In term of processing potash ore, the Project has selected the Hot Crystallization as the process for ore processing. Hot Crystallization is a widely used in international potash mining and has been expertly tested and approved as the most suitable method.
The Bamnet Narong Deposit supplies a carnallitite ore ( KCI.MgCI 2.6H 2 O+NaCI), which is the natural potash deposit created from the seawater was captured in a basin for millions of years. After the seawater was evaporated the minerals in the seawater started sedimentation, which most components of carnallite consists of potassium chloride, magnesium chloride (MgCI) and sodium chloride (NaCI) as the principal, which are non-toxic, and our body can remove it out of the body without causing a hazard to our body.
Hot crystallization process uses the properties of solution that is different as follows.
- At the high temperatures, the KCI and MgCI2 can dilute water better than NaCI, so it can separate the NaCI first.
- The ability in dissolving KCL is reduced at the lower temperature that makes KCI crystallizes, but MgCI2 still dissolves water very well.
It can be seen that the ore processing technology of the project, does not use a chemical in the processing whatsoever.
Hot Crystallization Process:
The process of Hot Crystallization of Carnallitite ore consists mainly of following process:
1) Ore Crushing: by sort out the raw ore to have a size lower than 5 mm to suit water solution.
2) Hot Leaching: by separate sodium chloride (NaCI) out of carnallite by hot leaching by dissolving the raw ore with hot water at the 105°C based on the principle of the ability of different solutions. The said temperature can make the KCI and MgCI2 can dissolve better at from NaCI that can dissolve much less. After that it is filtered out the NaCI in the solid form out of the KCI and MgCI2, while the NaCI is stored temporarily at the ore tailings well as a component to refill it later.
3) KCI crystallization: the KCI and MgCI2 solution shall pass through the crystallizer to evaporate water and gradually reduce the temperature from 105 to 40 °C, so it can separate KCI 68% out of the MgCI2.
4) KCI cold leaching: wash the KCI 68% min. by cold water to derive of the KCI 95% min. as required.
5) Product drying: in the wet crystal form is sent to the centrifuge to separate water, then to the dryer to derive of the product with minimum KCI of 95% min. is ready for sale to the market later to derive of muriate of potash with the KCI content a minimum of 95% is the standard quality of the fertilizer market worldwide.