Polyaluminum Chloride (PAC)
Polyaluminum chloride (PAC) is currently the most widely used inorganic polymeric flocculant in the water treatment field. With its advantages such as rapid flocculation, good sedimentation effect, wide applicable pH range, and no secondary pollution, it is widely used in tap water purification, industrial wastewater treatment, paper sizing, dyeing and printing decolorization, and food processing wastewater treatment. Tianli has deep expertise in water purification material production equipment, building a complete set of standardized polyaluminum chloride production equipment. Utilizing mature and advanced production processes, we balance large-scale mass production with meticulous quality control. Leveraging our comprehensive technological advantages, we provide customers with efficient, low-consumption, environmentally friendly, and intelligent production solutions, contributing to the water treatment industry's quality improvement, efficiency enhancement, and green development.
I. Properties of Core Materials
The core materials of this production unit include raw materials, reaction media, and the finished product polyaluminum chloride (PAC). The main raw materials are aluminum hydroxide, calcium aluminate powder, and industrial-grade hydrochloric acid. Aluminum hydroxide is a white powdery solid with a purity ≥98%, insoluble in water, and is the core aluminum source for PAC synthesis. Calcium aluminate powder is a gray powder containing calcium oxide and aluminum oxide, used as a modifier to adjust basicity and improve the product's flocculation performance. Industrial-grade hydrochloric acid (30% concentration) is a colorless, transparent liquid with strong corrosiveness and high volatility, used as the acidification reaction medium. The finished product polyaluminum chloride, is a yellow or yellowish-brown liquid (liquid PAC) or pale yellow powder (solid PAC), with the molecular formula [Al₂(OH)ₙCl₆₋ₙ]ₘ. Its basicity is controlled between 40% and 90%, and its alumina content is ≥28%. It has strong adsorption properties, and the production process requires strict control of reaction temperature, acidity, and basicity to ensure stable product flocculation performance.
II. Introduction to Core Process Flow
1. Raw Material Feeding and Polymerization Reaction Section
Calcium aluminate powder and aluminum hydroxide (Al(OH)₃) are quantitatively fed into the reactor through screw conveyor. Simultaneously, 31% industrial hydrochloric acid and steam are added to the reactor. Under stirring and steam heating conditions, the hydrochloric acid first reacts with the calcium aluminate powder to produce aluminum hydroxide, and then further reacts with existing and newly generated aluminum hydroxide in the system to produce aluminum trichloride. Subsequently, under conditions of excess aluminum source, the hydrolysis polymerization reaction is completed to produce a crude polyaluminum chloride (PAC) solution. The acidic tail gas generated during the reaction is led out from the top of the reactor.
2. Tail Gas Treatment and Wastewater Recycling Section
The acidic tail gas generated from the reactor is sent to a spray tower. The spray absorbent washes and absorbs harmful components such as HCl in the tail gas. The treated tail gas meets emission standards. The washing wastewater generated by the spray tower is returned to the reactor through a recycling pipeline, realizing the resource recycling of wastewater and reducing material loss and wastewater discharge.
3. Solid-Liquid Separation Section
After the reaction, the PAC crude liquid is pumped into a plate and frame filter press for solid-liquid separation under pressure. Unreacted solid residues and other impurities are removed, yielding a clarified PAC filtrate. The separated filter residue is disposed of as solid waste in compliance with regulations.
4. Intermediate Storage and Finished Product Storage Section
The clarified PAC filtrate after filtration is pumped into a temporary storage tank for temporary storage. After quality homogenization, it is then pumped into a finished product storage tank for storage as qualified liquid polyaluminum chloride product for subsequent filling or external supply.
III. Core Technological Advantages
1. Energy Consumption Advantages: optimized energy allocation throughout the entire process, equipped with a waste heat recovery system, recovers waste heat from the reaction and drying stages for raw material preheating, reducing overall energy consumption by more than 20% compared to traditional production equipment, significantly reducing energy consumption per ton of product and enterprise production costs, thus improving economic efficiency.
2. Environmental advantages: the entire process adopts a closed-loop production system. Acidic tail gas is absorbed by alkaline solution and discharged in compliance with standards; dust concentration is lower than industry standards; production wastewater is neutralized and filtered before recycling, achieving zero wastewater discharge; no harmful waste residue is generated, aligning with the green and low-carbon development concept and fully meeting environmental emission requirements.
3. Product advantages: the basicity and alumina content of the finished polyaluminum chloride are precisely controllable; liquid products dissolve quickly; solid products are convenient to transport and store; high purity, low impurity content, stable flocculation effect, and wide applicability, suitable for different water treatment scenarios such as tap water and industrial wastewater; product quality meets national industrial standards, and has strong market competitiveness.
4. Control advantages: equipped with a fully automatic PLC intelligent control system, it monitors key parameters such as reaction temperature, pressure, acidity, basicity, and finished product purity in real time, achieving precise control throughout the entire process. It features automatic alarm and emergency shutdown functions, remote operation, reduced manual intervention, minimized human error, and ensured stable and safe operation of the equipment, resulting in consistent product quality.
Empowering the water purification industry with technology, and creating superior products with professionalism. Our company focuses on the core needs of polyaluminum chloride production, building efficient, environmentally friendly, and intelligent production equipment. Leveraging our comprehensive advantages in technology, energy consumption, and environmental protection, we provide complete production solutions for various industries, helping enterprises reduce costs, increase efficiency, achieve green development, and jointly build a clean water environment.