Zhang Maoxiu nodded and said, "Limestone, gypsum and clay can be bought directly at the market. ”

Sun Wufan patted his chest and said, "The matter of the kiln is wrapped up in me. I have a friend who runs a porcelain business and has his own kiln factory, so I went to talk to him and called the master who built the kiln over to build one for Brother Ning Xian. ”

Hearing this, Ning Xiu's heart was a little calm.

There is no problem with the raw materials, and the cement will be made with confidence.

In fact, the production of cement is not as complicated as imagined, it is nothing more than the preparation of raw meal and calcined clinker.

Now there are enough limestone raw materials on the market in Gangneung, not to mention gypsum and clay.

All Ning Xiu had to do was prepare the raw material as soon as possible.

The three of them went their separate ways, and soon Sun Wufan brought the master who was responsible for building the kiln to Ning Xiu's workshop and built a kiln for him. The construction of the kiln was not complicated, and soon the master set up the kiln.

Ning Xiu gave him five taels of silver, and the old master left with the silver in his hand.

At the same time, Zhang Mao ordered the people in the mansion to transport a large amount of limestone, clay, and gypsum to Ning Xiu's soap workshop.

Seeing the unloading of the whole vehicle of Zhangfu's servants, Qilang and Shilang's eyes widened.

"Third brother, what are you doing here? Why did they pour stones, clay, and plaster in front of our workshop? ”

Shichiro plucked up his courage and stepped forward to ask.

Ning Xiu patted Qilang's shoulder and said with a smile: "These are all treasures, the third brother will make a trick for you." ”

After speaking, Ning Xiu instructed the hired workers of his workshop to transport truckloads of limestone, clay, and gypsum to the open space of the workshop.

Although the preparation of raw meal is simple, it is an important part of cement production.

The quality of the cement produced depends largely on whether the raw material is uniform enough.

Ning Xiu instructed his hired men to smash large pieces of limestone into small stones the size of half a palm, and stacked them separately.

The big stones were hammered into small pieces by the workers, and Ning Xiu was not satisfied. In the process of raw meal preparation, the smaller the limestone crush, the more conducive to grinding and stirring. He ordered his hired men to hammer the half-palm-sized stone into four pieces, and then began the next step.

Small pieces of limestone are much easier to grind than large pieces, but the Ming Dynasty did not have machines, and simple manual grinding required effort.

Fortunately, there is a grinding disc, and the fine crushed limestone mixed clay is placed on the grinding disc to push the grinding to save a lot of energy.

Soon the raw material was ground and Ning Xiu ordered the hired workers to transport the raw material to the kiln.

Although the kiln used for porcelain firing is not a professional vertical kiln, it is already the best choice for Ning Xiu at this juncture.

Although he didn't know what Ning Xiu was going to do, looking at the powder as high as a hill, Sun Wufan felt very powerful.

"Let me guess if your next step is to pour this powder into the kiln?"

Ning Xiu smiled and said, "Brother Sun is really too wise. ”

After speaking, Ning Xiu commanded loudly at the hired worker beside him.

"Come and get some charcoal, grind it into powder, and mix it into this raw meal."

In Daming, charcoal burning is the main way to heat the house. Every household will have some charcoal cubes for heating in the winter. Not to mention the Ning family's workshop, which has more than a dozen hired workers.

It took a short time for the hired workers to find a basket of charcoal, and Ning Xiu instructed the workers to grind the charcoal into powder, mix the raw meal, add an appropriate amount of water, and then pour it into the kiln together.

At this time, the raw meal has become a fine ball, which is easier to react completely in the process of high-temperature calcination.

After pouring all the raw meal in, Ning Xiu ordered the kiln to be sealed.

The next step is to make a fire and calcin.

Sun Wufan looked at the excitement and smiled on the side. They really don't understand what they can do by putting a pile of waste into a kiln.

Ning Xiu was not nervous.

He knew that the kiln in which the porcelain was fired could reach temperatures of 1,200 degrees, and sometimes even 1,400 degrees. This temperature is the temperature at which the clinker is fired.

In fact, calcium carbonate will decompose at 800 to 1000 degrees, and the higher the temperature is to ensure that the clinker is fully calcined.

In high-temperature calcination, calcium carbonate is decomposed into calcium oxide, which reacts with silicon oxide and alumina to generate calcium aluminate, calcium silicate, etc.

The main component of cement clinker is calcium silicate-based silicate. The preparation of Portland cement is more than half of the success.

The next thing is to wait.

After about two hours, Ning Xiu ordered the kiln to be opened.

Sun Wufan was very curious, but when he got closer, he was frightened by the heat wave from the kiln.

"Fucking hot, boy, isn't it?"

Sun Wufan patted his chest and stared at the kiln mouth with palpitations.

"Put this clinker and gypsum on the grinding disc and grind it."

The hired men did as they were told. Only this time they grind calcined clinker instead of raw meal.

When the clinker with gypsum is ground into a fine powder, the cement is ready.

Ning Xiu touched the powdery cement and nodded with satisfaction.

"Then it's time to witness the miracle."

Ning Xiu Chong Qilang and Shilang said: "Take two bricks and a basin, and the third brother will play tricks for you." ”

Qilang and Shilang were already dumbfounded, and Ning Xiu only reacted when he said this, and hurriedly went to fetch bricks and basins.

Ning Xiu poured the cement powder into the basin, poured water into it, and stirred it with a wooden stick, and soon got the pasty cement.

Then he dipped a wooden stick in some cement and pasted it between two bricks, and in less than half an hour, the paste of cement condensed. But this is only the initial solidification, and it will take about three hours to fully solidify.

Ning Xiu Chong Qilang, Shilang and Sun Wufan said: "After three hours, everyone will come and see." ”

Shichiro wanted to step forward to touch the bonded bricks, but Ning Xiu drank: "Now the cement has not completely solidified, so you can't touch it." Otherwise, it will affect the bonding effect. ”

Shichiro hurriedly retracted his hand, like a frightened fawn.

Three hours flew by.

Ning Xiu pulled everyone to test the bonding effect of cement.

At this point, the cement has been finalized, and the two bricks fit together perfectly.

Sun Wufan stepped forward and broke it hard, but he didn't move at all, and exclaimed: "This thing is much better than lime mortar." If the lime mortar is not mixed with egg whites and glutinous rice juice, the plasticity is very poor, and even if it is mixed, it does not have a good adhesive effect of cement. What's more, it only takes three hours for the cement to solidify, which greatly shortens the waiting time. ”

For Sun Wufan and Ning Xiu, the most precious thing at the moment is time. It was urgent to repair the outer walls of the palace and the collapsed and dilapidated palace.

Cement is clearly more suitable than lime mortar.

"The most important thing is that the cost of cement is much cheaper than lime mortar mixed with glutinous rice juice, iron sand and egg whites."

Ning Xiu added with a smile.

"Yes, yes!"

Sun Wufan waved his fist excitedly, for him, the cost issue also needs to be considered first.

......

......