Chapter 944 I am familiar with this matter
In fact, even in Gao Zhendong's previous life, after the technology was improved, the energy consumption of electrolytic aluminum accounted for more than 40% of the production cost, which was considered a large energy consumer. It is even more exaggerated in this day and age.

Seeing Gao Zhendong nodding as he listened, the chief engineer smiled and said, "We all know that you, Chief Engineer Gao, are a master in metallurgy and have a lot of experience in energy conservation and consumption reduction..."

This is not a compliment. Qianyang Steel Plant is located in the city. As an enterprise of the 17th Ministry of Machine Building, Qianshan Aluminum Plant is very clear about the effect of their promotion and use of Gao's blast furnace operating line.

"So we thought, can we ask Chief Engineer Gao to communicate with the ministry and ask the ministry to do some work on energy conservation and consumption reduction in our aluminum plant. Of course, we know that this matter cannot be rushed, but we just want to see if we can get this thing started."

Well, if this was an aluminum plant decades later, I really wouldn’t dare to say anything about this, but as for the aluminum plant now... Gao Zhendong has something to say.

I am familiar with this matter!
He didn't need to look for anything, just the things he remembered seeing at his elders' house were enough for him to use now, after all, those things were related to the aluminum factory. At that time, he had nothing to do at his elders' house, so he spent all his time looking at these things after studying. Gao Zhendong had a very good memory, and he could remember a lot of things casually.

Aluminum is a good thing. One thing is enough to illustrate its importance: making airplanes!
Gao Zhendong may not know anything else, but this one thing is important enough.

"Well, indeed. I have just looked at your current production process, and there is indeed room for improvement in energy consumption." Gao Zhendong smiled. Some improvements may not be possible now, but some are still possible.

Hmm? You understand this too?

This was something the comrades at the aluminum plant had never expected. Their original idea was to get Gao Zhendong to get the department to pay more attention to this matter and get it started.

Steelmaking and aluminum production are two completely different things. It is normal that Chief Engineer Gao does not understand them. I have never heard that he has made any achievements in this area.

"Oh, it would be great if Mr. Gao could give us some guidance now! Come on, everyone, listen."

Comrades from the aluminum plant's technical department were also in the conference room to receive Chief Engineer Gao. It would have been inappropriate if there were no technical personnel present.

"Let's not talk about electricity for now. I've just heard about the anodes and cathodes you are using. The anode consumption should be more than 500kg/ton of aluminum, right? And from the perspective of material properties, the mechanical, electrical and thermal conductivity of the cathode are not very good." As soon as Gao Zhendong went into the details, his entry point was different from what his comrades thought.

If we talk about electrical matters, he is an electrical engineer and has also worked on processes such as ESR, so it is not surprising that he has some understanding of it. However, the anode and cathode of electrolysis are another matter.

"Yes, yes, yes. Sometimes the anode consumption even exceeds this number. As for the cathode, the cell life is indeed not ideal. The aspects you mentioned just now are not good either." The comrades at the aluminum plant were not surprised that Gao Zhendong could see these things, as they were all written on paper.

However, they didn't quite understand how Chief Engineer Gao could tell that the parameters were not good given the bare data on paper without any comparison.

But they didn't expect that Gao Zhendong could not only see it, but also find a solution.

"As for anodes, the quality of our petroleum coke and asphalt coke is indeed average. I suggest you communicate with the Northeast Carbon Research Institute. They are using asphalt coke and petroleum coke to make graphite blocks, and they have worked with me to improve the graphite production process. I don't know if their process can be used here, but at least for the inherent deficiencies of asphalt coke and petroleum coke, the quality of their final graphitized products is still good. You can coordinate this matter through the ministry."

Gao Zhendong is not sure whether the improved graphite production process he provided to the Northeast Carbon Research Institute is useful, but it is at least a direction. The biggest problem is that a considerable portion of the products of the Northeast Carbon Research Institute are used in places where cost is not a factor. He is not sure whether they can be used in electrolytic aluminum anodes with extremely high consumption.

But at least if the Northeast Carbon Research Institute delegates some of its technology, it will have some effect. The normal consumption of ordinary electrolytic aluminum process is about 400kg/ton of aluminum, so there is still a lot of room for improvement, and it is relatively easy to see results.

"That would be great. We have always suffered from the poor quality of anode carbon blocks and high consumption. If we can improve them a little, we can save a lot of costs."

"As for your cathode, you can consider several aspects. First, the material. You use anthracite lumps, right?"

"Yes, Mr. Gao, you are an expert." The comrade from the technical department of the aluminum plant felt like he had found his own person. The other person could explain it clearly, which showed that Chief Engineer Gao really had research in this area.

"There is a lot of coal in Guizhou, and the abrasion rate of anthracite is lower. It is normal for you to choose this thing according to local conditions."

I admire him. He even found the reason. "Chief Engineer Gao, is there something wrong with this charcoal block?"

Gao Zhendong nodded and shook his head: "For your current conditions, there is no problem with this carbon block. Production is determined by environmental conditions. Blindly pursuing higher is not a good thing. Actual work is often limited. However, if your conditions are good, I suggest using graphitized cathode carbon blocks. In terms of mechanical properties, electrical conductivity, and thermal conductivity, this type of cathode carbon block is better than anthracite. Although the abrasion rate is slightly higher, the overall performance is better."

To some extent, graphitized carbon blocks can be said to be the result of special tuning. Their mechanical properties and electrical and thermal conductivity are definitely better than those of anthracite coal blocks. Otherwise, the Northeast Carbon Research Institute would not exist. After all, graphite is not only used in aerospace.

Gao Zhendong also uses this thing when he pulls silicon single crystals.

"Oh, OK, I understand. Thank you, Mr. Gao." Gao Zhendong did not arbitrarily say that the current smokeless coal blocks cannot be used. In their opinion, this is very pragmatic and fully takes into account the existing conditions. However, the new direction proposed by Gao Zhendong has greatly inspired them. Coal is charcoal, and they did not expect that there are so many twists and turns.

"As for the age of the tank, you can consider using carbon-silicon nitride side wall linings and bottom anti-seepage linings, which should be able to improve the age of the tank. But again, we have to take it step by step according to the conditions."

Gao Zhendong finally talked about what they were most concerned about.

"As for electricity, my first suggestion is to lower your electrolysis voltage. Every 1mV reduction counts."

Completely contrary to most people's first impression, the voltage of electrolytic aluminum is very low. Let's put it this way, theoretically you can touch the switch with your hand, it is less than 4V. Every 1mV reduction can improve the current efficiency, and current efficiency is an important factor affecting power consumption.

"Lower the voltage? Then the current won't be enough?"

This is a contradiction. When the voltage is low, the current is small.

"Lowering the aluminum oxide concentration in the electrolyte can reduce the resistance of the electrolyte, but don't lower it too much. If it is too low, the resistance will go up again, and it will increase the anode effect and reduce the current efficiency. You can experiment with this, and I suggest it be between 3% and 4%." Gao Zhendong said with a smile.

Comrades, I don’t know where Gao Zhendong got this number. Maybe someone has already done some research on it.

In fact, the relationship between the aluminum oxide concentration in electrolytic aluminum and the resistance is very interesting. It decreases all the way from 8% to about 4%, but when the concentration is lower than 4%, the resistance will increase instead.

"Oh, I see. Let's go back and test them one by one."

“In addition to low pressure, the recommendation is low temperature.”

"Low temperature? Wouldn't low temperature reduce the intensity of the electrolysis reaction?"

Gao Zhendong shook his head: "No, the formation of products during electrolysis is theoretically only related to the number of electrons transferred. As for the fact that low temperature can reduce power consumption, the reason is very simple. The higher the reaction temperature you want to maintain, the more heat the electrolytic cell will radiate into the air. I think everyone understands this principle, right?"

"Huh? So simple?"

"That seems to be the case."

"The great way is simple, the great way is simple."

Gao Zhendong added: "I have estimated that for every 10 degrees drop, the current efficiency can be increased by 1% to 2%. This is a very impressive number. Of course, it cannot be too low. In theory, as long as the temperature is 200 degrees Celsius higher than the melting point of aluminum, normal production can be achieved. However, we all know that theory must be combined with practice. In addition, temperature control requires a little superheat to complete the control process. So my suggestion is that you can try to control the electrolysis temperature between 925 degrees Celsius and 935 degrees Celsius. At the same time, strengthen the insulation measures of the electrolytic cell to further reduce power consumption."

Although we don't know how Gao Zhendong got so many data when he doesn't even work on electrolytic aluminum, the comrades don't care about that anymore. If it is really as Chief Engineer Gao said, then a 3% increase in current efficiency is very likely to be achieved, and it doesn't require too much cost.

Don’t underestimate this slight improvement. The theoretical energy consumption of electrolytic aluminum is 6320 kWh/ton, and in reality it is far higher than this number.

"Chief Engineer Gao, is there anything else?"

Gao Zhendong thought for a moment and said with a smile: "Let me summarize it for you: 'low temperature, low molecular weight ratio, low aluminum oxide concentration, low effect coefficient, and high interpolar distance'. Of course, you should pay attention to the problem of "too much is as bad as too little" for each of the "highs and lows" here."

"Four lows and one high. Got it? Let's adjust the process in this direction and see how much electricity we can save."

Gao Zhendong said: "But there is one thing you need to study first, otherwise you won't be able to achieve low temperature."

"Boss Gao, what is that?"

"You need to change the electrolyte system, just like the slag system of ESR electroslag remelting. If you don't handle this thing properly, you can't do this job well."

(End of this chapter)