Production method capable of being quickly started after shutdown of green anode forming system

Abstract

The invention provides a production method for quickly starting a green anode forming system after shutdown, which comprises the following steps: A, before production, carrying out the following operations: A01, raising the temperature of a liquid asphalt delivery pump and a batching pump to 200-220 DEG C, and raising the temperature of a preheated spiral heating medium oil outlet to 240-260 DEG C; a forming machine mold steam main valve is opened, and the temperature of a green anode forming machine is increased to 100-110 DEG C; a02, enabling the liquid level of the asphalt in the head tank to reach 1.55 m or above, and enabling the temperature of the asphalt to reach 170-190 DEG C; b, a forming system is started for production, and parameters are set as follows: B01, the proportion of the dry aggregate feeding amount to the asphalt feeding amount in unit time is set; b02, a cooling water conveying valve of the powerful cooling machine is in a closed state; and C, producing blocks: continuously removing the high-temperature unqualified paste in the kneading machine until the temperature of the paste in the kneading machine is reduced to 180-190 DEG C, and carrying out molding production. According to the invention, the waste paste discharge time during starting production of green anode molding is greatly reduced, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum smelting, in particular to a method for quickly starting production after shutdown of a green anode forming system. BACKGROUND

[0002] Pre-baked anode is made of petroleum coke and pitch coke as aggregate and coal tar pitch as binder, and is used as anode material for pre-baked aluminum electrolysis cell. This carbon block has been baked and has stable geometric shape, so it is also called pre-baked anode carbon block, and is also called carbon anode for aluminum electrolysis in common practice. The aluminum electrolysis cell using pre-baked anode carbon block as anode is called pre-baked anode electrolysis cell, which is a modern large-scale aluminum electrolysis cell. The production of anode carbon block is processed and made by using petroleum coke as raw material and coal tar pitch as binder through petroleum coke calcination, green anode forming, anode baking and other processes.

[0003] Green anode forming is one of the main core processes of pre-baked anode production, and the main task is to mix and knead the dry aggregate and the binder (liquid pitch) according to a certain ratio to obtain bulk paste, and then to produce plastic deformation under the external force applied by the forming equipment, and finally to become a green anode with certain shape, size and density. The main production process is as follows: the coarse coke, medium coke, fine coke, coarse residue, fine residue and powder material batching bin are discharged according to the set discharge amount, then mixed and heated after passing through the collecting screw conveyor and preheating screw, and then sent to the mixing and kneading machine together with the green scrap discharged according to the set discharge amount. At the same time, the liquid pitch is pumped from the pitch storage tank to the high tank by the pitch conveying pump, and then added to the mixing and kneading machine according to the set flow rate by the pitch batching pump. In the mixing and kneading machine, the aggregate and the pitch are mixed and kneaded, and then cooled to the set temperature by the strong cooling machine. The qualified paste is formed into green anode by the vibration forming machine, and the unqualified paste and waste green anode are discharged from the system.

[0004] After the green anode forming system is shut down for a long time due to planned maintenance, fault elimination and other reasons, about 1 hour of waste paste needs to be discharged before qualified paste is obtained and qualified green anode is produced each time the system is restarted. The long waste paste discharge time increases the cost of anode production. SUMMARY

[0005] The present application aims to provide a method for quickly starting production after shutdown of a green anode forming system, which greatly reduces the waste paste discharge time during starting production of the forming system and reduces the production cost by optimizing the process operation without changing the existing materials and key equipment.

[0006] The technical solution of the present application is as follows: The method for quickly starting production after shutdown of a green anode forming system comprises the following steps: A. Before production, the following operations are performed: A01, the liquid asphalt delivery pump and batching pump is heated to 200-220℃; open the preheating screw heat medium oil inlet and outlet valve, and increase the preheating screw heat medium oil outlet temperature to 240-260℃; open the forming machine mold steam total valve to heat the forming machine mold to 100-110℃; A02, start the liquid asphalt delivery pump to pump the asphalt from the asphalt storage tank into the high tank, and start the asphalt batching pump to return the liquid asphalt to the asphalt storage tank through the asphalt flowmeter pipeline, realize the asphalt self-circulation, and make the liquid level of the high tank asphalt reach 1.55 meters or more, and the asphalt temperature reach 170-190℃; B, start the forming system for production, wherein the parameter setting includes the following steps: B01, set the dry aggregate feeding amount and the asphalt feeding amount ratio per unit time, so that the asphalt feeding amount per unit time is 3-8% higher than that in normal production; B02, the cooling water delivery valve of the strong cooling machine is in a closed state; C, produce blocks: first spray emulsified oil to lubricate the green anode forming machine, then continuously remove the high-temperature unqualified paste in the kneading machine until the paste temperature in the kneading machine is reduced to 180-190℃, then open the cooling water delivery valve of the strong cooling machine, and automatically control the cooling water to send the paste to the green anode forming machine for forming production.

[0007] In the step B, the process of starting the forming system for production includes the following steps: a, start the cooling circulating water system; b, start the asphalt flue gas dust collection system; c, start the batching and kneading conveying system; d, start the forming machine system and enter the automatic operation mode.

[0008] In the step B01, the dry aggregate feeding amount and the asphalt feeding amount ratio per unit time is 1:0.16-0.19.

[0009] In the step B, the parameter setting further includes the following steps: B03, adjust the current of the kneading machine so that the peak current is between 180-200A.

[0010] In the step C, before starting to produce blocks, first spray emulsified oil to lubricate the green anode forming machine.

[0011] The method for quickly starting production after the green anode forming system is stopped further includes the following steps: D, real-time detect the bulk density and appearance of the green anode blocks produced in step C, and when the bulk density and appearance are qualified, reduce the asphalt feeding amount, so that the dry aggregate feeding amount and the asphalt feeding amount ratio per unit time returns to the normal production ratio.

[0012] Preferably, the green anode former is a non-vacuum green anode former.

[0013] The present application has the following advantages: When the present application is used to produce green pre-baked anode products, the amount of waste paste discharged before the system starts production is significantly reduced. According to the calculation of the paste feeding amount of 22 t / h, the amount of unqualified paste discharged is reduced by about 13 t each time according to this method, and the annual profit is increased by 110,000 yuan, which is considerable.

[0014] When the present application is used to produce green pre-baked anode products, the waste paste discharge time is significantly reduced without changing the existing process flow and equipment implementation premise, which reduces the waste paste discharge amount, provides important support for enterprise index optimization and cost reduction and efficiency improvement, and has good application prospect. DETAILED DESCRIPTION

[0015] The present application will be specifically described below in combination with examples. Example 1

[0016] The method for quickly starting production after the green anode forming system stops includes the following steps: A, before production, the following operations are performed: A01, the liquid pitch conveying pump and the batching pump are heated to 200℃, the preheating screw heat medium oil inlet and outlet valves are opened, the preheating screw heat medium oil outlet temperature is heated to 240℃, and the mold steam total valve of the forming machine is opened to heat the mold of the forming machine to 100℃; A02, start the liquid pitch conveying pump to pump the pitch from the pitch storage tank into the high tank, start the pitch batching pump to return the liquid pitch to the pitch storage tank through the pitch flowmeter pipeline, realize the self-circulation of the pitch, make the high tank pitch liquid level reach 1.55, and the pitch temperature reaches 170℃; B, start the forming system for production, and the process of starting the forming system for production includes the following steps: a, start the cooling circulating water system; b, start the pitch flue gas dust collection system; c, start the batching and kneading conveying system; d, start the forming machine system and enter the automatic operation mode.

[0017] The parameter setting includes the following steps: B01, set the dry aggregate feeding amount and the pitch feeding amount ratio to 1:0.16 per unit time; B02, the cooling water conveying valve of the strong cooler is in the closed state; B03, adjust the current of the kneading machine so that the peak current is between 180-190A; C. Production of blocks: first use emulsified oil to spray lubricate the green anode forming machine, then continuously discharge the high-temperature unqualified paste in the kneading machine until the paste temperature in the kneading machine is reduced to 180 DEG C, open the cooling water delivery valve of the powerful cooling machine to automatically control the cooling water, and send the paste to the green anode forming machine for molding production; the green anode forming machine does not have a vacuum pumping system; D. Real-time detection of the bulk density and appearance of the green anode blocks produced in step C, when the bulk density and appearance are qualified, reduce the pitch feeding amount, so that the ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time returns to the normal production ratio. Example 2

[0018] The method for quickly starting production after the shutdown of the green anode forming system uses a non-vacuum green anode forming machine, and includes the following steps: A. Before production, the following operations are performed: A01. The liquid pitch delivery pump and the batching pump are heated to 220 DEG C, the preheating screw heat medium oil inlet and outlet valves are opened, the preheating screw heat medium oil outlet temperature is heated to 260 DEG C, and the mold steam total valve of the forming machine is opened to heat the forming machine mold to 110 DEG C; A02. Start the liquid pitch delivery pump to pump the pitch from the pitch storage tank into the high tank, and start the pitch batching pump to return the liquid pitch to the pitch storage tank through the pitch flowmeter pipeline, realize pitch self-circulation, so that the high tank pitch liquid level is above 1.55 meters, and the pitch temperature is 190 DEG C; B. Start the forming system for production, and the process of starting the forming system for production includes the following steps: a. Start the cooling circulating water system; b. Start the pitch flue dust collection system; c. Start the batching, kneading and conveying system; d. Start the forming machine system and enter the automatic operation mode.

[0019] The parameter setting includes the following steps: B01. Set the ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time to 1:0.19; B02. The cooling water delivery valve of the powerful cooling machine is in the closed state; B03. Adjust the current of the kneading machine so that the peak current is between 190-200 A; C. Production of blocks: first use emulsified oil to spray lubricate the green anode forming machine, then continuously discharge the high-temperature unqualified paste in the kneading machine until the paste temperature in the kneading machine is reduced to 190 DEG C, open the cooling water delivery valve of the powerful cooling machine to automatically control the cooling water, and send the paste to the green anode forming machine for molding production; the green anode forming machine does not have a vacuum pumping system; D, real-time detection of the bulk density and appearance of the green anode block produced in step C, and when the bulk density and appearance are qualified, the pitch feeding amount is reduced to restore the normal production ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time. Example 3

[0020] The method for quickly starting production after the shutdown of the green anode forming system uses a non-vacuum type green anode forming machine, and includes the following steps: A, before production, the following operations are performed: A01, the liquid pitch delivery pump and the batching pump are warmed up to 210℃, the preheating screw heat medium oil inlet and outlet valves are opened, the preheating screw heat medium oil outlet temperature is warmed up to 250℃, and the forming machine mold steam total valve is opened to warm up the forming machine mold to 105℃; A02, the liquid pitch delivery pump is started to pump the pitch from the pitch storage tank into the high tank, and the pitch batching pump is started to return the liquid pitch to the pitch storage tank through the pitch flowmeter pipeline to achieve pitch self-circulation, so that the pitch liquid level in the high tank is above 1.55 meters and the pitch temperature is 180℃; B, starting the forming system for production, which includes the following steps: a, starting the cooling circulating water system; b, starting the pitch fume dust collection system; c, starting the batching, mixing and conveying system; d, starting the forming machine system and entering the automatic operation mode.

[0021] The parameter setting includes the following steps: B01, setting the ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time, so that the pitch feeding amount per unit time is 3-8% higher than that in normal production, and in this embodiment, the ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time is set to 1:0.17; B02, the cooling water delivery valve of the forced cooling machine is in the closed state; B03, adjusting the current of the mixer to a peak current of 185-195A; C, producing the block: first spraying emulsified oil to lubricate the green anode forming machine, then continuously removing the high-temperature unqualified paste in the mixer until the paste temperature in the mixer is reduced to 185℃, opening the cooling water delivery valve of the forced cooling machine, and automatically controlling the cooling water to send the paste to the green anode forming machine for forming production; the green anode forming machine does not have a vacuum pumping system; D, real-time detection of the bulk density and appearance of the green anode block produced in step C, and when the bulk density and appearance are qualified, the pitch feeding amount is reduced to restore the normal production ratio of the dry aggregate feeding amount and the pitch feeding amount per unit time. Example 4

[0022] Based on the method in Example 3, production restart after molding shutdown is accelerated, and the time for producing qualified green anodes after startup is reduced, while the waste paste discharge time after molding shutdown is reduced from 1 hour to 25 minutes. Assuming a molding paste feed rate of 22 t / h, two shutdowns and restarts per month, and a paste return processing cost of 350 yuan / t, the annual cost savings are calculated as follows: 2*12*(60-25) / 60*22*350 / 1000=107,800 yuan.

Claims

1. A method for rapid start-up of production after shutdown of a green anode forming system, characterized in that, It comprises the following steps: A. Before production, the following operations are performed: A01. The liquid asphalt delivery pump and the batching pump are heated to 200-220℃; the preheating screw heat medium oil inlet and outlet valves are opened, and the preheating screw heat medium oil outlet temperature is heated to 240-260℃; the mold steam total valve of the forming machine is opened to heat the forming machine mold to 100-110℃; A02. The liquid asphalt delivery pump is started to pump the asphalt from the asphalt storage tank into the high tank, and the asphalt batching pump is started to return the liquid asphalt to the asphalt storage tank through the asphalt flowmeter pipeline, realizing asphalt self-circulation, so that the liquid level of the high tank asphalt is above 1.55 meters, and the asphalt temperature is 170-190℃; B. Start the forming system for production, wherein the parameter setting comprises the following steps: B01. Set the ratio of dry aggregate feeding amount and asphalt feeding amount per unit time, so that the asphalt feeding amount per unit time is 3-8% higher than that in normal production; B02. The cooling water delivery valve of the forced cooling machine is in the closed state; C. Production of blocks: first, spray emulsified oil to lubricate the green anode forming machine, then continuously remove the high-temperature unqualified paste in the kneading machine until the paste temperature in the kneading machine is reduced to 180-190℃, then open the cooling water delivery valve of the forced cooling machine, and automatically control the cooling water to send the paste to the green anode forming machine for forming production.

2. The method according to claim 1, wherein the step B of starting the forming system for production comprises the following steps: a. Start the cooling circulating water system; b. Start the asphalt flue gas dust collection system; c. Start the batching, kneading and conveying system; d. Start the forming machine system and enter the automatic operation mode. In the step B01, the ratio of dry aggregate feeding amount and asphalt feeding amount per unit time is 1:0.16-0.

19.

3. The green anode forming system shutdown to quick start production method of claim 1 wherein:

4. The method according to claim 1, wherein the step B of parameter setting further comprises the following step: B03. Adjust the current of the kneading machine so that the peak current is between 180-200A.

5. The method according to claim 1, wherein in the step C, before starting the production of blocks, the green anode forming machine is first lubricated by spraying emulsified oil.

6. The method according to claim 1, further comprising the following step: D. Real-time detection of the bulk density and appearance of the green anode blocks produced in step C, and when the bulk density and appearance are qualified, reduce the asphalt feeding amount so that the ratio of dry aggregate feeding amount and asphalt feeding amount per unit time returns to the normal production ratio. The green anode forming machine is a non-vacuum type green anode forming machine. ​ ​ ​ 7. The green anode forming system shutdown to quick start production method of claim 1 wherein: ​