Active lime rotary kiln line in Nigeria for a major steel company: limestone crushing, vertical roller mill dry grinding and rotary kiln calcination.

Customer & Feedstock

The customer is a major steel company in Nigeria. Quicklime is a first-class consumable in steelmaking: it forms the flux for slag making in the blast furnace and the electric arc furnace, and it also feeds the plant's flue gas desulfurization circuit. Steel production schedules do not pause for lime supply problems — which is exactly why the company built its own calcination line next to the mill.

Raw material is local limestone; feed moisture is managed in the grinding step by the vertical roller mill's air-swept drying.

Challenges & Requirements

• Supply security at steel-plant cadence. The kiln line had to be sized to cover the mill's full lime demand, including the FGD circuit, with headroom for campaign peaks.
• Tropical operating conditions. High ambient temperature and humidity work against lime storage and reactivity; the design addresses this at the cooling and storage end of the line.
• Fuel rate. As with every lime plant, the fuel bill dominates operating cost — the preheat-and-recover architecture (kiln exhaust used for feed preheating, cooler heat used for combustion air) was the design baseline.
• Spare parts and service logistics in West Africa. Long lead times from the region's ports make a packaged spares strategy and remote commissioning support part of the engineering, not an afterthought.

Solution & Equipment

Continuous line: crushing → air-swept dry grinding → rotary kiln calcination → cooling → storage.

Jaw crusher (SC series, SC80–SC304S) — primary crush of limestone.

Cone crusher (HPB / Symons series) — secondary crush to kiln-feed size.

Vertical roller mill (RMS / CRMS / CMS series) — dry grinding with in-line air-swept drying.

Rotary kiln (Ø4.0×60 m – Ø6.2×87 m class) — calcination to active lime.

Belt conveyor (DT / TC / ST series) — station-to-station transfer.

Process notes. The same drying-in-grinding logic as the Iran line: the vertical roller mill removes feed moisture before calcination, stabilising the kiln's burning window. The delivery includes a wear-parts pack sized for a West African spares logistics reality.

Design Results

• Continuous active lime covering mill flux plus FGD demand
• Drying integrated into grinding; no separate dryer
• Packaged spares + commissioning support for regional logistics

Why DMTC

• Built for the steel plant's real demand curve — flux and FGD loads modelled together, not one sized and the other hoped for.
• Regional service thinking — the spares package is designed for the ports and lead times the customer actually has.
• Proven kiln platform shared with DMTC lime and pelletizing lines worldwide.

Related Products

Rotary Kiln System · Vertical Roller Mill · SC Series Jaw Crusher