Five days later, the Fish Hill Workshop.

Liu Juntao, accompanied by Tang Yu and Ma Lijun, walked into the glaze workshop at the foot of Yushan Mountain.

This glazed workshop is surrounded by trenches and endless reeds on all sides, making it difficult for outsiders to find it.

Moreover, Chang Hongdao, who was stationed here, also specially arranged for his subordinates to ambush and patrol nearby, so as to prevent any outsiders from approaching the Liuli Workshop.

After walking into the glaze workshop, Liu Juntao first checked the layout of the workshop, as well as the equipment and raw materials for firing glaze under the guidance of Ma Lijun.

After reading it, Liu Juntao was very satisfied, and said to Tang Yu and Ma Lijun with a smile: "Very good! It seems that our glass workshop is ready for everything, only owes the east wind! ”

Tang Yu and Ma Lijun both laughed together.

Tang Yu even said: "Since this is the case, then please ask Mr. Lian to give us a chance to borrow the east wind!" ”

Ma Lijun also said: "Yes, Mr. Lian, to be honest, the craftsmen here in the workshop have basically not fired glass, most of them are craftsmen who burn pottery and porcelain, and everyone is looking forward to teaching us skills!" ”

Liu Juntao smiled and said, "Okay! I'm here today to pass on the art of firing glass to the craftsmen. Master Ma, you will gather your backbone masters, and I will explain to you on the spot! ”

"Good! Mr. Lian, I'll call someone right away! ”

After a while, Ma Lijun found eight craftsmen, and they all followed Liu Juntao to the fire where the glass was burned, each holding charcoal and straw paper in their hands, all like students, for fear of missing any technical principles.

In later generations, Liu Juntao once visited a glass factory because of his university major, and systematically listened to the technical master explain the entire process of firing glass.

Moreover, in the later generations of information developed, how to fire glass, even optical glass is no longer a secret technique, as long as there is a computer can be found out in detail.

In order to burn transparent optical glass, three conditions must be met:

One is to have suitable refractory materials, preferably refractory bricks that have reached the steelmaking level, and now the War Bureau has already had the ability to refine steel, so this condition has been met, Liu Juntao has asked Zhang Baigui to send a batch of refractory bricks in advance, and the furnace on this side of the workshop has been built.

The second condition is to use quartz sand with high purity as the main raw material for firing glass, which is a bit difficult in Daming at this time, so it can only be selected, powdered and calcined for general quartz sand.

Prior to this, Liu Juntao had arranged for the Ministry of Commerce to start from two aspects: one was to raise quartz sand through purchase, but the quantity was limited and expensive; Another way is to collect materials on the shores of large and small lakes in Yushan Reeddang and Dongping Lake Reedang, which can temporarily meet the needs of the workshop.

The third condition is to add lead oxide in the calcination process, and the glass industry in ancient China basically only produced colored glass, the reason is that the role of lead oxide has not been mastered. Lead oxide was still called lead yellow in Daming at this time, which was not a rare thing and could be easily bought.

In addition to the raw materials, the glass furnace also had to be constantly stirred during production, so the glass furnace also needed a new design. Tang Yu has organized manpower to build five new glass cellars according to the design drawings given by Liu Juntao, which can fully ensure the output and quality of glass.

At this time, Liu Juntao looked at the people who were looking forward to it, and began to explain: "Glass is what we usually call glass, the main raw material is quartz sand, and then soda ash, limestone and feldspar need to be added in the calcination process, of which only soda ash is the most difficult." ”

"In the vicinity of our Yushanji, the large amount of trona that can be supplied for firing glass mainly comes from alkali lakes and solid alkali ore. Especially the alkali lake, at the foot of our fish mountain and around Dongping Lake, it can be said that there are all over the alkali lake, so we don't have to worry about this. ”

Liu Juntao stood in the crowd and talked about everything, and everyone was carefully recorded.

“…… Next up is calcination! Quartz sand, soda ash, limestone, feldspar and other block raw materials are all finely crushed to make the wet raw materials dry. Subsequently, in order to ensure the quality of the glass, we also need to find a magnet and remove the iron of the raw materials......"

“…… In addition, there is a big problem in the firing stage, that is, the temperature of the fire needs to reach the level of refining steel. Therefore, the fuel for calcining glass also uses coke used in steelmaking......"

Fortunately, when Liu Juntao was refining steel, he had already had some enlightenment, and handed over the method of making coke to Zhang Baigui in advance, so that the War Bureau had already reserved a lot of coke.

At this time, Zhang Baigui also brought a lot of coke to the glaze workshop for use.

In order to ensure the timely supply of coke, Tang Yu also built a special furnace for burning coke in the glaze workshop.

"When the solution flows out, it will be connected to a special iron mold, and after it is cooled and set, it will be flat glass of various shapes!"

Speaking of this, Liu Juntao was already dry-mouthed, took a sip of water, and continued: "The next thing is silver plating!"

Liu Juntao talked endlessly for more than an hour before he finished the entire process of firing glass.

Ma Lijun, Tang Yu and several craftsmen have long been shocked by the craftsmanship that Liu Juntao said, and everyone looked at Liu Juntao with admiration and admiration.

At this time, Tang Yu suddenly remembered something, so he asked, "Mr. Lian, do we only burn flat glass?" ”

Ma Lijun next to him also reacted and asked, "Yes, Mr. Lian, why don't we burn glass bottles and glass cups?" If there are more styles like this, the income of our workshop will skyrocket! ”

In fact, the main purpose of Liu Juntao to build this glazed workshop is not to make money, and increasing the income of Yushanji is only a secondary purpose.

Liu Juntao's main purpose is to accumulate technology for the future artillery unit!

At this time, the artillery was only an auxiliary firearm, and the shooting accuracy was very poor, and it could only bombard the enemy's large array or the city wall, and it could not shoot at a specific target at all!

Because at this time, the Ming Dynasty, and even Western countries, lacked one thing, that is, optical glass!

With optical glass, Liu Juntao can mass-produce artillery sighting equipment, and he can mass-produce monoculars!

Don't underestimate these two things, these two sharp weapons can change the trend of the battlefield, and even turn the tide of the battle!

Because of this, Liu Juntao abandoned glass bottles, glass cups and other products, but specialized in the production of flat glass, ready to climb the technology tree of optical glass!

Of course, it was too early to talk to Tang Yu and Ma Lijun about this at this time, and it was impossible for the two of them to understand what a precision strike was.

Therefore, Liu Juntao casually found an excuse and perfunctory, and Tang Yu and Ma Lijun stopped insisting when they saw this.

In the end, Liu Juntao said to Tang Yu, Ma Lijun, and several craftsmen: "Now the full set of skills of firing glaze can only be known by a few of you, if anyone tells this set of techniques, I will be severely punished!" ”

When everyone heard this, they were all stunned.

"In addition, the entire workshop must implement the assembly line production I have formulated, and if anyone steals the skills, you will hand over the thief to Chang Hongdao, and Chang Hongdao will take the thief away and execute him!"

Hearing this, everyone's hearts were awe-inspiring, and they nodded their heads one after another.

Liu Juntao explained some details of things, and then handed over his vision of optics to Ma Lijun, and instructed him to step up research and development after the glass workshop was on the right track.

"The glass workshop can be put into production immediately, and the samples produced will be sent to Yushanji after a month, and I want to check it out for myself!"

Ma Lijun nodded heavily and said, "Don't worry!" ”

"That's it! Let's go to the shochu workshop on the hill now! ”