The clay mold that was just made couldn’t be directly fired. After it was made, it had to be set aside to dry.

During this process, Han Cheng and Hei Wa worked together to rebuild the furnace with yellow clay mixed with pottery clay. The scale was similar to the previous one.

After completing the furnace, they let it dry for a day and then started a fire inside to accelerate the drying process. The specially made copper-refining ceramic pot was also placed by the fire to speed up the process since drying it naturally would take too long.

Eight days later, both of the newly created items were finally ready.

They placed the ceramic pot on the furnace, connected the two, and the copper-refining project of the Green Sparrow tribe began once again.

Han Cheng climbed the stone steps and stopped when he was level with the furnace’s opening. He tilted the jar he was holding and slowly poured the powdered ore into the pot.

This time, he poured a lot, filling six jars before stopping.

There was no need to worry about the ore powder spilling out from the hole at the bottom because they had already sealed it with a ceramic plate before all this.

After adding the ore powder, the flames began to burn, and the wind roared as it spun around. The intense heat gathered here, passing through the bottom of the ceramic pot and transferring the heat inside, melting the ore powder.

This process was slow, and the ore powder took a long time to begin melting.

As for it fully melting, that would take much longer.

Han Cheng climbed the steps again, leaned back, and glanced at the high-temperature liquid inside the pot.

Hot air rose from it, making it almost unbearable to be near.

"Everyone, get back!" Han Cheng shouted, turning to the people around him.

Hei Wa, who was tending the fire, and the shaman and others gathered to watch all moved away when they heard him.

The people anxiously watched the furnace and Han Cheng, waiting for his next move.

Wearing a leather apron, leather sleeves, and leather gloves on his arms and hands, Han Cheng checked to make sure everyone had moved back. He then gripped the ceramic plate, which was higher than the inside wall of the pot, and pulled it upwards. He moved it aside, and immediately, molten slag began to flow out of the hole.

The extremely hot slag hit the ground with a sizzling sound, sending up white smoke.

Han Cheng didn’t have them collect the slag in ceramic pots.

Instead, he planned to build a sloped area, allowing the slag to accumulate and eventually roll down to the side.

Copper ore contains copper and other metals like gold and silver, which are generally present in trace amounts.

However, Han Cheng didn’t hesitate to discard the slag, treating gold and silver like manure and dirt.

This saying may not be entirely accurate—in Han Cheng’s view, slag containing gold and silver was even less important than manure.

He could afford to be so carefree because, first, he couldn’t separate the gold and silver from the slag.

Second, the value of gold and silver is something humans assign to it. At this point, gold and silver couldn’t serve as equivalents or be traded for food. If he took a large piece of pure gold to exchange for food with another tribe, the tribe would likely refuse the gold, unable to use it, and angrily throw it back at him. ṟåƝО𝖇Εᶊ

The slag didn’t flow smoothly due to the impurities inside and its thick consistency.

It seemed that the furnace still needed further improvements.

The outlet for discharging the materials should be changed from a flat opening to a slanted one, making the flow much smoother.

After quite a while, the slag was finally fully drained.

Han Cheng asked Eldest Senior brother to bring a prepared ceramic pot to place under the outlet where the copper liquid would flow. Then, he removed the ceramic plate that had blocked the hole. The high-temperature metal liquid began to flow slowly out, falling into the ceramic pot below.

As the intense heat gradually dissipated, the copper liquid in the pot cooled and solidified.

The ceramic pot was smashed open to reveal a half-full, pot-shaped purple copper ingot.

Looking at the large copper ingot, Han Cheng, the shaman, eldest senior brother, and others anxiously concerned about this project couldn’t help but smile.

The shaman, a devout old priest, followed his principle of giving all glory to the gods and began to praise the god who had never paid attention to him.

Han Cheng, seeing this, felt rather helpless. All this had been achieved through the hard work of himself and his people—what did the gods do with it?

Though he thought this, Han Cheng didn’t say it aloud. After all, he was still dressed in the glorious robe of the "Divine Child" and was the greatest beneficiary.

After looking at the copper ingot, Han Cheng used a stick to poke through the clumps of slag.

When he turned the slag over with the stick, he discovered there was still quite a bit of solidified purple copper at the bottom.

No wonder the copper ingots from this batch were so good—it seemed that a lot of copper liquid had also been extracted.

It seemed they had added too much ore powder this time; they would need to use less next time.

Han Cheng thought this as he called for Shi Tou and weighed the copper ingots they had just produced.

After weighing, he recorded the amount of ore powder used and the number of copper ingots obtained.

This way, they would have a reference when they did this again.

It was impossible to avoid wasting any copper liquid, but they could certainly reduce the waste compared to this time.

Of course, the ore quality varied, so the copper content and the slag ratio would also differ, meaning it couldn’t be generalized.

These details would need to be refined through repeated practice and accumulation of data, followed by summarization.

The theory would be derived from practice, which would help verify and improve the theory. Through this cycle, a more accurate standard would slowly emerge.

While holding the purple copper ingot, the shaman and eldest senior brother discussed it. The shaman said it should first be offered to the gods to thank them for blessing the tribe.

The eldest senior brother said they should make a copper shield to become braver when facing prey and enemies. Stone suggested they make some copper pens to better carve on ceramic tablets.

Han Cheng listened, smiling but silent. On the one hand, he was happy for the tribe to have copper, but on the other hand, he knew that many of their wishes—like creating copper shields and pens—could not be achieved until they had tin or lead to make bronze.

In the courtyard, Bai Xue, feeding the silkworms with mulberry leaves from a bamboo basket, suddenly frowned, pressed her hand to her lower abdomen, and showed a look of pain...

Source: Webnovel.com, updated by Aunomay