The Bessemer's Converter Process Explained.

Summary

The Bessemer Converter Process revolutionized steel production by providing the first inexpensive industrial method for mass production from molten pig iron. Named after Sir Henry Bessemer of England, this method involved blowing air through molten iron to oxidize impurities like silicon, manganese, and carbon, transforming them into gases or solid slag. Despite its initial limitations, like the inability to remove phosphorus effectively, the process improved with innovations like the Thomas-Gilchrist converter. Though eventually replaced by the basic oxygen process in the mid-20th century, Bessemer's process laid the foundation for modern steelmaking practices.

Highlights

• Sir Henry Bessemer's namesake process dramatically lowered steel production costs. 🏗️
• Oxidation is central to this process, removing impurities from molten iron with blown air. 🌪️
• The original process struggled with phosphorus removal, affecting steel quality. 👀
• Sydney Gilchrist Thomas' innovation with basic lining improved phosphorus extraction. 🔧
• Bessemer's method ultimately gave way to more advanced steel making processes. ⏭️

Key Takeaways

• The Bessemer Converter was a game-changer for mass-producing steel economically. 💡
• This process made use of air to oxidize impurities away from molten pig iron. 🌬️
• Despite initial challenges, advancements like the Thomas-Gilchrist converter improved its efficiency. 🚀
• The Bessemer process was pivotal until the mid-20th century before being overtaken by the basic oxygen process. 🔄
• Phosphate fertilizer was a valuable byproduct of the process, thanks to the slag. 🌿

Overview

The Bessemer Converter Process shook up the steel industry by providing a cost-effective way to produce steel on a massive scale from pig iron. By introducing air into the molten metal, the process facilitated the oxidation of impurities like silicon, manganese, and carbon, transforming them into gas or solid slag. Initially limited in dealing with phosphorus, which affected the quality of steel produced, the process was gradually improved through additional innovations.

One of the most noteworthy advancements was the invention by Sydney Gilchrist Thomas, who introduced a basic lining material to the conversion process. This improved the effectiveness of removing phosphorus, thus elevating the quality of the steel. Despite issues like nitrogen retention, which were not resolved until much later, the Bessemer process was instrumental in leading developments in steel manufacturing throughout the late 19th and early 20th centuries.

Eventually, the Bessemer method was surpassed by the open hearth process and later by the basic oxygen process, each offering further refinements and efficiencies. Yet, the legacy of the Bessemer Converter Process remains significant, having paved the way for modern advancements in steel production and even offering profitable byproducts in the form of phosphate fertilizers.

Chapters

• 00:00 - 00:30: Introduction to Bessemer's Converter Process This chapter introduces Bessemer's Converter Process, highlighting its significance as the first cost-effective industrial method for large-scale steel production from molten pig iron. It precedes the open hearth furnace development and is named after Sir Henry Bessemer.
• 00:30 - 01:00: Development and Invention The chapter titled 'Development and Invention' discusses the evolution of a process that was created independently by Bessemer of England and William Kelly of the United States. The Bessemer converter, a key part of this process, is a large cylindrical steel pot initially lined with a siliceous refractory. Air is blown in through openings near the bottom, which aids in the commercial application of the invention.
• 01:00 - 01:30: Operation and Mechanism The chapter discusses the production of steel using the Bessemer converter, focusing on the oxidation process that removes impurities from iron. It describes how silicon, manganese, and carbon form oxides and become part of the slag or are carried out in the air stream. Within minutes, steel ingots are ready for further processing.
• 01:30 - 02:00: Oxidation and Impurity Removal In this chapter, the process of oxidation and impurity removal in metallurgy is explained. Air is blown through molten pig iron, introducing oxygen that oxidizes and removes impurities such as silicon, manganese, and carbon, which form oxides. These oxides either escape as gas or form a solid slag. The refractory lining of the converter aids this process, with clay linings being used when there is minimal phosphorus in the raw materials.
• 02:00 - 02:30: Challenges and Innovations This chapter discusses the challenges faced in steel production due to the high phosphorus content in British and European iron. The original Bessemer Converter was not effective in removing phosphorus, leading to low-quality steel. The innovation came with the invention of the Thomas Gilchrist Converter by Sydney Gilchrist Thomas in England. This converter was lined with basic materials like burned limestone, dolomite, or sometimes magnesite, which effectively addressed the phosphorus issue and improved steel quality.
• 02:30 - 03:00: The Thomas-Gilchrist Converter The chapter discusses the Thomas-Gilchrist Converter, which offered a solution to a specific problem in steelmaking related to acidic materials. It highlights the drawback of the Bessemer converter steel, specifically its retention of nitrogen from the air, a problem not resolved until the 1950s. In contrast, the open hearth process developed in the 1860s did not face this problem and eventually surpassed the Bessemer process to become the leading steelmaking method until the mid-20th century.
• 03:00 - 03:30: Comparative Industrial Processes The chapter discusses the evolution of industrial processes in steelmaking, particularly focusing on the transition from the open hearth process to the basic oxygen process. The basic oxygen process is described as an extension and refinement of the Bessemer process. In the Bessemer converter, a batch of hot metal weighing between 5 to 30 tons could be treated at a time. These converters were typically operated in pairs, with one being blown while the other was being filled or tapped. A significant advantage of the basic converter was its ability to form more slag, which could be recovered and used effectively.
• 03:30 - 04:00: Operational Details and Advantages The chapter discusses the operational details and advantages of using phosphate fertilizer. It explores how phosphate fertilizers are profitable and beneficial for agricultural purposes.

The Bessemer's Converter Process Explained. Transcription

• 00:00 - 00:30 [Music] besser's converter process the besser process was the first inexpensive industrial process for the mass production of Steel from molten pig iron before the development of the open half furnace though named after Sir Henry
• 00:30 - 01:00 besser of England the process evolved from the combination of many investigator before it could be used on a broad commercial basis it was apparently conceived independently and almost concurrently by besser and by William Kelly of the United [Music] States the besser's converter is a cylindrical steel pot approximately 6 M 20 ft High originally lined with a celicious refractory air is blown in through opening 2 years near the bottom
• 01:00 - 01:30 creating oxides of silicon and manganese which become part of the slag and of carbon which are carried out in the Stream of air within a few minutes an Ingot of Steel can be produced ready for the forge or rolling Mills the key principle of the besser converter is removal of impurities from the Iron by oxidation with air being blown through the molten iron the oxidation
• 01:30 - 02:00 the blowing of air through the molten pigion introduces oxygen into the Melt which results in oxidation removing impurities formed in the pig ions such as silicon manganese and carbon in the form of oxides these oxides either escapes as gas or form a solid slag the refractory lining of the converter also plays a role in the conversion clay lining are used where there is little phosphorus in the Raw
• 02:00 - 02:30 material this is known as the acid besser process when the phosphorus content is high the original bessus converter was not effective in removing the phosphorus present in most British and European iron or this led to the production of lowquality Steels the invention in England by Sydney Gilchrist Thomas of what is now called the Thomas Gilchrist converter which was lined with a basic material such as burned Limestone Dolomite or sometimes magnesite
• 02:30 - 03:00 rather than an acid celicious material overcame the problem another draw back to bessma converter steel is its retention of a small percentage of nitrogen from the air blow this was not corrected until the 1950s the open half process which was developed in the 1860s did not suffer this difficulty and it eventually outstripped the bessma process to become the dominant steel making process until the mid 20th century
• 03:00 - 03:30 the open half process was in turn replaced by the basic oxygen process which is actually an extension and refinement of the besser's process a besser's converter could treat a heat batch of hot metal of 5 to 30 tons at a time they were usually operated in pairs one being blown while another was being filled or tapped an additional advantage of the basic converter was that the process formed more slag in the converter and this could be recovered and used very
• 03:30 - 04:00 profitable as a phosphate fertilizer [Music]