An ore gives carbon dioxide gas on heating in absence of air . Identify the ore and write its stepsof metallurgy

The ore that gives off carbon dioxide gas when heated in the absence of air is likely to be a carbonate ore. The most common example of this is limestone (calcium carbonate), but other examples include siderite (iron(II) carbonate) and zinc carbonate.

The steps of metallurgy for a carbonate ore are as follows:

1. Mining and Collection: The first step is to physically extract the ore from the earth. This is done through a process called mining. The ore is then collected and prepared for the next step.

2. Concentration of Ore: This step involves removing the impurities from the ore. This is often done through a process called froth flotation, where the ore is crushed and mixed with water and detergents. The ore particles stick to the bubbles and float to the top, where they can be collected.

3. Conversion of Ore into Oxide: Carbonate ores are heated in the absence of air to convert them into oxides. This process is known as calcination. For example, calcium carbonate would be heated to form calcium oxide and carbon dioxide.

   CaCO3(s) → CaO(s) + CO2(g)

4. Reduction of Ore: The oxide is then reduced to extract the metal. This is often done using carbon, as it is a cheap and abundant reducing agent. For example, calcium oxide can be reduced to calcium metal by heating it with carbon.

   CaO(s) + C(s) → Ca(s) + CO(g)

5. Refining: The final step is to purify the metal. This can be done through a variety of methods, including electrolysis and zone refining, depending on the specific metal and its properties.

These are the general steps for the metallurgy of a carbonate ore. The specific steps can vary depending on the specific ore and the metal being extracted.