Table 1.
Elemental composition of the coal gangue sample.
Fig 1.
Characteristics of the occurrence of Ca and Mg.
Table 2.
Grain size distribution and calcium–magnesium content of crushed coal gangue.
Table 3.
Density composition and calcium-magnesium content of crushed coal gangue.
Table 4.
Main structural parameters of the conventional cyclone and bottom-impact cyclone.
Fig 2.
Structural schematic diagram of conventional cyclone and bottom-impact cyclone.
Fig 3.
Characteristic structural diagram of bottom-impact cyclone.
Fig 4.
Grid independence verification.
Fig 5.
Theoretical and actual diagrams of the cyclone separation enrichment system for calcium and magnesium components.
(a) Theoretical diagram; (b) Actual diagram.
Fig 6.
Pressure distribution of the conventional hydrocyclone under different feed velocities.
Fig 7.
Tangential velocity distribution of the conventional hydrocyclone under different feed velocities.
Fig 8.
Axial velocity distribution of the conventional hydrocyclone under different feed velocities.
Fig 9.
Air column cloud map under different inlet velocities in the conventional hydrocyclone.
Fig 10.
Pressure distribution of bottom-impact hydrocyclone at different impact pipe heights.
Fig 11.
Pressure distribution at X = 0 and different sectional heights under different impact pipe heights in the bottom-impact hydrocyclone.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, and (f) Z = −246 mm.
Fig 12.
Tangential velocity distribution of the bottom-impact hydrocyclone at different impact pipe heights.
Fig 13.
Tangential velocity distribution at X = 0 and different sectional heights under different impact heights in the bottom-impact hydrocyclone.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, (f) Z = −246 mm.
Fig 14.
Axial velocity distribution of the bottom-impact hydrocyclone under different impact pipe heights.
Fig 15.
Axial velocity profiles of the bottom-impact hydrocyclone at X = 0 and different section heights.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, (f) Z = −246 mm.
Fig 16.
The air column in the bottom-impact cyclone under different impact pipe heights.
Fig 17.
Pressure distribution of the bottom-impact cyclone under different impact velocities.
Fig 18.
Pressure distribution diagrams at the X = 0 plane and different height sections under various impact velocities in the bottom-impact cyclone.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, and (f) Z = −246 mm.
Fig 19.
Tangential velocity distribution under different impact velocities in the bottom-impact hydrocyclone.
Fig 20.
Pressure distribution diagrams at the X = 0 plane and different height sections under various impact velocities in the bottom-impact cyclone.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, (f) Z = −246 mm.
Fig 21.
Axial velocity distribution under different impact velocities in the bottom-impact hydrocyclone.
Fig 22.
Axial velocity distribution at the X = 0 plane and different sectional heights under different impact velocities in the bottom-impact hydrocyclone.
(a) Z = −85 mm, (b) Z = −166 mm, (c) Z = −186 mm, (d) Z = −206 mm, (e) Z = −226 mm, (f) Z = −246 mm.
Fig 23.
Air core cloud map of bottom-impact hydrocyclone at different impact velocities.
Fig 24.
Overflow coarse‐carry rate and underflow fine-carry rate of the conventional hydrocyclone at different feed velocities.
Fig 25.
Hancock’s overall classification efficiency of the conventional hydrocyclone at different feed velocities.
Fig 26.
Ash content under different feed velocities in the conventional hydrocyclone.
Fig 27.
Calcium and magnesium content under different feed velocities in the conventional hydrocyclone.
(a) Calcium content, (b) Magnesium content.
Fig 28.
Overflow coarse‐carry rate and underflow fine-carry rate of the bottom-impact hydrocyclone at different impact pipe heights.
Fig 29.
Hancock’s overall classification efficiency of the bottom-impact hydrocyclone at different impact pipe heights.
Fig 30.
Ash content of the bottom-impact hydrocyclone at different impact pipe heights.
Fig 31.
Calcium and magnesium content of the bottom-impact hydrocyclone at different impact pipe heights.
(a) Calcium content, (b) Magnesium content.
Fig 32.
The overflow coarse‐carry rate and underflow fine-carry rate of the bottom-impact hydrocyclone at different impact velocities.
Fig 33.
Hancock’s overall classification efficiency of the bottom-impact hydrocyclone at different impact velocities.
Fig 34.
Ash content at different impact velocities in a bottom-impact hydrocyclone.
Fig 35.
Calcium and magnesium content at different impact velocities in a bottom-impact hydrocyclone.
(a) Calcium content, (b) Magnesium content.