White Paper: Bulk Material Handling & Advanced Injection for Steel Mills: Optimizing Carbon, Lime & Furnace Dust Transport

The steel and foundry industry operates on the precise and efficient handling of a vast array of bulk materials, from essential raw inputs to critical additives and challenging by-products. The robust and reliable transport, storage, and injection of these materials are paramount for operational efficiency, product quality, and environmental compliance. Delta Ducon offers comprehensive, engineered solutions designed to meet the unique and demanding challenges of this vital industry.

The Crucial Role of Carbon and Lime in Steelmaking

At the heart of steel production lies the precise management and injection of key materials like carbon and lime, which fundamentally influence steel chemistry, energy consumption, and overall process efficiency.

Carbon (Coke Breeze) Handling and Injection:

Carbon is injected into molten steel primarily for two critical reasons. First, for carburization, ensuring the final steel product achieves the desired carbon content, which dictates properties like strength, hardness, and ductility for various steel grades. Second, particularly in Electric Arc Furnaces (EAFs), carbon is injected along with oxygen to create a "foamy slag." This foamy slag is vital for:

Energy Efficiency: Forming an insulating blanket over the molten metal, it significantly reduces heat loss, enabling longer arc operation and improving energy utilization.

Refractory Protection: It acts as a protective shield for the furnace refractory lining from the intense heat of the electric arc, extending furnace lifespan and reducing maintenance costs.

Improved Heat Transfer: It increases the contact area between the electrodes and the metal, leading to more efficient heat transfer and faster melting rates.

Chemical Reactions: The reaction of injected carbon with oxygen generates carbon monoxide (CO) bubbles, which vigorously stir the molten bath, facilitating metallurgical reactions and the crucial removal of impurities. Handling challenges for carbon and coke breeze include their abrasive and dusty nature, necessitating enclosed conveying systems and robust components.

Lime (Dolomitic & High Cal Lime) Handling and Injection:

Lime, including high calcium and dolomitic lime, serves as a critical fluxing agent in steelmaking, primarily used for slag formation and impurity removal. Its precise injection offers several significant benefits:

Slag Formation and Impurity Removal: Lime reacts with undesirable acidic oxides like silica (SiO$_2$), phosphorus (P), and sulfur (S) present in the molten metal. This reaction forms a stable slag that floats on top of the molten steel and can be easily removed, effectively purifying the steel. Lime is particularly effective in dephosphorization and desulfurization processes.

Refractory Protection: Similar to carbon, lime also contributes to protecting the refractory lining of the furnace by forming a protective and less corrosive slag layer.

Improved Slag Chemistry Control: Precise lime injection allows for highly accurate control over the slag chemistry throughout the steelmaking process. This precision is essential for achieving desired metallurgical results, optimizing energy consumption, and ensuring consistent product quality.

Energy Savings: Efficient and precise lime injection can lead to significant energy savings by optimizing slag conditions, reducing the need for costly reheating cycles, and improving overall thermal efficiency.

Environmental Benefits: Direct injection of fine lime particles into the bath at controlled speeds leads to more efficient utilization of the lime, reducing material waste, minimizing dusting, and improving the working environment compared to traditional methods of adding coarser lump lime. Handling challenges for lime include its cohesive and dusty properties, requiring well-designed pneumatic conveying systems to ensure smooth flow and prevent blockages.

Delta Ducon's Expertise and Technologies for Bulk Material Handling

With a long-standing history of innovation in bulk material handling, Delta Ducon specializes in advanced pneumatic conveying systems, sophisticated injection technology, and durable equipment crucial for the efficient feeding, transport, and precise injection of various bulk materials. Their solutions encompass:

Pneumatic Conveying Systems: Engineered for high-volume and highly abrasive materials, Delta Ducon provides heavy-duty dilute and dense phase pneumatic conveying systems. These systems are essential for moving diverse materials effectively throughout steel production facilities, minimizing product degradation and equipment wear.

Advanced Injection Technology: Critical for introducing additives and other materials into different stages of the steelmaking process, Delta Ducon's advanced injection capabilities ensure precision and efficiency. This includes sophisticated feeding mechanisms that allow for controlled material introduction directly into the molten bath, optimizing metallurgical reactions and material utilization.

Key Components for Demanding Environments: Delta Ducon integrates proprietary and robust components into their systems, specifically designed for the harsh conditions of the steel industry. These include:

Rotary Valves: Engineered for demanding applications involving abrasive or high-temperature materials, ensuring reliable feeding and discharge.

PERMA/flo Abrasion-Resistant Pipe & Elbows: Crucial for minimizing wear and ensuring longevity when conveying highly abrasive materials, significantly extending system lifespan and reducing maintenance.

KG Diverters and SPHERI Dome Valves: Providing versatile and reliable material flow control, these components ensure precise routing and isolation within complex handling systems.