Iron ore shipments and export revenue from the US$14.3bn S11D mine both increased over threefold.
Peru's precious metals output fell in September due to dwindling ore grades at ageing mines, while most base metals gained.
One of the subsectors that suffered the most was the manufacturing of bodies for motor vehicles.
Austria's RHI concluded the merger with Brazilian rival Magnesita in October last year.
Canadian companies with gold, silver and lithium assets in Colombia, Argentina, Mexico and Nicaragua issue corporate updates.
Canadian companies operating in Colombia and Mexico provide updates.
The Brazilian steelmaker said net proceeds from the issue will be used to strengthen the Company's cash position, aiming to support its general purposes.
Brazil's three biggest steelmakers - Gerdau, Usiminas and CSN - have total debt of around US$15bn.