EP0103130A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of producing carbonaceous blocks in a tunnel type furnace
Assignee: Polynt SpA
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Filing: 1983-08-01
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Granted: —
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Expires: 2003-08-01
Abstract
Abstract This invention relates to a method of producing carbonaceous blocks, and more particularly to a method of manufacturing anodes for the electrolytic reduction of aluminium, consisting of coating said blocks with an antioxidizer protective powder and calcining them while being passed through a tunnel type furnace in an oxidizing atmosphere in conformity with thermal conditions whereby, as said blocks reach a temperature of 200-600 °C at which they release volatile organic substances, said oxidizing atmosphere has a temperature of at least 550 °C; thus, complete combustion of the volatile substances is accomplished in said furnace to yield gases which are free of said volatile organic substances, and wherein said blocks later attain a final baking temperature of up to about 1,200°C.
Inventors
- 👤 Alessandro Di Cio'
- 👤 Goffredo Buttazzoni
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 10:40
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/08; C25C3/12; C25C3/125; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528; C04B35/532
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
110 words
A method of calcining carbonaceous bodies particularly useful in the manufacture of anodes for electrolytically reducing aluminum, characterized in that said bodies are coated with an antioxidizer protective powder and calcined while being passed through a tunnel type furnace in an oxidizing atmosphere in conformity with thermal conditions wherein, upon said bodies achieving a temperature of 200-600°C Whereat said bodies release volatile organic substances, said oxidizing atmosphere has a temperature of at least 550°C, whereby complete combustion of said volatile substances takes place within said furnace to yield gases free of said volatile organic substances, and Wherein said bodies later achieve a final baking temperature of up to about 1200°C.
Claim 2
Independent Claim
110 words
A method of calcining carbonaceous bodies particularly useful in the manufacture of anodes for electrolytically reducing aluminum, characterized in that said bodies are coated with an antioxidizer protective powder and calcined while being passed through a tunnel type furnace in an oxidizing atmosphere in conformity with thermal conditions wherein, upon said bodies achieving a temperature of 200-600°C Whereat said bodies release volatile organic substances, said oxidizing atmosphere has a temperature of at least 550°C, whereby complete combustion of said volatile substances takes place within said furnace to yield gases free of said volatile organic substances, and Wherein said bodies later achieve a final baking temperature of up to about 1200°C.
Claim 3
Dependent Claim
40 words
A method according to Claim 1, characterized in that said oxidizing atmosphere has, during said step of combustion of volatile substances, an oxygen content of at least 2% by volume referred to the total volume of the dry gas present.
Claim 4
Dependent Claim
47 words
A method according to either Claim 1 or 2, characterized in that said oxidizing atmosphere in said zone of combustion of said volatile substances has a temperature of at least 550°C and a concentration of oxygen, referred to the dry gases, of at least 2% by volume.
Claim 5
Independent Claim
53 words
A method according to any of Claims 1 to 3, characterized in that the heat application rate for said carbonaceous bodies in said temperature range from 200°C to 600°0 varies from about 10'C/hour to about 45 8 C/hour on the external surface thereof, and from about 10°C/hour to 40°C/hour on the inside thereof.
Claim 6
Independent Claim
32 words
A method according to any of the preceding claims, characterized in that said carbonaceous bodies are transported through said tunnel type furnace in countercurrent relationship with the gas flow through said furnace.
Claim 7
Independent Claim
61 words
A method according to any of Claims 1 to 4, characterized in that said carbonaceous bodies are caused to move through said furnace upon exiting said zone of combustion of said volatile organic substances in equicurrent relationship with the gas flow through said furnace, and then, as far as the outlet of said furnace, in countercurrent relationship with said gas flow.
Claim 8
Independent Claim
43 words
A method according to any of the preceding claims, characterized in that the temperature and the oxygen concentration of said oxidizing atmo sphere are regulated by injecting cool air at ambient tem - perature into said zone of combustion of volatile organic substances.
Claim 9
Independent Claim
38 words
A method according to any of Claims 1 to 6, characterized in that the temperature and the oxygen concentration of said oxidizing atmosphere is regulated by injecting preheated air into said zone of combustion of volatile organic substances.
Claim 10
Dependent Claim
37 words
A method according to Claim 8, characterized in that said preheated air is derived from said oxidizing atmosphere of the furnace at an area of said furnace where said atmosphere undergoes preheating by contacting said carbonaceous bodies.
Claim 11
Independent Claim
60 words
A method according to any of Claims 7 to 9, characterized in that said injection of regulating air is effected in a perpendicular direction to the general gas flow direction through said furnace to thus induce turbulent flow conditions effective to rapidly make the temperature levels homogeneous across a transverse section through said zone of combustion of volatile organic substances.
Claim 12
Independent Claim
45 words
A method according to any of the preceding claims, characterized in that said carbonaceous bodies, as coated with said protective powder, are accommodated in porous wall muffles allowing the outflowing of said volatile organic substances therethrough and the combustion thereof externally to the muffle walls.
References Cited (Backward Citations)
No citation records indexed.
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