The ceramic fracturing sand granulator is the core equipment for high-end
fracturing sand production, responsible for processing raw materials such as
clay and bauxite into spherical particles (with a required sphericity rate of ≥
92% and compressive strength of ≥ 69MPa), directly determining the service
performance of fracturing sand in high-temperature and high-pressure
environments of oil and gas wells. If the ball formation rate is low (less than
85%) and the particle strength is insufficient (less than 50MPa), it will cause
particle breakage and a decrease in diversion capacity during fracturing
construction. Based on the characteristics of strong viscosity and high
temperature roasting of ceramic fracturing sand raw materials, a three-step
investigation method is summarized to quickly restore granulation quality.
Step 1: Optimize granulation structure and speed - the core components
determine the spherical shape
The improper structure and speed of the granulation disc/drum are the main
causes of poor ball formation.
Inappropriate inclination angle or edge height of granulation disc: If the
inclination angle is less than 35 °, material accumulation cannot form rolling;
Greater than 45 °, the material slides too quickly and the ball forming time is
insufficient; If the edge height is less than 20cm, the material is prone to
splashing. Adjust the tilt angle to 38 ° -42 ° and increase the edge height to
25-30cm to ensure that the material forms a "rolling compaction" cycle inside
the tray; Install wear-resistant rubber lining plate (thickness 10mm) on the
inner wall of the disc to enhance material adhesion and promote spherical
formation.
Speed too fast or too slow: When the speed exceeds 35r/min, the centrifugal
force of the material is too strong, forming flat particles; Below 20r/min, the
rolling force of the material is insufficient and the agglomeration is severe.
Use a tachometer to detect and adjust to 25-30r/min, and achieve stepless speed
regulation through a frequency converter; According to the dynamic optimization
of raw material viscosity: low speed (25r/min) is selected for clay raw
materials with high viscosity, and high speed (30r/min) is selected for bauxite
raw materials with low viscosity.
Step 2: Calibration of Material Proportions and Water Addition Control - Raw
Material Adaptation and Strength Enhancement
Improper raw material ratio and moisture content can exacerbate problems with
ball formation and strength.
Imbalance in raw material ratio: clay content less than 30%, insufficient
particle viscosity, and easy breakage; The content of bauxite is less than 50%,
and the strength is insufficient after high-temperature roasting; Additives
(such as bentonite) are less than 1%, resulting in poor ball stability. Mix
according to the ratio of "clay 35% -40%, bauxite 55% -60%, bentonite 3% -5%" to
ensure that the uniformity of raw material mixing is ≥ 95%; Install a dual axis
mixer and control the mixing time within 8-10 minutes to avoid local mixing
deviation.
Improper amount or method of adding water: if the moisture content is less
than 18%, the material is difficult to form balls when dried; Above 25%, the
material adheres to the disk wall and forms large blocks; Adding water at a
single point leads to uneven distribution of moisture. Make up water evenly
through spray type water adding device (atomized particle size 50 μ m) to
control the water content at 20% -22%; Install an online moisture detector,
provide real-time feedback data, automatically adjust the amount of water added,
and avoid manual operation deviation.
Step 3: Adapt to roasting requirements and pretreatment - ensuring stability
at the source
Insufficient pre-treatment and granulation of raw materials can affect the
roasting effect and final strength.
Uneven particle size or high impurities in raw materials: the particle size
of raw materials exceeds 2mm, and there are many internal pores after ball
formation; Mixing impurities such as quartz sand and gravel (with a hardness
exceeding level 8) can easily cause cracks during roasting. Add ultrafine
grinding process before granulation to control the particle size of raw
materials below 200 mesh; Install a vibrating screen (aperture 1mm) to remove
large impurities and hard objects, ensuring that the purity of the raw materials
is ≥ 98%.
Improper maintenance or roasting connection of raw balls: Raw balls are
roasted directly without maintenance, resulting in rapid evaporation of water
and cracking; The maintenance time is too long (over 24 hours), and the surface
air drying affects the viscosity. Maintain the raw balls in an environment with
humidity of 60% -70% and temperature of 25-30 ℃ for 8-12 hours, and then
transfer them to the roasting kiln; Before roasting, pre dry the raw balls in a
drying furnace (temperature 120 ℃) to reduce the moisture content to below 5%,
in order to avoid explosion during roasting.
Daily maintenance should pay attention to: cleaning the adhesive materials on
the inner wall of the granulation disc/drum every day, and checking the wear of
the lining plate; Calibrate the speed, water addition, and raw material ratio
weekly, and tighten the bolts of the transmission mechanism; Maintain the spray
water feeding device every month and replace the clogged nozzle. By implementing
the above measures, the balling rate of ceramic fracturing sand can be increased
to over 94%, and the compressive strength can be stabilized at over 75MPa,
meeting the requirements of high-end oil and gas well fracturing construction.
If there are still problems, it is recommended to contact the manufacturer to
optimize the granulation structure and raw material adaptation parameters, and
match the specific requirements of the roasting process.