Anhydrous Calcium Chloride Granulation & Drying System

The calcium chloride solution in this project is derived from ammonium chloride wastewater after an ammonia-stripping process. Since the initial calcium chloride solution has a relatively low concentration, it is first concentrated to over 30% using an advanced MVR evaporator system. The concentrated calcium chloride solution then undergoes spray granulation and drying in a Spray granulation and fluidized bed drying system, producing high-quality anhydrous calcium chloride granules.

This innovative process not only maximizes resource utilization but also converts industrial wastewater into a valuable product. By reducing waste discharge and improving operational efficiency, the project delivers significant environmental and economic benefits, supporting a more sustainable and circular production model.

In industrial production, drying calcium chloride — whether in its dihydrate or anhydrous form — presents several technical challenges due to its unique physical and thermodynamic properties:

1. Tendency to Clump During Drying

As the material heats up, calcium chloride can partially dissolve in its own water content, causing it to soften and stick together. This can lead to lumps or uneven drying.

2.High Heat Requirement

To fully remove the water and produce anhydrous calcium chloride, the material needs to reach very high temperatures — around 260°C — and stay at that temperature long enough to complete the drying.

3.More Complex Energy Needs

Drying calcium chloride isn’t just about removing surface moisture. The water that’s part of its crystal structure must also be removed, which takes extra energy and careful control of heat and airflow.

Because the calcium chloride solution obtained from the ammonium-stripping process of ammonium chloride wastewater is very dilute (less than 5%), an MVR evaporator is used to increase the concentration before granulation and drying. This ensures stable operation of the granulation and drying system while optimizing energy consumption.

The plant consists of the following sections:

1.MVR Evaporator: Concentrates calcium chloride solution up to around 30%.Due to the high boiling point elevation of calcium chloride solution, 30% is the maximum concentration achievable with an MVR evaporator. If a higher concentration is required, an additional forced circulation evaporator can be used.

2.Spray Granulation & Fluidized-Bed Dryer System: Converts the concentrated solution into 94% anhydrous calcium chloride granules.

3.Automatic Packing Machine: Packages the product into 25 kg bags or 1-ton jumbo bags, depending on market requirements.

Our innovative two-stage drying system separates the calcium chloride granulation and drying process into a main spray granulation unit and a secondary fluidized bed, delivering superior performance compared to conventional single-stage systems:

1. Higher Yield & Consistent Quality: Only pre-qualified material enters the second stage, ensuring uniform moisture content and high-quality granules.

2. Energy & Cost Efficiency: The main dryer handles less load, reducing energy consumption, heat demand, and overall investment.

3. Stable & Reliable Operation: Lower exhaust temperatures minimize dust and system strain, resulting in fewer shutdowns and smooth, continuous production.

This unique design guarantees smooth operation, consistently high product quality, and maximum efficiency in both investment and energy use.