KR102262189B1 - Apparatuses of recycling of aluminum dross - Google Patents

Abstract

The present invention is equipped with a first reactor having a scraper and an air flow control valve, an inlet that can spray water in two directions from the top, and a second reactor and an ignition device of a bent type having a solution circulation function for concentration of the solution It relates to an aluminum dross treatment device composed of a combustor, and because it uses the oxidation heat of aluminum contained in the aluminum dross, no external energy input is required, and the removed chlorine component can be recovered and utilized as an iron chloride solution. An aluminum dross processing apparatus can be provided.

Description

Apparatus of recycling of aluminum dross

The present invention relates to a treatment apparatus for aluminum dross, and more particularly, to a treatment apparatus and method for producing a solid mixture containing alumina as a main component, sodium salt and iron chloride, etc. from aluminum dross generated during aluminum smelting and casting. it's about

Background to the present disclosure is provided herein, which does not necessarily imply known art.

The dross generated in the aluminum melting process to obtain high-purity alumina is the removal of the oxide layer formed on the surface of the molten metal when the aluminum is melted. Scraps containing aluminum are further classified into white dross, black dross, and salt cake in terms of recycling. White dross is remelted to recover aluminum, and the remaining black dross generally contains about 12-18% recoverable metallic aluminum.

Nevertheless, recycling of black dross is not easy. This is because most of the dross is composed of fine metal particles and oxides, metal fragments of aluminum alloy components, and a heterogeneous mixture of large lumps.

The main component of aluminum dross is about 5-60% aluminum, in addition to alumina, aluminum nitride, aluminum chloride, aluminum alloy components, MgF ₂ , NaAlCl ₄ , KAlCl ₄ , silica, MgO, spinel and salt components. exist. Aluminum hydroxide is also present, which is a result of the reaction of metallic aluminum with water, which became alkaline due to AlN in dross.

As described above, most of the aluminum dross cannot be recycled due to various impurities and is treated as waste. Dross treated as waste contains a lot of alumina, aluminum, silica, etc., so it can be recycled as a raw material for cement, but it is a constraint due to chlorine in impurities.

To remove chlorine components, a method of washing with water is used, but the water generated after washing contains various impurities, so the cost of wastewater treatment occurs. Also, in order to remove chlorine components below a certain concentration, the scale of washing facilities becomes large. This incurs equipment and operating costs. In addition, since aluminum reacts with moisture to generate hydrogen, there is also a risk of explosion.

1. Korean Patent Registration No. 10-1906802 (2018.10.04.)

In order to solve the above problems, the present invention is to provide a treatment apparatus and treatment method capable of producing a solid mixture containing alumina as a main component while minimizing the amount of water used, no wastewater generation, and recovering sodium and chlorine as useful components will be.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention is a first reactor capable of generating hydrogen chloride gas by inputting aluminum dross, a carbon component, and water; a second reactor for preparing an iron chloride solution by introducing hydrogen chloride gas, an iron component, and water generated from the first reactor; and a combustor including an ignition device for combusting the exhaust gas generated from the second reactor.

In addition, the first reactor is provided with an aluminum dross inlet and a carbon component inlet, a flow control valve and a nozzle through which air for temperature control of the first reactor is introduced, and the first reactor is provided with a water inlet line at the lower portion Discharging the sodium salt solution by washing the sodium salt produced in the first reactor, and discharging the solid mixture produced in the first reactor by providing a scraper.

In addition, the second reactor is provided with a hydrogen chloride inlet line, an iron component inlet line and a water inlet line transferred from the first reactor, and a line for circulating the solution discharged from the lower part of the second reactor back to the upper part of the second reactor characterized in that

In addition, the second reactor has a partially divided upper part, and the water inlet line is provided in a form that can be sprayed in two directions from the upper part of the second reactor so that the hydrogen chloride inlet line side and the circulation line side are respectively sprayed. characterized.

In addition, the combustor burns hydrogen in the flue gas transferred from the second reactor to convert it to water and discharge it.

Since the present invention mainly uses the heat of oxidation of aluminum contained in aluminum dross and auxiliary heat of oxidation of carbon, there is no need to input external energy to maintain the reaction except for external energy to initially start the reaction. , We provide an eco-friendly, non-polluting aluminum dross treatment device and treatment method that not only recovers sodium salt solution and iron chloride solution to recycle it, but also recycles alumina-based solid mixture, detoxifies exhaust gas and generates no waste at all can do.

1 shows the configuration of an aluminum dross processing apparatus according to an embodiment of the present invention.
Figure 2 shows the steps of the aluminum dross processing method according to an embodiment of the present invention.

All technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art, unless otherwise stated. Also throughout this specification and claims, unless stated otherwise, the term comprise, comprises, comprising is meant to include the recited object, step or group of objects, and steps, and any other It is not used in the sense of excluding an object, step, or group of objects or groups of steps.

Prior to describing the present invention in detail below, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which is limited only by the appended claims. shall.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. Any feature indicated as particularly preferred or advantageous may be combined with any other feature and features indicated as preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

The aluminum dross processing apparatus according to the present invention includes a first reactor 10 capable of generating hydrogen chloride gas by inputting aluminum dross, a carbon component, and water, a hydrogen chloride gas generated from the first reactor, an iron component, and water by inputting iron chloride It is configured to include a second reactor 20 for preparing a solution and a combustor 30 including an ignition device for burning the exhaust gas generated from the second reactor.

The first reactor 10 is provided with an aluminum dross inlet and a carbon component inlet, and a flow control valve and nozzle through which air for temperature control of the first reactor is introduced. By measuring the temperature inside the first reactor, the flow rate of the inflow of air is controlled to obtain an appropriate reaction temperature. Air may be introduced at a rate of 20 to 60 m ^{3 /hr.}

Aluminum dross and carbon components are introduced into the first reactor 10, and air is forced through a nozzle connected to the first reactor to cause a reaction. Except for external energy (forced input of air) to start the reaction in the initial stage, since the oxidation heat of aluminum is mainly used and the oxidation heat of carbon is used auxiliary, there is no need for additional external energy input to maintain the reaction. have.

Aluminum dross is mainly aluminum (Al), and in addition to aluminum oxide, aluminum nitride, aluminum chloride, aluminum alloy component metals and NaCl, MgCl, KCl, MgF ₂ , NaAlCl ₄ , KAlCl ₄ , silica, MgO, spinel and Salt components are present.

Aluminum (Al) reacts with oxygen in the air introduced into the first reactor to generate oxidation heat while generating an oxide. The produced aluminum oxide is sent to the lower part of the reactor and discharged to a separate solid mixture line through a scraper provided at the lower part of the reactor. The solid mixture line also includes oxides of Mg, Si and Ca components contained in other aluminum dross.

The carbon (C) component may be added, for example, in the form of coke. In the first reactor to generate the injected carbon (C) component is burned and the CO ₂ generation, the generated CO ₂ and H ₂ O is salt component, e.g., NaCl reacts with the hydrogen chloride (HCl) and sodium salts.

2NaCl + CO ₂ + H ₂ O -> Na ₂ CO ₃ + 2HCl

NaCl + H ₂ O -> NaOH + HCl

The produced sodium salt, for example, Na ₂ CO ₃ , NaOH, etc. is washed with water flowing into the lower part of the reactor and then discharged to a separate sodium salt solution line. The produced hydrogen chloride (HCl) gas is transferred to the second reactor.

A portion of the water flowing into the lower portion of the first reactor may be evaporated by the temperature inside the reactor to help the reaction.

The second reactor 20 is provided with a hydrogen chloride inlet line, an iron component inlet line, and a water inlet line transferred from the first reactor, and reacts the introduced hydrogen chloride, iron component and water to produce an iron chloride solution. In the second reactor, the upper part is partially divided to maximize the contact of hydrogen chloride with iron components and water.

The iron (Fe) component _{may be added in the form of Fe metal or Fe 2} O ₃ (in the form of scrap). Preferably, it is good to input in the form _{of Fe 2} O _{3 hydrogen (H 2} ) to reduce the amount of generation. The hydrogen chloride generated in the first reactor reacts with the iron component to produce iron chloride (III, II). At this time, the hydrogen (H ₂ ) generated together is a combustible gas because there is a risk of explosion if it is included in the flue gas in a large amount.

6HCl + Fe ₂ O ₃ -> 2FeCl ₃ + 3H ₂ O

2HCl + Fe -> FeCl ₂ + H ₂

In addition, a line for circulating the solution discharged from the lower portion of the second reactor 20 back to the upper portion of the second reactor is further provided to concentrate the concentration of the iron chloride solution.

The water inlet line is provided in a form that can be sprayed into two branches from the upper part of the second reactor so that the hydrogen chloride inlet line side and the circulating line side are respectively sprayed.

_{The exhaust gas including hydrogen (H 2} ) generated in the second reactor is transferred to the combustor 30 .

The combustor 30 includes an ignition device for burning _{hydrogen (H 2} ) in the exhaust gas. Through the combustor 30 , hydrogen (H ₂ ) gas is converted to water, detoxified and discharged, thereby eliminating the risk of explosion.

The aforementioned inlet and outlet lines are introduced and discharged including the aforementioned components, and other components that may be included and other components generated in the reaction are introduced and discharged. When processing 1 ton of aluminum dross, the average flow rate of the inlet and outlet lines is 55 to 60 m ³ /Hr.

In addition, the aluminum dross treatment method according to another aspect of the present invention includes a mixing step (S1) of mixing aluminum dross and a carbon component, adding air to the mixture to react, and at the same time adjusting the air input amount to control the temperature and react. In the first reaction step (S2), which is maintained to produce a product containing a solid compound, sodium salt and hydrogen chloride, hydrogen chloride generated in the first reaction step and an iron (Fe) component are reacted to produce iron chloride, and dissolved in water to form an iron chloride solution A method of treating aluminum dross for recovering solid compounds, sodium salts and iron chloride from aluminum dross, including a second reaction step (S3) of separating them, and a combustion step (S4) of burning the exhaust gas generated in the second reaction step to be.

In the present invention, the chlorine component contained in the aluminum dross can be removed and used as a raw material for cement, and the removed chlorine component can be recovered as an iron chloride solution and used as a precipitant for wastewater treatment.

The mixing step (S1) is a step of mixing carbon components such as aluminum dross and coke, and the carbon component is added as much as the Na content in the aluminum dross, for example, 1.0 to 1.0 to 100 parts by weight of the aluminum dross. This is a step of mixing 3.0 parts by weight. When the carbon component is mixed in excess of 3.0 parts _{by weight, there is a problem in that the amount of CO 2} generated is too large, and when it is mixed in less than 1.0 parts by weight, there is a problem in that the sodium (Na) component that does not participate in the reaction remains.

The first reaction step (S2) is a step of generating a product containing a solid compound, sodium salt and hydrogen chloride by adding air to the mixture to react, and at the same time adjusting the air input amount to control the temperature and maintain the reaction, It is a step of first reacting by controlling the input amount of the reaction temperature to 300 to 800 ℃. When the reaction temperature exceeds 800°C, there is a problem of deterioration due to overheating of the equipment and excessive equipment cost, and when the reaction temperature is less than 300°C, there is a problem that the practicality is lowered due to the low reaction rate.

The reaction time is controlled within the range of 10 to 120 minutes depending on the reaction temperature.

The input amount of air is 20 to 60 m ³ /Hr, and it is forcibly input by pressing through a nozzle. Since the first reaction step mainly uses the heat of oxidation of aluminum and auxiliary heat of oxidation of carbon, there is no need to input external energy to maintain the reaction except for external energy to initially start the reaction.

The second reaction step (S3) is a step of reacting hydrogen chloride (HCl) and iron (Fe) components generated in the first reaction step to produce iron chloride and dissolving it in water to separate it into an iron chloride solution. The iron (Fe) component includes an iron (Fe) component containing _{Fe metal or Fe 2} O ₃ , and it is preferable to use an iron component in the form of _{Fe 2} O _{3 .}

The iron (Fe) component is mixed in an amount of 2 to 10 parts by weight based on 100 parts by weight of aluminum dross. When the iron component is mixed in excess of 10 parts by weight, there is a problem that the purification is not well, and when it is mixed in less than 2 parts by weight, there is a problem that it does not react with HCl and is discharged as an exhaust gas, and this exhaust gas is a cause of environmental pollution There is a problem.

In addition, in the second reaction step (S3), when the hydrogen chloride (HCl) and iron (Fe) components generated in the first reaction step are reacted, the iron chloride solution obtained by the reaction is mixed together and the iron chloride solution finally obtained is concentrated. can do it

The combustion step (S4) is a step of removing the risk of explosion due to combustible gas by burning the generated exhaust gas. Initially, the temperature is raised enough to cause an oxidation reaction by ignition, and then the internal heat sources (C, Al) are burned. while maintaining the combustion temperature.

In the present invention, since the oxidation heat of aluminum contained in the dross is used, there is no need to input external energy, and since the separated chlorine is also recovered and used as a useful component called iron chloride, an eco-friendly, pollution-free aluminum dross recycling method is provided.

Features, structures, effects, etc. exemplified in each of the above-described embodiments may be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

Claims (5)

a first reactor capable of generating hydrogen chloride gas by introducing aluminum dross, a carbon component, and water;
a second reactor for preparing an iron chloride solution by introducing hydrogen chloride gas, an iron component, and water generated from the first reactor; and
A device for treating aluminum dross comprising a; a combustor including an ignition device for combusting the exhaust gas generated from the second reactor.
According to claim 1,
The first reactor is provided with an aluminum dross inlet and a carbon component inlet, and a flow control valve and nozzle through which air for temperature control of the first reactor flows is provided,
The first reactor is equipped with a water inlet line at the bottom to wash the sodium salt generated in the first reactor to discharge the sodium salt solution, and a scraper to discharge the solid mixture generated in the first reactor Aluminum dross processing unit.
According to claim 1,
The second reactor is provided with a hydrogen chloride inlet line, an iron component inlet line and a water inlet line transferred from the first reactor,
An apparatus for treating aluminum dross, characterized in that it comprises a line for circulating the solution discharged from the lower portion of the second reactor back to the upper portion of the second reactor.
4. The method of claim 3,
The second reactor is in a form in which the upper part is divided,
The water inlet line is provided in a form that can be sprayed in two branches from the upper part of the second reactor, so that the hydrogen chloride inlet line side and the circulation line side are respectively sprayed.
According to claim 1,
The combustor burns hydrogen in the flue gas transferred from the second reactor, converts it into water, and discharges the aluminum dross processing apparatus.

Images