New and improved cement production for Fortaleza

Votorantim Cimentos’ first grinding plant, located in the Pecém Industrial and Port Complex, in the state of Ceará (CE), in the northeast of Brazil, started operating in 2008 to primarily serve the market in the metropolitan region of the state capital, Fortaleza. At the time, its cement production capacity was 200 000 tpy. The facility received its clinker from another Votorantim Cimentos plant located in the city of Sobral, also in the state of Ceará, transported via rail and road.

The development of a steel operation in the Pecém Complex and the consequent availability of slag for the production of cement made it possible to expand the existing grinding plant from 200 000 to 1 million tpy. The new plant, which receives clinker from the same source (resulting in lower production costs), enabled the expansion of the market radius and an improvement in the quality of the services provided to customers. In addition, the availability of slag in Pecém enabled the company to postpone clinker production investments in other locations, aligning the project with Votorantim Cimentos’ 2030 Sustainability Commitments.

The plant

Occupying an area of 948 500 m², Votorantim Cimentos’ Pecém plant has an open-air slag storage capacity of 800 000 t and a closed storage clinker capacity of 21 200 t in addition to other cement grinding additives.

These materials are handled by yellow line equipment. The open-air slag stock is reclaimed by an excavator equipped with a crusher bucket to process the clods that form over time and a hopper that feeds the mill’s dosing silo.

The plant is equipped with a 3000 kW FLSmidth OK-33 mill with two inlets for raw materials, one dry and one wet – the latter to reduce clogging; both of them have rotating locks, one of which is heated.

The Hamon bag-type filter is directly attached to the mill, and the cement is transported to the silo by chutes and elevators. The grinding unit produces 115 t of CP III cement per hour with an average slag addition of 60 – 70%, which reduces the company’s environmental footprint.

The facility chose vertical mills instead of ball mills because of a recognised higher drying capacity and lower electricity consumption, especially when working with higher slag consumption.

To provide the energy necessary to dry wet slag (approximately 10% and 13%, depending on the time of year) a Dynamis Hot Gas Generator (HGG), with the capacity to generate up to 12 GCAL/h (or 50 GJ/h) was installed. In line with Votorantim Cimentos’ goal of reducing emissions, the equipment can be powered by biomass or low-sulfur petroleum coke.

The fuels are stored in a closed 1300 t capacity warehouse. The installed HGG can operate in a wide range of capacities, varying between 30% and 100%, which is important for the production of cements that require lower energy input.

To resolve the issue of lumps forming in the silo, the cement produced is cooled to a temperature below 70°C by an FLSmidth cement cooler. Cooling water is kept in a closed circuit made up of cooling towers, which not only minimises water consumption but also aligns with the company’s sustainability goals.

To provide flexibility, the company chose a multi-chamber silo for cement storage. This Claudius Peters silo has a 10 000 t capacity divided into one 4000 t and three 2000 t chambers. It is equipped with a bulk loading trunk with a loading capacity of 250 tph.

The silo feeds a Haver & Boecker bagging machine with a capacity of 180 tph to fill 50 kg bags. It works together with a Beumer palletiser with the similar capacity. This system also allows for the shipment of cement in bags of different sizes.

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