Fine particles of raw materials, such as iron ore or limestone can be difficult to transport because they are dusty. Additionally, lumps of raw materials have mechanical and chemical properties that can impact the reaction in blast furnaces. These powdery materials are thus usually agglomerated into larger pieces for transport and use. The raw material’s properties determine the agglomeration process that is used by mills.

Sinter

Iron ore particles that are stuck together in roughly 3-4cm chunks through heat treatment. In a blast furnace, these improve gas flow and, thus, improve the rate of reaction over iron ore dust. These are created in sinter plants

Pellets

Pellets are created in pelletising plants. Iron ore or limestone particles are rolled into little balls in a 'balling drum', and are subsequently through a heating process.

Briquettes

Briquettes are small lumps that are formed by pressing material together. Hot Briquetted Iron (HBI) is a concentrated iron ore substitute made of scrap for use in electric furnaces.

Steel ls fundamentally an alloy of iron with small amounts of carbon. However, other elements, both metallic and non-metallic, can be added to change the properties of the steel, increasing corrosion resistance, hardness, or strength and so on. 

There are perhaps twenty elements that can be alloyed with steel, imparting various properties as a result. These result in different 'grades' of steel. 

Examples of (metallic) alloying elements include:

• Aluminium: used to purge steel of impurities, such as oxygen, phosphorous or sulphur
  
• Chromium: increases toughness, hardness and wear resistance; widely used in stainless steels
• Copper: increases corrosion resistance and hardness
• Manganese: increases high-temperature strength, wear resistance, ductility and hardness
• Molybdenum: adds corrosion resistance and improves high-temperature strenth; widely used in stainless steels
• Nickel: increases corrosion resistance and strength; widely used in stainless steels
• Silicon: improves magnetism and strength
• Tungsten: used to increase strength and hardness
• Vanadium: improves corrosion resistance and material strength

Less commonly used alloying elements can impart other properties. These bismuth, cobalt, titanium, selenium, tellurium, lead, boron, sulfur, nitrogen, zirconium and niobium. These alloying elements can be used alone or mixed depending on the intended characteristics of the alloy steel being created.

Steel is commonly called 'carbon' steel because it is an alloy comprising mostly iron combined with a small proportion of carbon. However, other alloying elements are often added. These added elements provide the steel additional characteristics, such as improved ductility, strength or corrosion resistance. These are added during the smelting process, and make 'alloy' steel.

Non-alloy steel has no elements added to the steel as it is smelted - hence the name.

Alloy steel is steel that has been mixed with one or more alloying elements to impart specific properties. 

Strictly speaking, all steels are an alloy because steel is already an alloy of iron and a small amount of carbon (between 0.04% and 1.5%), but not all steels are called 'alloy steels'.

The term 'alloy steel' refers to steel mixed - alloyed - with other alloying elements deliberately, in addition to the carbon. Common alloying elements include manganese, nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloying elements include aluminium, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, and zirconium.

Steel is an amazingly versatile material that has applications ranging from cutlery and cars, to scissors and skyscrapers. It is everywhere in our daily lives.

On a metallurgical level, steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, sulphur and oxygen. Steel is the world's most important engineering and construction material. It is used in every aspect of our lives; in cars and construction products, refrigerators and washing machines, cargo ships and surgical scalpels.

Steel is the most versatile industrial material in the world. The thousands of different grades and types of steel developed by the industry make the modern world possible. Steel is 100% recyclable and therefore is a fundamental part of the circular economy. As a basic engineering material, steel is also an essential factor in the development and deployment of innovative, CO2-mitigating technologies, improving resource efficiency and fostering sustainable development in Europe.

About 1.8 billion tonnes per year.

China is by far the largest producer in the world, making around a billion tonnes a year. The EU is the second largest producer, outputting 170 million tonnes a year

Most steel in Europe is produced via two basic routes: The Blast Furnace-Basic Oxygen Furnace (BF-BOF) route and the Electric Arc Furnace route (EAF). Blast furnaces produce iron from iron ore. In a second step a basic oxygen converter turns iron, with some additions of scrap, into steel. Electric Arc Furnaces produce steel mostly from scrap collected for recycling.