In this heavily guarded open place, Qin Feng took thousands of Qin people and began to try to produce black powder in full swing. Li Quzhi, www.biquge.info of the pen %fun pavilion, also proposed that building a grass shed would be more secretive, but Qin Feng categorically vetoed it.

You must know that when saltpeter and sulfur are refined, poisonous gases will volatilize, and only in an open place can we ensure that everyone does not have an accident. Moreover, if you are not careful, black powder will explode, and if you build a grass shed, isn't it easier to burn? Therefore, Qin Feng thought about it, it was most appropriate to send more sergeants to guard it, and don't let anyone in!

The first step is to dissolve the natural saltpeter in clean water, let the sediment and other impurities precipitate, and then filter it clean.

The second step is to add a large amount of plant ash to the saltpeter solution, then pour it into a large pot and boil it several times, and then precipitate and filter it again. In this way, repeated boiling, precipitation, and filtration, more than three times, can be regarded as the second step of saltpeter purification.

The third step is to put the water glue into the nitrate solution and boil it again, and then pour the saltpeter solution into a large urn and let it cool and solidify. The waste water floats on the urn, the mud residue sinks to the bottom of the urn, and the purified saltpeter crystallizes in the center. Finally, remove water and slag, and take out the middle saltpeter to dry.

In this way, the purification of saltpeter ore was completed. After the above process, every 100 catties of natural saltpeter can only be purified into 30 catties of bone white saltpeter.

The purification of sulfur is relatively simple, first mashing the sulfur and picking out sand and other debris. Then put the mashed sulfur into a large pot and boil with water, then filter to remove impurities, pour it into the urn and precipitate for one day, remove the impurity precipitate, and obtain more pure sulfur.

When purifying sulfur, Qin Feng specifically told all Qin people who participated in the purification to cover their mouths and noses with strips of damp cloth to avoid inhaling too much sulfur volatiles and being poisoned.

Qin Feng looked at everyone purifying sulfur and sighed, but unfortunately there is no distillation equipment, otherwise the vapor of sulfur cooking and volatilization will be cooled and condensed, the purity will be higher, and the black powder produced will be more powerful!

Thinking of this, Qin Feng laughed at himself, it was really a lack of human hearts. If you can condense the sulfur gas, not to mention high-purity sulfur, you can also make sulfuric acid yourself! At that time, not to mention black powder, nitroglycerin will definitely be able to be made. It was a high explosive, probably just such a small altar, just a slight wave of his hand, and the incomparably strong city of Kanzaro in front of him would be wiped out in an instant!

What a pity! Although I probably know the manufacturing process of these things, it is a pity that I am limited by the level of science and technology in this ancient world, and the limitations of equipment, etc., what is the use of knowing? You can't make it! It's useless to think too much, let's concentrate on making black powder!

In addition, the last raw material, charcoal, the charcoal needed to make black powder, must be high-quality charcoal with a very low ignition point and high energy. Charcoal is the combustible substance in black powder, and its quality directly affects the burning speed and power of black powder!

So Qin Feng asked Li to send more soldiers to cut off all the branches on the surrounding trees. The skin is scraped off, naturally air-dried, then baked into charcoal, which is then crushed into powder. And the charcoal made from this branch is relatively good!

If Qin Feng's memory is correct, the charcoal needed for black powder in the Central Plains should be made from willow strips that had just budded during the Qingming Dynasty. But now that it's October, where can I find the freshly budding willow sticks? Therefore, Qin Feng could only retreat and replace it with other tree branches, and the effect would not be too bad if he thought about it!

The next step is to put the purified saltpeter and sulfur, as well as the fired charcoal, into a stone mortar or wooden trough, and pound it many times to make it into a fine powder.

Then these three powders are mixed together and put into a mortar in the proportion of 75% saltpeter, 10% sulfur and 15% charcoal. Then add water, mix the mixture into a wet mud form, and constantly pound it with a wooden pestle.

In the process of pounding, it is strictly forbidden to fall sand and gravel debris into the mortar, so as to avoid friction and fire. When these mixtures are almost dry, add water and pound again to make the mixture delicate and well homogenized, and then remove from the sun. This black powder is made!

As for the quality inspection of black powder, it is necessary to select a part of the sun-dried black powder sample and put it in the palm of the hand to burn, and if the black powder is burned and the palm of the hand is not hot, it means that the finished product burns very fast and is considered a qualified product. On the contrary, if the black powder is burned and the palm of the hand feels burned, it is a substandard product. It is also necessary to add water repeatedly and pound until it is finally qualified.

However, the first time Qin Jun made black powder, the process was still in the exploration stage, and there was no experience to talk about. If such strict requirements are made, I am afraid that in two or three months, so many qualified black powder will not be manufactured.

And it was extremely urgent to take the city of Salo, and Qin Feng couldn't care about it so much. As long as it is black powder, even if the quality is poor, it doesn't matter, at most it wins by quantity. I still don't believe it, I can't blow up your Salo City!

While the Qin army was trying to produce black powder, Qin Feng ordered people to dig a tunnel along Sima Li's office, and dug out a confined space ten zhang square under the city wall of Kansaro. According to Qin Feng's assumption, if the purity of the black powder produced was high enough, then in this ten-zhang square confined space, once the black powder burned and exploded, it should be able to blow up the city of Salo. At that time, the Qin army drove straight through this gap, and not only could they save 2,000 Qin people, but they could also capture the city of Saluo in one fell swoop!

On the second day of the Qin army's trial production of black powder, Wang Yanbo, the marquis on duty, came to report that two teams of scouts had been killed last night. According to the scouts who had fled, it was the soldiers of the kingdom of Kansaro. After speaking, Wang Yanbo looked at Qin Feng and thought that the general would definitely be furious this time!

Wang Yanbo expected it to be true, Qin Feng was furious when he heard the news. These Tianzhu people are too ignorant, Qin Jun spared his life, and they killed Qin Jun in turn, is there still such an ungrateful person in the world?

From this one thing, Qin Feng realized that in this era of iron-blooded conquest, his heart was still too soft! At that time, these 20,000 soldiers should be escorted back to the Qin army camp, and then quietly killed!

In this way, there is no need to worry about these people fighting back, nor do you have to waste food to feed them, and you don't have to worry about provoking the heart of the city of Kanzaro to the death. Anyway, he quietly killed in the middle of the night, except for the soldiers of the Qin army, he didn't know the defenders of Saluo City!

Alas! It's all your own fault! Qin Feng thought of the two teams of Qin Army scouts who were killed, and his heart was full of self-blame! It seems that for the sinister human heart and the despicability of human nature, Hong Chou, the military advisor sitting in the city of Kasaro, has a much more thorough understanding than himself!

"Marquis Wang, you have increased the number of Qin army scouts from ten to one hundred, and all those soldiers who see the Scara Kingdom will be killed! If there is a large group of soldiers gathered, you go and inform Sima Zhi, and let him lead the tiger camp of the headquarters to kill them all!"

Wang Yanbo was taken aback when he heard this order, and wondered if this was a bit too much! It's good that there are many scouts so that they don't know where to start, so why bother to kill them all like this?

Seeing Qin Feng's face blue at the moment, and a pair of eyes seemed to be on fire, Wang Yanbo didn't dare to say anything. "Hi" and take the order!

As Wang Yanbo expected, these two groups of Qin army scouts were indeed killed by some of the 20,000 soldiers. On that day, Hong Chou, the commander of the Han Salo army, agitated on the city wall, asking these soldiers to kill the Qin army to prove their loyalty. Some of them did believe it, not only believing it, but also acting on it.

After these people were expelled by Sima Zhi from more than 30 miles, they gathered hundreds of people again and singled out the Qin army scouts. In the end, after throwing dozens of lives away, he successfully killed 17 Qin scouts. In order to compete for these 17 Qin army heads, they killed and wounded dozens of people, and finally 17 powerful soldiers got these 17 letters of approval to enter the city.

Besides, after these 17 people entered the city with the envious eyes of other soldiers outside the city, they were greeted not by a heroic welcome ceremony, but by arrows shot at themselves!

They never expected that they would go to great lengths to kill the Qin army and return to the city with the head of the Qin army, but what they got was such an end! When they were dying, their eyes were wide open, looking at the military advisor Hong Chou in front of them, as if asking, "Why?" Why"?

Of course, Hong Chou would not answer them, but smiled coldly. In Hong Chou's heart, none of the soldiers outside the city can be trusted, even if you come back with the head of the Qin army, you are not trustworthy! Who knows if this head was handed over to you by the Qin army, let you enter the city to do internal response, a few days ago, the Qin army suffered tens of thousands of casualties, and there are not many heads!

All of this had been thought out when Hong Chou first instigated these pawns. What he wants is to let these 20,000 soldiers cause some trouble to the Qin army, it is best for the Qin army to kill these 20,000 soldiers, so that the soldiers of the Cansaro Kingdom in the city can see how brutal the Qin army is, and you will die of surrender! As for the rest, sorry, you guys are overthinking!

Besides, they didn't know about the soldiers outside the city, and they thought that after these people entered the city, they were treated like heroes. Let them continue to dream this dream and continue to kill the Qin army!

Hong Chou looked at the 17 corpses on the ground and showed a kind smile, as if the smile could melt the glacier. It's just that under this smiling face, there is a bone-chilling coldness!