396
A. E. Artyukhov et al.
2. Retentivity – amount of diesel fuel distillate (in percentage terms from granule’s
total weight) which remains in the granule after its transportation and surplus
runoff
3. PAN granule firmness
Absorptivity is defined by the total volume of pores (their form and nature are not
taken into account; the decisive factor is their size) and by the developed nanoporous
surface structure, which mostly consists of macropores (size is over 50 nm).
The retentivity normative indicator is provided by the internal “modification”
nanoporous structure. This structure includes mainly wavy mesopores (size 2–
50 nm). Firmness of the granule is defined by the core destruction degree (or
integrality). Low firmness of the granule has a negative impact on the production
ecological indicators (great deal of dust) and leads to the granules sealing. Thus,
a nanoporous structure must be developed on the granule surface and in its nearsurface layers.
Results of previous studies [11, 12] have shown that modification of ammonium
nitrate granules by humidification and subsequent heat treatment leads to changes
in the parameters of crystal lattice of samples. The porous surface of granules in this
case consists primarily of macropores, the presence of which allows to open access
to internal mesopores (which were also formed during the modification process).
The main objective of the work is to study the impact of humidifier type and
the number of humidification cycles on the surface and internal structure of PAN
granule nanopores and its quality indicators (holding and absorption capacity).
25.2 Description of Object and Methods of Research
As humidifier in research, of such variants were used:
• Water
• Aqueous urea solution
• Aqueous ammonium nitrate solution
The following samples were prepared to study nanoporous structure of PAN
granules and humidifier’s impact on the granule structure:
1. Granules of ammonium nitrate moistened with water and dried at a temperature
of 230–240 granules to a moisture content of 0.002 kg of moisture/kg of material
2. Granules of ammonium nitrate moistened with urea solution and dried at a
temperature of 230–240 ◦ F to a moisture content of 0.002 kg of moisture/kg
material (composition of the humidifier solution – 50% of carbamide and 50%
of water)
3. Granules of ammonium nitrate moistened with a solution of ammonium nitrate
and dried at a temperature of 230–240 ◦ F to moisture content of 0.002 kg of
moisture/kg of material (the composition of the humidifier solution is 40% of
ammonium nitrate and 60% of water)
At the first stage of the experiment, the moistened granules of ammonium nitrate
underwent heat treatment after humidification with various solutions. After this, an
analysis of their nanoporous structure was carried out.
A. E. Artyukhov et al.
2. Retentivity – amount of diesel fuel distillate (in percentage terms from granule’s
total weight) which remains in the granule after its transportation and surplus
runoff
3. PAN granule firmness
Absorptivity is defined by the total volume of pores (their form and nature are not
taken into account; the decisive factor is their size) and by the developed nanoporous
surface structure, which mostly consists of macropores (size is over 50 nm).
The retentivity normative indicator is provided by the internal “modification”
nanoporous structure. This structure includes mainly wavy mesopores (size 2–
50 nm). Firmness of the granule is defined by the core destruction degree (or
integrality). Low firmness of the granule has a negative impact on the production
ecological indicators (great deal of dust) and leads to the granules sealing. Thus,
a nanoporous structure must be developed on the granule surface and in its nearsurface layers.
Results of previous studies [11, 12] have shown that modification of ammonium
nitrate granules by humidification and subsequent heat treatment leads to changes
in the parameters of crystal lattice of samples. The porous surface of granules in this
case consists primarily of macropores, the presence of which allows to open access
to internal mesopores (which were also formed during the modification process).
The main objective of the work is to study the impact of humidifier type and
the number of humidification cycles on the surface and internal structure of PAN
granule nanopores and its quality indicators (holding and absorption capacity).
25.2 Description of Object and Methods of Research
As humidifier in research, of such variants were used:
• Water
• Aqueous urea solution
• Aqueous ammonium nitrate solution
The following samples were prepared to study nanoporous structure of PAN
granules and humidifier’s impact on the granule structure:
1. Granules of ammonium nitrate moistened with water and dried at a temperature
of 230–240 granules to a moisture content of 0.002 kg of moisture/kg of material
2. Granules of ammonium nitrate moistened with urea solution and dried at a
temperature of 230–240 ◦ F to a moisture content of 0.002 kg of moisture/kg
material (composition of the humidifier solution – 50% of carbamide and 50%
of water)
3. Granules of ammonium nitrate moistened with a solution of ammonium nitrate
and dried at a temperature of 230–240 ◦ F to moisture content of 0.002 kg of
moisture/kg of material (the composition of the humidifier solution is 40% of
ammonium nitrate and 60% of water)
At the first stage of the experiment, the moistened granules of ammonium nitrate
underwent heat treatment after humidification with various solutions. After this, an
analysis of their nanoporous structure was carried out.