A resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum

Abstract

A resistance furnace for high-temperature treatment of waste cathode carbon blocks of electrolytic aluminum, with a rectangular furnace body structure, including a furnace bottom, a furnace wall, a furnace head, a furnace tail, a furnace slot cover, a furnace shell, a condensation zone cover and an exhaust gas collection and treatment device; the furnace wall and the furnace shell are fixedly arranged along the length direction of the furnace bottom, including two furnace walls and two furnace shells, a furnace slot is formed between the two furnace walls, and the two furnace shells are respectively arranged on the outside of the furnace slot, and respectively constitute the exhaust gas condensation zone on both sides of the furnace slot with the two furnace walls; exhaust hole structures are respectively provided on the furnace shells of the two exhaust gas condensation zones on both sides of the furnace slot, and the exhaust gas collection and treatment device of the exhaust gas condensation zone is installed through the exhaust holes. The beneficial effect is that it can meet the use requirements of high-temperature harmless treatment of waste cathode carbon blocks of electrolytic aluminum, and treat the harmful gases volatilized in the waste cathode carbon blocks of electrolytic aluminum to avoid environmental pollution.

Description

Technical Field

[0001] The invention belongs to the field of solid hazardous material treatment, and specifically relates to a treatment device and a production process for waste cathode carbon blocks in the electrolytic aluminum industry. Background Art

[0002] Waste cathode carbon blocks from aluminum electrolysis are hazardous wastes from the dismantling of cathode tanks during maintenance of aluminum electrolysis plants. They are dangerous because they contain a large amount of soluble fluorides and cyanides, such as sodium fluoride, sodium fluoroaluminate, calcium fluoride, sodium cyanide, etc. Therefore, waste cathode carbon blocks from aluminum electrolysis cannot be disposed of at will.

[0003] There are currently three treatment methods: landfill, water dissolution and high temperature. Landfill is the most commonly used method, but the soluble fluoride and cyanide contained in the landfilled aluminum cathode waste will pollute the underground soil and groundwater due to factors such as rain and sun, and the volatile gas will be transferred by wind to pollute the atmosphere. The water dissolution method is to separate fluoride and cyanide from the carbon powder by crushing, grinding and then dissolving in water, and then classify and treat it, which can effectively reduce pollution. However, the carbon powder after water dissolution still contains a certain proportion of fluoride and cyanide that are insoluble in water, and finally becomes hazardous waste. The high temperature method is to crush the aluminum cathode waste carbon block and continue to heat it at high temperature until the cyanide and fluoride are completely volatilized, and finally the remaining carbon block can be graphitized and reused, which not only effectively treats the aluminum cathode waste carbon block, but also turns waste into treasure and reuses it. However, the high-temperature method of treating the waste cathode carbon blocks of electrolytic aluminum requires heating the temperature to above 1700℃ to completely volatilize cyanide and fluoride. The common high-temperature calcination furnace body cannot withstand such a high temperature and cannot control the harmful gases volatilized by heating. Therefore, there is currently no effective heating device that can fully heat the waste cathode carbon blocks of electrolytic aluminum and recycle the volatile gases. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that waste cathode carbon blocks of electrolytic aluminum are difficult to heat using a high temperature method, and to provide a resistance furnace that can continuously perform high temperature heating on waste cathode carbon blocks of electrolytic aluminum and effectively recover harmful gases.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to use a high-temperature resistance furnace to carry out high-temperature treatment of electrolytic aluminum waste cathode carbon blocks, arrange air holes on the furnace wall of the high-temperature resistance furnace, arrange a cooling jacket outside the furnace wall to form a closed exhaust gas condensation zone between the furnace shell and the furnace wall, and arrange a collection and treatment device capable of extracting harmful exhaust gases in the exhaust gas condensation zone. The specific technical solution is as follows.

[0006] The resistance furnace for high-temperature treatment of waste cathode carbon blocks of electrolytic aluminum of the present invention has a rectangular furnace body structure, including a furnace bottom, a furnace wall, a furnace head, a furnace tail, a furnace trough cover, a furnace shell, a condensation zone cover and an exhaust gas collection and treatment device; the furnace bottom is arranged along the length direction, and the furnace wall and the furnace shell are fixedly arranged along the length direction of the furnace bottom, including two furnace walls and two furnace shells, a furnace trough is formed between the two furnace walls, and the two furnace shells are respectively arranged on the outside of the furnace trough, and respectively constitute the exhaust gas condensation zones on both sides of the furnace trough with the two furnace walls; the furnace head and the furnace tail are fixedly arranged at the front and rear ends of the furnace trough, and the furnace trough cover is installed on the top to form a seal for the furnace trough; the condensation zone cover is installed on the top of the exhaust gas condensation zone to form a seal for the exhaust gas condensation zone; exhaust hole structures are respectively provided on the furnace shells of the two exhaust gas condensation zones on both sides of the furnace trough, and the exhaust gas collection and treatment devices of the exhaust gas condensation zones are installed through the exhaust holes.

[0007] The furnace bottom is a concrete structure, and a furnace shell mounting groove is arranged along the outer side. The furnace bottom is sealed and mounted with the furnace shell through the furnace shell mounting groove.

[0008] The furnace wall is a refractory brick wall structure, on which air holes are evenly distributed, and the height of the air holes is set according to the layout height of the electrolytic aluminum waste cathode carbon blocks in the furnace tank.

[0009] A layer of refractory brick substrate is laid on the furnace bottom in the furnace tank.

[0010] Electrode blocks are respectively installed on the furnace head and the furnace tail.

[0011] A spray device is installed at the bottom of the furnace tank cover.

[0012] The furnace shell is a jacket structure, the interior of which is filled with cooling water, a circulating water pipe communicating with the interior is arranged on the outside of the furnace shell, and a circulating pump is installed on the circulating water pipe.

[0013] The circulating water pipe of the furnace shell is arranged in the vertical direction, and the cooling water in the furnace shell circulates in the up and down directions through the circulating water pipe.

[0014] The furnace wall and the furnace shell are provided with a circle of water seal grooves along the top, and the furnace wall and the furnace shell are sealed and installed with the furnace groove cover and the condensation zone cover through the water seal grooves.

[0015] The beneficial effects of the present invention are as follows: the waste cathode carbon blocks of electrolytic aluminum can be rendered harmless by utilizing the method of high-temperature treatment, thereby achieving the purpose of treating high-risk waste; at the same time, the graphitization degree of the waste cathode carbon blocks of electrolytic aluminum can be greatly improved through the treatment method of electric calcination, so that the waste cathode carbon blocks of electrolytic aluminum can be made into graphite raw materials, thereby realizing the resource utilization of the waste cathode carbon blocks of electrolytic aluminum; during the high-temperature treatment process, the harmful gases volatilized in the waste cathode carbon blocks of electrolytic aluminum can be collected and treated in time, thereby avoiding environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] AttachedFigure 1 It is a schematic diagram of the planar layout structure of the furnace body of the present invention;

[0017] Attached Figure 2 It is a schematic diagram of the transverse cross-sectional structure of the furnace body of the present invention;

[0018] In the attached figure:

[0019] Furnace bottom 1, furnace shell mounting groove 11, refractory brick base 12, furnace wall 2, air vents 21, coal 22, electrolytic aluminum waste cathode carbon blocks 23, furnace head 3, furnace tail 4, furnace tank cover 5, spray device 51, furnace shell 6, exhaust holes 61, circulating water pipe 62, circulating pump 63, condensation zone cover 7, tail gas collection and treatment device 8, water seal tank 9. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be described in detail below in conjunction with embodiments.

[0021] Example 1

[0022] As attached Figure 1-2 As shown, the resistance furnace for high-temperature treatment of waste cathode carbon blocks of electrolytic aluminum of the present invention has a rectangular furnace body structure, including a furnace bottom 1, a furnace wall 2, a furnace head 3, a furnace tail 4, a furnace trough cover 5, a furnace shell 6, a condensation zone cover 7 and an exhaust gas collection and treatment device 8; the furnace bottom 1 is arranged along the length direction, the furnace wall 2 and the furnace shell 6 are fixedly arranged along the length direction of the furnace bottom 1, including two furnace walls 2 and two furnace shells 6, a furnace trough is formed between the two furnace walls 2, and the two furnace shells 6 are respectively arranged on the outside of the furnace trough, and respectively constitute the exhaust gas condensation zones on both sides of the furnace trough with the two furnace walls 2; the furnace head 3 and the furnace tail 4 are fixedly arranged at the front and rear ends of the furnace trough, and the furnace trough cover 5 is installed on the top to form a seal for the furnace trough; the condensation zone cover 7 is installed on the top of the exhaust gas condensation zone to form a seal for the exhaust gas condensation zone; exhaust holes 61 structures are respectively provided on the furnace shells 6 of the two exhaust gas condensation zones on both sides of the furnace trough, and the exhaust gas collection and treatment device 8 of the exhaust gas condensation zone is installed through the exhaust holes 61.

[0023] The furnace bottom 1 is a concrete structure, and a furnace shell mounting groove 11 is arranged along the outer side. The furnace bottom 1 is sealed and mounted with the furnace shell 6 through the furnace shell mounting groove 11 .

[0024] The furnace wall 2 is a refractory brick wall structure, on which air holes 21 are evenly distributed. The height of the air holes 21 is set according to the layout height of the electrolytic aluminum waste cathode carbon blocks in the furnace tank.

[0025] A layer of refractory brick substrate 12 is laid on the furnace bottom 1 in the furnace tank.

[0026] Electrode blocks are installed on the furnace head 3 and the furnace tail 4 respectively.

[0027] A spray device 51 is installed at the bottom of the furnace tank cover 5.

[0028] The furnace shell 6 is a jacket structure, and is filled with cooling water. A circulating water pipe 62 communicating with the interior is arranged on the outside of the furnace shell 6, and a circulating pump 63 is installed on the circulating water pipe.

[0029] The circulating water pipe 62 of the furnace shell 6 is arranged in the vertical direction, and the cooling water in the furnace shell 6 circulates in the up and down directions through the circulating water pipe 62 .

[0030] The furnace wall 2 and the furnace shell 6 are provided with a circle of water seal grooves 9 along the top, and the furnace wall 2 and the furnace shell 6 are sealed and installed with the furnace groove cover 5 and the condensation area cover 7 through the water seal grooves 9.

[0031] Example 2

[0032] The application of the resistance furnace for high-temperature treatment of electrolytic aluminum waste cathode carbon blocks in the harmless treatment process of electrolytic aluminum waste cathode carbon blocks of the present invention comprises the following steps:

[0033] A fabric method:

[0034] 1) using coal 22 to lay a cushion layer on the refractory brick base 12 in the furnace tank;

[0035] 2) Laying the electrolytic aluminum waste cathode carbon block 23 on the cushion layer in the furnace tank, laying it along the middle position of the furnace tank from the furnace head 3 to the furnace tail 4, leaving a certain distance of gap between the electrolytic aluminum waste cathode carbon block 23 and the furnace wall 2 on both sides of the furnace tank;

[0036] 3) Fill the gap between the aluminum electrolysis waste cathode carbon block 23 and the furnace wall 2 on both sides of the furnace tank with coal 22 to the same height as the aluminum electrolysis waste cathode carbon block 23;

[0037] 4) using coal 22 to lay another covering layer on top of the electrolytic aluminum waste cathode carbon block 23;

[0038] B Furnace body seal:

[0039] 1) Install the furnace groove cover 5 along the water seal groove 9 on the top of the two furnace walls 2 to seal the furnace groove;

[0040] 2) Install the condensation zone cover 7 along the water seal groove 9 on the top of the furnace wall 2 and the furnace shell 6 to seal the exhaust gas condensation zone;

[0041] C Calcination:

[0042] 1) The electrode blocks of the furnace head 3 and the furnace tail 4 are powered on, and the temperature of the electrolytic aluminum waste cathode carbon block 23 begins to rise under the action of power. As the temperature reaches a certain height, harmful gases such as cyanide and fluoride in the electrolytic aluminum waste cathode carbon block 23 begin to volatilize;

[0043] 2) After the harmful gases such as cyanide and fluoride in the electrolytic aluminum waste cathode carbon block 23 are completely volatilized, the calcination temperature of the electrolytic aluminum waste cathode carbon block 23 is further increased to complete graphitization;

[0044] D Waste gas separation:

[0045] 1) During calcination, the circulating pump 63 of the furnace shell 6 drives the cooling water in the jacket of the furnace shell 6 to circulate from top to bottom along the circulating water pipe 62, so that the furnace shell 6 is kept at a low temperature, and the low-temperature furnace shell 6 is used to solidify harmful gases such as cyanide and fluoride in the exhaust gas condensation zone;

[0046] 2) During the calcination period, the exhaust gas collection and treatment device 8 is used to extract the harmful exhaust gas and solidified flocculent waste in the exhaust gas condensation zone for centralized harmless treatment. During the exhaust gas collection and treatment device 8, negative pressure is generated in the exhaust gas condensation zone, and the negative pressure is used to accelerate the discharge of harmful gases such as cyanide and fluoride in the furnace tank;

[0047] E Discharge:

[0048] After calcination, the tail gas collection and treatment device 8 continues to operate for a period of time to ensure that the harmful gases in the furnace tank and the exhaust gas condensation area are completely extracted, and then the furnace tank is cooled by the spray device 51 on the furnace tank cover 5. After cooling, the furnace tank cover 5 is removed, and the coal 22 in the furnace tank and the processed electrolytic aluminum waste cathode carbon blocks 23 are cleared out using a discharging tool.

Claims

1. A resistance furnace for high-temperature treatment of waste cathode carbon blocks of electrolytic aluminum, with a rectangular furnace structure, characterized by: The invention comprises a furnace bottom (1), a furnace wall (2), a furnace head (3), a furnace tail (4), a furnace groove cover (5), a furnace shell (6), a condensation zone cover (7) and an exhaust gas collection and treatment device (8); the furnace bottom (1) is arranged along the length direction, the furnace wall (2) and the furnace shell (6) are fixedly arranged along the length direction of the furnace bottom (1), and comprises two furnace walls (2) and two furnace shells (6), a furnace groove is formed between the two furnace walls (2), and the two furnace shells (6) are respectively arranged on the outer sides of the furnace groove and are connected to the two furnace walls (2 ) respectively constitute the exhaust gas condensation areas on both sides of the furnace trough; the furnace head (3) and the furnace tail (4) are respectively fixedly arranged at the front and rear ends of the furnace trough, and a furnace trough cover (5) is installed on the top to form a seal for the furnace trough; a condensation area cover (7) is installed on the top of the exhaust gas condensation area to form a seal for the exhaust gas condensation area; exhaust holes (61) are respectively provided on the furnace shells (6) of the two exhaust gas condensation areas on both sides of the furnace trough, and an exhaust gas collection and treatment device (8) of the exhaust gas condensation area is installed through the exhaust holes (61); The furnace bottom (1) is a concrete structure, and a furnace shell mounting groove (11) is arranged along the outer side. The furnace bottom (1) is sealed and mounted with the furnace shell (6) through the furnace shell mounting groove (11); The furnace shell (6) is a jacket structure and is filled with cooling water. A circulating water pipe (62) communicating with the interior is arranged on the outside of the furnace shell (6), and a circulating pump (63) is installed on the circulating water pipe.

2. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 1, characterized in that: The furnace wall (2) is a refractory brick wall structure, on which air holes (21) are evenly distributed, and the height of the air holes (21) is set according to the layout height of the electrolytic aluminum waste cathode carbon blocks in the furnace tank.

3. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 1, characterized in that: A layer of refractory brick base (12) is laid on the furnace bottom (1) in the furnace tank.

4. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 1, characterized in that: Electrode blocks are respectively installed on the furnace head (3) and the furnace tail (4).

5. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 1, characterized in that: A spray device (51) is installed at the bottom of the furnace tank cover (5).

6. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 5, characterized in that: The circulating water pipe (62) of the furnace shell (6) is arranged in the vertical direction, and the cooling water in the furnace shell (6) circulates in the up and down directions through the circulating water pipe (62).

7. The resistance furnace for high temperature treatment of waste cathode carbon blocks of electrolytic aluminum as claimed in claim 1, characterized in that: The furnace wall (2) and the furnace shell (6) are provided with a circle of water seal grooves (9) along the top, and the furnace wall (2) and the furnace shell (6) are sealed and installed with the furnace groove cover (5) and the condensation zone cover (7) through the water seal groove (9).

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