Is the cost of preparing magnesium oxide by chemical synthesis high?

Raw materials such as precious liquid ammonia, soda ash, and high-purity magnesium chloride are much more expensive than magnesite. The process is longer and consumes more energy. Refined brine → reaction precipitation → multiple water washes to remove chlorine → drying → high-temperature calcination → crushing and grading equipment requires high anti-corrosion (chloride ion corrosion), sealing (ammonia leakage), fine filtration, strict temperature control, and environmental protection/by-product treatment. Ammonium chloride and calcium chloride mother liquor recovery or treatment increases costs