US 4,113,833 A · Process for the production of alumina from the mineral component of solid fuels

Process for the production of alumina from the mineral component of solid fuels

OwnerNikolai Ivanovich Eremin, Semen Alexandrovich Tager +10inventors

InventorsNikolai Ivanovich Eremin, Semen Alexandrovich Tager, Vladimir Nikolaevich Kostin, Lev Nikolaevich Bobkov, Mikhail Ivanovich Zaitsev, Nikolai Andreevich Kaluzhsky, Nikolai Stepanovich Shmorgunenko, Abram Zinovievich Jurovsky, Viktor Mikhailovich Kozlov, Fritiof Meerovich Yakhilevich, Mikhail Yakovlevich Shpirt, Vladlen Iosifovich Panin

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Abstract

The invention relates to a process for the production of alumina from mineral component of solid fuels containing aluminum, silicon and iron oxides. The process comprises burning a mixture of a solid fuel with limestone in the following molar ratios of limestone to said oxides: CaO:SiO.sub.2 =2.0, CaO:Al.sub.2 O.sub.3 =1.3-1.8, CaO:Fe.sub.2 O.sub.3 =1.0, at 1700.degree.-1900.degree. C. As a result, a melt is obtained containing calcium compounds: 2CaO.SiO.sub.2, 12CaO.7Al.sub.2 O.sub.3, CaO.Al.sub.2 O.sub.3, CaO.Fe.sub.2 O.sub.3. The melt is cooled and leached with soda solutions for extracting alumina. The sludge remaining after the leaching is suitable for Portland cement production. The invention enables a considerable enlargement of the range of starting products for aluminum and cement industries due to the use of the mineral component of solid fuels, an about twofold reduction of capital investments in the alumina production and reduction of the fuel consumption by 30-40%.

Claims3

Dependent claims

A process for the production of alumina directly from solid fuels containing aluminum, silicon and iron oxides during the burning of said fuels, comprising mixing the solid fuel with limestone with the following molar ratios of limestone and said oxides:

CaO:SiO.sub.2 = 2.0, CaO:Al.sub.2 O.sub.3 = 1.3-1.8, CaO:Fe.sub.2 O.sub.3 = 1.0;
burning the resultant mixture at about 1700.degree.-1900.degree. C to obtain a product containing calcium compounds 2CaO.SiO.sub.2, 12CaO.7Al.sub.2 O.sub.3, CaO.Al.sub.2 O.sub.3, CaO.Fe.sub.2 O.sub.3 in the form of a melt;
cooling the resultant melt to 1300.degree. C at a rate of about 6.degree. C per minute, and from 1300.degree. C to ambient temperature to convert dicalcium silicate contained in the product from the beta-modification to the gamma-modification and leaching the cooled product with a soda solution to extract alumina, leaving a sludge consisting essentially of dicalcium silicates.

Dependencies are inferred from the claim text.