Title

EVALUATION OF THE LADLE FREE OPENING RATE IN CONTINUOUS CASTING AS A FUNCTION OF NOZZLE SAND COMPOSITION

EVALUATION OF THE LADLE FREE OPENING RATE IN CONTINUOUS CASTING AS A FUNCTION OF NOZZLE SAND COMPOSITION

Authorship

MARTINS, RODRIGO SEARA; MAIA, MAGNO ANGELO DE ANDRADE; BARROS, FABIANO RIBEIRO DE ALMEIDA; PEREIRA, MARIA LUIZA GONÇALVES; STOCO, BRUNO NERY; OLIVEIRA, SIMÃO PEDRO DE

MARTINS, RODRIGO SEARA

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MAIA, MAGNO ANGELO DE ANDRADE

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BARROS, FABIANO RIBEIRO DE ALMEIDA

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PEREIRA, MARIA LUIZA GONÇALVES

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STOCO, BRUNO NERY

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OLIVEIRA, SIMÃO PEDRO DE

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DOI

10.5151/2594-5300-42693

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Abstract

Steel remains the most widely used industrial material in the production of capital and consumer goods, with applications spanning civil construction, infrastructure, mechanical equipment, metal products, automotive industry, and domestic appliances. Since 1950, global steel production has grown steadily, reaching approximately 1.88 billion tonnes of crude steel in 2024. Currently, around 96% of global steel output is produced via continuous casting. In Brazil, the use of continuous casting is even more predominant, accounting for approximately 99.5% of national steel production. The operational efficiency of continuous casting relies heavily on the proper sequencing of molten steel ladles, which depends on achieving “Free Opening” of the ladle gate valve—that is, the immediate flow of steel upon valve activation. This study aims to quantify the costs associated with the occurrence of “Non-Free Opening”—a condition in which the steel does not flow spontaneously through the valve, requiring oxygen injection to initiate the flow. The analysis covers multiple steelmaking routes, grouped into four main categories: simple route, RH route, double refining, and triple refining. The study examines the influence of sand composition on the free opening rate, assesses the financial implications of flow initiation failures, and highlights opportunities for process optimization in continuous casting operations. The alteration in filler sand composition resulted in an increase of up to 0.5% in the free opening rate

STEEL REMAINS THE MOST WIDELY USED INDUSTRIAL MATERIAL IN THE PRODUCTION OF CAPITAL AND CONSUMER GOODS, WITH APPLICATIONS SPANNING CIVIL CONSTRUCTION, INFRASTRUCTURE, MECHANICAL EQUIPMENT, METAL PRODUCTS, AUTOMOTIVE INDUSTRY, AND DOMESTIC APPLIANCES. SINCE 1950, GLOBAL STEEL PRODUCTION HAS GROWN STEADILY, REACHING APPROXIMATELY 1.88 BILLION TONNES OF CRUDE STEEL IN 2024. CURRENTLY, AROUND 96% OF GLOBAL STEEL OUTPUT IS PRODUCED VIA CONTINUOUS CASTING. IN BRAZIL, THE USE OF CONTINUOUS CASTING IS EVEN MORE PREDOMINANT, ACCOUNTING FOR APPROXIMATELY 99.5% OF NATIONAL STEEL PRODUCTION. THE OPERATIONAL EFFICIENCY OF CONTINUOUS CASTING RELIES HEAVILY ON THE PROPER SEQUENCING OF MOLTEN STEEL LADLES, WHICH DEPENDS ON ACHIEVING “FREE OPENING” OF THE LADLE GATE VALVE—THAT IS, THE IMMEDIATE FLOW OF STEEL UPON VALVE ACTIVATION. THIS STUDY AIMS TO QUANTIFY THE COSTS ASSOCIATED WITH THE OCCURRENCE OF “NON-FREE OPENING”—A CONDITION IN WHICH THE STEEL DOES NOT FLOW SPONTANEOUSLY THROUGH THE VALVE, REQUIRING OXYGEN INJECTION TO INITIATE THE FLOW. THE ANALYSIS COVERS MULTIPLE STEELMAKING ROUTES, GROUPED INTO FOUR MAIN CATEGORIES: SIMPLE ROUTE, RH ROUTE, DOUBLE REFINING, AND TRIPLE REFINING. THE STUDY EXAMINES THE INFLUENCE OF SAND COMPOSITION ON THE FREE OPENING RATE, ASSESSES THE FINANCIAL IMPLICATIONS OF FLOW INITIATION FAILURES, AND HIGHLIGHTS OPPORTUNITIES FOR PROCESS OPTIMIZATION IN CONTINUOUS CASTING OPERATIONS. THE ALTERATION IN FILLER SAND COMPOSITION RESULTED IN AN INCREASE OF UP TO 0.5% IN THE FREE OPENING RATE

Keywords

Filler sand composition, Free opening, Cost of a non-free opening, Continuous casting.

Filler sand composition, Free opening, Cost of a Non-free opening, Continuous casting