What is sulfuric acid contact process? Introduction and History

The sulfuric acid contact process, also known as the Meyer refining process and Saar refining process, is a chemical process to purify metal sulfide ores by converting them into metal. It employs an electric arc furnace with additional equipment for tapping and treating the molten metal. Both are typically used in combination with a concentration plant. The first stage is usually conducted on site at the mine or quarry; if not, it's done at a concentrating facility near or at port facilities.

What is sulfuric acid contact process? Introduction and History

Sulfuric acid is the key catalyst in the galvanizing industry. It's used for the production of lead, zinc, and copper alloys for protecting steel and iron from rust. Also, it's used to produce sulfur dioxide that's employed in other chemical industries like the rubber, dyeing and pharmaceutical sectors. Sulfuric acid is also used to produce phosphoric acid that is used in detergents, fertilizer and prepared papers; nitric acid that's employed in various metals treatments; hydrochloric acid that's important industrial solvent; water treatment; blast furnace linings; and agricultural pesticides including fungicides, herbicides, rodenticides...etc. Sulfuric acid is also used in the production of dyes, synthetic rubbers, tanning agents and other compounds.

Supplies and equipment will be discussed in this article as it is a very vital part for operations in the ore refining process. We will also discuss various procedures involved in running your own sulfuric acid refining plant.

The Sulphuric Acid Process: The Traditional Method of Bleaching Lead Ores

The Sulphuric Acid process has been used to reduce the lead content of lead ores for its use as a pigment and an abrasive because of its high boiling point (74.5 ℃/159 °F). The sulfuric acid process is also used to produce lead sulfate or arsenate which are used in the production of lead arsenate and lead nitrate respectively.

The sulphuric acid process begins with the separation of oxide and nonoxides, which require high energy consumption in air furnaces. The lead is then melted in presence of sulfuric acid with the help of a refractory crucible enclosing a platinum electrode. The molten mixture is transferred to a heating chamber where it is heated to a temperature of 750 ℃ (1250°F) for two hours. This initial heating stage is used for removing oxides from the molten mixture and making it more soluble.

The molten mixture is then transferred to a tube furnace that is used for further heating process. The molten mixture is called Limonite, and the lead oxide of Limonite is called Limonite ore (LMO). The Limonite ore that has been removed from the tube furnace is called LMO slag.

The metal that remains at the end of this process contains up to 95% metal by weight along with your impurities such as oxides, sulfates, nitrates and carbonates. It's a complex mixture which requires extensive boiling and purification methods before it can be used as an alloy. The Limonite ore can be further processed by other industries like refineries and petroleum industries.

Uses of sulfuric acid contact process

1. The sulfuric acid process has been used in lead refineries to reduce the lead content of lead ore. Besides being used as a pigment and an abrasive, it's also important in the production of lead sulfate or arsenate which are employed in the manufacture of lead arsenate and lead nitrate respectively.

2. Sulfuric acid is also used to produce phosphoric acid that's employed in detergents, fertilizers and prepared papers; nitric acid that's employed in various metals treatments; hydrochloric acid that's important industrial solvent, water treatment; blast furnace linings; and agricultural pesticides including fungicides, herbicides, rodenticides...etc.

3. Sulfuric acid is also used in the production of dyes, synthetic rubbers, tanning agents and other compounds.

4. It's also used in the metallurgical industry for cleaning and removing manganese from molten iron, nickel and cobalt from their respective ores, extracting zinc from its ore; manufacture of ferrous sulfate for use as a supplement for livestock and poultry; manufacture of sulfur trioxide for discharge printing ink by the offset method; manufacture of lead azide and ethylenediamine.

5. The Meyer refining process or Saar refining process is similar to the pyrometallurgical process where ore is refined in an electric arc furnace.

Conclusion

The sulfuric acid contact process has been used to reduce the lead content of lead ores for its use as a pigment and an abrasive because of its high boiling point (74.5 ℃/159 °F). The sulfuric acid process is also used to produce lead sulfate or arsenate which are used in the production of lead arsenate and lead nitrate respectively.