System and method for calcining gypsum

System and method for precipitating salts

System and method for the production of alpha type gypsum...

Thermochemical method for producing hydrogen from hydrogen sulfi

Treatment of effluents

Treatment of sodium dithionite reaction mixture

Treatment of waste material

Use of high silicon Cr Ni steel in H.sub.2 SO.sub.4 manufacture

Use of wrought and cast materials and welding fillers for making

Vaporizing liquid sulfur dioxide with microwave radiation

Waste acid recovery process

Wet oxidation of sulphur and the capture of generated heat

Working up sodium sulfate-containing residues

Working up spent sulphuric acid simultaneously with sulphate sal