For processing ferroslag dumps, SPE GRAVIKON supplies bespoke modular beneficiation plants with a capacity of 20-400 t/hour for the initial product.
Size of the initial material: up to 300 mm;
Size of the beneficiated material: 0 ... 40 mm;
Complex personnel: 3 ... 5 people / shift;
Energy consumption: 1.5 kW * h per ton of initial;
Area of the beneficiation site: 300 ... 600 m2;
Manufacturing / installation / commissioning: 6 ... 8 months;
First implementation of the technological solution: 2001, JSC Kazchrome, Aktobe Ferroalloy Plant;
Number of implementations on ferroslag: 7 (Kazakhstan / Ukraine);
Processed slags: ferrochrome (Kazakhstan); ferromanganese (Ukraine).
About the history of the issue: In 1998, at the request of JSC Kazchrome, Gravikon employees conducted research on the processing of ferroslag. The customer set the task of cleaning the slag from traces of ferrochrome to obtain environmentally friendly crushed stone. At that time, active road construction was underway in Kazakhstan and the government considered the Soviet ferroslag legacy as a source of millions of tons of crushed stone. However, the presence of chromium in the slag and its ability to transform into toxic compounds in the presence of moisture made it impossible to use it for road construction. Two years of research, including more than once in the presence of Kazchrome specialists, were required to convince the corporation of the effectiveness of the proposed solution - enrichment of ferroslag by hydraulic jigging. The first complex was launched on the basis of the Aktobe slag processing plant in 2001. As we guaranteed, the crushed stone was completely cleaned of chromium impurities. But more than that, two more commercial products were obtained: pure commercial ferrochrome and an industrial product that was sent for remelting. That is, the ferro slag was completely utilized by separating it into three commercial products: ferrochrome (sale) and industrial product with high ferrochrome content (remelting).
Depending on the material, productivity and customer requirements, the process flow chart can be simplified.
As is known, magnetic separation is also used in the process of ferroslag concentration. The reason is simple - no recycled water is needed. The main disadvantage of this technology is low extraction of useful material. The reasons are also known - the magnetic properties of the material are initially small, and during storage after 10/20/30 years they significantly decrease, or even disappear altogether. Therefore, up to 30 ... 40% of useful material remains in the tailings of magnetic separation. Another option is to combine pneumatic separation with magnetic separation. This technology can work, but its performance is significantly limited. The main limitation is the humidity of both the raw material (up to 5%) and the surrounding air. If it rains, the humidity increases and the separation efficiency drops to zero. If the raw material has high humidity, the effect is similar. Drying waste before separation is an economic absurdity.
In this situation, hydraulic jigging technology allows achieving almost 100% extraction of ferroalloys. With significantly lower energy costs per ton of the original. As European experience shows, ferroslag waste processed by magnetic separation (mainly in post-CMEA mills) can be re-enriched with high economic efficiency using the technological solutions we offer.