KR101449195B1 - Method for collecting hydrogen gas produced from leaching during hydrometallurgical process and apparatus for recycling of collected hydrogen gas - Google Patents
Method for collecting hydrogen gas produced from leaching during hydrometallurgical process and apparatus for recycling of collected hydrogen gas Download PDFInfo
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- KR101449195B1 KR101449195B1 KR1020120152517A KR20120152517A KR101449195B1 KR 101449195 B1 KR101449195 B1 KR 101449195B1 KR 1020120152517 A KR1020120152517 A KR 1020120152517A KR 20120152517 A KR20120152517 A KR 20120152517A KR 101449195 B1 KR101449195 B1 KR 101449195B1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
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Abstract
The present invention relates to a method for recovering hydrogen gas generated in a leaching step during a wet smelting process and an apparatus for recycling recovered hydrogen gas, wherein a plurality of leaching steps are performed in an overlapping manner to alleviate a change in the flow rate of recovered hydrogen gas So that it can be stably recycled to the hydrogen reduction process of the metal oxide.
Further, the present invention reduces the amount of hydrogen gas consumed in the reduction of the metal oxide, thereby reducing manufacturing costs.
Description
The present invention relates to a method for recovering hydrogen gas generated in a leaching step during a wet smelting process at a constant flow rate and an apparatus for recycling the recovered hydrogen gas to a hydrogen reduction process for metal oxides.
In the smelting and steelmaking processes, a hydrogen reduction process for reducing metal oxides using hydrogen has been widely used. Hydrogen reduction has a lower reduction temperature than carbon reduction and does not affect the composition of the raw material, which is advantageous in terms of economy.
During the hydrogen reduction process, the use of hydrogen reduction using a rotary kiln has been gradually expanded to a large extent. However, when hydrogen reduction is carried out using a rotary kiln, it is theoretically necessary to use hydrogen more than 1.5 to 2 times as much as the amount of hydrogen required for the reduction reaction, It is common to use only small-scale facilities.
In recent years, in order to solve such an economical problem, a technique of recovering and recycling surplus hydrogen that has not reacted in the reduction furnace has been proposed, and this technique effectively reduces the amount of hydrogen used.
Meanwhile, there are many cases where the hydrogen reduction and the wet smelting process are operated together according to the smelting process. When the hydrogen gas generated by the wet smelting process is recovered and utilized in the hydrogen reduction process, It is very economical enough to reduce the cost.
However, in a batch-type reactor, the amount of hydrogen gas generated during a certain period of time after the start of the introduction of the acid was greatly increased, and then decreased with the completion of the reaction. Thus, it was not easy to safely recover the hydrogen gas There is a problem.
However, it is possible to control by the method of compressing the hydrogen gas generated through the compressor. However, if the reaction tank itself is not maintained at a high pressure, the flow rate of the generated hydrogen gas is fluctuated, There is a risk that an outside air is introduced and the hydrogen gas is mixed with the inside to cause an explosion.
Therefore, in order to maintain the reaction tank at a high pressure, the reaction tank itself must be designed with a high-pressure facility, which is problematic from the economical point of view and has a limitation in increasing the capacity.
According to an aspect of the present invention, there is provided a method for recovering hydrogen gas generated in a leaching step during a wet smelting process, the method comprising: performing a leaching step in an overlapping manner to change a flow rate of recovered hydrogen gas So that the composition of high-pressure equipment is omitted when recycled to other processes.
Another aspect of the present invention relates to an apparatus for recycling a hydrogen gas, which recovers the hydrogen gas generated in the leaching step and recycles it to the hydrogen reduction process of the metal oxide.
According to an embodiment of the present invention, there is provided a method for producing hydrogen gas, comprising: a reducing step of reducing a raw material to a reducing gas containing hydrogen gas; A method for recovering hydrogen gas recovered in the leaching step of a metal smelting process including a leaching step of leaching a metal using an acid and a recovering step of recovering metal,
The leaching step is performed independently in each of a plurality of reaction vessels, and the leaching process is started in the second reaction vessel before the leaching process in the first reaction vessel is completed.
The leaching step may be independently performed in a plurality of reaction vessels connected in parallel.
The leaching process may be started in the second reaction tank at a time point when the amount of hydrogen generated by the leaching process performed in the first reaction tank is decreased.
The acid is one member selected from the group consisting of hydrochloric acid (HCl), sulfuric acid (H 2 SO 4) and nitric acid (HNO 3) Or more.
According to another embodiment of the present invention, there is provided a hydrogen recycling method for supplying the recovered hydrogen to a reducing gas in the reducing step.
The reducing gas may supply a gas containing hydrogen together with the recovered hydrogen.
According to another embodiment of the present invention, there is provided a process for producing hydrogen gas, comprising: a reduction step of reducing a raw material to a reducing gas containing hydrogen gas; An apparatus for recovering and recycling hydrogen gas generated in the leaching step of a metal smelting process including a leaching step of leaching a metal using an acid and a recovering step of recovering metal,
A plurality of reaction tanks including a raw material input portion and an acid leach solution outlet portion;
An acid inlet provided in the reaction tank and supplied with acid;
A gas outlet provided in the reaction tank and through which gas generated after the wet smelting process is discharged;
An acid vapor removing device connected to the gas exhaust port to remove acid vapor; And
And a hydrogen gas recovery device connected to the acid vapor removal device for recovering hydrogen gas,
The leaching step is performed independently in each of the plurality of reaction vessels, and the leaching process is started in the second reaction vessel before the leaching process in the first reaction vessel is completed,
Wherein the hydrogen gas recovery device is connected to a reduction furnace of a hydrogen reduction process of the metal oxide, and the recovered hydrogen gas is recycled to the hydrogen reduction process.
The plurality of reaction vessels may be connected in parallel.
The leaching process may be started in the second reaction tank at a time point when the amount of hydrogen generated by the leaching process performed in the first reaction tank is reduced.
The hydrogen gas recycling apparatus may further include an acid storage device storing the acid and connected to the acid solution input port.
The acid vapor removal device is connected to the gas outlet by a gas conduit,
The inner surface of the gas conduit may be coated with FRP (Fiber Reinforced Plastics).
The acid vapor removing device may further include a dust collecting device.
In one embodiment of the present invention, a plurality of leaching steps are carried out in an overlapping manner, so that the change in the flow rate of the recovered hydrogen gas is mitigated so as to be recycled to another process without performing high pressure compression, So that it can operate.
In another embodiment of the present invention, the hydrogen gas is recovered by reducing the flow rate change in a plurality of reaction vessels connected in parallel, thereby enabling the hydrogen gas to be stably recycled in the hydrogen reduction process of the metal oxide, Thereby reducing the production cost of hydrogen gas.
1 schematically illustrates a wet smelting process of a metal slurry in a basic batch reactor.
FIG. 2 is a schematic view illustrating a process of recovering hydrogen gas in two reaction vessels connected in parallel by way of an example of the recycling method of hydrogen gas of the present invention.
FIG. 3 is a graph showing changes in flow rate of hydrogen gas generated in the leaching step in Example 1. FIG.
FIG. 4 is a graph showing a change in flow rate of hydrogen gas generated in the leaching step in Comparative Example 1. FIG.
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.
According to an embodiment of the present invention, there is provided a method for producing hydrogen gas, comprising: a reducing step of reducing a raw material to a reducing gas containing hydrogen gas; A method for recovering hydrogen gas recovered in the leaching step during a wet smelting process of a metal including a leaching step of leaching metal using an acid and a recovering step of recovering metal, There is provided a method for recovering hydrogen gas, which is performed independently in a plurality of reaction tanks, wherein the leaching process is started in the second reaction tank before the leaching process in the first reaction tank is terminated, and the flow rate of recovered hydrogen gas is kept constant do.
In order to facilitate the supply of the metal in the reaction tank, the metal may be formed into a powder form, and then the metal slurry may be formed by mixing the powders and water in a weight ratio of 1: 1 to 1: 2.
FIG. 1 shows a leaching step during a wet smelting process of a metal slurry in a basic batch type reactor. When metal is supplied to a reaction tank and then hydrochloric acid is added, metal and hydrochloric acid react in the reaction tank, , And the metal is released in the form of an acid-dissolved solution, that is, an acid-leaching solution.
[Reaction Scheme 1]
M + HCl? MCl +? H2 (M is a monovalent metal, Li, K, etc.)
M '+ 2HCl → M'Cl₂ + H2 (M' is a divalent metal, Fe, Ni, Co, Mn, Cr,
The acid is one member selected from the group consisting of hydrochloric acid (HCl), sulfuric acid (H 2 SO 4) and nitric acid (HNO 3) Or more can be used.
On the other hand, the acid can be used as an acid solution, and it is preferable to use a solution in which an acid is diluted with water. When the acid of the present invention is used as the acid solution, the preferable concentration of the acid solution is 20% 35%. If the concentration exceeds 35%, the reaction temperature may increase to 90 ° C or higher, which may be undesirable.
In the recovering method of the present invention, the number of the facilities is not particularly limited in performing a plurality of leaching steps, but it is preferably performed independently in a plurality of reaction vessels connected in parallel in one facility.
In addition, the recovery method of the present invention preferably initiates the leaching process in the second reaction tank at a point of time when the amount of hydrogen generated by the leaching process performed in the first reaction tank is reduced. In this case, the hydrogen generation amount decrease time is generally a time after the hydrogen generation amount shows a maximum value as a change in the hydrogen generation amount with time in the leaching step, Can be considered as a point in time when a half of the time is consumed.
The present invention is characterized in that, by carrying out a plurality of leaching steps in a superposed manner as described above, it is possible to reduce the amount of hydrogen gas generated by the leaching process performed in the first reactor, The flow rate of the hydrogen gas is increased, and the change in the flow rate of the hydrogen gas that is ultimately recovered can be mitigated.
FIG. 2 shows an example of a method for recovering hydrogen gas according to the present invention, and schematically shows a process for recovering hydrogen gas in two reaction vessels connected in parallel. In FIG. 2, the size of the blue arrow indicates the relative flow rate of hydrogen gas generated in the leaching step. The flow rate of hydrogen gas generated in
According to another embodiment of the present invention, there is provided a hydrogen recycling method for supplying hydrogen gas recovered in the method for recovering hydrogen gas to a reducing gas in the reducing step. At this time, the reducing gas may supply a gas containing hydrogen together with the recovered hydrogen.
According to the method for recovering hydrogen gas of the present invention, it is possible to directly supply the recovered hydrogen to the reducing step without having to separately set high pressure equipment.
According to another embodiment of the present invention, there is provided a process for wet-refining a metal including a reducing step of reducing a raw material to a reducing gas containing hydrogen gas, a leaching step of leaching the metal using an acid, and a recovering step of recovering the metal A plurality of reaction tanks including a raw material input portion and an acid leach solution discharge portion, an acid input port provided in the reaction tank for supplying acid, An acid vapor removal device connected to the gas discharge port for removing acid vapor and a hydrogen gas recovery device connected to the acid vapor removal device for recovering hydrogen gas, Wherein the hydrogen gas recovery device is connected to a reduction furnace of the metal oxide hydrogen reduction process, The hydrogen gas provides an apparatus for recycling hydrogen gas that is recycled to the hydrogen reduction process.
In the recycling apparatus of the present invention, it is preferable that the leaching process is started in the second reaction tank before the leaching process of the first reaction tank among the plurality of reaction tanks is completed, wherein the plurality of reaction tanks may be connected in parallel.
Furthermore, it is more preferable to start the leaching process in the second reaction tank at a time point when the amount of hydrogen generated by the leaching process performed in the first reaction tank is reduced. In this case, the hydrogen generation amount decreasing time generally refers to a change in the amount of hydrogen generation over time in the leaching step as a graph in the form of a bell, that is, a time point after the maximum hydrogen generation amount has been reached, Can be considered as a point in time when a half of the time is consumed.
As described above, the leaching step is carried out in a plurality of reaction vessels in a superimposed manner, so that when the flow rate of the hydrogen gas generated in the first reaction vessel decreases, the flow rate of the hydrogen gas generated by starting the operation of the second reaction vessel So that it is possible to mitigate the change in the flow rate of the hydrogen gas that is ultimately recovered.
When the metal is introduced into the reaction tank through the raw material input portion, acid is injected into the reaction tank through the acid inlet, and hydrogen gas and acid leach solution are generated by the reaction between the metal and the acid. Since the generated hydrogen gas contains a part of the acid vapor, the acid vapor is removed through the acid vapor removing device connected to the gas outlet, and only the pure hydrogen gas can be recovered in the hydrogen gas recovering device. The acid leach solution may also be discharged to the acid leach solution outlet and used in subsequent processes.
The hydrogen gas recycling apparatus may further include an acid storage device for storing the acid and connected to the acid inlet.
The acid vapor removing device is connected to the gas outlet by a gas conduit, and the inner surface of the gas conduit may be coated with FRP (Fiber Reinforced Plastics). As described above, since the hydrogen gas discharged through the gas discharge port contains a part of the acid vapor, the corrosion resistance and acid resistance of the gas conduit can be improved through the FRP coating.
The acid vapor removing device may further include a dust collecting device. Since the hydrogen gas and the acid vapor generated by the wet smelting process may contain dust, it is preferable to remove the dust by a dust collector in order to recycle the hydrogen gas. At this time, the scrubber performs the dust collecting function, but it also has the function of removing the acid vapor, so it is preferable to use it as the acid vapor removing device and the dust collecting device.
According to the apparatus of the present invention, the acid gas and the dehydrated and completely recovered hydrogen gas are sent to the reducing furnace of the hydrogen reduction process and can be recycled to the metal oxide reduction process. At this time, the recovered hydrogen gas can be supplied to the reducing furnace at a constant flow rate, so that there is no need to provide a separate high pressure device, and the hydrogen reduction process can be continuously performed at a constant rate.
Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.
Example
[Example 1]
In order to facilitate the transfer, a reducing metal containing 60 to 70% by weight of iron was mixed with water at a weight ratio of 1.5: 1 to form a metal slurry.
Two reaction vessels having an internal volume of 8 m 3 were connected in parallel, and a slurry amounting to about 700 kg per reaction vessel was supplied. When iron slurry was added to the first reaction tank, a hydrochloric acid solution having a concentration of 20% was charged into the reactor at a weight of 4.2 times the weight of the slurry.
Since the total time required for the wet smelting process was one hour, the reaction between the iron slurry and the hydrochloric acid solution was continued for 30 minutes in the first reaction tank, and then the hydrochloric acid solution was added to the second reaction tank. The hydrogen gas produced in the two reaction vessels by the reaction between the iron slurry and the hydrochloric acid solution was passed through a water injection type scrubber and the flow rate was measured by a gas flow meter.
In order to make the same comparison in consideration of the difference in the amount of slurry, the flow rate value of the hydrogen gas measured through the gas flow meter was converted into the value per 1 ton of the slurry. As a result, the flow rate of the hydrogen gas The values are shown graphically in FIG.
[Comparative Example 1]
In order to facilitate the transfer, a reducing metal containing 60 to 70% by weight of iron was mixed with water at a weight ratio of 1.5: 1 to form a metal slurry.
The content of the reaction tank was set to 8 m 3 , and one reaction tank was prepared in a batch manner, and 700 kg of slurry was introduced. When the iron slurry was put into the reaction tank, a hydrochloric acid solution having a concentration of 20% was charged into the reactor at a weight of 4.2 times the weight of the slurry. The hydrogen gas generated by the reaction between the iron slurry and the hydrochloric acid solution was passed through a water injection type scrubber and the flow rate was measured by a gas flow meter.
In order to make the same comparison in consideration of the difference in the amount of slurry, the flow rate value of the hydrogen gas measured through the gas flow meter was converted into the value per 1 ton of the slurry. As a result, the flow rate of the hydrogen gas The values are shown graphically in FIG.
According to FIG. 3, the flow rate is an average value of approximately 170Nm 3 / h was calculated to be, higher relative to the average value are + 240Nm 3 / h, the average variation in the upper and lower low as -100Nm 3 / h of hydrogen gas to 70Nm 3 / h, and the flow rate of the hydrogen gas was maintained to be relatively uniform.
At this time, the recovered flow rate of the hydrogen gas satisfies the restriction condition of the dry type facility which restricts the input flow rate to 252 m 3 / h or less, and the hydrogen gas can be recycled to the dry type facility immediately after it is recovered.
On the other hand, according to FIG. 4, the flow rate of the hydrogen gas gradually increased to about 380 Nm 3 / h for 0.44 hr, and then the flow rate of the hydrogen gas gradually decreased for 0.56 hr.
As a result, it was confirmed that the effect of reducing the fluctuation of the flow rate of the hydrogen gas generated in the existing facilities by 60% or more was achieved only by constructing the reaction vessels in a parallel manner. Further, It is apparent that the flow rate of the hydrogen gas can be controlled more constantly.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.
Claims (12)
Wherein the leaching step is performed independently in each of a plurality of reaction vessels, wherein the leaching process is initiated in a second reaction vessel before the leaching process in the first reaction vessel is terminated.
A plurality of reaction tanks including a raw material input portion and an acid leach solution outlet portion;
An acid inlet provided in the reaction tank and supplied with acid;
A gas outlet provided in the reaction tank and through which gas generated after the wet smelting process is discharged;
An acid vapor removing device connected to the gas exhaust port to remove acid vapor; And
And a hydrogen gas recovery device connected to the acid vapor removal device for recovering hydrogen gas,
The leaching step is performed independently in each of the plurality of reaction vessels, and the leaching process is started in the second reaction vessel before the leaching process in the first reaction vessel is completed,
Wherein the hydrogen gas recovery device is connected to a reduction furnace of a metal oxide reduction process, and the recovered hydrogen gas is recycled to the hydrogen reduction process.
Wherein the inner surface of the gas conduit is coated with FRP (Fiber Reinforced Plastics).
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002029706A (en) * | 2000-07-10 | 2002-01-29 | Daikin Ind Ltd | Device and method for manufacturing hydrogen fluoride |
| KR20120011444A (en) * | 2010-07-29 | 2012-02-08 | 현대제철 주식회사 | Manufacturing method for hydrogen using slag and burner therewith |
| KR20120065874A (en) * | 2010-12-13 | 2012-06-21 | 재단법인 포항산업과학연구원 | Method for recovering nickel from nickel containing raw material |
| KR20130076554A (en) * | 2011-12-28 | 2013-07-08 | 주식회사 포스코 | Hydrogen recycling method and equipments in nickel recovery process |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002029706A (en) * | 2000-07-10 | 2002-01-29 | Daikin Ind Ltd | Device and method for manufacturing hydrogen fluoride |
| KR20120011444A (en) * | 2010-07-29 | 2012-02-08 | 현대제철 주식회사 | Manufacturing method for hydrogen using slag and burner therewith |
| KR20120065874A (en) * | 2010-12-13 | 2012-06-21 | 재단법인 포항산업과학연구원 | Method for recovering nickel from nickel containing raw material |
| KR20130076554A (en) * | 2011-12-28 | 2013-07-08 | 주식회사 포스코 | Hydrogen recycling method and equipments in nickel recovery process |
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