The following three processes can be used for the separation of KCl from NaCl:
- Flotation
- electrostatic separation
- hot dissolution process
In flotation, KCl crystals treated with surface-active substances adhere to gas bubbles and are thus separated from sinking NaCl crystals. Through the robust LiquiSonic® measurement technology the flotation can be monitored inline and the KCl concentration can be determined precisely.
LiquiSonic® Sound velocity measurement in a KCl suspension
Application
The pre-ground raw salt is mixed with saturated brine and finely sieved (crystal size ~ 1 mm). Optionally, sludge and clay are separated and the pre-cleaned suspension is stored. In the flotation cells, surface-active reagents are used, which form a fine film exclusively on the KCl crystals. Introduced air bubbles bind the coated crystals. The KCl foam is mechanically separated from the surface. The non-binding NaCl crystals sediment and are in the post-treatmentthickened and clarified.
The purified KCl suspension is finally dehydrated by drying or centrifugation. Process water produced alongside the target product KCl is reused. LiquiSonic®offers robust concentration monitoring throughout the entire flotation process, serving quality assurance and process optimization.
Installation
The LiquiSonic® measurement technology is installed directly in the tank (storage, flotation) or in KCl-carrying pipelines. It is advisable to install from below for measurement in partially filled pipelines.
The LiquiSonic® Controller 30 can be connected to up to 4 sensors, allowing the flotation process to be monitored at multiple measuring points:
- Use of mother liquor
- Solution of raw salt (sylvinite)
- Clarification
- Flotation unit
- KCl dewatering
Typical measuring range:
Concentration range: 1100 - 1600 g/l
Temperature range: 10 to 40 °C
Customer benefits
The inline measurement system LiquiSonic® enables accurate analysis of process concentration using sound velocity. The robust sensor design without moving parts and the use of special materials (titanium) ensures long-term reliable process analysis and monitoring.
Further advantages for the user are:
- Optimal plant control through real-time information about the process state
- Increase in the efficiency of flotation
- Detection of process disturbances in seconds
- Savings in material, maintenance, and energy
The extraction of sylvinite (a mixture of potassium chloride KCl and sodium chloride NaCl) plays a crucial role in the production of mineral fertilizers and high-purity salts for the chemical and pharmaceutical industries.
