Salt lake resources are rich in China

and the Qarham salt lake in Qinghai Province is the largest potash fertilizer manufacturing base. However

a large amount of byproduct bischofite (MgCl2·6H2O) of the potassium fertilizer industry cannot be utilized effectively and are discarded back into the salt lakes. This has become the primary problem after extraction of potassium from salt lake. This paper presents a thermal plasma process for pyrolysis of bischofite. Thermal plasma was used as an ultra-high heat source to intensify the pyrolysis process. At the same time

the high temperature pyrolysis products were deposited to obtain high value-added MgO film. The deposition efficiency of MgO film was high

up to 3.2 mm·min-1. The particle size on the film was between 10 and 60 nm

and the MgO film exhibited a strong ultraviolet-green photoluminescence emission under the excitation of 325 nm He-Ne laser. The thermal plasma technique is simple and suitable for large-scale continuous process.