Use: in the production of aluminum hydroxide. The inventive aluminum hydroxide crushed steam at 120 to 250°C, profilebuy mixture condense and thicken to obtain a water suspension with a solids content of 50 to 300 g/l and sodium oxide in the liquid phase of 0.05 – 5 g/l Aqueous suspension is introduced into a supersaturated aluminate solution, subjecting the extract obtained suspension under stirring, separating the separated aluminum hydroxide from the mother liquor and washed. 1 C.p. f-crystals, 1 Il., table 1.

The invention relates to the production of aluminum hydroxide, and specifically to the production of fine aluminum hydroxide from aqueous solutions of sodium aluminate.

A method of obtaining fine aluminum hydroxide [1] in which the process is conducted in two stages. In the first stage aluminate solution is neutralized with hydrochloric acid, and the resulting aluminum hydroxide is used as the seed decomposition of supersaturated aluminate solution decomposition in the second stage. As a result, the aluminum hydroxide with the structure of hydrargillite, which is used for various purposes, for example for prigotovit a result of neutralization of caustic alkali aluminate solution. The resulting aluminum hydroxide is characterized by high dispersion and amorphous structure of the particles, suggesting its high seed activity in the decomposition of the aluminate solutions.

However, this method of preparation of the seed is only possible when using specially prepared, not containing impurities aluminate solutions. Otherwise, the resulting aluminum hydroxide absorbs impurities from the solution and the seed activity is declining. In addition, with the implementation of this method because of the low settling velocities and filtering the seed aluminum hydroxide is served on the second stage in the form of a suspension. In this case, all formed in the first stage of salt fall on the second stage, polluting the primary product and circulating in the sphere of production solutions.

Closest to the invention to the technical essence and the achieved effect is a method of obtaining fine aluminum hydroxide as seed use aluminum hydroxide, ground to the specific surface area, more than or equal to 1 m²/g, while the seed is introduced into aluminate solution in an amount such that the total surface satco its chemical and therefore, the seed activity is low, which necessitates the use of considerable quantities of seed and high energy costs in its preparation.

The basis of the invention is to develop a method of preparation of the seed aluminum hydroxide, which ensures its high seed activity and chemical purity, which ultimately leads to reduced consumption of material and energy resources.

For this purpose, the method of producing aluminum hydroxide, comprising grinding the seed aluminum hydroxide, mixing the crushed seed with supersaturated solution and extract the resulting suspension with stirring, the seed aluminum hydroxide crushed steam at 120-250^aboutC. condense profilebuy mix with the receiving water suspension containing 50-300 kg/m³powdered aluminum hydroxide, which is used as seed.

Appropriate content of sodium oxide in the liquid phase of the suspension to maintain within 0.05 to 5 g/L.

Grinding aluminum hydroxide steam at 120-250^aboutProvides obtaining chemically pure aluminum hydroxide high seed activity. Research the number of cracks, chips and ledges, which have an amorphous structure.

The specified surface structure determines its high seed activity when using aluminum hydroxide as seed.

The maximum effect is achieved when the steam temperature in the grinding chamber 120-250^aboutC.

When the temperature drops below 120^aboutWith the chemical activity of the surface of the crushed aluminum hydroxide is the same as with other methods of grinding.

The temperature increases above 250^aboutWith practically does not increase the chemical activity of the surface, however, growing costs of thermal energy on the preparation of the seed.

When the solid content in the aqueous suspension obtained after condensation paraphilias mixture, 50-300 g/l seed activity suspension maximum.

The reduction in the content of solid in the suspension is below 50 g/l practically no effect on her bare activity, but in the process introduces a significant amount of water, which requires additional cost to its evaporation.

Increasing the concentration of solids in suspension in water above 300 g/l of her bare activity is declining. This is caused by a decrease in x is an acid-base type.

The content of sodium oxide in the liquid phase of the aqueous suspension in the range of 0.05-5 g/l provides its maximum seed activity.

The lower limit of concentration is limited by the content of intracrystalline alkali-washed aluminum hydroxide, coming to grinding.

When the concentration of sodium oxide above 5 g/l seed activity suspension is reduced due to the dissolution of the amorphous structures of the surface of the seed.

The proposed method of producing aluminum hydroxide is performed with the use of manufactured and used at domestic plants equipment: jet mill type ES-06; SP-1, etc.

In the jet mill grinding occurs without the use of grinding media used the principle of smokable material at the collision of particles. Using jet mills is required to ensure the proposed parameters of the process and obtain the required technical result.

In boroncontaining provide cooling peoplewho flow. Cooling of the produced water. When this vapor condenses and forms a suspension of aluminum hydroxide in water, which after condensation is used in Kea.

The aluminum hydroxide from the hopper 1 by a screw 2 is fed to the accelerating tube jet mill 3. Accelerating tubes aluminum hydroxide accelerates vapor pressure. Particles colliding beams collide, crushed and taken out steam in a centrifugal separator 4. Large particles are returned to the mill on Dorisol, and crushed to the desired particle size will be stored in the dust collection system 5. Paraphilias stream is cooled, condensed, aqueous suspension 6 is condensed in the thickener 7, is mixed with supersaturated aluminate solution 8 and enters the reactor 9, which is maintained under stirring. After soaking the aluminum hydroxide is separated from the mother liquor in the filter 10, washed and sent to the consumer.

Comparing data from multiple experiments suggests that the grinding of aluminum hydroxide in the jet mill steam at 120-250^aboutWith and subsequent use of the aqueous suspension of powdered material containing 50-300 g/l solid as a seed, improves the efficiency of the process and the quality of the finished product due to the production of chemically pure seed, high seed activity.

Industrial Prime p 1 kg of aluminum hydroxide with an average crystal size of 40 μm pulverized steam in a laboratory jet mill. The temperature of the steam at the entrance to the jet mill was 160^aboutWith the pressure of 7 MPa. The temperature in the grinding chamber 140^aboutC. the Average size of the crystals after grinding to 2.0 μm.

Powdered aluminum hydroxide, made in the form paraphilias mixture, catch in boroncontaining film type. The condensation of the steam produced by the cold water in boroncontaining. After condensation peoplewho flow received 10 l of a suspension containing 100 g/l of powdered aluminum hydroxide and 0.4 g/l of sodium oxide in the liquid phase.

0,04 l aqueous suspension is mixed with 1 liter of aluminate solution containing, g/l: Na₂O_ku130,9; Al₂O₃137,2; Na₂CO₃20,3; NaCl 12,2; Na₂SO₄5,4; organic carbon (Corg.) 12,4. The resulting suspension is placed in a reactor and maintained under stirring at 55^aboutC for 24 h

The degree of decomposition of the aluminate solution was 50.2% of the amount of production of aluminum hydroxide 109,4, the Average size of the crystals in the sediment of 3.6 μm, the content of impurities in the aluminum hydroxide, Na₂O 0,42; Fe₂O₃0,021; SiO₂0,018.

The results of the experiments within the proposed regimes, optimal and beyond C the efficiency of the decomposition is achieved at a temperature in the grinding chamber 120-250^aboutWith, the content of the crushed aluminum hydroxide in water suspension 50-300 g/l and the content of sodium oxide in the liquid phase of the aqueous suspension of 0.05-5 g/L.

1. The METHOD of producing ALUMINUM HYDROXIDE, comprising grinding the seed aluminum hydroxide, mixing the crushed seed aluminum hydroxide from a supersaturated aluminate solution, aging the resulting suspension with stirring, the Department released the aluminum hydroxide from the mother liquor and washing, characterized in that the grinding of aluminum hydroxide carried out with steam at 120 250^oWith the obtained profilebuy suspension condense and thicken to obtain a water suspension with a solids content of 50 to 300 g/l and it is introduced into the supersaturated solution.

2. The method according to p. 1, characterized in that the content of sodium oxide in the liquid phase of the aqueous suspension is maintained within the range of 0.05 to 5.0 g/L.