Question

Almost all metals in nature are found as ionic compounds in ores instead of being in the pure state. Why? What must be done to a sample of ore to obtain a metal substance that has desirable properties?

Short answer

Metals in nature are typically found as ionic compounds in ores since they are chemically reactive and tend to form more stable ion-containing compounds, such as metallic oxides, sulfides, or carbonates. To obtain a pure metal from its ore, the ore must undergo a series of processes, including concentration, reduction, and purification or refining. Concentration involves separating the metal-containing compounds from impurities, reduction involves removing oxygen or other non-metal elements, and purification or refining ensures the desired level of purity and properties is achieved.

Step-by-step solution

Reason for metals being ionic compounds in ores

Metals in nature are usually found as ionic compounds in ores because they are chemically reactive elements. This means that, over time, metals in their pure state tend to react with other elements in their environment to form more stable ion-containing compounds like metallic oxides, sulfides or carbonates. This prevents the metals from existing in their pure state for extended periods in nature.

Process for obtaining metal from ore

To obtain a pure metal substance with desirable properties from its ore, the ore must undergo a series of processes such as concentration, reduction, and purification or refining. Here's a breakdown of each step.

1. Concentration

The first step is to separate the metal-containing compounds from the impurities and unwanted materials present in the ore. This can be done through processes like gravity separation, froth flotation, or magnetic separation, depending on the characteristics of the ore and the metal being extracted.

2. Reduction

After concentrating the metal-containing compound, it must be reduced to obtain the pure metal. Reduction involves removing the oxygen or other non-metal elements from the metal-containing compounds. This can be done through a variety of processes, such as chemical reduction using a reducing agent (e.g., carbon), electrolytic reduction using electricity or thermite process which involves using a reactive metal like aluminum to reduce the metal ion to its pure form.

3. Purification or refining

Finally, the extracted metal must be further purified or refined to obtain the desired level of purity and properties. This can be achieved through different methods, such as electrolysis, zone refining, vapor phase refining, or pyrometallurgical refining. The choice of the refining method depends on the specific metal, its properties, and the desired level of purity. After completing these steps, we obtain a pure metal substance with desirable properties that can then be used for various applications.