Chapter 25

List three categories of metallurgical processes.

Metal elements are found in both minerals and ores. Describe the difference between a mineral and an ore.

Ores contain minerals and gangue. Describe the difference between a mineral and gangue.

Calcination, roasting, and smelting are three pyrometallurgical processes. Compare and contrast the processes.

What compound has been historically used to leach gold from gold ores? Why is this process being discontinued?

Name three advantages of making metal components from the powder metallurgical process.

Describe the difference between body-centered cubic and facecentered cubic structures.

Describe the difference between a substitutional alloy and an interstitial alloy.

Both brass and bronze contain copper. Describe the difference between these two alloys.

List the properties of copper that make it appropriate for electric wires and the properties that make it appropriate for water pipes.

Describe three typical properties of metals.

Describe whether each property is generally higher or lower for metals compared to nonmetals. a. thermal conductivity b. electrical resistivity c. transparency d. ductility

List the name and formula of one important mineral source for each of these metals: Fe, Hg, \(\mathrm{V}\), and \(\mathrm{Nb}\).

List the name and formula of one important mineral source for each of these metals: \(\mathrm{Ti}, \mathrm{Zn}, \mathrm{U},\) and Ta.

$$ \text { Provide a general description of how hydrometallurgy is used to }$$ \text { extract metals from ores. } $$ $$

Provide a general description of how electrometallurgy is used to extract metals from ores.

Describe the difference between sponge-powdered iron and wateratomized powdered iron.

Describe the difference in the processing of sponge-powdered iron and water- atomized powdered iron.

Determine the composition of each vanadium alloy. a.One-half of the \(\mathrm{V}\) atoms are replaced by Cr atoms. b.One-fourth of the \(\mathrm{V}\) atoms are replaced by Fe atoms. c.One-fourth of the \(\mathrm{V}\) atoms are replaced by \(\mathrm{Cr}\) atoms, and one-fourth of the \(\mathrm{V}\) atoms are replaced by Fe atoms.

Determine the composition of each cobalt alloy. a. One-third of the Co atoms are replaced by Zn atoms. b. One-eighth of the Co atoms are replaced by Ti atoms. c. One-third of the Co atoms are replaced by Zn atoms, and one-sixth of the Co atoms are replaced by Ti atoms.

Identify the metal found in each mineral. a. sphalerite b. malachite c. hausmannite

Describe the effects of adding Mn to steel and give a use for manganese-steel alloys.

Why is it important to use an inert atmosphere to surround the metal when arc- melting titanium?

Describe how \(\mathrm{Zn}\) is used to protect the surface of steel products. What is the name of this process?

Describe the Bayer process.

How many lattice atoms surround a tetrahedral hole and an octahedral hole in a closest-packed structure? Describe which hole site is larger and explain why.

Co, \(\mathrm{Fe},\) and \(\mathrm{N}_{1}\) are ferromagnetic. What is the difterence between ferromagnetic and paramagnetic?

Iron powder is placed into a tall cylinder-shaped die and pressed from the top and bottom to make a cylinder-shaped pressed part with a height of \(5.62 \mathrm{~cm}\) and a radius of \(4.00 \mathrm{~cm} .\) The density of the iron powder before it was pressed was \(2.41 \mathrm{~g} / \mathrm{mL}\). The density of a pressed iron part is \(6.85 \mathrm{~g} / \mathrm{mL}\). The density of pure solid iron is \(7.78 \mathrm{~g} / \mathrm{mL}\) a. Calculate the original height of the powder before it was pressed. b. Calculate the theoretical height of the pressed component if it could be pressed to the same density of pure iron. c. What percentage of the pressed iron part is composed of voids between the iron particles?

When a part is made by pressing together powdered metal, no metal is wasted. In contrast, metal is typically scrapped after a metal part is cut from a solid metal plate. If a circular part with a diameter of \(10.0 \mathrm{~cm}\) is made from an original shape of a square with a side length of \(10.0 \mathrm{~cm},\) calculate the percentage of the metal that is thrown away as scrap. If the circular shape also has a circular hole with a diameter of \(6.0 \mathrm{~cm},\) calculate the percentage of the metal that is thrown away as scrap.

Create a table comparing and contrasting pyrometallurgy, hydrometallurgy, and electrometallurgy. Include a definition, an application or two, and any relevant notes for each type of metallurgy. Once your table is complete, pass it around your group asking each group member to read one cell from your table. Have other group members take turns trying to identify the type of metallurgy from the fact that is read aloud.

Would you expect an alloy of iron and vanadium to be substitutional or interstitial? Explain your choice. Create a phase diagram for the binary alloy of iron and vanadium based on the tabulated data provided. $$ \begin{array}{cc} \% \mathrm{~V} & \text { Melting Point } \\ 0 & 1530 \\ \hline 20 & 1480 \\ \hline 40 & 1470 \\ \hline 60 & 1560 \\ \hline 80 & 1720 \\ \hline 100 & 1900 \end{array} $$

Working individually, create a fill-in-the-blank question by rewriting a characteristic sentence or chemical reaction from Section \(25.5,\) but leaving out the name of the metal focused on in the content selected. Take turns sharing questions with the rest of the group. Take turns in the group trying to fill in the blank with the correct metal.