Extraction of zinc from zinc blende is achieved by (A) electrolytic reduction (B) roasting followed by reduction with carbon (C) roasting followed by reduction with another metal (D) roasting followed by self-reduction

The process of roasting represents a critical step in the metallurgical extraction of metals from their natural mineral compounds. In regards to zinc blende, which primarily consists of zinc sulfide (ZnS), the goal of roasting is to convert the sulfide into its oxide form. This conversion is a chemical reaction that occurs when ore is heated in the presence of oxygen - a key component of air.

During the roasting of zinc blende, the chemical equation \[2\text{ZnS} + 3\text{O}_2 \rightarrow 2\text{ZnO} + 2\text{SO}_2\] illustrates how zinc sulfide (ZnS) reacts with oxygen (O2) to form zinc oxide (ZnO) and sulfur dioxide (SO2). This step is vitally important because it not only eliminates the sulfur but also prepares the compound for the next stage - reduction. The sulfur dioxide by-product can be further processed and utilized, emphasizing the efficiency and environmental consideration within metallurgical processes.

Following roasting, the next phase in the extraction of zinc involves the reduction of the produced zinc oxide (ZnO). This part of the process employs carbon as a reducing agent.

Carbon, often in the form of coke, is used because of its ability to take away the oxygen from zinc oxide, leaving behind pure zinc metal. The reduction reaction can be represented by the formula: \[\text{ZnO} + \text{C} \rightarrow \text{Zn} + \text{CO}\]. This indicates that when zinc oxide and carbon are heated together at high temperatures, elemental zinc is produced, along with carbon monoxide as a by-product. This particular step is not only essential for yielding the metallic state of zinc but is also one of the more energy-intensive parts of the zinc extraction process, requiring careful control of temperature and time to ensure efficiency and cost-effectiveness.

Metallurgical processes encompass the totality of operations involved in the extraction and processing of metals from their ores. In the case of zinc extraction from zinc blende, the metallurgical processes include roasting, reduction and potentially further purification methods such as electrolysis.

Each stage of the process has its unique conditions and requirements. For example, roasting demands a controlled supply of air to ensure complete oxidation, while reduction with carbon requires high temperatures and the careful handling of by-products like sulfur dioxide and carbon monoxide. Safety, environmental impact, and cost-effectiveness are key considerations governing these processes.

Innovations and technological advancements continue to refine these methods, aiming to improve yield, reduce energy consumption, and mitigate environmental effects. In essence, the science of metallurgy is about finding the most efficient pathways from ore to usable metal, a principle that underlines every step in the extraction of zinc from zinc blende.

The initial raw material for zinc production is the mineral zinc blende, composed mainly of zinc sulfide (ZnS). Processing this mineral begins with extraction operations such as mining, followed by concentration to increase the ZnS content in the ore.

Subsequently, as part of the processing, zinc sulfide undergoes roasting to transform it into an oxide which can then be reduced by carbon. These steps, collectively known as processing, adhere to the principles of metallurgical operations designed to efficiently and safely convert raw material into a state that contains the metal in its usable form.

The zinc extraction process not only has to consider the chemical and physical properties of zinc but also the economic viability and environmental impact. By carefully controlling and optimizing each stage of the ZnS processing, it becomes possible to extract zinc effectively, important for its wide-ranging applications in industry, from galvanization to the manufacture of alloys.