Ferronickel is a product of saprolite nickel ore processing, which is commonly used as a raw material for making stainless steel. In fact, 65 percent of global nickel production is used for ferronickel, the raw material for stainless steel!
In this article, we’ll take a closer look at one of Harita Nickel's most interesting nickel ore processing products: Ferronickel.
What Is Ferronickel?
Ferronickel is an alloy of nickel and iron, with a nickel content ranging from 20 to 40 percent.
This material is obtained by melting saprolite nickel ore in a furnace at temperatures reaching 1,500 degrees Celsius.
Ferronickel Manufacturing Process
Ferronickel is made using pyrometallurgy, a process that uses heat to extract minerals. The technology most commonly used in this process is the Rotary Kiln Electric Furnace (RKEF).
The RKEF process consists of several stages:
- Nickel ore separation
Nickel ore larger than 2 cm is separated from those smaller than 2 cm.
- Drying
The nickel ore is then dried using a rotary dryer. Here, the nickel ore is heated to 200-300 degrees Celsius, which reduces the moisture content from 40 to 20 percent.
- Calcination
To separate impurities from the nickel and iron, the dried ore is then melted in an electric furnace at temperatures reaching 1,600 degrees Celsius.
- Casting
The molten ferronickel is then cast into ingots and, after drying and cooling, can be packaged and shipped to the steel industry.
Differences Between Ferronickel and Nickel Matte
In general, ferronickel and nickel matte differ in their nickel content. While ferronickel has a nickel content of 20 to 40 percent, nickel matte has a nickel content of up to 78 percent.
And yet, both ferronickel and nickel matte are made from saprolite nickel ore, and both are processed using the same RKEF technology. So what makes nickel matte's nickel content higher?
Following the calcination process, nickel matte is produced by adding sulfur. Sulfur helps separate the nickel and iron, resulting in a higher nickel content.
The Many Uses of Ferronickel
Ferronickel is both corrosion- and heat-resistant, while also remaining malleable and easy to process. As a result, ferronickel has a wide range of applications in industry and everyday life, including:
- The raw material for stainless steel
Stainless steel is then used for household appliances, cars, and construction.
- Alloys in machine production
Ferronickel is also widely used as an alloy with other minerals to produce machinery and industrial components.
- Infrastructure
Due to its corrosion-resistant properties, ferronickel is widely processed into raw materials for bridges, high-rise buildings, and industrial pipes.
Ferronickel at Harita Nickel
Harita Nickel is an integrated and sustainable nickel mining and processing company operating on Obi Island, South Halmahera Regency, North Maluku Province.
Currently, Harita Nickel has 12 ferronickel production lines with a capacity of up to 120,000 tons of nickel per year.