Which of the following ore is concentrated using group 1 cyanide salt?

We need to identify the ore that is concentrated using a Group 1 cyanide salt (such as NaCN or KCN).

In metallurgy, NaCN is used as a depressant in the froth flotation process. Specifically, when separating a mixture of ZnS (sphalerite) and PbS (galena), NaCN is added to selectively depress ZnS.

NaCN reacts with ZnS on the surface to form $$Na_2[Zn(CN)_4]$$, a soluble complex. This prevents ZnS from being wetted by the collector (xanthate), so ZnS sinks while PbS floats with the froth.

Among the given options: Malachite is a copper carbonate ore, Calamine is a zinc carbonate ore, Siderite is an iron carbonate ore, and Sphalerite is zinc sulphide (ZnS).

Sphalerite (ZnS) is the ore that is concentrated using NaCN in the froth flotation process.

Hence, the correct answer is Option 4.