JPS5827211B2 - Red mud separator in alumina production - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an agent used to separate red mud consisting of alkali-insoluble impurities produced when aluminum-containing minerals are treated with alkali to extract aluminum.

Conventionally, starch or sodium polyacrylate has been used as a settling aid for separating such red mud as a precipitate.

However, although starch is excellent in clarifying aluminate extracts containing red mud, it is inferior in its effect of promoting sedimentation of red mud, and sodium polyacrylate is effective in promoting sedimentation of red mud, but it has a poor effect on aluminate extraction. Liquid clarification is poor.

When a cationic flocculant is used as a sedimentation aid for red mud, the clarity of the aluminate extract is generally improved, but there is a problem with the settling speed of the red mud, and furthermore, since it is added to a highly concentrated alkaline solution, The amine-type cationic flocculants cannot exhibit cationic properties.

For this reason, conventionally, in order to use a quaternary cationic flocculant as a red mud separating agent, sodium polyacrylate had to be used in combination to increase the escape rate.

Since the former is cationic and the latter is anionic, they cannot be used in combination, and the operations are complicated, so improvements have been sought.

This invention provides a new red mud separating agent for alumina production based on the above findings, and has the following formula: R: H or CH3 X: negative atom or group A: having 1 to 3 carbon atoms Alkylene group R1: Alkyl group having 1 to 3 carbon atoms R2: Alkyl group having 1 to 3 carbon atoms R3: Benzyl group, alkyl group having 1 to 4 carbon atoms, β-hydroxyethyl group, β-hydroxypropyl group, or α-hydroxy It is represented by a propyl group and has an intrinsic viscosity of 6 [d4/g,) or more, 3
The component is a water-soluble polymer electrolyte having 0°C [η)IN-NaN03.

Examples of the polymer electrolyte represented by the above formula include a polymer of β-acryloyloxyethyltrimethylammonium chloride, a polymer of β-acryloyloxyethyldimethylbenzylammonium chloride, etc. However, any polymer electrolyte represented by the above formula may be used. For example, other polymers may be used.

For example, X is OH, CI, Br, and A is (CH2)2. (CH2)3. Examples of R1°R2 include methyl, ethyl, and propyl groups, such as CH2CH (CH3).

The water-soluble polymer electrolyte represented by the above formula has much better clarity for aluminate extracts containing red mud than conventional polymer flocculants, and has a particularly high intrinsic viscosity of 30°G [η) I NN a The above-mentioned polymer electrolyte having NOs of 6 [44,799 or more] can rapidly improve the sedimentation rate of red mud.

The present inventor focused on the excellent clarity of certain cationic polymer electrolytes used as separation agents for red mud, and further worked to improve the clarity and sedimentation rate. We found that viscosity is an important factor for improvement.

As shown in the examples below, its intrinsic viscosity [η] 30°C
In the range where lNNaNO3 is up to 6 (dl, Q), the influence of the intrinsic viscosity increaser on the sedimentation rate of red mud is not so large, and even if it is, it is about the same as that of the conventionally used sodium polyacrylate. be.

When the above-mentioned intrinsic viscosity becomes 6 [d4/g]4/, the influence on the sedimentation rate tends to become particularly significant as the intrinsic viscosity increases, and the clarity of the aluminate extract is also significantly improved.

To use this red mud separating agent, prepare a 0.1 to 1% aqueous solution of the above-mentioned polymer electrolyte, and add this to an extract containing red mud obtained by treating raw aluminum ore with an alkaline solution. I see it.

The amount of calories added to the extract containing red mud is 11) 1111 or more, preferably 5 to 20 pp [Il].

According to the red mud separating agent of the present invention, the clarity of the extract is excellent and the separation speed of the red mud is fast, so high-grade alumina can be obtained, and a large amount of the extract can be processed with a small device. be able to.

Example l Na2O1209/11, A120353 V!
! 129 g of dried gibbsite type bauxite was added to the sodium aluminate solution 11 and dissolved in an autoclave at 150°C for 30 minutes.

Thereafter, the temperature was lowered to 96°C, the mixture was placed in a 100 m4 colorimetric tube, a predetermined amount of a precipitant was added thereto, and the mixture was stirred to precipitate the red mud.

The results are as shown in the drawing, and as is clear from the drawing, the electrolyte of the present invention has much better clarity than sodium polyacrylate, and has an intrinsic viscosity of 6 [4479
At 9 or higher, the sedimentation rate is rapidly improved.

Example 2 The following results were obtained by carrying out the same procedure as in Example 1 except that the amount of calories added to each precipitant was changed.

[Brief explanation of the drawing]

The figure is a curve diagram showing the relationship between the intrinsic viscosity of a sedimentation agent, the sedimentation rate of red mud, and the clarity of an aluminate extract containing red mud.

Claims (1)

[Claims] 1 Formula where R: H or CH3 X: Negative atom or group A: Alkylene group having 1 to 3 carbon atoms R1: Alkyl group having 1 to 3 carbon atoms R2: Alkyl group having 1 to 3 carbon atoms R3: is represented by a benzyl group, an alkyl group having 1 to 4 carbon atoms, a β-hydroxyethyl group, a β-hydroxypropyl group, or an α-hydroxypropyl group, and has an intrinsic viscosity of 6 (dA/1 or more) at 30°C [η ) A red mud separating agent in alumina production containing a water-soluble polymer electrolyte with IN NaNO3 as a component.