Ceramet material with gradient function for electrolyzing Al

Abstract

The present invention relates to aluminum electrolysis, and is especially inert ceramet anode. The ceramet material has structure of at least two layers and is rod shaped, plate shaped or cup shaped. The ceramic phase is spinelle type composite oxide; and the metal phase is made of Cu, Ni, Co, Fe, Ag, Pt, Au and other metal or their binary or multiple-element alloy. The composite material with gradient function has excellent comprehensive performance under electrolysis, and the anode of the composite material needs no frequent replacement. Using the composite material of the present invention can alter the electrolytic bath structure, raise production efficiency, lower aluminum ingot producing cost, improve environment, and reduce power consumption.

Description

Technical field:

[0001] This invention relates to aluminum electrolysis, and in particular to cermet inert anodes. Background technique:

[0002] The aluminum electrolysis process takes place in a fluoride salt melt above 900 °C, which requires strict requirements on inert anode materials. The inert anode materials for aluminum electrolysis are mainly three types: metal oxide ceramics, alloy anodes and cermets. Among them, cermets take into account the advantages of strong corrosion resistance of oxide ceramics and good electrical conductivity of metals. However, due to a small amount of metal phase dispersed in the ceramic phase, the cermets studied at home and abroad have poor thermal shock resistance, poor electrical conductivity, difficulty in connecting with metal guide rods, and difficulty in large-scale; Densification, under the conditions of electrolysis, it is easy to cause oxidation and selective corrosion of the metal phase, resulting in slag and shedding of the...

Examples

Embodiment 1

[0021] figure 1 described a round rod-shaped NiFe 2 o 4 The gradient structure of / Cu gradient functional cermet material, which is based on NiFe 2 o 4 It is a ceramic phase, and Cu is a metal phase; it is designed as 11 gradient layers, and the taper angle θ between the side gradient layers 1, 2, 3 and the bottom gradient layers 6, 7, and 8 is 45 degrees; the outer layer 4 and the bottom layer The metal phase Cu content of 9 is 5wt%, and the ceramic phase NiFe 2 o 4 The content is 95wt%; the core 5 cermet contains 50wt% Cu, 50wt% NiFe 2 o 4 ; NiFe made of outer layer 4 and bottom layer 9 2 o 4 / Cu cermet layer respectively through 9 NiFe 2 o 4 / Cu gradient cermet layer transition to NiFe in core 5 2 o 4 / Cu cermet, the metal Cu content of adjacent gradient layers differs by 5wt%.

[0022] The side gradient layer of the material is formed by the centrifugal method, the bottom gradient disc is formed by the lamination method, the round rod-shaped core 5 cermet is f...

Embodiment 2

[0024] figure 2 described a plate-shaped NiFe 2 o 4 - Gradient structure of NiO / Cu-Ni gradient functional cermet material, which adopts NiFe doped with 35wt% NiO 2 o 4 It is a ceramic phase, and Cu-Ni alloy is a metal phase; it is designed as 9 gradient layers, and the taper angle θ between the side gradient layers 1, 2, 3 and the bottom gradient layers 6, 7, and 8 is 45 degrees; the outer layer 4 and the ceramic phase NiFe of the bottom layer 9 2 o 4 -NiO content is 90wt%, metal phase Cu-Ni alloy content is 10wt%, wherein Ni content in the alloy is 20wt%; core 5 is NiFe containing 90wt% Ni 2 o 4 -NiO / Ni cermet; NiFe made of outer layer 4 and bottom layer 9 2 o 4 -NiO / Cu-Ni cermet layers are respectively passed through 7 NiFe 2 o 4 -NiO / Cu-Ni gradient cermet layer transition to NiFe in core 5 2 o 4 -NiO / Ni cermet; the metal phase Cu-Ni alloy content of adjacent gradient layers differs by 10wt%; the Ni content in the metal phase alloy differs by 10wt%.

[0025] Th...

Embodiment 3

[0027] image 3 described a goblet NiFe 2 o 4 -Gradient structure of NiO / Cu-Ni gradient functional cermet material, the cup body 8 is NiFe 2 o 4 -NiO / Cu-Ni cermet material, wherein the ceramic phase is NiFe doped with 35wt% NiO 2 o 4 ; The metal phase is a Cu-Ni alloy containing 15wt% Ni, and the metal phase content is 10wt%; the composition is gradiently changed along the axial direction of NiFe 2 o 4 -NiO / Ni gradient functional cermet connects the conductive rod 1 to the cup body 8; NiFe 2 o 4 -NiO / Ni gradient functional cermet designed as 9 gradient layers; bottom layer 7 ceramic phases NiFe2 o 4 - The content of NiO is 90 wt%; the content of metallic phase Ni is 10 wt%; the ceramic phase NiFe of the top layer 2 2 o 4 -The content of NiO is 10wt%; the content of Ni in the metal phase is 90wt%; 2 o 4 - The NiO / Ni gradient cermet layer transitions to the top 2 cermet layer, and the Ni contents of the metal phases of adjacent gradient layers differ by 10 wt%.

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Technical field:

[0001] This invention relates to aluminum electrolysis, and in particular to cermet inert anodes. Background technique:

[0002] The aluminum electrolysis process takes place in a fluoride salt melt above 900 °C, which requires strict requirements on inert anode materials. The inert anode materials for aluminum electrolysis are mainly three types: metal oxide ceramics, alloy anodes and cermets. Among them, cermets take into account the advantages of strong corrosion resistance of oxide ceramics and good electrical conductivity of metals. However, due to a small amount of metal phase dispersed in the ceramic phase, the cermets studied at home and abroad have poor thermal shock resistance, poor electrical conductivity, difficulty in connecting with metal guide rods, and difficulty in large-scale; Densification, under the conditions of electrolysis, it is easy to cause oxidation and selective corrosion of the metal phase, resulting in slag and shedding of the...

Examples

Embodiment 1

[0021] figure 1 described a round rod-shaped NiFe 2 o 4 The gradient structure of / Cu gradient functional cermet material, which is based on NiFe 2 o 4 It is a ceramic phase, and Cu is a metal phase; it is designed as 11 gradient layers, and the taper angle θ between the side gradient layers 1, 2, 3 and the bottom gradient layers 6, 7, and 8 is 45 degrees; the outer layer 4 and the bottom layer The metal phase Cu content of 9 is 5wt%, and the ceramic phase NiFe 2 o 4 The content is 95wt%; the core 5 cermet contains 50wt% Cu, 50wt% NiFe 2 o 4 ; NiFe made of outer layer 4 and bottom layer 9 2 o 4 / Cu cermet layer respectively through 9 NiFe 2 o 4 / Cu gradient cermet layer transition to NiFe in core 5 2 o 4 / Cu cermet, the metal Cu content of adjacent gradient layers differs by 5wt%.

[0022] The side gradient layer of the material is formed by the centrifugal method, the bottom gradient disc is formed by the lamination method, the round rod-shaped core 5 cermet is f...

Embodiment 2

[0024] figure 2 described a plate-shaped NiFe 2 o 4 - Gradient structure of NiO / Cu-Ni gradient functional cermet material, which adopts NiFe doped with 35wt% NiO 2 o 4 It is a ceramic phase, and Cu-Ni alloy is a metal phase; it is designed as 9 gradient layers, and the taper angle θ between the side gradient layers 1, 2, 3 and the bottom gradient layers 6, 7, and 8 is 45 degrees; the outer layer 4 and the ceramic phase NiFe of the bottom layer 9 2 o 4 -NiO content is 90wt%, metal phase Cu-Ni alloy content is 10wt%, wherein Ni content in the alloy is 20wt%; core 5 is NiFe containing 90wt% Ni 2 o 4 -NiO / Ni cermet; NiFe made of outer layer 4 and bottom layer 9 2 o 4 -NiO / Cu-Ni cermet layers are respectively passed through 7 NiFe 2 o 4 -NiO / Cu-Ni gradient cermet layer transition to NiFe in core 5 2 o 4 -NiO / Ni cermet; the metal phase Cu-Ni alloy content of adjacent gradient layers differs by 10wt%; the Ni content in the metal phase alloy differs by 10wt%.

[0025] Th...

Embodiment 3

[0027] image 3 described a goblet NiFe 2 o 4 -Gradient structure of NiO / Cu-Ni gradient functional cermet material, the cup body 8 is NiFe 2 o 4 -NiO / Cu-Ni cermet material, wherein the ceramic phase is NiFe doped with 35wt% NiO 2 o 4 ; The metal phase is a Cu-Ni alloy containing 15wt% Ni, and the metal phase content is 10wt%; the composition is gradiently changed along the axial direction of NiFe 2 o 4 -NiO / Ni gradient functional cermet connects the conductive rod 1 to the cup body 8; NiFe 2 o 4 -NiO / Ni gradient functional cermet designed as 9 gradient layers; bottom layer 7 ceramic phases NiFe2 o 4 - The content of NiO is 90 wt%; the content of metallic phase Ni is 10 wt%; the ceramic phase NiFe of the top layer 2 2 o 4 -The content of NiO is 10wt%; the content of Ni in the metal phase is 90wt%; 2 o 4 - The NiO / Ni gradient cermet layer transitions to the top 2 cermet layer, and the Ni contents of the metal phases of adjacent gradient layers differ by 10 wt%.

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