Ferrous sulfate has many uses, and here are some common examples:

In industry, ferrous sulfate can be used as a reducing agent for dyes, inks, leather, papermaking, etc. It can also be used as a rust inhibitor, electroplating agent, water treatment agent for metal surfaces, etc.

In agriculture, ferrous sulfate can be used as a fertilizer to increase the iron content in the soil, promote plant growth, and can also be used as a fungicide, insecticide, herbicide, etc.

In medicine, ferrous sulfate can be used as an iron supplement to treat iron deficiency anemia, as well as a disinfectant, hemostatic agent, anti-inflammatory agent, etc.

In food, ferrous sulfate can be used as a food additive to increase the iron content in food, improve the color and taste of food, and can also be used as a preservative, antioxidant, etc.

In other aspects, ferrous sulfate can also be used as a laboratory reagent to prepare other chemical substances, as well as a developer for photography, pigment for art, and steganographic ink for literature.