\n1. Raw Material Preparation
\n – Iron ore (lumps\/pellets with 65-68% Fe)
\n – Non-coking coal (as reductant & heat source)
\n – Dolomite\/limestone (as desulfurizing agent)<\/p>\n
The Tunnel Kiln Process for producing Sponge Iron (Direct Reduced Iron, DRI) in India is an alternative to the more common Rotary Kiln and Gas-Based DRI methods. This process is suitable for small to medium-scale production and is particularly useful where natural gas or high-grade coal is scarce.<\/p>\n
Tunnel Kiln Process for Sponge Iron Production in India
\n# 1. Overview
\n– The tunnel kiln is a continuous, straight furnace where iron ore (pellets\/lumps) and coal are loaded in crucibles or saggars.
\n– The charge moves slowly through different temperature zones (preheating, reduction, cooling) inside the kiln.
\n– Sponge iron is produced by solid-state reduction of iron ore using coal as a reductant.<\/p>\n
# 2. Key Steps in Tunnel Kiln Process
\n1. Raw Material Preparation
\n – Iron ore (lumps\/pellets with 65-68% Fe)
\n – Non-coking coal (as reductant & heat source)
\n – Dolomite\/limestone (as desulfurizing agent)<\/p>\n
2. Charging into Crucibles\/Saggars
\n – Alternate layers of iron ore and coal are loaded into refractory-lined crucibles.<\/p>\n
3. Movement Through Kiln Zones
\n – Preheating Zone (~800\u00b0C) \u2013 Moisture & volatile matter removal.
\n – Reduction Zone (~1050-1100\u00b0C) \u2013 Hematite (Fe\u2082O\u2083) reduces to magnetite (Fe\u2083O\u2084), then to wustite (FeO), and finally to sponge iron (~90-92% metallization).
\n – Cooling Zone \u2013 Reduced sponge iron is cooled before discharge.<\/p>\n
4. Discharge & Separation
\n – Sponge iron is separated from coal char and other residues.
\n – Magnetic separation may be used to improve purity.<\/p>\n
5. Briquetting (Optio![\"tunnel](\"\/img\/k-crusher.jpg\")
)
\n – Sponge iron fines can be briquetted for ease of handling.<\/p>\n
# 3. Advantages of Tunnel Kiln Process in India
\n\u2714 Suitable for small-scale plants (30,000\u2013100,000 TPA capacity).
\n\u2714 Lower capital cost compared to rotary kilns\/gas-based plants.
\n\u2714 Can use low-grade non-coking coal (abundant in India).
\n\u2714 Better control over reduction conditions compared to rotary kilns<\/p>\n","protected":false},"excerpt":{"rendered":"
The Tunnel Kiln Process for producing Sponge Iron (Direct Reduced Iron, DRI) in India is an alternative to the more common Rotary Kiln and Gas-Based DRI methods. This process is suitable for small to medium-scale production and is particularly useful where natural gas or high-grade coal is scarce. Tunnel Kiln Process for Sponge Iron Production […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[40],"tags":[],"class_list":["post-8735","post","type-post","status-publish","format-standard","hentry","category-product-news"],"_links":{"self":[{"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/posts\/8735","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/comments?post=8735"}],"version-history":[{"count":0,"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/posts\/8735\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/media?parent=8735"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/categories?post=8735"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zwccrusher.com\/index.php\/wp-json\/wp\/v2\/tags?post=8735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}