CN1931777A - Composite slurry for aluminium electrobath and its production process - Google Patents

Abstract

The composite slurry for aluminum electrobath consists of mixture powder and mixed adhesive solution, the mixture powder consists of sic1, sic2, scale graphite, industrial silica powder and clay powder, and the mixed adhesive solution consists of phenolic resin specially for refractory material, epoxy resin and its curing agent, and industrial alcohol. The composite slurry is filled into crack of aluminum electrobath, has high adhesion strength and may be cured at normal temperature.

Description

Composite sludge for aluminum electrolytic cell and production method thereof

[affiliated technical field]

What the present invention relates to is to improve aluminium cell inner lining material in work-ing life, and composite sludge for aluminum electrolytic cell and production method and specific equipment thereof belong to the high-temperature refractory field.

[technical background]

Aluminium cell work-ing life is by overdetermined perhaps; particularly its performance quality of surveying the wall inner lining material is one of them important factor; they must can anti-aluminium electrolyte chemical erosion, physics corrosion and atmospheric oxidation; also must have enough heat transmission capacities when possessing all these performances, and then on sidewall, set up the ionogen protection that one deck solidifies and stretch one's legs.In electrolytic aluminium plant, make charcoal paste, amorphous carbon piece, graphite charcoal piece firm by ramming, smokeless coal pieces is the most frequently used sidewall inner lining material.The weakness that these materials are fatal is exactly not anti-atmospheric oxidation.Since the sixties in last century, Aluminum circle personage is seeking a kind of side-wall material and production method thereof that can replace carbonaceous material always.The carbofrax material of silicon nitride bonded silicon has now become the up-to-date side-wall material of aluminium cell, the whole world tens tame electrolysis aluminium manufacturers successful Application for many years, China also successful Application the more than ten years, for improving aluminium cell work-ing life, cut down the consumption of energy, vital role has been brought into play in the aspect of boosting productivity.But, because it than higher price, has restricted these goods applying in the electrolysis of aluminum industry.

[summary of the invention]

The purpose of this invention is to provide a kind of silicon carbide brick and side wall carbon block to silicon nitride bonded silicon and all have good wetting property, can stop up its seam preferably, bonding is firm, and thermal shock performance is good, the composite sludge for aluminum electrolytic cell of anti-atmospheric oxidation.

Another object of the present invention provides the production method and the specific equipment of above-mentioned composite sludge for aluminum electrolytic cell.

The objective of the invention is to realize by following technical scheme:

Select the silicon-carbide series material to possess the incomparable advantage of many carbonaceous materials, thereby become the main raw of the first-selection in these materials: above-mentioned aluminum electrolyzing cell used composite sludge is formed by following percentile preparation of raw material:

The starting material particle size diameter requires (mm) useful range

(1), mixed powder is made up of following raw material precentagewise:

1. sic1 expects: 0.2-0.09mm 20～40%

2. sic2 expects :≤0.09 40～60%

3. natural flake graphite :≤0.1 3～5%

4. industrial silica fume :≤0.064 3～5%

5. well as clay fines :≤0.075 5～15%

(2), the hybrid bonding agent solution is made by following raw material precentagewise:

1. the special-purpose resol of refractory materials: 50～60%

2. Resins, epoxy 10～20%

(3) epoxy curing agent 1～5%

4. industrial spirit: 25～35%

(3), composite sludge is made by above two goods precentagewises

1. the mixed powder raw material 68～74%

2. the hybrid bonding agent solution 26～32%

The production method of above-mentioned aluminum electrolyzing cell used composite sludge comprises the following steps:

1. powder is made: at first as requested each powder is ground in the granularity of each regulation, again according to above-mentioned powder proportioning, after sic1 material, sic2 material, natural flake graphite, industrial silica fume, the weighing of well as clay fines difference, pour mixing in the mixer into, become mixed powder standby;

2. binder solution is made: according to the binder solution proportioning, weigh up the special-purpose resol of refractory materials, Resins, epoxy, epoxy curing agent, industrial spirit, all inject in the molten device and stir evenly, become the hybrid bonding agent solution, and standby;

3. above-mentioned standby mixed powder and standby hybrid bonding agent solution are proportionally weighed up, evenly promptly become composite sludge with slurry mixer or hand mixing.

Advantage of the present invention is clearly: this composite sludge cohesive strength is big, anti-oxidant, and the potential resistance to electrolyte contamination erosion performance is strong, good heat conductivity, erosion and the atmospheric oxidation that can resist aluminium electrolyte preferably; Can be in ambient cure, construction has easily improved electrolyzer work-ing life, cuts down the consumption of energy, and boosts productivity; On probation in how tame electrolysis aluminium manufacturer, obtain promising result; Detected result shows, this cohesive strength will be higher than charcoal piece breaking tenacity, guarantee that the electrolytic aluminum groove is when making the charcoal paste firm by ramming, bond line does not ftracture, and comparative example cemented side seam in construction process has fracture and cracking trend, increase the space, thereby strengthened and oxygen, electrolytical touch opportunity, thereby reduced the erosion performance of anti-atmospheric oxidation performance and potential resistance to electrolyte contamination.The compoiste adhering technology had both satisfied the premium properties that silicon nitride products based on silicon carbide demonstrates as side-wall material, be unlikely to too much to improve the manufacturing expense of aluminium cell again, its good constructional feature has obtained international and domestic electrolysis of aluminum researcher and electrolysis of aluminum industry personage's extensive concern, and practicality has proved that comprehensive benefit is remarkable.

[description of drawings]

Fig. 1 is inside and outside big bonding embodiment 1 diagrammatic cross-section of aluminium cell sidewall of the present invention

Fig. 2 is aluminium cell sidewall of the present invention above and below bonding embodiment 2 diagrammatic cross-sections

Among the figure, the 1st, sidewall charcoal piece, the 2nd, composite sludge, the 3rd, the silicon nitride combined silicon carbide plate, the 4th, charcoal is stuck with paste, and the 5th, furnace bottom charcoal piece, the 6th, mould material, the 7th, anti-bleed, the 8th, insulating brick, the 9th, calcium silicate board with microporous, the 10th, pot shell.

[embodiment]

Bonding way between the big face between silicon nitride combined silicon carbide plate 3 and the sidewall charcoal piece 1 as seen from Figure 1: pot shell 10 is shells of aluminium cell, upwards successively lay insulating brick 8, the anti-bleed 7 of dry type and furnace bottom charcoal piece 5 from lowest layer calcium silicate board with microporous 9 in pot shell 10 inner chambers, furnace bottom charcoal piece 5 its outer ends are sticked again and make the inwall of charcoal paste 4 and mould material 6 its outer walls subsides pot shells 10 firm by ramming; Mould material 6 upper walls are vertically established silicon nitride combined silicon carbide plate 3 and sidewall charcoal piece 1 side by side, and sidewall charcoal piece 1 outer wall just is adjacent to the inwall of pot shell 10; The two side of making charcoal paste 4 firm by ramming is connected between the inwall three of furnace bottom charcoal piece 6 outer ends, mould material 5 the inners, silicon nitride combined silicon carbide plate 3; Be composite sludge for aluminum electrolytic cell 2 of the present invention between sidewall charcoal piece 1 and the silicon nitride combined silicon carbide plate 3 in the seam.

Can earlier sidewall charcoal piece 1 be placed in the construction on the construction plate, on its mating surface, coat electrolyzer composite sludge 2 uniformly, on composite sludge 2, glue then and cover silicon nitride combined silicon carbide plate 3, dry back becomes whole precoated plate, integral prefabricated plate is erect put to the mould material 6 of pot shell 10 inboards again; Another method is after assembling sidewall charcoal piece 1 by Fig. 1, again silicon nitride combined silicon carbide plate 3 big faces are smeared composite sludge 2, the silicon nitride combined silicon carbide plate is pasted on sidewall charcoal piece 1 inboard, weigh reality in the hand with wooden mallet or rubber hammer, make charcoal at last firm by ramming and stick with paste, 10 inboard connections in the seam of pot shell also should be smeared composite sludge 2.

As seen from Figure 2 the unique difference of the structure of electrolyzer be sidewall charcoal piece 1 with silicon nitride combined silicon carbide plate 3 between to be connected be to connect up and down, it is the facet bonding, must will weigh reality with the good back of composite sludge 2 bondings in the hand with wooden mallet or rubber hammer between sidewall charcoal piece 1 and the silicon nitride combined silicon carbide plate 3 earlier, make charcoal then firm by ramming and stick with paste, silicon nitride combined silicon carbide plate 3 also should be smeared composite sludge 2 with 10 inboard connections in the seam of pot shell.

Embodiment 1,

The effective ratio of raw material granularity scope

(1) mixed powder

1. sic1 expects: 0.2～0.09mm 20%

2. sic2 expects :≤0.09mm 60%

3. natural flake graphite :≤0.1mm 5%

4. industrial silica fume :≤0.064mm 5%

5. well as clay fines :≤0.075mm 10%

(2) mixed adhesive solution ratio

1. the special-purpose resol of refractory materials: 50%

2. Resins, epoxy 15%

(3) epoxy curing agent 5%

4. industrial spirit: 30%

(3) composite sludge is:

1. the mixed powder raw material 74%

2. the hybrid bonding agent solution 26%

Embodiment 2,

(1) powder proportioning

1. sic1 expects: 0.2-0.09mm 40%

2. sic2 expects :≤0.09mm 40%

3. natural flake graphite :≤0.1mm 5%

4. industrial silica fume :≤0.064mm 5%

5. well as clay fines :≤0.0075 10%

(2) binder solution proportioning

1. the special-purpose resol of refractory materials: 55%

2. Resins, epoxy 15%

(3) epoxy curing agent 3%

4. industrial spirit: 27%

(3) composite sludge is:

1. the mixed powder raw material 70%

2. the hybrid bonding agent solution 30%

Embodiment 3

(1) mixed powder proportioning

1. sic1 expects: 0.2-0.09mm 35%

2. sic2 expects :≤0.09mm 45%

Natural flake graphite :≤0.1mm 5%

4. industrial silica fume :≤0.064mm 5%

5. well as clay fines :≤0.075mm 10%

(2) mixed adhesive solution ratio

1. the special-purpose resol 50% of refractory materials

2. Resins, epoxy 17%

3. epoxy curing agent 3%

4. industrial spirit 30%

(3) composite sludge is:

1. the mixed powder raw material 73%

2. the hybrid bonding agent solution 27%

The foregoing description 3 is as the embodiment of preferred production process:

1. powder is made: weigh up processing back granularity at 35 kilograms in the sic1 of 0.2-0.09mm material, granularity at 45 kilograms in the sic2 material of≤0.09mm, granularity at 5 kilograms of the natural flake graphites of≤0.1mm, granularity at 5 kilograms of the industrial silica fumes of≤0.064mm, granularity 10 kilograms of the well as clay fines of≤0.075mm, pour material in sand mill mixing, conduct is equipped with pulvis in the bag of packing into;

2. binder solution preparation: 50 kilograms in the special-purpose resol of refractory materials, 17 kilograms of Resins, epoxy, 3 kilograms of epoxy curing agents, industrial spirit are mixed into the hybrid bonding agent solution for 30 kilograms in container, standby;

3. 30 kilograms of standby hybrid bonding agent solutions are mixed for 70 kilograms with standby mixing powder, evenly be composite sludge with slurry mixer or hand mixing.

Detected result and effect, the cohesive strength index:

25℃×48h 5.2Mpa， 110℃×24h 11.4Mpa。

1, the comparing result of embodiments of the invention and comparative example and explanation

As can be seen from the above table, cohesive strength of the present invention is higher than the cohesive strength of comparative example far away, the measured result of example: Luo Nai institute is detected greater than 11.4Mpa, and Fedmet company detected result is 1883Ibs/m ²Detected result shows, this cohesive strength will be higher than charcoal piece breaking tenacity, guarantee the electrolytic aluminum groove when making the charcoal paste firm by ramming, bond line does not ftracture, and comparative example cemented side seam in construction process has fracture and cracking trend, increased the space, thereby strengthened and oxygen, electrolytical touch opportunity, thereby reduced the erosion performance of anti-atmospheric oxidation performance and potential resistance to electrolyte contamination, workability and heat conductivility are also not as good as embodiment.

Claims (3)

1, a kind of composite sludge for aluminum electrolytic cell is characterized in that: composite sludge is by mixed powder and mixed adhesive solution composition, the mixed powder raw material account for 68～74% and the hybrid bonding agent solution account for 26～32%; Mixed powder is made by following powder precentagewise: sic120～40%, sic2 40～60%, natural flake graphite 3～5%, industrial silica fume 3～5% and well as clay fines 5～15%; The hybrid bonding agent solution by following solution composition is: the special-purpose resol 50～60% of refractory materials, Resins, epoxy 10～20%, epoxy curing agent 1～5% and industrial spirit 25～35; The granularity requirements of above-mentioned powder is respectively sic1:0.2-0.09mm, sic2≤0.09mm, natural flake graphite≤0.1mm, industrial silica fume≤0.064mm, well as clay fines≤0.075mm.

2, according to the composite sludge of claim 1, it is characterized in that:

Composite sludge is by mixed powder and mixed adhesive solution composition, respectively accounts for per-cent to be: mixed powder raw material 70% and hybrid bonding agent solution 30%; Mixed powder and proportion are: sic1 35%, sic2 45%, natural flake graphite 5%, industrial silica fume 5% and well as clay fines 10%; Mixed adhesive solution composition ratio is: the special-purpose resol 50% of refractory materials, Resins, epoxy 17%, epoxy curing agent 3% and industrial spirit 30%.

3, the production method of a kind of claim 1 or 2 composite sludge may further comprise the steps:

1. powder is made: at first as requested each powder is ground in the granularity of each regulation, again according to above-mentioned powder proportioning, after sic1 material, sic2 material, natural flake graphite, industrial silica fume, the weighing of well as clay fines difference, pour mixing in the mixer into, become mixed powder standby;

2. binder solution is made: according to the binder solution proportioning, weigh up the special-purpose resol of refractory materials, Resins, epoxy, epoxy curing agent, industrial spirit, all inject in the molten device and stir evenly, become the hybrid bonding agent solution, and standby;

3. above-mentioned standby mixed powder and standby hybrid bonding agent solution are proportionally weighed up, evenly promptly become composite sludge with slurry mixer or hand mixing.