Stack it high

Despite the potential for digital automation to make operations far more efficient, past experiences with automation projects going over budget or overshooting deadlines created hesitation in the mining industry.

BlueScope Steel commissioned the BulkExpert™ automation system, a 3D scanning technology, at its Port Kembla stockyard in Australia, three years ago. The initiative has provided BlueScope Steel with valuable experience to help shape their future automation projects.

Operational opportunities

When lump ore and fines unload from a ship, they are stacked to the primary or secondary yards with large volumes of iron ore in continuous transit. Each incoming capsize vessel carries another batch to be unloaded and reclaimed. The average turnaround time is 7-10 days for the mixing bed.

When the stacking operation is down, it limits the offloading operation and ships have to stay at the berth. This potentially increases demurrage charges the longer the cargo stays on the terminal.

"Process control and stability at maximum feed rates are some of our key metrics, hence our stacker reclaimer operations were identified as an area of opportunity for automation," says Derek Sheppard, maintenance and asset development manager at BlueScope Steel.

The company considered different options, ranging from complete replacement of the massive machines, which date back to 1974, to simply refining existing processes.

"We determined that upgrading our existing stacker reclaimers was the best option in terms of return on investment. This allowed for automated operations based on orders entered by engineers from a control room environment," he explains.

The old machines with original electrical equipment showed significant corrosion from working in harsh environments. To find the right solution, BlueScope Steel assessed the capacity of the machines and determined that the design throughput rate was sufficient and compatible with the rest of the materials handling equipment.

Sheppard says, "After factoring in restoration, we explored options for automation in order to help ensure repeatability of processes, and that our equipment would operate within design parameters."

A revelation

For BlueScope Steel, shipping discharge rates and utilisation of stockyard are areas where automation realises significant operational efficiencies. Even though, the payback of less than 18 months is convincing, BulkExpert also provides data on the equipment performance, which can reduce or prevent overload or damage, such as to conveyor belts.

In preparation, BlueScope Steel had met with other BulkExpert customers to understand the full scope of the benefits, some of which are difficult to quantify.

Besides significantly reducing operating costs, improved throughput and the reduced risk of demurrage, other benefits include well-structured stockpiles and real-time accounting of stock inventory levels. Automatizing the stockyard reduced flowrate variances by >40% and stacking/reclaiming throughput increased by 90%: from 10-12,000 to 19,000 tpd.

Keep focusing on profitability

Port Kembla, like all integrated steelworks, faces the ongoing challenge of achieving and maintaining manufacturing efficiency to remain profitable throughout the commodity cycle. Sheppard sees automation as the route to ensure effective operations and hedge against uncertainty. "Additionally, labour also adds a significant cost and will always have to be managed to ensure that manufacturing remains cost effective."

The choice between automation versus manual operations inevitably comes down to a financial ROI with efficient, complex and repeatable manual operations having greater longevity over the contrary, according to Sheppard.

"As technology develops and pricing becomes more affordable, the opportunity for digitalisation and automation increases. You need to bring the operation to such a profitable level that you are not worried what the steel price will be tomorrow," he adds.

Spot price trading with real-time inventory survey

• BulkExpert™ gives a real-time overview of the stockyard inventory, allowing for spot-price trading. With precise data to the decimal on the stock at any given time, companies can either replenish their stock or sell exactly when and where the spot price is right. Currently stock is guesstimated on a weekly basis, making it impossible for companies to sell/buy strategically
• Bauxite, coal, iron ore, limestone, quartz, sinter, coke, gabbro, urea, ammonium nitrate and phosphate are some of the commodities handled by BulkExpert systems