Preparation of Heavy Soda Ash from Light Soda Ash
Heavy soda ash (Na₂CO₃) is an important basic chemical raw material. Compared with light soda ash, it has advantages such as higher density, more uniform particle size, better flowability, and less tendency to agglomerate. It is widely used in glass manufacturing, metallurgy, chemical synthesis, papermaking, detergents, and other fields. Tianli has deep expertise in the deep processing of soda ash, and has built a complete set of standardized production equipment for the conversion of light soda ash into heavy soda ash. It is compatible with both liquid-phase hydration and solid-phase hydration processes, and leverages our comprehensive technological advantages to provide customers with efficient, low-consumption, environmentally friendly, and intelligent production solutions, helping enterprises upgrade their products and enhance their market competitiveness.
I. Core Process Materials
The core materials for this production unit are light soda ash, water, and heavy soda ash. Light soda ash (raw material) is a white, powdery crystalline powder with the molecular formula Na₂CO₃, relative molecular mass of 105.99, and density of 0.5-0.6 g/cm³. It is easily soluble in water, highly hygroscopic, and has a purity ≥99.2%. It has fine particle size and poor flowability. The water is pure water with a resistivity ≥18 MΩ·cm, serving as the reaction medium and crystallization carrier to prevent impurities from affecting product purity. Heavy soda ash (finished product) is a white, granular crystalline powder with a density of 1.0-1.2 g/cm³, uniform particle size (0.8-2.0 mm), good flowability, and is not prone to moisture absorption and clumping. Its purity ≥99.5%. Strict control of reaction temperature, humidity, and molding parameters is required during the production process to ensure stable product quality.
II. Introduction to Core Process Flow
This device can flexibly employ both liquid-phase hydration and solid-phase hydration processes, both achieving a fully closed-loop process of raw material pretreatment → conversion and molding → drying and sieving → finished product storage. Specific details are as follows:
Liquid phase hydration process
1. Raw material pretreatment: light soda ash is crushed and screened to remove lumps and impurities, then sent to a dissolving tank. Pure water is added according to a precise ratio, and the temperature is controlled at 70-80℃. The mixture is stirred and dissolved to make a saturated soda ash solution. After precision filtration to remove trace impurities, pure soda ash mother liquor is obtained.
2. Conversion crystallization: pure soda ash mother liquor is fed into a crystallizer, and seed crystals are added to induce crystallization. The temperature ( 50-60℃ ) and stirring rate are controlled to allow soda ash crystals to grow slowly, forming dense soda ash crystals with a crystallization rate ≥98%. This can effectively prevent crystals from being too fine or clumping.
3. Solid-liquid separation: the crystallized slurry is sent to a centrifuge for separation, separating the heavy soda ash wet crystals . The mother liquor is returned to the dissolving tank for recycling, realizing full utilization of raw materials and reducing waste.
Solid-phase hydration process
1. Raw material pretreatment: light soda ash is crushed and screened to remove lumps and impurities, and then temporarily stored in a light soda ash silo.
2. Feeding: light soda ash is fed into the hydration machine in a quantitative manner according to the production capacity requirements via a quantitative feeding screw conveyor.
3. Hydration: Light soda ash is fed into the drum of the hydration machine . Simultaneously, water (usually from the washing liquid in the washing tower) is injected into the drum through a well-designed inlet pipe. The drum rotates continuously under the drive of a motor, and the soda ash powder and water inside are thoroughly mixed through tumbling and stirring.
4. Reaction and conveying: during the rotation of the drum, light soda ash reacts with water to form soda ash monohydrate. The drum is designed with spiral propulsion blades or a specific baffle structure to gradually propel the material forward while mixing.
5. Discharge: after the mixing and hydration reaction is complete, the resulting monohydrate soda ash is discharged from the outlet at the end of the drum and enters the subsequent drying process (such as fluidized bed). After dehydration, heavy soda ash is obtained.
Drying process
Both processes produce wet heavy soda ash crystals that are fed into an internally heated fluidized bed dryer. Utilizing both built-in heating elements and hot air for dual heating, a rapid, efficient, energy-saving, and environmentally friendly drying process is achieved.
1.Drying: hot air filtered and heated in the air distribution chamber suspends the material and forms a fluidized state, driving the material to tumble continuously to ensure uniform drying . At the same time, the internal heat exchanger directly contacts the material for heating, which greatly improves thermal efficiency, reduces heat loss, and accurately removes free moisture from the material.
2.Screening: the dried product is screened by a screening machine to remove unqualified particles and obtain the standard heavy soda ash finished product. Unqualified particles are returned to the pre-treatment stage for reprocessing.
3.Exhaust gas treatment: the production exhaust gas is treated by a cyclone dust collector and a scrubbing tower to meet emission standards. Dust is returned to the light soda ash silo, and wastewater is sent to the hydration machine for hydration and recycling, thus achieving clean production.
III. Core Technological Advantages
1. Technical advantages: simultaneously adaptable to both liquid and solid phase hydration processes, allowing for flexible switching based on customer capacity and raw material characteristics, offering strong adaptability; employs high-efficiency crystallization, granulation, and internally heated fluidized bed drying equipment . The internally heated fluidized bed utilizes a dual heating mode of built-in heating pipes and hot air, increasing heat utilization by over 30% compared to traditional drying equipment, resulting in significant energy savings and further reducing production energy consumption; the entire unit achieves a conversion efficiency of ≥98%, ensuring high raw material utilization; the equipment uses corrosion-resistant materials, facilitating convenient operation and maintenance, and its modular design enables continuous, large-scale production, adapting to different capacity requirements.
2. Energy consumption advantages: the energy consumption distribution of the two processes is optimized, and a waste heat recovery system is adopted to recover the waste heat in the drying process for raw material preheating. The liquid phase hydration method saves 20% energy compared with the traditional process, and the solid phase hydration method saves more than 15% energy. The energy consumption per ton of product is greatly reduced, significantly reducing the company's production costs.
3. Environmental advantages: the entire production process is closed, and the exhaust gas is purified and discharged in compliance with standards , with dust concentration lower than the industry standard; mother liquor and production wastewater are recycled, achieving zero wastewater discharge; no harmful waste residue is generated, which is in line with the concept of green and low-carbon development and meets environmental emission requirements.
4. Product advantages: the finished heavy soda ash has a purity of ≥99.5%, uniform particle size, good flowability, and is not prone to clumping, meeting industrial-grade standards; two processes can flexibly produce products of different specifications, adapting to the differentiated needs of glass, metallurgy and other fields, with stable product quality and strong market competitiveness.
5. Control advantages: equipped with a fully automatic PLC intelligent control system, it monitors key parameters such as temperature, humidity, crystallization rate, and finished product particle size in real time during the production process , achieving precise control throughout the entire process. It has automatic alarm and emergency shutdown functions, can be operated remotely, reduces manual intervention, ensures stable and safe operation of the equipment, and ensures uniform product quality.
Empowering deep processing with technology and forging high quality with expertise, Tianli focuses on the core needs of producing heavy soda ash from light soda ash. We have created efficient production equipment adapted to both processes, leveraging our comprehensive advantages in technology, energy consumption, and environmental protection to provide complete production solutions for various industries. This helps companies upgrade their products, reduce costs and increase efficiency, and jointly promote the green and sustainable development of the chemical industry.