Aging method for preparing pseudo-boehmite by carbonation method

Abstract

The invention discloses an aging method of pseudo-boehmite prepared by a carbonation method. The method concretely comprises the steps of enabling the pseudo-boehmite prepared by the carbonation method to form gel, and then rapidly carrying out on solid-liquid separation; after that, putting a filter cake attached with mother liquor into a closed container, heating and aging. The aging method is simple in technology, low in energy consumption, high in productivity and low in production cost; the prepared pseudo-boehmite product is pure in crystalline phase, high in degree of crystallinity, good in gel dissolubility, less in impurity and wide in use.

Description

technical field

[0001] The invention relates to a preparation method of pseudo-boehmite, in particular to an aging method for preparing pseudo-boehmite by a carbonation method. Background technique

[0002] Pseudo-boehmite can be prepared in a variety of ways. Most of the domestic sintered alumina factories use carbonation to prepare pseudo-boehmite. Because it is grafted on the alumina production process, the source of raw materials is convenient, and the by-products in the process, The waste liquid can be returned to the alumina process to realize a closed loop, so the product cost is low and there is no environmental pollution. The technical process of preparing pseudo-boehmite by carbonation method includes batching, gelling, aging, washing, liquid-solid separation, drying and other steps in sequence.

[0003] There are many domestic and foreign patents and related reports on the aging technology in the process of preparing pseudo-boehmite by carbonation, but they are a...

Examples

Embodiment 1

[0014] A carbonation method for preparing pseudo-boehmite aging method provided in Example 1 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjusting its alumina content to 42g / l, The caustic ratio is 1.52, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 15 minutes, the pH value of the slurry is 13, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed plastic bag, put it in water at 70°C for 2 hours, add hot water at 80°C to melt the slurry, stir repeatedly, wash and remove impurities, and finally dry it in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

Embodiment 2

[0016] A carbonation method for preparing pseudo-boehmite aging method provided in Example 2 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjust its alumina content to 23g / l, The caustic ratio is 1.37, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 10.5 minutes, the pH value of the slurry is 10.5, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed plastic bag, put it in water at 90°C for 4 hours, add hot water at 75°C to melt the slurry, stir repeatedly, wash and remove impurities, and dry in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

Embodiment 3

[0018] A carbonation method for preparing pseudo-boehmite aging method provided in Example 3 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjusting its alumina content to 36g / l, The caustic ratio is 1.42, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 13 minutes, the pH value of the slurry is 11, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed flask, put it in water at 95°C and keep it warm for 3.5 hours, then add hot water at 95°C to melt the slurry, perform repeated stirring, washing and impurity removal, and dry in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

technical field

[0001] The invention relates to a preparation method of pseudo-boehmite, in particular to an aging method for preparing pseudo-boehmite by a carbonation method. Background technique

[0002] Pseudo-boehmite can be prepared in a variety of ways. Most of the domestic sintered alumina factories use carbonation to prepare pseudo-boehmite. Because it is grafted on the alumina production process, the source of raw materials is convenient, and the by-products in the process, The waste liquid can be returned to the alumina process to realize a closed loop, so the product cost is low and there is no environmental pollution. The technical process of preparing pseudo-boehmite by carbonation method includes batching, gelling, aging, washing, liquid-solid separation, drying and other steps in sequence.

[0003] There are many domestic and foreign patents and related reports on the aging technology in the process of preparing pseudo-boehmite by carbonation, but they are a...

Examples

Embodiment 1

[0014] A carbonation method for preparing pseudo-boehmite aging method provided in Example 1 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjusting its alumina content to 42g / l, The caustic ratio is 1.52, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 15 minutes, the pH value of the slurry is 13, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed plastic bag, put it in water at 70°C for 2 hours, add hot water at 80°C to melt the slurry, stir repeatedly, wash and remove impurities, and finally dry it in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

Embodiment 2

[0016] A carbonation method for preparing pseudo-boehmite aging method provided in Example 2 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjust its alumina content to 23g / l, The caustic ratio is 1.37, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 10.5 minutes, the pH value of the slurry is 10.5, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed plastic bag, put it in water at 90°C for 4 hours, add hot water at 75°C to melt the slurry, stir repeatedly, wash and remove impurities, and dry in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

Embodiment 3

[0018] A carbonation method for preparing pseudo-boehmite aging method provided in Example 3 of the present invention is specifically as follows: using sodium aluminate refined solution produced by soda lime sintering method as raw material, adjusting its alumina content to 36g / l, The caustic ratio is 1.42, and industrial carbon dioxide gas with a volume concentration of 30-40% is introduced. After 13 minutes, the pH value of the slurry is 11, and the obtained slurry is rapidly separated from liquid to solid. Put the separated filter cake into a sealed flask, put it in water at 95°C and keep it warm for 3.5 hours, then add hot water at 95°C to melt the slurry, perform repeated stirring, washing and impurity removal, and dry in an oven to obtain a qualified product. Please refer to Attached Table 1 for product indicators.

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