RHEWUM supplies screens to METSO Minerals for classification of iron / nickel slag

09.10.2015, Macedonia

Valentina Weber, RHEWUM GmbH

RHEfino^®(U) screens enable significant contribution for the classification of Fe-Ni-Slag.

In April 2015, RHEWUM could enhance the long list of application references. High performance screening machines type RHEfino^® 350x290/3 were supplied to METSO Minerals Austria GmbH for the beneficiation of iron/nickel slag in Macedonia. The 3-deck screens employ direct excitation of screen mesh, which is typically used in the finest to medium grain size range.

The route of Fe-Ni slag processing determines screening devices, subsequently the 3-stage crushing system of jaw and cone crushers and vertical mills. In conjunction with the effectively concerted vibrating feed distributers type RHEmid 3500, today 100 tph (110 STPH) feed slag of grain size 0 – 6 mm (~1/4 in.) can be accurately classified into the product fractions 0 - 0.2 mm, 0.2 - 2.8 mm and > 2.8 mm (0 - 70 mesh, 70 mesh - 7 mesh and > 7 mesh).

With the aim to ensure maximized product qualities, RHEWUM supplied the upper screen decks with unbalanced motors. The lower decks, used for the finer cut-points at 0.2 mm (70 mesh), are equipped with electromagnetic vibrating heads like used for the RHEsono^® screen. This exceptional configuration leads to optimal separation results and minimizes screen cloth blockages consistently.

Fe-Ni slag is the glass-like co-product left over after the desired metal has been smelted from its raw ore. As it usually contains a certain amount of metal, recovery of these precious particles is recommended to guarantee sustainable production. After cooling down, primary crushing and hand picking, a combination of magnetic and gravity separation is often applied. Recovered metal products are subsequently re-used within the steel production.

Non-metallic fractions are no longer just deposited but used as secondary raw materials. Precisely screened into defined fractions, slag can be used as cheap building material or in concrete in combination with cement. Within this process section, RHEWUM screening machines accomplish the decisive contribution.