SU430060A1 - METHOD OF INFORMATION ABILITY OF ALUMINATNB1 CRASH - Google Patents

Description

 one

This invention relates to alumina technology.

It is known that the processing of high-siliceous bauxites according to the sintering method requires a deep desilication to obtain high-grade alumina, which is carried out in two stages.

There is a known method of carrying out the first stage of the process at atmospheric pressure in open agitators in the presence of sodium hydroaluminosilicate seed about 100 g / l with a process time of 6-8 hours.

However, by a known method, the process is long and requires the introduction of large quantities of seed.

The purpose of the invention is to develop an efficient method of desilicating aluminate solutions, which will allow, at atmospheric pressure, to achieve a silicon modulus value of more than 200 with a shorter process time and a smaller seed.

For this, it is proposed to despreading when exposed to ultrasound with an oscillation frequency of at least 16 kHz and an intensity that creates cavitation, for 12-15 minutes and take a seed in an amount of 20-30 g / l.

Example. The process is carried out in open agitators on synthetic aluminate solutions at a concentration of 100 g / l acoustic 1.5-1.55, SiOs 3-3.1 g / l. The initial solution is mixed with a certain amount of sodium hydroaluminosilicate (GASN) at a rate of 20-30 g / l. The pulp thus prepared is exposed to ultrasound, which is carried out by directly introducing the waveguide into the glass. Within 15 minutes in the pulp, oscillations are created with a frequency of 16 KHz and an intensity of 0.8 W / cm2, sufficient to create cavitation in the volume being processed. Then within 2 hours the process of desquamation continues under normal conditions.

The results of the experiments in the presence of 25 g / l of sodium hydroaluminosilicate are shown in Table 1.

Due to the fact that the duration of the process is reduced by about 3 times, the consumption of steam, electricity, labor, etc., is reduced accordingly. In addition, the increase in the amount of seed by 3-4 times leads to a decrease in specific cargo flows and facilitates the separation and washing sludge Thus, the use of the proposed method of desilination gives

opportunity to reduce the cost of alumina. The interrelation of the effect of ultrasound and priming in its specific dosage, leading to an intensification of the process of desiliconization of aluminate solutions, is given in

tab. 2

Table 1

From the table it can be seen that the acceptable degree of desilication () is achieved with the addition of sodium hydroaluminosilicate in the amount of 25 g / l. A further increase in the amount of seed, although it leads to a slight increase in the degree of desilification, but at the same time significantly increases the loss of alumina and alkali due to the deterioration of the laundering of the sludge.

Such an o6pa30iM, under the condition of exposure to ultrasound, the optimum consumption of the GASN seed is in the desalination of 20-30 g / l.

table 2

Similarly, in the case of using nepheline concentrate.

Subject invention

A process for the desilination of aluminate solutions at atmospheric pressure in the presence of a soda hydroaluminosilicate seed, characterized in that, in order to intensify the process, desilication is carried out

exposure to ultrasound with an oscillation frequency of at least 16 kHz and an intensity that creates cavitation for 12–15 min and the seed is taken in an amount of 20–30 g / l.