More than 4000 years ago, China made pottery and bronze from clay with less impurities. In the Eastern Han Dynasty (AD 25-220), clay refractories were used as kiln materials and saggers for firing porcelain. At the beginning of the 20th century, refractories developed towards high purity, high density and ultra-high temperature. At the same time, amorphous refractories and high refractory fibers (used in industrial kilns above 1600 ℃) without firing and low energy consumption have been developed. The former, such as alumina refractory concrete, is often used in the inner wall of the secondary reformer of the synthetic ammonia plant in large chemical plants, and the effect is good. Since the 1950s, with the rapid development of atomic energy technology, space technology and new energy development technology, it is required to use special refractory materials with high temperature resistance, corrosion resistance, thermal shock resistance and corrosion resistance, such as oxide, zirconia, refractory compounds with melting point higher than 2000 ℃ and high temperature composite refractories. Refractories in ancient times, middle ages and Renaissance, refractories for blast furnaces, coke ovens and hot blast stoves before and after the industrial revolution, new refractories and their manufacturing technology in late modern times, modern refractories manufacturing technology and its main technological progress, as well as the prospect of the future development of refractories. Refractories appear together with high-temperature technology, Roughly originated in the middle of the bronze age. During the Eastern Han Dynasty, clay refractory was used as kiln material and sagger. At the beginning of the 20th century, refractories developed towards high purity, high density and ultra-high temperature. At the same time, amorphous refractories and refractory fibers with no sintering and low energy consumption appear.
At present, with the development of atomic energy technology, space technology and new energy technology, refractories with high temperature resistance, corrosion resistance, thermal shock resistance and erosion resistance have been widely used. Many factories in China produce refractory products. China is rich in resources. It is for this reason that major foreign investors come to China to show their skills. In Northeast China, there are a large number of refractory suppliers, which leads other foreign investors to question their low export prices. Therefore, in 2003, the EU put forward anti-dumping measures against China's new refractory products, limiting the export of products to the EU. In 2006, in order to protect the massive loss of raw material resources, China reduced and exempted export tax rebates for some industries, which greatly restricted the export of products. However, this can not limit the sales of some foreign brands to a great extent, because they have decades or even hundreds of years of sales and production experience, have greatly occupied the market and created their brand effect on all continents.
1. Improve the level of comprehensive utilization of resources and guarantee capacity.
By 2015, high-end refractories will be basically self-sufficient, with the comprehensive utilization rate of magnesite resources not less than 90% and refractory clay resources not less than 80%. By 2020, the comprehensive utilization rate of the two mineral resources will be higher than 95% and 90% respectively.
2. Strengthen energy conservation and emission reduction.
By 2015, the energy efficiency level of major energy consuming equipment will reach class I, the comprehensive energy consumption of major products will be reduced by more than 20% compared with 2010, the total emission of sulfur dioxide and nitrogen oxides will be reduced by more than 8% and 10% respectively compared with 2010, and the recycling rate of refractory materials after use will not be less than 50%. By 2020, the recovery rate of waste refractory materials will reach more than 75%.
3. Improve industrial concentration.
By 2015, 2-3 furniture enterprises with international competitiveness will be formed and several industrial demonstration bases will be built. The industrial concentration of the top ten enterprises will reach 25%. By 2020, the industrial concentration of the top ten enterprises will increase to 45%.
Workability of refractories includes consistency, slump, fluidity, plasticity, cohesiveness, resilience, coagulability, hardenability, etc.
