Metal Extraction: Pyrometallurgy (Module 1-5)

Question 1

It involves the chemical processing of a concentrate when all physical processes are no longer possible to separate the unwanted elements or portions.

Answer 1

Metal Extraction

Question 2

Metal extraction may lead to what three results?

Answer 2

a. Metal Production
b. Compound Formation
c. Metal Purification

Question 3

What are the three additional branches of extractive metallurgy?

Answer 3

a. Pyrometallurgy
b. Hydrometallurgy
c. Electrometallurgy

Question 4

It deals with high-temperature, non-aqueous reactions; and it uses thermodynamic data to predict whether a set of given reactions proceed and and to predict the effect of changing temperature in the course of a reaction.

Answer 4

High-Temperature Processing or Pyrometallurgy

Question 5

What are the three most common equipment in pyrometallurgy?

Answer 5

Ovens, Kilns, and Furnaces

Question 6

Why does pyrometallurgical processes require pre-treated or preconcentrated charge?

Answer 6

To avoid wastage of energy

Question 7

Chemical reaction rates, as well as mass transport of reactants, increases with what?

Answer 7

Temperature

Question 8

T/F: Pyrometallurgical processes result to low throughputs of materials.

Answer 8

False. Pyrometallurgical processes result to high throughput of materials.

Question 9

Solubility of any species in a particular phase increases with increasing temperature.

T/F: This leads to a reduction in the selectivity of the operation.

Answer 9

True.

Question 10

T/F: Pyrometallurgical processes require very low energy outputs.

Answer 10

True

Question 11

What are the six pyrometallurgical operations?

Answer 11

a. Drying
b. Calcination
c. Roasting
d. Sintering
e. Smelting
f. Converting

Question 12

It is the driving off excess moisture by elevating the temperature, or in some cases, by a chemical treatment.

Answer 12

Drying

Question 13

It is the decomposition of carbonates into oxides and carbon dioxide by heating.

Answer 13

Calcination

Question 14

This is also used to describe the process in which chemically combined water is driven off from oxide and carbonate ores and clays.

Answer 14

Calcination

Question 15

T/F: Drying and calcination usually takes place inside a rotary kiln abd fluidised bed.

Answer 15

True

Question 16

It is the process of heating the ore in the air to an elevated temperature which makes sulfur and other certain impurities to pass off as gases.

Answer 16

Roasting

Question 17

This process is commonly done to sulfide ores.

Answer 17

Roasting

Question 18

It is the agglomeration by means of heat.

Answer 18

Sintering

Question 19

This process results to a porous and spongy material, giving it a large surface area necessary for speed in subsequent reduction. This is commonly done to iron ores.

Answer 19

Sintering

Question 20

T/F: Roasting usually takes place in multiple hearth furnace and fluo-solid furnace.

Answer 20

True

Question 21

It is the process of reducing a metallic ore to crude metal. It is also the process of melting and separating two immiscible liquid layers of metal and slag.

Answer 21

Smelting

Question 22

Smelting utilizes what material to lower the melting point of the gangue

Answer 22

Flux

Question 23

It is produced by smelting sulfides. It is the mixture of molten sulfides and not of the molten metal.

Answer 23

Matte

Question 24

It is the product resulting from the action of a flux on the nonmetallic constituents of a processed ore.

Answer 24

Slag

Question 25

It is the non-valuable constituent of a pyrometallurgical process.

Answer 25

Slag

Question 26

It is the solution of various sulfides, usually of copper, iron, and nickel.

Answer 26

Matte

Question 27

These are artificial solutions of arsenides or a combination of arsenides and antimonides. These are commonly found for ores containing large amounts of arsenic and antimony.

Answer 27

Speiss

Question 28

It is the mixture of products usually found floating on the surface of liquid metals.

Answer 28

Dross

Question 29

This is the reduced metal in liquid form and the product we usuallly want to get.

Answer 29

Molten Metal

Question 30

What are the three functions of the slag?

Answer 30

a. Protection from contamination
b. Acquisition of unwanted impurities
c. Control on the supply of refining agents
d. Insulation of the melt

Question 31

What are the properties of the slag?

Answer 31

a. Lower melting point than the melt
b. Low viscosity to avoid entrapment
c. Lower density
d. Immiscibility
e. Suited to acceptance and retention of impurities

Question 32

What are the five phases of pyrometallurgical systems?

Answer 32

a. Slag
b. Matte
c. Speiss
d. Dross
e. Molten Metal

Question 33

Under what condition is matte smelting done?

Answer 33

Neutral or slightly reducing conditions

Question 34

T/F: Matte smelting is done at higher temperatures than oxide smelting.

Answer 34

False. Matte smelting is done at lower temperatures than oxide smelting.

Question 35

T/F: A considerable amount of the matte separates into the slag.

Answer 35

True

Question 36

This can be considered as a concentrating stage in metal extraction from sulfide ores.

Answer 36

Matte Smelting

Question 37

What are the two common equipment for sulfide (or matte) smelting?

Answer 37

a. Flash Furnace

b. Reverbatory Furnace

Question 38

This is the next step after matte smelting. This involves blowing air to a molten matte, causing selective oxidation of the more reactive impurity sulfides to their respective oxides which are then transferred to the slag.

Answer 38

Converting

Question 39

A common equipment for matte converting.

Answer 39

Horizontal Converter

Question 40

This pyrometallurgical operation is done for oxide ores (iron). It is carried out with “coke” when the ore is in lump or agglomerated form. It is also usually carried out in a blast furnace.

(Coke is a porous fuel with high carbon content)

Answer 40

Metal Oxide Smelting