Metal Magnesium Smelting Method: Pidgeon Method

1. Methods of magnesium metal smelting

There are three main methods for producing magnesium metal: electrolysis, silicothermic process (Pidgeon method), and carbothermic process. The Pidgeon method is an important method for producing magnesium metal in China because it has a short refining process, low investment, fast factory construction, and low cost. However, the melting technology is relatively backward, and the resource and energy consumption during the production process is relatively large, resulting in serious pollution.

The essence of the Pidgeon method for refining magnesium is to reduce magnesium oxide to magnesium vapor through silicon (or aluminum) under high temperature and vacuum conditions when calcium oxide is present and separate it from the solid calcium silicate (2CaO·SiO2) generated by the reaction. The process can be divided into four stages: dolomite calcination, raw material preparation, reduction, and refining.

2. Advantages, disadvantages, and development of Pidgeon and electrolytic methods for magnesium metal smelting

The Pidgeon method, its process and equipment are relatively simple, with low investment and flexible production scale. The purity of the finished magnesium is high. The furnace is small, easy to build, and has low technical difficulty. Moreover, it can directly use the resource-rich dolomite as raw material.

The main disadvantages are low thermal utilization efficiency, short life of the reduction tank, high cost of the reduction furnace, labor-intensive, and discontinuous production process. And if you may have interest, we can provide a reasonable magnesium scrap price.

To address these shortcomings, a series of technical improvements have been made. The structure of the reduction tank has been improved, new types of insulation materials have been used, thermal short circuits have been cut off, and the comprehensive thermal conductivity of the internal medium has been increased. The furnace type has been improved, for example, by using a water-coal slurry to heat the bottom of the reduction tank uniformly. New types of burners, such as regenerative burners, are used to recycle and utilize the emitted waste gas. Modern control technology and mechanized loading and unloading equipment are also used.

Compared with the Pidgeon method, the electrolytic method for refining magnesium has the advantages of energy saving, good product uniformity, easy large-scale industrial production, continuous production process, and lower production cost, and is an energy-intensive industry.

However, the electrolytic method for Mg metal including magnesium metal block smelting also has the following disadvantages: the production process of preparing anhydrous magnesium chloride is difficult to control; the dehydration of magnesium chloride hexahydrate requires high temperature and acidic atmosphere, resulting in high energy consumption and severe equipment corrosion; the wastewater, waste gas, and waste residue generated during the electrolytic production process cause pollution to the environment and incur high treatment costs. And we also have am60b magnesium alloy for sale.

To address these shortcomings, there are also corresponding measures, such as converting the electrolytic raw materials from granular magnesium chloride to spherical magnesium chloride through dehydration with anhydrous hydrochloric acid, thereby reducing energy consumption.