Open-hearth furnace. Encyclopædia Britannica, Inc. Natural gas or atomized heavy oils are used as fuel; both air and fuel are heated before combustion. The furnace is charged with liquid blast-furnace iron and steel scrap together with iron ore, limestone, dolomite, and fluxes.

A rotary hearth furnace is a direct-reduction device that enables to recover valuable metals from dust produced during the steelmaking process, as well as to produce direct-reduced iron from fine ore. Steel mills generate various kinds of dust that are produced during the steelmaking process.

Compared to Bessemer steel, which it displaced, its main advantages were that it did not expose the steel to excessive nitrogen (which would cause the steel to become brittle), was easier to control, and permitted the melting and refining of large amounts of scrap iron and steel.

Normally, the refractory lining of the conventional blast furnace is made by carbon or graphite blocks. Carbon and graphite is ideal for this particular application because both of them are not wet by hot metal.

The furnace. The open-hearth furnace (OHF) uses the heat of combustion of gaseous or liquid fuels to convert a charge of scrap and liquid blast-furnace iron to liquid steel. The high flame temperature required for melting is obtained by preheating the combustion air and, sometimes, the fuel gas.

A steelmaking process employing an open-hearth furnace lined with siliceous-type refractories.

Sir William Siemens

A basic oxygen furnace (BOF) is a vessel used to convert hot metal into steel. During the process, oxygen is blown into a BOF converter containing liquid hot metal containing high carbon content. The oxygen combines with the dissolved carbon to form CO, which then escapes as gas.

The majority of steel manufactured in the world is produced using the basic oxygen furnace. In 2000, it accounted for 60% of global steel output. Modern furnaces will take a charge of iron of up to 400 tons and convert it into steel in less than 40 minutes, compared to 10–12 hours in an open hearth furnace.

Blast furnace-basic oxygen furnace uses iron ore as its base raw material that accounts over just 50% of BOF steel costs, and electric arc furnace uses scrap as its base that represents around 75% of EAF steel cost. The Basic Oxygen Steelmaking process differs from the EAF is that BOF is self-sufficient in energy.

The basic oxygen furnace (BOF) is a vessel used to convert pig iron, of about 94 percent iron and 6 percent combined impurities such as carbon, manganese, and silicon, into steel with as little as 1 percent combined impurities.

Furnace Charge means the material melted in the furnace.

Basic oxygen process (BOP), a steelmaking method in which pure oxygen is blown into a bath of molten blast-furnace iron and scrap. The oxygen initiates a series of intensively exothermic (heat-releasing) reactions, including the oxidation of such impurities as carbon, silicon, phosphorus, and manganese.

The furnace charge, or burden, of iron-bearing materials (e.g., iron-ore pellets and sinter), coke, and flux (e.g., limestone) descends through the shaft, where it is preheated and reacts with ascending reducing gases to produce liquid iron and slag that accumulate in the hearth.

The reaction between oxygen and carbon is exothermic and is responsible for increasing the temperature of the blast furnace.

Add Fuel to the Blast Furnace In this tutorial, we are going to use coal as our fuel. TIP: Some fuels burn longer than others and therefore can smelt more items.

Blast Furnaces should be able to smelt sand, Netherrack, cobblestone, and stone-related blocks faster, not just ores. Normal furnaces should be just a low-tier furnace for the first hours of a world, and they should be replaced by smokers and blast furnaces.