Iron(III) sulfate


Iron sulfate, is the chemical compound with the formula Fe23. Usually yellow, it is a salt and soluble in water. A variety of hydrates are also known. Solutions are used in dyeing as a mordant, and as a coagulant for industrial wastes. It is also used in pigments, and in pickling baths for aluminum and steel.

Production

Generally, ferric sulfate is used as a solution generated from iron wastes. The actual speciation is vague but its applications do not demand high purity materials.
Iron sulfate is often generated as a solution rather than being isolated as a solid. It is produced on a large scale by treating sulfuric acid, a hot solution of ferrous sulfate, and an oxidizing agent. Typical oxidizing agents include chlorine, nitric acid and hydrogen peroxide.

Natural occurrences

, a mixed iron-aluminium sulfate of chemical formula 23 is the name of mineralogical form of iron sulfate. This anhydrous form occurs very rarely and is connected with coal fires. The hydrates are more common, with coquimbite as probably the most often met among them. Paracoquimbite is the other, rarely met natural nonahydrate. Kornelite and quenstedtite are rarely found. Lausenite is a doubtful species. All the mentioned natural hydrates are unstable compounds connected with Fe-bearing primary minerals oxidation in ore beds. In the solutions of the ore beds oxidation zones the iron sulfate is also an important oxidative agent.