Time passed as Lingyun controlled the cauldron to smelt the iron. As it was only smelting, the basic use of the Closed Cauldron rune came to effect. The fire was controlled evenly and he barely had to do anything. If he were to truly refine, then the cauldron would only serve to heat up and soften the metal, while the real skill would be used later on.
Lingyun's work in this stage was to oversee the fire and move it a bit based on the actual situation to leave the least number of impurities on the material. He would use his fire control technique to move around the blue earth fire, focusing on different parts of the cauldron.
It was fully closed on all sides and had no openings, from far away, the cauldron looked like a bowl-shaped large stone that was being burned. Naturally the red colour was just appearance, the earth fire couldn't truly burn this mid-stage cauldron that was used by late-stage qi refiners.
After a few hours, the formations were called forth to stop the fire from gushing out, and Lingyun opened the lid on the cauldron, when he deactivated the runes, various openings around the top that were supposed to let out air opened up again.
He used the object control technique to fly out the hot and burning piece of iron. In this state, it was very soft. Lingyun didn't hesitate and carried it to the anvil, then willed the hammer next to it and took it with his hand.
This was the mid-stage black iron hammer, as for the anvil, it was just crafted from a lot of black iron. After being refined, even hammering it wouldn't destroy it, and gradually, it would become denser and more iron would be added. Anvils are treasures that are passed down generation by generation and can even end up being sturdier than any armour.
Lingyun held the hammer and the muscles on his arm started showing, then he raised it and hammered down on the hot blossom. With each hit, more slag, impurities of the ore, flew out. This slag was condensed in the form of black-ish liquid and ash stored at different parts of the iron, like sweat that formed on the surface of the iron.
Each hit created many sparks – these were slag sparks. They flew around the room, damaging the walls a bit. But, after such a long time, the walls were already full of slag, and seemed to have been mysteriously strengthened.
The blossom shrunk a bit with each hit. In this world, the common form of iron were perfect rectangular iron bars, this was the easiest form for further procession. Lingyun on the other hand knew that he would use it directly, so he instead formed a thin iron plate that was one metre long, five centimetre wide and three millimetres thick.
This was the common size of a long sword. The black iron sword forged in the inheritance was forged differently, but Lingyun ignored this and wanted to test his ideas the moment he had the chance. After all, it didn't matter if he failed or succeeded, the value of this knowledge is higher than any experience of refining normally.
Of course this piece of blossom wasn't so little that only one iron place was forced. Instead, a kilogram of iron was used per plate. In total, he created three plates. Any ore that is refined by iron will lose around half its weight. If it wasn't for the efficient usage of earth fire and the cauldron, even retaining 20% of the original ore might be a luxury.
Lingyun repeated the process and gained another three plates. His efficiency was a bit lower because he wasn't perfect with it just yet, but he could gain the common 50% retainment after a few more times. From the original 15 kilograms, he gained 6 kilograms of iron, which is around 40% retainment efficiency.
A kilogram of iron can basically create a single iron sword, which is a weak sword with only three runes. A total of four kilograms can be stacked to create a twelve rune sword. The more It is stacked, the more difficult it will be.
After Lingyun finished, the day basically passed. Smelting the ore took four and a half hour per furnace, while hammering took around half an hour per plate. In total, he spent eleven hours.
This was why he wanted to rest a day afterward – it was simply too strenuous on the body to refine. As for the three day constant refining, that part expended more spiritual and mental power than physical, which could only recover if he truly rested at a time.
His guess was that he could endure working hard for three days, then he would cultivate to restore his spiritual power and advance, while the day after would be used to sleep and recover his exhausted mental energy.
With the way he cultivated, he would basically cultivate two times a week, and both times he would cultivate until his meridians are fully exhausted, which then required two days of rest in between.
He could only do this strict plan because he had a deep knowledge of his body and experimented several times. This 1-1-3-2 week plan was the result of several lifetimes of knowledge. He guessed that for now, it would be the best plan, and he would also recommend it for the future generations if he ever taught anyone.
After all, as long as they weren't cultivation geniuses, everyone would basically encounter bottlenecks, which they couldn't cross without meeting certain requirements. In the qi refining stage, this requirement was the purity of spiritual power. This art of expending spiritual power deeply and then cultivating when it was depleted had extraordinary high purity.
Following this routine, one basically has less bottlenecks and can reach the higher stages in the same speed as those that solely focus on cultivating, as long as they have the same qualifications.
After using this plan for two lifetimes, the result he got was that he could cultivate very steadily. The only negative point of this is that it relies heavily on having the minimum of four spiritual roots – five spiritual roots can't even reach the perfection of qi refining before reaching the age of eighty.
In the world of cultivation, the cultivation speed is generally split into three: first third is the fast progression, also called the youth stage or golden stage, where bottlenecks are less likely to appear and where the meridians basically keep growing.
The second third is the peak stage, where one is constantly honing their power to advance, the power is always at the peak of their current stage, and they can use it as they wish. Although bottlenecks appear more frequently and the body doesn't grow stronger, there is still a high chance of advancing if all preparations are met, one just has to be more careful.
Finally, there is the age of decline, the third category. The first to decline is the blood and essence, the body will gradually age and become weaker, for most cultivators, this reduces the chance of advancement, but doesn't reduce their strength.
The second to decline is spiritual power, which reduces the total reserves an is a great disadvantage. The last to decline is the mental power, the spiritual consciousness, which usually starts just a bit before a cultivator dies, which is called heavens' mercy.
At least this way, cultivators can still remain fully conscious throughout their whole decline stage and still advance if they have an opportunity, they don't have to worry about their soul pulling them down.