Composition and process for pelletizing carbon-based materials for proppant and industrial applications
A method for producing an electrically-conductive pellet includes reducing a size of a first material. The method also includes wetting the first material to produce a first slurry. The method also includes introducing the first slurry into a fluidizer to produce a first pellet. The method also includes reducing a size of a second material. The second material is an electrically-conductive material. The method also includes wetting the second material to produce a second slurry. The method also includes applying the second slurry to the first pellet.
1 . A method for producing a pellet, comprising:
reducing a size of a material, wherein the material includes a blend of a clay and a coke such that the clay forms a composite network of electrically conductive domains and ceramic domains when solidified, wherein the blend has a weight ratio of coke to clay from about 1:25 to about 5:1, wherein the clay includes one or more of kaolin, bauxite, and alumina;
wetting the material with water and alginate to produce a slurry; and
flowing the slurry through a nozzle to produce a droplet of the slurry, the droplet falling into a solution to solidify the slurry into a pellet, wherein the pellet has an electrical conductivity of about 100 S/m to about 4000 S/m.
2 . The method of claim 1 , wherein the material is selected from the group consisting of coke, metal, graphite, and combinations thereof.
3 . The method of claim 1 , further comprising heating the pellet to a temperature of about 1,200° C. to about 1,450° C. to provide a sintered pellet.
4 . A method for producing an electrically-conductive pellet, comprising:
reducing a size of a first material, wherein the first material is alumina, silica, kaolin ore, or bauxite ore or combinations thereof;
wetting the first material to produce a first slurry;
introducing the first slurry into a fluidizer to produce a first pellet;
reducing a size of a second material, wherein the second material comprises an electrically-conductive material, wherein the second material includes a blend of a clay and a petroleum coke such that the clay forms a composite network of electrically conductive domains and ceramic domains when solidified, wherein the blend has a weight ratio of coke to clay from about 1:25 to about 5:1;
wetting the second material to produce a second slurry;
applying the second slurry to the first pellet to provide an electrically conductive pellet, wherein the pellet has an electrical conductivity of about 100 S/m to about 3000 S/m; and
calcining the electrically-conductive pellet to provide a calcined electrically-conductive pellet comprising a core that is a calcined first material and a shell comprising calcined electrically-conductive material.
5 . The method of claim 4 , wherein the electrically conductive material is selected from the group consisting of metal, graphite, and combinations thereof.
6 . The method of claim 4 , wherein an average cross-sectional length of the calcined electrically-conductive pellet is about 200 μm to about 4000.
7 . The method of claim 4 , wherein a bulk density of the calcined electrically-conductive pellet is about 0.3 g/cm3 to about 2.0 g/cm3.
8 . The method of claim 4 , further comprising:
reducing a size of a third material, wherein the third material comprises a combination of the first material and the second material; and
wetting the third material to produce a third slurry.
9 . The method of claim 8 , further comprising applying the third material to the first pellet before the second slurry is applied such that the third material is positioned at least partially between the first pellet and the second material.
10 . The method of claim 4 , further comprising:
reducing a size of a third material, wherein the third material comprises a combination of the first material and the second material;
wetting the third material to produce a third slurry;
applying the third material to the first pellet before the second slurry is applied such that the third material is positioned at least partially between the first pellet and the second material; and
calcining the electrically-conductive pellet after the second and third materials have been applied to the first pellet.
11 . The method of claim 10 , wherein:
an average cross-sectional length of the calcined electrically-conductive pellet is about 300 μm to about 2000 μm,
a bulk density of the calcined electrically-conductive pellet is about 0.5 g/cm3 to about 1.6 g/cm3, and
an electrical conductivity of the calcined electrically-conductive pellet is about 500 S/m to about 2000 S/m.
12 . The method of claim 10 , wherein an average cross-sectional length of the calcined electrically-conductive pellet is from about 300 μm to about 2000 μm.
13 . The method of claim 10 , wherein a bulk density of the calcined electrically-conductive pellet is about 0.5 g/cm3 to about 1.6 g/cm3.
14 . The method of claim 10 , wherein an electrical conductivity of the electrically-conductive pellet is about 500 S/m to about 2000 S/m.
15 . The method of claim 4 , wherein calcining is performed at a temperature of about 1,200° C. to about 1,450° C. to provide a sintered pellet.