One of the earliest large-scale industrial applications of the pyrohydrolysis process, in addition to hydrochloric acid regeneration, was the production of high-purity magnesium oxide (MgO) for the refractory industry.
The process is capable of utilizing a wide range of magnesium-containing feedstocks. Suitable raw materials include concentrated waste brines from the potash industry as well as solid magnesium-bearing minerals and by-products, such as magnesite, dust collected from industrial gas cleaning systems, and serpentine.
Many of these materials would otherwise only be suitable for the manufacture of lower-grade refractory products or might even be regarded as industrial waste.
By applying the pyrohydrolysis process, they can instead be converted into high-purity magnesium oxide suitable for demanding industrial applications.
Titanium-bearing ores are leached with hydrochloric acid to produce titanium chloride solutions. In the spray roaster, these chlorides are thermally hydrolysed to form fine titanium dioxide powder while regenerating hydrochloric acid. The produced TiOโ is used in pigments, ceramics, and other high-performance materials.
Spray roasters are also used to regenerate spent hydrochloric acid from titanium dioxide production.
Iron- and titanium-containing waste acid is thermally decomposed, producing regenerated HCl for reuse and valuable metal oxides as by-products.
