Lin Xi nodded: "Let's do it first!" ”

The copper master said: "We are making copper sheets in a hurry now, and it is not particularly flat, is there a problem?" ”

Lin Xi said: "Not too flat? ”

The master coppersmith said, "Venerable Master, the most delicate and pure copper we have here is wet copper smelting, which is copper that is exchanged with iron from bile water. ”

[Note: Wet copper smelting, wet copper smelting uses sulfuric acid to convert the copper element in the copper ore into soluble copper sulfate, and then puts the iron into the copper sulfate solution to replace the copper, this method is called wet copper smelting.

Wet copper smelting technology was invented by ancient people in China, and its principle is to use displacement reaction to produce metals. China is the first country in the world to use wet copper smelting.

In many works of the Han Dynasty, it is recorded that "stone gall can turn iron into copper", and Jin Gehong's "Hug Puzi Inner Chapter: Yellow and White" has a record of "coating iron with Zeng Qing, and iron is as red as copper". During the Northern and Southern Dynasties, it was further realized that not only copper sulfate, but also other soluble copper salts could also undergo displacement reactions with iron. Tao Hongjing of the Northern and Southern Dynasties said: "Chicken feces alum is coated with iron in bitter sprinkling (vinegar), and they are all copper-colored", that is, impure basic copper sulfate or basic copper carbonate is insoluble in water, but soluble in vinegar, and can also be replaced with iron after being dissolved with vinegar. By the end of the Tang Dynasty and the fifth dynasty, the principle of water copper smelting was applied to production.

In the Song Dynasty, it developed and became one of the important methods for mass production of copper.

In Europe, wet copper smelting appeared relatively late, and it is said that in the 50s of the 15th century, people immersed iron sheets in copper sulfate solution, and occasionally saw copper appear on the surface of iron, and they were very surprised. 】

Lin Xi roughly knew about wet copper smelting, and in the scientific experiments of later generations of students, this experiment was more favored, the cost was not high, and the effect was obvious, but why the copper master said this, Lin Xi was a little puzzled, so he encouraged: "You say, be concise." ”

The coppersmith nodded:

"Venerable Master, I use copper in the court, because copper itself is money, so it is very valuable.

Natural copper ore is not common, and the smelting effect is not the best. But there is a place where bile-alum water can produce good copper.

If iron is placed in bile alum water (note: copper sulfate pentahydrate, CuSO4·5H2O solution), also known as bile water, copper powder will be deposited. Then it can be collected, that is, the replaced copper powder is collected, and then it is smelted and cast.

I Chao Zhang Qianbo through the technique, once read the "Shennong Book", see the book contains gall alum water can be soaked in iron for copper, Zhang Qian practiced diligently, found out that the 32 springs and 138 ditches of Dexing Xinglichang are rich in bile water, can be immersed in iron to extract copper, in the Song Shaosheng years (note: 1094 ~ 1098) wrote a wet copper smelting monograph - "Copper Immersion Strategy", ordered his son Zhang Jia to dedicate to the imperial court. The imperial court issued a document because of "the use of small expenses and the collection of merit", and the law was placed on Zhulu, "the annual collection of copper millions", was commended by the imperial court.

Since then, Xinzhou Lead Mountain Field, Dexing Xingli Field, Shaozhou (now Shaoguan, Guangdong) Cen Shui Field, Tanzhou (now Changsha, Hunan) Yongxing Field and other mines have fully implemented their wet copper smelting technology and achieved great benefits, especially Shangrao.

The annual output of bile copper can be 100 to 1.7 million catties, accounting for nearly 20% of the total copper output at that time.

Wet copper smelting, after my dynasty Zhang Qian, although the methods used in various places are different, but to sum up, there are three main types. We must be familiar with the great craftsmen who are coppersmiths, and often go to various places to supervise and urge errands, and the situation in each place is more or less different.

The first method is to dig a trench in the vicinity of the bile water producing area with the height of the terrain, lay the bottom with a mat, crush the pig iron, discharge it in the trench, introduce the bile water into the trench and soak, use the color difference between the copper salt solution and the iron salt solution, soak until the color changes, and then put the soaked water, take out the mat, and the copper deposited on the mat can be collected, and then introduce new bile water. As long as the iron is not reacted, it can be produced again and again.

The second method is to set up a bile water tank in the bile water production area, forge the iron into a thin sheet and place it in the trough, immerse the iron sheet with bile water, until the surface of the iron sheet is covered with a layer of red copper powder, take out the iron sheet, scrape the copper powder on the iron sheet, and after scraping off the copper powder, the iron sheet is exposed, and the speed is much faster than having a layer of copper.

The third method is the torment method, in which bile water is introduced into a container made of iron for torment. This method is faster, but it requires fuel and special personnel to operate, and there is more work and less benefit. That's why I use the first two methods for the production of bile copper.

The bile copper powder is delicate, easy to smelt, and the material is particularly uniform.

In fact, Shaoguan is only eight or nine hundred miles away from my cliff mountain, and it turns out that we should have a lot of bile copper.

However, because of the frequent wars, the pseudo-yuan deliberately plundered, and we were originally prepared for war and famine, in addition to silver, we also used copper coins to buy from the people, especially underground transportation, which required a lot of good money, and the copper was used to mint money, and the coarse copper was mostly left, and there were too many impurities, and the Venerable Master cast the artifact, which inevitably required purity and flawlessness, and I am afraid that the Venerable Master's arrangement would be delayed. ”

Song Qing opened his mouth and said: "Copper master, you don't need to be in a hurry, the copper left on this Xuanyi is originally given by the Queen Mother, but it is refined copper, but it is not much, if the Venerable Master wants a hundred catties or a thousand catties, it is not available for the time being, if it is a few catties or dozens of catties, it can be freed up." These are kept for the utensils in the palace. ”

Lin Xi let out a sigh: "What the copper master is worried about, I forgot, these materials we have here are much purer than now, since there is wet copper smelting, you had better take those replaced copper powder." Otherwise, the effect of impurities is very large, and the output power is insufficient. ”

The Coppersmith Says:

"Thank you for your cultivation.

Similarly, there is the problem of lead. ”

Lin Xi asked, "What's wrong with the lead?" ”