<abstract xmlns="http://www.w3.org/1999/xhtml">In this paper, research on the possibilities of sodium sulphate (Na2SO4) separation from other substances in the filter ash sample is presented. The research material contains six components that differ in chemical composition and density. The possibilities of Na2SO4 separation using dry and wet methods were studied. The dry method was based on separation with a centrifugal air classifier at four cut size limits. The wet method was based on the dissolution of water-soluble components, filtration of insoluble components, and drying the products. The sulphur content of the individual products was determined using both methods. The aim of the research was to determine which method is more suitable for separation of the material in a way that most of the material would contain as little sulphur as possible and the rest of the material would contain concentrated sulphur. The wet method proved to be more successful. The product with mass fraction 33.1% of the total mass, obtained from the aqueous solution, contained 8.39% sulphur after filtration and drying. The water-insoluble component, with mass fraction 66.9% of the total mass, contained 0.56% sulphur. The dry method with the centrifugal air classifier proved to be less successful in comparison with the wet method. The particles containing Na2SO4 are very similar in size and density to the other components of the material, so the separation to the desired extent was not achieved.</abstract>

In this paper, research on the possibilities of sodium sulphate (Na2SO4) separation from other substances in the filter ash sample is presented. The research material contains six components that differ in chemical composition and density. The possibilities of Na2SO4 separation using dry and wet methods were studied. The dry method was based on separation with a centrifugal air classifier at four cut size limits. The wet method was based on the dissolution of water-soluble components, filtration of insoluble components, and drying the products. The sulphur content of the individual products was determined using both methods. The aim of the research was to determine which method is more suitable for separation of the material in a way that most of the material would contain as little sulphur as possible and the rest of the material would contain concentrated sulphur. The wet method proved to be more successful. The product with mass fraction 33.1% of the total mass, obtained from the aqueous solution, contained 8.39% sulphur after filtration and drying. The water-insoluble component, with mass fraction 66.9% of the total mass, contained 0.56% sulphur. The dry method with the centrifugal air classifier proved to be less successful in comparison with the wet method. The particles containing Na2SO4 are very similar in size and density to the other components of the material, so the separation to the desired extent was not achieved.

Removal of Na2SO4 from a Filter Ash

Faculty of Natural Sciences and Engineering, Department of Geotechnology, Mining and Environment

Materials and Geoenvironment

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

In this paper, research on the possibilities of sodium sulphate (Na2SO4) separation from other substances in the filter ash sample is presented. The research...

Sample 5 (S5)	Mass (g)	Mass per cent (%)	Sulphur content (%)
Sample 5 (S5)	108.4	100.0	3.38
Insoluble material (5I)	72.5	66.9	0.56
Soluble material (5S)	35.9	33.1	8.39

Sample 2 (S2)	Mass (g)	Mass per cent (%)	Sulphur content (%)
Sample 2 (S2)	251.7	100.0	3.38
Fine fraction (2F)	128.9	51.2	3.30
Coarse fraction (2C)	122.8	48.8	3.44

Sample 3 (S3)	Mass (g)	Mass per cent (%)	Sulphur content (%)
Sample 3 (S3)	260.2	100.0	3.38
Fine fraction (3F)	195.4	75.1	3.71
Coarse fraction (3C)	64.8	24.9	2.32

Sample 1 (S1)	Mass (g)	Mass per cent (%)	Sulphur content (%)
Sample 1 (S1)	258.4	100.0	3.38
Fine fraction (1F)	56.3	21.8	0.55
Coarse fraction (1C)	202.1	78.2	4.19

Test no.	Density (kg/m³)
1	2,445.8
2	2,579.5
3	2,539.5

Removal of Na₂SO₄ from a Filter Ash

Article Category: Original scientific paper

Published Online: Jun 04, 2020

Page range: 215 - 221

Received: Jan 27, 2020

Accepted: Jan 29, 2020

DOI: https://doi.org/10.2478/rmzmag-2019-0020

Keywords
sulphur, centrifugal air classifier, filtration, filter ash, waste material

© 2019 Blaž Janc et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Figure 1

Figure 2

Figure 3

Figure 4

Results of an attempt to remove sulphur from filter ash by the wet procedure

Classification at a cut size of 20 μm

Classification at a cut size of 30 μm

Classification at a cut size of 10 μm

Density measurements with a pycnometer

Classification at a cut size of 40 μm

Determination of operating conditions for the centrifugal air classifier using the operating diagram of the classifier

Sample 4 (S4)	Mass (g)	Mass per cent (%)	Sulphur content (%)
Sample 4 (S4)	254.0	100.0	3.38
Fine fraction (4F)	198.8	78.3	3.49
Coarse fraction (4C)	55.2	21.7	2.81

Cut size d_TV (mm)	RPM n (min⁻¹)	Airflow Q (m³/h)
10	8,900	46.1
20	5,200	49.8
30	4,100	50.9
40	3,500	51.5

Removal of Na2SO4 from a Filter Ash

Article Category: Original scientific paper

Published Online: Jun 04, 2020

Page range: 215 - 221

Received: Jan 27, 2020

Accepted: Jan 29, 2020

DOI: https://doi.org/10.2478/rmzmag-2019-0020

Keywordssulphur, centrifugal air classifier, filtration, filter ash, waste material

© 2019 Blaž Janc et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Figure 1

Figure 2

Figure 3

Figure 4

Results of an attempt to remove sulphur from filter ash by the wet procedure

Classification at a cut size of 20 μm

Classification at a cut size of 30 μm

Classification at a cut size of 10 μm

Density measurements with a pycnometer

Classification at a cut size of 40 μm

Determination of operating conditions for the centrifugal air classifier using the operating diagram of the classifier

Removal of Na₂SO₄ from a Filter Ash

Keywords
sulphur, centrifugal air classifier, filtration, filter ash, waste material