History Of Refractory Raw Materials

Since the Bronze Age, humans have used clay minerals to build copper smelting furnaces. In some places, local refractory stones are used to build furnaces. An ironmaking furnace lining knotted with clay, silica sand, rice husk or broken charcoal was found at the East Han ironmaking site in the suburb of Zhengzhou, China. In 1615, Britain made a crucible for melting glass from Stubborog clay, and soon made a refractory brick and tried it successfully on a copper smelting furnace. Due to the expansion of the kiln volume, the bricks are damaged too quickly. It is successful to use silica sand and binder lime instead. In 1822, W.W. Young made silica brick by adding lime to silica sand, and then made silica brick from silica rock. In 1838, J.L. Norton, an American, used kaolin as raw material and calcined it into clinker to make clay bricks. Bessemer invented the converter steelmaking method in 1855, and Siemens invented the reverberatory furnace with refractory bricks and a regenerator (now the open hearth furnace) in 1856, and the pig iron-ore steelmaking method appeared. However, limited by the nature of refractory bricks at that time, only low phosphorus pig iron can be used for steelmaking, that is, acid steelmaking method. It was not until 1879 that the British succeeded in tying the bottom of the furnace with calcined dolomite and tar that the alkaline steelmaking process was used.
In 1868, Caran proposed that magnesite is a refractory raw material, and introduced the method of making bricks from magnesite. Kal Spatlon, Austria, discovered a large deposit of magnesite in Styria. This kind of ore is a mixture of magnesite and siderite. Due to its high iron content, it is easy to sinter. In Europe, this kind of sintered magnesite mixed with tar has been used successfully to tie the bottom of the furnace and has been rapidly promoted.
The bottom of the furnace is made of alkaline refractory, and the upper part of the furnace is made of acid refractory. The corrosion is serious in the contact zone between the two, and then the chrome ore sand is used to separate the two successfully. In 1886, Britain successfully made bricks from chromite. In 1915, the patent of Werham, England, introduced that magnesia-chrome and chromium-magnesia bricks were made by using 20%~80% chromite and sintered magnesia. However, it was not until the 1930s that magnesia-chrome or chromium-magnesia bricks were sold as commodities in Britain, the United States, Germany and other countries.
Before and after 1915, the spalling resistance of the magnesia bricks of A. Radex brand made in Austria was improved by adding a small amount of Al2O3. Later, it was found that magnesia-alumina spinel (MgO · Al2O3) minerals were formed during the firing of the brick. Because of the low linear expansion coefficient and high structural strength of magnesia-alumina spinel minerals, the peeling resistance of the brick was improved.
In 1821, bauxite, or bauxite, was discovered in Lebox, France. It is mainly composed of bauxite, gibbsite and other minerals.
Corundum is a natural mineral, its hardness is second only to diamond, and its color is bright. It was called a gem by human early, but it is rare in nature. In 1896, German Mokat invented the artificial corundum manufacturing method.
In 1924, the British man Bowen and others found a new mineral 3Al2O3 · 2SiO2 in the clay material fired at high temperature, and soon published the equilibrium state diagram of Al2O3-SiO2 system. Later, this mineral was found on the Island of Moore in England. Bowen named 3Al2O3-2SiO2 mineral mullite. Synthetic mullite was made by electrofusion in 1926 and sintered mullite in 1928.
Although the Germans extracted magnesium hydroxide from sea water as early as 1881, the production of synthetic magnesia from sea water as refractory raw material on an industrial scale was started in 1938 by the British Stetley Company.
At the beginning of the 20th century, silica was fused into quartz glass (i.e. fused quartz), which was successfully used in the submerged nozzle of continuous casting in the 1960s