CN113621839A

CN113621839A - Aluminum alloy production casting process based on energy conservation and environmental protection

Info

Publication number: CN113621839A
Application number: CN202011124466.4A
Authority: CN
Inventors: 刘宗意
Original assignee: Hunan One Thousand Sources Aluminum Co ltd
Current assignee: Hunan One Thousand Sources Aluminum Co ltd
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2021-11-09

Abstract

The invention discloses an aluminum alloy production casting process based on energy conservation and environmental protection, which relates to the field of aluminum alloy production and comprises the following steps: the method comprises the following steps: preparing an aluminum alloy raw material; step two: smelting, namely adding a bottom net made of a diamond material and a diamond block for heat conduction into a furnace body for smelting; step three: after smelting is finished, refining and degassing are carried out, hydrogen carried in the smelting is removed, and the generation of pores is reduced; step four: then pouring the alloy into a mould for cooling, adding a heat exchange mechanism outside the mould, preheating and preserving heat of the smelting furnace by using heat energy of heat exchange, and then carrying out a casting procedure. The invention realizes heat exchange and heating of alloy raw materials by using diamond, thereby reducing the smelting temperature of the later metal and reducing the energy consumption of the smelting furnace, thereby achieving the purpose of energy saving, and the heat exchange link can accelerate smelting, shorten the starting time of the smelting furnace and achieve the purpose of energy saving again.

Description

Aluminum alloy production casting process based on energy conservation and environmental protection

Technical Field

The invention relates to the field of aluminum alloy production, in particular to an aluminum alloy production casting process based on energy conservation and environmental protection.

Background

The aluminum alloy is an alloy which is based on aluminum and added with a certain amount of other alloying elements, is one of light metal materials, has the common characteristics of aluminum, has the specific characteristics of certain alloys due to the difference of the types and the quantity of the added alloying elements, has the density of 2.63-2.85 g/cm, has higher strength, specific strength close to high alloy steel, specific stiffness superior to steel, good casting performance and plastic processing performance, good electric conduction and heat conduction performance, good corrosion resistance and weldability, can be used as a structural material, and has wide application in aerospace, aviation, transportation, architecture, electromechanics, lightening and daily necessities.

The existing aluminum alloy production casting process can be smelted by various methods, a coreless induction furnace, a groove induction furnace, a crucible furnace, a reflection type open hearth furnace (using natural gas or fuel oil for combustion), a resistance furnace and an electrothermal radiation furnace are commonly used, the types of furnace materials are wide, high-quality pre-alloyed ingot can be used from the furnace materials composed of low-grade waste materials, however, the direct smelting casting can cause the problems of high furnace body casting temperature and large energy consumption, and the molten aluminum is also easily influenced by other adverse effects even under the condition of being more suitable for smelting and pouring: under the high temperature condition, along with the increase of hydrogen that dissolves in the melt that results in of the absorption of hydrogen, the existence of hydrogen can cause the emergence of gas pocket, and the quality of gas pocket meeting greatly reduced aluminum alloy to reduce the market price of aluminum alloy.

Disclosure of Invention

The invention aims to: in order to solve the problems that the existing aluminum alloy production casting process can be smelted by various methods, a coreless induction furnace, a groove induction furnace, a crucible furnace, a reflection type open hearth furnace (using natural gas or fuel oil for combustion), a resistance furnace and an electrothermal radiation furnace are commonly used, the types of furnace materials are wide, high-quality pre-alloyed ingot can be used from the furnace materials which are specially composed of low-grade waste materials, however, the direct smelting casting can cause the problems of high furnace body casting temperature and high energy consumption, and the molten aluminum is easily influenced by other adverse effects even under the condition of being more suitable for smelting and pouring: under the high temperature condition, along with the increase of hydrogen that dissolves in the melt that leads to of absorption of hydrogen, the existence of hydrogen can cause the emergence of gas pocket, and the quality of gas pocket meeting greatly reduced aluminum alloy to reduce the market price problem of aluminum alloy, provide the aluminum alloy production casting process based on under energy-concerving and environment-protective.

In order to achieve the purpose, the invention provides the following technical scheme: the aluminum alloy production casting process based on energy conservation and environmental protection comprises the following steps:

the method comprises the following steps: preparing an aluminum alloy raw material;

step two: smelting, namely adding a bottom net made of a diamond material and a diamond block for heat conduction into a furnace body for smelting;

step three: after smelting is finished, refining and degassing are carried out, hydrogen carried in the smelting is removed, and the generation of pores is reduced;

step four: then pouring the alloy into a mould for cooling, adding a heat exchange mechanism outside the mould, preheating and preserving heat of the smelting furnace by using heat energy of heat exchange, and then carrying out a casting procedure.

Preferably, the preparation of the aluminum alloy raw material in the first step includes:

s1: raw materials required by batching, including aluminum bonds, magnesium bonds, titanium agents, aluminum-strontium alloys, waste aluminum materials and the like, must have chemical components and can be used according to the requirements of the alloy on the components;

s2: the used raw materials are clean, dry, free of mud, oil and dirt and corrosion;

s3: the proportion of the waste aluminum material and the primary aluminum is based on the premise of ensuring the temperature of the aluminum liquid;

s4: during the calculation of the ingredients, the magnesium is accurately metered, the magnesium is blended according to the middle limit and the upper limit, the silicon is blended according to the middle limit and the lower limit, and the titanium and the strontium take the actual yield and the temperature during the addition into consideration.

Preferably, smelting in the second step, and adding a bottom net made of diamond and a diamond block for heat conduction into a furnace body for smelting, wherein the furnace body for smelting comprises:

s1: the electric heating furnace, a new furnace and a furnace after overhaul are adopted to be dried according to the process rules strictly, the furnace which needs to be put into production for use after overhaul is adopted, and the furnace drying time is determined according to the specific conditions;

s2: cleaning a new furnace, a large furnace and a medium-sized furnace after repair, and washing the furnace by using pure aluminum or A356 alloy waste;

s3: charging, namely protecting a hearth and reducing metal burning loss, processing industrial silicon and waste aluminum materials, adding aluminum and large aluminum blocks, adding holmium and magnesium before refining, and adding strontium after chlorine salt refining and uniformly stirring by using a magnetic cable stirrer;

s4, installing a bottom net made of diamond at the bottom of the furnace body, wherein the bottom net can be paved in multiple layers, the upward height is 0-30cm, a certain amount of diamond blocks are placed on the bottom net at the top end after the paving is finished, the diameter of the diamond blocks is 20-55cm, if necessary, a vibrating motor can be additionally arranged on one side of the furnace body, a preheating air port is arranged on one side of the furnace body, and a heat insulation sleeve is additionally arranged on the outer side of the furnace body.

Preferably, the smelting in the second step comprises:

s1: heat exchange is carried out by utilizing the residual heat energy after the previous batch of smelting, after the heat exchange in the step of die-backing, the furnace body is preheated by utilizing the heat energy, the preheating temperature can reach 200-;

s2: when the alloy in the furnace body is smelted, the diamond is heated at the same time, and when the alloy is smelted, a covering agent is added to prevent oxidation and burning loss;

s3: at the smelting temperature, taking a sample for spectral analysis, and determining the magnesium adding amount, the silicon supplementing amount and the holmium and strontium adding amounts according to the result;

s4: after the smelting is finished, pouring out the alloy material in the molten state for refining, wherein the alloy material in the molten state passes through the bottom net, and the diamond blocks cannot be melted and cannot pass through the bottom net because the diamond blocks do not reach the melting temperature;

s5: and introducing a heat preservation medium outside the furnace, preserving heat of the residual diamond blocks and the diamond bottom net in the furnace, wherein the diamond blocks and the bottom net can exchange heat for the next batch of alloy raw materials, and starting a vibration motor when necessary to ensure that the diamond blocks and the alloy raw materials are fully mixed for heat exchange so as to reduce the smelting temperature of the next batch of alloy raw materials.

Preferably, after the smelting in the third step is finished, the smelting is refined, and the refining comprises:

s1: adding a required refining agent into a refining furnace, covering the refining furnace, opening a refining tank switch, introducing nitrogen, wherein the refining agent is formed by basically adding active adsorbents such as cryolite and the like and gas-making agents such as hexachloroethane and the like by using a ternary flux, an electromagnetic stirring technology is adopted in production, nitrogen is used as a carrier, when the refining agent is sprayed out from an iron refining pipe, the refining agent can be inserted into the refining furnace and slowly moves 2-3 times at each position in the furnace, when all the fluxes in the refining tank are completely sprayed out, the refining pipe is firstly drawn out from the aluminum liquid, and then the nitrogen is closed;

s2: the refining time is prolonged along with the increase of the amount of the molten aluminum, the powder feeding speed is controlled by opening a switch at the bottom of the refining tank, and the principle is that powder is sprayed out within the refining time range;

s3: the end of the refining pipe is preferably inserted into the molten aluminum to a depth of 2/3, and moves left and right without breaking the furnace wall and the furnace bottom to prevent the pipe from being blocked;

s4: the refining temperature is 710-;

s5: the overturning height of the aluminum liquid is controlled by controlling the nitrogen pressure, and the principle is that the overturning height is preferably smaller under the condition of not blocking a pipe, and is preferably controlled to be below 15 cm;

s6: then the smelted body is kept still for a certain time, generally 15-25 minutes, which is not suitable to exceed 30 minutes, and the excessive time of keeping still can promote the gas content of the smelted body to increase and reduce the productivity of the furnace; when the standing time is too long, refining should be performed again.

Preferably, after the smelting in the third step is finished, the smelting is refined and is subjected to 'degassing', hydrogen carried in the smelting is removed, and the generation of pores is reduced, wherein the 'degassing' comprises the following steps:

s1: during the refining process, a refining degasifier is added into a refining body to produce a large amount of gas, then the hydrogen atoms dissolved in the aluminum liquid are diffused to bubbles by utilizing the partial pressure principle, and when the bubbles float to the surface of the aluminum liquid, the bubbles are broken and the hydrogen escapes into the atmosphere due to the light specific gravity of the bubbles, so that the aim of removing the hydrogen is fulfilled;

s2: meanwhile, a method of rapid or high-pressure solidification is adopted, so that the solubility of gas in the aluminum alloy is improved, and the gas is promoted to be delayed or not separated out, thereby achieving the purpose of eliminating pinholes;

s3: after refining the refined body, when the refined body is poured into a mould for cooling, when the refined body becomes a plate solid, the metal fluorine and beryllium in a molten state can be inverted into the mould, so that the metal fluorine and beryllium are in contact with the alloy and do not contact with the surface of the alloy, the metal fluorine and beryllium can form a compact oxide film on the surface of the aluminum, the diffusion speed of hydrogen into aluminum liquid or the aluminum alloy is reduced, the aluminum alloy is protected, and pores caused by the contact of the metal aluminum and the hydrogen in the casting process are avoided;

s4: meanwhile, the environment of alloy casting is controlled, the alloy is dry and clean, and excessive water vapor is not suitable.

Preferably, in the fourth step, the alloy is poured into a mold for cooling, a heat exchange mechanism is additionally arranged outside the mold, heat energy of heat exchange is used for preheating and heat preservation of the smelting furnace, and then the casting process comprises the following steps:

s1: the heat exchange adopts 600 plus 700 red copper coil pipes, heat energy is transported to the interior of the smelting furnace in a sealed heat-insulating pipeline after heat exchange, and part of the heat energy enters a heat-insulating sleeve on the outer side of the smelting furnace to insulate the heat energy;

s2: in the casting process, the casting temperature is 680-710 ℃, and the water pressure is 0.5-1.0Kg/mm 2;

s3: after casting, the chute and other casting tools should be cleaned and maintained in time for the next use.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, through the arranged smelting, the bottom net made of diamond and the diamond block for heat conduction are added into the furnace body for smelting, the alloy is poured into the mold for cooling, the heat exchange mechanism is additionally arranged on the outer side of the mold, and the smelting furnace is preheated and insulated by heat energy of heat exchange, so that the heat exchange and heating of the alloy raw material by using the diamond are realized, the smelting temperature of the metal in the later batch is reduced, the energy consumption of the smelting furnace is reduced, the energy-saving purpose is achieved, the smelting can be accelerated in the heat exchange link, the starting time of the smelting furnace is shortened, and the energy-saving purpose is achieved again;

2. according to the invention, after the arranged smelting is finished, the aluminum alloy is refined and is subjected to degassing, hydrogen carried in the aluminum alloy is removed, the generation of air holes is reduced, the air holes exist because the aluminum alloy has serious oxidation and gas suction tendencies, the aluminum alloy directly has the serious oxidation and gas suction tendencies with furnace gas or because the aluminum alloy has the serious oxidation and gas suction tendencies in the smelting process, the air holes are directly formed with the furnace gas or gases easy to absorb in the smelting process, the most common gas is hydrogen, and the hydrogen is taken out by adopting different means in the refining link, so that the disappearance of the air holes can be ensured to a certain extent, the quality of the aluminum alloy is improved, and the market price is improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations and positional relationships shown, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. The following describes an embodiment of the present invention based on its overall structure.

The aluminum alloy production casting process based on energy conservation and environmental protection comprises the following steps:

The preparation of the aluminum alloy raw material in the first step comprises the following steps:

According to the invention, through the arranged smelting, the bottom net made of diamond and the diamond block for heat conduction are added into the furnace body for smelting, the alloy is poured into the mold for cooling, the heat exchange mechanism is additionally arranged on the outer side of the mold, and the smelting furnace is preheated and insulated by heat energy of heat exchange, so that the heat exchange and heating of the alloy raw material by using the diamond are realized, the smelting temperature of the metal in the later batch is reduced, the energy consumption of the smelting furnace is reduced, the energy-saving purpose is achieved, the smelting can be accelerated in the heat exchange link, the starting time of the smelting furnace is shortened, and the energy-saving purpose is achieved again.

Smelting in the second step, adding a bottom net made of diamond and a diamond block for heat conduction into a furnace body for smelting, wherein the furnace body for smelting comprises:

In the present invention, if the furnace washing is not carried out, a certain amount of gas such as a newly built furnace lining, a refractory material of the furnace, a mold and the like can be brought in due to the existence of a large amount of oil and burden, for example, tools and the like which contact with the gas such as hydrogen, oxygen, water vapor, carbon dioxide and the like, and it usually takes several days or weeks until the chemically bound hydrogen is sufficiently released from the binder.

The smelting in the second step comprises the following steps:

In the invention, the melting point of the diamond is 3350 ℃, the general melting temperature of the metal aluminum is 700-800 ℃, and the diamond has good heat conduction effect and good heat exchange and heating effects on the next batch of metal.

After the smelting in the third step is finished, refining the molten steel, wherein the refining comprises the following steps:

s4: the refining temperature is 710-;

The nitrogen and refining agents of the present invention are maintained at sufficient purity and dryness.

After the smelting in the third step is finished, refining the molten steel, and performing degassing to remove hydrogen carried in the molten steel and reduce the generation of pores, wherein the degassing comprises the following steps:

In the invention, for electric furnace smelting used by most smelting plants at present, the furnace gas mainly contains hydrogen, and in addition to the method for removing hydrogen, measures such as rapid smelting, shortening of high-temperature retention time, strengthening of prevention measures in wet seasons and the like are required during smelting of aluminum alloy.

Pouring the alloy into the mould in step four and cooling, the heat transfer mechanism is established to the mould outside to preheat and keep warm the smelting furnace with the heat energy of heat transfer, then carry out the casting process and wherein include:

s3: after casting, the chute and other casting tools are cleaned and maintained in time for next use, the residue beating shovel, the casting mold and the splitter plate are well preheated, the casting speed is adjusted to the maximum, and aluminum ingots in the casting mold are cleaned.

The casting preparation in the present invention requires checking the mechanical, electrical, and cooling water systems for health.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. Aluminum alloy production casting process based on under energy-concerving and environment-protective, characterized by includes:

2. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: the preparation of the aluminum alloy raw material in the first step comprises the following steps:

3. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: smelting in the second step, adding a bottom net made of diamond and a diamond block for heat conduction into a furnace body for smelting, wherein the furnace body for smelting comprises:

4. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: the smelting in the second step comprises the following steps:

5. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: after the smelting in the third step is finished, refining the molten iron, wherein the refining comprises the following steps:

s4: the refining temperature is 710-;

6. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: after the smelting in the third step is finished, refining the molten steel, degassing, removing hydrogen carried in the molten steel, and reducing the generation of pores, wherein the degassing comprises the following steps:

7. The energy-saving and environment-friendly aluminum alloy production and casting process based on the claim 1 is characterized in that: in the fourth step, the alloy is poured into a mold for cooling, a heat exchange mechanism is additionally arranged outside the mold, heat energy of heat exchange is used for preheating and heat preservation of the smelting furnace, and then the casting process comprises the following steps: