One-and-half Step Reduction Process
The One-and-half Step Reduction Process, also known as the Tomiyama Process and the Budden Process, is an innovative, cost effective iron and steel making process that has been used in Japan since the late 1940s. The process involves two key steps that have the net effect of reducing iron ore to iron. The process is a cost-effective way of producing high-quality iron and steel that has been applied in commercial steelmaking processes.
The first step of the process involves heating iron ore and limestone together in a furnace that operates at a temperature of around 1500 degrees Celsius. The heat-treatment causes the ore to be oxidised with oxygen from the air, and undergo a process of carbon absorption from the limestone. This results in the formation of a substance called pig iron, which is composed of iron, carbon and other elements.
The second step of the process, the reduction, involves the direct addition of a reducing agent to the pig iron. The reducing agent, typically coke or charcoal, reduces the oxygen in the pig iron and causes it to become iron again. This involves yet more heat-treatment, causing the reduced ore to spilt into two components: one part which is liquid iron, and the other is a slag-like substance composed mainly of silicates, impurities and other elements, which is manually removed from the reaction chamber.
Once this second stage of the process is complete, the now liquid iron is cooled and poured into moulds ready for use as either pure pig iron (also known as foundry pig) or alloyed with other metals as steel.
The One-and-half Step Reduction Process is a complete, cost-effective method of producing high-grade iron and steel, with exceptional properties. Its core steps involve the heating and reduction of iron ore and other elements, making the process more efficient and allowing more iron to be produced with less labour and resources. The method is ideal for a variety of iron and steel making applications, such as the production of high-reliability tools and components, along with the construction of general-purpose steels and alloys.
The One-and-half Step Reduction Process is widely accepted as being one of the most cost-effective iron and steel making processes available, and is used in a number of major steelmaking companies across the world. Numerous improvements to the process have been made in the years since its introduction, further increasing its economic and industrial viability. In particular, the use of chemical additives, advanced temperature-control systems and improved metal stirring systems have allowed for a marked increase in both productivity and overall product quality.
