Development History Of Refractory Raw Materials

Since the Bronze Age, humans have used clay minerals to build copper smelting furnaces, and in some places, local refractory stones have been cut into pieces to build furnaces. In the iron-making site of the Eastern Han Dynasty in the suburbs of Zhengzhou City, China, an iron-making furnace lining knotted with clay plus silica sand, rice husk or crushed charcoal was found. In 1615, England made a crucible for melting glass with Stubble clay, and soon made a refractory brick and successfully tried it on a copper smelting furnace. Due to the expansion of the kiln volume, the damage is too fast with this kind of brick. Use silica sand and binder lime instead, and achieve success in use. In 1822, W.W.Young made silica bricks by adding lime to silica sand, and then made silica bricks with silica rock. In 1838, American J.L.Norton used kaolin as raw material and calcined clinker to make clay bricks. In 1855, Bessemer invented the converter steelmaking method. In 1856, Siemens invented the reverberatory furnace (the current open hearth furnace) with refractory bricks and a regenerator, and the pig iron-ore steelmaking method appeared. However, limited by the properties of refractory bricks at that time, only low-phosphorus pig iron could be used to make steel, that is, the acid steelmaking method. It was not until 1879 that Britain successfully used calcined dolomite and tar to knot the bottom of the furnace that the alkaline steelmaking method began to be used.
In 1868, Caran proposed that magnesite is a kind of refractory raw material, and introduced the method of making bricks with magnesite. Kal Spatlon in Austria discovered a large deposit of magnesite in Styria. This ore is a mixture of magnesite and siderite. Because of its high iron content, it is easy to sinter. In Europe, this kind of sintered magnesite mixed with tar has been successfully used to tie the bottom of furnaces, and it has been rapidly popularized.
The bottom of the furnace is made of alkaline refractory material, and the upper part of the furnace is made of acidic refractory material. The contact zone between the two is severely eroded during use, and finally the two are separated with chrome ore to achieve success. In 1886, Britain succeeded in making bricks from chrome ore. In 1915, the patent of Wenham in the United Kingdom introduced 20% to 80% of chrome ore and sintered magnesia to make magnesia-chrome and chrome-magnesia bricks. But until the 1930s, there were only magnesia-chrome or chrome-magnesia bricks sold as commodities in Britain, the United States, Germany and other countries.
Around 1915, the A.Radex brand magnesia bricks made in Austria improved the spalling resistance of the magnesia bricks by adding a small amount of Al2O3. After research, it was found that the bricks formed magnesium-aluminum spinel (MgO·Al2O3) minerals during firing. Because the magnesium-aluminum spinel minerals have a small linear expansion coefficient and high structural strength, the spalling resistance of the bricks was improved.
In 1821, bauxite or bauxite or bauxite ore was discovered in Le Box, France, mainly composed of gibbsite, gibbsite and other minerals.
Corundum is a natural mineral, its hardness is second only to that of diamond, and its color is bright. It was called a gemstone by human beings for a long time ago, and it is rare in nature. In 1896, the German Mocat invented the artificial corundum method.
In 1924, the British Bowen et al. discovered the new mineral 3Al2O3·2SiO2 in the clay material fired at high temperature, and soon published the equilibrium state diagram of the Al2O3-SiO2 system. This mineral was subsequently discovered on the Isle of Mull in England, and Bowen named the 3Al2O3-2SiO2 mineral mullite. Synthetic mullite was made by electric melting in 1926, and developed into sintering mullite in 1928.
Although the Germans extracted magnesium hydroxide from seawater as early as 1881, the production of refractory raw material synthetic magnesia from seawater on an industrial scale was started by the British Stitley Company in 1938.
At the beginning of the 20th century, silica was fused into quartz glass (that is, fused quartz), and it was successfully used in the immersion nozzle of continuous casting in the 1960s.