Other

Vsesojuzny Nauchno-issledovatelsky I Proektny Institut Aljuminievoi,

Nikolai S Shmorgunenko

Ivan M Kostin

Isaak A Zatulovsky

Khoren A Badaliants

Leonid I Finkelshtein

Nikolai A Kaluzhsky

Nikolai Ivanovich Eremin

Raisa V Ivanova

Alexandr V Eljutin

Alexei I Alexeev

Nikolai A Novikov

Viktor M Sizyakov

Alexandr V Peredereev

Arkady I Zazubin

Tatyana D Ostapenko

Georgy P Tkachenko

Anna E Danilina

Mikhail Ivanovich Zaitsev

Leonid M Butorin

Elena L Shalavina

Arkady A Belsky

Askar M Kunaev

Vladimir Nikolaevich Kostin

Evgeny A Isakov

Pavel S Vladimirov

Vladimir V Andreev

Valentin I Korneev

Semen Alexandrovich Tager

Fritiof Meerovich Yakhilevich

Anatolia I Simanova

Teodor G Milberger

Petr F Minin

Greogy I Lazarev

Mikhail Yakovlevich Shpirt

Vladimir V Krasavin

Gennady A Romanov

Lev Nikolaevich Bobkov

Garegin A Peikarov

Anatolia T Simanova

Vladlen Iosifovich Panin

Natalya V Tishevetskaya

Leonid F Bilenko

Oleg V Alexeev

Ioan V Davydov

Vitaly L Aronzon

Gennady A Panasko

Boris A Kuzmin

Viktor Mikhailovich Kozlov

Avgusta I Samoilova

Vladislav A Krochevsky

Ljubov B Samaryanova

Larisa I Sinelnikova

Evgeny M Steshenko

Abram Zinovievich Jurovsky

Jury N Evseev

Petr V Fedorin

The cement of the invention comprises chemically combined oxides, percent by mass: CaO, 50 to 60; Al.sub.2 O.sub.3, 28 to 37; Fe.sub.2 O.sub.3, 0.01 to 1; SiO.sub.2, 0.1 to 8; Na.sub.2 O, 0.1 to 1; K.sub.2 O, 0.1 to 0.5; H.sub.2 O, 3 to 12; and incorporates 85 to 99% by mass of a fraction with a particle size of below 80 .mu.m and 1 to 15% by mass of a fraction with a particle size of from 80 to 200 .mu.m. The cement can also contain one or more additives: calcium oxide or calcium hydroxide, calcium carbonate, calcium carboaluminate. The method according to the invention for preparing said cement comprises a heat-treatment of calcium hydroalumosilicate containing SiO.sub.2 in an amount of not more than 8% by mass at a temperature of from 250.degree. to 600.degree. C. The heat-treated product is disintegrated to produce 85 to 99% by mass of a fraction with a particle size of below 80 .mu.m and 1 to 15% of a fraction with a particle size of from 80 to 200 .mu.m. During the heat-treatment of the hydroalumosilicate at least one component can be added calcium oxide or calcium hydroxide, calcium carbonate, calcium carboaluminate. The cement is useful in foundry engineering for the manufacture of articles from ferrous and non-ferrous metals.

Cement for the manufacture of cores and moulds and method for preparing

An improved method for recovering aluminum values from alkaline aluminosilicate raw material by sintering a comminuted aqueous mixture of the alkaline aluminosilicate material, limestone and soda solution wherein the alumino-silicate material is first comminuted with the soda solution to form a mixture with a fraction of particles larger than 0.08 mm greater than 20 percent by weight, mixing limestone with the mixture and comminuting until the fraction of particles larger than 0.08 mm is between 2 and 15 percent by weight.

Method for the production of alumina

The starting aluminate-alkaline solutions are subjected to two-stage carbonization with stirring and the production of hydrate of aluminum oxide, a gallium-containing precipitate, and solutions containing caustic and bicarbonate alkali, thereafter the produced gallium-containing precipitate is mixed with a solution containing caustic alkali to achieve a content of gallium in the solution of 0.05 to 1 g/l, the precipitate thus formed is separated and the solution enriched with gallium is mixed with a solution containing bicarbonate alkali, the produced mixture is evaporated to separate compounds of alkali metals, and the evaporated solution is carbonized to produce a solution containing alkali metal salts, and a gallium concentrate from which gallium is produced by transforming it into alkaline solution and subsequently reducing electrochemically. The proposed method makes it possible to extract gallium at a comparatively low cost from solutions in the processing, for example, of nephelines containing it in amounts which do not exceed 0.02 to 0.03 g/l. Owing to the proposed method it has become possible in the processes of concentration of gallium to produce a number of valuable components such as alkali metal salts contained in the starting ore.

Method for extraction of gallium from aluminate-alkaline solutions in

A process for recovering gallium from alkali aluminate solutions which consists in that the starting alkali aluminate solution is neutralized to a concentration of the caustic alkali of from 0.1 to 10 g/l, whereafter the neutralized liquor is evaporated to a concentration of the caustic alkali therein of from 30 to 150 g/l. Then the evaporated solution is corrected to obtain the ratio between the alkali metal oxide and alumina of above 2.0. The corrected solution is treated with a liquid alloy of gallium containing an element possessing an oxidizing potential exceeding that of gallium to give a concentrate containing more than 90% of gallium by mass, wherafter gallium of a higher purity grade is recovered from the resulting concentrate by the electrochemical method. The process according to the present invention makes it possible to recover gallium from alkali solutions resulting from the treatment of nephelines with the production of a 90% gallium concentrate, wherefrom gallium of an increased purity is obtained at relatively low cost. Processing of the concentrate with the production of gallium is simple, it is not encountered with any additional expenses and requires no additional equipment. Another advantage of the process resides in a more comprehensive utilization of low-grade aluminum-containing ores.

Process for recovering gallium from alkali aluminate solutions resulting

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%.

Process for the production of alumina from the mineral component of

Growing community of inventors

Saint-Petersburg, Russia

Nikolai S Shmorgunenko