Environmental Materials - Titanium

- Jun 19, 2018 -

Environmental Materials - Titanium

1 Environmental Materials - Titanium

 

As the environmental problems such as the haze of the earth become increasingly prominent, it is imperative to study environmental materials. Environmental materials (Environmental Conscious Materials) refer to a group of materials that have excellent performance, are harmonized with the environment, and are environmentally friendly, that is, resources and energy are saved, pollution is small, emissions are low, and renewable and recycled or degradable. A class of materials. The recycling cycle of materials is an important part of environmental materials, and it is a way to save resources and energy and reduce pollution. At the same time, environmental materials also involve the concept of material environmental load. The environmental load of materials is the impact of materials on human survival and living environment throughout its life cycle. These impacts mainly refer to the consumption of resources and energy and environmental pollution. Emissions of waste. Therefore, in the development of environmental materials, including the design, production, use of waste, recycling all stages, we must consider the issue of ecological environment, and strive to reduce the environmental burden of materials.

 

As the titanium surface has formed a stable oxide film (passivation film), stainless steel in seawater, corrosive gases (air pollution, hot springs, acid rain) does not change. It can also be recycled 100%, not easily decomposed, so it does not pollute the environment. Other metals exposed to contaminants can be eroded or corroded, leak metal ions, and enter groundwater, causing environmental problems. The Scheepvaart Maritime Museum recently built in Amsterdam is covered with titanium. Architects and governments took into account strict environmental responsibility when selecting materials for the project.

 

1.1 Titanium Environmental Load

Titanium metal is usually produced by chlorination of titanium ore into titanium tetrachloride (TiCl4), followed by reduction of metal Mg to produce porous sponge titanium, followed by smelting using a vacuum arc furnace (VAR) or electron beam melting furnace (EBR). Ingots. Titanium ingots are processed once (forging or rolling) into titanium workpieces, which are then processed twice to obtain finished products. The environmental load in the production of titanium metal includes the following aspects: (a) from ore to primary metal; (b) from waste to recycling; the energy required for these two applications is expressed as a ratio to steel ( Ti/Fe). (a) Occasions 12.8 (6.5), (b) 2.4 (1.2). This calculation is based on the premise that the primary metal of titanium is sponge titanium, and the number in () is the comparison of the same volume. It can be seen that if titanium is used in the production of titanium, it can be compared with steel. Therefore, the effective use of titanium waste is closely related to the reduction of environmental load.

 

1.2 Status Quo of Titanium Recycling

Titanium scrap can not only be recycled in the titanium industry, but also can be sold as raw materials to steel, iron and titanium. Titanium scrap is an important trading product in the commercial or military strategy like titanium sponge, titanium ingot, and processed materials. It is especially circulated in CIS, UK, USA, Japan and other countries. Titanium waste is classified into new chips and old chips. The former mainly refers to chips, plates or semi-finished products; the latter refers to old waste products such as aircraft parts and heat exchangers. After strict screening, it can be based on the specifications of aerospace materials (ASM). ) Made of processed wood. The former is simple and the latter is more troublesome. In the United States, titanium scrap is used to melt 50% of titanium ingots, and only 2% of scrap is used. In Japan, the use rate of titanium waste is slightly lower than that of the United States. It is mainly exported to the United States as raw materials for smelting. Titanium waste produced by the titanium industry is used almost 100%, but the few who have been circulated to society have not fully utilized it.

 

The following focuses on some of the new applications of titanium as an environmental material

 

2 titanium building materials

 

Titanium-based building materials have been used in Japan for 41 years. Hundreds of cases of buildings use titanium, which has successfully solved the corrosion problems in many heavily polluted areas, cities, and coastal areas. The current market size in this area is about 200 tons, and there are signs of year-on-year increase.

 

New titanium building materials applications are currently in place in the United States, Canada, Scotland, the United Kingdom, Germany, Belgium, Peru, Switzerland, Singapore and Egypt are under construction. Many new projects have been listed in the plan, such as the Paris Air Station has plans to use titanium in two large world-class construction projects. Titanium has also been chosen for use as a material for the Beijing Opera House and the Abu Dhabi Airport's elliptical roof. In the construction of the airport, titanium will be used for the first time in structural buildings. According to physical characteristics, the titanium beam is significantly smaller than the steel beam, making the building more beautiful. In order to meet the needs of the project, Abu Dhabi Airport will use aviation-grade titanium alloy plates as structural supports. In addition, the exterior of the airport will also be covered with titanium panels and glass. Abu Dhabi International Airport is expected to use 1,600 tons of titanium on roofs and structural materials.

 

2.1 Application

 

Titanium House

The earliest titan roof in Japan was the roof of the Zasaka Shrine, and an O.3mm thick titanium plate was used, covering an area of 50m2.The roof of the Tokyo Electric Power Museum, which was completed in 1984, was again made of titanium, and its area was about 720m2. This roof is famous for the first official use of titanium in the construction industry. It adopts a construction method in which the one-lined paving method and diamond paving method, which is one of the copper plate paving methods, are used. The material is selected from JISl pure titanium plate with a plate thickness of 0.3 mm and a titanium volume of about 1 t. In addition, the titanium roof (2330mm2) of the Suma Aquarium of Kobe city, which was completed in 1987, is constructed using a tile roof method. The material used is also a JISl pure titanium plate with a plate thickness of 0.4 mm and a titanium volume of approximately 12 tons. In this construction method, three kinds of gauge plates are preliminarily formed by rolling and then spliced on the roof. Most noteworthy is the use of 0.3mm thick anodically colored titanium panels on the dome of the Fukuoka large open-air stadium built in 1993. The total construction area is 48,500m2, the amount of titanium is 100t, and the roof is movable. The seams are mechanically joined.

 

Titanium outer wall

The application of titanium curtain wall materials with modern architectural style is developing rapidly in Japan. The earliest used titanium outer wall material is the sealing board and the outer wall joint board. In recent years, the outer wall decoration of some large buildings has begun to use thin titanium plates in large quantities. For example, in 1985, the Kameda-Wu props building had a construction area of 190m2; in 1986, Saniron Metal Building (Osaka) used 5t titanium plates, and the construction area was 1,250m2. Gold, yellow, to reduce costs, the use of a 10mm thick calcium silicate board crimped on a 0.6mm thick titanium plate composite board; 1987 Japan Life Insurance Building (Okinawa), the use of titanium is 10.4t, The construction area is 2,500 m2, gray; in 1988, the Tokyo Peacekeeping Wine Building uses 30t titanium plates, and the construction area reaches 2,540 m2. In 1989, the Mito Museum of Art symbolizes the tower, the tower height is 100m, and the outer wall surface has a three-dimensional inclined structure. A panel with a size of 10340mm x ll50mm x 1. 5mm was used for exterior wall decoration, and 25 tons of industrial pure titanium plates were used, with a construction area of approximately 2,500 square meters. The exterior wall of the cartoonist Tezuka Osamu Memorial Museum, which the Japanese took pride in, was colored in 1994. The amount of titanium was 4.1 tons and the area was 173 square meters. In the same year, near the coast, the outer wall of the Oshima branch office building located in the volcanic area also used a 2 mm thick titanium plate, which made the texture excellent. The amount of titanium used was 6 tons. The area was 200. M2. The use ratio of Japan in 1999 and the past 18 years is quite different. The use of titanium on the outer wall is the highest in history. The thickness of the titanium plate used on the titanium outer wall is uneven, 0.6mm thin, 2.0mm thick, and most are 1.5mm. In 1997, Titanium was also used on the outer wall of the Guggenheim Museum in Bilbao, Spain, at an amount of 80 tons.

 

monument

The earliest Japanese titanium monument was the gas tower built by Japan's Western Gas Corporation in 1988 and used a 3.0mm thick titanium plate. In 1999, Japan successively successfully produced the Kogakuitai Park Monument in Kitakyushu. The vibratory machining was used to color the titanium plate and the interior lighting was successfully performed. Composite design using a combination of SUS and steel. The monument of the Kumamoto City Water Works Bureau decorated the emergency water supply pipe, and its blade part can also be rotated. Nippon Steel Yahata Iron Works Labor Hall Monument. The Oita Wisdom Monument floats on a SUS304 grinding ball with a 600mm diameter titanium ball, which is full of high-tech sense.

 

2.2 Historical Places of Interest

According to reports, historic sites such as the Statue of Liberty in the United States, the Parthenon in Britain, the Cathedral of Kern in Germany, and the Kotoji Temple in the northern district of Kyoto in Japan were damaged by acid rain. If you consider corrosion resistance, decorative properties, etc., the use of titanium can better protect these historical and cultural heritage. This is because when titanium is used for cladding of a roof or an exterior wall, its initial material cost is higher than other metals such as copper, but the processing and installation cost of titanium is only 10% higher than that of stainless steel. The corrosion resistance of titanium eliminates the need for repairs and maintenance. From the perspective of total cycle cost, titanium has obvious advantages over other metals. Based on this design concept, titanium can be protected from penetration corrosion for 100 years. Especially in the highly corrosive environment, such as coasts, cities and industrial areas will become more prominent. For example, in 1999, Takatoshi (26m high, 35m wide, and 3m column diameter) of Kashima Shrine in Takasago City, Hyogo Prefecture, Japan used titanium.

 

2.3 Application of titanium construction in China

The use of titanium in China's construction industry is still in its infancy, and it is only 10 years since titanium really entered the construction industry. Although the time is not long, the characteristics of titanium are still being fully utilized in the construction industry in China.