CN1297066A

CN1297066A - Coating material for side of aluminium electrolyzer

Info

Publication number: CN1297066A
Application number: CN 99123061
Authority: CN
Inventors: 钟群标
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-17
Filing date: 1999-11-17
Publication date: 2001-05-30

Abstract

A coating material for sides of aluminium electrolyzer is prepared from silicon carbide, carbon, SiO2, Al2O3, silicon nitride, Si, calcium oxide and chromium oxide, and features high anticorrosion and anti-oxidizing power. It can increase the service life of electrolyzer, prevent side leakage and raise current efficiency.

Description

The coated material of side of aluminium electrolyzer

The present invention relates to a kind of coated material of side of aluminium electrolyzer.

Existing domestic and international side of aluminium electrolyzer material mostly adopts high-ash carbon materials at present.This material very easily is subjected to the burn into oxidation of ionogen (sodium aluminum fluoride-aluminum oxide) fused salt and metallic aluminium in secular hot operation process.Cause the side wall composite material early damage, and make sidepiece produce runout, cause when serious and stop groove, influenced the ordinary production of electrolyzer, also reduced the work-ing life of electrolyzer.Usually be 4-5 the work-ing life of electrolyzer.High-ash carbon materials has higher electroconductibility, produces horizontal current and sidepiece electric leakage in electrolytic process, and these all seriously affect the raising of current efficiency.When silicon carbide brick was used for aluminum cell side, owing to need between brick and the brick bond with binding agent, therefore, adhesive segment was exactly a weak link, easily causes fused salt to spill from the agglutinating slit, and this also is to limit one of major reason that it promotes the use of.

Purpose of the present invention just provides a kind of anticorrosive, anti-oxidant, improves the work-ing life of electrolyzer, prevents the sidepiece electric leakage, improves the coated material of the side of aluminium electrolyzer of current efficiency.

The object of the present invention is achieved like this: a kind of coated material of side of aluminium electrolyzer, the weight part of its chemical ingredients is: silicon carbide 600-800, carbon 5-40, silica 1 0-40, aluminium sesquioxide 5-40, silicon nitride 60-140, silicon 15-35, chromic oxide 1-4.

The coated material of side of aluminium electrolyzer, the weight part of its chemical ingredients is: silicon carbide 650-750, carbon 10-30, silicon-dioxide 20-30, aluminium sesquioxide 10-30, silicon nitride 80-140, silicon 20-30, chromic oxide 1-3.

The coated material of side of aluminium electrolyzer, its chemical ingredients optimum weight part is: silicon carbide 700, carbon 20, silicon-dioxide 23, aluminium sesquioxide 20, silicon nitride 100, silicon 25, chromic oxide 2.5.

Manufacture process: one, carborundum aggregate and the carbonaceous material with various size compositions stirs fully.Two, various powders are mixed, and stir.Three, the above-mentioned material remix that stirs together, add an amount of water again after waiting to stir and stir.Four, smear before, need the cleaning of sidewall carbon brick surface totally, coat the binding agent of skim then, it is suitable to require to smear uniform thickness.Five, with the applying material that stirs on carbon piece surface, smearing thickness can be operated as required.Six, after above-mentioned work is finished, need just can to put into production use being not less than under 10 ℃ the condition natural Health preservation 3-7 days.

This material is compared with silicon carbide brick, and their physical and chemical index is basic identical, all has very strong potential resistance to electrolyte contamination fused salt, the corrosion of metallic aluminium, and higher mechanical properties makes it anti-ly wash away, not take place peeling phenomenon.Compare with high-ash carbon materials and also to have higher heat conductivity and resistivity, the use that these performances all help improving electrolyzer is received the order and is reduced horizontal current, stops the sidepiece electric leakage effectively, can improve current efficiency.

The thermal expansivity of this coated material and the thermal expansivity of high-ash carbon materials are basic identical, so two kinds of materials combine by binding agent, binding agent and two kinds of material sintering are in aggregates, can not produce separation phenomenon.

This coated material is used for aluminium cell, can form an integral body, does not have the silicon carbide brick weak link.Simultaneously, coated material can also be vulcanized the damaged position of sidepiece takes place, this material also has the volume density higher than silicon carbide brick, can stop fused salt to penetrate into material internal effectively and binding agent reacts, so all are higher than silicon carbide brick in its use range and effect and work-ing life.

The difference of this material and silicon carbide brick maximum is: it does not need high-pressure molding and carry out roasting under the condition of special high temperature (1400 ℃--2400 ℃).Production technique is simple, and cost is low.Moisture in the material can be discharged in the roasting and starting process of electrolyzer, finishes the sintering of material simultaneously, forms stable material.

Embodiment:

Weigh raw material in following ratio:

Silicon carbide 700g, carbon 20g, silicon-dioxide 23g, aluminium sesquioxide 20g, silicon nitride 100g, silicon 25g, chromic oxide 2.5g.

Manufacture process: one, carborundum aggregate and the carbonaceous material with various size compositions stirs fully.Two, all the other powders are mixed, and stir.Three, the material remix that stirs in above-mentioned, two together, the water that adds 50-70g after waiting to stir again stirs.Four, smear before, need the cleaning of electrolyzer sidewall carbon brick surface totally, coat the binding agent of skim then, this binding agent should contain the composition of carbon, silicon-dioxide, sodium oxide, carbon paste for example, it is suitable to require to smear uniform thickness.Five, with the applying material that stirs on carbon piece surface, smearing thickness can be operated as required.Six, after above-mentioned work is finished, need just can to put into production use being not less than under 10 ℃ the condition natural Health preservation 3-7 days.The body of this coated material is close＞2.7g/cm ³, refractoriness 〉=1790 ℃ are at 110 ℃ of its compressive strength 〉=40MPa, at 1000 ℃ of its compressive strength 〉=55MPa, at 110 ℃ of its folding strength 〉=7MPa, at 1000 ℃ of its folding strength 〉=10MPa.

Although the present invention has been described and has quoted as proof specific examples, concerning the training technique personnel of this area, only otherwise leave that the spirit and scope of the present invention can be done various variations or correction is obvious.

Claims

1. side of aluminium electrolyzer coated material, it is characterized in that: the weight part of its chemical ingredients is: silicon carbide 600-800, carbon 5-40, silica 1 0-40, aluminium sesquioxide 5-40, silicon nitride 60-140, silicon 15-35, chromic oxide 1-4.

2. according to the side of aluminium electrolyzer coated material described in the claim 1, it is characterized in that: the weight part of its chemical ingredients is: silicon carbide 650-750, carbon 10-30, silicon-dioxide 20-30, aluminium sesquioxide 10-30, silicon nitride 80-140, silicon 20-30, chromic oxide 1-3.

3. according to the side of aluminium electrolyzer coated material described in the claim 1, it is characterized in that: its chemical ingredients optimum weight part is: silicon carbide 700, carbon 20, silicon-dioxide 23, aluminium sesquioxide 20, silicon nitride 100, silicon 25, chromic oxide 2.5.