Why is there a concern about copper smelting plants? 1. They may release lethal quantities of carbon monoxide into environment. 2. The copper slag can caus

1. A. 1 and 2 only
2. B. 2 and 3 only
3. C. 1 and 3 only
4. D. 1, 2 and 3

Answer: B

Explanation

Smelting is a process of applying heat to ore in order to extract a base metal. The copper concentrates are fed through the flash smelting furnace with oxygen-enriched air. In the furnace, the concentrates are instantly oxidized, after which they melt and separate by their own reaction heat into copper matte with a grade of 65% and slag consisting of iron oxide, silica, and other compounds. Extractive metallurgical and smelting processes can be highly polluting activities. Some facilities that carry out metal and smelting processes are known to emit high quantities of air pollutants such as hydrogen fluoride, sulfur dioxide, oxides of nitrogen, offensive and noxious smoke fumes, vapors, gases, and other toxins. Due to the application of pyro-metallurgical processes in copper smelters, significant air pollution occurs with suspended particles. These particles contain high concentrations of Lead (Pb), Cadmium (Cd), Nickel (Ni) and Arsenic (As). Copper slag can have heavy metals like cobalt, zinc, arsenic, lead, cadmium, barium etc. Slag can release these elements into the environment under natural weathering conditions and cause pollution of soils, surface waters and groundwater. Hence, statement 2 is correct. Organic vapors and sulfur oxides resulting from secondary smelting roasting operations and fuel combustion can cause smog, containing ozone, fine airborne particles, nitrogen oxides, sulfur dioxide and carbon monoxide. Carbon monoxide poisoning typically occurs from breathing in carbon monoxide (CO) at excessive levels. Hence, statement 1 is not correct and 3 is correct.