RU2327641C2 - Device for aluminate solutions decomposition - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention refers to hydrometallurgy equipment and can be implemented for extraction of aluminium hydroxide out of aluminate solutions during alumina production. The device for decomposition of aluminate solutions includes a cylinder case with a bottom and cover, a mixing unit, assembled along the axis of the case and equipped with a drive located on the cover, fittings for suspension supply and picking, vertical partitions arranged radially and secured by means of brackets on the inside surface of the case. On the vertical partitions there are attached air supplying vertical pipes into the upper portions of which horizontal fittings are cut in with the axes of the said fittings directed to the rotation side of the mixing unit, at that lower ends of vertical pipes are located lower than lower ends of the vertical partitions.

EFFECT: allows reduction of energy consumption at suspension mixing and at the same time facilitates uniform distribution of solid phase in a volume and along the height of the device.

2 dwg

Description

The invention relates to equipment for hydrometallurgical production and can be used for the separation of aluminum hydroxide from aluminate solutions in the process of obtaining alumina.

A known apparatus for the decomposition of aluminate solutions, consisting of a cylindrical body with a flat bottom and a lid, the suspension is mixed in which a chain mixer is installed along the axis of the housing. The drive of the mixing device is placed on the lid of the apparatus (A.I. Liner, N.I. Eremin and others. Production of alumina. M: Metallurgy, 1978, p.143). The disadvantages of this apparatus include high specific power consumption for mixing, exceeding ~ 20 W / m ^{3 of the} mixed suspension. In addition, in apparatuses with the indicated mixers, there is a separation of the solid phase of the suspension in height, which degrades the technological parameters of the process of decomposition of aluminate solutions.

Also known apparatus for the decomposition of aluminate solutions, consisting of a cylindrical body with a conical bottom. Mixing the suspension of aluminum hydroxide in it is carried out by an airlift installed along the axis of the body (Handbook of non-ferrous metals. Production of alumina. M .: Metallurgy, 1970, p. 261).

The disadvantage of this apparatus is not only the high specific energy costs of mixing (≥20 W / m ³ ), but also the rapid overgrowth of aluminum hydroxide deposits on the inner surface of the body, due to the low relative speed of the stirred suspension. All this leads to the loss of the target product and high operational costs for periodic dry cleaning of the apparatus.

The closest to the invention in technical essence and the achieved effect to the claimed solution is a decomposer according to the application of Germany No. 3239427 of 10.25.1982, the applicant Intersepara Holding A.S. (Switzerland). The apparatus consists of a cylindrical body with a bottom and a cover. A multi-tier mixer is installed along the apparatus axis, the drive of which is located on the cover of the decomposer.

Vertical partitions are radially fixed on the inner surface of the decomposer casing. The purpose of the latter is to enhance the axial current of the suspension in order to improve the homogenization conditions of the stirred medium. The decomposer is also equipped with nozzles for supplying and discharging the stirred suspension.

The disadvantages of this design include the increased specific energy costs for mixing and homogenizing the suspension in the volume of the apparatus, since the stirrer itself creates radial currents of the suspension, although the presence of vertical partitions enhances axial currents, it is insufficient for uniform distribution of the solid phase of the suspension along the height of the apparatus. To improve the performance of the distribution of the solid phase, it is necessary to increase the number of revolutions of the mixing device, which leads to a sharp increase in energy costs, since the power (N) consumed by the mixer depends on the number of revolutions.

The objective of the invention is to reduce the energy costs of mixing the suspension while ensuring uniform distribution of the solid phase in the volume and height of the apparatus.

The technical result consists in reducing energy costs for the homogenization of the suspension by 15-20%.

The technical result is achieved by the fact that in the apparatus for the decomposition of aluminate solutions, including a cylindrical body with a bottom and a cover, a mixing device mounted along the axis of the body with a drive located on the cover, nozzles for feeding the suspension and its selection, vertical partitions mounted radially and fixed brackets on the inner surface of the casing, on vertical partitions fixed vertical pipes for air supply, into the upper part of which horizontal pipes are cut, cat axes ryh directed in the direction of rotation of the stirring device, wherein the lower end of the vertical pipe placed below the lower end of the vertical partitions.

Figure 1 shows a diagram of the apparatus.

Figure 2 is a cross section of the apparatus.

The apparatus consists of a cylindrical housing - 1, bottom 2 and cover - 3. A mixing device - 4 is installed along the axis of the housing - 1, connected at the top with a coupling - 5 with a drive - 6. In the lower part, the shaft - 7 of the mixing device - 4 is fixed with a thrust bearing - 8. On the inner surface of the housing - 1, with the help of brackets - 9, vertical partitions - 10 are radially fixed. Vertical pipes - 11 are fastened to the vertical partitions - 10, into which air is supplied through the pipeline - 12. The lower end of the vertical pipes - 11 is located below the lower end of the partitions - 10, and the upper one is at the level of the upper end of the specified partitions. A horizontal branch pipe 13 is cut into the upper part of each of the vertical pipes - 11, the axis of which is directed towards the rotation of the mixing device - 4. The suspension enters the apparatus through the branch pipe - 14, and is removed from the apparatus through the branch pipe - 15.

The device operates as follows.

The suspension to be processed is fed into the apparatus through the nozzle - 15. It is mixed by the blades of a multi-tier mixing device - 4, which create a predominantly radial current of the mixed medium. Vertical partitions - 11 contribute to some extent to a change in the direction of flow to axial.

After filling the apparatus approximately 1/2 of its height, through a horizontal nozzle - 13, air is supplied into vertical pipes - 12, mounted on the partitions - 11. The gas-liquid mixture formed in the pipes - 12 rises up and flows through the nozzles - 14 into the apparatus volume . Thus, an additional axial circulation of the suspension occurs, which ensures complete homogenization of the stirred suspension and the same concentration of the solid phase in the entire volume of the apparatus.

Claims (1)

An apparatus for decomposition of aluminate solutions, including a cylindrical body with a bottom and a cover, a mixing device mounted along the axis of the body with a drive located on the cover, nozzles for feeding the suspension and its selection, vertical partitions mounted radially and fixed by brackets on the inner surface of the body, characterized the fact that vertical pipes are fixed on the vertical partitions for air supply, into the upper part of which horizontal pipes are cut, the axes of which are directed to the sides rotation of the agitator, the lower end of the vertical pipe placed below the lower end of the vertical partitions.

Images