Sulfuric acid is a common chemical substance, and a common method for preparing sulfuric acid is called oilstone method.

1. Raw material preparation: Sulfur ore (a kind of ore with high sulfur content), air and water need to be prepared.

2. Refining sulfuric acid gas: firstly, the sulfur ore is crushed and added into a high-temperature furnace, and enough air is introduced to oxidize it. This process will produce sulfur dioxide (SO2) gas. Sulfur dioxide is cooled by condensation and collected.

3. Sulfur dioxide oxidation: introducing the collected sulfur dioxide gas into the reaction chamber to react with oxygen to obtain sulfur trioxide (SO3).

4. Synthesis of sulfuric acid: Sulfur trioxide reacts with water to produce sulfuric acid (H2SO4). This reaction is called water absorption reaction, and it is a violent exothermic reaction. Therefore, it is necessary to operate carefully and control the reaction temperature during the reaction.

It should be noted that the preparation of sulfuric acid is a complicated process involving high temperature and chemical reaction. Toxic gases and harmful substances are easy to be generated in the preparation process, so the relevant safety operation procedures should be strictly observed and carried out under the guidance of professionals.

Besides the oilstone method, there are other methods to prepare sulfuric acid, such as iron-copper method and oxidized sulfuric acid method. The specific preparation method will be different according to the actual needs and conditions. If you have a specific purpose or condition, you can provide more detailed information, and I can give a more specific answer.

Matters needing attention when preparing sulfuric acid:

1. Safe operation: The preparation of sulfuric acid involves high temperature and chemical reaction, so the safe operation procedures must be strictly observed. Wear appropriate protective equipment, such as laboratory clothes, goggles, gloves and chemical masks. Ensure that the operating environment is well ventilated to avoid the accumulation of toxic gases.

2. Corrosiveness: Sulfuric acid is a strong acid with strong corrosiveness. Avoid contact with skin, eyes or other body parts. In case of accidental contact, immediately flush with plenty of water and seek medical assistance.

3. Temperature control: In the process of preparing sulfuric acid, the reaction temperature needs to be controlled. Water absorption reaction is a violent exothermic reaction, and if the temperature is too high, it may lead to dangerous situations. Therefore, the temperature during the reaction should be carefully controlled and the suggestions in the operation manual should be followed.

4. Gas treatment: In the oilstone method, sulfur dioxide is produced by oxidizing sulfur ore. Sulfur dioxide is a toxic gas and must be treated correctly. Ensure proper ventilation system, and ensure the normal operation of equipment for collecting and treating sulfur dioxide gas.