RU2017688C1 - Method of amorphous aluminosilicate filler making - Google Patents

Abstract

FIELD: inorganic chemistry. SUBSTANCE: aluminium salt containing cations Al³⁺ (aluminium sulfate) is added to the solution of sodium silicate. Before addition aluminium sulfate is mixed with ammonium nitrate solution (concentration is 40-60 g/l as NH₄NO₃) following by precipitation of aluminosilicate hydrogel at pH 9.4-9.7, filtration, drying and grinding. Method is used for production of amorphous aluminosilicates. EFFECT: improved method of production. 1 tbl

Description

 The invention relates to the production of amorphous aluminosilicates and can be used in the refining and chemical industries.

A known method of producing amorphous aluminosilicates, adopted as a prototype, according to which 60-424 parts by weight an aqueous solution of sodium silicate containing 10-24 wt.% SiO ₂ and having a module of 1.75-3.6, mixed and homogenized with added at the same time 5-98 wt.h. an aqueous solution of sodium aluminate containing 3-10 wt.% Al ₂ O ₃ and having an alkalinity modulus of 1.0-2.85. The resulting aluminosilicate hydrosol is immediately mixed and homogenized with 40.8-163 parts by weight an aqueous solution of aluminum nitrate containing 3-5 wt.% Al ₂ O ₃ .

Aluminum sulphate in an amount of 10-84.9 parts by weight can also be used as a source of aluminum cation. when the content of Al ₂ O ₃ 1,5-5,11 wt.%.

In the precipitated aluminosilicate hydrogel, a pH of 6.5-12.9 was maintained. The hydrogel is aged for 10 minutes to 48 hours at 293-343 K, the hydrogel being stirred and, after filtering the mother liquor, the hydrogel is washed with 40-570 parts by weight. demineralized water with a temperature of 293-313 K, crushed in a colloid mill, molded and dried at 393-573 K, and finally calcined at 623-873 K for 3 hours. An amorphous aluminosilicate with the chemical composition is obtained, mol: Na ₂ O 0 3-2.6; Al ₂ O ₃ 1; SiO ₂ 5.06-15.05; containing 3.8-10 wt.% water, having a specific surface area of 87 m ² and a mechanical strength of 92-97.5%. Yield 96.55-100%.

 The disadvantage of this method is to obtain a product with a high bulk density and a significant content of impurities, which leads to a decrease in the quality of amorphous aluminosilicate - a component of rubbers.

 The aim of the invention is to improve the quality of amorphous aluminosilicate filler by reducing the bulk density and the amount of impurities.

This goal is achieved by the fact that aluminum sulfate is used as aluminum salt, before introduction it is mixed with a solution of ammonium nitrate with a concentration of 40-60 g / l according to NH ₄ NO ₃ , and the precipitation is carried out at a pH of 9.4-9.7.

 The essence of the proposed method is as follows.

A solution of sodium silicate is prepared. Separately, a solution of aluminum sulfate is prepared, which, before being introduced into sodium silicate, is mixed with a solution of ammonium nitrate at a concentration of 40-60 g / l according to NH ₄ NO ₃ and a so-called precipitation mixture is obtained. Mix solutions of sodium silicate and precipitation mixture. The resulting hydrogel is homogenized, filtered, and the precipitate is washed with water. The washed precipitate is dried and ground.

PRI me R 1. Prepare a solution of sodium silicate with N at Na ₂ O = 1,67, separately prepare a precipitation mixture with a concentration of NHNO ₃ - 50 g / l, and the concentration of the solution of aluminum sulfate is 0.6 N in Al ₂ O ₃ . At 23 ^° C, 250 ml of Na silicate solution and 350 ml of precipitation mixture are mixed to a pH of 9.4. The resulting hydrogel was stirred for 10 minutes and then filtered on a vacuum funnel and washed with the condensate in an amount of 20: 1. After a three-hour wash was filtered and dried at 110-120 ^C to a residual moisture of 15.4%.

 The dried mass is ground in a porcelain mortar, sieved on a sieve of 0.16 and quality indicators are determined according to TU 38.102.67-84.

PRI me R 2. Prepare a solution of sodium silicate with N at Na ₂ O = 1,67. Separately, a precipitation mixture is prepared in which the concentration of NH ₄ NO ₃ is 40 g / l and the concentration of aluminum sulfate is 0.6 l of Al ₂ O ₃ .

Mix 250 ml of sodium silicate solution and 330 ml of coagulating the mixture at 22 ^{° C} and continuous stirring until pH 9.7.

The mixture was stirred for 10 min, then filtered and washed with the condensate in an amount of 20: 1. After a three-hour wash mixture is filtered on a vacuum filter and dried at ¹¹⁰ ° C to a residual moisture of 16.2%.

 The dried mass is ground in a mortar, sieved on a sieve of 0.16 and the quality of the filler is determined according to TU 38.10267-84.

PRI me R 3. Prepare a solution of sodium silicate with a concentration of 1.67 N. by Na ₂ O. Separately, a precipitation mixture with a concentration of NH ₄ NO _{3 of} 60 g / L is prepared, and the concentration of the aluminum sulfate solution is 0.6 n by Al ₂ O ₃ . Mix 250 ml of sodium silicate solution and 340 ml of coagulating the mixture at 26 ^{° C} and pH 9.5. Stirring lasts 10 minutes.

After three-hour wash was filtered, dried at ¹¹⁰ ° C to a residual moisture of 15.8%.

 The dried mass is triturated in a porcelain mortar and sieved on a sieve of 0.16.

 The quality of the filler is determined according to TU-38.10267-84.

 The table shows the quality indicators of amorphous aluminosilicate filler and rubbers prepared on its basis.

Claims (1)

METHOD FOR PRODUCING AN AMORPHIC ALUMINOSILICATE FILLER, which includes introducing an aluminum salt into the sodium silicate solution containing Al ³⁺ cations, subsequent precipitation of the resulting alumina-silica hydrogel, filtering, drying and grinding, characterized in that, in order to improve the quality of the filler by eliminating harmful substances from its composition , aluminum sulfate is used as aluminum salt, before its introduction it is mixed with a solution of ammonium nitrate with a concentration of 40-60 g / l according to NH ₄ NO ₃ , and precipitation is carried out at a pH of 9.4 - 9.7.

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