The high-efficiency deep cone concentrator is a key equipment for
solid-liquid separation in large-scale quartz sand production lines (with a
daily processing capacity of ≥ 3000t), responsible for treating sand washing
wastewater and tail mortar (with a required bottom flow concentration of ≥ 65%
and overflow water sand content ≤ 0.1g/L), directly determining the water
resource recovery and utilization rate and environmental compliance rate. In
different regional conditions such as arid areas in the north (water scarcity)
and rainy areas in the south (surge in wastewater discharge), problems such as
large fluctuations in bottom flow concentration and excessive sand content in
overflow water are prone to occur, leading to water waste and environmental
penalties. Based on the sedimentation characteristics of quartz sand particles
and the production needs of different regions, summarize a three-step
optimization plan to improve the stability of the concentrator operation and
adapt to multi regional quartz sand production scenarios.
Step 1: Optimize the structural design of the concentrator to adapt to
regional working conditions and material characteristics
The core reasons for uneven bottom flow are improper cone angle design,
fabric structure, or mixing device failure, which need to be optimized according
to the regional water resources situation.
Adaptation of cone angle and overflow weir: In arid northern regions, it is
necessary to increase the concentration of bottom flow to reduce water resource
consumption. The cone angle should be selected between 60-65 ° to enhance the
sedimentation and aggregation effect of particles; The southern rainy areas need
to increase processing capacity and adjust the cone angle to 55-60 ° to avoid
slurry accumulation; When the horizontal deviation of the overflow weir exceeds
2mm/m, uneven overflow water flow leads to local sand accumulation. It is
necessary to calibrate with a level and install a serrated overflow weir to
improve the uniformity of overflow water collection.
Optimization of fabric and mixing structure: A single feeding port can easily
cause slurry deviation. Installing a "circular water distributor+guide cone" can
evenly distribute the slurry along the inner wall of the cone; When the wear of
the bottom flow agitator blades exceeds 3mm, the stirring force is insufficient
and the particle sedimentation is uneven. Replace the high chromium alloy
stirring blades and adjust the speed to 8-12 r/min. In northern regions, the
speed can be appropriately increased to 10-12 r/min to strengthen the bottom
flow concentration.
Step 2: Accurately regulate operating parameters, match regional water volume
with production load
Improper control of feed volume, bottom flow discharge rate, and liquid level
height can exacerbate fluctuations in concentration efficiency, and dynamic
adjustments should be made in conjunction with regional operating
conditions.
Balance of feed and discharge parameters: Water resources are scarce in
northern regions, and the feed rate is controlled at 85% -90% of the rated
value. The bottom flow discharge rate is adjusted to 1.2-1.5m ³/h to ensure
stable bottom flow concentration; When the feed volume increases sharply during
the rainy season in the south, the backup concentrator is activated, with a
single feed volume not exceeding 95% of the rated value, and the bottom flow
discharge speed is increased to 1.5-1.8m ³/h to avoid slurry overflow.
Liquid level and pressure regulation: When the liquid level is below 2/3 of
the cone, the settling time is insufficient, and the overflow water has a high
sand content; When it is higher than 3/4, it is easy to cause sand overturning.
The liquid level sensor is linked to the feed valve to stabilize the liquid
level in the range of 2/3-3/4 of the cone; In the low-temperature areas of
northern China (winter temperature ≤ 0 ℃), it is necessary to install insulation
layer on the liquid level monitoring pipeline to avoid freezing blockage and
parameter loss of control.
Step 3: Optimize the adaptation of flocculation agents to improve
sedimentation efficiency under different water qualities
Improper selection of reagents and imbalanced dosage can lead to slow
particle settling, and precise adaptation should be made based on regional water
quality characteristics.
Pharmaceutical selection is suitable for regional water quality: in northern
hard water areas (water hardness ≥ 250mg/L), anionic polyacrylamide (molecular
weight 12-15 million) is selected to improve particle flocculation and
agglomeration effect; In the soft water areas of southern China (with water
hardness ≤ 150mg/L), non-ionic polyacrylamide should be used to avoid chemical
failure; Before adding, the medication needs to be diluted to a concentration of
0.1% -0.3% to ensure sufficient dissolution.
Dynamic control of dosage: Adjust according to the solid content of the feed.
When the solid content exceeds 15%, the dosage should be 3-5g/t; When the solid
content is ≤ 8%, the dosage should be 1-2g/t; Install an online solid content
detector to provide real-time feedback and adjust the dosage. In northern
regions, the dosage can be appropriately increased by 10% -15% to cope with the
decrease in settling efficiency caused by low temperatures.
Daily maintenance should pay attention to: checking the operation status of
the mixer, the clarity of the overflow water, and the concentration of the
bottom flow every day; Calibrate the liquid level sensor and adjust the level of
the overflow weir every week; Clean the sand accumulation on the inner wall of
the cone every month and check the wear of the mixing blades; Equipment
insulation should be done well in winter in the north, and equipment sealing
should be strengthened to prevent water intrusion during the rainy season in the
south. By implementing the above measures, the bottom flow concentration can be
stabilized at over 68%, and the sand content in the overflow water should be ≤
0.08g/L, which is suitable for the solid-liquid separation needs of quartz sand
production lines in different regions of the north and south, and can improve
the water resource recovery rate. If there are still problems, it is recommended
to contact the manufacturer to optimize the equipment structure parameters based
on specific regional working conditions.