RU2304467C2 - Coal concentration method - Google Patents

Abstract

FIELD: processes for separating carbon-containing component of natural coal, coal slime or waste materials of coal concentration, possibly in coal, fuel and metallurgical industry branches for producing high-grade, high-calorie, low ash content coal.

SUBSTANCE: method for concentrating coal comprises steps of mixing initial coal raw material and water for receiving water-coal suspension; adding to said suspension agglomerating agent; separating carbon-containing component of coal raw material and ash in water-coal suspension; extracting carbon-containing component by flotation; in addition introducing frothing agent to water-coal suspension and separating carbon-containing component of coal raw material and ash by means of steam blown-in by separate streams for thinning ash-fraction component. Water-coal suspension includes 7.00 - 50.00 mass parts of water per 1 mass part of coal. Flow rate of steam is no more than 500 kg per ton of initial coal raw material. Flow rate values of agglomerating agent and frothing agent are in range 3 - 7 kg and 0.05 -0.15 kg respectively per 1 t of water-coal suspension.

EFFECT: reduced expenses for realization of method, less loss of yield of carbon-containing component, enhanced efficiency of removing ash from carbon-containing component.

9 cl, 2 tbl, 6 ex

Description

The invention relates to technologies for the separation of the carbon-containing component of natural coal, coal sludge or coal-processing waste and can be used in the coal, fuel and metallurgical industries to produce high-grade, high-calorie, low-ash coal.

A large number of coal enrichment technologies are known, which consist in separating the carbon-containing component from the mineral-containing component, also called ash, including waste rock and clay, and the subsequent separation of the named carbon-containing component, among which flotation-based technologies occupy a special place.

For example, a method for desalting coal is known, including preparing a suspension from coal and water, adding an agent capable of reacting with undesirable clay minerals to form a water-soluble complex, where the base solution has a pH of 7-13 and a concentration of a water-soluble complex of 50-5000 liquid parts per 1 million parts of water, the separation of coal and sludge by foam flotation, the formation of filtered pieces from the separated coal, the drying of these pieces, dry foam treatment and complete filtering are filtered th coal [U.S. Patent №5402894]. This method is characterized by high costs and complexity of the technology.

There is also known a method of desoldering coal by flotation, in which the source of natural coal is ground to a particle size of about 150 microns, then mixed with an emulsion of a hydrocarbon liquid containing an agglomerating agent, which is a mixture of light and heavy oil fractions, and water, so that the particles Coal was wetted primarily with a hydrocarbon liquid, and hydrophilic gangue particles were dispersed in water, forming a suspension. In the presence of raw coal, carbon-containing particles agglomerate. Next, the suspension of gangue is removed together with water, and the agglomerated particles of the carbon-containing component are treated with dry steam that does not contain oxidizing ingredients and has a temperature of 100-245 ° C to separate the agglomerating agent from coal particles [US Patent No. 4396396]. This method is the closest analogue to the greatest number of similarities with the proposed method for coal beneficiation, and is taken as a prototype of the invention.

The disadvantages of the prototype are the high costs of its implementation, high ash content obtained as a result of the implementation of the method of the carbon-containing component and its low yield.

The invention solves the problem of creating a method for the enrichment of coal, which would be characterized by low costs for its implementation, a high degree of ash removal from the carbon-containing component obtained as a result of the method, as well as its high yield.

To solve this problem, a coal enrichment method is proposed, in which the initial coal raw material and water are mixed to obtain a water-coal suspension, to which then an agglomerating agent and a foaming agent are added, after which the water-coal suspension is treated with water vapor, which is fed into it in separate jets thereby separating the carbon-containing component and the ash, after which the named carbon-containing component is isolated by flotation, while the water-coal suspension contains 7.0-50.0 wt. parts of water per 1 wt. part of the coal, and the consumption of water vapor is not more than 500 kg per ton of raw coal, the consumption of sintering agent is 3-7 kg, and the foaming agent is 0.05-0.15 kg per ton of water-coal suspension.

The initial coal raw material may be natural coal with a particle size of not more than 3 mm.

The initial coal feed may also be coal sludge with a particle size of not more than 0.6 mm or coal treatment waste with a particle size of not more than 3 mm.

Coking or sintering coal with a particle size of not more than 3.0 mm may also be a raw coal feed.

If the feed coal has a larger particle size, it is advisable to grind to the above sizes.

The optimal ratio of water and coal in a water-coal suspension depends on its type, particle size and ash content. So, if the initial coal feed is coking or sintering coal with a particle size of not more than 3 mm, it is advisable that the water-coal suspension contains 8.0-13.0 wt. parts of water per 1 wt. part of the coal. If the original coal feed has an ash content of less than 80%, but more than 50%, it is advisable that the water-coal suspension contains 10.0-50.0 wt. parts of water per 1 wt. part of the coal. And if the source of coal raw materials has an ash content of less than 50%, the water-coal suspension should contain 7.0-10.0 wt. parts of water per 1 wt. part of the coal.

As the agglomerating agent, conventional hydrocarbon liquids or thermogas oils can be used, which are a mixture of light and heavy oil fractions selected so that the coal particles are wetted by the agent first and the hydrophilic ash particles are dispersed in water.

Conventional blowing agents can also be used as a blowing agent to aid the adherence of air bubbles to carbon-containing particles.

The proposed method of coal preparation is as follows. Natural coal with an ash content, for example, 48% is crushed by known methods to an optimum size of 3 mm for its enrichment, or a fraction of the initial coal of the indicated size is separated also by known methods. Next, the coal particles are mixed with water in a ratio of 7-10 wt. parts of water per 1 wt. part of the coal. Agglomerating agent, for example, thermogasoil, light catalytic cracking and coking, in the amount of 5.8 kg and a blowing agent, for example, CATHOL, in the amount of 0.1 kg are added to the resulting mixture. The result is a water-coal suspension in which initially part of the ash forms a suspension in water, and part of the ash is held on the surface of the coal particles.

Said water-coal suspension is placed in a screw, pipe, or inclined tray, or other means by which the water-coal suspension can be moved. When advancing the mixture, it is treated with jets of water vapor at a steam speed not exceeding the speed of sound.

Water vapor condenses on the surface of the coal particles, as a result of which ultrasonic pressure oscillations occur, propagating into the volume of the water-coal mixture. This leads to a softening of the soaking constituent of the ash fraction, the appearance of oscillating vapor-gas bubbles in the microcavities of the aggregations of ash and coal particles, which contribute to the destruction of these aggregates.

In addition, the condensation of steam in a coal-water suspension allows dispersing and weighing ash particles in water, preventing them from sticking together. An additional dispersing effect occurs due to the known effects of degassing, dissolved in a water-coal suspension of air and separation of surface-active substances from ash and coal particles, followed by their emulsification due to the occurrence of ultrasonic vibrations during condensation of a steam jet in a mixture.

The agglomerating and foaming agents added to the water-coal suspension are dispersed and evenly distributed over the volume of the suspension under the influence of condensing steam jets. The result is a more efficient interaction of the agents with carbon particles and a more efficient separation of the carbon component and ash. The water-carbon suspension thus prepared, in which the separation of the carbon-containing component and water occurred, goes to flotation, where the target product, the carbon-containing component, is isolated.

Example 1

Natural coal with an ash content of 48% and particle sizes of 8-20 mm is crushed by known methods to a size of 3 mm. Next, the crushed coal is mixed with water in a ratio of 8 wt. parts of water per 1 wt. part of the coal. An agglomerating agent, thermogasoil of light catalytic cracking and coking produced by the Omsk Oil Refinery, in the amount of 2.9 kg and a foaming agent, KETGOL manufactured by Perm Siburkhimprom, in the amount of 0.05 kg per ton are added to the resulting mixture. Next, the water-carbon suspension is treated with water vapor jets at a speed a pair not exceeding the speed of sound. Steam consumption is 300 kg per ton of coal. After this, the suspension is subjected to flotation. The result is a carbon-containing component in an amount of 49.5%, and the ash content in the resulting carbon-containing component is 5.5%, and 83.2% in the waste.

Example 2

The same as in example 1, but the method is carried out according to the prototype. The result is a carbon-containing component in an amount of 45.6%, and the ash content in the resulting carbon-containing component is 12.8%, and 77.5% in waste.

Example 3

Natural coal with an ash content of 68% and a particle size of 3 mm is mixed with water in a ratio of 35 wt. parts of water per 1 wt. part of the coal. An agglomerating agent, thermogasoil of light catalytic cracking and coking produced by the Omsk Oil Refinery, in the amount of 3.9 kg and a foaming agent, KETGOL manufactured by Perm Siburkhimprom, in the amount of 0.1 kg per 1 ton are added to the resulting mixture. Next, the water-carbon suspension is treated with jets of water vapor with a steam speed not exceeding the speed of sound. Steam consumption is 400 kg per 1 ton of coal. After that, it is subjected to flotation. The result is a carbon-containing component in an amount of 43.6, and the ash content in the carbon-containing component is 9.3%, and 88.2% in the waste.

Example 4

The same as in example 3, but the method is carried out according to the prototype. The result is a carbon-containing component in an amount of 42.6%, and the ash content in the resulting carbon-containing component is 10.4%, and in the waste - 90.2%.

Example 5

Coal sludge with an ash content of 72% and a particle size of 0.6 mm is mixed with water in a ratio of 35 wt. parts of water per 1 wt. part of the coal. An agglomerating agent, thermogasoil of light catalytic cracking and coking produced by the Omsk Oil Refinery, in the amount of 5.8 kg and a foaming agent, KETGOL manufactured by Perm Siburkhimprom, in the amount of 0.1 kg per 1 ton are added to the resulting mixture. Next, the water-carbon suspension is treated with jets of water vapor with a steam speed not exceeding the speed of sound. Steam consumption is 500 kg per 1 ton of coal. After that, it is subjected to flotation. The result is a carbon-containing component in an amount of 18.8%, and the ash content in the resulting carbon-containing component is 10.3%, and in the waste - 93.4%.

Example 6

The same as in example 1, but the method is carried out according to the prototype. The result is a carbon-containing component in an amount of 25.8%, and the ash content in the obtained carbon-containing component is 14.0%, and in the waste 91.0%.

Table 1 shows information regarding the implementation of the proposed method according to the examples, and in table 2 the prototype under the same initial conditions.

Comparison of the data obtained showed that the described method allows to increase the yield of the carbon-containing component while decreasing its ash content.

Thus, the proposed method is simple, as well as a higher yield of carbon-containing concentrate with a lower ash content.

Table 1 Example No. The concentration of agents, g / t results Carbon component Waste Agglomerating Foaming Exit, % Ash,% Exit, % Ash,% one 2900 fifty 49.5 5.5 50,5 83,2 3 3900 one hundred 43.6 9.3 56.4 88.2 5 5800 one hundred 25.8 10.3 74,2 93,4

table 2 Example No. The concentration of agents, g / t results Carbon component Waste Agglomerating Foaming Exit, % Ash,% Exit, % Ash,% 2 2900 fifty 45.6 12.8 54,4 77.5 four 3900 one hundred 42.6 10,4 57.4 90.2 6 5800 one hundred 24.6 14.0 75,4 91.0

Claims (9)

1. A method of coal enrichment, in which the raw coal feed and water are mixed to obtain a water-coal suspension, into which an agglomerating agent is also introduced, then the carbon-containing component of the coal raw material and ash are separated in the said water-coal suspension and the named carbon-containing component is isolated by flotation, characterized in that a blowing agent is additionally added to said water-coal suspension, and the carbon-containing component of the coal feed and the ash are separated by treating the said water-coal suspension stretch water vapor, which is fed into it in separate jets, while the water-coal suspension contains 7.0-50.0 parts by weight water per 1 wt.h. coal, and the consumption of water vapor is not more than 500 kg per ton of coal feedstock, the consumption of sintering agent is 3-7 kg, and the foaming agent is 0.05-0.15 kg per ton of coal-water suspension. 2. The method according to claim 1, characterized in that the source of coal is natural coal with a particle size of not more than 3 mm 3. The method according to claim 1, characterized in that the source of coal is coal slurry with a particle size of not more than 0.6 mm 4. The method according to claim 1, characterized in that the source of coal is coal enrichment waste with a particle size of not more than 3 mm 5. The method of coal enrichment according to claim 1, characterized in that the initial coal feed is coking or sintering coal with a particle size of not more than 3.0 mm 6. The method of enrichment of coal according to claim 1, characterized in that the feed coal is pre-crushed. 7. The method of enrichment of coal according to claim 1, characterized in that the feed coal has an ash content of less than 80%. 8. The method of enrichment of coal according to claim 1, characterized in that the feedstock has an ash content of less than 50%. 9. The method of coal enrichment according to claim 1, characterized in that the agglomerating agent is thermogasoil light catalytic cracking and coking.