CN102747375A - Paint remover for internal and external surface paint films of aluminum pop can and use method - Google Patents

Abstract

The invention relates to a paint remover for internal and external surface paint films of an aluminum pop can and a use method. The paint remover is composed of nitric acid, hydrofluoric acid and water. The paint remover is prepared by mixing nitric acid, hydrofluoric acid and water of certain proportion uniformly. The paint removal method includes: immersing aluminum pop can fragments resulted from breaking and magnetic separation into the paint remover for 10-300 seconds, then filtering the fragments and putting them into water for stirring cleaning, filtering the removed paint films, and drying the obtained aluminum alloy fragments.

Description

A kind of varnish remover and method of use of aluminium pop can surfaces externally and internally paint film

Technical field

The present invention relates to the technology that metal material surface carries out chemical paint removal.

Background technology

Annual more than 2,400 hundred million of the pop cans that consume in the whole world beginning of this century, wherein the overwhelming majority is an aluminium pop can, more than 400 ten thousand tons in annual approximately consumption aluminium.Carry out the recovery of pop can and obtain secondary aluminum and alloy thereof, the not only economic environmental protection but also the energy that economizes on resources, recovery homogenous quantities aluminium and alloy thereof are compared with electrolytic aluminum and approximately can be practiced thrift 97% energy.

Aluminium ring pull end can body material is No. 3004 duraluminums, and a jar bottom material is No. 5182 duraluminums, and the draw ring material is No. 5082 duraluminums.In order effectively to improve the ability of acidproof, the alkaline-resisting and organic solvent-resistant of pop can, the pop can surfaces externally and internally of being everlasting all applies one deck paint film to improve its solidity to corrosion, increases its aesthetic feeling simultaneously.General can body, jar end, the draw ring of adopting separately reclaims when reclaiming pop can, and also three kinds of handlebars are handled directly No. 3004 duraluminums of preparation or prepare burden as other duraluminum of back simultaneously.The recovery duraluminum of aluminium pop can is the higher duraluminum of a mass, and developed country's recovery utilization rate is higher, can be worth and obtain bigger utilization reclaiming the new pop can of aluminium pop can processing back direct production.This aluminium pop can of domestic general recovery becomes the lower duraluminum of class with crucible for smelting, the big heavy discount of utilization ratio.Aluminium pop can reclaims and comprises that mainly pretreatment system is like fragmentation, magnetic separation, separation dedusting etc., paint removal system, melting systems such as melting, insulation etc., casting system.The quality of wherein paint removal system handles and cost are to influence pop can to reclaim one of key factor of aluminium quality and utilization ratio, must give enough attention and solution rationally.

At present the paint removal method of some metals mostly can be applicable to the paint removal of pop can, but exist prescription complicated, contain volatile noxious solvent, treatment time long, handle shortcomings such as not thorough.Removing mainly contains following several method to pop can surfaces externally and internally paint film: (1) sand papering paint removal: can remove enamelled coating with sand papering, mode is flexible, pollution is few, but clearance is unstable, is not suitable for scale operation.(2) hot paint removal method: method is simple, good manufacturability, abroad mainly in this way.With the pop can pre-treatment good after, put into rotary kiln, be heated to about 540 ℃ organic hydrocarbon paint film pyrolysis and reach the purpose of paint removal.But exist equipment to have high input, energy consumption is high, and aluminium is prone to oxidizing fire, produces shortcomings such as obnoxious flavour.(3) organic solvent paint removal: often contain large amount of organic such as methylene dichloride, trichloromethane, ester class, phenols, paraffin etc. in this type varnish remover; Mostly water insoluble; Aftertreatment is inconvenient, have shortcomings such as volatile, inflammable, poisonous, and the paint removal rate is influenced obviously by solvent strength.(4) vitriol oil paint removal: utilize the vitriol oil to aluminium and alloy passivation thereof, characteristics such as the organism in the paint film and oxide dissolution, reaction are reached the purpose of paint removal, its complex process.The vitriol oil requires sealing when handling, do not reach the purpose of passivation after thinning, can react with base material on the contrary, causes the reduction of the recovery.

In Chinese patent CN200910069633.7 and CN200810152559.0; Prepared a kind of special varnish remover of forming by methylene dichloride, formic acid or trifluoroacetic acid and water to the pop can paint film; But contain volatile deleterious solvent in this varnish remover; And the treatment time is longer, and some drug price is more expensive.

Summary of the invention

The purpose of this invention is to provide one varnish remover and the method for use of aluminium pop can surfaces externally and internally paint film.

The present invention is one The varnish remover and the method for use of aluminium pop can surfaces externally and internally paint film,Aluminium pop can surfaces externally and internally paint film varnish remover, per-cent meter by volume, its component is: nitric acid 10% ~ 80%, hydrofluoric acid 10% ~ 90%, water 0 ~ 30%.

The method of use of aluminium pop can surfaces externally and internally paint film varnish remover the steps include:

(1) by the described composition of claim 1, preparation aluminium pop can surfaces externally and internally paint film varnish remover;

(2) the aluminium pop can fragment behind the crushing-magnetic selection was only soaked in varnish remover 10 seconds ~ 300 seconds;

(3), filter the paint film that comes off with debris filter and pour stirring and washing in the water into;

(4) the duraluminum fragment of removing paint film is refiltered and carry out drying treatment.

Usefulness of the present invention is water-fast dilution, and pop can surfaces externally and internally paint film is all demonstrated good paint removal and stripping effect, and processing speed is very fast, and little to the base material corrosion, the duraluminum recovery is high.This varnish remover preparation is simple, cheap, and repeating utilization factor is high, is fit to the continuous or semicontinuous processing of various scales under the room temperature.

Embodiment

For realizing above-mentioned purpose, the technical scheme that the present invention adopted is:

This varnish remover is made up of nitric acid, hydrofluoric acid, water, and each component volume percent is: mass percent concentration is the nitric acid 10% ~ 80% of 50%-70%, and mass percent concentration is greater than 40% hydrofluoric acid 10% ~ 90%, water 0 ~ 30%;

With nitric acid, hydrofluoric acid and the water of above-mentioned certain share, promptly get varnish remover after mixing.At room temperature; The aluminium pop can fragment of crushing-magnetic selection is immersed in the above-mentioned varnish remover after 10 seconds-300 seconds; Filter out fragment and immerse and be stirred to paint film in the water and matrix is peeled off fully; Topple over and fall upper strata buoyant paint film, then filter out the duraluminum fragment after the paint removal, carry out waiting until after the drying treatment next step melt processed again.

Embodiment one:

Each component of varnish remover is prepared by following volume percent: nitric acid 80%, hydrofluoric acid 10%, water 10%; Under the room temperature, the aluminium pop can fragment is soaked in the above-mentioned varnish remover, adventitia was peeled off fully in about 30 seconds, and inner membrance was peeled off fully in about 240 seconds.

Embodiment two:

Each component of varnish remover is prepared by following volume percent: nitric acid 58%, hydrofluoric acid 25%, water 17%; Under the room temperature, the aluminium pop can fragment is soaked in the above-mentioned varnish remover, adventitia was peeled off fully in about 60 seconds, and inner membrance was peeled off fully in about 240 seconds.

Embodiment three:

Each component of varnish remover is prepared by following volume percent: nitric acid 36%, hydrofluoric acid 50%, water 14%; Under the room temperature, the aluminium pop can fragment is soaked in the above-mentioned varnish remover, adventitia was peeled off fully in about 60 seconds, and inner membrance was peeled off fully in about 270 seconds.

Embodiment four:

Each component of varnish remover is prepared by following volume percent: nitric acid 17%, hydrofluoric acid 75%, water 8%; Under the room temperature, the aluminium pop can fragment is soaked in the above-mentioned varnish remover, adventitia was peeled off fully in about 60 seconds, and inner membrance was peeled off fully in about 300 seconds.

Embodiment five:

Each component of varnish remover is prepared by following volume percent: nitric acid 25%, and hydrofluoric acid 75%, water 0% under the room temperature, is soaked in the aluminium pop can fragment in the above-mentioned varnish remover, and adventitia was peeled off fully in about 10 seconds, and inner membrance was peeled off fully in about 300 seconds.

Claims (3)

1. aluminium pop can surfaces externally and internally paint film varnish remover, per-cent meter by volume, its component is: nitric acid 10% ~ 80%, hydrofluoric acid 10% ~ 90%, water 0 ~ 30%.

2. the inside and outside paint film varnish remover of aluminium pop can according to claim 1, it is characterized in that: the mass percent concentration of said nitric acid is 50%-70%, and the mass percent concentration of hydrofluoric acid is greater than 40%.

3. the method for use of aluminium pop can surfaces externally and internally paint film varnish remover the steps include:

(1) by the described composition of claim 1, preparation aluminium pop can surfaces externally and internally paint film varnish remover;

(2) the aluminium pop can fragment behind the crushing-magnetic selection was only soaked in varnish remover 10 seconds ~ 300 seconds;

(3), filter the paint film that comes off with debris filter and pour stirring and washing in the water into;

(4) the duraluminum fragment of removing paint film is refiltered and carry out drying treatment.