Method for producing alumina by sintering lime of sulfur-containing bauxite

Abstract

The invention relates to the technical field of aluminum oxide, and in particular relates to a method for producing aluminum oxide through sintering sulfur-containing monohydrallite and lime. According to the method, through properly adding a small amount of flue gas desulfurization slag and the lime into sulfur-containing monohydrallite for sintering, the aluminum oxide is produced, enabling aluminum element and sulphur element in a raw material to form a 4Cao.3Al2O3.SO3 phase, and by enabling silicon element to form a gamma-2CaO.SiO2 phase, and then adopting a low-temperature dissolution technology to perform aluminum oxide production, the deleterious effect of the sulphur element is reduced, the aluminum oxide dissolution performance of clinker is improved, and better market application value and social benefit are realized.

Description

technical field

[0001] The invention relates to the technical field of alumina production, in particular to a process for producing alumina by a lime sintering method containing sulfur in raw materials such as low-grade bauxite or limestone. Background technique

[0002] The rapid development of the alumina industry has caused a sharp decline in the grade of available bauxite resources, and the development of new available bauxite resources has become the focus of current research work. my country is rich in high-sulfur bauxite resources, with a sulfur content between 0.7% and 4%. The current proven reserves are 150 million tons, accounting for 11% of the total reserves of bauxite resources. Therefore, there is an urgent need for a sulfur-containing aluminum The comprehensive utilization method of soil ore.

[0003] At present, there are two kinds of alumina production technologies for industrial application. One is the Bayer alumina production process. The Bayer process has...

Examples

Embodiment 1

[0040] The mass percentage is: Al 2 o 3 55.5%, SiO 2 21.8%, Fe 2 o 3 7.5%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=1.0. The mass percentage of each element in limestone is: CaO 50.9%, MgO 1.2%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 42.2% , SO 3 49.2%, of which the amount of desulfurization slag added is 9.0% of the total mass of sulfur-containing bauxite and limestone.

[0041] After the raw materials are mixed evenly according to the proportion, they are kept at 1300 degrees Celsius for 15 minutes, and then naturally cooled in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 75°C, the time was 30 minutes, and the concentration of sodium carbonate so...

Embodiment 2

[0043] The mass percentage is: Al 2 o 3 36.3%, SiO 2 24.8%, Fe 2 o 3 12.4%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=0.8. The mass percentage of each element in limestone is: CaO 52.1%, MgO 1.0%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 43.3% , SO 3 45.2%, of which the amount of desulfurization slag added is 3.5% of the total mass of sulfur-containing bauxite and limestone.

[0044] After mixing the raw materials evenly according to the proportion, keep the temperature at 1250 degrees Celsius for 30 minutes, and then cool naturally in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 60°C, the time was 15 minutes, and the concentration of sodium carbonate...

Embodiment 3

[0046] The mass percentage is: Al 2 o 3 41.1%, SiO 2 11.0%, Fe 2 o 3 10.3%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=0.95. The mass percentage of each element in limestone is: CaO 54.6%, MgO 0.7%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 44.6% , SO 3 40.8%, of which the amount of desulfurization slag added is 6.8% of the total mass of sulfur-containing bauxite and limestone.

[0047] After the raw materials are mixed evenly according to the proportion, they are kept at 1150 degrees Celsius for 60 minutes, and then naturally cooled in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 70°C, the time was 20 minutes, and the concentration of sodium carbonate ...

technical field

[0001] The invention relates to the technical field of alumina production, in particular to a process for producing alumina by a lime sintering method containing sulfur in raw materials such as low-grade bauxite or limestone. Background technique

[0002] The rapid development of the alumina industry has caused a sharp decline in the grade of available bauxite resources, and the development of new available bauxite resources has become the focus of current research work. my country is rich in high-sulfur bauxite resources, with a sulfur content between 0.7% and 4%. The current proven reserves are 150 million tons, accounting for 11% of the total reserves of bauxite resources. Therefore, there is an urgent need for a sulfur-containing aluminum The comprehensive utilization method of soil ore.

[0003] At present, there are two kinds of alumina production technologies for industrial application. One is the Bayer alumina production process. The Bayer process has...

Examples

Embodiment 1

[0040] The mass percentage is: Al 2 o 3 55.5%, SiO 2 21.8%, Fe 2 o 3 7.5%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=1.0. The mass percentage of each element in limestone is: CaO 50.9%, MgO 1.2%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 42.2% , SO 3 49.2%, of which the amount of desulfurization slag added is 9.0% of the total mass of sulfur-containing bauxite and limestone.

[0041] After the raw materials are mixed evenly according to the proportion, they are kept at 1300 degrees Celsius for 15 minutes, and then naturally cooled in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 75°C, the time was 30 minutes, and the concentration of sodium carbonate so...

Embodiment 2

[0043] The mass percentage is: Al 2 o 3 36.3%, SiO 2 24.8%, Fe 2 o 3 12.4%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=0.8. The mass percentage of each element in limestone is: CaO 52.1%, MgO 1.0%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 43.3% , SO 3 45.2%, of which the amount of desulfurization slag added is 3.5% of the total mass of sulfur-containing bauxite and limestone.

[0044] After mixing the raw materials evenly according to the proportion, keep the temperature at 1250 degrees Celsius for 30 minutes, and then cool naturally in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 60°C, the time was 15 minutes, and the concentration of sodium carbonate...

Embodiment 3

[0046] The mass percentage is: Al 2 o 3 41.1%, SiO 2 11.0%, Fe 2 o 3 10.3%, the rest is impurities, and the sulfur-containing low-grade bauxite is crushed and ground to a particle size of less than 200 mesh, accounting for more than 85%. Add limestone and desulfurization slag according to the calcium ratio C / A=0.95. The mass percentage of each element in limestone is: CaO 54.6%, MgO 0.7%, and the rest are impurities; the mass percentage of each element in desulfurization slag is: CaO 44.6% , SO 3 40.8%, of which the amount of desulfurization slag added is 6.8% of the total mass of sulfur-containing bauxite and limestone.

[0047] After the raw materials are mixed evenly according to the proportion, they are kept at 1150 degrees Celsius for 60 minutes, and then naturally cooled in the furnace. The clinker obtained by sintering was subjected to alumina dissolution, the dissolution temperature was 70°C, the time was 20 minutes, and the concentration of sodium carbonate ...

Images