[China Aluminum Industry Network] 1. Describe the method for determining the angle of repose of alumina.
Answer: The method of determining the angle of repose is to allow alumina to fall from a fixed funnel and stack it into a conical shape on a horizontally arranged plate. The angle formed by the plate and the cone is the angle of repose.
2. What is the raw material for aluminum electrolysis? What is flux? What are the fluxes?
Answer: Alumina; fluoride salts; cryolite, aluminum fluoride, calcium fluoride, magnesium fluoride, lithium fluoride (to answer more than four).
3. Does the presence of carbon particles and alumina suspension in the electrolyte increase or decrease the resistivity of the electrolyte?
Answer: Increase.
4. What is the method of cryolite-alumina molten salt commonly used in aluminum electrolytic production?
Answer: Hall-Erofa.
5. Is the electrolyte in the production of modern aluminum electrolysis acidic or alkaline?
Answer: Acid.
6. What are the hazards of the sediment in the electrolytic cell bottom?
Answer: 1 The precipitate at the bottom of the furnace wears away from the cathode carbon block as the liquid flows. 2 The slot resistance is increased, so that the current distribution on the cathode is not uniform.
7. What are the causes of the bottom deposits?
Answer: 1 The technical conditions are the main reasons for control errors; 2 Aluminium in the production operation, extinguish the anode effect, replace the anode, lift the anode busbar, and my company's plugging seams will fall into excess alumina; 3 Poor performance Alumina.
8. What performance should the electrolytic tank side wall have?
Answer: 1 high resistivity, good thermal conductivity; 2 does not react chemically with molten cryolite; 3 does not react with aluminum and sodium 4 porosity is small, does not penetrate the electrolyte and aluminum, is not oxidized by air.
9. What is the function of using aluminum refractories with refractory materials and insulation materials?
Answer: 1 to save heat; 2 to maintain the necessary thermal balance; 3 to extend the life of the tank.
10. What are the three main factors that affect the production of aluminum electrolysis?
Answer: 1 aluminum liquid reflux; 2 aluminum fluid fluctuations; 3 rolling aluminum.
11. Why is the new anode just set into the electrolysis cell not conductive?
Answer: The new anode is just set into the embedded part of the electrolyzer and will immediately produce a condensed electrolyte layer. The electrolyte layer will quickly thicken and provide insulation.
12. What are the three ways of preheating the electrolytic cell?
Answer: 1 carbon particle preheating method; 2 aluminum liquid preheating method; 3 fuel preheating method.
13. What are the two ways to start the electrolytic cell?
Answer: 1 dry start; 2 regular start.
14, electrolytic cell technical parameters include those?
Answer: current intensity; cell voltage: polar distance; temperature; electrolyte composition; electrolyte and aluminum liquid level and anode effect.
15. What is the polar distance of the electrolytic cell? How much does the pole pitch of an industrial cell generally remain?
Answer: The distance from the bottom of the anode to the aluminum Mirror; 4~5cm.
16, the electrolytic temperature is generally composed of which two temperatures?
Answer: It consists of the primary crystal temperature and superheat of the electrolyte.
17. There are several alumina feed points in our electrolytic cell, and several aluminum fluoride feed points?
Answer: 4 alumina feed points, 2 alumina feed points.
18. What is the normal control range of the alumina concentration in our electrolytic cell?
Answer: 1.5%~2.5%.
19. What is the anode effect coefficient?
Answer: The number of anode effects assigned to each cell per day is called the anode effect coefficient.
20. Please describe the "two-circle law" that extinguishes the effect.
Answer: When the effect occurs, quickly rush to the side of the electrolysis cell where the effect occurs. Prepare the effector, uncover the furnace cover, quickly observe the effect voltage at the slot control machine, and then return to the aluminum outlet to observe the shelling and blanking. In case that the electrolyzer performs the effect extinguishing effect after the effect processing is completed automatically, this is the “front circleâ€; after the effect is extinguished, the carbon residue is salvaged, and after the furnace cover is covered, the cooling hole on the side of the electrolytic cell and the cathode steel rod are checked The controller observes the tank voltage. The voltage below 4.0v is to be immediately lifted to the set voltage value, and then the cooling hole and the cathode steel rod are returned to the large surface from the other side of the tank. This is “second lapâ€.
21. What are the methods to increase the output of a series of electrolytic cells?
Answer: 1 increase the current intensity; 2 increase the total number of tanks day and night; 3 improve current efficiency.
22. What are the common diseases?
Answer: 1 cold trough; 2 hot trough; 3 electrolyte containing carbon and carbonized aluminum; 4 anode long package; 5 rolled aluminum; 6 anode fall off.
23. What is the harm of the electrolytic bag anode bag?
Answer: 1 increase the electrolyte temperature; 2 reduce the current efficiency; 3 increase energy consumption.
24. What are the causes of the long anode package?
Answer: Generally, carbon slag is deposited on a certain part of the bottom of the anode, or there is a large number of large-resistance electrolyte blocks at the local corresponding cathode, which prevents the normal passage of the current and causes the anode to be locally difficult to consume. Form a mass.
25. What are the factors that affect the reduction of current efficiency in industrial electrolyzers?
Answer: (1) Aluminum is a solution and reoxidation reaction: Aluminum is oxidized by the anode gas, causing loss of aluminum. (2) Other factors. 1 The re-oxidation of sodium and sodium generated by electrolysis causes current loss; 2 generates carbonized aluminum; 3 generates metal fog; 4 electronically conductive; 5 impurities in electrolyte discharges power consumption (3 correct answers).
26. What are the four consecutive steps in the dissolution loss of aluminium in industrial aluminum reduction cells?
Answer: 1 A dissolution reaction occurs at the metal-electrolyte interface; 2 The reaction product diffuses out of the interfacial layer; 3 The reaction product enters the electrolyte as a whole; 4 The reaction product is oxidized by the anode gas carbon dioxide and carbon monoxide.
27. What are the methods for determining the current efficiency of aluminum electrolytic cells?
Answer: inventory method, regression method, gas analysis method.
28. What transportation technology is used to transport materials for large prebaked cells above 160KA in China?
Answer: Dilute phase, dense phase, ultra-dense phase
29. In the electrolytic production, how much is the theoretical consumption of alumina consumed to produce 1 ton of primary aluminum?
Answer: 1889kg.
30. What tools should be prepared before implementing AC operations?
Answer: Iron hooks, carbon slag scoops, brooms, shovels, measuring rods, alumina crucibles, furnace crucibles, furnace filters, etc. (Answers of 6 or more).
31, the anode will be too high or too low will cause what harm?
Answer: If the anode is set too high, the anode conducts electricity poorly. If the anode is set too low, the anode will be subjected to excessive current and flow will be biased. This will cause the vibration of the electrolytic cell.
32. When changing poles, after checking the anodes, what items should be checked?
Answer: Whether there is crust, carbon residue, neighboring situation, furnace bottom situation, two levels and so on.
33. What is the purpose of adding aluminum oxide?
Answer: Insulation, prevent anode aging, reduce pressure drop between steel jaws and carbon block.
34. There are materials in the bins. What are the reasons for the discharge of the electrolytic cells?
Answer: The solenoid valve is broken, the blanking valve is closed, the air-moving chute is blocked, and the feeding cylinder fails.
35, electrolyzer groove control machine has what function?
Answer: The slot control box has normal control, AE processing, AC processing, voltage adjustment, hoist power supply, 1DL, drive solenoid valve, effect lamp, manual single action, lift anode and other control functions, on-line working status.
36. When electrolyzers are relatively empty, what are the general phenomena?
Answer: Subsidence of the shell surface, many fire eyes, high electrolyte levels, high furnace temperature, voltage pendulum, and severe heat dissipation.
37. Under what circumstances do you stop measuring the current distribution?
Answer: The anode current distribution operation should be terminated when abnormal voltage to ground, voltage drop, aluminum output, AC operation, bus lift, AE, and abnormal current.
38. What should be done when the anode falls off during roasting?
Answer: Do not replace the anode. Only lift the guide rod out.
39. How many days is the period of our company's 300KA series of bus lifting?
Answer: 18 days.
40. What are the more easily volatile additives in electrolytic production?
Answer: Aluminum fluoride.
41. When more than two AEs occur in a trough in a class, what should you do?
State, whether the shelling and feeding cylinder is normal, whether the shelling and feeding solenoid valve is normal, whether there is any material blocking or card strike.
42. What is the electrolyte weight ratio (CR value)?
Answer: Refers to the weight ratio of NaF to ALF3 in the electrolyte.
43. Briefly describe the anode exchange operation sequence?
Answer: When AC is not set accurately or the cartridge is not tightened, bias current or insufficient current will reduce the current efficiency. Insulation will not increase or the blocking material will cause the slider to destroy the heat balance of the electrolytic cell. The crusts were not clean. It will cause the bottom of the furnace to precipitate or crust, or the anode bag; if not, the shape of the furnace will be destroyed.
44. What should be done after the blanking point is blocked by alumina?
Answer: (1) Open the alumina at the feed point. (2) Check whether the shelling system is normal. (3) manually hit the shell solenoid valve to break through the blank point. (4) Alumina can be used as insulation material or plugging seams.
45, anode guide rod aluminum - aluminum pressure drop range is how much? What are the main reasons for excessive pressure drop? How to reduce the aluminum-aluminum pressure drop?
Answer: The aluminum-aluminum pressure drop is less than 10mV; the main causes are: (1) The pressure contact surface of the anode guide rod and the busbar is not even. (2) The clamp is not tightened. (3) The anode is not positively installed, and the pressure contact surface becomes smaller. (4) There is dust or oil on the pressure contact surface; (1) Use a hammer to knock down the guide rod and the bus bar. (2) After replacing the anode, tighten the clamps. (3) The opening must be well opened, and the material in the seam should be destroyed. (4) Grind the anode guide with a grinder.
46, how much is the electrochemical equivalent of aluminum? How to understand?
Answer: The electrochemical equivalent of aluminum is 0.3356g/Ah; the meaning is that the amount of aluminum deposited when passing through the electrolytic cell 1Ah is 0.3356g
47. Where did the original aluminum quality iron and silicon come from? How to avoid excessive iron in aluminum water?
Answer: The iron in primary aluminum mainly comes from cathode steel rods and anode steel claws, and a small part comes from alumina and iron tools; measures to avoid iron in aluminum water (1) Carefully maintain the electrolytic cell and do not cause damage to the electrolytic cell. (2) Prevent anodization. (3) Prevent the anode from falling off. (4) Prevent the electrolyte from being too high.
48, what is the main purpose of aluminum?
Answer: Transportation, Construction, Packaging, Electrician
49. What is the double balance of the electrolyzer?
Answer: Double balance refers to material balance and energy balance.
50. Under normal circumstances, what is the relationship between the solubility of alumina and temperature?
Answer: The solubility of alumina increases with temperature.
51, the alumina concentration is too high will cause the consequences of electrolytic tank?
Answer: (1) The bottom of the furnace is precipitated. (2) Overheating is too high. (3) The temperature of the electrolysis rises too fast. (4) The electrolyte is sticky.
(5) The bottom pressure drop increases.
52, what is the role of coke?
Answer: (1) Connect the cathode and the anode so that the electrolytic cell forms a pathway. (2) Level the bottom of the furnace to evenly distribute the current. (3) Generate heat and melt cryolite.
53. What are the benefits of slotted anodes in electrolytic production?
Answer: 1 Wetting of the electrolyte and anode is good. 2 Full-current operation can be achieved in a short period of time. 3 is conducive to the discharge of anode gas, reducing the agitation of molten aluminum bubbles.
54, if the residual height is 15cm, the anode consumption rate is 1.5cm/day, the anode exchange cycle is 30 days. Q: How high is the height of the new anode in the tank?
Answer: 600cm.
55, in the process of changing the anode, in order to ensure the uniformity of the current of the anode carbon block in the new and different degrees of the tank, take the cross-polarization method. The basic principle is?
Answer: (1) Change the replacement time of adjacent anode carbon block groups and try to ensure the current distribution is even as much as possible. (2) Maintain the same number of newly replaced carbon block groups on both sides of the bus beam to ensure the beam The weight on both sides is equal.
56. How much electricity should I use to produce a ton of aluminum?
Answer: degrees (DC).
57. What does “four lows and one high†often mean in electrolytic production?
Answer: Four low: (1) low temperature (2) low alumina concentration (3) low molecular ratio (4) low effect factor
One high: high pitch
58, what is the decomposition voltage?
Answer: This refers to the small voltage required for this component to electrolyze for a long time and precipitate the electrolysis product.
59. The utilization rate of energy in electrolytic aluminum production is about?
Answer: 45%-50%
60, what are the ways to reduce electricity consumption?
Answer: (1) Reduce the average voltage (2) Improve the current efficiency
61, what factors affect the electrolyte wetting?
Answer: (1) Electrolytic temperature (2) Alumina concentration (3) Molecular ratio (4) Anode material (5) Additive
62, anode overvoltage include?
Answer: Reaction overvoltage + film resistance voltage + concentration overvoltage + barrier overvoltage.
63, cathode overvoltage include?
Answer: Concentration overvoltage + barrier overvoltage.
64, what are the doctrines of the anode effect mechanism?
Answer: (1) Hydration theory (2) fluoride ion discharge theory (3) Electrostatic mechanics theory (4) The theory of anode to electrolyte rejection.
65, what are the advantages of low-temperature electrolysis?
Answer: (1) High current efficiency. (2) High energy utilization. (3) Good operating environment. (4) Long service life
66, what are the disadvantages of high temperature electrolysis?
Answer: (1) low current efficiency, (2) low energy utilization, (3) poor operating environment, and (4) short tank life
67, what is the temperature range of low temperature electrolysis?
Answer: 800-900 degrees Celsius.
68. What is an inert anode?
Answer: This refers to those anodes that are not consumed or consumed in trace amounts in the current cryolite-alumina molten salt electrolysis.
69, electrolytic tank sidewall material should have what characteristics?
Answer: (1) At the top and back of the side wall, there is a great anti-oxidation capability for air at a high temperature of 500-600°C. (2) It has good corrosion resistance to high temperature 950-970°C cryolite melt and aluminum liquid. (3) Poor wetting of aluminum. (4) Has good thermal conductivity and mechanical strength. (5) has a good resistivity.
70, what is the basis for computer control of alumina concentration?
Answer: A U-shaped graph of changes in voltage as a function of alumina concentration.
71. What are the causes of the abnormalities in the broadcast of live broadcasts?
Answer: (1) Blocking material. (2) less material. (3) "Black material". (4) Empty bin. (5) hit the shell long bag.
72, under what circumstances abnormal voltage appears?
Answer: The operating voltage is 400mv above the set voltage or 300mv below the set voltage.
73, what kind of point-feeding adaptive control?
Answer: The controller of the control system automatically adapts to changes in the process conditions or adjusts the control parameters to a constant value, regardless of the process itself.
74. What are the gases that pollute the environment in the smoke generated during the electrolysis process?
Answer: (1) The vapor of the molten electrolyte. (2) HF gas generated due to the hydrolysis of the electrolyte. (3) Sulfur dioxide gas generated by anodization. (4) Drops of electrolyte with the anode blister. (5) Raw material dust generated during feeding.
75. Does the company adopt dry or wet method to purify electrolytic gas?
Answer: Dry method
76, hot trough what characteristics?
Answer: (1) The flames are yellow and weak. (2) Cinder is not clearly separated in the electrolyte. (3) The electrolyte is yellow and shiny. (4) The residual pole is white and smokes when it is lifted from the tank. (5) The electrolyte circulation is severe. (6) Furnace and leg extensions dissolve, and the electrolyte level is high. (7) The liquid surface of the iron pad inserted in the electrolyte is not clear after removal. (8) The effect voltage is low.
77, what is the reason for the hot trough?
Answer: (1) The process conditions and operating system are not suitable. (2) The level of aluminum is too low. (3) The pole pitch is too low or too high. (4) The furnace is not regular and the current is concentrated towards the side. (5) There are many deposits at the bottom of the furnace, and there is a large agglomerate at the bottom and the bottom pressure drop increases. (6) The effect is too long.
78, how to confirm the anode long package?
Answer: (1) Measure the anode pressure drop (2) Check whether the anode steel jaws are red. (3) Compare the temperature around the anode and whether it is locally hot. (4) Observe the color of the flame around the anode.
79, how to deal with anode long packet slot?
Answer: (1) Found a group of anode long bags, first put this group of anodes, observe the severity, knock out the protruding part, and replace the anode. (2) If it is a small round package, it is not serious and it can be treated by raising the group of anodes. (3) For long packages, raise the operating voltage until the voltage does not swing. (4) Cylinder and lump should be salvaged when the anode is replaced.
80. What is the reason for the aluminum rolling?
Answer: (1) The bottom of the furnace is not flat, and there are many sediments and large crusts. (2) The legs stretched too hard around the hearth. (3) Pressure tank. (4) The furnace is not regular. (5) The anode and cathode currents are unevenly distributed.
81, how to deal with rolling aluminum tank?
Answer: (1) Found that local aluminum rolling, first check the current distribution and polar distance. (2) Inspect the furnace and place it in a block where it is empty. (3) If full-grooved aluminum is found, first raise the voltage, check the current distribution, and fill the aluminum in the tank with a low aluminum bath.
Eramic Knife Set,Knife Sets,Boning Knife Set,Bread Knife Set
YANGJIANG TRI-WIN INDUSTRY & TRADE CO.,LTD , https://www.triwintableware.com