Dissolution system and method for gibbsite-type bauxite in parallel tubes plus retention tank

Abstract

Provided are a parallel row tube and remaining tank dissolving-out system and method for gibbsite bauxite. The dissolving-out system comprises a circulating mother liquor tank, a two-series parallel row tube heating device, a mixer, a heat preservation remaining tank, a flash evaporation device and a diluting device. The two-series parallel row tube heating device is formed by connecting 2-3 groups of row tube heating devices in parallel, and each set of row tube heating devices is formed by sequentially connecting a primary row tube preheater, a secondary row tube preheater, a condensate water row tube heater and a live steam row tube heater in series. The method comprises the process steps that circulating mother liquor is conveyed to a two-series parallel row tube heating system through a mother liquor feeding pump to be heated, and then the circulating mother liquor and desilicated ore pulp are evenly mixed in the mixer and then enter the heat preservation remaining tank to be dissolved out; dissolved-out slurry is fed into the flash evaporation device, and enters the diluting device after being subjected to flash evaporation. According to the system and method, the ore pulp treatment capacity can be greatly improved, energy can be saved, and production cost can be reduced.

Description

technical field

[0001] The invention belongs to the technical field of alumina production, and in particular relates to a dissolution system and method for gibbsite-type bauxite in parallel tubes plus a residence tank. Background technique

[0002] At present, more than 95% of alumina plants in China adopt the Bayer process. The core of the Bayer method production process is the dissolution process of bauxite slurry. The purpose of dissolution is to make bauxite and circulating mother liquor react at a certain temperature to generate sodium aluminate solution. The reaction formula is:

[0003] al 2 o 3 (1 / 3)H 2 O+2NaOH+aq→2NaAl(OH) 4 +aq

[0004] Due to the different chemical compositions of bauxite ores in various places, the required dissolution temperature varies greatly; for gibbsite, low-temperature and low-alkali dissolution methods are generally used; the main technical indicators for the dissolution of gibbsite-type bauxite are : Dissolution temperature is 135°...

Examples

Embodiment 1

[0043] The structure of the dissolution system of gibbsite-type bauxite with parallel tubes and retention tanks is as follows: figure 1 As shown, it includes a circulating mother liquor tank 1, a double-series parallel tube heating device, a mixer 7, a heat preservation tank 8, a flash device and a dilution device; the circulating mother liquor tank 1 is heated by a mother liquor feeding pump 2 and a double series of parallel tubes The device is connected, and the double-series parallel tube heating device is composed of 2 sets of tube heating devices connected in parallel. Each group of tube heating devices is composed of a first-level tube preheater 3, a second-level tube preheater 4, and condensate water tube heating. The device 5 and the new steam tube heater 6 are sequentially connected in series, and each tube preheater and tube heater are equipped with a medium inlet, a medium outlet, a material inlet and a material outlet; the circulating mother liquor tank 1 is fed thr...

Embodiment 2

[0063] The structure of the stripping system of the gibbsite type bauxite in parallel and the retention tank is the same as in embodiment 1;

[0064] The gibbsite-type bauxite stripping method of parallel tubes plus retention tanks of the present embodiment adopts the above-mentioned stripping system, and proceeds according to the following process steps:

[0065] (1) The circulating mother liquor in the circulating mother liquor tank is transported to the double-series parallel tube heating system through the mother liquor feeding pump. The mother liquor first enters the first-stage tube preheater of each group of tube heating devices, The medium inlet of the tube preheater is passed into the secondary steam to heat the circulating mother liquor, and the circulating mother liquor enters the second-stage tube preheater after being heated, and the secondary steam heating cycle is passed into the medium inlet of the second-stage tube preheater The mother liquor and the circulati...

Embodiment 3

[0078] The structure of the dissolution system of gibbsite-type bauxite in parallel tubes plus residence tanks is the same as that in Example 1, the difference being that the double-series parallel tube heating devices are composed of three sets of tube heating devices connected in parallel;

[0079] The gibbsite-type bauxite stripping method of parallel tubes plus retention tanks of the present embodiment adopts the above-mentioned stripping system, and proceeds according to the following process steps:

[0080] (1) The circulating mother liquor in the circulating mother liquor tank is transported to the double-series parallel tube heating system through the mother liquor feeding pump. The mother liquor first enters the first-stage tube preheater of each group of tube heating devices, The medium inlet of the tube preheater is passed into the secondary steam to heat the circulating mother liquor, and the circulating mother liquor enters the second-stage tube preheater after bei...

technical field

[0001] The invention belongs to the technical field of alumina production, and in particular relates to a dissolution system and method for gibbsite-type bauxite in parallel tubes plus a residence tank. Background technique

[0002] At present, more than 95% of alumina plants in China adopt the Bayer process. The core of the Bayer method production process is the dissolution process of bauxite slurry. The purpose of dissolution is to make bauxite and circulating mother liquor react at a certain temperature to generate sodium aluminate solution. The reaction formula is:

[0003] al 2 o 3 (1 / 3)H 2 O+2NaOH+aq→2NaAl(OH) 4 +aq

[0004] Due to the different chemical compositions of bauxite ores in various places, the required dissolution temperature varies greatly; for gibbsite, low-temperature and low-alkali dissolution methods are generally used; the main technical indicators for the dissolution of gibbsite-type bauxite are : Dissolution temperature is 135°...

Examples

Embodiment 1

[0043] The structure of the dissolution system of gibbsite-type bauxite with parallel tubes and retention tanks is as follows: figure 1 As shown, it includes a circulating mother liquor tank 1, a double-series parallel tube heating device, a mixer 7, a heat preservation tank 8, a flash device and a dilution device; the circulating mother liquor tank 1 is heated by a mother liquor feeding pump 2 and a double series of parallel tubes The device is connected, and the double-series parallel tube heating device is composed of 2 sets of tube heating devices connected in parallel. Each group of tube heating devices is composed of a first-level tube preheater 3, a second-level tube preheater 4, and condensate water tube heating. The device 5 and the new steam tube heater 6 are sequentially connected in series, and each tube preheater and tube heater are equipped with a medium inlet, a medium outlet, a material inlet and a material outlet; the circulating mother liquor tank 1 is fed thr...

Embodiment 2

[0063] The structure of the stripping system of the gibbsite type bauxite in parallel and the retention tank is the same as in embodiment 1;

[0064] The gibbsite-type bauxite stripping method of parallel tubes plus retention tanks of the present embodiment adopts the above-mentioned stripping system, and proceeds according to the following process steps:

[0065] (1) The circulating mother liquor in the circulating mother liquor tank is transported to the double-series parallel tube heating system through the mother liquor feeding pump. The mother liquor first enters the first-stage tube preheater of each group of tube heating devices, The medium inlet of the tube preheater is passed into the secondary steam to heat the circulating mother liquor, and the circulating mother liquor enters the second-stage tube preheater after being heated, and the secondary steam heating cycle is passed into the medium inlet of the second-stage tube preheater The mother liquor and the circulati...

Embodiment 3

[0078] The structure of the dissolution system of gibbsite-type bauxite in parallel tubes plus residence tanks is the same as that in Example 1, the difference being that the double-series parallel tube heating devices are composed of three sets of tube heating devices connected in parallel;

[0079] The gibbsite-type bauxite stripping method of parallel tubes plus retention tanks of the present embodiment adopts the above-mentioned stripping system, and proceeds according to the following process steps:

[0080] (1) The circulating mother liquor in the circulating mother liquor tank is transported to the double-series parallel tube heating system through the mother liquor feeding pump. The mother liquor first enters the first-stage tube preheater of each group of tube heating devices, The medium inlet of the tube preheater is passed into the secondary steam to heat the circulating mother liquor, and the circulating mother liquor enters the second-stage tube preheater after bei...

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