Basalt fiber: the stone that can build planes and make clothes at the same time

Basalt is a common paving stone in China, but after special means of treatment, it can change its form into a high-performance fiber material with a metallic luster - basalt fiber. The strength of this fiber is 5 to 10 times that of steel, but the weight is about one-third of the same volume of steel, compared with the previous, the application value is greatly enhanced. Therefore, some people imaginatively call its manufacturing technology "stone into gold".

High-quality development can not be achieved without the support of strong new materials. During the "Thirteenth Five-Year Plan" period, the country listed basalt fiber as one of the four key fiber materials, and the "Key New Materials First Application Demonstration Guidance Catalogue (2019 Edition)" implemented earlier this year also included basalt fiber as a key strategic material again.

In recent years, China has accelerated the development of basalt fiber manufacturing technology and achieved many new results, providing strong support for the development of new infrastructure, intelligent manufacturing and other emerging industries.

From ordinary paving stones to high-tech fiber materials

People who often watch martial arts dramas will be impressed by a kind of magical armor in the drama: they are made of "gold silk", wear not only light, but also invulnerable to swords and guns, is quite a mysterious treasure. Nowadays, researchers have really made this mysterious armor, they are not only tough and light, but also given more powerful functions.

For example, firefighters in the fire, their "armor" to heat insulation, high temperature; astronauts in space, their "armor" to block radiation; ships sailing in the sea, their "armor "both toughness, but also anti-corrosion; bridge through the north and south, their "armor" is strong and wear-resistant, but also not heavy ......

The production of such "armor", common metal materials have been unable to meet the above requirements for use. But a high-tech fiber material - basalt fiber can do.

The basalt ore is crushed and ground, then poured into a furnace, where the powder is heated at over 1200 degrees Celsius and turned into a liquid state. After being clarified and cooled and homogenized, these solutions are passed through a leaky plate and drawn like marshmallows into a fine filament of 7 to 20 microns under the high-speed traction of a drawing machine, which is basalt fiber.

Although the diameter of a basalt fiber filament is only one-third of that of a hair, its strength is twice as strong as that of the same diameter steel fiber, more resistant to corrosion than alloy, and can withstand temperatures up to 500 degrees Celsius. Twisted basalt fibers resemble cotton threads and can be used for protective clothing when woven into cloth. Basalt fibers and polymer matrix using a specific process of molding the resulting fiber-reinforced composite materials have a high strength ratio, can be used to manufacture tanks, ships, aircraft shells. What's more, basalt is a natural ore, and the process of manufacturing basalt fiber is basically free of harmful substances, so there is very little pollution to the environment.

Basalt fiber has a wide range of applications, and can be used in aviation, aerospace, construction materials, road and bridge construction, naval shipbuilding, wind power generation and other fields.

Hou Jinlong, deputy director of the expert committee of the China Highway Society, introduced, "Basalt fiber for roads can effectively reduce the disease of cracks and rutting of pavements, greatly extend the service life of pavements, and have significant effects in improving and enhancing the high-temperature stability and low-temperature crack resistance of pavement structures."

At the end of 2018, the famous Nanjing Yangtze River Bridge was closed for maintenance and opened to traffic again. The upgraded Nanjing Yangtze River Bridge then used basalt fiber in key areas. Basalt fibers have excellent tensile reinforcement properties, and bridge construction workers bonded basalt fibers to concrete members to strengthen the bridge, making it lighter and longer-lasting. In addition, basalt fiber is also used in the construction of China's Hangjinheng Expressway, Zhengwan High Speed Railway and the South China Sea islands.

"Basalt fiber technology has appeared only 30 years ago, and the application of the technology is in its infancy in countries around the world." Liu Jiaqi, a researcher at the Institute of Geology and Geophysics, Chinese Academy of Sciences, introduced that the basalt fiber produced worldwide now cannot even meet one percent of the demand. At the same time, China is very rich in basalt resources, with a large number of basalt mineral resources distributed in Gansu, Heilongjiang, Xinjiang, Shanxi and Sichuan. If most of these stones used for paving are fully utilized and turned into fiber materials, will have a great role in promoting the new materials industry.

Dozens of hurdles need to be overcome to make the ore "obey"

Turning hard stones into fibers by melting and drawing them is not an easy task, especially when you are dealing with a stone that is not so "obedient".

Ma Pengcheng, a researcher at the Xinjiang Institute of Physical and Chemical Technology, Chinese Academy of Sciences, who has been working on basalt fiber research for many years, told reporters, "First, basalt ore is a natural product with a volatile chemical composition, so the performance of basalt fiber in the preparation itself is not stable. Second, from basalt ore to basalt fiber needs to go through two processes: melting and fiber forming. In the process of basalt melting, many minerals in the ore gradually melt, once there is not completely melted crystalline phase, it is easy to form secondary crystallization nuclei; in the process of basalt fiber forming, the basalt melt also has different degrees of precrystallization tendency. This precrystallization needs to be avoided as much as possible, otherwise it will affect the characteristics of the fiber and the quality of the final product."

Proudly, China is one of the few countries in the world that has mastered basalt fiber drawing production technology. Ma Pengcheng said, although China's research on basalt fiber started late, but after continuous and difficult exploration, researchers and related enterprises have overcome many manufacturing technology difficulties to achieve mass production of basalt fiber and form a certain market scale.

Basalt melt drawing all electric fusion pool kiln technology is China's independent innovation technology. June 22, China has completely independent intellectual property rights of the world's first set of continuous basalt fiber 10,000 tons pool kiln production line was officially put into operation. July 1, basalt fiber 2400 holes leaky plate drawing intelligent pool kiln production line also ignited and put into operation.

Ltd. where the 10,000-ton pool kiln production line is located, the technical department manager Li Jun introduced, compared with the traditional process, the pool kiln method of operational stability, high degree of automation, which allows a higher melting rate of rock, can reduce production costs by more than 40% year-on-year, greatly improving product quality and production efficiency.

"The completely self-designed melting kiln is the most core equipment of the whole production line." Li Jun said, "The so-called 'all-electric melting pool kiln' refers to the fact that the kiln uses all electric energy as the energy source in the melting process of mineral materials, and uses internal heating to complete the rock melting by placing electrodes inside the molten basalt."

In order to solve the problem of instability of basalt in the melting process, researchers of relevant enterprises have conducted a lot of research on basalt fiber pool kiln drawing technology, experiencing countless failures and numerous attempts to conquer dozens of problems. For example, in order to make the basalt more stable in manufacturing, the technical personnel make preferential selection through big data in the ore raw material selection stage to ensure the high grade of ore raw material. In the stage of crushing and making materials, the stability of raw material mineral components is enhanced by the world's first technical way of aerodynamic crushing and homogenization of raw materials. In the melting stage, the problem of small melting capacity and poor uniformity of basalt mineral raw materials is solved by designing a large unit pond kiln; the problem of high melting temperature of basalt is solved by using a combination of oxyfuel combustion and electric flux.

In order to reduce the cost of basalt drawing and improve the quality of fiber yarn, the technical staff worked on the key equipment for turning the solution into fine yarn - the leakage plate, striving to achieve not only one dragging multiple leakage plates in the drawing process, but also to increase the number of holes in each leakage plate as much as possible.

"New materials have only started to emerge in recent years, we do not have much foreign mature technology to introduce, destined to independent innovation. Through the means of science and technology, let basalt such a low value-added products to give its vitality, this is the ideal and mission of our scientific researchers." Ma Pengcheng said.

Some of China's new materials technology innovation has entered the "no man's land"

Materials are the foundation of the manufacturing industry, shaping the bones of a great nation.

Chinese Academy of Engineering academician Gan Yong said, to a new generation of information technology, new energy, intelligent manufacturing and other emerging industries represented by the higher requirements for materials, new materials research and development of unprecedented difficulty, the increasing difficulty of innovation. It can be said that some of China's new materials technology innovation has entered the "no man's land".

In the case of basalt fiber, how to make this material more powerful performance and more affordable through technological innovation is the next step for researchers and manufacturers to solve the problem.

In Xinjiang, where basalt deposits are abundant, the Xinjiang Institute of Physical and Chemical Technology of the Chinese Academy of Sciences (hereinafter referred to as Xinjiang Institute of Physical and Chemical Technology) has established a large database of basalt fiber materials in China based on domestic geographic and geological considerations, forming a data sharing and big data analysis in the field of basalt fiber, and the database results can be used to guide the fiber drawing process and provide technical feasibility for developing high-performance basalt fiber materials.

Xing Dan, a research assistant at Xinjiang Institute of Physics and Chemistry, introduced that previously, basalt fiber was a non-conductive fiber and thus was considered as an insulating material by default. However, in recent years, researchers have used the metal elements contained in basalt fiber itself to achieve the controlled growth of carbon nanomaterials on the fiber surface and obtain conductive fiber materials, overturning the traditional concept of basalt fiber as an insulator, increasing the functional value of basalt fiber and expanding the application of the material in electromagnetic shielding and other fields.

Meanwhile, with the advancement of China's lunar exploration project, researchers have been exploring the feasibility of making continuous fibers from the basaltic lunar soil distributed on the lunar surface. The research results show that the lunar soil has similar chemical composition, mineral phase composition and similar fiber-forming behavior with the basaltic ores of the Earth.

Not only basalt fiber, information shows that in recent years, China's new materials innovation system is becoming more and more perfect, manufacturing innovation centers, technology innovation centers, state key laboratories, industrial bases, etc. have reached about 400, and related innovative achievements continue to emerge.

In May this year, Southwest Jiaotong University and other research teams developed a high-strength flame retardant glass fiber composite materials. This material can be applied in the field of rail transportation, by giving track power, emergency facilities "on" the new material of high-strength flame retardant glass fiber "armor", the strength of the track, flame retardant, corrosion resistance, insulation, thermal conductivity, water resistance and other performance indicators can achieve greater Upgrade.

Ma Pengcheng said, in fact, new materials do not have to be a brand new substance, through the means of science and technology to the traditional material innovation transformation, is also a kind of new materials. With the advancement of new materials research, in the future, not only stones, plants, metals and other commonplace things in daily life can be magnificently transformed, bringing a different and new feeling to our lives. (Yahui Wang)

Academician of the Chinese Academy of Engineering, Vice President Gan Yong: new materials technology is a chassis technology

Central Commission for Discipline Inspection State Supervision Commission website Wang Yajing

New materials are the material basis to support modern manufacturing industry and one of the seven strategic emerging industries of the country. When a new round of scientific and technological revolution and the transformation of China's economic development formed a historic intersection, the development of China's new materials industry ushered in a rare historic opportunity, but also faces a huge challenge of "not catching up or out". What kind of development situation does China's new materials development face? Why say "catch up or out"? Recently, the reporter on the relevant issues connected to the Chinese materials experts - Chinese Academy of Engineering academician Gan Yong.

Reporter: General Secretary Xi Jinping pointed out during his inspection in Shanxi that the new materials industry is a strategic and basic industry, as well as a key area of high technology competition, we must catch up and catch up. Why do you say that new materials is a strategic and fundamental industry?

Gan Yong: Everything is made of matter, and one step further development of matter is materials. Our life can not live without materials, the development of our real economy, the development of technology, more inseparable from the support of materials. Materials industry is the material basis of national economic construction, social progress and national defense security. Especially now, the cross-fertilization of industrialization and information technology makes the whole process of industrialization accelerate, and it can be said that mankind has entered a new period. In order to accelerate development in the new period, we must pay attention to the role of materials. Because a generation of materials determine a generation of technology, the development of technology is first of all the development of materials. After the development of a new generation of materials, in order to drive a new generation of technology, a new generation of equipment and equipment, a new generation of engineering development. For example, after the emergence of superconducting materials, we can produce a series of high-end medical devices; a new generation of semiconductor materials with good, 5G communications and other further development is possible. Therefore, new materials is a strategic and fundamental industry.

There are two kinds of new materials, one is that we have discovered some new uses, new functions of the material, one is to upgrade the traditional materials, so that it produces new performance. At present, China is at the forefront of the world in the production of more than a hundred kinds of materials such as steel, non-ferrous metals, rare earth metals, cement, glass and chemical fibers. After these traditional basic materials are prepared by advanced technology, they can be turned into a new material, which can then be turned into devices, modules and other products we need for the construction of some projects. This change in material properties is what produces new industries, which in turn produces new equipment and new national strength. Just like our body to grow, we must first have bones and muscles. So, new material technology is a chassis technology.

More importantly, new materials also have a pioneering leading role. All of the advanced industries, the development of advanced equipment, high-end equipment, the emergence of the first to have to meet its advanced function of the material. So once the performance of the material is enhanced, then other industries also follow the development. Materials should be the first. And because it has a guide, which is strategic.

You see we used to research and manufacture some high-performance aircraft, sometimes the aircraft research, and then to develop supporting materials, and then you will find that it can not get up, because it is too late. Because the cycle of material development is longer than the cycle of technological development, your overall design of the aircraft out, the specific materials do not work, the aircraft quality level will not go up.

Reporter: What has our country achieved in the development of new materials or have what advantages? What are the urgent need to complement and improve the place?

Gan Yong: At present, our country has established a relatively sound materials system, the basic materials required by the national economy we almost have. But in the new materials, especially many high-end materials, including some key composite materials, new energy materials, semiconductor materials, rare earth functional materials, information display materials, biological medical materials, we do not have. But happily, our country in the new materials are also struggling to catch up, such as carbon fiber, graphene and other development is very fast, and then for example, our super steel, now popular application is also doing very well.

In addition, the gap between us and some developed countries in new materials also lies in the improvement of material performance. Modern economic and social development needs more and more sophisticated industrial equipment, these precision industrial equipment and the need for ultra-high purity, high strength and special performance materials, but also requires low cost of materials. Especially in strategic industries such as aerospace, the materials required by foreign countries will not sell us, they will only sell us aircraft such finished equipment. So once we do not have production capacity in this area, it will be "stuck" by others.

So I feel that China still needs to make efforts in key strategic materials, especially to strengthen the ability of independent innovation. Because many new materials and new materials production technology are invented abroad, so many new materials standards are set by foreign countries. We need to have our own technology, in order to have their own voice in new materials.

Reporter: Some people believe that the next five years will be a key period for the development of new materials in China from big to strong. In this regard, what do you think?

Gan Yong: Why do people say that the next five years is a key period for the development of China's new materials from big to strong? My personal view is that this year is the "Thirteenth Five-Year Plan" closing year, is also built a moderately prosperous society in the final year, our country into the "Fourteenth Five-Year Plan" after, in fact, just the world's fourth industrial revolution period. The fourth industrial revolution is an industrial revolution with graphene, gene, virtual reality, quantum information technology and other technological breakthroughs. The first three industrial revolutions, China has not caught up, all missed. So this time, we can not be left behind.

As I said earlier, materials are the foundation, so materials must first breakthrough, our other high-tech industries can be bigger and stronger. I think, the next 10 to 15 years, our country's new materials industry development must move into the international first-class square, to achieve the transformation from a large material country to a strong material country, we can mention these concepts of manufacturing power, because the material is not strong, the other no way to really strong up, and finally still subject to others. Materials do not break through, we are in the fourth wave of the industrial revolution and to be left behind.

In addition, we now have the conditions to turn from a material power into a material power. For example, we have a large number of researchers in the field of materials. Materials development is characterized by a long cycle, especially to study a new material, not only a long time, but also a large investment, but also can not immediately obtain the application. The good thing is that our researchers are not afraid of hardship, our scientific research talent strength is sufficient, more than 150 universities in our country with materials, the field of new materials of the two academies have more than 200 academicians, new materials of the state key laboratories more than 60, these complete system has become a comprehensive promotion of our new materials industry development support. In addition, we have a vast domestic market for materials, and the market demand is huge. The economy will drive the development of numerous technologies, which in turn will support our research in the field of new materials. For example, we are now adjusting our energy structure and renovating our coal-fired technology, which requires tens of millions of heat-resistant alloys and heat-resistant steels. We also have deep-sea mining, which requires various corrosion-resistant alloys and desalination membrane materials.

I feel that in about 5 years we can enter a state of basic security in materials; in about 10 years, we can be strong in some materials fields. For now, we have to hurry up and must keep up; if we don't, we will be out.