Sail across the sea

Chapter 386 Don't impose your will on others

Seeing Pei Hengxue speechless, Song Xingkang couldn't help but say to Gao Fan:
"Assistant Gao, you only know the concept of four phases and eight states, but do you know that, apart from the ionic phase, there is simply no way to extract rare earth elements from the other three phases—colloidal dispersed phase, independent mineral phase, and lattice impurity phase? This is not just that we cannot extract them; there is no such method in the entire world."

"The pool leaching method proposed by our Zeyan Institute has solved the problem of extracting ionic rare earth elements, which is a great step forward. Leaders from the State Nonferrous Metals Corporation and the Ministry of Geology and Mineral Resources have come to inspect it and have given high praise to the proposed technology."

Essentially, being an office director was not Song Xingkang's forte; he was actually a technician.

Gao Fan turned to Song Xingkang and asked, "Does Director Song mean that we don't need the other three phases of rare earth?"

"Of course it's not that we don't want them, but that existing technology makes it impossible to extract them."

So...maybe we shouldn't.

"I didn't say I didn't want it, so don't force it on me."

"Then let me ask you this: is there any possibility of reusing the slag produced after the pool leaching process in the future?"

Upon hearing this, Song Xingkang was speechless, and Xiao Ping and Pei Hengxue both showed embarrassed expressions.

Those who are familiar with their own situation know best; the biggest problem with the pool leaching process is precisely the issue of slag disposal.

The mineralization principle of ion adsorption type rare earth minerals is simply that rare earth-containing ores are gradually weathered under the action of sun and rain, and the rare earth elements are released and then attached to the clay layer on the surface.

The minerals mined from rare earth mines are actually clays containing rare earth elements. These clays contain both free rare earth elements and rare earth elements that have not yet been released. The latter are the other three phases in the four phases and eight states.

There isn't a good smelting method for this type of clay mineral; you can't just throw clay into a blast furnace to roast it.

Okay, that's how it's done, but it's just too inefficient.

The pool leaching extraction process is a remarkable invention. The method involves digging a pool at the foot of the mountain, sealing the bottom with cement, and then excavating clay containing rare earth elements from the mountain, transporting it down the mountain, and piling it in the pool.

Subsequently, sodium chloride or magnesium sulfate solution is added to the pool. The rare earth ions will undergo a displacement reaction with the sodium or magnesium ions, thus turning the solution into a rare earth chloride solution or a rare earth sulfate solution.

The solution is recovered by using a filter, the slag is discarded, and new clay is added, allowing the production process to continue.

In this process, only rare earth elements in their ionic state can undergo displacement reactions with sodium and magnesium ions. Rare earth elements that have not yet weathered and still exist in mineral lattice form will not participate in this reaction. They will remain in the slag and be dumped into waste rock piles.

Theoretically, it's possible to redevelop and utilize these abandoned mines if better extraction methods are invented in the future. However, from an engineering perspective, this possibility is extremely slim. This is because these abandoned mines have already undergone rare earth extraction, leaving very low concentrations of rare earth elements, making it difficult to meet the requirements for economical development.

This is the biggest problem with the pool immersion process; to put it simply, it boils down to two words: waste.

Another issue with pool leaching is environmental protection. Extracting clay from the mountains damages the topsoil and vegetation. Large amounts of waste slag also occupy land, causing pollution.

In the 80s, people's environmental awareness was not very strong. Local governments, in particular, felt that with thousands of square kilometers of land under their jurisdiction, it didn't matter if dozens or hundreds of square kilometers were polluted. They figured, what's a little bit of vegetation in those remote mountain valleys? In those days, negotiating with local governments about environmental issues was pointless, because they simply didn't care.

But the wastefulness is something no one can tolerate.

In an era when children would be beaten by adults for dropping a grain of rice while eating, wasting minerals more valuable than gold would be considered humanitarianly punishable by being shot for five minutes.

"So, according to Assistant Gao, we're not going to develop rare earth resources anymore?"

Pei Hengxue remained silent for a moment, then said somewhat argumentatively.

Gao Fan looked at Pei Hengxue calmly and said, "I don't believe that Zeyan Institute can't come up with a better extraction method than pool immersion."

As soon as he said that, the expressions on the faces of the others changed again. Xiao Ping, who had been silent until now, suddenly spoke:
"Assistant Gao, just say what you want to say. We're all old-timers, and our thinking isn't as quick as yours, so you don't need to beat around the bush with us."

Gao Fan spread his hands: "I'm not beating around the bush, I'm just telling the truth. I believe that Zeyan Institute must have a more advanced process than the pool immersion method, but I don't know why they are unwilling to share it."

“I see you think you know everything, so how could you not know why we refuse to come up with a better process?” Pei Hengxue retorted directly.

When the two first met, he was wary of Gao Fan's title of "special assistant." Although he didn't like the young man, he couldn't say anything too harsh.

By this point, he could tell that the guy in front of him was just a brat, and he didn't know which brainless leader had given him the position of imperial envoy.

This kind of brat has no idea what tact is; being polite to him is completely useless.

Zeyan Institute is indeed a research institution, but it is also a research institution in the field of heavy industry. How many people in heavy industry aren't hot-tempered? When Lao Pei led a team to the mountains to study ore grades, they encountered some unruly mountain people and even got into a fight with them.

"Then tell me, what better techniques do you have?" Gao Fan asked.

Pei Hengxue glanced at Xiao Ping, and after receiving an approving look, he took a deep breath and said:
“You’re right. We’ve known about the problems with the pool immersion process for a long time, and we’ve been exploring better alternatives.”

“A few years ago, we proposed a process for in-situ leaching, which eliminates the need to transport soil down the mountain. Instead, we spray the mineral layer directly with a solution on the mountain and then collect the solution containing rare earth salts at the foot of the mountain.”

"This method allows for the extraction of rare earth elements in their ionic state without damaging the original mineral layer. If a method for developing other three-phase, seven-state rare earth elements is found in the future, the remaining rare earth elements can be extracted."

“We have conducted small-scale experiments and confirmed that this method has a higher extraction rate of ionized rare earth elements than the pool leaching method. This is because the pool leaching method involves piling up clay together, which results in insufficient ion exchange, while this method can achieve a more complete extraction.”

"In addition, this method avoids damage to the soil and vegetation, and is more environmentally advanced than the pool immersion process."

(End of this chapter)