How to deal with wastewater in quartz sand production?
The wastewater generated during the production process of quartz sand mainly
comes from wet processing techniques, such as cleaning, scrubbing, flotation,
and grading. These wastewater may contain sediment, suspended solids, organic
matter, and small amounts of chemical agents. If discharged directly without
treatment, it will cause pollution to the environment. Therefore, the reasonable
treatment of production wastewater is an important link that cannot be ignored
in quartz sand production. The following are detailed methods and steps for
wastewater treatment:
1、 Sources and characteristics of wastewater
1. Source of wastewater
Cleaning process: Clean the sediment and wastewater generated during the
process of cleaning raw materials or finished products.
Scrubbing process: Clean the suspended solids and wastewater generated during
the operation of the scrubbing equipment.
Classification and flotation: wastewater containing a small amount of
flotation reagents and fine particle impurities.
Equipment cooling: Impurities that may be carried in circulating cooling
water.
2. Characteristics of wastewater
Contains a large amount of sediment and suspended solids.
Water may contain mineral impurities such as iron, calcium, magnesium,
etc.
A small amount of residual flotation reagents (such as collectors or
inhibitors).
2、 The main steps of wastewater treatment
1. Wastewater collection
Install wastewater collection systems at various stages of the production
line, including drainage tanks, collection tanks, and drainage pipelines.
Collect production wastewater in a centralized manner to prevent direct
discharge into the environment.
2. Precipitation and Separation
Primary sedimentation: Natural sedimentation of sediment particles in
wastewater through sedimentation tanks to reduce suspended solids
concentration.
Multi stage sedimentation: For wastewater with high suspended solids,
multi-stage sedimentation tanks can be used for step-by-step filtration.
Gravity separator: using gravity to further separate finer sediment
particles.
3. Flocculation and coagulation
Adding coagulants: Adding coagulants such as polyaluminum chloride (PAC) and
polyacrylamide (PAM) to accelerate the aggregation of small particles.
Coagulation reaction tank: Allow flocs to fully form in the coagulation
reaction tank for subsequent sedimentation or filtration.
4. Filtering treatment
Sand filter: further remove suspended solids and small particles through
quartz sand filter material.
Ultrafiltration system: using ultrafiltration membrane to remove impurities
such as particles and colloids, further improving water quality.
5. Chemical treatment
PH adjustment: Adjust the pH of wastewater to neutral by adding acid or
alkali.
Chemical removal: For residual flotation reagents, oxidants (such as
potassium permanganate) can be added for degradation.
6. Water quality testing and discharge
Water quality testing: Key indicators such as suspended solids content,
chemical oxygen demand (COD), and biological oxygen demand (BOD) of wastewater
are tested before discharge.
Standard discharge: Ensure that the treated wastewater meets local
environmental discharge standards.
3、 Reuse and recycling of wastewater
1. Water reuse system
Reuse of water treated in sedimentation tanks: Purified wastewater can be
used for non potable purposes such as cleaning raw materials and cooling
equipment.
Circulating water tank: Store the treated wastewater in the circulating water
tank for secondary use in production.
2. Water saving equipment
Install water-saving equipment (such as high-efficiency filtration devices
and circulation pumps) in key production processes to reduce the use of new
water.
3. Zero emission technology
Adopting evaporation concentration or membrane separation technology to
achieve zero discharge and resource utilization of wastewater.
4、 Common problems and solutions
1. Sediment accumulation in sedimentation tank
Problem: After long-term use, sediment accumulation in the sedimentation tank
may affect treatment efficiency.
Solution: Regularly clean the sediment in the sedimentation tank to prevent
blockage.
2. Excessive or insufficient flocculant
Problem: Improper dosage of flocculant can affect the flocculation
effect.
Solution: Determine the optimal dosage through experiments and configure
automatic dosing equipment.
3. Operation failure of wastewater treatment facilities
Problem: Equipment wear and tear or malfunction may lead to a decrease in
processing efficiency.
Solution: Regularly inspect and handle facilities to ensure normal
operation.
5、 Environmental and Economic Benefits
Scientific treatment of wastewater in quartz sand production can bring the
following benefits:
Environmental benefits: Reduce water pollution and protect the local aquatic
ecological environment.
Economic benefits: Achieve wastewater reuse and reduce production water
costs.
Social benefits: Enhance corporate image, comply with green production
concepts and environmental protection policy requirements.
A comprehensive wastewater treatment system is an important guarantee for the
sustainable development of quartz sand production lines. Enterprises should
design efficient and economical wastewater treatment plans based on their own
production situation and environmental requirements.