CN102719680A

CN102719680A - Purification method for light metal and alloy melt thereof

Info

Publication number: CN102719680A
Application number: CN2012102072819A
Authority: CN
Inventors: 龙思远; 范超
Original assignee: Chongqing Shuolong Science and Technology Co Ltd
Current assignee: Chongqing Shuolong Science and Technology Co Ltd
Priority date: 2012-06-21
Filing date: 2012-06-21
Publication date: 2012-10-10

Abstract

A purification method for light metal and alloy melt thereof belongs to the field of metallurgy. By means of the structure design of a gas purification chamber, the method realizes the following purposes: (1) dead corners in the purification chamber are eliminated, so that any spaces in the purification chamber can be filled up with gas bubbles; (2) melt flow is guided to pass through the purification chamber from the top down in a direction opposite to the direction of purifying gas bubble flow; ultimately, the gas bubble flow which moves in the opposite direction can be in sufficient contact with the melt flow, and therefore the effect of continuously and efficiently purifying flowing melt is achieved.

Description

The purifying method of a kind of light metal and alloy melt thereof

Technical field

What the present invention relates to is the purifying treatment method of a kind of light metal and alloy melt thereof, and the continuous purification treatment process of particularly a kind of magnesium, aluminium alloy melt belongs to field of metallurgy.

Background technology

It is a requisite link that cleaning molten is handled for any light metal and the alloy course of processing thereof, and the quality of purifying treatment directly has influence on whether obtain high-quality product.Current light metal and alloy melt purifying treatment thereof mainly are according to the swim the whole bag of tricks of theoretical developments of bubble; It is through being blown into Purge gas to light metal and alloy melt thereof; Form bubble; For the removal of hydrogen in the melt, be through the partial pressure difference between melt and the bubble, make the constantly diffusion and remove to bath surface in bubble of hydrogen in the melt with bubble floating; And for the removal of the non-metallic inclusion in the melt, then be through contacting with inclusion in the bubble floating process, it is bigger than melt to the wettability of inclusion, thus the dross inclusion adsorption come-up is brought surperficial slag blanket into and is removed.Present bubble flotation process is to grow up 20th century 70, the eighties mostly, and according to the difference that feeds the gas mode, the bubble flotation process can be divided into single pipe method, porous insufflation, stationary nozzle method and rotary blowing method.

Literature search through to prior art is found; Shanghai Communications University develops " purifying aluminium alloy melt method " referring to number of patent application: 0510026593.X; This refining plant top uses the method for rotary blowing that Purge gas is blown in the molten aluminium, and the bottom of device is installed gas permeable brick Purge gas is blown into melt simultaneously.The Shanghai College of Mechanical Engineering is developed " a kind of vertex angle combined blowing type aluminum melt degassing method and device " referring to number of patent application: 0910044935.9; This refining plant is blown into molten aluminium with Purge gas from swivel arrangement, and Purge gas also is blown into molten aluminium from the peripheral inlet port of refining plant simultaneously.Shanghai Communications University develops " magnesium melt purifying device " referring to number of patent application: 0910048993.9, and this refining plant adopts rotation air blast that the magnesium melt is carried out purifying treatment.Wenxi County, Shanxi silver light magnesium industry ltd develops " magnesium alloy large-sized smelting system " referring to number of patent application: 0701065235.6, and this refining plant adopts single tube that the magnesium melt is carried out blowing purification and handles.

These technology have certain advantage with respect to traditional purifying method, but also there is certain limitation in they, mainly show: the most volume of these refining plants is very big; Be square mostly; When melt was carried out purifying treatment, the central zone air content of refining plant was higher, and periphery and corner region air content seldom or at all do not have Purge gas; The melt of refining plant periphery and corner areas can not contact with the bubble of sufficient amount like this, causes these regional decontamination effect improvings relatively poor.The melt of these refining plants is that bottom or middle part from device flows into mostly in addition, and contacts fully inadequately in the bubble floating process with melt, reach effect preferably, purifying treatment chronic, and the consumption of Purge gas can be very big.Some method on the basis of rotary blowing, from the bottom or periphery be blown into Purge gas, though can improve the distribution situation of bubble to a certain extent, also can cause the refining plant structure to become complicated, the Purge gas consumption is big, cost rises.Adopt the mode of single tube to be blown into gas in addition, bubble size is bigger, and ascent rate can cause purification efficiency not high than comparatively fast.

Summary of the invention

The present invention is directed to above-mentioned deficiency of the prior art, the method for the continuous high-efficient purifying treatment of a kind of light metal and alloy melt thereof is provided, low cost, high-level efficiency, increase substantially the purity of light metal and alloy melt thereof.

For realizing above-mentioned purpose, the technical scheme that the present invention adopts is: the present invention eliminates dead angle in the decontamination chamber through the chamber cleaning gas structure Design, guarantees that bubble can be full of the space of appointing in the decontamination chamber; With the direction opposite with the purified gas burble, the guiding melt-flow is passed through the decontamination chamber from top to down; The bubble flow of finally guaranteeing inverse motion fully contacts with melt-flow, reaches the effect that continuous high-efficient purifies the overcurrent melt.

Light metal and alloy melt thereof are through the chute inflow gas decontamination chamber on top, decontamination chamber; The top-down motion of melt-flow; The decontamination chamber is blown into Purge gas simultaneously, forms bubble, and bubble flow becomes inverse motion with melt-flow from bottom to top; After the purifying treatment, melt flows to subsequent technique by the outlet at bottom of chamber cleaning gas.

The present invention compared with prior art has remarkable advantages, and its difference is with advantage:

(1) chamber cleaning gas design rational in infrastructure.The conventional employed refining plant of purifying treatment decontamination chamber size is generally bigger, and is mostly square, and during purifying treatment, the amount of some zone (like corner region) Purge gas seldom or does not at all have, and the effect of the cleaning molten that these are regional is very undesirable.For these zones are purified, usually adopt speed that increases rotor or the method that increases the flow velocity of Purge gas, but this can cause the fluctuation of bath surface, cause melt to inhale the increase of hydrogen and oxide inclusion quantity; Perhaps adopt the method that prolongs the clarification time, but this can increase gas consumption, make to purify the cost rising.The method that adopts bottom or middle increase blowing device to blow in addition, though can improve these area decontamination effects to a certain extent, it is complicated that the structure of refining plant becomes, but also can strengthen the consumption of Purge gas.The present invention carries out appropriate design with the gas sweetening cell structure, has fundamentally eliminated the dead angle area that can not purify, and guarantees that bubble can be full of the space of appointing in the decontamination chamber; Simple in structure; Can reach good decontamination effect improving under than the slow speed of revolution or less Purge gas consumption, it is low to purify cost.

(2) melt-flow and bubble flow inverse motion.Under this mode of motion; The probability of melt and bubble hit improves greatly, has increased the surface in contact of melt and Purge gas, receives the drag effect of melt in the bubble uphill process; Thereby prolong the time that they stop in melt; Make more gas and impurity by bubble capture, on float to bath surface and be able to remove, thereby improved purification efficiency.Under the equal melt flow condition, reach identical decontamination effect improving, the Purge gas consumption that is consumed is lower, and cost is lower.

(3) rational melt flow.Because the chamber cleaning gas volume is less relatively, get into that the indoor melt of gas sweetening is few the unit time, the part has reduced the flow of melt, and under the equal purification condition (like air input, speed of rotation etc.), the bubble of waiting until is more tiny, thereby improves purification efficiency.

In sum, the present invention compared with prior art has significant advantage, and bigger advantage has important techniques meaning and economic implications for the purification of light metal and alloy melt thereof, has a extensive future, and is worthy of popularization especially.

Description of drawings

Fig. 1, Fig. 2 are principle of work synoptic diagram of the present invention.Wherein, Fig. 1 is blown into the Purge gas mode for adopting rotary blowing, and Fig. 2 is blown into the Purge gas mode for adopting the bottom gas permeable brick.

Embodiment

In conjunction with content of the present invention following examples are provided:

These embodiment are used to explain the present invention, rather than limitation of the present invention, under design prerequisite of the present invention, to the simple modifications of the inventive method, all belong to the scope of requirement protection of the present invention.

Embodiment 1:

As shown in Figure 1, the chute of molten aluminium by top flow in the decontamination chamber, the molten aluminium temperature is 750 ℃; Liquid level is 500 ㎜, per hour handles molten aluminium 700 ㎏, and molten aluminium moves from top to down; Purge gas (99.99% drying nitrogen); Be blown into the refining plant from rotary nozzle, the rotary blowing rotor rotating speed is 300 rev/mins, and gas flow is 0.2m ³/ h, gaseous tension position 0.1MPa, Purge gas obtains tiny bubble under the effect of rotary blowing, from down and motion fully contacts with molten aluminium, absorb in the molten aluminium hydrogen be mingled with, bubble floating is to liquid level and with they removals.Molten aluminium after the purification flows to next process through the outlet of below.

Its result of implementation is following: the hydrogen content of molten aluminium is at the melt inlet place: 0.35ml/100gAl, and the molten aluminium hydrogen content is 0.05 ml/100gAl in the exit, and hydrogen addition rate reaches about 85%, and the metal gas consumption ratio is 0.25L/ ㎏.

Embodiment 2:

As shown in Figure 2, the chute of magnesium melt by top flow in the decontamination chamber, the magnesium melt temperature is 710 ℃; Liquid level is 500 ㎜; Per hour handle magnesium melt 700 ㎏, the magnesium melt moves from top to down, Purge gas (dry pure argon); Gas permeable brick is blown into the refining plant from the bottom, and gas flow is 0.22m ³/ h, gaseous tension position 0.1MPa, bubble be from down and motion fully contacts with the magnesium melt, absorb in the magnesium melt hydrogen be mingled with, bubble floating is to liquid level and with they removals.The outlet of magnesium melt through the below after the purification flows to next process.

Its result of implementation is following: the hydrogen content of magnesium melt is at the melt inlet place: 0.43ml/100gMg, and magnesium melt hydrogen content is 0.13ml/100gMg in the exit, and hydrogen addition rate reaches about 75%, and the metal gas consumption ratio is 0.29L/ ㎏.

Claims

1. the melt continuous purification method of light metal and alloy thereof is characterized in that, through the chamber cleaning gas structure Design, eliminates dead angle in the decontamination chamber, guarantees that bubble can be full of the space in the decontamination chamber; With the direction opposite with the purified gas burble, the guiding melt-flow is passed through the decontamination chamber from top to down; The bubble flow of finally guaranteeing inverse motion fully contacts with melt-flow, reaches the effect that continuous high-efficient purifies the overcurrent melt.