What type of kiln does this code cover?

It covers vertical mixed-feed type kilns used for the continuous calcination of limestone.

What is the ideal fuel to use in vertical mixed-feed kilns?

Hard coke or low-ash steam coal is preferred to minimize ash contamination of the final lime product.

Why must fines be removed from the limestone feed?

Fines restrict the upward flow of combustion gases, causing uneven burning, localized heating, and draft issues.

IS 1861

: 2000

Guide for the manufacture of lime in vertical mixed-feed type kiln, Part 1: From lime-stone

CurrentSpecializedGuidelinesMaterials Science · Building Limes and Gypsum Products

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Provides guidelines for manufacturing building lime from limestone using a vertical mixed-feed type kiln. It outlines requirements for raw materials, fuel properties, kiln design proportions, and standard operational practices for efficient calcination.

Guide for the manufacture of lime in vertical mixed-feed type kiln, Part 1: From lime-stone

Quick Reference Values

Limestone feed size50 mm to 150 mm

Calcination temperature900°C to 1100°C

Preferred max ash content in coal20% to 25%

Practical Notes

Proper distribution of coal and limestone is critical to maintain a uniform temperature profile and avoid clinker formation.

Fines must be strictly screened out before feeding into the kiln to prevent the blockage of draft and air flow.

Draft control (natural or forced) directly impacts the calcination efficiency and fuel consumption.