Late Yuan Dynasty: I am the true emperor

Chapter 565 There's rice to cook!
In the Yunxiang Hall of the Jiankang Imperial Palace, where Lu Jin usually works, Tao Guangyi led several students who had been sent to prospect for minerals last year, along with about ten top-performing students from the science class, a total of eighteen people, to Lu Jin to report on their work and hear about future work arrangements.

The students, led by Mao Xin, who were prospecting for minerals, had just changed into clean clothes, but their fatigue was still evident. Each of them carried a tray containing mineral samples they had collected from various places, as well as their test reports.

Seeing this, Lu Jin immediately asked, "Why do you look so tired? When you went to search for minerals, did the local officials not cooperate well? Or were they not taken good care of you?"

Mao Xin, who was in the lead, immediately replied, "Your Majesty, please allow me to explain. I went to Hunan. First, I went to Xiangtan, and then to Xinhua County in Shaoyang Prefecture. The local magistrate took good care of us when he learned that we were sent by Your Majesty to search for minerals."

"They not only provided us with food, clothing and lodging, but also found us local guides and even sent more than a dozen guards to accompany and protect us. The students were not mistreated. It's just that we were running around all day, eating and sleeping in the deep mountains and forests, so it was inevitable that we would be a little tired."

"But the student is still young, he just needs to get some rest for a few days after coming back."

Lu Jin nodded. "You've all worked hard for the past six months. Now, give your reports first. After today's meeting, you can all go back and rest. I'll give each of you three days off."

"Thank you, Your Majesty!" the group of youths immediately bowed and expressed their gratitude.

Lu Jin waved his hand. "Let's start with Mao Xin. How's your exploration of manganese and antimony deposits in Hunan going?"

Mao Xin immediately placed his tray on the imperial table in front of Lu Jin before introducing the items.

"Your Majesty, I have indeed found these two minerals in the approximate area you mentioned. This manganese ore sample was taken from Fairy Mountain in Heling Town, Xiangtan County. I have conducted a general survey there. The manganese reserves there are very large, but I am not sure how much exactly. However, it should be able to be mined for a long time."

As he spoke, he opened two bamboo tubes and a paper-wrapped metal ingot, pouring them all onto the paper to show them off. "And this, these are samples of manganese dioxide and manganese tetroxide obtained by directly calcining ore, and this pure manganese ingot refined using the high-temperature reduction method with coke."

“The mining conditions there are also very suitable. Xiangtan is located at the junction of Lianshui and Xiangshui. If the imperial court needs it, it can mine in Xiangtan and transport the ore directly across the Xiangshui River to Dongting Lake and then to the Yangtze River, and then from the Yangtze River to Jiankang. Alternatively, it can set up a smelting plant in the area to directly produce manganese intermediate oxides or manganese ingots, and then transport them to downstream factories.”

"Furthermore, this is the test report. The flame test of this metal is yellow-green, and the oxide obtained after calcination has a significant catalytic effect on the decomposition of hydrogen peroxide. The gas produced is also pure oxygen, so it is undoubtedly manganese ore."

Lu Jin picked up the manganese ingot and weighed it in his hand. The heavy weight made him very satisfied. Among the metal minerals he was looking for, manganese ore was indeed one of the easier to refine because it did not require any 'high-tech' smelting techniques. It only required calcining the ore into oxides beforehand, which could then be reduced at high temperatures with coke. This meant that it could be smelted using ordinary iron smelting furnaces, which was not beyond the technological level of the late Yuan and early Ming dynasties, making mining and smelting more convenient.

Moreover, if you really want to refine manganese steel, you don't actually need pure manganese ingots. You only need calcined manganese dioxide as raw material, which can be thrown directly into molten iron. The oxygen atoms in it will automatically combine with the carbon in the molten iron. This process not only decarburizes the molten iron into steel, but also incorporates manganese. As long as the proportion is right and the testing and metallographic analysis technology is up to par, qualified manganese steel can be refined using rudimentary methods.

In ancient times, manganese steel was a formidable weapon. It could be used to make cutting tools for various machine tools, which were far superior to high-carbon steel tools and could truly cut through iron like mud.

Secondly, it can also be used to make armor. Manganese steel lamellar armor is much harder than ordinary iron armor and cold-forged steel armor. Even if it only meets the same protection standard, manganese steel armor can be made lighter.

The original two-millimeter-thick armor plates can be reduced to only one millimeter thick with manganese steel armor to achieve the same protective capability. The original 40-pound armor can be reduced to 20 pounds, reducing the burden on soldiers and increasing their mobility. This alone is nothing short of a cheat code.

In addition, manganese steel can also be used to make heavy-duty rails. Its toughness and wear resistance are much stronger than ordinary wrought iron rails and carbon steel rails. Therefore, finding manganese mines is one of the prerequisites for Lu Jin to develop railways.

However, this is only powerful; for other things that are difficult to refine, you need to use more sophisticated methods to use them.
Lu Jin looked at the test report again and immediately praised, "Well done! You even surveyed the terrain and came up with mining and transportation plans. I'll give you a big commendation this time. What about the other antimony mine?"

Mao Xin immediately replied, "Your Majesty, the antimony mine was found by an old tin miner from Xinhua County, Shaoyang Prefecture. Finding this antimony mine wasn't difficult at all."

"Oh? What exactly is the situation?" Lu Jin immediately became interested upon hearing this.

Mao Xin immediately explained, “Xinhua County originally had a large tin mine, which is said to have been mined since the Song Dynasty. There were a large number of skilled miners and craftsmen who smelted tin and made tinware there.”

"After I arrived there, I asked the guide, who then took me to an old miner. The miner said that he knew of a type of ore dozens of miles away that could be smelted into metal, but it was neither tin, nor silver, nor lead. He didn't know what it was either. When he heard that I was looking for antimony ore, he took me to see it. After testing, I learned that it was indeed the antimony metal that His Majesty was looking for."

"This antimony mine is an antimony sulfide deposit, located eighty miles away from the tin mine in Xinhua County. What's even more bizarre is that the local miners have already figured out how to smelt antimony on their own. Therefore, if Your Majesty needs to mine it, you can simply set up a factory there and let the local miners mine and smelt it themselves, then supply the court with finished antimony ingots."

"Oh? They can even refine antimony themselves. What method do they use?" Lu Jin became even more curious.

"His Majesty's method is to roast antimony ore to obtain antimony trioxide gas, then collect antimony oxide powder using a condensation method, and finally smelt the antimony oxide powder together with coal powder and soda ash in a furnace at high temperature to produce crude antimony. The finished product is crude antimony with a content of 90% to 95%."

"But local craftsmen also have a method. They roast the antimony sulfide ore in a clay crucible at a lower furnace temperature. After roasting, they cool it to extract crude antimony with a high content, which is then melted and cast into ingots."

"However, the students also tried their method and found that only a small amount of rich ore with a particularly high antimony content could be smelted using the crucible method. Most ordinary antimony ore still needs to be smelted using the high-temperature reduction method that His Majesty mentioned."

Lu Jin was stunned. He really didn't know that antimony ore could be refined into crude antimony using the crucible method, and he didn't know how these ancient people came up with this idea.

However, what Lu Jin didn't know was that the antimony mine in Xinhua, Hunan, was actually discovered by people from the Ming Dynasty, probably during the Zhengde period of Zhu Houzhao. It was even recorded in the county annals, which is how it came to be known by later generations. It wasn't until the late Qing Dynasty, at the end of the 19th century, that foreigners were consulted to test the ore samples and it was confirmed that it was an antimony mine.

Moreover, this is the date recorded in the county annals. Before the officials recorded it, did no one discover the antimony mine there? That's clearly impossible. Tin mining in Xinhua has been going on for a long time, and the antimony mine isn't far from the tin mine. Someone must have discovered it long ago; it's just that in ancient times, no one knew what it was, or perhaps they hadn't named the metal. However, this time was different. Mao Xin was carrying an imperial decree, with the specific purpose of finding antimony in the area. After inquiring with local miners and craftsmen, he learned that someone had indeed noticed the mineral long ago, and he found his target effortlessly.

Lu Jin sighed and said, "You're really lucky. You've saved yourself at least a few months."

“That’s true.” Mao Xin nodded, then asked, “Your Majesty, will this antimony mine also be mined on a large scale?”

"No, it's not necessary. We mine manganese ore to smelt manganese steel and make chemical catalysts. Many weapons, armor, and mechanical knives all require manganese steel. However, the demand for antimony is not that great. It's just used to add a little bit to lead-tin alloys as a seasoning to enhance the alloy's hardness and wear resistance."

"For example, when printing books with lead plates, ordinary lead plates can only print a maximum of 100,000 copies before the text becomes blurry. However, by adding antimony, the hardness and wear resistance of the lead plate can be enhanced, and a single lead plate can be printed more than 500,000 times, which can greatly save printing costs and reduce the price of books."

"As for other uses, at most a little more can be added to the lead bullets of the musket to increase the hardness and wear resistance of the lead bullets, but there is no need for it at all. Firstly, antimony is very expensive and we cannot afford to consume it like that. Secondly, we have better steel core bullets, so there is no need to use antimony to increase that little bit of hardness. Moreover, even if antimony is added to the lead bullets, it will not improve the armor-piercing performance much."

"So, as you said, we'll recruit local craftsmen to build a small workshop there. We'll refine about 10,000 to 20,000 jin in small batches, which should be enough for the time being."

"I see, I understand now," Mao Xin said, suddenly realizing.

"Okay, you can sit down and rest for a bit. Hey you, Ji Zhili, can you tell me about the situation in Jiangxi?"

"Yes." Ji Zhili was called on and quickly brought the food over.

“Your Majesty, these are all tungsten ore samples from Jiangxi Province. They contain both wolframite and scheelite, and are divided into different types of deposits. They were mined from Jiujiang Prefecture, Anfu County of Ji'an Prefecture, Xihua Mountain in Ganzhou, and Zhuxi Town in Fuliang County. After testing, I have confirmed that these are undoubtedly tungsten ore. There are also these metallic tungsten powders that were first leached with sulfuric acid to precipitate the ore and then reduced with hydrogen.”

Looking at the various specimens and samples on the tray, the heavy metal tungsten, and Ji Zhili's chemical analysis report, Lu Jin was very satisfied and then asked again.

“You did a good job too. Since there are tungsten mines in these places, which one do you think the imperial court should mine? We don’t need much tungsten for now, so we don’t need large-scale mining, so we can be more flexible in our ore selection methods.”

Ji Zhili thought for a moment before saying, "If that's the case, then I would not recommend the tungsten mine in Fuliang County. Although the tungsten reserves there are large, it is a granite deposit. I have personally tried it there. When I smashed the ore with a pickaxe, sparks flew everywhere. The granite there is too hard. It would be very difficult to mine it."

Lu Jin nodded in affirmation and said, "Your consideration is very correct. So, which mine would you recommend?"

"In terms of convenient transportation, Jiujiang is of course the most suitable, but the composition of tungsten ore in Jiujiang is too mixed, with various calcium tungstate, tungsten sulfide and tungsten oxide mixed together, which is difficult for people who have not studied it to distinguish."

"Secondly, there are tungsten mines in Anfu County, Ji'an Prefecture. They are mainly composed of scheelite, which is calcium tungstate and is suitable for refining metallic tungsten. It is also close to the Gan River, so it is one of the options."

"Finally, there is the black tungsten mine in Xihua Mountain, Ganzhou. The tungsten mine there is mainly composed of quartz veins with tungsten trioxide as the main component. In terms of mining difficulty, it is the easiest one. It can be knocked down with a light tap of a pickaxe. However, there are many mountains there, and the transportation is very inconvenient."

"As for the final choice, the students think it should depend on our specific application, whether we need calcium tungstate or tungsten trioxide. If we choose the right target, we can save a lot of effort in the subsequent processing."

"Your analysis makes a lot of sense. As for which location to mine, I need to think about it some more. Thank you for your hard work. You should rest for now."

"Yes, thank you, Your Majesty."

Looking at the various tungsten ore samples on the tray in front of him, Lu Jin frowned slightly. His purpose in looking for tungsten ore was definitely not to make machine guns, at least not now. Tungsten alloy machine tools and cutting tools required vacuum furnaces, which he couldn't handle at the moment. So the easiest thing to achieve right now was tungsten filament light bulbs.

The Ming Dynasty now possesses the technology to blow glassware. By adding a tungsten filament to a glass bulb and encapsulating it, an incandescent light bulb can be made. Of course, lighting is not the most important thing at the moment. The key point is that the light bulb is the precursor technology to the vacuum tube. With the light bulb, we can continue to develop the vacuum tube, and with the vacuum tube, we can create a practical wireless telegraph machine!
With wireless telegraph machines, the Ming Dynasty could effectively govern its overseas territories. Otherwise, unless Lu Jin could develop transoceanic submarine cables and transoceanic wired telegraphs, but considering the difficulty of that, it seems that wireless stations are more promising.

Although Lu Jin's initial plan is to develop limited telegraph first, the tungsten filament bulb, a precursor technology for radio, can be developed first to pave the way for future radio station development.

If the goal is to make tungsten filament light bulbs, then calcium tungstate would definitely be the preferred mining target. Even sulfuric acid leaching would be unnecessary; tungsten metal could be produced directly by reducing it with hydrogen.

Having figured out the key point, Lu Jin then looked at the last student who was looking for minerals, "Liu Fang, what about you? Did you find any molybdenum mines in Wenzhou?"

18-year-old Liu Fang immediately stepped forward with a tray, “Thanks to Your Majesty’s great fortune, I have finally lived up to your expectations and found this molybdenum mine. The main mine is located in the middle and lower reaches of Nanxi River in Wenzhou. I used the calcination method to produce molybdenum trioxide, and then used hydrogen to reduce it to obtain metallic molybdenum and hydrogen peroxide. After testing, it is indeed a molybdenum mine without a doubt.”

"Moreover, the area is close to a river, so mining can be carried out on-site, and the waste can be transported by water to the East China Sea first, and then transported back to the capital via the Yangtze River."

Upon hearing this, Lu Jin exclaimed with delight, "Now we finally have rice to cook!"

(End of this chapter)