick-opening filter press for dehydration, and the dehydrated product of the pressure filter are mixed to be used as a clean coal product; flotation tail coal of the flotation machine and flotation column underflow tail coal enter a tail coal thickener, underflow of the tail coal thickener enters a tail coal filter press for dehydration operation, and a dehydrated product of the tail coal filter press is sold as tail coal; the filtrate of the quick-opening filter press, the overflow of the tailing coal thickener and the filtrate of the tailing coal filter press are used as circulating water to return to the system for reuse; the invention realizes the high-efficiency separation of the whole size fraction of the difficult-to-separate coal slime.)

1. A coal refloating process in high-ash difficult-separation coal slime is characterized in that: the method specifically comprises the following steps:

the first step, the slime water is separated by a main separation flotation mechanism to form first and second chamber clean coal, third and fourth chamber middlings and flotation tail coal, wherein the first and second chamber clean coal enters a main separation filter mechanism;

secondly, the first and second chambers of clean coal are separated into dehydrated first clean coal and filtrate I after passing through a main separation filtering mechanism, and the filtrate I and the third and fourth chambers of medium coal enter a re-separation flotation mechanism together;

thirdly, overflow clean coal and underflow tail coal are formed after being sorted by a re-sorting flotation mechanism, the overflow clean coal enters a re-sorting filtering mechanism, and the underflow tail coal and flotation tail coal enter a tail coal thickener;

fourthly, the second cleaned coal and the second filtrate are separated by a second separating and filtering mechanism to form dehydrated second cleaned coal and second filtrate, and the second cleaned coal and the first cleaned coal are mixed to form flotation cleaned coal;

fifthly, separating the tailings by a tailings thickener to form overflow and underflow, feeding the underflow into a tailings filtering mechanism, and separating to form filtrate III and dehydrated tailings;

and sixthly, converging the filtrate II and the filtrate III to form circulating water, and enabling the circulating water to enter a system for recycling, wherein the tail coal is the final filter-pressed coal slime.

2. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: the main flotation mechanism is a flotation machine.

3. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: the main filtering mechanism is a pressure filter.

4. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: the re-flotation mechanism is a flotation column.

5. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: the reselecting and filtering mechanism is a quick-opening filter press.

6. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: when the filtrate I and the coal in the three-four chambers enter the re-flotation mechanism together, the concentration is lower than 80 g/l.

7. The high-ash refractory coal slime medium-coal refloating process of claim 1, characterized in that: the main separation flotation mechanism separates three types of coal which are qualified clean coal in a first room and qualified clean coal in a second room, medium coal in a third room and tail coal in a fourth room respectively; and sorting qualified clean coal from the coal in the three chambers and the four chambers by a re-sorting flotation mechanism.

Technical Field

The invention relates to a coal refloating process in high-ash difficult-separation coal slime, belonging to the technical field of coal slime separation.

Background

Coal is used as main energy in China, plays an important role in the total production and consumption of primary energy, and is kept at a high level in order to guarantee the high-speed development of economy. Along with the continuous improvement of the mechanized coal mining degree, the primary coal slime proportion is also continuously improved, and the selectivity is poor; the market has continuously improved requirements on products and also puts higher requirements on the raw coal separation process.

The coal slime is separated mainly by adopting a flotation method, the previous coal slime is easy to separate, the product quality requirement is not high, and efficient separation can be achieved through one-time separation. With the continuous deterioration of the selectivity of the coal slime, the original separation process is difficult to separate qualified products; the situation that the clean coal of the flotation machine in the first and second chambers meets the requirement and the ash content of the overflow product in the third and fourth chambers is higher frequently occurs, the sale index of the clean coal is not met, the clean coal is called as middling coal, the ash back phenomenon of the clean coal in the first and second chambers is serious, and the yield of the clean coal cannot reach the highest. Meanwhile, in the original flotation process, a pressure filter is mostly adopted as dewatering equipment, solid particles in filtrate can not be directly used as circulating water and return to the flotation process again, and fine mud can be caused to circulate in a flotation system maliciously, so that the flotation system is collapsed, and the normal production of a coal preparation plant is influenced. Therefore, a new flotation process is urgently needed to solve the current problems.

Disclosure of Invention

The invention provides a coal refloating process in high-ash difficult-separation coal slime, which aims at the high-ash difficult-separation coal slime with the granularity of less than 0.5mm and realizes the efficient separation of the whole size fraction of the difficult-separation coal slime.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a coal refloating process in high-ash difficult-separation coal slime specifically comprises the following steps:

the first step, the slime water is separated by a main separation flotation mechanism to form first and second chamber clean coal, third and fourth chamber middlings and flotation tail coal, wherein the first and second chamber clean coal enters a main separation filter mechanism;

secondly, the first and second chambers of clean coal are separated into dehydrated first clean coal and filtrate I after passing through a main separation filtering mechanism, and the filtrate I and the third and fourth chambers of medium coal enter a re-separation flotation mechanism together;

thirdly, overflow clean coal and underflow tail coal are formed after being sorted by a re-sorting flotation mechanism, the overflow clean coal enters a re-sorting filtering mechanism, and the underflow tail coal and flotation tail coal enter a tail coal thickener;

fourthly, the second cleaned coal and the second filtrate are separated by a second separating and filtering mechanism to form dehydrated second cleaned coal and second filtrate, and the second cleaned coal and the first cleaned coal are mixed to form flotation cleaned coal;

fifthly, separating the tailings by a tailings thickener to form overflow and underflow, feeding the underflow into a tailings filtering mechanism, and separating to form filtrate III and dehydrated tailings;

step six, merging the filtrate II and the filtrate III to form circulating water, and enabling the circulating water to enter a system for recycling, wherein tail coal is final filter-pressed coal slime;

as a further preferred aspect of the present invention, the main flotation mechanism is a flotation machine;

as a further preferred aspect of the present invention, the main filtration mechanism is a pressure filter;

as a further preference of the present invention, the recleaning flotation mechanism is a flotation column;

as a further preferred aspect of the present invention, the reselecting filter mechanism is a quick-open filter press;

as a further preference of the invention, when the filtrate I and the coal in the three-four chambers enter the re-flotation mechanism together, the concentration is lower than 80 g/l;

as a further preferred option of the invention, the main flotation mechanism sorts three types of coal, namely, qualified clean coal in the first and second chambers, middlings in the third and fourth chambers, and tailings;

and sorting qualified clean coal from the coal in the three chambers and the four chambers by a re-sorting flotation mechanism.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, multiple separation mechanisms are skillfully matched with the original separation equipment to form a new separation process flow, so that the high-ash difficult-to-separate coal slime with the granularity of less than 0.5mm is efficiently separated;

2. the refloating process provided by the invention provides filtrate with qualified concentration (which can be used as circulating water to return to a system) through the quick-opening filter press, and realizes secondary enrichment by utilizing a thick foam layer of a flotation column and washing water to reduce fine mud entrainment and reduce clean coal ash content.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic view of a process flow provided by the present invention.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. In the description of the present application, it is to be understood that the terms "left side", "right side", "upper part", "lower part", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and that "first", "second", etc., do not represent an important degree of the component parts, and thus are not to be construed as limiting the present invention. The specific dimensions used in the present example are only for illustrating the technical solution and do not limit the scope of protection of the present invention.

With the continuous deterioration of the selectivity of coal slime, the problems that the ash content of coal in three or four chambers of a flotation machine is high and the vicious circulation of high-ash fine mud in filtrate of a pressure filter in a flotation system easily occurs in the current coal slime flotation process are solved, and aiming at the current situation, the application aims to provide a high-ash difficult-to-float coal slime medium coal refloating process, the coal in the three or four chambers of the flotation machine and the filtrate of the pressure filter enter a flotation column for separation, overflow clean coal is dehydrated through a quick-opening filter press to become a clean coal product, and the filtrate becomes circulating water; the combination of the flotation machine and the flotation column is utilized to realize the efficient separation of each grain size, the coarse separation and overflow entrainment are avoided, and the combined application of the pressure filter and the quick-opening filter press solves the problem that the high-ash fine mud is accumulated more and more in the flotation system on the premise of ensuring the treatment capacity.

Specifically, as shown in fig. 1, the process flow diagram of the coal refloating process in the high-ash refractory coal slime provided by the application specifically includes the following steps:

the first step, the slime water is separated by a flotation machine to form first and second chamber foam clean coal, third and fourth chamber middlings and flotation tail coal, wherein the first and second chamber foam clean coal enters a pressure filter;

secondly, separating the second clean coal into dehydrated first clean coal and filtrate I after passing through a flotation machine, enabling the filtrate I and the third and fourth chamber medium coals to enter a flotation column together, and enabling the concentration of the filtrate I and the third and fourth chamber medium coals to be lower than 80g/l when entering the flotation column together;

thirdly, overflow clean coal and underflow tail coal are formed after separation by a flotation column, the overflow clean coal enters a quick-opening filter press, and the underflow tail coal and flotation tail coal enter a tail coal thickener;

fourthly, separating by a quick-opening filter press to form a second dehydrated clean coal and a second filtrate, and mixing the second clean coal and the first clean coal to form a flotation clean coal;

fifthly, separating the tailings by a tailing thickener to form overflow and underflow, feeding the underflow into a tailing filter press, and separating to form filtrate III and dehydrated tailing;

and sixthly, converging the filtrate II and the filtrate III to form circulating water, and enabling the circulating water to enter a system for recycling, wherein the tail coal is the final filter-pressed coal slime.

That is to say, in the re-flotation process provided by the application, slime water enters a flotation machine for separation, three products of first-chamber clean coal, third-chamber medium coal and flotation tail coal are generated after separation by the flotation machine, the first-chamber clean coal enters a pressure filter to complete dehydration operation, and the first-chamber clean coal is sold as a flotation clean coal product (clean coal I) after dehydration. The coal in the three chambers and the filtrate filtered by the pressure filter after being separated by the flotation machine enter the flotation column one by one for separation, the overflow clean coal of the flotation column enters the quick-opening pressure filter for dehydration, the dehydrated product and the dehydrated product (clean coal II) of the pressure filter are mixed together and sold as a clean coal product, the high-ash fine mud in the filtrate I filtered by the pressure filter leaves the flotation system after passing through the flotation column and the quick-opening pressure filter, and the vicious circle of the high-ash fine mud in the system is avoided. The flotation tail coal separated by the flotation machine and the underflow tail coal separated by the flotation column enter a tail coal thickener together, the underflow of the tail coal thickener enters a tail coal filter press for dehydration, and the dehydrated product of the tail coal filter press is sold as tail coal; and the filtrate (filtrate II) of the quick-opening filter press, the overflow of the tailing coal thickener and the filtrate (filtrate III) of the tailing coal filter press are used as circulating water together and return to the system for reuse.

Through the process, the concentration of coal in the foam is high, the content of fine mud is high, and a flotation machine and a flotation column are used together, wherein the flotation machine is better for sorting large-particle coal slime, the concentration of filtrate is reduced through a pressure filter, the flotation column is better for sorting fine coal slime, secondary enrichment is realized by utilizing a thick foam layer of the flotation column and flushing water to reduce fine mud entrainment, the requirement of a three-chamber overflow product (middlings) with ash content easily exceeding the standard in the original process is met after sorting, and efficient sorting of the whole grain level of the coal slime, particularly the grain level of the coal slime to be less than 0.125mm is realized; meanwhile, the combined use of the pressure filter and the quick-opening filter press fully exerts the characteristics that the pressure filter has large treatment capacity and the filtrate of the clean coal quick-opening filter press can be used as circulating water.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "and/or" as used herein is intended to include both the individual components or both.

The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.