RU2391508C1 - Complex development method of coal field - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: complex development method of coal field refers to mining, namely to complex development of coal field during underground coal gasification, and can be used for obtaining underground coal gasification products, heat carrier with specified parametres and for preproduction mining of rhenium. After generator gas leaves the well, first, it is cooled to the temperature not less than condensation temperature of gaseous rhenium compounds, and at that, heat energy is obtained for heat supply system; then gas is scrubbed in water, and at that, there obtained is rhenium-containing water solution, heating heat carrier and gas of increased humidity; at that, gas is dried, and rhenium-containing solution is cleaned from slurry and cooled; at that, there obtained is purified and dried gas, heat energy and rhenium-containing solution cleaned from mechanical impurities, which then is supplied for rhenium to be extracted e.g. with electrolysis.

EFFECT: increasing development efficiency owing to preproduction mining of rhenium, reducing harmful effect on environment.

1 dwg

Description

The present invention relates to mining, in particular to the integrated development of a coal deposit during underground coal gasification, and can be used to produce underground coal gasification products, a coolant with predetermined parameters and as a method for the associated production of rhenium.

A known method of integrated development of a coal field, including dividing the field into blocks, drilling degassing and drainage wells, preliminary degassing of coal seams and underground gasification of coal, with the issuance of surface degassing products of seams and coal gasification [1]. The disadvantage of this method is that many useful components, in particular rhenium and its compounds [2], in the process of underground coal gasification go into a gaseous state and are not captured and recovered in the future, thereby reducing the efficiency of developing a coal deposit.

The closest analogue adopted as a prototype is a method for integrated development of a coal field, including drilling a system of hydraulically coupled wells, performing hydrodynamic and fire effects through them on a coal seam, producing crude generator gas, cooling it to a temperature below the condensation temperature of the components included in the composition of the raw gas, and obtaining other useful components together with purified gas [3].

The disadvantage of the prototype is that during underground coal gasification, rhenium, which is part of the coal seams, goes into a gaseous state and leaves wells with underground coal gasification products in the form of rhenium and its oxides. Rhenium and its oxides are valuable chemical components that make up underground coal gasification products. The prototype does not allow rhenium to be distinguished from underground coal gasification products as a valuable component.

This drawback reduces the effectiveness of integrated development of a coal field.

The aim of the invention is to increase the efficiency of integrated development of a coal deposit due to the associated production of a valuable component - rhenium.

This goal is achieved by the fact that in the method of integrated development of a coal field, including drilling a system of hydraulically connected wells, performing hydrodynamic and fire effects through them on a coal seam, producing crude generator gas, cooling it to a temperature below the condensation temperature of the components that make up the raw gas , and obtaining together with the purified gas other useful components, upon exiting the well, the generator gas is cooled to a temperature not lower than the temperature of the cond sation gaseous rhenium compounds to yield thermal energy for the heating system; then the gas is washed in water and a rhenium-containing aqueous solution is obtained, a heating medium and a gas of high humidity; then the gas is dried, and the rhenium-containing solution is cleaned of sludge and cooled, and purified and dried gas, heat energy and a rhenium-containing solution purified from mechanical impurities are obtained, which are then sent to extract rhenium.

The method is illustrated by the primary processing scheme of underground coal gasification products.

The method of integrated development of a coal field can be implemented as follows. Well 1 by a pipe 2 is connected to a heat exchanger 3 included in the heat supply system through pipelines 4 (T2) and 5 (T1). Further along the products of underground gasification, a horizontal cylindrical tank 6 is installed, approximately half filled with water. A blank shield 7 is installed vertically in the interior of the vessel 6, preventing the free entry of underground gasification products into the gas space and directing them into the water space of the vessel 6. An approximately horizontally perforated shield 8 is welded to the lower edge of the blind shield 7 and to the ends of the horizontal vessel 6, having a large the number of small diameter holes uniformly distributed over the shield area. The gas space of the tank 6 is connected through the pipeline 9 to the gas space of the cyclone 10, and the water space through the pipe 11 to the water space of the cyclone 10. Through the pipe 12, the water space of the cyclone 10 is connected to the precipitator 13, equipped with a removable bottom 14. Next, a heat exchanger is installed along the liquid 15, included by pipelines 16 (T4) and 17 (T3) in a system, for example, hot water supply. The output of the heating fluid 18 from the heat exchanger 15 is made into an electrolysis bath 19 provided with electrodes 20. By pipelines 21, 23 and a pump 22, the electrolysis bath 19 is connected to the water space of the tank 6 by means of a pipe 24 made, for example, at its end.

The processing scheme of gaseous products of underground coal gasification works as follows. Hot products of underground gasification from the well 1 through the pipeline 2 enter the heat exchanger 3, where they give part of the heat to the water of the heating system T1-T2. The products of underground coal gasification cooled to a temperature not lower than the condensation temperature of rhenium oxides are piped into the tank 6 into the space between its wall and the dull shield 7. The dull shield 7 directs the gas flow into the water space of the tank 6 under the immersion hole shield 8 for washing. Due to the presence of a large number of holes of small diameter, shield 8 distributes the gas volume over its entire area and passes it to the surface of the water in small bubbles, thereby increasing the area of gas contact with water. Passing to the surface through a layer of water above the hole shield 8, the gas is cooled to a temperature well below the condensation temperature of rhenium oxides. At the same time, the gas cooling temperature can be controlled both by changing the temperature of the water in the tank, and by changing the thickness of its layer above the shield 8. When washing the gas in the water, mechanical impurities remain and rhenium oxides dissolve, forming a rhenium-containing solution. Passing to the surface of the water, the gas forms a fluidized bed, which releases a certain amount of water vapor into the gas space of the tank 6, which helps dissolve rhenium oxides which are not dissolved in water. The wet gas through the pipe 9 enters the cyclone 10, where the gas is drained. Next, the dried gas is sent to the consumer.

The rhenium-containing solution from the tank 6 through the pipe 11 enters the cyclone 10, where it is mixed with a similar solution obtained by the separation of wet gas. Next, the rhenium-containing solution through the pipe 12 enters the precipitator 13, where due to the difference in the cross section of the flow of mechanical impurities are precipitated, settling at the bottom of the precipitator. The purified rhenium-containing solution enters the heat exchanger 15, pipes 16 and 17 included in the system, for example, hot water T3-T4, where it is cooled to a temperature below the boiling point at atmospheric pressure. After the heat exchanger 15, the cooled rhenium-containing solution is directed to the extraction of rhenium by one of the known methods, for example by electrolysis. For this, a rhenium-containing solution is sent through a pipe 18 to an electrolysis bath 19 with electrodes 20. From the same bath, pipelines 21 and 23 process water by a pump 22 into the water space of a tank 6.

When the rhenium-containing solution is repeatedly passed through the circulation circuit "electrolysis bath - capacity - cyclone - precipitator", the concentration of rhenium compounds in it continuously increases and at some point in time becomes sufficient to isolate rhenium by electrolysis. For this, an electric current is supplied to the electrodes 19 of the electrolysis bath 18, due to which rhenium is deposited on one of the electrodes.

The achieved effect is that the method allows to obtain not only valuable fuel and thermal energy of a given potential, but also a valuable substance, which is rhenium. That is, the claimed method improves the efficiency of integrated development of a coal field, and this is the purpose of the invention.

Information sources

1. A method of producing electricity during shaftless coal gasification and / or underground coal burning / RF Patent No. 2100588, publ. 1997.12.27 (analogue).

2. Yudovich Ya.E., Ketris M.P. Valuable impurities in coals. Yekaterinburg: Ural Branch of the Russian Academy of Sciences, 2006, p.376.

3. Kreinin EV Is an environmentally friendly coal-energy complex possible / Coal, 1 - 2008, p. 38-40 (prototype).

Claims (1)

A method for the integrated development of a coal field, including drilling a system of hydraulically coupled wells, performing hydrodynamic and fire effects through them on a coal seam, producing crude generator gas, cooling it to a temperature below the condensation temperature of the components that make up the raw gas, and producing it together with purified gas other useful components, characterized in that upon leaving the well, the generator gas is cooled to a temperature not lower than the condensation temperature of the gaseous of rhenium compounds, this produces heat energy for the heat supply system, then the gas is washed in water and a rhenium-containing aqueous solution, a heating medium and high humidity gas are obtained, then the gas is dried, and the rhenium-containing solution is cleaned of sludge and cooled, and purified and dried gas, thermal energy and a rhenium-containing solution purified from mechanical impurities, which is then sent to extract rhenium.

Images